Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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/bitops.h>
9#include <linux/module.h>
10#include <linux/gpio/driver.h>
11#include <linux/gpio/generic.h>
12#include <linux/platform_device.h>
13
14/* Loongson 1 GPIO Register Definitions */
15#define GPIO_CFG 0x0
16#define GPIO_DIR 0x10
17#define GPIO_DATA 0x20
18#define GPIO_OUTPUT 0x30
19
20struct ls1x_gpio_chip {
21 struct gpio_generic_chip chip;
22 void __iomem *reg_base;
23};
24
25static int ls1x_gpio_request(struct gpio_chip *gc, unsigned int offset)
26{
27 struct ls1x_gpio_chip *ls1x_gc = gpiochip_get_data(gc);
28
29 guard(gpio_generic_lock_irqsave)(&ls1x_gc->chip);
30
31 __raw_writel(__raw_readl(ls1x_gc->reg_base + GPIO_CFG) | BIT(offset),
32 ls1x_gc->reg_base + GPIO_CFG);
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
41 guard(gpio_generic_lock_irqsave)(&ls1x_gc->chip);
42
43 __raw_writel(__raw_readl(ls1x_gc->reg_base + GPIO_CFG) & ~BIT(offset),
44 ls1x_gc->reg_base + GPIO_CFG);
45}
46
47static int ls1x_gpio_probe(struct platform_device *pdev)
48{
49 struct gpio_generic_chip_config config;
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 config = (struct gpio_generic_chip_config) {
63 .dev = dev,
64 .sz = 4,
65 .dat = ls1x_gc->reg_base + GPIO_DATA,
66 .set = ls1x_gc->reg_base + GPIO_OUTPUT,
67 .dirin = ls1x_gc->reg_base + GPIO_DIR,
68 };
69
70 ret = gpio_generic_chip_init(&ls1x_gc->chip, &config);
71 if (ret)
72 goto err;
73
74 ls1x_gc->chip.gc.owner = THIS_MODULE;
75 ls1x_gc->chip.gc.request = ls1x_gpio_request;
76 ls1x_gc->chip.gc.free = ls1x_gpio_free;
77 /*
78 * Clear ngpio to let gpiolib get the correct number
79 * by reading ngpios property
80 */
81 ls1x_gc->chip.gc.ngpio = 0;
82
83 ret = devm_gpiochip_add_data(dev, &ls1x_gc->chip.gc, ls1x_gc);
84 if (ret)
85 goto err;
86
87 platform_set_drvdata(pdev, ls1x_gc);
88
89 dev_info(dev, "GPIO controller registered with %d pins\n",
90 ls1x_gc->chip.gc.ngpio);
91
92 return 0;
93err:
94 dev_err(dev, "failed to register GPIO controller\n");
95 return ret;
96}
97
98static const struct of_device_id ls1x_gpio_dt_ids[] = {
99 { .compatible = "loongson,ls1x-gpio" },
100 { /* sentinel */ }
101};
102MODULE_DEVICE_TABLE(of, ls1x_gpio_dt_ids);
103
104static struct platform_driver ls1x_gpio_driver = {
105 .probe = ls1x_gpio_probe,
106 .driver = {
107 .name = "ls1x-gpio",
108 .of_match_table = ls1x_gpio_dt_ids,
109 },
110};
111
112module_platform_driver(ls1x_gpio_driver);
113
114MODULE_AUTHOR("Keguang Zhang <keguang.zhang@gmail.com>");
115MODULE_DESCRIPTION("Loongson1 GPIO driver");
116MODULE_LICENSE("GPL");