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/*
* GPIO Driver for Loongson 1 SoC
*
* Copyright (C) 2015-2016 Zhang, Keguang <keguang.zhang@gmail.com>
*
* This file is licensed under the terms of the GNU General Public
* License version 2. This program is licensed "as is" without any
* warranty of any kind, whether express or implied.
*/
#include <linux/module.h>
#include <linux/gpio/driver.h>
#include <linux/platform_device.h>
#include <linux/bitops.h>
/* Loongson 1 GPIO Register Definitions */
#define GPIO_CFG 0x0
#define GPIO_DIR 0x10
#define GPIO_DATA 0x20
#define GPIO_OUTPUT 0x30
static void __iomem *gpio_reg_base;
static int ls1x_gpio_request(struct gpio_chip *gc, unsigned int offset)
{
unsigned long flags;
spin_lock_irqsave(&gc->bgpio_lock, flags);
__raw_writel(__raw_readl(gpio_reg_base + GPIO_CFG) | BIT(offset),
gpio_reg_base + GPIO_CFG);
spin_unlock_irqrestore(&gc->bgpio_lock, flags);
return 0;
}
static void ls1x_gpio_free(struct gpio_chip *gc, unsigned int offset)
{
unsigned long flags;
spin_lock_irqsave(&gc->bgpio_lock, flags);
__raw_writel(__raw_readl(gpio_reg_base + GPIO_CFG) & ~BIT(offset),
gpio_reg_base + GPIO_CFG);
spin_unlock_irqrestore(&gc->bgpio_lock, flags);
}
static int ls1x_gpio_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct gpio_chip *gc;
struct resource *res;
int ret;
gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL);
if (!gc)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
gpio_reg_base = devm_ioremap_resource(dev, res);
if (IS_ERR(gpio_reg_base))
return PTR_ERR(gpio_reg_base);
ret = bgpio_init(gc, dev, 4, gpio_reg_base + GPIO_DATA,
gpio_reg_base + GPIO_OUTPUT, NULL,
NULL, gpio_reg_base + GPIO_DIR, 0);
if (ret)
goto err;
gc->owner = THIS_MODULE;
gc->request = ls1x_gpio_request;
gc->free = ls1x_gpio_free;
gc->base = pdev->id * 32;
ret = devm_gpiochip_add_data(dev, gc, NULL);
if (ret)
goto err;
platform_set_drvdata(pdev, gc);
dev_info(dev, "Loongson1 GPIO driver registered\n");
return 0;
err:
dev_err(dev, "failed to register GPIO device\n");
return ret;
}
static struct platform_driver ls1x_gpio_driver = {
.probe = ls1x_gpio_probe,
.driver = {
.name = "ls1x-gpio",
},
};
module_platform_driver(ls1x_gpio_driver);
MODULE_AUTHOR("Kelvin Cheung <keguang.zhang@gmail.com>");
MODULE_DESCRIPTION("Loongson1 GPIO driver");
MODULE_LICENSE("GPL");
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