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");
111