blob: 10c09bdd851430c9ef7de0b1114711cbd40e6c39 [file] [log] [blame]
Kelvin Cheungbd37c992016-04-06 20:34:53 +08001/*
2 * GPIO Driver for Loongson 1 SoC
3 *
4 * Copyright (C) 2015-2016 Zhang, Keguang <keguang.zhang@gmail.com>
5 *
6 * This file is licensed under the terms of the GNU General Public
7 * License version 2. This program is licensed "as is" without any
8 * warranty of any kind, whether express or implied.
9 */
10
11#include <linux/gpio/driver.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
20static void __iomem *gpio_reg_base;
21
22static int ls1x_gpio_request(struct gpio_chip *gc, unsigned int offset)
23{
24 unsigned long pinmask = gc->pin2mask(gc, offset);
25 unsigned long flags;
26
27 spin_lock_irqsave(&gc->bgpio_lock, flags);
28 __raw_writel(__raw_readl(gpio_reg_base + GPIO_CFG) | pinmask,
29 gpio_reg_base + GPIO_CFG);
30 spin_unlock_irqrestore(&gc->bgpio_lock, flags);
31
32 return 0;
33}
34
35static void ls1x_gpio_free(struct gpio_chip *gc, unsigned int offset)
36{
37 unsigned long pinmask = gc->pin2mask(gc, offset);
38 unsigned long flags;
39
40 spin_lock_irqsave(&gc->bgpio_lock, flags);
41 __raw_writel(__raw_readl(gpio_reg_base + GPIO_CFG) & ~pinmask,
42 gpio_reg_base + GPIO_CFG);
43 spin_unlock_irqrestore(&gc->bgpio_lock, flags);
44}
45
46static int ls1x_gpio_probe(struct platform_device *pdev)
47{
48 struct device *dev = &pdev->dev;
49 struct gpio_chip *gc;
50 struct resource *res;
51 int ret;
52
53 gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL);
54 if (!gc)
55 return -ENOMEM;
56
57 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
58 if (!res) {
59 dev_err(dev, "failed to get I/O memory\n");
60 return -EINVAL;
61 }
62
63 gpio_reg_base = devm_ioremap_resource(dev, res);
64 if (IS_ERR(gpio_reg_base))
65 return PTR_ERR(gpio_reg_base);
66
67 ret = bgpio_init(gc, dev, 4, gpio_reg_base + GPIO_DATA,
68 gpio_reg_base + GPIO_OUTPUT, NULL,
69 NULL, gpio_reg_base + GPIO_DIR, 0);
70 if (ret)
71 goto err;
72
73 gc->owner = THIS_MODULE;
74 gc->request = ls1x_gpio_request;
75 gc->free = ls1x_gpio_free;
76 gc->base = pdev->id * 32;
77
78 ret = devm_gpiochip_add_data(dev, gc, NULL);
79 if (ret)
80 goto err;
81
82 platform_set_drvdata(pdev, gc);
83 dev_info(dev, "Loongson1 GPIO driver registered\n");
84
85 return 0;
86err:
87 dev_err(dev, "failed to register GPIO device\n");
88 return ret;
89}
90
91static struct platform_driver ls1x_gpio_driver = {
92 .probe = ls1x_gpio_probe,
93 .driver = {
94 .name = "ls1x-gpio",
95 },
96};
97
98module_platform_driver(ls1x_gpio_driver);
99
100MODULE_AUTHOR("Kelvin Cheung <keguang.zhang@gmail.com>");
101MODULE_DESCRIPTION("Loongson1 GPIO driver");
102MODULE_LICENSE("GPL");