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gpio.c

/* $Id: gpio.c,v 1.17 2005/06/19 17:06:46 starvik Exp $
 *
 * Etrax general port I/O device
 *
 * Copyright (c) 1999, 2000, 2001, 2002 Axis Communications AB
 *
 * Authors:    Bjorn Wesen      (initial version)
 *             Ola Knutsson     (LED handling)
 *             Johan Adolfsson  (read/set directions, write, port G)
 *
 * $Log: gpio.c,v $
 * Revision 1.17  2005/06/19 17:06:46  starvik
 * Merge of Linux 2.6.12.
 *
 * Revision 1.16  2005/03/07 13:02:29  starvik
 * Protect driver global states with spinlock
 *
 * Revision 1.15  2005/01/05 06:08:55  starvik
 * No need to do local_irq_disable after local_irq_save.
 *
 * Revision 1.14  2004/12/13 12:21:52  starvik
 * Added I/O and DMA allocators from Linux 2.4
 *
 * Revision 1.12  2004/08/24 07:19:59  starvik
 * Whitespace cleanup
 *
 * Revision 1.11  2004/05/14 07:58:03  starvik
 * Merge of changes from 2.4
 *
 * Revision 1.9  2003/09/11 07:29:48  starvik
 * Merge of Linux 2.6.0-test5
 *
 * Revision 1.8  2003/07/04 08:27:37  starvik
 * Merge of Linux 2.5.74
 *
 * Revision 1.7  2003/01/10 07:44:07  starvik
 * init_ioremap is now called by kernel before drivers are initialized
 *
 * Revision 1.6  2002/12/11 13:13:57  starvik
 * Added arch/ to v10 specific includes
 * Added fix from Linux 2.4 in serial.c (flush_to_flip_buffer)
 *
 * Revision 1.5  2002/11/20 11:56:11  starvik
 * Merge of Linux 2.5.48
 *
 * Revision 1.4  2002/11/18 10:10:05  starvik
 * Linux 2.5 port of latest gpio.c from Linux 2.4
 *
 * Revision 1.20  2002/10/16 21:16:24  johana
 * Added support for PA high level interrupt.
 * That gives 2ms response time with iodtest for high levels and 2-12 ms
 * response time on low levels if the check is not made in
 * process.c:cpu_idle() as well.
 *
 * Revision 1.19  2002/10/14 18:27:33  johana
 * Implemented alarm handling so select() now works.
 * Latency is around 6-9 ms with a etrax_gpio_wake_up_check() in
 * cpu_idle().
 * Otherwise I get 15-18 ms (same as doing the poll in userspace -
 * but less overhead).
 * TODO? Perhaps we should add the check in IMMEDIATE_BH (or whatever it
 * is in 2.4) as well?
 * TODO? Perhaps call request_irq()/free_irq() only when needed?
 * Increased version to 2.5
 *
 * Revision 1.18  2002/10/11 15:02:00  johana
 * Mask inverted 8 bit value in setget_input().
 *
 * Revision 1.17  2002/06/17 15:53:01  johana
 * Added IO_READ_INBITS, IO_READ_OUTBITS, IO_SETGET_INPUT and IO_SETGET_OUTPUT
 * that take a pointer as argument and thus can handle 32 bit ports (G)
 * correctly.
 * These should be used instead of IO_READBITS, IO_SETINPUT and IO_SETOUTPUT.
 * (especially if Port G bit 31 is used)
 *
 * Revision 1.16  2002/06/17 09:59:51  johana
 * Returning 32 bit values in the ioctl return value doesn't work if bit
 * 31 is set (could happen for port G), so mask it of with 0x7FFFFFFF.
 * A new set of ioctl's will be added.
 *
 * Revision 1.15  2002/05/06 13:19:13  johana
 * IO_SETINPUT returns mask with bit set = inputs for PA and PB as well.
 *
 * Revision 1.14  2002/04/12 12:01:53  johana
 * Use global r_port_g_data_shadow.
 * Moved gpio_init_port_g() closer to gpio_init() and marked it __init.
 *
 * Revision 1.13  2002/04/10 12:03:55  johana
 * Added support for port G /dev/gpiog (minor 3).
 * Changed indentation on switch cases.
 * Fixed other spaces to tabs.
 *
 * Revision 1.12  2001/11/12 19:42:15  pkj
 * * Corrected return values from gpio_leds_ioctl().
 * * Fixed compiler warnings.
 *
 * Revision 1.11  2001/10/30 14:39:12  johana
 * Added D() around gpio_write printk.
 *
 * Revision 1.10  2001/10/25 10:24:42  johana
 * Added IO_CFG_WRITE_MODE ioctl and write method that can do fast
 * bittoggling in the kernel. (This speeds up programming an FPGA with 450kB
 * from ~60 seconds to 4 seconds).
 * Added save_flags/cli/restore_flags in ioctl.
 *
 * Revision 1.9  2001/05/04 14:16:07  matsfg
 * Corrected spelling error
 *
 * Revision 1.8  2001/04/27 13:55:26  matsfg
 * Moved initioremap.
 * Turns off all LEDS on init.
 * Added support for shutdown and powerbutton.
 *
 * Revision 1.7  2001/04/04 13:30:08  matsfg
 * Added bitset and bitclear for leds. Calls init_ioremap to set up memmapping
 *
 * Revision 1.6  2001/03/26 16:03:06  bjornw
 * Needs linux/config.h
 *
 * Revision 1.5  2001/03/26 14:22:03  bjornw
 * Namechange of some config options
 *
 * Revision 1.4  2001/02/27 13:52:48  bjornw
 * malloc.h -> slab.h
 *
 * Revision 1.3  2001/01/24 15:06:48  bjornw
 * gpio_wq correct type
 *
 * Revision 1.2  2001/01/18 16:07:30  bjornw
 * 2.4 port
 *
 * Revision 1.1  2001/01/18 15:55:16  bjornw
 * Verbatim copy of etraxgpio.c from elinux 2.0 added
 *
 *
 */


#include <linux/module.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/string.h>
#include <linux/poll.h>
#include <linux/init.h>
#include <linux/interrupt.h>

#include <asm/etraxgpio.h>
#include <asm/arch/svinto.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/irq.h>
#include <asm/arch/io_interface_mux.h>

#define GPIO_MAJOR 120  /* experimental MAJOR number */

#define D(x)

#if 0
static int dp_cnt;
#define DP(x) do { dp_cnt++; if (dp_cnt % 1000 == 0) x; }while(0)
#else
#define DP(x)
#endif
      
static char gpio_name[] = "etrax gpio";

#if 0
static wait_queue_head_t *gpio_wq;
#endif

static int gpio_ioctl(struct inode *inode, struct file *file,
                  unsigned int cmd, unsigned long arg);
static ssize_t gpio_write(struct file * file, const char * buf, size_t count,
                          loff_t *off);
static int gpio_open(struct inode *inode, struct file *filp);
static int gpio_release(struct inode *inode, struct file *filp);
static unsigned int gpio_poll(struct file *filp, struct poll_table_struct *wait);

/* private data per open() of this driver */

struct gpio_private {
      struct gpio_private *next;
      /* These fields are for PA and PB only */
      volatile unsigned char *port, *shadow;
      volatile unsigned char *dir, *dir_shadow;
      unsigned char changeable_dir;
      unsigned char changeable_bits;
      unsigned char clk_mask;
      unsigned char data_mask;
      unsigned char write_msb;
      unsigned char pad1, pad2, pad3;
      /* These fields are generic */
      unsigned long highalarm, lowalarm;
      wait_queue_head_t alarm_wq;
      int minor;
};

/* linked list of alarms to check for */

static struct gpio_private *alarmlist = 0;

static int gpio_some_alarms = 0; /* Set if someone uses alarm */
static unsigned long gpio_pa_irq_enabled_mask = 0;

static DEFINE_SPINLOCK(gpio_lock); /* Protect directions etc */

/* Port A and B use 8 bit access, but Port G is 32 bit */
#define NUM_PORTS (GPIO_MINOR_B+1)

static volatile unsigned char *ports[NUM_PORTS] = { 
      R_PORT_PA_DATA, 
      R_PORT_PB_DATA,
};
static volatile unsigned char *shads[NUM_PORTS] = {
      &port_pa_data_shadow, 
      &port_pb_data_shadow
};

/* What direction bits that are user changeable 1=changeable*/
#ifndef CONFIG_ETRAX_PA_CHANGEABLE_DIR
#define CONFIG_ETRAX_PA_CHANGEABLE_DIR 0x00
#endif
#ifndef CONFIG_ETRAX_PB_CHANGEABLE_DIR
#define CONFIG_ETRAX_PB_CHANGEABLE_DIR 0x00
#endif

#ifndef CONFIG_ETRAX_PA_CHANGEABLE_BITS
#define CONFIG_ETRAX_PA_CHANGEABLE_BITS 0xFF
#endif
#ifndef CONFIG_ETRAX_PB_CHANGEABLE_BITS
#define CONFIG_ETRAX_PB_CHANGEABLE_BITS 0xFF
#endif


static unsigned char changeable_dir[NUM_PORTS] = { 
      CONFIG_ETRAX_PA_CHANGEABLE_DIR,
      CONFIG_ETRAX_PB_CHANGEABLE_DIR 
};
static unsigned char changeable_bits[NUM_PORTS] = { 
      CONFIG_ETRAX_PA_CHANGEABLE_BITS,
      CONFIG_ETRAX_PB_CHANGEABLE_BITS 
};

static volatile unsigned char *dir[NUM_PORTS] = { 
      R_PORT_PA_DIR, 
      R_PORT_PB_DIR 
};

static volatile unsigned char *dir_shadow[NUM_PORTS] = {
      &port_pa_dir_shadow, 
      &port_pb_dir_shadow 
};

/* All bits in port g that can change dir. */
static const unsigned long int changeable_dir_g_mask = 0x01FFFF01;

/* Port G is 32 bit, handle it special, some bits are both inputs 
   and outputs at the same time, only some of the bits can change direction
   and some of them in groups of 8 bit. */
static unsigned long changeable_dir_g;
static unsigned long dir_g_in_bits;
static unsigned long dir_g_out_bits;
static unsigned long dir_g_shadow; /* 1=output */

#define USE_PORTS(priv) ((priv)->minor <= GPIO_MINOR_B)



static unsigned int 
gpio_poll(struct file *file,
        poll_table *wait)
{
      unsigned int mask = 0;
      struct gpio_private *priv = (struct gpio_private *)file->private_data;
      unsigned long data;
      spin_lock(&gpio_lock);
      poll_wait(file, &priv->alarm_wq, wait);
      if (priv->minor == GPIO_MINOR_A) {
            unsigned long flags;
            unsigned long tmp;
            data = *R_PORT_PA_DATA;
            /* PA has support for high level interrupt -
             * lets activate for those low and with highalarm set
             */
            tmp = ~data & priv->highalarm & 0xFF;
            tmp = (tmp << R_IRQ_MASK1_SET__pa0__BITNR);
            local_irq_save(flags);
            gpio_pa_irq_enabled_mask |= tmp;
            *R_IRQ_MASK1_SET = tmp;
            local_irq_restore(flags);

      } else if (priv->minor == GPIO_MINOR_B)
            data = *R_PORT_PB_DATA;
      else if (priv->minor == GPIO_MINOR_G)
            data = *R_PORT_G_DATA;
      else
            return 0;
      
      if ((data & priv->highalarm) ||
          (~data & priv->lowalarm)) {
            mask = POLLIN|POLLRDNORM;
      }

      spin_unlock(&gpio_lock);
      
      DP(printk("gpio_poll ready: mask 0x%08X\n", mask));

      return mask;
}

int etrax_gpio_wake_up_check(void)
{
      struct gpio_private *priv = alarmlist;
      unsigned long data = 0;
        int ret = 0;
      spin_lock(&gpio_lock);
      while (priv) {
            if (USE_PORTS(priv)) {
                  data = *priv->port;
            } else if (priv->minor == GPIO_MINOR_G) {
                  data = *R_PORT_G_DATA;
            }
            if ((data & priv->highalarm) ||
                (~data & priv->lowalarm)) {
                  DP(printk("etrax_gpio_wake_up_check %i\n",priv->minor));
                  wake_up_interruptible(&priv->alarm_wq);
                        ret = 1;
            }
            priv = priv->next;
      }
      spin_unlock(&gpio_lock);
        return ret;
}

static irqreturn_t
gpio_poll_timer_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
      if (gpio_some_alarms) {
            etrax_gpio_wake_up_check();
                return IRQ_HANDLED;
      }
        return IRQ_NONE;
}

static irqreturn_t
gpio_pa_interrupt(int irq, void *dev_id, struct pt_regs *regs)
{
      unsigned long tmp;
      spin_lock(&gpio_lock);
      /* Find what PA interrupts are active */
      tmp = (*R_IRQ_READ1);

      /* Find those that we have enabled */
      tmp &= gpio_pa_irq_enabled_mask;

      /* Clear them.. */
      *R_IRQ_MASK1_CLR = tmp;
      gpio_pa_irq_enabled_mask &= ~tmp;

      spin_unlock(&gpio_lock);

      if (gpio_some_alarms) {
            return IRQ_RETVAL(etrax_gpio_wake_up_check());
      }
        return IRQ_NONE;
}


static ssize_t gpio_write(struct file * file, const char * buf, size_t count,
                          loff_t *off)
{
      struct gpio_private *priv = (struct gpio_private *)file->private_data;
      unsigned char data, clk_mask, data_mask, write_msb;
      unsigned long flags;

      spin_lock(&gpio_lock);

      ssize_t retval = count;
      if (priv->minor !=GPIO_MINOR_A && priv->minor != GPIO_MINOR_B) {
            return -EFAULT;
      }
    
      if (!access_ok(VERIFY_READ, buf, count)) {
            return -EFAULT;
      }
      clk_mask = priv->clk_mask;
      data_mask = priv->data_mask;
      /* It must have been configured using the IO_CFG_WRITE_MODE */
      /* Perhaps a better error code? */
      if (clk_mask == 0 || data_mask == 0) {
            return -EPERM;
      }
      write_msb = priv->write_msb;
      D(printk("gpio_write: %lu to data 0x%02X clk 0x%02X msb: %i\n",count, data_mask, clk_mask, write_msb));
      while (count--) {
            int i;
            data = *buf++;
            if (priv->write_msb) {
                  for (i = 7; i >= 0;i--) {
                        local_irq_save(flags);
                        *priv->port = *priv->shadow &= ~clk_mask;
                        if (data & 1<<i)
                              *priv->port = *priv->shadow |= data_mask;
                        else
                              *priv->port = *priv->shadow &= ~data_mask;
                  /* For FPGA: min 5.0ns (DCC) before CCLK high */
                        *priv->port = *priv->shadow |= clk_mask;
                        local_irq_restore(flags);
                  }
            } else {
                  for (i = 0; i <= 7;i++) {
                        local_irq_save(flags);
                        *priv->port = *priv->shadow &= ~clk_mask;
                        if (data & 1<<i)
                              *priv->port = *priv->shadow |= data_mask;
                        else
                              *priv->port = *priv->shadow &= ~data_mask;
                  /* For FPGA: min 5.0ns (DCC) before CCLK high */
                        *priv->port = *priv->shadow |= clk_mask;
                        local_irq_restore(flags);
                  }
            }
      }
      spin_unlock(&gpio_lock);
      return retval;
}



static int
gpio_open(struct inode *inode, struct file *filp)
{
      struct gpio_private *priv;
      int p = iminor(inode);

      if (p > GPIO_MINOR_LAST)
            return -EINVAL;

      priv = (struct gpio_private *)kmalloc(sizeof(struct gpio_private), 
                                    GFP_KERNEL);

      if (!priv)
            return -ENOMEM;

      priv->minor = p;

      /* initialize the io/alarm struct and link it into our alarmlist */

      priv->next = alarmlist;
      alarmlist = priv;
      if (USE_PORTS(priv)) { /* A and B */
            priv->port = ports[p];
            priv->shadow = shads[p];
            priv->dir = dir[p];
            priv->dir_shadow = dir_shadow[p];
            priv->changeable_dir = changeable_dir[p];
            priv->changeable_bits = changeable_bits[p];
      } else {
            priv->port = NULL;
            priv->shadow = NULL;
            priv->dir = NULL;
            priv->dir_shadow = NULL;
            priv->changeable_dir = 0;
            priv->changeable_bits = 0;
      }

      priv->highalarm = 0;
      priv->lowalarm = 0;
      priv->clk_mask = 0;
      priv->data_mask = 0;
      init_waitqueue_head(&priv->alarm_wq);

      filp->private_data = (void *)priv;

      return 0;
}

static int
gpio_release(struct inode *inode, struct file *filp)
{
      struct gpio_private *p;
      struct gpio_private *todel;

      spin_lock(&gpio_lock);

        p = alarmlist;
        todel = (struct gpio_private *)filp->private_data;

      /* unlink from alarmlist and free the private structure */

      if (p == todel) {
            alarmlist = todel->next;
      } else {
            while (p->next != todel)
                  p = p->next;
            p->next = todel->next;
      }

      kfree(todel);
      /* Check if there are still any alarms set */
      p = alarmlist;
      while (p) {
            if (p->highalarm | p->lowalarm) {
                  gpio_some_alarms = 1;
                  return 0;
            }
            p = p->next;
      }
      gpio_some_alarms = 0;
      spin_unlock(&gpio_lock);
      return 0;
}

/* Main device API. ioctl's to read/set/clear bits, as well as to 
 * set alarms to wait for using a subsequent select().
 */

unsigned long inline setget_input(struct gpio_private *priv, unsigned long arg)
{
      /* Set direction 0=unchanged 1=input, 
       * return mask with 1=input 
       */
      unsigned long flags;
      if (USE_PORTS(priv)) {
            local_irq_save(flags);
            *priv->dir = *priv->dir_shadow &= 
            ~((unsigned char)arg & priv->changeable_dir);
            local_irq_restore(flags);
            return ~(*priv->dir_shadow) & 0xFF; /* Only 8 bits */
      } else if (priv->minor == GPIO_MINOR_G) {
            /* We must fiddle with R_GEN_CONFIG to change dir */
            local_irq_save(flags);
            if (((arg & dir_g_in_bits) != arg) && 
                (arg & changeable_dir_g)) {
                  arg &= changeable_dir_g;
                  /* Clear bits in genconfig to set to input */
                  if (arg & (1<<0)) {
                        genconfig_shadow &= ~IO_MASK(R_GEN_CONFIG,g0dir);
                        dir_g_in_bits |= (1<<0);
                        dir_g_out_bits &= ~(1<<0);
                  }
                  if ((arg & 0x0000FF00) == 0x0000FF00) {
                        genconfig_shadow &= ~IO_MASK(R_GEN_CONFIG,g8_15dir);
                        dir_g_in_bits |= 0x0000FF00;
                        dir_g_out_bits &= ~0x0000FF00;
                  }
                  if ((arg & 0x00FF0000) == 0x00FF0000) {
                        genconfig_shadow &= ~IO_MASK(R_GEN_CONFIG,g16_23dir);
                        dir_g_in_bits |= 0x00FF0000;
                        dir_g_out_bits &= ~0x00FF0000;
                  }
                  if (arg & (1<<24)) {
                        genconfig_shadow &= ~IO_MASK(R_GEN_CONFIG,g24dir);
                        dir_g_in_bits |= (1<<24);
                        dir_g_out_bits &= ~(1<<24);
                  }
                  D(printk(KERN_INFO "gpio: SETINPUT on port G set "
                         "genconfig to 0x%08lX "
                         "in_bits: 0x%08lX "
                         "out_bits: 0x%08lX\n",
                           (unsigned long)genconfig_shadow,
                           dir_g_in_bits, dir_g_out_bits));
                  *R_GEN_CONFIG = genconfig_shadow;
                  /* Must be a >120 ns delay before writing this again */
                        
            }
            local_irq_restore(flags);
            return dir_g_in_bits;
      }
      return 0;
} /* setget_input */

unsigned long inline setget_output(struct gpio_private *priv, unsigned long arg)
{
      unsigned long flags;
      if (USE_PORTS(priv)) {
            local_irq_save(flags);
            *priv->dir = *priv->dir_shadow |= 
              ((unsigned char)arg & priv->changeable_dir);
            local_irq_restore(flags);
            return *priv->dir_shadow;
      } else if (priv->minor == GPIO_MINOR_G) {
            /* We must fiddle with R_GEN_CONFIG to change dir */              
            local_irq_save(flags);
            if (((arg & dir_g_out_bits) != arg) &&
                (arg & changeable_dir_g)) {
                  /* Set bits in genconfig to set to output */
                  if (arg & (1<<0)) {
                        genconfig_shadow |= IO_MASK(R_GEN_CONFIG,g0dir);
                        dir_g_out_bits |= (1<<0);
                        dir_g_in_bits &= ~(1<<0);
                  }
                  if ((arg & 0x0000FF00) == 0x0000FF00) {
                        genconfig_shadow |= IO_MASK(R_GEN_CONFIG,g8_15dir);
                        dir_g_out_bits |= 0x0000FF00;
                        dir_g_in_bits &= ~0x0000FF00;
                  }
                  if ((arg & 0x00FF0000) == 0x00FF0000) {
                        genconfig_shadow |= IO_MASK(R_GEN_CONFIG,g16_23dir);
                        dir_g_out_bits |= 0x00FF0000;
                        dir_g_in_bits &= ~0x00FF0000;
                  }
                  if (arg & (1<<24)) {
                        genconfig_shadow |= IO_MASK(R_GEN_CONFIG,g24dir);
                        dir_g_out_bits |= (1<<24);
                        dir_g_in_bits &= ~(1<<24);
                  }
                  D(printk(KERN_INFO "gpio: SETOUTPUT on port G set "
                         "genconfig to 0x%08lX "
                         "in_bits: 0x%08lX "
                         "out_bits: 0x%08lX\n",
                           (unsigned long)genconfig_shadow,
                           dir_g_in_bits, dir_g_out_bits));
                  *R_GEN_CONFIG = genconfig_shadow;
                  /* Must be a >120 ns delay before writing this again */
            }
            local_irq_restore(flags);
            return dir_g_out_bits & 0x7FFFFFFF;
      }
      return 0;
} /* setget_output */

static int
gpio_leds_ioctl(unsigned int cmd, unsigned long arg);

static int
gpio_ioctl(struct inode *inode, struct file *file,
         unsigned int cmd, unsigned long arg)
{
      unsigned long flags;
      unsigned long val;
        int ret = 0;

      struct gpio_private *priv = (struct gpio_private *)file->private_data;
      if (_IOC_TYPE(cmd) != ETRAXGPIO_IOCTYPE) {
            return -EINVAL;
      }

      spin_lock(&gpio_lock);

      switch (_IOC_NR(cmd)) {
      case IO_READBITS: /* Use IO_READ_INBITS and IO_READ_OUTBITS instead */
            // read the port
            if (USE_PORTS(priv)) {
                  ret =  *priv->port;
            } else if (priv->minor == GPIO_MINOR_G) {
                  ret =  (*R_PORT_G_DATA) & 0x7FFFFFFF;
            }
            break;
      case IO_SETBITS:
            local_irq_save(flags);
            // set changeable bits with a 1 in arg
            if (USE_PORTS(priv)) {
                  *priv->port = *priv->shadow |= 
                    ((unsigned char)arg & priv->changeable_bits);
            } else if (priv->minor == GPIO_MINOR_G) {
                  *R_PORT_G_DATA = port_g_data_shadow |= (arg & dir_g_out_bits);
            }
            local_irq_restore(flags);
            break;
      case IO_CLRBITS:
            local_irq_save(flags);
            // clear changeable bits with a 1 in arg
            if (USE_PORTS(priv)) {
                  *priv->port = *priv->shadow &= 
                   ~((unsigned char)arg & priv->changeable_bits);
            } else if (priv->minor == GPIO_MINOR_G) {
                  *R_PORT_G_DATA = port_g_data_shadow &= ~((unsigned long)arg & dir_g_out_bits);
            }
            local_irq_restore(flags);
            break;
      case IO_HIGHALARM:
            // set alarm when bits with 1 in arg go high
            priv->highalarm |= arg;
            gpio_some_alarms = 1;
            break;
      case IO_LOWALARM:
            // set alarm when bits with 1 in arg go low
            priv->lowalarm |= arg;
            gpio_some_alarms = 1;
            break;
      case IO_CLRALARM:
            // clear alarm for bits with 1 in arg
            priv->highalarm &= ~arg;
            priv->lowalarm  &= ~arg;
            {
                  /* Must update gpio_some_alarms */
                  struct gpio_private *p = alarmlist;
                  int some_alarms;
                  some_alarms = 0;
                  while (p) {
                        if (p->highalarm | p->lowalarm) {
                              some_alarms = 1;
                              break;
                        }
                        p = p->next;
                  }
                  gpio_some_alarms = some_alarms;
            }
            break;
      case IO_READDIR: /* Use IO_SETGET_INPUT/OUTPUT instead! */
            /* Read direction 0=input 1=output */
            if (USE_PORTS(priv)) {
                  ret = *priv->dir_shadow;
            } else if (priv->minor == GPIO_MINOR_G) {
                  /* Note: Some bits are both in and out,
                   * Those that are dual is set here as well.
                   */
                  ret = (dir_g_shadow | dir_g_out_bits) & 0x7FFFFFFF;
            }
            break;
      case IO_SETINPUT: /* Use IO_SETGET_INPUT instead! */
            /* Set direction 0=unchanged 1=input, 
             * return mask with 1=input 
             */
            ret = setget_input(priv, arg) & 0x7FFFFFFF;
            break;
      case IO_SETOUTPUT: /* Use IO_SETGET_OUTPUT instead! */
            /* Set direction 0=unchanged 1=output, 
             * return mask with 1=output 
             */
            ret =  setget_output(priv, arg) & 0x7FFFFFFF;
            break;
      case IO_SHUTDOWN:
            SOFT_SHUTDOWN();
            break;
      case IO_GET_PWR_BT:
#if defined (CONFIG_ETRAX_SOFT_SHUTDOWN)
            ret = (*R_PORT_G_DATA & ( 1 << CONFIG_ETRAX_POWERBUTTON_BIT));
#else
            ret = 0;
#endif
            break;
      case IO_CFG_WRITE_MODE:
            priv->clk_mask = arg & 0xFF;
            priv->data_mask = (arg >> 8) & 0xFF;
            priv->write_msb = (arg >> 16) & 0x01;
            /* Check if we're allowed to change the bits and
             * the direction is correct
             */
            if (!((priv->clk_mask & priv->changeable_bits) &&
                  (priv->data_mask & priv->changeable_bits) &&
                  (priv->clk_mask & *priv->dir_shadow) &&
                  (priv->data_mask & *priv->dir_shadow)))
            {
                  priv->clk_mask = 0;
                  priv->data_mask = 0;
                  ret = -EPERM;
            }
            break;
      case IO_READ_INBITS: 
            /* *arg is result of reading the input pins */
            if (USE_PORTS(priv)) {
                  val = *priv->port;
            } else if (priv->minor == GPIO_MINOR_G) {
                  val = *R_PORT_G_DATA;
            }
            if (copy_to_user((unsigned long*)arg, &val, sizeof(val)))
                  ret = -EFAULT;
            break;
      case IO_READ_OUTBITS:
             /* *arg is result of reading the output shadow */
            if (USE_PORTS(priv)) {
                  val = *priv->shadow;
            } else if (priv->minor == GPIO_MINOR_G) {
                  val = port_g_data_shadow;
            }
            if (copy_to_user((unsigned long*)arg, &val, sizeof(val)))
                  ret = -EFAULT;
            break;
      case IO_SETGET_INPUT: 
            /* bits set in *arg is set to input,
             * *arg updated with current input pins.
             */
            if (copy_from_user(&val, (unsigned long*)arg, sizeof(val)))
            {
                  ret = -EFAULT;
                  break;
            }
            val = setget_input(priv, val);
            if (copy_to_user((unsigned long*)arg, &val, sizeof(val)))
                  ret = -EFAULT;
            break;
      case IO_SETGET_OUTPUT:
            /* bits set in *arg is set to output,
             * *arg updated with current output pins.
             */
            if (copy_from_user(&val, (unsigned long*)arg, sizeof(val)))
            {
                  ret = -EFAULT;
                  break;
            }
            val = setget_output(priv, val);
            if (copy_to_user((unsigned long*)arg, &val, sizeof(val)))
                  ret = -EFAULT;
            break;
      default:
            if (priv->minor == GPIO_MINOR_LEDS)
                  ret = gpio_leds_ioctl(cmd, arg);
            else
                  ret = -EINVAL;
      } /* switch */

      spin_unlock(&gpio_lock);
      return ret;
}

static int
gpio_leds_ioctl(unsigned int cmd, unsigned long arg)
{
      unsigned char green;
      unsigned char red;

      switch (_IOC_NR(cmd)) {
      case IO_LEDACTIVE_SET:
            green = ((unsigned char) arg) & 1;
            red   = (((unsigned char) arg) >> 1) & 1;
            LED_ACTIVE_SET_G(green);
            LED_ACTIVE_SET_R(red);
            break;

      case IO_LED_SETBIT:
            LED_BIT_SET(arg);
            break;

      case IO_LED_CLRBIT:
            LED_BIT_CLR(arg);
            break;

      default:
            return -EINVAL;
      } /* switch */

      return 0;
}

struct file_operations gpio_fops = {
      .owner       = THIS_MODULE,
      .poll        = gpio_poll,
      .ioctl       = gpio_ioctl,
      .write       = gpio_write,
      .open        = gpio_open,
      .release     = gpio_release,
};


void ioif_watcher(const unsigned int gpio_in_available,
              const unsigned int gpio_out_available,
              const unsigned char pa_available,
              const unsigned char pb_available)
{
      unsigned long int flags;
      D(printk("gpio.c: ioif_watcher called\n"));
      D(printk("gpio.c: G in: 0x%08x G out: 0x%08x PA: 0x%02x PB: 0x%02x\n",
             gpio_in_available, gpio_out_available, pa_available, pb_available));

      spin_lock_irqsave(&gpio_lock, flags);

      dir_g_in_bits = gpio_in_available;
      dir_g_out_bits = gpio_out_available;

      /* Initialise the dir_g_shadow etc. depending on genconfig */
      /* 0=input 1=output */
      if (genconfig_shadow & IO_STATE(R_GEN_CONFIG, g0dir, out)) 
            dir_g_shadow |= (1 << 0);
      if (genconfig_shadow & IO_STATE(R_GEN_CONFIG, g8_15dir, out))
            dir_g_shadow |= 0x0000FF00;
      if (genconfig_shadow & IO_STATE(R_GEN_CONFIG, g16_23dir, out))
            dir_g_shadow |= 0x00FF0000;
      if (genconfig_shadow & IO_STATE(R_GEN_CONFIG, g24dir, out))
            dir_g_shadow |= (1 << 24);

      changeable_dir_g = changeable_dir_g_mask;
      changeable_dir_g &= dir_g_out_bits;
      changeable_dir_g &= dir_g_in_bits;
      /* Correct the bits that can change direction */ 
      dir_g_out_bits &= ~changeable_dir_g;
      dir_g_out_bits |= dir_g_shadow;
      dir_g_in_bits &= ~changeable_dir_g;
      dir_g_in_bits |= (~dir_g_shadow & changeable_dir_g);

      spin_unlock_irqrestore(&gpio_lock, flags);

      printk(KERN_INFO "GPIO port G: in_bits: 0x%08lX out_bits: 0x%08lX val: %08lX\n",
             dir_g_in_bits, dir_g_out_bits, (unsigned long)*R_PORT_G_DATA);
      printk(KERN_INFO "GPIO port G: dir: %08lX changeable: %08lX\n",
             dir_g_shadow, changeable_dir_g);
}

/* main driver initialization routine, called from mem.c */

static __init int
gpio_init(void)
{
      int res;
#if defined (CONFIG_ETRAX_CSP0_LEDS)
      int i;
#endif
        printk("gpio init\n");

      /* do the formalities */

      res = register_chrdev(GPIO_MAJOR, gpio_name, &gpio_fops);
      if (res < 0) {
            printk(KERN_ERR "gpio: couldn't get a major number.\n");
            return res;
      }

      /* Clear all leds */
#if defined (CONFIG_ETRAX_CSP0_LEDS) ||  defined (CONFIG_ETRAX_PA_LEDS) || defined (CONFIG_ETRAX_PB_LEDS)
      LED_NETWORK_SET(0);
      LED_ACTIVE_SET(0);
      LED_DISK_READ(0);
      LED_DISK_WRITE(0);

#if defined (CONFIG_ETRAX_CSP0_LEDS)
      for (i = 0; i < 32; i++) {
            LED_BIT_SET(i);
      }
#endif

#endif
      /* The I/O interface allocation watcher will be called when
       * registering it. */
      if (cris_io_interface_register_watcher(ioif_watcher)){
            printk(KERN_WARNING "gpio_init: Failed to install IO if allocator watcher\n");
      }

      printk(KERN_INFO "ETRAX 100LX GPIO driver v2.5, (c) 2001, 2002, 2003, 2004 Axis Communications AB\n");
      /* We call etrax_gpio_wake_up_check() from timer interrupt and
       * from cpu_idle() in kernel/process.c
       * The check in cpu_idle() reduces latency from ~15 ms to ~6 ms
       * in some tests.
       */  
      if (request_irq(TIMER0_IRQ_NBR, gpio_poll_timer_interrupt,
                  IRQF_SHARED | IRQF_DISABLED,"gpio poll", NULL)) {
            printk(KERN_CRIT "err: timer0 irq for gpio\n");
      }
      if (request_irq(PA_IRQ_NBR, gpio_pa_interrupt,
                  IRQF_SHARED | IRQF_DISABLED,"gpio PA", NULL)) {
            printk(KERN_CRIT "err: PA irq for gpio\n");
      }
      

      return res;
}

/* this makes sure that gpio_init is called during kernel boot */

module_init(gpio_init);

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