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gpio.c

/*
 * Coldfire generic GPIO support.
 *
 * (C) Copyright 2009, Steven King <sfking@fdwdc.com>
 *
 * 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; version 2 of the License.
 *
 * 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.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/sysdev.h>

#include <asm/gpio.h>
#include <asm/pinmux.h>
#include <asm/mcfgpio.h>

#define MCF_CHIP(chip) container_of(chip, struct mcf_gpio_chip, gpio_chip)

int mcf_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
      unsigned long flags;
      MCFGPIO_PORTTYPE dir;
      struct mcf_gpio_chip *mcf_chip = MCF_CHIP(chip);

      local_irq_save(flags);
      dir = mcfgpio_read(mcf_chip->pddr);
      dir &= ~mcfgpio_bit(chip->base + offset);
      mcfgpio_write(dir, mcf_chip->pddr);
      local_irq_restore(flags);

      return 0;
}

int mcf_gpio_get_value(struct gpio_chip *chip, unsigned offset)
{
      struct mcf_gpio_chip *mcf_chip = MCF_CHIP(chip);

      return mcfgpio_read(mcf_chip->ppdr) & mcfgpio_bit(chip->base + offset);
}

int mcf_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
            int value)
{
      unsigned long flags;
      MCFGPIO_PORTTYPE data;
      struct mcf_gpio_chip *mcf_chip = MCF_CHIP(chip);

      local_irq_save(flags);
      /* write the value to the output latch */
      data = mcfgpio_read(mcf_chip->podr);
      if (value)
            data |= mcfgpio_bit(chip->base + offset);
      else
            data &= ~mcfgpio_bit(chip->base + offset);
      mcfgpio_write(data, mcf_chip->podr);

      /* now set the direction to output */
      data = mcfgpio_read(mcf_chip->pddr);
      data |= mcfgpio_bit(chip->base + offset);
      mcfgpio_write(data, mcf_chip->pddr);
      local_irq_restore(flags);

      return 0;
}

void mcf_gpio_set_value(struct gpio_chip *chip, unsigned offset, int value)
{
      struct mcf_gpio_chip *mcf_chip = MCF_CHIP(chip);

      unsigned long flags;
      MCFGPIO_PORTTYPE data;

      local_irq_save(flags);
      data = mcfgpio_read(mcf_chip->podr);
      if (value)
            data |= mcfgpio_bit(chip->base + offset);
      else
            data &= ~mcfgpio_bit(chip->base + offset);
      mcfgpio_write(data, mcf_chip->podr);
      local_irq_restore(flags);
}

void mcf_gpio_set_value_fast(struct gpio_chip *chip, unsigned offset, int value)
{
      struct mcf_gpio_chip *mcf_chip = MCF_CHIP(chip);

      if (value)
            mcfgpio_write(mcfgpio_bit(chip->base + offset), mcf_chip->setr);
      else
            mcfgpio_write(~mcfgpio_bit(chip->base + offset), mcf_chip->clrr);
}

int mcf_gpio_request(struct gpio_chip *chip, unsigned offset)
{
      struct mcf_gpio_chip *mcf_chip = MCF_CHIP(chip);

      return mcf_chip->gpio_to_pinmux ?
            mcf_pinmux_request(mcf_chip->gpio_to_pinmux[offset], 0) : 0;
}

void mcf_gpio_free(struct gpio_chip *chip, unsigned offset)
{
      struct mcf_gpio_chip *mcf_chip = MCF_CHIP(chip);

      mcf_gpio_direction_input(chip, offset);

      if (mcf_chip->gpio_to_pinmux)
            mcf_pinmux_release(mcf_chip->gpio_to_pinmux[offset], 0);
}

struct sysdev_class mcf_gpio_sysclass = {
      .name = "gpio",
};

static int __init mcf_gpio_sysinit(void)
{
      return sysdev_class_register(&mcf_gpio_sysclass);
}

core_initcall(mcf_gpio_sysinit);

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