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(addr: ls1x_gc->reg_base + GPIO_CFG) | BIT(offset),
31 addr: 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(addr: ls1x_gc->reg_base + GPIO_CFG) & ~BIT(offset),
44 addr: 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, size: sizeof(*ls1x_gc), GFP_KERNEL);
55 if (!ls1x_gc)
56 return -ENOMEM;
57
58 ls1x_gc->reg_base = devm_platform_ioremap_resource(pdev, index: 0);
59 if (IS_ERR(ptr: ls1x_gc->reg_base))
60 return PTR_ERR(ptr: ls1x_gc->reg_base);
61
62 ret = bgpio_init(gc: &ls1x_gc->gc, dev, sz: 4, dat: ls1x_gc->reg_base + GPIO_DATA,
63 set: ls1x_gc->reg_base + GPIO_OUTPUT, NULL,
64 NULL, dirin: ls1x_gc->reg_base + GPIO_DIR, flags: 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, data: 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

source code of linux/drivers/gpio/gpio-loongson1.c