linux-imx

/*

 *  Loongson-2F/3A/3B GPIO Support

 *

 *  Copyright (c) 2008 Richard Liu,  STMicroelectronics  <richard.liu@st.com>

 *  Copyright (c) 2008-2010 Arnaud Patard <apatard@mandriva.com>

 *  Copyright (c) 2013 Hongbing Hu <huhb@lemote.com>

 *  Copyright (c) 2014 Huacai Chen <chenhc@lemote.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; 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 <linux/gpio/driver.h>

#include <linux/platform_device.h>

#include <linux/bitops.h>

#include <asm/types.h>

#include <loongson.h>

​

#define STLS2F_N_GPIO       4

#define STLS3A_N_GPIO       16

​

#ifdef CONFIG_CPU_LOONGSON3

#define LOONGSON_N_GPIO STLS3A_N_GPIO

#else

#define LOONGSON_N_GPIO STLS2F_N_GPIO

#endif

​

/*

 * Offset into the register where we read lines, we write them from offset 0.

 * This offset is the only thing that stand between us and using

 * GPIO_GENERIC.

 */

#define LOONGSON_GPIO_IN_OFFSET 16

​

static DEFINE_SPINLOCK(gpio_lock);

​

static int loongson_gpio_get_value(struct gpio_chip *chip, unsigned gpio)

{

    u32 val;

​

    spin_lock(&gpio_lock);

    val = LOONGSON_GPIODATA;

    spin_unlock(&gpio_lock);

​

    return !!(val & BIT(gpio + LOONGSON_GPIO_IN_OFFSET));

}

​

static void loongson_gpio_set_value(struct gpio_chip *chip,

        unsigned gpio, int value)

{

    u32 val;

​

    spin_lock(&gpio_lock);

    val = LOONGSON_GPIODATA;

    if (value)

        val |= BIT(gpio);