xref: /OK3568_Linux_fs/kernel/drivers/gpio/gpio-ts4800.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun  * GPIO driver for the TS-4800 board
3*4882a593Smuzhiyun  *
4*4882a593Smuzhiyun  * Copyright (c) 2016 - Savoir-faire Linux
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/gpio/driver.h>
12*4882a593Smuzhiyun #include <linux/module.h>
13*4882a593Smuzhiyun #include <linux/of_address.h>
14*4882a593Smuzhiyun #include <linux/of_device.h>
15*4882a593Smuzhiyun #include <linux/platform_device.h>
16*4882a593Smuzhiyun 
17*4882a593Smuzhiyun #define DEFAULT_PIN_NUMBER      16
18*4882a593Smuzhiyun #define INPUT_REG_OFFSET        0x00
19*4882a593Smuzhiyun #define OUTPUT_REG_OFFSET       0x02
20*4882a593Smuzhiyun #define DIRECTION_REG_OFFSET    0x04
21*4882a593Smuzhiyun 
ts4800_gpio_probe(struct platform_device * pdev)22*4882a593Smuzhiyun static int ts4800_gpio_probe(struct platform_device *pdev)
23*4882a593Smuzhiyun {
24*4882a593Smuzhiyun 	struct device_node *node;
25*4882a593Smuzhiyun 	struct gpio_chip *chip;
26*4882a593Smuzhiyun 	void __iomem *base_addr;
27*4882a593Smuzhiyun 	int retval;
28*4882a593Smuzhiyun 	u32 ngpios;
29*4882a593Smuzhiyun 
30*4882a593Smuzhiyun 	chip = devm_kzalloc(&pdev->dev, sizeof(struct gpio_chip), GFP_KERNEL);
31*4882a593Smuzhiyun 	if (!chip)
32*4882a593Smuzhiyun 		return -ENOMEM;
33*4882a593Smuzhiyun 
34*4882a593Smuzhiyun 	base_addr = devm_platform_ioremap_resource(pdev, 0);
35*4882a593Smuzhiyun 	if (IS_ERR(base_addr))
36*4882a593Smuzhiyun 		return PTR_ERR(base_addr);
37*4882a593Smuzhiyun 
38*4882a593Smuzhiyun 	node = pdev->dev.of_node;
39*4882a593Smuzhiyun 	if (!node)
40*4882a593Smuzhiyun 		return -EINVAL;
41*4882a593Smuzhiyun 
42*4882a593Smuzhiyun 	retval = of_property_read_u32(node, "ngpios", &ngpios);
43*4882a593Smuzhiyun 	if (retval == -EINVAL)
44*4882a593Smuzhiyun 		ngpios = DEFAULT_PIN_NUMBER;
45*4882a593Smuzhiyun 	else if (retval)
46*4882a593Smuzhiyun 		return retval;
47*4882a593Smuzhiyun 
48*4882a593Smuzhiyun 	retval = bgpio_init(chip, &pdev->dev, 2, base_addr + INPUT_REG_OFFSET,
49*4882a593Smuzhiyun 			    base_addr + OUTPUT_REG_OFFSET, NULL,
50*4882a593Smuzhiyun 			    base_addr + DIRECTION_REG_OFFSET, NULL, 0);
51*4882a593Smuzhiyun 	if (retval) {
52*4882a593Smuzhiyun 		dev_err(&pdev->dev, "bgpio_init failed\n");
53*4882a593Smuzhiyun 		return retval;
54*4882a593Smuzhiyun 	}
55*4882a593Smuzhiyun 
56*4882a593Smuzhiyun 	chip->ngpio = ngpios;
57*4882a593Smuzhiyun 
58*4882a593Smuzhiyun 	platform_set_drvdata(pdev, chip);
59*4882a593Smuzhiyun 
60*4882a593Smuzhiyun 	return devm_gpiochip_add_data(&pdev->dev, chip, NULL);
61*4882a593Smuzhiyun }
62*4882a593Smuzhiyun 
63*4882a593Smuzhiyun static const struct of_device_id ts4800_gpio_of_match[] = {
64*4882a593Smuzhiyun 	{ .compatible = "technologic,ts4800-gpio", },
65*4882a593Smuzhiyun 	{},
66*4882a593Smuzhiyun };
67*4882a593Smuzhiyun MODULE_DEVICE_TABLE(of, ts4800_gpio_of_match);
68*4882a593Smuzhiyun 
69*4882a593Smuzhiyun static struct platform_driver ts4800_gpio_driver = {
70*4882a593Smuzhiyun 	.driver = {
71*4882a593Smuzhiyun 		   .name = "ts4800-gpio",
72*4882a593Smuzhiyun 		   .of_match_table = ts4800_gpio_of_match,
73*4882a593Smuzhiyun 		   },
74*4882a593Smuzhiyun 	.probe = ts4800_gpio_probe,
75*4882a593Smuzhiyun };
76*4882a593Smuzhiyun 
77*4882a593Smuzhiyun module_platform_driver_probe(ts4800_gpio_driver, ts4800_gpio_probe);
78*4882a593Smuzhiyun 
79*4882a593Smuzhiyun MODULE_AUTHOR("Julien Grossholtz <julien.grossholtz@savoirfairelinux.com>");
80*4882a593Smuzhiyun MODULE_DESCRIPTION("TS4800 FPGA GPIO driver");
81*4882a593Smuzhiyun MODULE_LICENSE("GPL v2");
82