1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun * GPIO Driver for Loongson 1 SoC
3*4882a593Smuzhiyun *
4*4882a593Smuzhiyun * Copyright (C) 2015-2016 Zhang, Keguang <keguang.zhang@gmail.com>
5*4882a593Smuzhiyun *
6*4882a593Smuzhiyun * This file is licensed under the terms of the GNU General Public
7*4882a593Smuzhiyun * License version 2. This program is licensed "as is" without any
8*4882a593Smuzhiyun * warranty of any kind, whether express or implied.
9*4882a593Smuzhiyun */
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun #include <linux/module.h>
12*4882a593Smuzhiyun #include <linux/gpio/driver.h>
13*4882a593Smuzhiyun #include <linux/platform_device.h>
14*4882a593Smuzhiyun #include <linux/bitops.h>
15*4882a593Smuzhiyun
16*4882a593Smuzhiyun /* Loongson 1 GPIO Register Definitions */
17*4882a593Smuzhiyun #define GPIO_CFG 0x0
18*4882a593Smuzhiyun #define GPIO_DIR 0x10
19*4882a593Smuzhiyun #define GPIO_DATA 0x20
20*4882a593Smuzhiyun #define GPIO_OUTPUT 0x30
21*4882a593Smuzhiyun
22*4882a593Smuzhiyun static void __iomem *gpio_reg_base;
23*4882a593Smuzhiyun
ls1x_gpio_request(struct gpio_chip * gc,unsigned int offset)24*4882a593Smuzhiyun static int ls1x_gpio_request(struct gpio_chip *gc, unsigned int offset)
25*4882a593Smuzhiyun {
26*4882a593Smuzhiyun unsigned long flags;
27*4882a593Smuzhiyun
28*4882a593Smuzhiyun spin_lock_irqsave(&gc->bgpio_lock, flags);
29*4882a593Smuzhiyun __raw_writel(__raw_readl(gpio_reg_base + GPIO_CFG) | BIT(offset),
30*4882a593Smuzhiyun gpio_reg_base + GPIO_CFG);
31*4882a593Smuzhiyun spin_unlock_irqrestore(&gc->bgpio_lock, flags);
32*4882a593Smuzhiyun
33*4882a593Smuzhiyun return 0;
34*4882a593Smuzhiyun }
35*4882a593Smuzhiyun
ls1x_gpio_free(struct gpio_chip * gc,unsigned int offset)36*4882a593Smuzhiyun static void ls1x_gpio_free(struct gpio_chip *gc, unsigned int offset)
37*4882a593Smuzhiyun {
38*4882a593Smuzhiyun unsigned long flags;
39*4882a593Smuzhiyun
40*4882a593Smuzhiyun spin_lock_irqsave(&gc->bgpio_lock, flags);
41*4882a593Smuzhiyun __raw_writel(__raw_readl(gpio_reg_base + GPIO_CFG) & ~BIT(offset),
42*4882a593Smuzhiyun gpio_reg_base + GPIO_CFG);
43*4882a593Smuzhiyun spin_unlock_irqrestore(&gc->bgpio_lock, flags);
44*4882a593Smuzhiyun }
45*4882a593Smuzhiyun
ls1x_gpio_probe(struct platform_device * pdev)46*4882a593Smuzhiyun static int ls1x_gpio_probe(struct platform_device *pdev)
47*4882a593Smuzhiyun {
48*4882a593Smuzhiyun struct device *dev = &pdev->dev;
49*4882a593Smuzhiyun struct gpio_chip *gc;
50*4882a593Smuzhiyun int ret;
51*4882a593Smuzhiyun
52*4882a593Smuzhiyun gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL);
53*4882a593Smuzhiyun if (!gc)
54*4882a593Smuzhiyun return -ENOMEM;
55*4882a593Smuzhiyun
56*4882a593Smuzhiyun gpio_reg_base = devm_platform_ioremap_resource(pdev, 0);
57*4882a593Smuzhiyun if (IS_ERR(gpio_reg_base))
58*4882a593Smuzhiyun return PTR_ERR(gpio_reg_base);
59*4882a593Smuzhiyun
60*4882a593Smuzhiyun ret = bgpio_init(gc, dev, 4, gpio_reg_base + GPIO_DATA,
61*4882a593Smuzhiyun gpio_reg_base + GPIO_OUTPUT, NULL,
62*4882a593Smuzhiyun NULL, gpio_reg_base + GPIO_DIR, 0);
63*4882a593Smuzhiyun if (ret)
64*4882a593Smuzhiyun goto err;
65*4882a593Smuzhiyun
66*4882a593Smuzhiyun gc->owner = THIS_MODULE;
67*4882a593Smuzhiyun gc->request = ls1x_gpio_request;
68*4882a593Smuzhiyun gc->free = ls1x_gpio_free;
69*4882a593Smuzhiyun gc->base = pdev->id * 32;
70*4882a593Smuzhiyun
71*4882a593Smuzhiyun ret = devm_gpiochip_add_data(dev, gc, NULL);
72*4882a593Smuzhiyun if (ret)
73*4882a593Smuzhiyun goto err;
74*4882a593Smuzhiyun
75*4882a593Smuzhiyun platform_set_drvdata(pdev, gc);
76*4882a593Smuzhiyun dev_info(dev, "Loongson1 GPIO driver registered\n");
77*4882a593Smuzhiyun
78*4882a593Smuzhiyun return 0;
79*4882a593Smuzhiyun err:
80*4882a593Smuzhiyun dev_err(dev, "failed to register GPIO device\n");
81*4882a593Smuzhiyun return ret;
82*4882a593Smuzhiyun }
83*4882a593Smuzhiyun
84*4882a593Smuzhiyun static struct platform_driver ls1x_gpio_driver = {
85*4882a593Smuzhiyun .probe = ls1x_gpio_probe,
86*4882a593Smuzhiyun .driver = {
87*4882a593Smuzhiyun .name = "ls1x-gpio",
88*4882a593Smuzhiyun },
89*4882a593Smuzhiyun };
90*4882a593Smuzhiyun
91*4882a593Smuzhiyun module_platform_driver(ls1x_gpio_driver);
92*4882a593Smuzhiyun
93*4882a593Smuzhiyun MODULE_AUTHOR("Kelvin Cheung <keguang.zhang@gmail.com>");
94*4882a593Smuzhiyun MODULE_DESCRIPTION("Loongson1 GPIO driver");
95*4882a593Smuzhiyun MODULE_LICENSE("GPL");
96