gpio-loongson.c
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/*
* 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 <asm/types.h>
#include <loongson.h>
#include <linux/gpio.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
#define LOONGSON_GPIO_IN_OFFSET 16
static DEFINE_SPINLOCK(gpio_lock);
static int loongson_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
{
u32 temp;
u32 mask;
spin_lock(&gpio_lock);
mask = 1 << gpio;
temp = LOONGSON_GPIOIE;
temp |= mask;
LOONGSON_GPIOIE = temp;
spin_unlock(&gpio_lock);
return 0;
}
static int loongson_gpio_direction_output(struct gpio_chip *chip,
unsigned gpio, int level)
{
u32 temp;
u32 mask;
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 loongson_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
{
u32 val;
u32 mask;
mask = 1 << (gpio + LOONGSON_GPIO_IN_OFFSET);
spin_lock(&gpio_lock);
val = LOONGSON_GPIODATA;
spin_unlock(&gpio_lock);
return (val & mask) != 0;
}
static void loongson_gpio_set_value(struct gpio_chip *chip,
unsigned gpio, int value)
{
u32 val;
u32 mask;
mask = 1 << gpio;
spin_lock(&gpio_lock);
val = LOONGSON_GPIODATA;
if (value)
val |= mask;
else
val &= (~mask);
LOONGSON_GPIODATA = val;
spin_unlock(&gpio_lock);
}
static struct gpio_chip loongson_chip = {
.label = "Loongson-gpio-chip",
.direction_input = loongson_gpio_direction_input,
.get = loongson_gpio_get_value,
.direction_output = loongson_gpio_direction_output,
.set = loongson_gpio_set_value,
.base = 0,
.ngpio = LOONGSON_N_GPIO,
.can_sleep = false,
};
static int __init loongson_gpio_setup(void)
{
return gpiochip_add(&loongson_chip);
}
postcore_initcall(loongson_gpio_setup);