1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * GPIO Driver for Loongson 1 SoC
  4 *
  5 * Copyright (C) 2015-2023 Keguang Zhang <keguang.zhang@gmail.com>
  6 */
  7
  8#include <linux/module.h>
  9#include <linux/gpio/driver.h>
 10#include <linux/platform_device.h>
 11#include <linux/bitops.h>
 12
 13/* Loongson 1 GPIO Register Definitions */
 14#define GPIO_CFG		0x0
 15#define GPIO_DIR		0x10
 16#define GPIO_DATA		0x20
 17#define GPIO_OUTPUT		0x30
 18
 19struct ls1x_gpio_chip {
 20	struct gpio_chip gc;
 21	void __iomem *reg_base;
 22};
 23
 24static int ls1x_gpio_request(struct gpio_chip *gc, unsigned int offset)
 25{
 26	struct ls1x_gpio_chip *ls1x_gc = gpiochip_get_data(gc);
 27	unsigned long flags;
 28
 29	raw_spin_lock_irqsave(&gc->bgpio_lock, flags);
 30	__raw_writel(__raw_readl(ls1x_gc->reg_base + GPIO_CFG) | BIT(offset),
 31		     ls1x_gc->reg_base + GPIO_CFG);
 32	raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);
 33
 34	return 0;
 35}
 36
 37static void ls1x_gpio_free(struct gpio_chip *gc, unsigned int offset)
 38{
 39	struct ls1x_gpio_chip *ls1x_gc = gpiochip_get_data(gc);
 40	unsigned long flags;
 41
 42	raw_spin_lock_irqsave(&gc->bgpio_lock, flags);
 43	__raw_writel(__raw_readl(ls1x_gc->reg_base + GPIO_CFG) & ~BIT(offset),
 44		     ls1x_gc->reg_base + GPIO_CFG);
 45	raw_spin_unlock_irqrestore(&gc->bgpio_lock, flags);
 46}
 47
 48static int ls1x_gpio_probe(struct platform_device *pdev)
 49{
 50	struct device *dev = &pdev->dev;
 51	struct ls1x_gpio_chip *ls1x_gc;
 52	int ret;
 53
 54	ls1x_gc = devm_kzalloc(dev, sizeof(*ls1x_gc), GFP_KERNEL);
 55	if (!ls1x_gc)
 56		return -ENOMEM;
 57
 58	ls1x_gc->reg_base = devm_platform_ioremap_resource(pdev, 0);
 59	if (IS_ERR(ls1x_gc->reg_base))
 60		return PTR_ERR(ls1x_gc->reg_base);
 61
 62	ret = bgpio_init(&ls1x_gc->gc, dev, 4, ls1x_gc->reg_base + GPIO_DATA,
 63			 ls1x_gc->reg_base + GPIO_OUTPUT, NULL,
 64			 NULL, ls1x_gc->reg_base + GPIO_DIR, 0);
 65	if (ret)
 66		goto err;
 67
 68	ls1x_gc->gc.owner = THIS_MODULE;
 69	ls1x_gc->gc.request = ls1x_gpio_request;
 70	ls1x_gc->gc.free = ls1x_gpio_free;
 71	/*
 72	 * Clear ngpio to let gpiolib get the correct number
 73	 * by reading ngpios property
 74	 */
 75	ls1x_gc->gc.ngpio = 0;
 76
 77	ret = devm_gpiochip_add_data(dev, &ls1x_gc->gc, ls1x_gc);
 78	if (ret)
 79		goto err;
 80
 81	platform_set_drvdata(pdev, ls1x_gc);
 82
 83	dev_info(dev, "GPIO controller registered with %d pins\n",
 84		 ls1x_gc->gc.ngpio);
 85
 86	return 0;
 87err:
 88	dev_err(dev, "failed to register GPIO controller\n");
 89	return ret;
 90}
 91
 92static const struct of_device_id ls1x_gpio_dt_ids[] = {
 93	{ .compatible = "loongson,ls1x-gpio" },
 94	{ /* sentinel */ }
 95};
 96MODULE_DEVICE_TABLE(of, ls1x_gpio_dt_ids);
 97
 98static struct platform_driver ls1x_gpio_driver = {
 99	.probe	= ls1x_gpio_probe,
100	.driver	= {
101		.name	= "ls1x-gpio",
102		.of_match_table = ls1x_gpio_dt_ids,
103	},
104};
105
106module_platform_driver(ls1x_gpio_driver);
107
108MODULE_AUTHOR("Keguang Zhang <keguang.zhang@gmail.com>");
109MODULE_DESCRIPTION("Loongson1 GPIO driver");
110MODULE_LICENSE("GPL");