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// SPDX-License-Identifier: GPL-2.0-only
/*
* GPIO Driver for Loongson 1 SoC
*
* Copyright (C) 2015-2023 Keguang Zhang <keguang.zhang@gmail.com>
*/
#include <linux/bitops.h>
#include <linux/module.h>
#include <linux/gpio/driver.h>
#include <linux/gpio/generic.h>
#include <linux/platform_device.h>
/* Loongson 1 GPIO Register Definitions */
#define GPIO_CFG 0x0
#define GPIO_DIR 0x10
#define GPIO_DATA 0x20
#define GPIO_OUTPUT 0x30
struct ls1x_gpio_chip {
struct gpio_generic_chip chip;
void __iomem *reg_base;
};
static int ls1x_gpio_request(struct gpio_chip *gc, unsigned int offset)
{
struct ls1x_gpio_chip *ls1x_gc = gpiochip_get_data(gc);
guard(gpio_generic_lock_irqsave)(&ls1x_gc->chip);
__raw_writel(__raw_readl(ls1x_gc->reg_base + GPIO_CFG) | BIT(offset),
ls1x_gc->reg_base + GPIO_CFG);
return 0;
}
static void ls1x_gpio_free(struct gpio_chip *gc, unsigned int offset)
{
struct ls1x_gpio_chip *ls1x_gc = gpiochip_get_data(gc);
guard(gpio_generic_lock_irqsave)(&ls1x_gc->chip);
__raw_writel(__raw_readl(ls1x_gc->reg_base + GPIO_CFG) & ~BIT(offset),
ls1x_gc->reg_base + GPIO_CFG);
}
static int ls1x_gpio_probe(struct platform_device *pdev)
{
struct gpio_generic_chip_config config;
struct device *dev = &pdev->dev;
struct ls1x_gpio_chip *ls1x_gc;
int ret;
ls1x_gc = devm_kzalloc(dev, sizeof(*ls1x_gc), GFP_KERNEL);
if (!ls1x_gc)
return -ENOMEM;
ls1x_gc->reg_base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(ls1x_gc->reg_base))
return PTR_ERR(ls1x_gc->reg_base);
config = (struct gpio_generic_chip_config) {
.dev = dev,
.sz = 4,
.dat = ls1x_gc->reg_base + GPIO_DATA,
.set = ls1x_gc->reg_base + GPIO_OUTPUT,
.dirin = ls1x_gc->reg_base + GPIO_DIR,
};
ret = gpio_generic_chip_init(&ls1x_gc->chip, &config);
if (ret)
goto err;
ls1x_gc->chip.gc.owner = THIS_MODULE;
ls1x_gc->chip.gc.request = ls1x_gpio_request;
ls1x_gc->chip.gc.free = ls1x_gpio_free;
/*
* Clear ngpio to let gpiolib get the correct number
* by reading ngpios property
*/
ls1x_gc->chip.gc.ngpio = 0;
ret = devm_gpiochip_add_data(dev, &ls1x_gc->chip.gc, ls1x_gc);
if (ret)
goto err;
platform_set_drvdata(pdev, ls1x_gc);
dev_info(dev, "GPIO controller registered with %d pins\n",
ls1x_gc->chip.gc.ngpio);
return 0;
err:
dev_err(dev, "failed to register GPIO controller\n");
return ret;
}
static const struct of_device_id ls1x_gpio_dt_ids[] = {
{ .compatible = "loongson,ls1x-gpio" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, ls1x_gpio_dt_ids);
static struct platform_driver ls1x_gpio_driver = {
.probe = ls1x_gpio_probe,
.driver = {
.name = "ls1x-gpio",
.of_match_table = ls1x_gpio_dt_ids,
},
};
module_platform_driver(ls1x_gpio_driver);
MODULE_AUTHOR("Keguang Zhang <keguang.zhang@gmail.com>");
MODULE_DESCRIPTION("Loongson1 GPIO driver");
MODULE_LICENSE("GPL");
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