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gpio.c

/*
 * arch/arm/mach-ns9xxx/gpio.c
 *
 * Copyright (C) 2006,2007 by Digi International Inc.
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 */
#include <linux/compiler.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/module.h>

#include <asm/arch-ns9xxx/gpio.h>
#include <asm/arch-ns9xxx/processor.h>
#include <asm/arch-ns9xxx/processor-ns9360.h>
#include <asm/bug.h>
#include <asm/types.h>
#include <asm/bitops.h>

#include "gpio-ns9360.h"

#if defined(CONFIG_PROCESSOR_NS9360)
#define GPIO_MAX 72
#elif defined(CONFIG_PROCESSOR_NS9750)
#define GPIO_MAX 49
#endif

/* protects BBU_GCONFx and BBU_GCTRLx */
static spinlock_t gpio_lock = __SPIN_LOCK_UNLOCKED(gpio_lock);

/* only access gpiores with atomic ops */
static DECLARE_BITMAP(gpiores, GPIO_MAX + 1);

static inline int ns9xxx_valid_gpio(unsigned gpio)
{
#if defined(CONFIG_PROCESSOR_NS9360)
      if (processor_is_ns9360())
            return gpio <= 72;
      else
#endif
#if defined(CONFIG_PROCESSOR_NS9750)
      if (processor_is_ns9750())
            return gpio <= 49;
      else
#endif
      {
            BUG();
            return 0;
      }
}

int gpio_request(unsigned gpio, const char *label)
{
      if (likely(ns9xxx_valid_gpio(gpio)))
            return test_and_set_bit(gpio, gpiores) ? -EBUSY : 0;
      else
            return -EINVAL;
}
EXPORT_SYMBOL(gpio_request);

void gpio_free(unsigned gpio)
{
      clear_bit(gpio, gpiores);
      return;
}
EXPORT_SYMBOL(gpio_free);

int gpio_direction_input(unsigned gpio)
{
      if (likely(ns9xxx_valid_gpio(gpio))) {
            int ret = -EINVAL;
            unsigned long flags;

            spin_lock_irqsave(&gpio_lock, flags);
#if defined(CONFIG_PROCESSOR_NS9360)
            if (processor_is_ns9360())
                  ret = __ns9360_gpio_configure(gpio, 0, 0, 3);
            else
#endif
                  BUG();

            spin_unlock_irqrestore(&gpio_lock, flags);

            return ret;

      } else
            return -EINVAL;
}
EXPORT_SYMBOL(gpio_direction_input);

int gpio_direction_output(unsigned gpio, int value)
{
      if (likely(ns9xxx_valid_gpio(gpio))) {
            int ret = -EINVAL;
            unsigned long flags;

            gpio_set_value(gpio, value);

            spin_lock_irqsave(&gpio_lock, flags);
#if defined(CONFIG_PROCESSOR_NS9360)
            if (processor_is_ns9360())
                  ret = __ns9360_gpio_configure(gpio, 1, 0, 3);
            else
#endif
                  BUG();

            spin_unlock_irqrestore(&gpio_lock, flags);

            return ret;
      } else
            return -EINVAL;
}
EXPORT_SYMBOL(gpio_direction_output);

int gpio_get_value(unsigned gpio)
{
#if defined(CONFIG_PROCESSOR_NS9360)
      if (processor_is_ns9360())
            return ns9360_gpio_get_value(gpio);
      else
#endif
      {
            BUG();
            return -EINVAL;
      }
}
EXPORT_SYMBOL(gpio_get_value);

void gpio_set_value(unsigned gpio, int value)
{
      unsigned long flags;
      spin_lock_irqsave(&gpio_lock, flags);
#if defined(CONFIG_PROCESSOR_NS9360)
      if (processor_is_ns9360())
            ns9360_gpio_set_value(gpio, value);
      else
#endif
            BUG();

      spin_unlock_irqrestore(&gpio_lock, flags);
}
EXPORT_SYMBOL(gpio_set_value);

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