gpio.c

Go to the documentation of this file.

/*
 *  STLS2F GPIO Support
 *
 *  Copyright (c) 2008 Richard Liu,  STMicroelectronics  <[email protected]>
 *  Copyright (c) 2008-2010 Arnaud Patard <[email protected]>
 *
 *  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.
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/err.h>
#include <asm/types.h>
#include <loongson.h>
#include <linux/gpio.h>

#define STLS2F_N_GPIO       4
#define STLS2F_GPIO_IN_OFFSET   16

static DEFINE_SPINLOCK(gpio_lock);

int gpio_get_value(unsigned gpio)
{
    u32 val;
    u32 mask;

    if (gpio >= STLS2F_N_GPIO)
        return __gpio_get_value(gpio);

    mask = 1 << (gpio + STLS2F_GPIO_IN_OFFSET);
    spin_lock(&gpio_lock);
    val = LOONGSON_GPIODATA;
    spin_unlock(&gpio_lock);

    return ((val & mask) != 0);
}
EXPORT_SYMBOL(gpio_get_value);

void gpio_set_value(unsigned gpio, int state)
{
    u32 val;
    u32 mask;

    if (gpio >= STLS2F_N_GPIO) {
        __gpio_set_value(gpio, state);
        return ;
    }

    mask = 1 << gpio;

    spin_lock(&gpio_lock);
    val = LOONGSON_GPIODATA;
    if (state)
        val |= mask;
    else
        val &= (~mask);
    LOONGSON_GPIODATA = val;
    spin_unlock(&gpio_lock);
}
EXPORT_SYMBOL(gpio_set_value);

int gpio_cansleep(unsigned gpio)
{
    if (gpio < STLS2F_N_GPIO)
        return 0;
    else
        return __gpio_cansleep(gpio);
}
EXPORT_SYMBOL(gpio_cansleep);

static int ls2f_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
{
    u32 temp;
    u32 mask;

    if (gpio >= STLS2F_N_GPIO)
        return -EINVAL;

    spin_lock(&gpio_lock);
    mask = 1 << gpio;
    temp = LOONGSON_GPIOIE;
    temp |= mask;
    LOONGSON_GPIOIE = temp;
    spin_unlock(&gpio_lock);

    return 0;
}

static int ls2f_gpio_direction_output(struct gpio_chip *chip,
        unsigned gpio, int level)
{
    u32 temp;
    u32 mask;

    if (gpio >= STLS2F_N_GPIO)
        return -EINVAL;

    gpio_set_value(gpio, level);
    spin_lock(&gpio_lock);
    mask = 1 << gpio;
    temp = LOONGSON_GPIOIE;
    temp &= (~mask);
    LOONGSON_GPIOIE = temp;
    spin_unlock(&gpio_lock);

    return 0;
}

static int ls2f_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
{
    return gpio_get_value(gpio);
}

static void ls2f_gpio_set_value(struct gpio_chip *chip,
        unsigned gpio, int value)
{
    gpio_set_value(gpio, value);
}

static struct gpio_chip ls2f_chip = {
    .label                  = "ls2f",
    .direction_input        = ls2f_gpio_direction_input,
    .get                    = ls2f_gpio_get_value,
    .direction_output       = ls2f_gpio_direction_output,
    .set                    = ls2f_gpio_set_value,
    .base                   = 0,
    .ngpio                  = STLS2F_N_GPIO,
};

static int __init ls2f_gpio_setup(void)
{
    return gpiochip_add(&ls2f_chip);
}
arch_initcall(ls2f_gpio_setup);