140 строки
3.2 KiB
C
140 строки
3.2 KiB
C
/*
|
|
* 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);
|
|
else
|
|
val &= ~BIT(gpio);
|
|
LOONGSON_GPIODATA = val;
|
|
spin_unlock(&gpio_lock);
|
|
}
|
|
|
|
static int loongson_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
|
|
{
|
|
u32 temp;
|
|
|
|
spin_lock(&gpio_lock);
|
|
temp = LOONGSON_GPIOIE;
|
|
temp |= BIT(gpio);
|
|
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;
|
|
|
|
loongson_gpio_set_value(chip, gpio, level);
|
|
spin_lock(&gpio_lock);
|
|
temp = LOONGSON_GPIOIE;
|
|
temp &= ~BIT(gpio);
|
|
LOONGSON_GPIOIE = temp;
|
|
spin_unlock(&gpio_lock);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int loongson_gpio_probe(struct platform_device *pdev)
|
|
{
|
|
struct gpio_chip *gc;
|
|
struct device *dev = &pdev->dev;
|
|
|
|
gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL);
|
|
if (!gc)
|
|
return -ENOMEM;
|
|
|
|
gc->label = "loongson-gpio-chip";
|
|
gc->base = 0;
|
|
gc->ngpio = LOONGSON_N_GPIO;
|
|
gc->get = loongson_gpio_get_value;
|
|
gc->set = loongson_gpio_set_value;
|
|
gc->direction_input = loongson_gpio_direction_input;
|
|
gc->direction_output = loongson_gpio_direction_output;
|
|
|
|
return gpiochip_add_data(gc, NULL);
|
|
}
|
|
|
|
static struct platform_driver loongson_gpio_driver = {
|
|
.driver = {
|
|
.name = "loongson-gpio",
|
|
},
|
|
.probe = loongson_gpio_probe,
|
|
};
|
|
|
|
static int __init loongson_gpio_setup(void)
|
|
{
|
|
struct platform_device *pdev;
|
|
int ret;
|
|
|
|
ret = platform_driver_register(&loongson_gpio_driver);
|
|
if (ret) {
|
|
pr_err("error registering loongson GPIO driver\n");
|
|
return ret;
|
|
}
|
|
|
|
pdev = platform_device_register_simple("loongson-gpio", -1, NULL, 0);
|
|
return PTR_ERR_OR_ZERO(pdev);
|
|
}
|
|
postcore_initcall(loongson_gpio_setup);
|