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 | |
19 | struct ls1x_gpio_chip { |
20 | struct gpio_chip gc; |
21 | void __iomem *reg_base; |
22 | }; |
23 | |
24 | static 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 | |
37 | static 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 | |
48 | static 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; |
87 | err: |
88 | dev_err(dev, "failed to register GPIO controller\n" ); |
89 | return ret; |
90 | } |
91 | |
92 | static const struct of_device_id ls1x_gpio_dt_ids[] = { |
93 | { .compatible = "loongson,ls1x-gpio" }, |
94 | { /* sentinel */ } |
95 | }; |
96 | MODULE_DEVICE_TABLE(of, ls1x_gpio_dt_ids); |
97 | |
98 | static 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 | |
106 | module_platform_driver(ls1x_gpio_driver); |
107 | |
108 | MODULE_AUTHOR("Keguang Zhang <keguang.zhang@gmail.com>" ); |
109 | MODULE_DESCRIPTION("Loongson1 GPIO driver" ); |
110 | MODULE_LICENSE("GPL" ); |
111 | |