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stallion.c

/*****************************************************************************/

/*
 *    stallion.c  -- stallion multiport serial driver.
 *
 *    Copyright (C) 1996-1999  Stallion Technologies
 *    Copyright (C) 1994-1996  Greg Ungerer.
 *
 *    This code is loosely based on the Linux serial driver, written by
 *    Linus Torvalds, Theodore T'so and others.
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*****************************************************************************/

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial.h>
#include <linux/cd1400.h>
#include <linux/sc26198.h>
#include <linux/comstats.h>
#include <linux/stallion.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/smp_lock.h>
#include <linux/device.h>
#include <linux/delay.h>

#include <asm/io.h>
#include <asm/uaccess.h>

#ifdef CONFIG_PCI
#include <linux/pci.h>
#endif

/*****************************************************************************/

/*
 *    Define different board types. Use the standard Stallion "assigned"
 *    board numbers. Boards supported in this driver are abbreviated as
 *    EIO = EasyIO and ECH = EasyConnection 8/32.
 */
#define     BRD_EASYIO  20
#define     BRD_ECH           21
#define     BRD_ECHMC   22
#define     BRD_ECHPCI  26
#define     BRD_ECH64PCI      27
#define     BRD_EASYIOPCI     28

/*
 *    Define a configuration structure to hold the board configuration.
 *    Need to set this up in the code (for now) with the boards that are
 *    to be configured into the system. This is what needs to be modified
 *    when adding/removing/modifying boards. Each line entry in the
 *    stl_brdconf[] array is a board. Each line contains io/irq/memory
 *    ranges for that board (as well as what type of board it is).
 *    Some examples:
 *          { BRD_EASYIO, 0x2a0, 0, 0, 10, 0 },
 *    This line would configure an EasyIO board (4 or 8, no difference),
 *    at io address 2a0 and irq 10.
 *    Another example:
 *          { BRD_ECH, 0x2a8, 0x280, 0, 12, 0 },
 *    This line will configure an EasyConnection 8/32 board at primary io
 *    address 2a8, secondary io address 280 and irq 12.
 *    Enter as many lines into this array as you want (only the first 4
 *    will actually be used!). Any combination of EasyIO and EasyConnection
 *    boards can be specified. EasyConnection 8/32 boards can share their
 *    secondary io addresses between each other.
 *
 *    NOTE: there is no need to put any entries in this table for PCI
 *    boards. They will be found automatically by the driver - provided
 *    PCI BIOS32 support is compiled into the kernel.
 */

typedef struct {
      int         brdtype;
      int         ioaddr1;
      int         ioaddr2;
      unsigned long     memaddr;
      int         irq;
      int         irqtype;
} stlconf_t;

static stlconf_t  stl_brdconf[] = {
      /*{ BRD_EASYIO, 0x2a0, 0, 0, 10, 0 },*/
};

static int  stl_nrbrds = ARRAY_SIZE(stl_brdconf);

/*****************************************************************************/

/*
 *    Define some important driver characteristics. Device major numbers
 *    allocated as per Linux Device Registry.
 */
#ifndef     STL_SIOMEMMAJOR
#define     STL_SIOMEMMAJOR         28
#endif
#ifndef     STL_SERIALMAJOR
#define     STL_SERIALMAJOR         24
#endif
#ifndef     STL_CALLOUTMAJOR
#define     STL_CALLOUTMAJOR  25
#endif

/*
 *    Set the TX buffer size. Bigger is better, but we don't want
 *    to chew too much memory with buffers!
 */
#define     STL_TXBUFLOW            512
#define     STL_TXBUFSIZE           4096

/*****************************************************************************/

/*
 *    Define our local driver identity first. Set up stuff to deal with
 *    all the local structures required by a serial tty driver.
 */
static char *stl_drvtitle = "Stallion Multiport Serial Driver";
static char *stl_drvname = "stallion";
static char *stl_drvversion = "5.6.0";

static struct tty_driver      *stl_serial;

/*
 *    Define a local default termios struct. All ports will be created
 *    with this termios initially. Basically all it defines is a raw port
 *    at 9600, 8 data bits, 1 stop bit.
 */
static struct termios         stl_deftermios = {
      .c_cflag    = (B9600 | CS8 | CREAD | HUPCL | CLOCAL),
      .c_cc       = INIT_C_CC,
};

/*
 *    Define global stats structures. Not used often, and can be
 *    re-used for each stats call.
 */
static comstats_t stl_comstats;
static combrd_t         stl_brdstats;
static stlbrd_t         stl_dummybrd;
static stlport_t  stl_dummyport;

/*
 *    Define global place to put buffer overflow characters.
 */
static char       stl_unwanted[SC26198_RXFIFOSIZE];

/*****************************************************************************/

static stlbrd_t         *stl_brds[STL_MAXBRDS];

/*
 *    Per board state flags. Used with the state field of the board struct.
 *    Not really much here!
 */
#define     BRD_FOUND   0x1

/*
 *    Define the port structure istate flags. These set of flags are
 *    modified at interrupt time - so setting and reseting them needs
 *    to be atomic. Use the bit clear/setting routines for this.
 */
#define     ASYI_TXBUSY 1
#define     ASYI_TXLOW  2
#define     ASYI_DCDCHANGE    3
#define     ASYI_TXFLOWED     4

/*
 *    Define an array of board names as printable strings. Handy for
 *    referencing boards when printing trace and stuff.
 */
static char *stl_brdnames[] = {
      (char *) NULL,
      (char *) NULL,
      (char *) NULL,
      (char *) NULL,
      (char *) NULL,
      (char *) NULL,
      (char *) NULL,
      (char *) NULL,
      (char *) NULL,
      (char *) NULL,
      (char *) NULL,
      (char *) NULL,
      (char *) NULL,
      (char *) NULL,
      (char *) NULL,
      (char *) NULL,
      (char *) NULL,
      (char *) NULL,
      (char *) NULL,
      (char *) NULL,
      "EasyIO",
      "EC8/32-AT",
      "EC8/32-MC",
      (char *) NULL,
      (char *) NULL,
      (char *) NULL,
      "EC8/32-PCI",
      "EC8/64-PCI",
      "EasyIO-PCI",
};

/*****************************************************************************/

/*
 *    Define some string labels for arguments passed from the module
 *    load line. These allow for easy board definitions, and easy
 *    modification of the io, memory and irq resoucres.
 */
static int  stl_nargs = 0;
static char *board0[4];
static char *board1[4];
static char *board2[4];
static char *board3[4];

static char **stl_brdsp[] = {
      (char **) &board0,
      (char **) &board1,
      (char **) &board2,
      (char **) &board3
};

/*
 *    Define a set of common board names, and types. This is used to
 *    parse any module arguments.
 */

typedef struct stlbrdtype {
      char  *name;
      int   type;
} stlbrdtype_t;

static stlbrdtype_t     stl_brdstr[] = {
      { "easyio", BRD_EASYIO },
      { "eio", BRD_EASYIO },
      { "20", BRD_EASYIO },
      { "ec8/32", BRD_ECH },
      { "ec8/32-at", BRD_ECH },
      { "ec8/32-isa", BRD_ECH },
      { "ech", BRD_ECH },
      { "echat", BRD_ECH },
      { "21", BRD_ECH },
      { "ec8/32-mc", BRD_ECHMC },
      { "ec8/32-mca", BRD_ECHMC },
      { "echmc", BRD_ECHMC },
      { "echmca", BRD_ECHMC },
      { "22", BRD_ECHMC },
      { "ec8/32-pc", BRD_ECHPCI },
      { "ec8/32-pci", BRD_ECHPCI },
      { "26", BRD_ECHPCI },
      { "ec8/64-pc", BRD_ECH64PCI },
      { "ec8/64-pci", BRD_ECH64PCI },
      { "ech-pci", BRD_ECH64PCI },
      { "echpci", BRD_ECH64PCI },
      { "echpc", BRD_ECH64PCI },
      { "27", BRD_ECH64PCI },
      { "easyio-pc", BRD_EASYIOPCI },
      { "easyio-pci", BRD_EASYIOPCI },
      { "eio-pci", BRD_EASYIOPCI },
      { "eiopci", BRD_EASYIOPCI },
      { "28", BRD_EASYIOPCI },
};

/*
 *    Define the module agruments.
 */
MODULE_AUTHOR("Greg Ungerer");
MODULE_DESCRIPTION("Stallion Multiport Serial Driver");
MODULE_LICENSE("GPL");

module_param_array(board0, charp, &stl_nargs, 0);
MODULE_PARM_DESC(board0, "Board 0 config -> name[,ioaddr[,ioaddr2][,irq]]");
module_param_array(board1, charp, &stl_nargs, 0);
MODULE_PARM_DESC(board1, "Board 1 config -> name[,ioaddr[,ioaddr2][,irq]]");
module_param_array(board2, charp, &stl_nargs, 0);
MODULE_PARM_DESC(board2, "Board 2 config -> name[,ioaddr[,ioaddr2][,irq]]");
module_param_array(board3, charp, &stl_nargs, 0);
MODULE_PARM_DESC(board3, "Board 3 config -> name[,ioaddr[,ioaddr2][,irq]]");

/*****************************************************************************/

/*
 *    Hardware ID bits for the EasyIO and ECH boards. These defines apply
 *    to the directly accessible io ports of these boards (not the uarts -
 *    they are in cd1400.h and sc26198.h).
 */
#define     EIO_8PORTRS 0x04
#define     EIO_4PORTRS 0x05
#define     EIO_8PORTDI 0x00
#define     EIO_8PORTM  0x06
#define     EIO_MK3           0x03
#define     EIO_IDBITMASK     0x07

#define     EIO_BRDMASK 0xf0
#define     ID_BRD4           0x10
#define     ID_BRD8           0x20
#define     ID_BRD16    0x30

#define     EIO_INTRPEND      0x08
#define     EIO_INTEDGE 0x00
#define     EIO_INTLEVEL      0x08
#define     EIO_0WS           0x10

#define     ECH_ID            0xa0
#define     ECH_IDBITMASK     0xe0
#define     ECH_BRDENABLE     0x08
#define     ECH_BRDDISABLE    0x00
#define     ECH_INTENABLE     0x01
#define     ECH_INTDISABLE    0x00
#define     ECH_INTLEVEL      0x02
#define     ECH_INTEDGE 0x00
#define     ECH_INTRPEND      0x01
#define     ECH_BRDRESET      0x01

#define     ECHMC_INTENABLE   0x01
#define     ECHMC_BRDRESET    0x02

#define     ECH_PNLSTATUS     2
#define     ECH_PNL16PORT     0x20
#define     ECH_PNLIDMASK     0x07
#define     ECH_PNLXPID 0x40
#define     ECH_PNLINTRPEND   0x80

#define     ECH_ADDR2MASK     0x1e0

/*
 *    Define the vector mapping bits for the programmable interrupt board
 *    hardware. These bits encode the interrupt for the board to use - it
 *    is software selectable (except the EIO-8M).
 */
static unsigned char    stl_vecmap[] = {
      0xff, 0xff, 0xff, 0x04, 0x06, 0x05, 0xff, 0x07,
      0xff, 0xff, 0x00, 0x02, 0x01, 0xff, 0xff, 0x03
};

/*
 *    Lock ordering is that you may not take stallion_lock holding
 *    brd_lock.
 */

static spinlock_t brd_lock;         /* Guard the board mapping */
static spinlock_t stallion_lock;    /* Guard the tty driver */

/*
 *    Set up enable and disable macros for the ECH boards. They require
 *    the secondary io address space to be activated and deactivated.
 *    This way all ECH boards can share their secondary io region.
 *    If this is an ECH-PCI board then also need to set the page pointer
 *    to point to the correct page.
 */
#define     BRDENABLE(brdnr,pagenr)                               \
      if (stl_brds[(brdnr)]->brdtype == BRD_ECH)                  \
            outb((stl_brds[(brdnr)]->ioctrlval | ECH_BRDENABLE),  \
                  stl_brds[(brdnr)]->ioctrl);               \
      else if (stl_brds[(brdnr)]->brdtype == BRD_ECHPCI)          \
            outb((pagenr), stl_brds[(brdnr)]->ioctrl);

#define     BRDDISABLE(brdnr)                               \
      if (stl_brds[(brdnr)]->brdtype == BRD_ECH)                  \
            outb((stl_brds[(brdnr)]->ioctrlval | ECH_BRDDISABLE), \
                  stl_brds[(brdnr)]->ioctrl);

#define     STL_CD1400MAXBAUD 230400
#define     STL_SC26198MAXBAUD      460800

#define     STL_BAUDBASE            115200
#define     STL_CLOSEDELAY          (5 * HZ / 10)

/*****************************************************************************/

#ifdef CONFIG_PCI

/*
 *    Define the Stallion PCI vendor and device IDs.
 */
#ifndef     PCI_VENDOR_ID_STALLION
#define     PCI_VENDOR_ID_STALLION        0x124d
#endif
#ifndef PCI_DEVICE_ID_ECHPCI832
#define     PCI_DEVICE_ID_ECHPCI832       0x0000
#endif
#ifndef PCI_DEVICE_ID_ECHPCI864
#define     PCI_DEVICE_ID_ECHPCI864       0x0002
#endif
#ifndef PCI_DEVICE_ID_EIOPCI
#define     PCI_DEVICE_ID_EIOPCI          0x0003
#endif

/*
 *    Define structure to hold all Stallion PCI boards.
 */
typedef struct stlpcibrd {
      unsigned short          vendid;
      unsigned short          devid;
      int               brdtype;
} stlpcibrd_t;

static stlpcibrd_t      stl_pcibrds[] = {
      { PCI_VENDOR_ID_STALLION, PCI_DEVICE_ID_ECHPCI864, BRD_ECH64PCI },
      { PCI_VENDOR_ID_STALLION, PCI_DEVICE_ID_EIOPCI, BRD_EASYIOPCI },
      { PCI_VENDOR_ID_STALLION, PCI_DEVICE_ID_ECHPCI832, BRD_ECHPCI },
      { PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_87410, BRD_ECHPCI },
};

static int  stl_nrpcibrds = ARRAY_SIZE(stl_pcibrds);

#endif

/*****************************************************************************/

/*
 *    Define macros to extract a brd/port number from a minor number.
 */
#define     MINOR2BRD(min)          (((min) & 0xc0) >> 6)
#define     MINOR2PORT(min)         ((min) & 0x3f)

/*
 *    Define a baud rate table that converts termios baud rate selector
 *    into the actual baud rate value. All baud rate calculations are
 *    based on the actual baud rate required.
 */
static unsigned int     stl_baudrates[] = {
      0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
      9600, 19200, 38400, 57600, 115200, 230400, 460800, 921600
};

/*
 *    Define some handy local macros...
 */
#undef      MIN
#define     MIN(a,b)    (((a) <= (b)) ? (a) : (b))

#undef      TOLOWER
#define     TOLOWER(x)  ((((x) >= 'A') && ((x) <= 'Z')) ? ((x) + 0x20) : (x))

/*****************************************************************************/

/*
 *    Declare all those functions in this driver!
 */

static void stl_argbrds(void);
static int  stl_parsebrd(stlconf_t *confp, char **argp);

static unsigned long stl_atol(char *str);

static int  stl_init(void);
static int  stl_open(struct tty_struct *tty, struct file *filp);
static void stl_close(struct tty_struct *tty, struct file *filp);
static int  stl_write(struct tty_struct *tty, const unsigned char *buf, int count);
static void stl_putchar(struct tty_struct *tty, unsigned char ch);
static void stl_flushchars(struct tty_struct *tty);
static int  stl_writeroom(struct tty_struct *tty);
static int  stl_charsinbuffer(struct tty_struct *tty);
static int  stl_ioctl(struct tty_struct *tty, struct file *file, unsigned int cmd, unsigned long arg);
static void stl_settermios(struct tty_struct *tty, struct termios *old);
static void stl_throttle(struct tty_struct *tty);
static void stl_unthrottle(struct tty_struct *tty);
static void stl_stop(struct tty_struct *tty);
static void stl_start(struct tty_struct *tty);
static void stl_flushbuffer(struct tty_struct *tty);
static void stl_breakctl(struct tty_struct *tty, int state);
static void stl_waituntilsent(struct tty_struct *tty, int timeout);
static void stl_sendxchar(struct tty_struct *tty, char ch);
static void stl_hangup(struct tty_struct *tty);
static int  stl_memioctl(struct inode *ip, struct file *fp, unsigned int cmd, unsigned long arg);
static int  stl_portinfo(stlport_t *portp, int portnr, char *pos);
static int  stl_readproc(char *page, char **start, off_t off, int count, int *eof, void *data);

static int  stl_brdinit(stlbrd_t *brdp);
static int  stl_initports(stlbrd_t *brdp, stlpanel_t *panelp);
static int  stl_getserial(stlport_t *portp, struct serial_struct __user *sp);
static int  stl_setserial(stlport_t *portp, struct serial_struct __user *sp);
static int  stl_getbrdstats(combrd_t __user *bp);
static int  stl_getportstats(stlport_t *portp, comstats_t __user *cp);
static int  stl_clrportstats(stlport_t *portp, comstats_t __user *cp);
static int  stl_getportstruct(stlport_t __user *arg);
static int  stl_getbrdstruct(stlbrd_t __user *arg);
static int  stl_waitcarrier(stlport_t *portp, struct file *filp);
static int  stl_eiointr(stlbrd_t *brdp);
static int  stl_echatintr(stlbrd_t *brdp);
static int  stl_echmcaintr(stlbrd_t *brdp);
static int  stl_echpciintr(stlbrd_t *brdp);
static int  stl_echpci64intr(stlbrd_t *brdp);
static void stl_offintr(void *private);
static stlbrd_t *stl_allocbrd(void);
static stlport_t *stl_getport(int brdnr, int panelnr, int portnr);

static inline int stl_initbrds(void);
static inline int stl_initeio(stlbrd_t *brdp);
static inline int stl_initech(stlbrd_t *brdp);
static inline int stl_getbrdnr(void);

#ifdef      CONFIG_PCI
static inline int stl_findpcibrds(void);
static inline int stl_initpcibrd(int brdtype, struct pci_dev *devp);
#endif

/*
 *    CD1400 uart specific handling functions.
 */
static void stl_cd1400setreg(stlport_t *portp, int regnr, int value);
static int  stl_cd1400getreg(stlport_t *portp, int regnr);
static int  stl_cd1400updatereg(stlport_t *portp, int regnr, int value);
static int  stl_cd1400panelinit(stlbrd_t *brdp, stlpanel_t *panelp);
static void stl_cd1400portinit(stlbrd_t *brdp, stlpanel_t *panelp, stlport_t *portp);
static void stl_cd1400setport(stlport_t *portp, struct termios *tiosp);
static int  stl_cd1400getsignals(stlport_t *portp);
static void stl_cd1400setsignals(stlport_t *portp, int dtr, int rts);
static void stl_cd1400ccrwait(stlport_t *portp);
static void stl_cd1400enablerxtx(stlport_t *portp, int rx, int tx);
static void stl_cd1400startrxtx(stlport_t *portp, int rx, int tx);
static void stl_cd1400disableintrs(stlport_t *portp);
static void stl_cd1400sendbreak(stlport_t *portp, int len);
static void stl_cd1400flowctrl(stlport_t *portp, int state);
static void stl_cd1400sendflow(stlport_t *portp, int state);
static void stl_cd1400flush(stlport_t *portp);
static int  stl_cd1400datastate(stlport_t *portp);
static void stl_cd1400eiointr(stlpanel_t *panelp, unsigned int iobase);
static void stl_cd1400echintr(stlpanel_t *panelp, unsigned int iobase);
static void stl_cd1400txisr(stlpanel_t *panelp, int ioaddr);
static void stl_cd1400rxisr(stlpanel_t *panelp, int ioaddr);
static void stl_cd1400mdmisr(stlpanel_t *panelp, int ioaddr);

static inline int stl_cd1400breakisr(stlport_t *portp, int ioaddr);

/*
 *    SC26198 uart specific handling functions.
 */
static void stl_sc26198setreg(stlport_t *portp, int regnr, int value);
static int  stl_sc26198getreg(stlport_t *portp, int regnr);
static int  stl_sc26198updatereg(stlport_t *portp, int regnr, int value);
static int  stl_sc26198getglobreg(stlport_t *portp, int regnr);
static int  stl_sc26198panelinit(stlbrd_t *brdp, stlpanel_t *panelp);
static void stl_sc26198portinit(stlbrd_t *brdp, stlpanel_t *panelp, stlport_t *portp);
static void stl_sc26198setport(stlport_t *portp, struct termios *tiosp);
static int  stl_sc26198getsignals(stlport_t *portp);
static void stl_sc26198setsignals(stlport_t *portp, int dtr, int rts);
static void stl_sc26198enablerxtx(stlport_t *portp, int rx, int tx);
static void stl_sc26198startrxtx(stlport_t *portp, int rx, int tx);
static void stl_sc26198disableintrs(stlport_t *portp);
static void stl_sc26198sendbreak(stlport_t *portp, int len);
static void stl_sc26198flowctrl(stlport_t *portp, int state);
static void stl_sc26198sendflow(stlport_t *portp, int state);
static void stl_sc26198flush(stlport_t *portp);
static int  stl_sc26198datastate(stlport_t *portp);
static void stl_sc26198wait(stlport_t *portp);
static void stl_sc26198txunflow(stlport_t *portp, struct tty_struct *tty);
static void stl_sc26198intr(stlpanel_t *panelp, unsigned int iobase);
static void stl_sc26198txisr(stlport_t *port);
static void stl_sc26198rxisr(stlport_t *port, unsigned int iack);
static void stl_sc26198rxbadch(stlport_t *portp, unsigned char status, char ch);
static void stl_sc26198rxbadchars(stlport_t *portp);
static void stl_sc26198otherisr(stlport_t *port, unsigned int iack);

/*****************************************************************************/

/*
 *    Generic UART support structure.
 */
typedef struct uart {
      int   (*panelinit)(stlbrd_t *brdp, stlpanel_t *panelp);
      void  (*portinit)(stlbrd_t *brdp, stlpanel_t *panelp, stlport_t *portp);
      void  (*setport)(stlport_t *portp, struct termios *tiosp);
      int   (*getsignals)(stlport_t *portp);
      void  (*setsignals)(stlport_t *portp, int dtr, int rts);
      void  (*enablerxtx)(stlport_t *portp, int rx, int tx);
      void  (*startrxtx)(stlport_t *portp, int rx, int tx);
      void  (*disableintrs)(stlport_t *portp);
      void  (*sendbreak)(stlport_t *portp, int len);
      void  (*flowctrl)(stlport_t *portp, int state);
      void  (*sendflow)(stlport_t *portp, int state);
      void  (*flush)(stlport_t *portp);
      int   (*datastate)(stlport_t *portp);
      void  (*intr)(stlpanel_t *panelp, unsigned int iobase);
} uart_t;

/*
 *    Define some macros to make calling these functions nice and clean.
 */
#define     stl_panelinit           (* ((uart_t *) panelp->uartp)->panelinit)
#define     stl_portinit            (* ((uart_t *) portp->uartp)->portinit)
#define     stl_setport       (* ((uart_t *) portp->uartp)->setport)
#define     stl_getsignals          (* ((uart_t *) portp->uartp)->getsignals)
#define     stl_setsignals          (* ((uart_t *) portp->uartp)->setsignals)
#define     stl_enablerxtx          (* ((uart_t *) portp->uartp)->enablerxtx)
#define     stl_startrxtx           (* ((uart_t *) portp->uartp)->startrxtx)
#define     stl_disableintrs  (* ((uart_t *) portp->uartp)->disableintrs)
#define     stl_sendbreak           (* ((uart_t *) portp->uartp)->sendbreak)
#define     stl_flowctrl            (* ((uart_t *) portp->uartp)->flowctrl)
#define     stl_sendflow            (* ((uart_t *) portp->uartp)->sendflow)
#define     stl_flush         (* ((uart_t *) portp->uartp)->flush)
#define     stl_datastate           (* ((uart_t *) portp->uartp)->datastate)

/*****************************************************************************/

/*
 *    CD1400 UART specific data initialization.
 */
static uart_t stl_cd1400uart = {
      stl_cd1400panelinit,
      stl_cd1400portinit,
      stl_cd1400setport,
      stl_cd1400getsignals,
      stl_cd1400setsignals,
      stl_cd1400enablerxtx,
      stl_cd1400startrxtx,
      stl_cd1400disableintrs,
      stl_cd1400sendbreak,
      stl_cd1400flowctrl,
      stl_cd1400sendflow,
      stl_cd1400flush,
      stl_cd1400datastate,
      stl_cd1400eiointr
};

/*
 *    Define the offsets within the register bank of a cd1400 based panel.
 *    These io address offsets are common to the EasyIO board as well.
 */
#define     EREG_ADDR   0
#define     EREG_DATA   4
#define     EREG_RXACK  5
#define     EREG_TXACK  6
#define     EREG_MDACK  7

#define     EREG_BANKSIZE     8

#define     CD1400_CLK  25000000
#define     CD1400_CLK8M      20000000

/*
 *    Define the cd1400 baud rate clocks. These are used when calculating
 *    what clock and divisor to use for the required baud rate. Also
 *    define the maximum baud rate allowed, and the default base baud.
 */
static int  stl_cd1400clkdivs[] = {
      CD1400_CLK0, CD1400_CLK1, CD1400_CLK2, CD1400_CLK3, CD1400_CLK4
};

/*****************************************************************************/

/*
 *    SC26198 UART specific data initization.
 */
static uart_t stl_sc26198uart = {
      stl_sc26198panelinit,
      stl_sc26198portinit,
      stl_sc26198setport,
      stl_sc26198getsignals,
      stl_sc26198setsignals,
      stl_sc26198enablerxtx,
      stl_sc26198startrxtx,
      stl_sc26198disableintrs,
      stl_sc26198sendbreak,
      stl_sc26198flowctrl,
      stl_sc26198sendflow,
      stl_sc26198flush,
      stl_sc26198datastate,
      stl_sc26198intr
};

/*
 *    Define the offsets within the register bank of a sc26198 based panel.
 */
#define     XP_DATA           0
#define     XP_ADDR           1
#define     XP_MODID    2
#define     XP_STATUS   2
#define     XP_IACK           3

#define     XP_BANKSIZE 4

/*
 *    Define the sc26198 baud rate table. Offsets within the table
 *    represent the actual baud rate selector of sc26198 registers.
 */
static unsigned int     sc26198_baudtable[] = {
      50, 75, 150, 200, 300, 450, 600, 900, 1200, 1800, 2400, 3600,
      4800, 7200, 9600, 14400, 19200, 28800, 38400, 57600, 115200,
      230400, 460800, 921600
};

#define     SC26198_NRBAUDS         ARRAY_SIZE(sc26198_baudtable)

/*****************************************************************************/

/*
 *    Define the driver info for a user level control device. Used mainly
 *    to get at port stats - only not using the port device itself.
 */
static const struct file_operations stl_fsiomem = {
      .owner            = THIS_MODULE,
      .ioctl            = stl_memioctl,
};

/*****************************************************************************/

static struct class *stallion_class;

/*
 *    Loadable module initialization stuff.
 */

static int __init stallion_module_init(void)
{
      stl_init();
      return 0;
}

/*****************************************************************************/

static void __exit stallion_module_exit(void)
{
      stlbrd_t    *brdp;
      stlpanel_t  *panelp;
      stlport_t   *portp;
      int         i, j, k;

#ifdef DEBUG
      printk("cleanup_module()\n");
#endif

      printk(KERN_INFO "Unloading %s: version %s\n", stl_drvtitle,
            stl_drvversion);

/*
 *    Free up all allocated resources used by the ports. This includes
 *    memory and interrupts. As part of this process we will also do
 *    a hangup on every open port - to try to flush out any processes
 *    hanging onto ports.
 */
      i = tty_unregister_driver(stl_serial);
      put_tty_driver(stl_serial);
      if (i) {
            printk("STALLION: failed to un-register tty driver, "
                  "errno=%d\n", -i);
            return;
      }
      for (i = 0; i < 4; i++)
            class_device_destroy(stallion_class, MKDEV(STL_SIOMEMMAJOR, i));
      if ((i = unregister_chrdev(STL_SIOMEMMAJOR, "staliomem")))
            printk("STALLION: failed to un-register serial memory device, "
                  "errno=%d\n", -i);
      class_destroy(stallion_class);

      for (i = 0; (i < stl_nrbrds); i++) {
            if ((brdp = stl_brds[i]) == (stlbrd_t *) NULL)
                  continue;

            free_irq(brdp->irq, brdp);

            for (j = 0; (j < STL_MAXPANELS); j++) {
                  panelp = brdp->panels[j];
                  if (panelp == (stlpanel_t *) NULL)
                        continue;
                  for (k = 0; (k < STL_PORTSPERPANEL); k++) {
                        portp = panelp->ports[k];
                        if (portp == (stlport_t *) NULL)
                              continue;
                        if (portp->tty != (struct tty_struct *) NULL)
                              stl_hangup(portp->tty);
                        kfree(portp->tx.buf);
                        kfree(portp);
                  }
                  kfree(panelp);
            }

            release_region(brdp->ioaddr1, brdp->iosize1);
            if (brdp->iosize2 > 0)
                  release_region(brdp->ioaddr2, brdp->iosize2);

            kfree(brdp);
            stl_brds[i] = (stlbrd_t *) NULL;
      }
}

module_init(stallion_module_init);
module_exit(stallion_module_exit);

/*****************************************************************************/

/*
 *    Check for any arguments passed in on the module load command line.
 */

static void stl_argbrds(void)
{
      stlconf_t   conf;
      stlbrd_t    *brdp;
      int         i;

#ifdef DEBUG
      printk("stl_argbrds()\n");
#endif

      for (i = stl_nrbrds; (i < stl_nargs); i++) {
            memset(&conf, 0, sizeof(conf));
            if (stl_parsebrd(&conf, stl_brdsp[i]) == 0)
                  continue;
            if ((brdp = stl_allocbrd()) == (stlbrd_t *) NULL)
                  continue;
            stl_nrbrds = i + 1;
            brdp->brdnr = i;
            brdp->brdtype = conf.brdtype;
            brdp->ioaddr1 = conf.ioaddr1;
            brdp->ioaddr2 = conf.ioaddr2;
            brdp->irq = conf.irq;
            brdp->irqtype = conf.irqtype;
            stl_brdinit(brdp);
      }
}

/*****************************************************************************/

/*
 *    Convert an ascii string number into an unsigned long.
 */

static unsigned long stl_atol(char *str)
{
      unsigned long     val;
      int         base, c;
      char        *sp;

      val = 0;
      sp = str;
      if ((*sp == '0') && (*(sp+1) == 'x')) {
            base = 16;
            sp += 2;
      } else if (*sp == '0') {
            base = 8;
            sp++;
      } else {
            base = 10;
      }

      for (; (*sp != 0); sp++) {
            c = (*sp > '9') ? (TOLOWER(*sp) - 'a' + 10) : (*sp - '0');
            if ((c < 0) || (c >= base)) {
                  printk("STALLION: invalid argument %s\n", str);
                  val = 0;
                  break;
            }
            val = (val * base) + c;
      }
      return val;
}

/*****************************************************************************/

/*
 *    Parse the supplied argument string, into the board conf struct.
 */

static int stl_parsebrd(stlconf_t *confp, char **argp)
{
      char  *sp;
      int   i;

#ifdef DEBUG
      printk("stl_parsebrd(confp=%x,argp=%x)\n", (int) confp, (int) argp);
#endif

      if ((argp[0] == (char *) NULL) || (*argp[0] == 0))
            return 0;

      for (sp = argp[0], i = 0; ((*sp != 0) && (i < 25)); sp++, i++)
            *sp = TOLOWER(*sp);

      for (i = 0; i < ARRAY_SIZE(stl_brdstr); i++) {
            if (strcmp(stl_brdstr[i].name, argp[0]) == 0)
                  break;
      }
      if (i == ARRAY_SIZE(stl_brdstr)) {
            printk("STALLION: unknown board name, %s?\n", argp[0]);
            return 0;
      }

      confp->brdtype = stl_brdstr[i].type;

      i = 1;
      if ((argp[i] != (char *) NULL) && (*argp[i] != 0))
            confp->ioaddr1 = stl_atol(argp[i]);
      i++;
      if (confp->brdtype == BRD_ECH) {
            if ((argp[i] != (char *) NULL) && (*argp[i] != 0))
                  confp->ioaddr2 = stl_atol(argp[i]);
            i++;
      }
      if ((argp[i] != (char *) NULL) && (*argp[i] != 0))
            confp->irq = stl_atol(argp[i]);
      return 1;
}

/*****************************************************************************/

/*
 *    Allocate a new board structure. Fill out the basic info in it.
 */

static stlbrd_t *stl_allocbrd(void)
{
      stlbrd_t    *brdp;

      brdp = kzalloc(sizeof(stlbrd_t), GFP_KERNEL);
      if (!brdp) {
            printk("STALLION: failed to allocate memory (size=%Zd)\n",
                  sizeof(stlbrd_t));
            return NULL;
      }

      brdp->magic = STL_BOARDMAGIC;
      return brdp;
}

/*****************************************************************************/

static int stl_open(struct tty_struct *tty, struct file *filp)
{
      stlport_t   *portp;
      stlbrd_t    *brdp;
      unsigned int      minordev;
      int         brdnr, panelnr, portnr, rc;

#ifdef DEBUG
      printk("stl_open(tty=%x,filp=%x): device=%s\n", (int) tty,
            (int) filp, tty->name);
#endif

      minordev = tty->index;
      brdnr = MINOR2BRD(minordev);
      if (brdnr >= stl_nrbrds)
            return -ENODEV;
      brdp = stl_brds[brdnr];
      if (brdp == (stlbrd_t *) NULL)
            return -ENODEV;
      minordev = MINOR2PORT(minordev);
      for (portnr = -1, panelnr = 0; (panelnr < STL_MAXPANELS); panelnr++) {
            if (brdp->panels[panelnr] == (stlpanel_t *) NULL)
                  break;
            if (minordev < brdp->panels[panelnr]->nrports) {
                  portnr = minordev;
                  break;
            }
            minordev -= brdp->panels[panelnr]->nrports;
      }
      if (portnr < 0)
            return -ENODEV;

      portp = brdp->panels[panelnr]->ports[portnr];
      if (portp == (stlport_t *) NULL)
            return -ENODEV;

/*
 *    On the first open of the device setup the port hardware, and
 *    initialize the per port data structure.
 */
      portp->tty = tty;
      tty->driver_data = portp;
      portp->refcount++;

      if ((portp->flags & ASYNC_INITIALIZED) == 0) {
            if (!portp->tx.buf) {
                  portp->tx.buf = kmalloc(STL_TXBUFSIZE, GFP_KERNEL);
                  if (!portp->tx.buf)
                        return -ENOMEM;
                  portp->tx.head = portp->tx.buf;
                  portp->tx.tail = portp->tx.buf;
            }
            stl_setport(portp, tty->termios);
            portp->sigs = stl_getsignals(portp);
            stl_setsignals(portp, 1, 1);
            stl_enablerxtx(portp, 1, 1);
            stl_startrxtx(portp, 1, 0);
            clear_bit(TTY_IO_ERROR, &tty->flags);
            portp->flags |= ASYNC_INITIALIZED;
      }

/*
 *    Check if this port is in the middle of closing. If so then wait
 *    until it is closed then return error status, based on flag settings.
 *    The sleep here does not need interrupt protection since the wakeup
 *    for it is done with the same context.
 */
      if (portp->flags & ASYNC_CLOSING) {
            interruptible_sleep_on(&portp->close_wait);
            if (portp->flags & ASYNC_HUP_NOTIFY)
                  return -EAGAIN;
            return -ERESTARTSYS;
      }

/*
 *    Based on type of open being done check if it can overlap with any
 *    previous opens still in effect. If we are a normal serial device
 *    then also we might have to wait for carrier.
 */
      if (!(filp->f_flags & O_NONBLOCK)) {
            if ((rc = stl_waitcarrier(portp, filp)) != 0)
                  return rc;
      }
      portp->flags |= ASYNC_NORMAL_ACTIVE;

      return 0;
}

/*****************************************************************************/

/*
 *    Possibly need to wait for carrier (DCD signal) to come high. Say
 *    maybe because if we are clocal then we don't need to wait...
 */

static int stl_waitcarrier(stlport_t *portp, struct file *filp)
{
      unsigned long     flags;
      int         rc, doclocal;

#ifdef DEBUG
      printk("stl_waitcarrier(portp=%x,filp=%x)\n", (int) portp, (int) filp);
#endif

      rc = 0;
      doclocal = 0;

      spin_lock_irqsave(&stallion_lock, flags);

      if (portp->tty->termios->c_cflag & CLOCAL)
            doclocal++;

      portp->openwaitcnt++;
      if (! tty_hung_up_p(filp))
            portp->refcount--;

      for (;;) {
            /* Takes brd_lock internally */
            stl_setsignals(portp, 1, 1);
            if (tty_hung_up_p(filp) ||
                ((portp->flags & ASYNC_INITIALIZED) == 0)) {
                  if (portp->flags & ASYNC_HUP_NOTIFY)
                        rc = -EBUSY;
                  else
                        rc = -ERESTARTSYS;
                  break;
            }
            if (((portp->flags & ASYNC_CLOSING) == 0) &&
                (doclocal || (portp->sigs & TIOCM_CD))) {
                  break;
            }
            if (signal_pending(current)) {
                  rc = -ERESTARTSYS;
                  break;
            }
            /* FIXME */
            interruptible_sleep_on(&portp->open_wait);
      }

      if (! tty_hung_up_p(filp))
            portp->refcount++;
      portp->openwaitcnt--;
      spin_unlock_irqrestore(&stallion_lock, flags);

      return rc;
}

/*****************************************************************************/

static void stl_close(struct tty_struct *tty, struct file *filp)
{
      stlport_t   *portp;
      unsigned long     flags;

#ifdef DEBUG
      printk("stl_close(tty=%x,filp=%x)\n", (int) tty, (int) filp);
#endif

      portp = tty->driver_data;
      if (portp == (stlport_t *) NULL)
            return;

      spin_lock_irqsave(&stallion_lock, flags);
      if (tty_hung_up_p(filp)) {
            spin_unlock_irqrestore(&stallion_lock, flags);
            return;
      }
      if ((tty->count == 1) && (portp->refcount != 1))
            portp->refcount = 1;
      if (portp->refcount-- > 1) {
            spin_unlock_irqrestore(&stallion_lock, flags);
            return;
      }

      portp->refcount = 0;
      portp->flags |= ASYNC_CLOSING;

/*
 *    May want to wait for any data to drain before closing. The BUSY
 *    flag keeps track of whether we are still sending or not - it is
 *    very accurate for the cd1400, not quite so for the sc26198.
 *    (The sc26198 has no "end-of-data" interrupt only empty FIFO)
 */
      tty->closing = 1;

      spin_unlock_irqrestore(&stallion_lock, flags);

      if (portp->closing_wait != ASYNC_CLOSING_WAIT_NONE)
            tty_wait_until_sent(tty, portp->closing_wait);
      stl_waituntilsent(tty, (HZ / 2));


      spin_lock_irqsave(&stallion_lock, flags);
      portp->flags &= ~ASYNC_INITIALIZED;
      spin_unlock_irqrestore(&stallion_lock, flags);

      stl_disableintrs(portp);
      if (tty->termios->c_cflag & HUPCL)
            stl_setsignals(portp, 0, 0);
      stl_enablerxtx(portp, 0, 0);
      stl_flushbuffer(tty);
      portp->istate = 0;
      if (portp->tx.buf != (char *) NULL) {
            kfree(portp->tx.buf);
            portp->tx.buf = (char *) NULL;
            portp->tx.head = (char *) NULL;
            portp->tx.tail = (char *) NULL;
      }
      set_bit(TTY_IO_ERROR, &tty->flags);
      tty_ldisc_flush(tty);

      tty->closing = 0;
      portp->tty = (struct tty_struct *) NULL;

      if (portp->openwaitcnt) {
            if (portp->close_delay)
                  msleep_interruptible(jiffies_to_msecs(portp->close_delay));
            wake_up_interruptible(&portp->open_wait);
      }

      portp->flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING);
      wake_up_interruptible(&portp->close_wait);
}

/*****************************************************************************/

/*
 *    Write routine. Take data and stuff it in to the TX ring queue.
 *    If transmit interrupts are not running then start them.
 */

static int stl_write(struct tty_struct *tty, const unsigned char *buf, int count)
{
      stlport_t   *portp;
      unsigned int      len, stlen;
      unsigned char     *chbuf;
      char        *head, *tail;

#ifdef DEBUG
      printk("stl_write(tty=%x,buf=%x,count=%d)\n",
            (int) tty, (int) buf, count);
#endif

      portp = tty->driver_data;
      if (portp == (stlport_t *) NULL)
            return 0;
      if (portp->tx.buf == (char *) NULL)
            return 0;

/*
 *    If copying direct from user space we must cater for page faults,
 *    causing us to "sleep" here for a while. To handle this copy in all
 *    the data we need now, into a local buffer. Then when we got it all
 *    copy it into the TX buffer.
 */
      chbuf = (unsigned char *) buf;

      head = portp->tx.head;
      tail = portp->tx.tail;
      if (head >= tail) {
            len = STL_TXBUFSIZE - (head - tail) - 1;
            stlen = STL_TXBUFSIZE - (head - portp->tx.buf);
      } else {
            len = tail - head - 1;
            stlen = len;
      }

      len = MIN(len, count);
      count = 0;
      while (len > 0) {
            stlen = MIN(len, stlen);
            memcpy(head, chbuf, stlen);
            len -= stlen;
            chbuf += stlen;
            count += stlen;
            head += stlen;
            if (head >= (portp->tx.buf + STL_TXBUFSIZE)) {
                  head = portp->tx.buf;
                  stlen = tail - head;
            }
      }
      portp->tx.head = head;

      clear_bit(ASYI_TXLOW, &portp->istate);
      stl_startrxtx(portp, -1, 1);

      return count;
}

/*****************************************************************************/

static void stl_putchar(struct tty_struct *tty, unsigned char ch)
{
      stlport_t   *portp;
      unsigned int      len;
      char        *head, *tail;

#ifdef DEBUG
      printk("stl_putchar(tty=%x,ch=%x)\n", (int) tty, (int) ch);
#endif

      if (tty == (struct tty_struct *) NULL)
            return;
      portp = tty->driver_data;
      if (portp == (stlport_t *) NULL)
            return;
      if (portp->tx.buf == (char *) NULL)
            return;

      head = portp->tx.head;
      tail = portp->tx.tail;

      len = (head >= tail) ? (STL_TXBUFSIZE - (head - tail)) : (tail - head);
      len--;

      if (len > 0) {
            *head++ = ch;
            if (head >= (portp->tx.buf + STL_TXBUFSIZE))
                  head = portp->tx.buf;
      }     
      portp->tx.head = head;
}

/*****************************************************************************/

/*
 *    If there are any characters in the buffer then make sure that TX
 *    interrupts are on and get'em out. Normally used after the putchar
 *    routine has been called.
 */

static void stl_flushchars(struct tty_struct *tty)
{
      stlport_t   *portp;

#ifdef DEBUG
      printk("stl_flushchars(tty=%x)\n", (int) tty);
#endif

      if (tty == (struct tty_struct *) NULL)
            return;
      portp = tty->driver_data;
      if (portp == (stlport_t *) NULL)
            return;
      if (portp->tx.buf == (char *) NULL)
            return;

      stl_startrxtx(portp, -1, 1);
}

/*****************************************************************************/

static int stl_writeroom(struct tty_struct *tty)
{
      stlport_t   *portp;
      char        *head, *tail;

#ifdef DEBUG
      printk("stl_writeroom(tty=%x)\n", (int) tty);
#endif

      if (tty == (struct tty_struct *) NULL)
            return 0;
      portp = tty->driver_data;
      if (portp == (stlport_t *) NULL)
            return 0;
      if (portp->tx.buf == (char *) NULL)
            return 0;

      head = portp->tx.head;
      tail = portp->tx.tail;
      return ((head >= tail) ? (STL_TXBUFSIZE - (head - tail) - 1) : (tail - head - 1));
}

/*****************************************************************************/

/*
 *    Return number of chars in the TX buffer. Normally we would just
 *    calculate the number of chars in the buffer and return that, but if
 *    the buffer is empty and TX interrupts are still on then we return
 *    that the buffer still has 1 char in it. This way whoever called us
 *    will not think that ALL chars have drained - since the UART still
 *    must have some chars in it (we are busy after all).
 */

static int stl_charsinbuffer(struct tty_struct *tty)
{
      stlport_t   *portp;
      unsigned int      size;
      char        *head, *tail;

#ifdef DEBUG
      printk("stl_charsinbuffer(tty=%x)\n", (int) tty);
#endif

      if (tty == (struct tty_struct *) NULL)
            return 0;
      portp = tty->driver_data;
      if (portp == (stlport_t *) NULL)
            return 0;
      if (portp->tx.buf == (char *) NULL)
            return 0;

      head = portp->tx.head;
      tail = portp->tx.tail;
      size = (head >= tail) ? (head - tail) : (STL_TXBUFSIZE - (tail - head));
      if ((size == 0) && test_bit(ASYI_TXBUSY, &portp->istate))
            size = 1;
      return size;
}

/*****************************************************************************/

/*
 *    Generate the serial struct info.
 */

static int stl_getserial(stlport_t *portp, struct serial_struct __user *sp)
{
      struct serial_struct    sio;
      stlbrd_t          *brdp;

#ifdef DEBUG
      printk("stl_getserial(portp=%x,sp=%x)\n", (int) portp, (int) sp);
#endif

      memset(&sio, 0, sizeof(struct serial_struct));
      sio.line = portp->portnr;
      sio.port = portp->ioaddr;
      sio.flags = portp->flags;
      sio.baud_base = portp->baud_base;
      sio.close_delay = portp->close_delay;
      sio.closing_wait = portp->closing_wait;
      sio.custom_divisor = portp->custom_divisor;
      sio.hub6 = 0;
      if (portp->uartp == &stl_cd1400uart) {
            sio.type = PORT_CIRRUS;
            sio.xmit_fifo_size = CD1400_TXFIFOSIZE;
      } else {
            sio.type = PORT_UNKNOWN;
            sio.xmit_fifo_size = SC26198_TXFIFOSIZE;
      }

      brdp = stl_brds[portp->brdnr];
      if (brdp != (stlbrd_t *) NULL)
            sio.irq = brdp->irq;

      return copy_to_user(sp, &sio, sizeof(struct serial_struct)) ? -EFAULT : 0;
}

/*****************************************************************************/

/*
 *    Set port according to the serial struct info.
 *    At this point we do not do any auto-configure stuff, so we will
 *    just quietly ignore any requests to change irq, etc.
 */

static int stl_setserial(stlport_t *portp, struct serial_struct __user *sp)
{
      struct serial_struct    sio;

#ifdef DEBUG
      printk("stl_setserial(portp=%x,sp=%x)\n", (int) portp, (int) sp);
#endif

      if (copy_from_user(&sio, sp, sizeof(struct serial_struct)))
            return -EFAULT;
      if (!capable(CAP_SYS_ADMIN)) {
            if ((sio.baud_base != portp->baud_base) ||
                (sio.close_delay != portp->close_delay) ||
                ((sio.flags & ~ASYNC_USR_MASK) !=
                (portp->flags & ~ASYNC_USR_MASK)))
                  return -EPERM;
      } 

      portp->flags = (portp->flags & ~ASYNC_USR_MASK) |
            (sio.flags & ASYNC_USR_MASK);
      portp->baud_base = sio.baud_base;
      portp->close_delay = sio.close_delay;
      portp->closing_wait = sio.closing_wait;
      portp->custom_divisor = sio.custom_divisor;
      stl_setport(portp, portp->tty->termios);
      return 0;
}

/*****************************************************************************/

static int stl_tiocmget(struct tty_struct *tty, struct file *file)
{
      stlport_t   *portp;

      if (tty == (struct tty_struct *) NULL)
            return -ENODEV;
      portp = tty->driver_data;
      if (portp == (stlport_t *) NULL)
            return -ENODEV;
      if (tty->flags & (1 << TTY_IO_ERROR))
            return -EIO;

      return stl_getsignals(portp);
}

static int stl_tiocmset(struct tty_struct *tty, struct file *file,
                  unsigned int set, unsigned int clear)
{
      stlport_t   *portp;
      int rts = -1, dtr = -1;

      if (tty == (struct tty_struct *) NULL)
            return -ENODEV;
      portp = tty->driver_data;
      if (portp == (stlport_t *) NULL)
            return -ENODEV;
      if (tty->flags & (1 << TTY_IO_ERROR))
            return -EIO;

      if (set & TIOCM_RTS)
            rts = 1;
      if (set & TIOCM_DTR)
            dtr = 1;
      if (clear & TIOCM_RTS)
            rts = 0;
      if (clear & TIOCM_DTR)
            dtr = 0;

      stl_setsignals(portp, dtr, rts);
      return 0;
}

static int stl_ioctl(struct tty_struct *tty, struct file *file, unsigned int cmd, unsigned long arg)
{
      stlport_t   *portp;
      unsigned int      ival;
      int         rc;
      void __user *argp = (void __user *)arg;

#ifdef DEBUG
      printk("stl_ioctl(tty=%x,file=%x,cmd=%x,arg=%x)\n",
            (int) tty, (int) file, cmd, (int) arg);
#endif

      if (tty == (struct tty_struct *) NULL)
            return -ENODEV;
      portp = tty->driver_data;
      if (portp == (stlport_t *) NULL)
            return -ENODEV;

      if ((cmd != TIOCGSERIAL) && (cmd != TIOCSSERIAL) &&
          (cmd != COM_GETPORTSTATS) && (cmd != COM_CLRPORTSTATS)) {
            if (tty->flags & (1 << TTY_IO_ERROR))
                  return -EIO;
      }

      rc = 0;

      switch (cmd) {
      case TIOCGSOFTCAR:
            rc = put_user(((tty->termios->c_cflag & CLOCAL) ? 1 : 0),
                  (unsigned __user *) argp);
            break;
      case TIOCSSOFTCAR:
            if (get_user(ival, (unsigned int __user *) arg))
                  return -EFAULT;
            tty->termios->c_cflag =
                        (tty->termios->c_cflag & ~CLOCAL) |
                        (ival ? CLOCAL : 0);
            break;
      case TIOCGSERIAL:
            rc = stl_getserial(portp, argp);
            break;
      case TIOCSSERIAL:
            rc = stl_setserial(portp, argp);
            break;
      case COM_GETPORTSTATS:
            rc = stl_getportstats(portp, argp);
            break;
      case COM_CLRPORTSTATS:
            rc = stl_clrportstats(portp, argp);
            break;
      case TIOCSERCONFIG:
      case TIOCSERGWILD:
      case TIOCSERSWILD:
      case TIOCSERGETLSR:
      case TIOCSERGSTRUCT:
      case TIOCSERGETMULTI:
      case TIOCSERSETMULTI:
      default:
            rc = -ENOIOCTLCMD;
            break;
      }

      return rc;
}

/*****************************************************************************/

static void stl_settermios(struct tty_struct *tty, struct termios *old)
{
      stlport_t   *portp;
      struct termios    *tiosp;

#ifdef DEBUG
      printk("stl_settermios(tty=%x,old=%x)\n", (int) tty, (int) old);
#endif

      if (tty == (struct tty_struct *) NULL)
            return;
      portp = tty->driver_data;
      if (portp == (stlport_t *) NULL)
            return;

      tiosp = tty->termios;
      if ((tiosp->c_cflag == old->c_cflag) &&
          (tiosp->c_iflag == old->c_iflag))
            return;

      stl_setport(portp, tiosp);
      stl_setsignals(portp, ((tiosp->c_cflag & (CBAUD & ~CBAUDEX)) ? 1 : 0),
            -1);
      if ((old->c_cflag & CRTSCTS) && ((tiosp->c_cflag & CRTSCTS) == 0)) {
            tty->hw_stopped = 0;
            stl_start(tty);
      }
      if (((old->c_cflag & CLOCAL) == 0) && (tiosp->c_cflag & CLOCAL))
            wake_up_interruptible(&portp->open_wait);
}

/*****************************************************************************/

/*
 *    Attempt to flow control who ever is sending us data. Based on termios
 *    settings use software or/and hardware flow control.
 */

static void stl_throttle(struct tty_struct *tty)
{
      stlport_t   *portp;

#ifdef DEBUG
      printk("stl_throttle(tty=%x)\n", (int) tty);
#endif

      if (tty == (struct tty_struct *) NULL)
            return;
      portp = tty->driver_data;
      if (portp == (stlport_t *) NULL)
            return;
      stl_flowctrl(portp, 0);
}

/*****************************************************************************/

/*
 *    Unflow control the device sending us data...
 */

static void stl_unthrottle(struct tty_struct *tty)
{
      stlport_t   *portp;

#ifdef DEBUG
      printk("stl_unthrottle(tty=%x)\n", (int) tty);
#endif

      if (tty == (struct tty_struct *) NULL)
            return;
      portp = tty->driver_data;
      if (portp == (stlport_t *) NULL)
            return;
      stl_flowctrl(portp, 1);
}

/*****************************************************************************/

/*
 *    Stop the transmitter. Basically to do this we will just turn TX
 *    interrupts off.
 */

static void stl_stop(struct tty_struct *tty)
{
      stlport_t   *portp;

#ifdef DEBUG
      printk("stl_stop(tty=%x)\n", (int) tty);
#endif

      if (tty == (struct tty_struct *) NULL)
            return;
      portp = tty->driver_data;
      if (portp == (stlport_t *) NULL)
            return;
      stl_startrxtx(portp, -1, 0);
}

/*****************************************************************************/

/*
 *    Start the transmitter again. Just turn TX interrupts back on.
 */

static void stl_start(struct tty_struct *tty)
{
      stlport_t   *portp;

#ifdef DEBUG
      printk("stl_start(tty=%x)\n", (int) tty);
#endif

      if (tty == (struct tty_struct *) NULL)
            return;
      portp = tty->driver_data;
      if (portp == (stlport_t *) NULL)
            return;
      stl_startrxtx(portp, -1, 1);
}

/*****************************************************************************/

/*
 *    Hangup this port. This is pretty much like closing the port, only
 *    a little more brutal. No waiting for data to drain. Shutdown the
 *    port and maybe drop signals.
 */

static void stl_hangup(struct tty_struct *tty)
{
      stlport_t   *portp;

#ifdef DEBUG
      printk("stl_hangup(tty=%x)\n", (int) tty);
#endif

      if (tty == (struct tty_struct *) NULL)
            return;
      portp = tty->driver_data;
      if (portp == (stlport_t *) NULL)
            return;

      portp->flags &= ~ASYNC_INITIALIZED;
      stl_disableintrs(portp);
      if (tty->termios->c_cflag & HUPCL)
            stl_setsignals(portp, 0, 0);
      stl_enablerxtx(portp, 0, 0);
      stl_flushbuffer(tty);
      portp->istate = 0;
      set_bit(TTY_IO_ERROR, &tty->flags);
      if (portp->tx.buf != (char *) NULL) {
            kfree(portp->tx.buf);
            portp->tx.buf = (char *) NULL;
            portp->tx.head = (char *) NULL;
            portp->tx.tail = (char *) NULL;
      }
      portp->tty = (struct tty_struct *) NULL;
      portp->flags &= ~ASYNC_NORMAL_ACTIVE;
      portp->refcount = 0;
      wake_up_interruptible(&portp->open_wait);
}

/*****************************************************************************/

static void stl_flushbuffer(struct tty_struct *tty)
{
      stlport_t   *portp;

#ifdef DEBUG
      printk("stl_flushbuffer(tty=%x)\n", (int) tty);
#endif

      if (tty == (struct tty_struct *) NULL)
            return;
      portp = tty->driver_data;
      if (portp == (stlport_t *) NULL)
            return;

      stl_flush(portp);
      tty_wakeup(tty);
}

/*****************************************************************************/

static void stl_breakctl(struct tty_struct *tty, int state)
{
      stlport_t   *portp;

#ifdef DEBUG
      printk("stl_breakctl(tty=%x,state=%d)\n", (int) tty, state);
#endif

      if (tty == (struct tty_struct *) NULL)
            return;
      portp = tty->driver_data;
      if (portp == (stlport_t *) NULL)
            return;

      stl_sendbreak(portp, ((state == -1) ? 1 : 2));
}

/*****************************************************************************/

static void stl_waituntilsent(struct tty_struct *tty, int timeout)
{
      stlport_t   *portp;
      unsigned long     tend;

#ifdef DEBUG
      printk("stl_waituntilsent(tty=%x,timeout=%d)\n", (int) tty, timeout);
#endif

      if (tty == (struct tty_struct *) NULL)
            return;
      portp = tty->driver_data;
      if (portp == (stlport_t *) NULL)
            return;

      if (timeout == 0)
            timeout = HZ;
      tend = jiffies + timeout;

      while (stl_datastate(portp)) {
            if (signal_pending(current))
                  break;
            msleep_interruptible(20);
            if (time_after_eq(jiffies, tend))
                  break;
      }
}

/*****************************************************************************/

static void stl_sendxchar(struct tty_struct *tty, char ch)
{
      stlport_t   *portp;

#ifdef DEBUG
      printk("stl_sendxchar(tty=%x,ch=%x)\n", (int) tty, ch);
#endif

      if (tty == (struct tty_struct *) NULL)
            return;
      portp = tty->driver_data;
      if (portp == (stlport_t *) NULL)
            return;

      if (ch == STOP_CHAR(tty))
            stl_sendflow(portp, 0);
      else if (ch == START_CHAR(tty))
            stl_sendflow(portp, 1);
      else
            stl_putchar(tty, ch);
}

/*****************************************************************************/

#define     MAXLINE           80

/*
 *    Format info for a specified port. The line is deliberately limited
 *    to 80 characters. (If it is too long it will be truncated, if too
 *    short then padded with spaces).
 */

static int stl_portinfo(stlport_t *portp, int portnr, char *pos)
{
      char  *sp;
      int   sigs, cnt;

      sp = pos;
      sp += sprintf(sp, "%d: uart:%s tx:%d rx:%d",
            portnr, (portp->hwid == 1) ? "SC26198" : "CD1400",
            (int) portp->stats.txtotal, (int) portp->stats.rxtotal);

      if (portp->stats.rxframing)
            sp += sprintf(sp, " fe:%d", (int) portp->stats.rxframing);
      if (portp->stats.rxparity)
            sp += sprintf(sp, " pe:%d", (int) portp->stats.rxparity);
      if (portp->stats.rxbreaks)
            sp += sprintf(sp, " brk:%d", (int) portp->stats.rxbreaks);
      if (portp->stats.rxoverrun)
            sp += sprintf(sp, " oe:%d", (int) portp->stats.rxoverrun);

      sigs = stl_getsignals(portp);
      cnt = sprintf(sp, "%s%s%s%s%s ",
            (sigs & TIOCM_RTS) ? "|RTS" : "",
            (sigs & TIOCM_CTS) ? "|CTS" : "",
            (sigs & TIOCM_DTR) ? "|DTR" : "",
            (sigs & TIOCM_CD) ? "|DCD" : "",
            (sigs & TIOCM_DSR) ? "|DSR" : "");
      *sp = ' ';
      sp += cnt;

      for (cnt = (sp - pos); (cnt < (MAXLINE - 1)); cnt++)
            *sp++ = ' ';
      if (cnt >= MAXLINE)
            pos[(MAXLINE - 2)] = '+';
      pos[(MAXLINE - 1)] = '\n';

      return MAXLINE;
}

/*****************************************************************************/

/*
 *    Port info, read from the /proc file system.
 */

static int stl_readproc(char *page, char **start, off_t off, int count, int *eof, void *data)
{
      stlbrd_t    *brdp;
      stlpanel_t  *panelp;
      stlport_t   *portp;
      int         brdnr, panelnr, portnr, totalport;
      int         curoff, maxoff;
      char        *pos;

#ifdef DEBUG
      printk("stl_readproc(page=%x,start=%x,off=%x,count=%d,eof=%x,"
            "data=%x\n", (int) page, (int) start, (int) off, count,
            (int) eof, (int) data);
#endif

      pos = page;
      totalport = 0;
      curoff = 0;

      if (off == 0) {
            pos += sprintf(pos, "%s: version %s", stl_drvtitle,
                  stl_drvversion);
            while (pos < (page + MAXLINE - 1))
                  *pos++ = ' ';
            *pos++ = '\n';
      }
      curoff =  MAXLINE;

/*
 *    We scan through for each board, panel and port. The offset is
 *    calculated on the fly, and irrelevant ports are skipped.
 */
      for (brdnr = 0; (brdnr < stl_nrbrds); brdnr++) {
            brdp = stl_brds[brdnr];
            if (brdp == (stlbrd_t *) NULL)
                  continue;
            if (brdp->state == 0)
                  continue;

            maxoff = curoff + (brdp->nrports * MAXLINE);
            if (off >= maxoff) {
                  curoff = maxoff;
                  continue;
            }

            totalport = brdnr * STL_MAXPORTS;
            for (panelnr = 0; (panelnr < brdp->nrpanels); panelnr++) {
                  panelp = brdp->panels[panelnr];
                  if (panelp == (stlpanel_t *) NULL)
                        continue;

                  maxoff = curoff + (panelp->nrports * MAXLINE);
                  if (off >= maxoff) {
                        curoff = maxoff;
                        totalport += panelp->nrports;
                        continue;
                  }

                  for (portnr = 0; (portnr < panelp->nrports); portnr++,
                      totalport++) {
                        portp = panelp->ports[portnr];
                        if (portp == (stlport_t *) NULL)
                              continue;
                        if (off >= (curoff += MAXLINE))
                              continue;
                        if ((pos - page + MAXLINE) > count)
                              goto stl_readdone;
                        pos += stl_portinfo(portp, totalport, pos);
                  }
            }
      }

      *eof = 1;

stl_readdone:
      *start = page;
      return (pos - page);
}

/*****************************************************************************/

/*
 *    All board interrupts are vectored through here first. This code then
 *    calls off to the approrpriate board interrupt handlers.
 */

static irqreturn_t stl_intr(int irq, void *dev_id, struct pt_regs *regs)
{
      stlbrd_t    *brdp = (stlbrd_t *) dev_id;

#ifdef DEBUG
      printk("stl_intr(brdp=%x,irq=%d,regs=%x)\n", (int) brdp, irq,
          (int) regs);
#endif

      return IRQ_RETVAL((* brdp->isr)(brdp));
}

/*****************************************************************************/

/*
 *    Interrupt service routine for EasyIO board types.
 */

static int stl_eiointr(stlbrd_t *brdp)
{
      stlpanel_t  *panelp;
      unsigned int      iobase;
      int         handled = 0;

      spin_lock(&brd_lock);
      panelp = brdp->panels[0];
      iobase = panelp->iobase;
      while (inb(brdp->iostatus) & EIO_INTRPEND) {
            handled = 1;
            (* panelp->isr)(panelp, iobase);
      }
      spin_unlock(&brd_lock);
      return handled;
}

/*****************************************************************************/

/*
 *    Interrupt service routine for ECH-AT board types.
 */

static int stl_echatintr(stlbrd_t *brdp)
{
      stlpanel_t  *panelp;
      unsigned int      ioaddr;
      int         bnknr;
      int         handled = 0;

      outb((brdp->ioctrlval | ECH_BRDENABLE), brdp->ioctrl);

      while (inb(brdp->iostatus) & ECH_INTRPEND) {
            handled = 1;
            for (bnknr = 0; (bnknr < brdp->nrbnks); bnknr++) {
                  ioaddr = brdp->bnkstataddr[bnknr];
                  if (inb(ioaddr) & ECH_PNLINTRPEND) {
                        panelp = brdp->bnk2panel[bnknr];
                        (* panelp->isr)(panelp, (ioaddr & 0xfffc));
                  }
            }
      }

      outb((brdp->ioctrlval | ECH_BRDDISABLE), brdp->ioctrl);

      return handled;
}

/*****************************************************************************/

/*
 *    Interrupt service routine for ECH-MCA board types.
 */

static int stl_echmcaintr(stlbrd_t *brdp)
{
      stlpanel_t  *panelp;
      unsigned int      ioaddr;
      int         bnknr;
      int         handled = 0;

      while (inb(brdp->iostatus) & ECH_INTRPEND) {
            handled = 1;
            for (bnknr = 0; (bnknr < brdp->nrbnks); bnknr++) {
                  ioaddr = brdp->bnkstataddr[bnknr];
                  if (inb(ioaddr) & ECH_PNLINTRPEND) {
                        panelp = brdp->bnk2panel[bnknr];
                        (* panelp->isr)(panelp, (ioaddr & 0xfffc));
                  }
            }
      }
      return handled;
}

/*****************************************************************************/

/*
 *    Interrupt service routine for ECH-PCI board types.
 */

static int stl_echpciintr(stlbrd_t *brdp)
{
      stlpanel_t  *panelp;
      unsigned int      ioaddr;
      int         bnknr, recheck;
      int         handled = 0;

      while (1) {
            recheck = 0;
            for (bnknr = 0; (bnknr < brdp->nrbnks); bnknr++) {
                  outb(brdp->bnkpageaddr[bnknr], brdp->ioctrl);
                  ioaddr = brdp->bnkstataddr[bnknr];
                  if (inb(ioaddr) & ECH_PNLINTRPEND) {
                        panelp = brdp->bnk2panel[bnknr];
                        (* panelp->isr)(panelp, (ioaddr & 0xfffc));
                        recheck++;
                        handled = 1;
                  }
            }
            if (! recheck)
                  break;
      }
      return handled;
}

/*****************************************************************************/

/*
 *    Interrupt service routine for ECH-8/64-PCI board types.
 */

static int stl_echpci64intr(stlbrd_t *brdp)
{
      stlpanel_t  *panelp;
      unsigned int      ioaddr;
      int         bnknr;
      int         handled = 0;

      while (inb(brdp->ioctrl) & 0x1) {
            handled = 1;
            for (bnknr = 0; (bnknr < brdp->nrbnks); bnknr++) {
                  ioaddr = brdp->bnkstataddr[bnknr];
                  if (inb(ioaddr) & ECH_PNLINTRPEND) {
                        panelp = brdp->bnk2panel[bnknr];
                        (* panelp->isr)(panelp, (ioaddr & 0xfffc));
                  }
            }
      }

      return handled;
}

/*****************************************************************************/

/*
 *    Service an off-level request for some channel.
 */
static void stl_offintr(void *private)
{
      stlport_t         *portp;
      struct tty_struct *tty;
      unsigned int            oldsigs;

      portp = private;

#ifdef DEBUG
      printk("stl_offintr(portp=%x)\n", (int) portp);
#endif

      if (portp == (stlport_t *) NULL)
            return;

      tty = portp->tty;
      if (tty == (struct tty_struct *) NULL)
            return;

      lock_kernel();
      if (test_bit(ASYI_TXLOW, &portp->istate)) {
            tty_wakeup(tty);
      }
      if (test_bit(ASYI_DCDCHANGE, &portp->istate)) {
            clear_bit(ASYI_DCDCHANGE, &portp->istate);
            oldsigs = portp->sigs;
            portp->sigs = stl_getsignals(portp);
            if ((portp->sigs & TIOCM_CD) && ((oldsigs & TIOCM_CD) == 0))
                  wake_up_interruptible(&portp->open_wait);
            if ((oldsigs & TIOCM_CD) && ((portp->sigs & TIOCM_CD) == 0)) {
                  if (portp->flags & ASYNC_CHECK_CD)
                        tty_hangup(tty);  /* FIXME: module removal race here - AKPM */
            }
      }
      unlock_kernel();
}

/*****************************************************************************/

/*
 *    Initialize all the ports on a panel.
 */

static int __init stl_initports(stlbrd_t *brdp, stlpanel_t *panelp)
{
      stlport_t   *portp;
      int         chipmask, i;

#ifdef DEBUG
      printk("stl_initports(brdp=%x,panelp=%x)\n", (int) brdp, (int) panelp);
#endif

      chipmask = stl_panelinit(brdp, panelp);

/*
 *    All UART's are initialized (if found!). Now go through and setup
 *    each ports data structures.
 */
      for (i = 0; (i < panelp->nrports); i++) {
            portp = kzalloc(sizeof(stlport_t), GFP_KERNEL);
            if (!portp) {
                  printk("STALLION: failed to allocate memory "
                        "(size=%Zd)\n", sizeof(stlport_t));
                  break;
            }

            portp->magic = STL_PORTMAGIC;
            portp->portnr = i;
            portp->brdnr = panelp->brdnr;
            portp->panelnr = panelp->panelnr;
            portp->uartp = panelp->uartp;
            portp->clk = brdp->clk;
            portp->baud_base = STL_BAUDBASE;
            portp->close_delay = STL_CLOSEDELAY;
            portp->closing_wait = 30 * HZ;
            INIT_WORK(&portp->tqueue, stl_offintr, portp);
            init_waitqueue_head(&portp->open_wait);
            init_waitqueue_head(&portp->close_wait);
            portp->stats.brd = portp->brdnr;
            portp->stats.panel = portp->panelnr;
            portp->stats.port = portp->portnr;
            panelp->ports[i] = portp;
            stl_portinit(brdp, panelp, portp);
      }

      return(0);
}

/*****************************************************************************/

/*
 *    Try to find and initialize an EasyIO board.
 */

static inline int stl_initeio(stlbrd_t *brdp)
{
      stlpanel_t  *panelp;
      unsigned int      status;
      char        *name;
      int         rc;

#ifdef DEBUG
      printk("stl_initeio(brdp=%x)\n", (int) brdp);
#endif

      brdp->ioctrl = brdp->ioaddr1 + 1;
      brdp->iostatus = brdp->ioaddr1 + 2;

      status = inb(brdp->iostatus);
      if ((status & EIO_IDBITMASK) == EIO_MK3)
            brdp->ioctrl++;

/*
 *    Handle board specific stuff now. The real difference is PCI
 *    or not PCI.
 */
      if (brdp->brdtype == BRD_EASYIOPCI) {
            brdp->iosize1 = 0x80;
            brdp->iosize2 = 0x80;
            name = "serial(EIO-PCI)";
            outb(0x41, (brdp->ioaddr2 + 0x4c));
      } else {
            brdp->iosize1 = 8;
            name = "serial(EIO)";
            if ((brdp->irq < 0) || (brdp->irq > 15) ||
                (stl_vecmap[brdp->irq] == (unsigned char) 0xff)) {
                  printk("STALLION: invalid irq=%d for brd=%d\n",
                        brdp->irq, brdp->brdnr);
                  return(-EINVAL);
            }
            outb((stl_vecmap[brdp->irq] | EIO_0WS |
                  ((brdp->irqtype) ? EIO_INTLEVEL : EIO_INTEDGE)),
                  brdp->ioctrl);
      }

      if (!request_region(brdp->ioaddr1, brdp->iosize1, name)) {
            printk(KERN_WARNING "STALLION: Warning, board %d I/O address "
                  "%x conflicts with another device\n", brdp->brdnr, 
                  brdp->ioaddr1);
            return(-EBUSY);
      }
      
      if (brdp->iosize2 > 0)
            if (!request_region(brdp->ioaddr2, brdp->iosize2, name)) {
                  printk(KERN_WARNING "STALLION: Warning, board %d I/O "
                        "address %x conflicts with another device\n",
                        brdp->brdnr, brdp->ioaddr2);
                  printk(KERN_WARNING "STALLION: Warning, also "
                        "releasing board %d I/O address %x \n", 
                        brdp->brdnr, brdp->ioaddr1);
                  release_region(brdp->ioaddr1, brdp->iosize1);
                  return(-EBUSY);
            }

/*
 *    Everything looks OK, so let's go ahead and probe for the hardware.
 */
      brdp->clk = CD1400_CLK;
      brdp->isr = stl_eiointr;

      switch (status & EIO_IDBITMASK) {
      case EIO_8PORTM:
            brdp->clk = CD1400_CLK8M;
            /* fall thru */
      case EIO_8PORTRS:
      case EIO_8PORTDI:
            brdp->nrports = 8;
            break;
      case EIO_4PORTRS:
            brdp->nrports = 4;
            break;
      case EIO_MK3:
            switch (status & EIO_BRDMASK) {
            case ID_BRD4:
                  brdp->nrports = 4;
                  break;
            case ID_BRD8:
                  brdp->nrports = 8;
                  break;
            case ID_BRD16:
                  brdp->nrports = 16;
                  break;
            default:
                  return(-ENODEV);
            }
            break;
      default:
            return(-ENODEV);
      }

/*
 *    We have verified that the board is actually present, so now we
 *    can complete the setup.
 */

      panelp = kzalloc(sizeof(stlpanel_t), GFP_KERNEL);
      if (!panelp) {
            printk(KERN_WARNING "STALLION: failed to allocate memory "
                  "(size=%Zd)\n", sizeof(stlpanel_t));
            return -ENOMEM;
      }

      panelp->magic = STL_PANELMAGIC;
      panelp->brdnr = brdp->brdnr;
      panelp->panelnr = 0;
      panelp->nrports = brdp->nrports;
      panelp->iobase = brdp->ioaddr1;
      panelp->hwid = status;
      if ((status & EIO_IDBITMASK) == EIO_MK3) {
            panelp->uartp = (void *) &stl_sc26198uart;
            panelp->isr = stl_sc26198intr;
      } else {
            panelp->uartp = (void *) &stl_cd1400uart;
            panelp->isr = stl_cd1400eiointr;
      }

      brdp->panels[0] = panelp;
      brdp->nrpanels = 1;
      brdp->state |= BRD_FOUND;
      brdp->hwid = status;
      if (request_irq(brdp->irq, stl_intr, IRQF_SHARED, name, brdp) != 0) {
            printk("STALLION: failed to register interrupt "
                "routine for %s irq=%d\n", name, brdp->irq);
            rc = -ENODEV;
      } else {
            rc = 0;
      }
      return rc;
}

/*****************************************************************************/

/*
 *    Try to find an ECH board and initialize it. This code is capable of
 *    dealing with all types of ECH board.
 */

static inline int stl_initech(stlbrd_t *brdp)
{
      stlpanel_t  *panelp;
      unsigned int      status, nxtid, ioaddr, conflict;
      int         panelnr, banknr, i;
      char        *name;

#ifdef DEBUG
      printk("stl_initech(brdp=%x)\n", (int) brdp);
#endif

      status = 0;
      conflict = 0;

/*
 *    Set up the initial board register contents for boards. This varies a
 *    bit between the different board types. So we need to handle each
 *    separately. Also do a check that the supplied IRQ is good.
 */
      switch (brdp->brdtype) {

      case BRD_ECH:
            brdp->isr = stl_echatintr;
            brdp->ioctrl = brdp->ioaddr1 + 1;
            brdp->iostatus = brdp->ioaddr1 + 1;
            status = inb(brdp->iostatus);
            if ((status & ECH_IDBITMASK) != ECH_ID)
                  return(-ENODEV);
            if ((brdp->irq < 0) || (brdp->irq > 15) ||
                (stl_vecmap[brdp->irq] == (unsigned char) 0xff)) {
                  printk("STALLION: invalid irq=%d for brd=%d\n",
                        brdp->irq, brdp->brdnr);
                  return(-EINVAL);
            }
            status = ((brdp->ioaddr2 & ECH_ADDR2MASK) >> 1);
            status |= (stl_vecmap[brdp->irq] << 1);
            outb((status | ECH_BRDRESET), brdp->ioaddr1);
            brdp->ioctrlval = ECH_INTENABLE |
                  ((brdp->irqtype) ? ECH_INTLEVEL : ECH_INTEDGE);
            for (i = 0; (i < 10); i++)
                  outb((brdp->ioctrlval | ECH_BRDENABLE), brdp->ioctrl);
            brdp->iosize1 = 2;
            brdp->iosize2 = 32;
            name = "serial(EC8/32)";
            outb(status, brdp->ioaddr1);
            break;

      case BRD_ECHMC:
            brdp->isr = stl_echmcaintr;
            brdp->ioctrl = brdp->ioaddr1 + 0x20;
            brdp->iostatus = brdp->ioctrl;
            status = inb(brdp->iostatus);
            if ((status & ECH_IDBITMASK) != ECH_ID)
                  return(-ENODEV);
            if ((brdp->irq < 0) || (brdp->irq > 15) ||
                (stl_vecmap[brdp->irq] == (unsigned char) 0xff)) {
                  printk("STALLION: invalid irq=%d for brd=%d\n",
                        brdp->irq, brdp->brdnr);
                  return(-EINVAL);
            }
            outb(ECHMC_BRDRESET, brdp->ioctrl);
            outb(ECHMC_INTENABLE, brdp->ioctrl);
            brdp->iosize1 = 64;
            name = "serial(EC8/32-MC)";
            break;

      case BRD_ECHPCI:
            brdp->isr = stl_echpciintr;
            brdp->ioctrl = brdp->ioaddr1 + 2;
            brdp->iosize1 = 4;
            brdp->iosize2 = 8;
            name = "serial(EC8/32-PCI)";
            break;

      case BRD_ECH64PCI:
            brdp->isr = stl_echpci64intr;
            brdp->ioctrl = brdp->ioaddr2 + 0x40;
            outb(0x43, (brdp->ioaddr1 + 0x4c));
            brdp->iosize1 = 0x80;
            brdp->iosize2 = 0x80;
            name = "serial(EC8/64-PCI)";
            break;

      default:
            printk("STALLION: unknown board type=%d\n", brdp->brdtype);
            return(-EINVAL);
            break;
      }

/*
 *    Check boards for possible IO address conflicts and return fail status 
 *    if an IO conflict found.
 */
      if (!request_region(brdp->ioaddr1, brdp->iosize1, name)) {
            printk(KERN_WARNING "STALLION: Warning, board %d I/O address "
                  "%x conflicts with another device\n", brdp->brdnr, 
                  brdp->ioaddr1);
            return(-EBUSY);
      }
      
      if (brdp->iosize2 > 0)
            if (!request_region(brdp->ioaddr2, brdp->iosize2, name)) {
                  printk(KERN_WARNING "STALLION: Warning, board %d I/O "
                        "address %x conflicts with another device\n",
                        brdp->brdnr, brdp->ioaddr2);
                  printk(KERN_WARNING "STALLION: Warning, also "
                        "releasing board %d I/O address %x \n", 
                        brdp->brdnr, brdp->ioaddr1);
                  release_region(brdp->ioaddr1, brdp->iosize1);
                  return(-EBUSY);
            }

/*
 *    Scan through the secondary io address space looking for panels.
 *    As we find'em allocate and initialize panel structures for each.
 */
      brdp->clk = CD1400_CLK;
      brdp->hwid = status;

      ioaddr = brdp->ioaddr2;
      banknr = 0;
      panelnr = 0;
      nxtid = 0;

      for (i = 0; (i < STL_MAXPANELS); i++) {
            if (brdp->brdtype == BRD_ECHPCI) {
                  outb(nxtid, brdp->ioctrl);
                  ioaddr = brdp->ioaddr2;
            }
            status = inb(ioaddr + ECH_PNLSTATUS);
            if ((status & ECH_PNLIDMASK) != nxtid)
                  break;
            panelp = kzalloc(sizeof(stlpanel_t), GFP_KERNEL);
            if (!panelp) {
                  printk("STALLION: failed to allocate memory "
                        "(size=%Zd)\n", sizeof(stlpanel_t));
                  break;
            }
            panelp->magic = STL_PANELMAGIC;
            panelp->brdnr = brdp->brdnr;
            panelp->panelnr = panelnr;
            panelp->iobase = ioaddr;
            panelp->pagenr = nxtid;
            panelp->hwid = status;
            brdp->bnk2panel[banknr] = panelp;
            brdp->bnkpageaddr[banknr] = nxtid;
            brdp->bnkstataddr[banknr++] = ioaddr + ECH_PNLSTATUS;

            if (status & ECH_PNLXPID) {
                  panelp->uartp = (void *) &stl_sc26198uart;
                  panelp->isr = stl_sc26198intr;
                  if (status & ECH_PNL16PORT) {
                        panelp->nrports = 16;
                        brdp->bnk2panel[banknr] = panelp;
                        brdp->bnkpageaddr[banknr] = nxtid;
                        brdp->bnkstataddr[banknr++] = ioaddr + 4 +
                              ECH_PNLSTATUS;
                  } else {
                        panelp->nrports = 8;
                  }
            } else {
                  panelp->uartp = (void *) &stl_cd1400uart;
                  panelp->isr = stl_cd1400echintr;
                  if (status & ECH_PNL16PORT) {
                        panelp->nrports = 16;
                        panelp->ackmask = 0x80;
                        if (brdp->brdtype != BRD_ECHPCI)
                              ioaddr += EREG_BANKSIZE;
                        brdp->bnk2panel[banknr] = panelp;
                        brdp->bnkpageaddr[banknr] = ++nxtid;
                        brdp->bnkstataddr[banknr++] = ioaddr +
                              ECH_PNLSTATUS;
                  } else {
                        panelp->nrports = 8;
                        panelp->ackmask = 0xc0;
                  }
            }

            nxtid++;
            ioaddr += EREG_BANKSIZE;
            brdp->nrports += panelp->nrports;
            brdp->panels[panelnr++] = panelp;
            if ((brdp->brdtype != BRD_ECHPCI) &&
                (ioaddr >= (brdp->ioaddr2 + brdp->iosize2)))
                  break;
      }

      brdp->nrpanels = panelnr;
      brdp->nrbnks = banknr;
      if (brdp->brdtype == BRD_ECH)
            outb((brdp->ioctrlval | ECH_BRDDISABLE), brdp->ioctrl);

      brdp->state |= BRD_FOUND;
      if (request_irq(brdp->irq, stl_intr, IRQF_SHARED, name, brdp) != 0) {
            printk("STALLION: failed to register interrupt "
                "routine for %s irq=%d\n", name, brdp->irq);
            i = -ENODEV;
      } else {
            i = 0;
      }

      return(i);
}

/*****************************************************************************/

/*
 *    Initialize and configure the specified board.
 *    Scan through all the boards in the configuration and see what we
 *    can find. Handle EIO and the ECH boards a little differently here
 *    since the initial search and setup is very different.
 */

static int __init stl_brdinit(stlbrd_t *brdp)
{
      int   i;

#ifdef DEBUG
      printk("stl_brdinit(brdp=%x)\n", (int) brdp);
#endif

      switch (brdp->brdtype) {
      case BRD_EASYIO:
      case BRD_EASYIOPCI:
            stl_initeio(brdp);
            break;
      case BRD_ECH:
      case BRD_ECHMC:
      case BRD_ECHPCI:
      case BRD_ECH64PCI:
            stl_initech(brdp);
            break;
      default:
            printk("STALLION: board=%d is unknown board type=%d\n",
                  brdp->brdnr, brdp->brdtype);
            return(ENODEV);
      }

      stl_brds[brdp->brdnr] = brdp;
      if ((brdp->state & BRD_FOUND) == 0) {
            printk("STALLION: %s board not found, board=%d io=%x irq=%d\n",
                  stl_brdnames[brdp->brdtype], brdp->brdnr,
                  brdp->ioaddr1, brdp->irq);
            return(ENODEV);
      }

      for (i = 0; (i < STL_MAXPANELS); i++)
            if (brdp->panels[i] != (stlpanel_t *) NULL)
                  stl_initports(brdp, brdp->panels[i]);

      printk("STALLION: %s found, board=%d io=%x irq=%d "
            "nrpanels=%d nrports=%d\n", stl_brdnames[brdp->brdtype],
            brdp->brdnr, brdp->ioaddr1, brdp->irq, brdp->nrpanels,
            brdp->nrports);
      return(0);
}

/*****************************************************************************/

/*
 *    Find the next available board number that is free.
 */

static inline int stl_getbrdnr(void)
{
      int   i;

      for (i = 0; (i < STL_MAXBRDS); i++) {
            if (stl_brds[i] == (stlbrd_t *) NULL) {
                  if (i >= stl_nrbrds)
                        stl_nrbrds = i + 1;
                  return(i);
            }
      }
      return(-1);
}

/*****************************************************************************/

#ifdef      CONFIG_PCI

/*
 *    We have a Stallion board. Allocate a board structure and
 *    initialize it. Read its IO and IRQ resources from PCI
 *    configuration space.
 */

static inline int stl_initpcibrd(int brdtype, struct pci_dev *devp)
{
      stlbrd_t    *brdp;

#ifdef DEBUG
      printk("stl_initpcibrd(brdtype=%d,busnr=%x,devnr=%x)\n", brdtype,
            devp->bus->number, devp->devfn);
#endif

      if (pci_enable_device(devp))
            return(-EIO);
      if ((brdp = stl_allocbrd()) == (stlbrd_t *) NULL)
            return(-ENOMEM);
      if ((brdp->brdnr = stl_getbrdnr()) < 0) {
            printk("STALLION: too many boards found, "
                  "maximum supported %d\n", STL_MAXBRDS);
            return(0);
      }
      brdp->brdtype = brdtype;

/*
 *    Different Stallion boards use the BAR registers in different ways,
 *    so set up io addresses based on board type.
 */
#ifdef DEBUG
      printk("%s(%d): BAR[]=%x,%x,%x,%x IRQ=%x\n", __FILE__, __LINE__,
            pci_resource_start(devp, 0), pci_resource_start(devp, 1),
            pci_resource_start(devp, 2), pci_resource_start(devp, 3), devp->irq);
#endif

/*
 *    We have all resources from the board, so let's setup the actual
 *    board structure now.
 */
      switch (brdtype) {
      case BRD_ECHPCI:
            brdp->ioaddr2 = pci_resource_start(devp, 0);
            brdp->ioaddr1 = pci_resource_start(devp, 1);
            break;
      case BRD_ECH64PCI:
            brdp->ioaddr2 = pci_resource_start(devp, 2);
            brdp->ioaddr1 = pci_resource_start(devp, 1);
            break;
      case BRD_EASYIOPCI:
            brdp->ioaddr1 = pci_resource_start(devp, 2);
            brdp->ioaddr2 = pci_resource_start(devp, 1);
            break;
      default:
            printk("STALLION: unknown PCI board type=%d\n", brdtype);
            break;
      }

      brdp->irq = devp->irq;
      stl_brdinit(brdp);

      return(0);
}

/*****************************************************************************/

/*
 *    Find all Stallion PCI boards that might be installed. Initialize each
 *    one as it is found.
 */


static inline int stl_findpcibrds(void)
{
      struct pci_dev    *dev = NULL;
      int         i, rc;

#ifdef DEBUG
      printk("stl_findpcibrds()\n");
#endif

      for (i = 0; (i < stl_nrpcibrds); i++)
            while ((dev = pci_find_device(stl_pcibrds[i].vendid,
                stl_pcibrds[i].devid, dev))) {

/*
 *                Found a device on the PCI bus that has our vendor and
 *                device ID. Need to check now that it is really us.
 */
                  if ((dev->class >> 8) == PCI_CLASS_STORAGE_IDE)
                        continue;

                  rc = stl_initpcibrd(stl_pcibrds[i].brdtype, dev);
                  if (rc)
                        return(rc);
            }

      return(0);
}

#endif

/*****************************************************************************/

/*
 *    Scan through all the boards in the configuration and see what we
 *    can find. Handle EIO and the ECH boards a little differently here
 *    since the initial search and setup is too different.
 */

static inline int stl_initbrds(void)
{
      stlbrd_t    *brdp;
      stlconf_t   *confp;
      int         i;

#ifdef DEBUG
      printk("stl_initbrds()\n");
#endif

      if (stl_nrbrds > STL_MAXBRDS) {
            printk("STALLION: too many boards in configuration table, "
                  "truncating to %d\n", STL_MAXBRDS);
            stl_nrbrds = STL_MAXBRDS;
      }

/*
 *    Firstly scan the list of static boards configured. Allocate
 *    resources and initialize the boards as found.
 */
      for (i = 0; (i < stl_nrbrds); i++) {
            confp = &stl_brdconf[i];
            stl_parsebrd(confp, stl_brdsp[i]);
            if ((brdp = stl_allocbrd()) == (stlbrd_t *) NULL)
                  return(-ENOMEM);
            brdp->brdnr = i;
            brdp->brdtype = confp->brdtype;
            brdp->ioaddr1 = confp->ioaddr1;
            brdp->ioaddr2 = confp->ioaddr2;
            brdp->irq = confp->irq;
            brdp->irqtype = confp->irqtype;
            stl_brdinit(brdp);
      }

/*
 *    Find any dynamically supported boards. That is via module load
 *    line options or auto-detected on the PCI bus.
 */
      stl_argbrds();
#ifdef CONFIG_PCI
      stl_findpcibrds();
#endif

      return(0);
}

/*****************************************************************************/

/*
 *    Return the board stats structure to user app.
 */

static int stl_getbrdstats(combrd_t __user *bp)
{
      stlbrd_t    *brdp;
      stlpanel_t  *panelp;
      int         i;

      if (copy_from_user(&stl_brdstats, bp, sizeof(combrd_t)))
            return -EFAULT;
      if (stl_brdstats.brd >= STL_MAXBRDS)
            return(-ENODEV);
      brdp = stl_brds[stl_brdstats.brd];
      if (brdp == (stlbrd_t *) NULL)
            return(-ENODEV);

      memset(&stl_brdstats, 0, sizeof(combrd_t));
      stl_brdstats.brd = brdp->brdnr;
      stl_brdstats.type = brdp->brdtype;
      stl_brdstats.hwid = brdp->hwid;
      stl_brdstats.state = brdp->state;
      stl_brdstats.ioaddr = brdp->ioaddr1;
      stl_brdstats.ioaddr2 = brdp->ioaddr2;
      stl_brdstats.irq = brdp->irq;
      stl_brdstats.nrpanels = brdp->nrpanels;
      stl_brdstats.nrports = brdp->nrports;
      for (i = 0; (i < brdp->nrpanels); i++) {
            panelp = brdp->panels[i];
            stl_brdstats.panels[i].panel = i;
            stl_brdstats.panels[i].hwid = panelp->hwid;
            stl_brdstats.panels[i].nrports = panelp->nrports;
      }

      return copy_to_user(bp, &stl_brdstats, sizeof(combrd_t)) ? -EFAULT : 0;
}

/*****************************************************************************/

/*
 *    Resolve the referenced port number into a port struct pointer.
 */

static stlport_t *stl_getport(int brdnr, int panelnr, int portnr)
{
      stlbrd_t    *brdp;
      stlpanel_t  *panelp;

      if ((brdnr < 0) || (brdnr >= STL_MAXBRDS))
            return((stlport_t *) NULL);
      brdp = stl_brds[brdnr];
      if (brdp == (stlbrd_t *) NULL)
            return((stlport_t *) NULL);
      if ((panelnr < 0) || (panelnr >= brdp->nrpanels))
            return((stlport_t *) NULL);
      panelp = brdp->panels[panelnr];
      if (panelp == (stlpanel_t *) NULL)
            return((stlport_t *) NULL);
      if ((portnr < 0) || (portnr >= panelp->nrports))
            return((stlport_t *) NULL);
      return(panelp->ports[portnr]);
}

/*****************************************************************************/

/*
 *    Return the port stats structure to user app. A NULL port struct
 *    pointer passed in means that we need to find out from the app
 *    what port to get stats for (used through board control device).
 */

static int stl_getportstats(stlport_t *portp, comstats_t __user *cp)
{
      unsigned char     *head, *tail;
      unsigned long     flags;

      if (!portp) {
            if (copy_from_user(&stl_comstats, cp, sizeof(comstats_t)))
                  return -EFAULT;
            portp = stl_getport(stl_comstats.brd, stl_comstats.panel,
                  stl_comstats.port);
            if (portp == (stlport_t *) NULL)
                  return(-ENODEV);
      }

      portp->stats.state = portp->istate;
      portp->stats.flags = portp->flags;
      portp->stats.hwid = portp->hwid;

      portp->stats.ttystate = 0;
      portp->stats.cflags = 0;
      portp->stats.iflags = 0;
      portp->stats.oflags = 0;
      portp->stats.lflags = 0;
      portp->stats.rxbuffered = 0;

      spin_lock_irqsave(&stallion_lock, flags);
      if (portp->tty != (struct tty_struct *) NULL) {
            if (portp->tty->driver_data == portp) {
                  portp->stats.ttystate = portp->tty->flags;
                  /* No longer available as a statistic */
                  portp->stats.rxbuffered = 1; /*portp->tty->flip.count; */
                  if (portp->tty->termios != (struct termios *) NULL) {
                        portp->stats.cflags = portp->tty->termios->c_cflag;
                        portp->stats.iflags = portp->tty->termios->c_iflag;
                        portp->stats.oflags = portp->tty->termios->c_oflag;
                        portp->stats.lflags = portp->tty->termios->c_lflag;
                  }
            }
      }
      spin_unlock_irqrestore(&stallion_lock, flags);

      head = portp->tx.head;
      tail = portp->tx.tail;
      portp->stats.txbuffered = ((head >= tail) ? (head - tail) :
            (STL_TXBUFSIZE - (tail - head)));

      portp->stats.signals = (unsigned long) stl_getsignals(portp);

      return copy_to_user(cp, &portp->stats,
                      sizeof(comstats_t)) ? -EFAULT : 0;
}

/*****************************************************************************/

/*
 *    Clear the port stats structure. We also return it zeroed out...
 */

static int stl_clrportstats(stlport_t *portp, comstats_t __user *cp)
{
      if (!portp) {
            if (copy_from_user(&stl_comstats, cp, sizeof(comstats_t)))
                  return -EFAULT;
            portp = stl_getport(stl_comstats.brd, stl_comstats.panel,
                  stl_comstats.port);
            if (portp == (stlport_t *) NULL)
                  return(-ENODEV);
      }

      memset(&portp->stats, 0, sizeof(comstats_t));
      portp->stats.brd = portp->brdnr;
      portp->stats.panel = portp->panelnr;
      portp->stats.port = portp->portnr;
      return copy_to_user(cp, &portp->stats,
                      sizeof(comstats_t)) ? -EFAULT : 0;
}

/*****************************************************************************/

/*
 *    Return the entire driver ports structure to a user app.
 */

static int stl_getportstruct(stlport_t __user *arg)
{
      stlport_t   *portp;

      if (copy_from_user(&stl_dummyport, arg, sizeof(stlport_t)))
            return -EFAULT;
      portp = stl_getport(stl_dummyport.brdnr, stl_dummyport.panelnr,
             stl_dummyport.portnr);
      if (!portp)
            return -ENODEV;
      return copy_to_user(arg, portp, sizeof(stlport_t)) ? -EFAULT : 0;
}

/*****************************************************************************/

/*
 *    Return the entire driver board structure to a user app.
 */

static int stl_getbrdstruct(stlbrd_t __user *arg)
{
      stlbrd_t    *brdp;

      if (copy_from_user(&stl_dummybrd, arg, sizeof(stlbrd_t)))
            return -EFAULT;
      if ((stl_dummybrd.brdnr < 0) || (stl_dummybrd.brdnr >= STL_MAXBRDS))
            return -ENODEV;
      brdp = stl_brds[stl_dummybrd.brdnr];
      if (!brdp)
            return(-ENODEV);
      return copy_to_user(arg, brdp, sizeof(stlbrd_t)) ? -EFAULT : 0;
}

/*****************************************************************************/

/*
 *    The "staliomem" device is also required to do some special operations
 *    on the board and/or ports. In this driver it is mostly used for stats
 *    collection.
 */

static int stl_memioctl(struct inode *ip, struct file *fp, unsigned int cmd, unsigned long arg)
{
      int   brdnr, rc;
      void __user *argp = (void __user *)arg;

#ifdef DEBUG
      printk("stl_memioctl(ip=%x,fp=%x,cmd=%x,arg=%x)\n", (int) ip,
            (int) fp, cmd, (int) arg);
#endif

      brdnr = iminor(ip);
      if (brdnr >= STL_MAXBRDS)
            return(-ENODEV);
      rc = 0;

      switch (cmd) {
      case COM_GETPORTSTATS:
            rc = stl_getportstats(NULL, argp);
            break;
      case COM_CLRPORTSTATS:
            rc = stl_clrportstats(NULL, argp);
            break;
      case COM_GETBRDSTATS:
            rc = stl_getbrdstats(argp);
            break;
      case COM_READPORT:
            rc = stl_getportstruct(argp);
            break;
      case COM_READBOARD:
            rc = stl_getbrdstruct(argp);
            break;
      default:
            rc = -ENOIOCTLCMD;
            break;
      }

      return(rc);
}

static struct tty_operations stl_ops = {
      .open = stl_open,
      .close = stl_close,
      .write = stl_write,
      .put_char = stl_putchar,
      .flush_chars = stl_flushchars,
      .write_room = stl_writeroom,
      .chars_in_buffer = stl_charsinbuffer,
      .ioctl = stl_ioctl,
      .set_termios = stl_settermios,
      .throttle = stl_throttle,
      .unthrottle = stl_unthrottle,
      .stop = stl_stop,
      .start = stl_start,
      .hangup = stl_hangup,
      .flush_buffer = stl_flushbuffer,
      .break_ctl = stl_breakctl,
      .wait_until_sent = stl_waituntilsent,
      .send_xchar = stl_sendxchar,
      .read_proc = stl_readproc,
      .tiocmget = stl_tiocmget,
      .tiocmset = stl_tiocmset,
};

/*****************************************************************************/

static int __init stl_init(void)
{
      int i;
      printk(KERN_INFO "%s: version %s\n", stl_drvtitle, stl_drvversion);

      spin_lock_init(&stallion_lock);
      spin_lock_init(&brd_lock);

      stl_initbrds();

      stl_serial = alloc_tty_driver(STL_MAXBRDS * STL_MAXPORTS);
      if (!stl_serial)
            return -1;

/*
 *    Set up a character driver for per board stuff. This is mainly used
 *    to do stats ioctls on the ports.
 */
      if (register_chrdev(STL_SIOMEMMAJOR, "staliomem", &stl_fsiomem))
            printk("STALLION: failed to register serial board device\n");

      stallion_class = class_create(THIS_MODULE, "staliomem");
      for (i = 0; i < 4; i++)
            class_device_create(stallion_class, NULL,
                            MKDEV(STL_SIOMEMMAJOR, i), NULL,
                            "staliomem%d", i);

      stl_serial->owner = THIS_MODULE;
      stl_serial->driver_name = stl_drvname;
      stl_serial->name = "ttyE";
      stl_serial->major = STL_SERIALMAJOR;
      stl_serial->minor_start = 0;
      stl_serial->type = TTY_DRIVER_TYPE_SERIAL;
      stl_serial->subtype = SERIAL_TYPE_NORMAL;
      stl_serial->init_termios = stl_deftermios;
      stl_serial->flags = TTY_DRIVER_REAL_RAW;
      tty_set_operations(stl_serial, &stl_ops);

      if (tty_register_driver(stl_serial)) {
            put_tty_driver(stl_serial);
            printk("STALLION: failed to register serial driver\n");
            return -1;
      }

      return 0;
}

/*****************************************************************************/
/*                       CD1400 HARDWARE FUNCTIONS                           */
/*****************************************************************************/

/*
 *    These functions get/set/update the registers of the cd1400 UARTs.
 *    Access to the cd1400 registers is via an address/data io port pair.
 *    (Maybe should make this inline...)
 */

static int stl_cd1400getreg(stlport_t *portp, int regnr)
{
      outb((regnr + portp->uartaddr), portp->ioaddr);
      return inb(portp->ioaddr + EREG_DATA);
}

static void stl_cd1400setreg(stlport_t *portp, int regnr, int value)
{
      outb((regnr + portp->uartaddr), portp->ioaddr);
      outb(value, portp->ioaddr + EREG_DATA);
}

static int stl_cd1400updatereg(stlport_t *portp, int regnr, int value)
{
      outb((regnr + portp->uartaddr), portp->ioaddr);
      if (inb(portp->ioaddr + EREG_DATA) != value) {
            outb(value, portp->ioaddr + EREG_DATA);
            return 1;
      }
      return 0;
}

/*****************************************************************************/

/*
 *    Inbitialize the UARTs in a panel. We don't care what sort of board
 *    these ports are on - since the port io registers are almost
 *    identical when dealing with ports.
 */

static int stl_cd1400panelinit(stlbrd_t *brdp, stlpanel_t *panelp)
{
      unsigned int      gfrcr;
      int         chipmask, i, j;
      int         nrchips, uartaddr, ioaddr;
      unsigned long   flags;

#ifdef DEBUG
      printk("stl_panelinit(brdp=%x,panelp=%x)\n", (int) brdp, (int) panelp);
#endif

      spin_lock_irqsave(&brd_lock, flags);
      BRDENABLE(panelp->brdnr, panelp->pagenr);

/*
 *    Check that each chip is present and started up OK.
 */
      chipmask = 0;
      nrchips = panelp->nrports / CD1400_PORTS;
      for (i = 0; (i < nrchips); i++) {
            if (brdp->brdtype == BRD_ECHPCI) {
                  outb((panelp->pagenr + (i >> 1)), brdp->ioctrl);
                  ioaddr = panelp->iobase;
            } else {
                  ioaddr = panelp->iobase + (EREG_BANKSIZE * (i >> 1));
            }
            uartaddr = (i & 0x01) ? 0x080 : 0;
            outb((GFRCR + uartaddr), ioaddr);
            outb(0, (ioaddr + EREG_DATA));
            outb((CCR + uartaddr), ioaddr);
            outb(CCR_RESETFULL, (ioaddr + EREG_DATA));
            outb(CCR_RESETFULL, (ioaddr + EREG_DATA));
            outb((GFRCR + uartaddr), ioaddr);
            for (j = 0; (j < CCR_MAXWAIT); j++) {
                  if ((gfrcr = inb(ioaddr + EREG_DATA)) != 0)
                        break;
            }
            if ((j >= CCR_MAXWAIT) || (gfrcr < 0x40) || (gfrcr > 0x60)) {
                  printk("STALLION: cd1400 not responding, "
                        "brd=%d panel=%d chip=%d\n",
                        panelp->brdnr, panelp->panelnr, i);
                  continue;
            }
            chipmask |= (0x1 << i);
            outb((PPR + uartaddr), ioaddr);
            outb(PPR_SCALAR, (ioaddr + EREG_DATA));
      }

      BRDDISABLE(panelp->brdnr);
      spin_unlock_irqrestore(&brd_lock, flags);
      return chipmask;
}

/*****************************************************************************/

/*
 *    Initialize hardware specific port registers.
 */

static void stl_cd1400portinit(stlbrd_t *brdp, stlpanel_t *panelp, stlport_t *portp)
{
      unsigned long flags;
#ifdef DEBUG
      printk("stl_cd1400portinit(brdp=%x,panelp=%x,portp=%x)\n",
            (int) brdp, (int) panelp, (int) portp);
#endif

      if ((brdp == (stlbrd_t *) NULL) || (panelp == (stlpanel_t *) NULL) ||
          (portp == (stlport_t *) NULL))
            return;

      spin_lock_irqsave(&brd_lock, flags);
      portp->ioaddr = panelp->iobase + (((brdp->brdtype == BRD_ECHPCI) ||
            (portp->portnr < 8)) ? 0 : EREG_BANKSIZE);
      portp->uartaddr = (portp->portnr & 0x04) << 5;
      portp->pagenr = panelp->pagenr + (portp->portnr >> 3);

      BRDENABLE(portp->brdnr, portp->pagenr);
      stl_cd1400setreg(portp, CAR, (portp->portnr & 0x03));
      stl_cd1400setreg(portp, LIVR, (portp->portnr << 3));
      portp->hwid = stl_cd1400getreg(portp, GFRCR);
      BRDDISABLE(portp->brdnr);
      spin_unlock_irqrestore(&brd_lock, flags);
}

/*****************************************************************************/

/*
 *    Wait for the command register to be ready. We will poll this,
 *    since it won't usually take too long to be ready.
 */

static void stl_cd1400ccrwait(stlport_t *portp)
{
      int   i;

      for (i = 0; (i < CCR_MAXWAIT); i++) {
            if (stl_cd1400getreg(portp, CCR) == 0) {
                  return;
            }
      }

      printk("STALLION: cd1400 not responding, port=%d panel=%d brd=%d\n",
            portp->portnr, portp->panelnr, portp->brdnr);
}

/*****************************************************************************/

/*
 *    Set up the cd1400 registers for a port based on the termios port
 *    settings.
 */

static void stl_cd1400setport(stlport_t *portp, struct termios *tiosp)
{
      stlbrd_t    *brdp;
      unsigned long     flags;
      unsigned int      clkdiv, baudrate;
      unsigned char     cor1, cor2, cor3;
      unsigned char     cor4, cor5, ccr;
      unsigned char     srer, sreron, sreroff;
      unsigned char     mcor1, mcor2, rtpr;
      unsigned char     clk, div;

      cor1 = 0;
      cor2 = 0;
      cor3 = 0;
      cor4 = 0;
      cor5 = 0;
      ccr = 0;
      rtpr = 0;
      clk = 0;
      div = 0;
      mcor1 = 0;
      mcor2 = 0;
      sreron = 0;
      sreroff = 0;

      brdp = stl_brds[portp->brdnr];
      if (brdp == (stlbrd_t *) NULL)
            return;

/*
 *    Set up the RX char ignore mask with those RX error types we
 *    can ignore. We can get the cd1400 to help us out a little here,
 *    it will ignore parity errors and breaks for us.
 */
      portp->rxignoremsk = 0;
      if (tiosp->c_iflag & IGNPAR) {
            portp->rxignoremsk |= (ST_PARITY | ST_FRAMING | ST_OVERRUN);
            cor1 |= COR1_PARIGNORE;
      }
      if (tiosp->c_iflag & IGNBRK) {
            portp->rxignoremsk |= ST_BREAK;
            cor4 |= COR4_IGNBRK;
      }

      portp->rxmarkmsk = ST_OVERRUN;
      if (tiosp->c_iflag & (INPCK | PARMRK))
            portp->rxmarkmsk |= (ST_PARITY | ST_FRAMING);
      if (tiosp->c_iflag & BRKINT)
            portp->rxmarkmsk |= ST_BREAK;

/*
 *    Go through the char size, parity and stop bits and set all the
 *    option register appropriately.
 */
      switch (tiosp->c_cflag & CSIZE) {
      case CS5:
            cor1 |= COR1_CHL5;
            break;
      case CS6:
            cor1 |= COR1_CHL6;
            break;
      case CS7:
            cor1 |= COR1_CHL7;
            break;
      default:
            cor1 |= COR1_CHL8;
            break;
      }

      if (tiosp->c_cflag & CSTOPB)
            cor1 |= COR1_STOP2;
      else
            cor1 |= COR1_STOP1;

      if (tiosp->c_cflag & PARENB) {
            if (tiosp->c_cflag & PARODD)
                  cor1 |= (COR1_PARENB | COR1_PARODD);
            else
                  cor1 |= (COR1_PARENB | COR1_PAREVEN);
      } else {
            cor1 |= COR1_PARNONE;
      }

/*
 *    Set the RX FIFO threshold at 6 chars. This gives a bit of breathing
 *    space for hardware flow control and the like. This should be set to
 *    VMIN. Also here we will set the RX data timeout to 10ms - this should
 *    really be based on VTIME.
 */
      cor3 |= FIFO_RXTHRESHOLD;
      rtpr = 2;

/*
 *    Calculate the baud rate timers. For now we will just assume that
 *    the input and output baud are the same. Could have used a baud
 *    table here, but this way we can generate virtually any baud rate
 *    we like!
 */
      baudrate = tiosp->c_cflag & CBAUD;
      if (baudrate & CBAUDEX) {
            baudrate &= ~CBAUDEX;
            if ((baudrate < 1) || (baudrate > 4))
                  tiosp->c_cflag &= ~CBAUDEX;
            else
                  baudrate += 15;
      }
      baudrate = stl_baudrates[baudrate];
      if ((tiosp->c_cflag & CBAUD) == B38400) {
            if ((portp->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
                  baudrate = 57600;
            else if ((portp->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
                  baudrate = 115200;
            else if ((portp->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
                  baudrate = 230400;
            else if ((portp->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
                  baudrate = 460800;
            else if ((portp->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
                  baudrate = (portp->baud_base / portp->custom_divisor);
      }
      if (baudrate > STL_CD1400MAXBAUD)
            baudrate = STL_CD1400MAXBAUD;

      if (baudrate > 0) {
            for (clk = 0; (clk < CD1400_NUMCLKS); clk++) {
                  clkdiv = ((portp->clk / stl_cd1400clkdivs[clk]) / baudrate);
                  if (clkdiv < 0x100)
                        break;
            }
            div = (unsigned char) clkdiv;
      }

/*
 *    Check what form of modem signaling is required and set it up.
 */
      if ((tiosp->c_cflag & CLOCAL) == 0) {
            mcor1 |= MCOR1_DCD;
            mcor2 |= MCOR2_DCD;
            sreron |= SRER_MODEM;
            portp->flags |= ASYNC_CHECK_CD;
      } else {
            portp->flags &= ~ASYNC_CHECK_CD;
      }

/*
 *    Setup cd1400 enhanced modes if we can. In particular we want to
 *    handle as much of the flow control as possible automatically. As
 *    well as saving a few CPU cycles it will also greatly improve flow
 *    control reliability.
 */
      if (tiosp->c_iflag & IXON) {
            cor2 |= COR2_TXIBE;
            cor3 |= COR3_SCD12;
            if (tiosp->c_iflag & IXANY)
                  cor2 |= COR2_IXM;
      }

      if (tiosp->c_cflag & CRTSCTS) {
            cor2 |= COR2_CTSAE;
            mcor1 |= FIFO_RTSTHRESHOLD;
      }

/*
 *    All cd1400 register values calculated so go through and set
 *    them all up.
 */

#ifdef DEBUG
      printk("SETPORT: portnr=%d panelnr=%d brdnr=%d\n",
            portp->portnr, portp->panelnr, portp->brdnr);
      printk("    cor1=%x cor2=%x cor3=%x cor4=%x cor5=%x\n",
            cor1, cor2, cor3, cor4, cor5);
      printk("    mcor1=%x mcor2=%x rtpr=%x sreron=%x sreroff=%x\n",
            mcor1, mcor2, rtpr, sreron, sreroff);
      printk("    tcor=%x tbpr=%x rcor=%x rbpr=%x\n", clk, div, clk, div);
      printk("    schr1=%x schr2=%x schr3=%x schr4=%x\n",
            tiosp->c_cc[VSTART], tiosp->c_cc[VSTOP],
            tiosp->c_cc[VSTART], tiosp->c_cc[VSTOP]);
#endif

      spin_lock_irqsave(&brd_lock, flags);
      BRDENABLE(portp->brdnr, portp->pagenr);
      stl_cd1400setreg(portp, CAR, (portp->portnr & 0x3));
      srer = stl_cd1400getreg(portp, SRER);
      stl_cd1400setreg(portp, SRER, 0);
      if (stl_cd1400updatereg(portp, COR1, cor1))
            ccr = 1;
      if (stl_cd1400updatereg(portp, COR2, cor2))
            ccr = 1;
      if (stl_cd1400updatereg(portp, COR3, cor3))
            ccr = 1;
      if (ccr) {
            stl_cd1400ccrwait(portp);
            stl_cd1400setreg(portp, CCR, CCR_CORCHANGE);
      }
      stl_cd1400setreg(portp, COR4, cor4);
      stl_cd1400setreg(portp, COR5, cor5);
      stl_cd1400setreg(portp, MCOR1, mcor1);
      stl_cd1400setreg(portp, MCOR2, mcor2);
      if (baudrate > 0) {
            stl_cd1400setreg(portp, TCOR, clk);
            stl_cd1400setreg(portp, TBPR, div);
            stl_cd1400setreg(portp, RCOR, clk);
            stl_cd1400setreg(portp, RBPR, div);
      }
      stl_cd1400setreg(portp, SCHR1, tiosp->c_cc[VSTART]);
      stl_cd1400setreg(portp, SCHR2, tiosp->c_cc[VSTOP]);
      stl_cd1400setreg(portp, SCHR3, tiosp->c_cc[VSTART]);
      stl_cd1400setreg(portp, SCHR4, tiosp->c_cc[VSTOP]);
      stl_cd1400setreg(portp, RTPR, rtpr);
      mcor1 = stl_cd1400getreg(portp, MSVR1);
      if (mcor1 & MSVR1_DCD)
            portp->sigs |= TIOCM_CD;
      else
            portp->sigs &= ~TIOCM_CD;
      stl_cd1400setreg(portp, SRER, ((srer & ~sreroff) | sreron));
      BRDDISABLE(portp->brdnr);
      spin_unlock_irqrestore(&brd_lock, flags);
}

/*****************************************************************************/

/*
 *    Set the state of the DTR and RTS signals.
 */

static void stl_cd1400setsignals(stlport_t *portp, int dtr, int rts)
{
      unsigned char     msvr1, msvr2;
      unsigned long     flags;

#ifdef DEBUG
      printk("stl_cd1400setsignals(portp=%x,dtr=%d,rts=%d)\n",
            (int) portp, dtr, rts);
#endif

      msvr1 = 0;
      msvr2 = 0;
      if (dtr > 0)
            msvr1 = MSVR1_DTR;
      if (rts > 0)
            msvr2 = MSVR2_RTS;

      spin_lock_irqsave(&brd_lock, flags);
      BRDENABLE(portp->brdnr, portp->pagenr);
      stl_cd1400setreg(portp, CAR, (portp->portnr & 0x03));
      if (rts >= 0)
            stl_cd1400setreg(portp, MSVR2, msvr2);
      if (dtr >= 0)
            stl_cd1400setreg(portp, MSVR1, msvr1);
      BRDDISABLE(portp->brdnr);
      spin_unlock_irqrestore(&brd_lock, flags);
}

/*****************************************************************************/

/*
 *    Return the state of the signals.
 */

static int stl_cd1400getsignals(stlport_t *portp)
{
      unsigned char     msvr1, msvr2;
      unsigned long     flags;
      int         sigs;

#ifdef DEBUG
      printk("stl_cd1400getsignals(portp=%x)\n", (int) portp);
#endif

      spin_lock_irqsave(&brd_lock, flags);
      BRDENABLE(portp->brdnr, portp->pagenr);
      stl_cd1400setreg(portp, CAR, (portp->portnr & 0x03));
      msvr1 = stl_cd1400getreg(portp, MSVR1);
      msvr2 = stl_cd1400getreg(portp, MSVR2);
      BRDDISABLE(portp->brdnr);
      spin_unlock_irqrestore(&brd_lock, flags);

      sigs = 0;
      sigs |= (msvr1 & MSVR1_DCD) ? TIOCM_CD : 0;
      sigs |= (msvr1 & MSVR1_CTS) ? TIOCM_CTS : 0;
      sigs |= (msvr1 & MSVR1_DTR) ? TIOCM_DTR : 0;
      sigs |= (msvr2 & MSVR2_RTS) ? TIOCM_RTS : 0;
#if 0
      sigs |= (msvr1 & MSVR1_RI) ? TIOCM_RI : 0;
      sigs |= (msvr1 & MSVR1_DSR) ? TIOCM_DSR : 0;
#else
      sigs |= TIOCM_DSR;
#endif
      return sigs;
}

/*****************************************************************************/

/*
 *    Enable/Disable the Transmitter and/or Receiver.
 */

static void stl_cd1400enablerxtx(stlport_t *portp, int rx, int tx)
{
      unsigned char     ccr;
      unsigned long     flags;

#ifdef DEBUG
      printk("stl_cd1400enablerxtx(portp=%x,rx=%d,tx=%d)\n",
            (int) portp, rx, tx);
#endif
      ccr = 0;

      if (tx == 0)
            ccr |= CCR_TXDISABLE;
      else if (tx > 0)
            ccr |= CCR_TXENABLE;
      if (rx == 0)
            ccr |= CCR_RXDISABLE;
      else if (rx > 0)
            ccr |= CCR_RXENABLE;

      spin_lock_irqsave(&brd_lock, flags);
      BRDENABLE(portp->brdnr, portp->pagenr);
      stl_cd1400setreg(portp, CAR, (portp->portnr & 0x03));
      stl_cd1400ccrwait(portp);
      stl_cd1400setreg(portp, CCR, ccr);
      stl_cd1400ccrwait(portp);
      BRDDISABLE(portp->brdnr);
      spin_unlock_irqrestore(&brd_lock, flags);
}

/*****************************************************************************/

/*
 *    Start/stop the Transmitter and/or Receiver.
 */

static void stl_cd1400startrxtx(stlport_t *portp, int rx, int tx)
{
      unsigned char     sreron, sreroff;
      unsigned long     flags;

#ifdef DEBUG
      printk("stl_cd1400startrxtx(portp=%x,rx=%d,tx=%d)\n",
            (int) portp, rx, tx);
#endif

      sreron = 0;
      sreroff = 0;
      if (tx == 0)
            sreroff |= (SRER_TXDATA | SRER_TXEMPTY);
      else if (tx == 1)
            sreron |= SRER_TXDATA;
      else if (tx >= 2)
            sreron |= SRER_TXEMPTY;
      if (rx == 0)
            sreroff |= SRER_RXDATA;
      else if (rx > 0)
            sreron |= SRER_RXDATA;

      spin_lock_irqsave(&brd_lock, flags);
      BRDENABLE(portp->brdnr, portp->pagenr);
      stl_cd1400setreg(portp, CAR, (portp->portnr & 0x03));
      stl_cd1400setreg(portp, SRER,
            ((stl_cd1400getreg(portp, SRER) & ~sreroff) | sreron));
      BRDDISABLE(portp->brdnr);
      if (tx > 0)
            set_bit(ASYI_TXBUSY, &portp->istate);
      spin_unlock_irqrestore(&brd_lock, flags);
}

/*****************************************************************************/

/*
 *    Disable all interrupts from this port.
 */

static void stl_cd1400disableintrs(stlport_t *portp)
{
      unsigned long     flags;

#ifdef DEBUG
      printk("stl_cd1400disableintrs(portp=%x)\n", (int) portp);
#endif
      spin_lock_irqsave(&brd_lock, flags);
      BRDENABLE(portp->brdnr, portp->pagenr);
      stl_cd1400setreg(portp, CAR, (portp->portnr & 0x03));
      stl_cd1400setreg(portp, SRER, 0);
      BRDDISABLE(portp->brdnr);
      spin_unlock_irqrestore(&brd_lock, flags);
}

/*****************************************************************************/

static void stl_cd1400sendbreak(stlport_t *portp, int len)
{
      unsigned long     flags;

#ifdef DEBUG
      printk("stl_cd1400sendbreak(portp=%x,len=%d)\n", (int) portp, len);
#endif

      spin_lock_irqsave(&brd_lock, flags);
      BRDENABLE(portp->brdnr, portp->pagenr);
      stl_cd1400setreg(portp, CAR, (portp->portnr & 0x03));
      stl_cd1400setreg(portp, SRER,
            ((stl_cd1400getreg(portp, SRER) & ~SRER_TXDATA) |
            SRER_TXEMPTY));
      BRDDISABLE(portp->brdnr);
      portp->brklen = len;
      if (len == 1)
            portp->stats.txbreaks++;
      spin_unlock_irqrestore(&brd_lock, flags);
}

/*****************************************************************************/

/*
 *    Take flow control actions...
 */

static void stl_cd1400flowctrl(stlport_t *portp, int state)
{
      struct tty_struct *tty;
      unsigned long           flags;

#ifdef DEBUG
      printk("stl_cd1400flowctrl(portp=%x,state=%x)\n", (int) portp, state);
#endif

      if (portp == (stlport_t *) NULL)
            return;
      tty = portp->tty;
      if (tty == (struct tty_struct *) NULL)
            return;

      spin_lock_irqsave(&brd_lock, flags);
      BRDENABLE(portp->brdnr, portp->pagenr);
      stl_cd1400setreg(portp, CAR, (portp->portnr & 0x03));

      if (state) {
            if (tty->termios->c_iflag & IXOFF) {
                  stl_cd1400ccrwait(portp);
                  stl_cd1400setreg(portp, CCR, CCR_SENDSCHR1);
                  portp->stats.rxxon++;
                  stl_cd1400ccrwait(portp);
            }
/*
 *          Question: should we return RTS to what it was before? It may
 *          have been set by an ioctl... Suppose not, since if you have
 *          hardware flow control set then it is pretty silly to go and
 *          set the RTS line by hand.
 */
            if (tty->termios->c_cflag & CRTSCTS) {
                  stl_cd1400setreg(portp, MCOR1,
                        (stl_cd1400getreg(portp, MCOR1) |
                        FIFO_RTSTHRESHOLD));
                  stl_cd1400setreg(portp, MSVR2, MSVR2_RTS);
                  portp->stats.rxrtson++;
            }
      } else {
            if (tty->termios->c_iflag & IXOFF) {
                  stl_cd1400ccrwait(portp);
                  stl_cd1400setreg(portp, CCR, CCR_SENDSCHR2);
                  portp->stats.rxxoff++;
                  stl_cd1400ccrwait(portp);
            }
            if (tty->termios->c_cflag & CRTSCTS) {
                  stl_cd1400setreg(portp, MCOR1,
                        (stl_cd1400getreg(portp, MCOR1) & 0xf0));
                  stl_cd1400setreg(portp, MSVR2, 0);
                  portp->stats.rxrtsoff++;
            }
      }

      BRDDISABLE(portp->brdnr);
      spin_unlock_irqrestore(&brd_lock, flags);
}

/*****************************************************************************/

/*
 *    Send a flow control character...
 */

static void stl_cd1400sendflow(stlport_t *portp, int state)
{
      struct tty_struct *tty;
      unsigned long           flags;

#ifdef DEBUG
      printk("stl_cd1400sendflow(portp=%x,state=%x)\n", (int) portp, state);
#endif

      if (portp == (stlport_t *) NULL)
            return;
      tty = portp->tty;
      if (tty == (struct tty_struct *) NULL)
            return;

      spin_lock_irqsave(&brd_lock, flags);
      BRDENABLE(portp->brdnr, portp->pagenr);
      stl_cd1400setreg(portp, CAR, (portp->portnr & 0x03));
      if (state) {
            stl_cd1400ccrwait(portp);
            stl_cd1400setreg(portp, CCR, CCR_SENDSCHR1);
            portp->stats.rxxon++;
            stl_cd1400ccrwait(portp);
      } else {
            stl_cd1400ccrwait(portp);
            stl_cd1400setreg(portp, CCR, CCR_SENDSCHR2);
            portp->stats.rxxoff++;
            stl_cd1400ccrwait(portp);
      }
      BRDDISABLE(portp->brdnr);
      spin_unlock_irqrestore(&brd_lock, flags);
}

/*****************************************************************************/

static void stl_cd1400flush(stlport_t *portp)
{
      unsigned long     flags;

#ifdef DEBUG
      printk("stl_cd1400flush(portp=%x)\n", (int) portp);
#endif

      if (portp == (stlport_t *) NULL)
            return;

      spin_lock_irqsave(&brd_lock, flags);
      BRDENABLE(portp->brdnr, portp->pagenr);
      stl_cd1400setreg(portp, CAR, (portp->portnr & 0x03));
      stl_cd1400ccrwait(portp);
      stl_cd1400setreg(portp, CCR, CCR_TXFLUSHFIFO);
      stl_cd1400ccrwait(portp);
      portp->tx.tail = portp->tx.head;
      BRDDISABLE(portp->brdnr);
      spin_unlock_irqrestore(&brd_lock, flags);
}

/*****************************************************************************/

/*
 *    Return the current state of data flow on this port. This is only
 *    really interresting when determining if data has fully completed
 *    transmission or not... This is easy for the cd1400, it accurately
 *    maintains the busy port flag.
 */

static int stl_cd1400datastate(stlport_t *portp)
{
#ifdef DEBUG
      printk("stl_cd1400datastate(portp=%x)\n", (int) portp);
#endif

      if (portp == (stlport_t *) NULL)
            return 0;

      return test_bit(ASYI_TXBUSY, &portp->istate) ? 1 : 0;
}

/*****************************************************************************/

/*
 *    Interrupt service routine for cd1400 EasyIO boards.
 */

static void stl_cd1400eiointr(stlpanel_t *panelp, unsigned int iobase)
{
      unsigned char     svrtype;

#ifdef DEBUG
      printk("stl_cd1400eiointr(panelp=%x,iobase=%x)\n",
            (int) panelp, iobase);
#endif

      spin_lock(&brd_lock);
      outb(SVRR, iobase);
      svrtype = inb(iobase + EREG_DATA);
      if (panelp->nrports > 4) {
            outb((SVRR + 0x80), iobase);
            svrtype |= inb(iobase + EREG_DATA);
      }

      if (svrtype & SVRR_RX)
            stl_cd1400rxisr(panelp, iobase);
      else if (svrtype & SVRR_TX)
            stl_cd1400txisr(panelp, iobase);
      else if (svrtype & SVRR_MDM)
            stl_cd1400mdmisr(panelp, iobase);

      spin_unlock(&brd_lock);
}

/*****************************************************************************/

/*
 *    Interrupt service routine for cd1400 panels.
 */

static void stl_cd1400echintr(stlpanel_t *panelp, unsigned int iobase)
{
      unsigned char     svrtype;

#ifdef DEBUG
      printk("stl_cd1400echintr(panelp=%x,iobase=%x)\n", (int) panelp,
            iobase);
#endif

      outb(SVRR, iobase);
      svrtype = inb(iobase + EREG_DATA);
      outb((SVRR + 0x80), iobase);
      svrtype |= inb(iobase + EREG_DATA);
      if (svrtype & SVRR_RX)
            stl_cd1400rxisr(panelp, iobase);
      else if (svrtype & SVRR_TX)
            stl_cd1400txisr(panelp, iobase);
      else if (svrtype & SVRR_MDM)
            stl_cd1400mdmisr(panelp, iobase);
}


/*****************************************************************************/

/*
 *    Unfortunately we need to handle breaks in the TX data stream, since
 *    this is the only way to generate them on the cd1400.
 */

static inline int stl_cd1400breakisr(stlport_t *portp, int ioaddr)
{
      if (portp->brklen == 1) {
            outb((COR2 + portp->uartaddr), ioaddr);
            outb((inb(ioaddr + EREG_DATA) | COR2_ETC),
                  (ioaddr + EREG_DATA));
            outb((TDR + portp->uartaddr), ioaddr);
            outb(ETC_CMD, (ioaddr + EREG_DATA));
            outb(ETC_STARTBREAK, (ioaddr + EREG_DATA));
            outb((SRER + portp->uartaddr), ioaddr);
            outb((inb(ioaddr + EREG_DATA) & ~(SRER_TXDATA | SRER_TXEMPTY)),
                  (ioaddr + EREG_DATA));
            return 1;
      } else if (portp->brklen > 1) {
            outb((TDR + portp->uartaddr), ioaddr);
            outb(ETC_CMD, (ioaddr + EREG_DATA));
            outb(ETC_STOPBREAK, (ioaddr + EREG_DATA));
            portp->brklen = -1;
            return 1;
      } else {
            outb((COR2 + portp->uartaddr), ioaddr);
            outb((inb(ioaddr + EREG_DATA) & ~COR2_ETC),
                  (ioaddr + EREG_DATA));
            portp->brklen = 0;
      }
      return 0;
}

/*****************************************************************************/

/*
 *    Transmit interrupt handler. This has gotta be fast!  Handling TX
 *    chars is pretty simple, stuff as many as possible from the TX buffer
 *    into the cd1400 FIFO. Must also handle TX breaks here, since they
 *    are embedded as commands in the data stream. Oh no, had to use a goto!
 *    This could be optimized more, will do when I get time...
 *    In practice it is possible that interrupts are enabled but that the
 *    port has been hung up. Need to handle not having any TX buffer here,
 *    this is done by using the side effect that head and tail will also
 *    be NULL if the buffer has been freed.
 */

static void stl_cd1400txisr(stlpanel_t *panelp, int ioaddr)
{
      stlport_t   *portp;
      int         len, stlen;
      char        *head, *tail;
      unsigned char     ioack, srer;

#ifdef DEBUG
      printk("stl_cd1400txisr(panelp=%x,ioaddr=%x)\n", (int) panelp, ioaddr);
#endif

      ioack = inb(ioaddr + EREG_TXACK);
      if (((ioack & panelp->ackmask) != 0) ||
          ((ioack & ACK_TYPMASK) != ACK_TYPTX)) {
            printk("STALLION: bad TX interrupt ack value=%x\n", ioack);
            return;
      }
      portp = panelp->ports[(ioack >> 3)];

/*
 *    Unfortunately we need to handle breaks in the data stream, since
 *    this is the only way to generate them on the cd1400. Do it now if
 *    a break is to be sent.
 */
      if (portp->brklen != 0)
            if (stl_cd1400breakisr(portp, ioaddr))
                  goto stl_txalldone;

      head = portp->tx.head;
      tail = portp->tx.tail;
      len = (head >= tail) ? (head - tail) : (STL_TXBUFSIZE - (tail - head));
      if ((len == 0) || ((len < STL_TXBUFLOW) &&
          (test_bit(ASYI_TXLOW, &portp->istate) == 0))) {
            set_bit(ASYI_TXLOW, &portp->istate);
            schedule_work(&portp->tqueue);
      }

      if (len == 0) {
            outb((SRER + portp->uartaddr), ioaddr);
            srer = inb(ioaddr + EREG_DATA);
            if (srer & SRER_TXDATA) {
                  srer = (srer & ~SRER_TXDATA) | SRER_TXEMPTY;
            } else {
                  srer &= ~(SRER_TXDATA | SRER_TXEMPTY);
                  clear_bit(ASYI_TXBUSY, &portp->istate);
            }
            outb(srer, (ioaddr + EREG_DATA));
      } else {
            len = MIN(len, CD1400_TXFIFOSIZE);
            portp->stats.txtotal += len;
            stlen = MIN(len, ((portp->tx.buf + STL_TXBUFSIZE) - tail));
            outb((TDR + portp->uartaddr), ioaddr);
            outsb((ioaddr + EREG_DATA), tail, stlen);
            len -= stlen;
            tail += stlen;
            if (tail >= (portp->tx.buf + STL_TXBUFSIZE))
                  tail = portp->tx.buf;
            if (len > 0) {
                  outsb((ioaddr + EREG_DATA), tail, len);
                  tail += len;
            }
            portp->tx.tail = tail;
      }

stl_txalldone:
      outb((EOSRR + portp->uartaddr), ioaddr);
      outb(0, (ioaddr + EREG_DATA));
}

/*****************************************************************************/

/*
 *    Receive character interrupt handler. Determine if we have good chars
 *    or bad chars and then process appropriately. Good chars are easy
 *    just shove the lot into the RX buffer and set all status byte to 0.
 *    If a bad RX char then process as required. This routine needs to be
 *    fast!  In practice it is possible that we get an interrupt on a port
 *    that is closed. This can happen on hangups - since they completely
 *    shutdown a port not in user context. Need to handle this case.
 */

static void stl_cd1400rxisr(stlpanel_t *panelp, int ioaddr)
{
      stlport_t         *portp;
      struct tty_struct *tty;
      unsigned int            ioack, len, buflen;
      unsigned char           status;
      char              ch;

#ifdef DEBUG
      printk("stl_cd1400rxisr(panelp=%x,ioaddr=%x)\n", (int) panelp, ioaddr);
#endif

      ioack = inb(ioaddr + EREG_RXACK);
      if ((ioack & panelp->ackmask) != 0) {
            printk("STALLION: bad RX interrupt ack value=%x\n", ioack);
            return;
      }
      portp = panelp->ports[(ioack >> 3)];
      tty = portp->tty;

      if ((ioack & ACK_TYPMASK) == ACK_TYPRXGOOD) {
            outb((RDCR + portp->uartaddr), ioaddr);
            len = inb(ioaddr + EREG_DATA);
            if (tty == NULL || (buflen = tty_buffer_request_room(tty, len)) == 0) {
                  len = MIN(len, sizeof(stl_unwanted));
                  outb((RDSR + portp->uartaddr), ioaddr);
                  insb((ioaddr + EREG_DATA), &stl_unwanted[0], len);
                  portp->stats.rxlost += len;
                  portp->stats.rxtotal += len;
            } else {
                  len = MIN(len, buflen);
                  if (len > 0) {
                        unsigned char *ptr;
                        outb((RDSR + portp->uartaddr), ioaddr);
                        tty_prepare_flip_string(tty, &ptr, len);
                        insb((ioaddr + EREG_DATA), ptr, len);
                        tty_schedule_flip(tty);
                        portp->stats.rxtotal += len;
                  }
            }
      } else if ((ioack & ACK_TYPMASK) == ACK_TYPRXBAD) {
            outb((RDSR + portp->uartaddr), ioaddr);
            status = inb(ioaddr + EREG_DATA);
            ch = inb(ioaddr + EREG_DATA);
            if (status & ST_PARITY)
                  portp->stats.rxparity++;
            if (status & ST_FRAMING)
                  portp->stats.rxframing++;
            if (status & ST_OVERRUN)
                  portp->stats.rxoverrun++;
            if (status & ST_BREAK)
                  portp->stats.rxbreaks++;
            if (status & ST_SCHARMASK) {
                  if ((status & ST_SCHARMASK) == ST_SCHAR1)
                        portp->stats.txxon++;
                  if ((status & ST_SCHARMASK) == ST_SCHAR2)
                        portp->stats.txxoff++;
                  goto stl_rxalldone;
            }
            if (tty != NULL && (portp->rxignoremsk & status) == 0) {
                  if (portp->rxmarkmsk & status) {
                        if (status & ST_BREAK) {
                              status = TTY_BREAK;
                              if (portp->flags & ASYNC_SAK) {
                                    do_SAK(tty);
                                    BRDENABLE(portp->brdnr, portp->pagenr);
                              }
                        } else if (status & ST_PARITY) {
                              status = TTY_PARITY;
                        } else if (status & ST_FRAMING) {
                              status = TTY_FRAME;
                        } else if(status & ST_OVERRUN) {
                              status = TTY_OVERRUN;
                        } else {
                              status = 0;
                        }
                  } else {
                        status = 0;
                  }
                  tty_insert_flip_char(tty, ch, status);
                  tty_schedule_flip(tty);
            }
      } else {
            printk("STALLION: bad RX interrupt ack value=%x\n", ioack);
            return;
      }

stl_rxalldone:
      outb((EOSRR + portp->uartaddr), ioaddr);
      outb(0, (ioaddr + EREG_DATA));
}

/*****************************************************************************/

/*
 *    Modem interrupt handler. The is called when the modem signal line
 *    (DCD) has changed state. Leave most of the work to the off-level
 *    processing routine.
 */

static void stl_cd1400mdmisr(stlpanel_t *panelp, int ioaddr)
{
      stlport_t   *portp;
      unsigned int      ioack;
      unsigned char     misr;

#ifdef DEBUG
      printk("stl_cd1400mdmisr(panelp=%x)\n", (int) panelp);
#endif

      ioack = inb(ioaddr + EREG_MDACK);
      if (((ioack & panelp->ackmask) != 0) ||
          ((ioack & ACK_TYPMASK) != ACK_TYPMDM)) {
            printk("STALLION: bad MODEM interrupt ack value=%x\n", ioack);
            return;
      }
      portp = panelp->ports[(ioack >> 3)];

      outb((MISR + portp->uartaddr), ioaddr);
      misr = inb(ioaddr + EREG_DATA);
      if (misr & MISR_DCD) {
            set_bit(ASYI_DCDCHANGE, &portp->istate);
            schedule_work(&portp->tqueue);
            portp->stats.modem++;
      }

      outb((EOSRR + portp->uartaddr), ioaddr);
      outb(0, (ioaddr + EREG_DATA));
}

/*****************************************************************************/
/*                      SC26198 HARDWARE FUNCTIONS                           */
/*****************************************************************************/

/*
 *    These functions get/set/update the registers of the sc26198 UARTs.
 *    Access to the sc26198 registers is via an address/data io port pair.
 *    (Maybe should make this inline...)
 */

static int stl_sc26198getreg(stlport_t *portp, int regnr)
{
      outb((regnr | portp->uartaddr), (portp->ioaddr + XP_ADDR));
      return inb(portp->ioaddr + XP_DATA);
}

static void stl_sc26198setreg(stlport_t *portp, int regnr, int value)
{
      outb((regnr | portp->uartaddr), (portp->ioaddr + XP_ADDR));
      outb(value, (portp->ioaddr + XP_DATA));
}

static int stl_sc26198updatereg(stlport_t *portp, int regnr, int value)
{
      outb((regnr | portp->uartaddr), (portp->ioaddr + XP_ADDR));
      if (inb(portp->ioaddr + XP_DATA) != value) {
            outb(value, (portp->ioaddr + XP_DATA));
            return 1;
      }
      return 0;
}

/*****************************************************************************/

/*
 *    Functions to get and set the sc26198 global registers.
 */

static int stl_sc26198getglobreg(stlport_t *portp, int regnr)
{
      outb(regnr, (portp->ioaddr + XP_ADDR));
      return inb(portp->ioaddr + XP_DATA);
}

#if 0
static void stl_sc26198setglobreg(stlport_t *portp, int regnr, int value)
{
      outb(regnr, (portp->ioaddr + XP_ADDR));
      outb(value, (portp->ioaddr + XP_DATA));
}
#endif

/*****************************************************************************/

/*
 *    Inbitialize the UARTs in a panel. We don't care what sort of board
 *    these ports are on - since the port io registers are almost
 *    identical when dealing with ports.
 */

static int stl_sc26198panelinit(stlbrd_t *brdp, stlpanel_t *panelp)
{
      int   chipmask, i;
      int   nrchips, ioaddr;

#ifdef DEBUG
      printk("stl_sc26198panelinit(brdp=%x,panelp=%x)\n",
            (int) brdp, (int) panelp);
#endif

      BRDENABLE(panelp->brdnr, panelp->pagenr);

/*
 *    Check that each chip is present and started up OK.
 */
      chipmask = 0;
      nrchips = (panelp->nrports + 4) / SC26198_PORTS;
      if (brdp->brdtype == BRD_ECHPCI)
            outb(panelp->pagenr, brdp->ioctrl);

      for (i = 0; (i < nrchips); i++) {
            ioaddr = panelp->iobase + (i * 4); 
            outb(SCCR, (ioaddr + XP_ADDR));
            outb(CR_RESETALL, (ioaddr + XP_DATA));
            outb(TSTR, (ioaddr + XP_ADDR));
            if (inb(ioaddr + XP_DATA) != 0) {
                  printk("STALLION: sc26198 not responding, "
                        "brd=%d panel=%d chip=%d\n",
                        panelp->brdnr, panelp->panelnr, i);
                  continue;
            }
            chipmask |= (0x1 << i);
            outb(GCCR, (ioaddr + XP_ADDR));
            outb(GCCR_IVRTYPCHANACK, (ioaddr + XP_DATA));
            outb(WDTRCR, (ioaddr + XP_ADDR));
            outb(0xff, (ioaddr + XP_DATA));
      }

      BRDDISABLE(panelp->brdnr);
      return chipmask;
}

/*****************************************************************************/

/*
 *    Initialize hardware specific port registers.
 */

static void stl_sc26198portinit(stlbrd_t *brdp, stlpanel_t *panelp, stlport_t *portp)
{
#ifdef DEBUG
      printk("stl_sc26198portinit(brdp=%x,panelp=%x,portp=%x)\n",
            (int) brdp, (int) panelp, (int) portp);
#endif

      if ((brdp == (stlbrd_t *) NULL) || (panelp == (stlpanel_t *) NULL) ||
          (portp == (stlport_t *) NULL))
            return;

      portp->ioaddr = panelp->iobase + ((portp->portnr < 8) ? 0 : 4);
      portp->uartaddr = (portp->portnr & 0x07) << 4;
      portp->pagenr = panelp->pagenr;
      portp->hwid = 0x1;

      BRDENABLE(portp->brdnr, portp->pagenr);
      stl_sc26198setreg(portp, IOPCR, IOPCR_SETSIGS);
      BRDDISABLE(portp->brdnr);
}

/*****************************************************************************/

/*
 *    Set up the sc26198 registers for a port based on the termios port
 *    settings.
 */

static void stl_sc26198setport(stlport_t *portp, struct termios *tiosp)
{
      stlbrd_t    *brdp;
      unsigned long     flags;
      unsigned int      baudrate;
      unsigned char     mr0, mr1, mr2, clk;
      unsigned char     imron, imroff, iopr, ipr;

      mr0 = 0;
      mr1 = 0;
      mr2 = 0;
      clk = 0;
      iopr = 0;
      imron = 0;
      imroff = 0;

      brdp = stl_brds[portp->brdnr];
      if (brdp == (stlbrd_t *) NULL)
            return;

/*
 *    Set up the RX char ignore mask with those RX error types we
 *    can ignore.
 */
      portp->rxignoremsk = 0;
      if (tiosp->c_iflag & IGNPAR)
            portp->rxignoremsk |= (SR_RXPARITY | SR_RXFRAMING |
                  SR_RXOVERRUN);
      if (tiosp->c_iflag & IGNBRK)
            portp->rxignoremsk |= SR_RXBREAK;

      portp->rxmarkmsk = SR_RXOVERRUN;
      if (tiosp->c_iflag & (INPCK | PARMRK))
            portp->rxmarkmsk |= (SR_RXPARITY | SR_RXFRAMING);
      if (tiosp->c_iflag & BRKINT)
            portp->rxmarkmsk |= SR_RXBREAK;

/*
 *    Go through the char size, parity and stop bits and set all the
 *    option register appropriately.
 */
      switch (tiosp->c_cflag & CSIZE) {
      case CS5:
            mr1 |= MR1_CS5;
            break;
      case CS6:
            mr1 |= MR1_CS6;
            break;
      case CS7:
            mr1 |= MR1_CS7;
            break;
      default:
            mr1 |= MR1_CS8;
            break;
      }

      if (tiosp->c_cflag & CSTOPB)
            mr2 |= MR2_STOP2;
      else
            mr2 |= MR2_STOP1;

      if (tiosp->c_cflag & PARENB) {
            if (tiosp->c_cflag & PARODD)
                  mr1 |= (MR1_PARENB | MR1_PARODD);
            else
                  mr1 |= (MR1_PARENB | MR1_PAREVEN);
      } else {
            mr1 |= MR1_PARNONE;
      }

      mr1 |= MR1_ERRBLOCK;

/*
 *    Set the RX FIFO threshold at 8 chars. This gives a bit of breathing
 *    space for hardware flow control and the like. This should be set to
 *    VMIN.
 */
      mr2 |= MR2_RXFIFOHALF;

/*
 *    Calculate the baud rate timers. For now we will just assume that
 *    the input and output baud are the same. The sc26198 has a fixed
 *    baud rate table, so only discrete baud rates possible.
 */
      baudrate = tiosp->c_cflag & CBAUD;
      if (baudrate & CBAUDEX) {
            baudrate &= ~CBAUDEX;
            if ((baudrate < 1) || (baudrate > 4))
                  tiosp->c_cflag &= ~CBAUDEX;
            else
                  baudrate += 15;
      }
      baudrate = stl_baudrates[baudrate];
      if ((tiosp->c_cflag & CBAUD) == B38400) {
            if ((portp->flags & ASYNC_SPD_MASK) == ASYNC_SPD_HI)
                  baudrate = 57600;
            else if ((portp->flags & ASYNC_SPD_MASK) == ASYNC_SPD_VHI)
                  baudrate = 115200;
            else if ((portp->flags & ASYNC_SPD_MASK) == ASYNC_SPD_SHI)
                  baudrate = 230400;
            else if ((portp->flags & ASYNC_SPD_MASK) == ASYNC_SPD_WARP)
                  baudrate = 460800;
            else if ((portp->flags & ASYNC_SPD_MASK) == ASYNC_SPD_CUST)
                  baudrate = (portp->baud_base / portp->custom_divisor);
      }
      if (baudrate > STL_SC26198MAXBAUD)
            baudrate = STL_SC26198MAXBAUD;

      if (baudrate > 0) {
            for (clk = 0; (clk < SC26198_NRBAUDS); clk++) {
                  if (baudrate <= sc26198_baudtable[clk])
                        break;
            }
      }

/*
 *    Check what form of modem signaling is required and set it up.
 */
      if (tiosp->c_cflag & CLOCAL) {
            portp->flags &= ~ASYNC_CHECK_CD;
      } else {
            iopr |= IOPR_DCDCOS;
            imron |= IR_IOPORT;
            portp->flags |= ASYNC_CHECK_CD;
      }

/*
 *    Setup sc26198 enhanced modes if we can. In particular we want to
 *    handle as much of the flow control as possible automatically. As
 *    well as saving a few CPU cycles it will also greatly improve flow
 *    control reliability.
 */
      if (tiosp->c_iflag & IXON) {
            mr0 |= MR0_SWFTX | MR0_SWFT;
            imron |= IR_XONXOFF;
      } else {
            imroff |= IR_XONXOFF;
      }
      if (tiosp->c_iflag & IXOFF)
            mr0 |= MR0_SWFRX;

      if (tiosp->c_cflag & CRTSCTS) {
            mr2 |= MR2_AUTOCTS;
            mr1 |= MR1_AUTORTS;
      }

/*
 *    All sc26198 register values calculated so go through and set
 *    them all up.
 */

#ifdef DEBUG
      printk("SETPORT: portnr=%d panelnr=%d brdnr=%d\n",
            portp->portnr, portp->panelnr, portp->brdnr);
      printk("    mr0=%x mr1=%x mr2=%x clk=%x\n", mr0, mr1, mr2, clk);
      printk("    iopr=%x imron=%x imroff=%x\n", iopr, imron, imroff);
      printk("    schr1=%x schr2=%x schr3=%x schr4=%x\n",
            tiosp->c_cc[VSTART], tiosp->c_cc[VSTOP],
            tiosp->c_cc[VSTART], tiosp->c_cc[VSTOP]);
#endif

      spin_lock_irqsave(&brd_lock, flags);
      BRDENABLE(portp->brdnr, portp->pagenr);
      stl_sc26198setreg(portp, IMR, 0);
      stl_sc26198updatereg(portp, MR0, mr0);
      stl_sc26198updatereg(portp, MR1, mr1);
      stl_sc26198setreg(portp, SCCR, CR_RXERRBLOCK);
      stl_sc26198updatereg(portp, MR2, mr2);
      stl_sc26198updatereg(portp, IOPIOR,
            ((stl_sc26198getreg(portp, IOPIOR) & ~IPR_CHANGEMASK) | iopr));

      if (baudrate > 0) {
            stl_sc26198setreg(portp, TXCSR, clk);
            stl_sc26198setreg(portp, RXCSR, clk);
      }

      stl_sc26198setreg(portp, XONCR, tiosp->c_cc[VSTART]);
      stl_sc26198setreg(portp, XOFFCR, tiosp->c_cc[VSTOP]);

      ipr = stl_sc26198getreg(portp, IPR);
      if (ipr & IPR_DCD)
            portp->sigs &= ~TIOCM_CD;
      else
            portp->sigs |= TIOCM_CD;

      portp->imr = (portp->imr & ~imroff) | imron;
      stl_sc26198setreg(portp, IMR, portp->imr);
      BRDDISABLE(portp->brdnr);
      spin_unlock_irqrestore(&brd_lock, flags);
}

/*****************************************************************************/

/*
 *    Set the state of the DTR and RTS signals.
 */

static void stl_sc26198setsignals(stlport_t *portp, int dtr, int rts)
{
      unsigned char     iopioron, iopioroff;
      unsigned long     flags;

#ifdef DEBUG
      printk("stl_sc26198setsignals(portp=%x,dtr=%d,rts=%d)\n",
            (int) portp, dtr, rts);
#endif

      iopioron = 0;
      iopioroff = 0;
      if (dtr == 0)
            iopioroff |= IPR_DTR;
      else if (dtr > 0)
            iopioron |= IPR_DTR;
      if (rts == 0)
            iopioroff |= IPR_RTS;
      else if (rts > 0)
            iopioron |= IPR_RTS;

      spin_lock_irqsave(&brd_lock, flags);
      BRDENABLE(portp->brdnr, portp->pagenr);
      stl_sc26198setreg(portp, IOPIOR,
            ((stl_sc26198getreg(portp, IOPIOR) & ~iopioroff) | iopioron));
      BRDDISABLE(portp->brdnr);
      spin_unlock_irqrestore(&brd_lock, flags);
}

/*****************************************************************************/

/*
 *    Return the state of the signals.
 */

static int stl_sc26198getsignals(stlport_t *portp)
{
      unsigned char     ipr;
      unsigned long     flags;
      int         sigs;

#ifdef DEBUG
      printk("stl_sc26198getsignals(portp=%x)\n", (int) portp);
#endif

      spin_lock_irqsave(&brd_lock, flags);
      BRDENABLE(portp->brdnr, portp->pagenr);
      ipr = stl_sc26198getreg(portp, IPR);
      BRDDISABLE(portp->brdnr);
      spin_unlock_irqrestore(&brd_lock, flags);

      sigs = 0;
      sigs |= (ipr & IPR_DCD) ? 0 : TIOCM_CD;
      sigs |= (ipr & IPR_CTS) ? 0 : TIOCM_CTS;
      sigs |= (ipr & IPR_DTR) ? 0: TIOCM_DTR;
      sigs |= (ipr & IPR_RTS) ? 0: TIOCM_RTS;
      sigs |= TIOCM_DSR;
      return sigs;
}

/*****************************************************************************/

/*
 *    Enable/Disable the Transmitter and/or Receiver.
 */

static void stl_sc26198enablerxtx(stlport_t *portp, int rx, int tx)
{
      unsigned char     ccr;
      unsigned long     flags;

#ifdef DEBUG
      printk("stl_sc26198enablerxtx(portp=%x,rx=%d,tx=%d)\n",
            (int) portp, rx, tx);
#endif

      ccr = portp->crenable;
      if (tx == 0)
            ccr &= ~CR_TXENABLE;
      else if (tx > 0)
            ccr |= CR_TXENABLE;
      if (rx == 0)
            ccr &= ~CR_RXENABLE;
      else if (rx > 0)
            ccr |= CR_RXENABLE;

      spin_lock_irqsave(&brd_lock, flags);
      BRDENABLE(portp->brdnr, portp->pagenr);
      stl_sc26198setreg(portp, SCCR, ccr);
      BRDDISABLE(portp->brdnr);
      portp->crenable = ccr;
      spin_unlock_irqrestore(&brd_lock, flags);
}

/*****************************************************************************/

/*
 *    Start/stop the Transmitter and/or Receiver.
 */

static void stl_sc26198startrxtx(stlport_t *portp, int rx, int tx)
{
      unsigned char     imr;
      unsigned long     flags;

#ifdef DEBUG
      printk("stl_sc26198startrxtx(portp=%x,rx=%d,tx=%d)\n",
            (int) portp, rx, tx);
#endif

      imr = portp->imr;
      if (tx == 0)
            imr &= ~IR_TXRDY;
      else if (tx == 1)
            imr |= IR_TXRDY;
      if (rx == 0)
            imr &= ~(IR_RXRDY | IR_RXBREAK | IR_RXWATCHDOG);
      else if (rx > 0)
            imr |= IR_RXRDY | IR_RXBREAK | IR_RXWATCHDOG;

      spin_lock_irqsave(&brd_lock, flags);
      BRDENABLE(portp->brdnr, portp->pagenr);
      stl_sc26198setreg(portp, IMR, imr);
      BRDDISABLE(portp->brdnr);
      portp->imr = imr;
      if (tx > 0)
            set_bit(ASYI_TXBUSY, &portp->istate);
      spin_unlock_irqrestore(&brd_lock, flags);
}

/*****************************************************************************/

/*
 *    Disable all interrupts from this port.
 */

static void stl_sc26198disableintrs(stlport_t *portp)
{
      unsigned long     flags;

#ifdef DEBUG
      printk("stl_sc26198disableintrs(portp=%x)\n", (int) portp);
#endif

      spin_lock_irqsave(&brd_lock, flags);
      BRDENABLE(portp->brdnr, portp->pagenr);
      portp->imr = 0;
      stl_sc26198setreg(portp, IMR, 0);
      BRDDISABLE(portp->brdnr);
      spin_unlock_irqrestore(&brd_lock, flags);
}

/*****************************************************************************/

static void stl_sc26198sendbreak(stlport_t *portp, int len)
{
      unsigned long     flags;

#ifdef DEBUG
      printk("stl_sc26198sendbreak(portp=%x,len=%d)\n", (int) portp, len);
#endif

      spin_lock_irqsave(&brd_lock, flags);
      BRDENABLE(portp->brdnr, portp->pagenr);
      if (len == 1) {
            stl_sc26198setreg(portp, SCCR, CR_TXSTARTBREAK);
            portp->stats.txbreaks++;
      } else {
            stl_sc26198setreg(portp, SCCR, CR_TXSTOPBREAK);
      }
      BRDDISABLE(portp->brdnr);
      spin_unlock_irqrestore(&brd_lock, flags);
}

/*****************************************************************************/

/*
 *    Take flow control actions...
 */

static void stl_sc26198flowctrl(stlport_t *portp, int state)
{
      struct tty_struct *tty;
      unsigned long           flags;
      unsigned char           mr0;

#ifdef DEBUG
      printk("stl_sc26198flowctrl(portp=%x,state=%x)\n", (int) portp, state);
#endif

      if (portp == (stlport_t *) NULL)
            return;
      tty = portp->tty;
      if (tty == (struct tty_struct *) NULL)
            return;

      spin_lock_irqsave(&brd_lock, flags);
      BRDENABLE(portp->brdnr, portp->pagenr);

      if (state) {
            if (tty->termios->c_iflag & IXOFF) {
                  mr0 = stl_sc26198getreg(portp, MR0);
                  stl_sc26198setreg(portp, MR0, (mr0 & ~MR0_SWFRXTX));
                  stl_sc26198setreg(portp, SCCR, CR_TXSENDXON);
                  mr0 |= MR0_SWFRX;
                  portp->stats.rxxon++;
                  stl_sc26198wait(portp);
                  stl_sc26198setreg(portp, MR0, mr0);
            }
/*
 *          Question: should we return RTS to what it was before? It may
 *          have been set by an ioctl... Suppose not, since if you have
 *          hardware flow control set then it is pretty silly to go and
 *          set the RTS line by hand.
 */
            if (tty->termios->c_cflag & CRTSCTS) {
                  stl_sc26198setreg(portp, MR1,
                        (stl_sc26198getreg(portp, MR1) | MR1_AUTORTS));
                  stl_sc26198setreg(portp, IOPIOR,
                        (stl_sc26198getreg(portp, IOPIOR) | IOPR_RTS));
                  portp->stats.rxrtson++;
            }
      } else {
            if (tty->termios->c_iflag & IXOFF) {
                  mr0 = stl_sc26198getreg(portp, MR0);
                  stl_sc26198setreg(portp, MR0, (mr0 & ~MR0_SWFRXTX));
                  stl_sc26198setreg(portp, SCCR, CR_TXSENDXOFF);
                  mr0 &= ~MR0_SWFRX;
                  portp->stats.rxxoff++;
                  stl_sc26198wait(portp);
                  stl_sc26198setreg(portp, MR0, mr0);
            }
            if (tty->termios->c_cflag & CRTSCTS) {
                  stl_sc26198setreg(portp, MR1,
                        (stl_sc26198getreg(portp, MR1) & ~MR1_AUTORTS));
                  stl_sc26198setreg(portp, IOPIOR,
                        (stl_sc26198getreg(portp, IOPIOR) & ~IOPR_RTS));
                  portp->stats.rxrtsoff++;
            }
      }

      BRDDISABLE(portp->brdnr);
      spin_unlock_irqrestore(&brd_lock, flags);
}

/*****************************************************************************/

/*
 *    Send a flow control character.
 */

static void stl_sc26198sendflow(stlport_t *portp, int state)
{
      struct tty_struct *tty;
      unsigned long           flags;
      unsigned char           mr0;

#ifdef DEBUG
      printk("stl_sc26198sendflow(portp=%x,state=%x)\n", (int) portp, state);
#endif

      if (portp == (stlport_t *) NULL)
            return;
      tty = portp->tty;
      if (tty == (struct tty_struct *) NULL)
            return;

      spin_lock_irqsave(&brd_lock, flags);
      BRDENABLE(portp->brdnr, portp->pagenr);
      if (state) {
            mr0 = stl_sc26198getreg(portp, MR0);
            stl_sc26198setreg(portp, MR0, (mr0 & ~MR0_SWFRXTX));
            stl_sc26198setreg(portp, SCCR, CR_TXSENDXON);
            mr0 |= MR0_SWFRX;
            portp->stats.rxxon++;
            stl_sc26198wait(portp);
            stl_sc26198setreg(portp, MR0, mr0);
      } else {
            mr0 = stl_sc26198getreg(portp, MR0);
            stl_sc26198setreg(portp, MR0, (mr0 & ~MR0_SWFRXTX));
            stl_sc26198setreg(portp, SCCR, CR_TXSENDXOFF);
            mr0 &= ~MR0_SWFRX;
            portp->stats.rxxoff++;
            stl_sc26198wait(portp);
            stl_sc26198setreg(portp, MR0, mr0);
      }
      BRDDISABLE(portp->brdnr);
      spin_unlock_irqrestore(&brd_lock, flags);
}

/*****************************************************************************/

static void stl_sc26198flush(stlport_t *portp)
{
      unsigned long     flags;

#ifdef DEBUG
      printk("stl_sc26198flush(portp=%x)\n", (int) portp);
#endif

      if (portp == (stlport_t *) NULL)
            return;

      spin_lock_irqsave(&brd_lock, flags);
      BRDENABLE(portp->brdnr, portp->pagenr);
      stl_sc26198setreg(portp, SCCR, CR_TXRESET);
      stl_sc26198setreg(portp, SCCR, portp->crenable);
      BRDDISABLE(portp->brdnr);
      portp->tx.tail = portp->tx.head;
      spin_unlock_irqrestore(&brd_lock, flags);
}

/*****************************************************************************/

/*
 *    Return the current state of data flow on this port. This is only
 *    really interresting when determining if data has fully completed
 *    transmission or not... The sc26198 interrupt scheme cannot
 *    determine when all data has actually drained, so we need to
 *    check the port statusy register to be sure.
 */

static int stl_sc26198datastate(stlport_t *portp)
{
      unsigned long     flags;
      unsigned char     sr;

#ifdef DEBUG
      printk("stl_sc26198datastate(portp=%x)\n", (int) portp);
#endif

      if (portp == (stlport_t *) NULL)
            return 0;
      if (test_bit(ASYI_TXBUSY, &portp->istate))
            return 1;

      spin_lock_irqsave(&brd_lock, flags);
      BRDENABLE(portp->brdnr, portp->pagenr);
      sr = stl_sc26198getreg(portp, SR);
      BRDDISABLE(portp->brdnr);
      spin_unlock_irqrestore(&brd_lock, flags);

      return (sr & SR_TXEMPTY) ? 0 : 1;
}

/*****************************************************************************/

/*
 *    Delay for a small amount of time, to give the sc26198 a chance
 *    to process a command...
 */

static void stl_sc26198wait(stlport_t *portp)
{
      int   i;

#ifdef DEBUG
      printk("stl_sc26198wait(portp=%x)\n", (int) portp);
#endif

      if (portp == (stlport_t *) NULL)
            return;

      for (i = 0; (i < 20); i++)
            stl_sc26198getglobreg(portp, TSTR);
}

/*****************************************************************************/

/*
 *    If we are TX flow controlled and in IXANY mode then we may
 *    need to unflow control here. We gotta do this because of the
 *    automatic flow control modes of the sc26198.
 */

static inline void stl_sc26198txunflow(stlport_t *portp, struct tty_struct *tty)
{
      unsigned char     mr0;

      mr0 = stl_sc26198getreg(portp, MR0);
      stl_sc26198setreg(portp, MR0, (mr0 & ~MR0_SWFRXTX));
      stl_sc26198setreg(portp, SCCR, CR_HOSTXON);
      stl_sc26198wait(portp);
      stl_sc26198setreg(portp, MR0, mr0);
      clear_bit(ASYI_TXFLOWED, &portp->istate);
}

/*****************************************************************************/

/*
 *    Interrupt service routine for sc26198 panels.
 */

static void stl_sc26198intr(stlpanel_t *panelp, unsigned int iobase)
{
      stlport_t   *portp;
      unsigned int      iack;

      spin_lock(&brd_lock);

/* 
 *    Work around bug in sc26198 chip... Cannot have A6 address
 *    line of UART high, else iack will be returned as 0.
 */
      outb(0, (iobase + 1));

      iack = inb(iobase + XP_IACK);
      portp = panelp->ports[(iack & IVR_CHANMASK) + ((iobase & 0x4) << 1)];

      if (iack & IVR_RXDATA)
            stl_sc26198rxisr(portp, iack);
      else if (iack & IVR_TXDATA)
            stl_sc26198txisr(portp);
      else
            stl_sc26198otherisr(portp, iack);

      spin_unlock(&brd_lock);
}

/*****************************************************************************/

/*
 *    Transmit interrupt handler. This has gotta be fast!  Handling TX
 *    chars is pretty simple, stuff as many as possible from the TX buffer
 *    into the sc26198 FIFO.
 *    In practice it is possible that interrupts are enabled but that the
 *    port has been hung up. Need to handle not having any TX buffer here,
 *    this is done by using the side effect that head and tail will also
 *    be NULL if the buffer has been freed.
 */

static void stl_sc26198txisr(stlport_t *portp)
{
      unsigned int      ioaddr;
      unsigned char     mr0;
      int         len, stlen;
      char        *head, *tail;

#ifdef DEBUG
      printk("stl_sc26198txisr(portp=%x)\n", (int) portp);
#endif

      ioaddr = portp->ioaddr;
      head = portp->tx.head;
      tail = portp->tx.tail;
      len = (head >= tail) ? (head - tail) : (STL_TXBUFSIZE - (tail - head));
      if ((len == 0) || ((len < STL_TXBUFLOW) &&
          (test_bit(ASYI_TXLOW, &portp->istate) == 0))) {
            set_bit(ASYI_TXLOW, &portp->istate);
            schedule_work(&portp->tqueue); 
      }

      if (len == 0) {
            outb((MR0 | portp->uartaddr), (ioaddr + XP_ADDR));
            mr0 = inb(ioaddr + XP_DATA);
            if ((mr0 & MR0_TXMASK) == MR0_TXEMPTY) {
                  portp->imr &= ~IR_TXRDY;
                  outb((IMR | portp->uartaddr), (ioaddr + XP_ADDR));
                  outb(portp->imr, (ioaddr + XP_DATA));
                  clear_bit(ASYI_TXBUSY, &portp->istate);
            } else {
                  mr0 |= ((mr0 & ~MR0_TXMASK) | MR0_TXEMPTY);
                  outb(mr0, (ioaddr + XP_DATA));
            }
      } else {
            len = MIN(len, SC26198_TXFIFOSIZE);
            portp->stats.txtotal += len;
            stlen = MIN(len, ((portp->tx.buf + STL_TXBUFSIZE) - tail));
            outb(GTXFIFO, (ioaddr + XP_ADDR));
            outsb((ioaddr + XP_DATA), tail, stlen);
            len -= stlen;
            tail += stlen;
            if (tail >= (portp->tx.buf + STL_TXBUFSIZE))
                  tail = portp->tx.buf;
            if (len > 0) {
                  outsb((ioaddr + XP_DATA), tail, len);
                  tail += len;
            }
            portp->tx.tail = tail;
      }
}

/*****************************************************************************/

/*
 *    Receive character interrupt handler. Determine if we have good chars
 *    or bad chars and then process appropriately. Good chars are easy
 *    just shove the lot into the RX buffer and set all status byte to 0.
 *    If a bad RX char then process as required. This routine needs to be
 *    fast!  In practice it is possible that we get an interrupt on a port
 *    that is closed. This can happen on hangups - since they completely
 *    shutdown a port not in user context. Need to handle this case.
 */

static void stl_sc26198rxisr(stlport_t *portp, unsigned int iack)
{
      struct tty_struct *tty;
      unsigned int            len, buflen, ioaddr;

#ifdef DEBUG
      printk("stl_sc26198rxisr(portp=%x,iack=%x)\n", (int) portp, iack);
#endif

      tty = portp->tty;
      ioaddr = portp->ioaddr;
      outb(GIBCR, (ioaddr + XP_ADDR));
      len = inb(ioaddr + XP_DATA) + 1;

      if ((iack & IVR_TYPEMASK) == IVR_RXDATA) {
            if (tty == NULL || (buflen = tty_buffer_request_room(tty, len)) == 0) {
                  len = MIN(len, sizeof(stl_unwanted));
                  outb(GRXFIFO, (ioaddr + XP_ADDR));
                  insb((ioaddr + XP_DATA), &stl_unwanted[0], len);
                  portp->stats.rxlost += len;
                  portp->stats.rxtotal += len;
            } else {
                  len = MIN(len, buflen);
                  if (len > 0) {
                        unsigned char *ptr;
                        outb(GRXFIFO, (ioaddr + XP_ADDR));
                        tty_prepare_flip_string(tty, &ptr, len);
                        insb((ioaddr + XP_DATA), ptr, len);
                        tty_schedule_flip(tty);
                        portp->stats.rxtotal += len;
                  }
            }
      } else {
            stl_sc26198rxbadchars(portp);
      }

/*
 *    If we are TX flow controlled and in IXANY mode then we may need
 *    to unflow control here. We gotta do this because of the automatic
 *    flow control modes of the sc26198.
 */
      if (test_bit(ASYI_TXFLOWED, &portp->istate)) {
            if ((tty != (struct tty_struct *) NULL) &&
                (tty->termios != (struct termios *) NULL) &&
                (tty->termios->c_iflag & IXANY)) {
                  stl_sc26198txunflow(portp, tty);
            }
      }
}

/*****************************************************************************/

/*
 *    Process an RX bad character.
 */

static inline void stl_sc26198rxbadch(stlport_t *portp, unsigned char status, char ch)
{
      struct tty_struct *tty;
      unsigned int            ioaddr;

      tty = portp->tty;
      ioaddr = portp->ioaddr;

      if (status & SR_RXPARITY)
            portp->stats.rxparity++;
      if (status & SR_RXFRAMING)
            portp->stats.rxframing++;
      if (status & SR_RXOVERRUN)
            portp->stats.rxoverrun++;
      if (status & SR_RXBREAK)
            portp->stats.rxbreaks++;

      if ((tty != (struct tty_struct *) NULL) &&
          ((portp->rxignoremsk & status) == 0)) {
            if (portp->rxmarkmsk & status) {
                  if (status & SR_RXBREAK) {
                        status = TTY_BREAK;
                        if (portp->flags & ASYNC_SAK) {
                              do_SAK(tty);
                              BRDENABLE(portp->brdnr, portp->pagenr);
                        }
                  } else if (status & SR_RXPARITY) {
                        status = TTY_PARITY;
                  } else if (status & SR_RXFRAMING) {
                        status = TTY_FRAME;
                  } else if(status & SR_RXOVERRUN) {
                        status = TTY_OVERRUN;
                  } else {
                        status = 0;
                  }
            } else {
                  status = 0;
            }

            tty_insert_flip_char(tty, ch, status);
            tty_schedule_flip(tty);

            if (status == 0)
                  portp->stats.rxtotal++;
      }
}

/*****************************************************************************/

/*
 *    Process all characters in the RX FIFO of the UART. Check all char
 *    status bytes as well, and process as required. We need to check
 *    all bytes in the FIFO, in case some more enter the FIFO while we
 *    are here. To get the exact character error type we need to switch
 *    into CHAR error mode (that is why we need to make sure we empty
 *    the FIFO).
 */

static void stl_sc26198rxbadchars(stlport_t *portp)
{
      unsigned char     status, mr1;
      char        ch;

/*
 *    To get the precise error type for each character we must switch
 *    back into CHAR error mode.
 */
      mr1 = stl_sc26198getreg(portp, MR1);
      stl_sc26198setreg(portp, MR1, (mr1 & ~MR1_ERRBLOCK));

      while ((status = stl_sc26198getreg(portp, SR)) & SR_RXRDY) {
            stl_sc26198setreg(portp, SCCR, CR_CLEARRXERR);
            ch = stl_sc26198getreg(portp, RXFIFO);
            stl_sc26198rxbadch(portp, status, ch);
      }

/*
 *    To get correct interrupt class we must switch back into BLOCK
 *    error mode.
 */
      stl_sc26198setreg(portp, MR1, mr1);
}

/*****************************************************************************/

/*
 *    Other interrupt handler. This includes modem signals, flow
 *    control actions, etc. Most stuff is left to off-level interrupt
 *    processing time.
 */

static void stl_sc26198otherisr(stlport_t *portp, unsigned int iack)
{
      unsigned char     cir, ipr, xisr;

#ifdef DEBUG
      printk("stl_sc26198otherisr(portp=%x,iack=%x)\n", (int) portp, iack);
#endif

      cir = stl_sc26198getglobreg(portp, CIR);

      switch (cir & CIR_SUBTYPEMASK) {
      case CIR_SUBCOS:
            ipr = stl_sc26198getreg(portp, IPR);
            if (ipr & IPR_DCDCHANGE) {
                  set_bit(ASYI_DCDCHANGE, &portp->istate);
                  schedule_work(&portp->tqueue); 
                  portp->stats.modem++;
            }
            break;
      case CIR_SUBXONXOFF:
            xisr = stl_sc26198getreg(portp, XISR);
            if (xisr & XISR_RXXONGOT) {
                  set_bit(ASYI_TXFLOWED, &portp->istate);
                  portp->stats.txxoff++;
            }
            if (xisr & XISR_RXXOFFGOT) {
                  clear_bit(ASYI_TXFLOWED, &portp->istate);
                  portp->stats.txxon++;
            }
            break;
      case CIR_SUBBREAK:
            stl_sc26198setreg(portp, SCCR, CR_BREAKRESET);
            stl_sc26198rxbadchars(portp);
            break;
      default:
            break;
      }
}

/*****************************************************************************/

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