1/*
2 * GPIO driver for the TS-4800 board
3 *
4 * Copyright (c) 2016 - Savoir-faire Linux
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/module.h>
13#include <linux/of_address.h>
14#include <linux/of_device.h>
15#include <linux/platform_device.h>
16
17#define DEFAULT_PIN_NUMBER 16
18#define INPUT_REG_OFFSET 0x00
19#define OUTPUT_REG_OFFSET 0x02
20#define DIRECTION_REG_OFFSET 0x04
21
22static int ts4800_gpio_probe(struct platform_device *pdev)
23{
24 struct device_node *node;
25 struct gpio_chip *chip;
26 struct resource *res;
27 void __iomem *base_addr;
28 int retval;
29 u32 ngpios;
30
31 chip = devm_kzalloc(&pdev->dev, sizeof(struct gpio_chip), GFP_KERNEL);
32 if (!chip)
33 return -ENOMEM;
34
35 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
36 base_addr = devm_ioremap_resource(&pdev->dev, res);
37 if (IS_ERR(base_addr))
38 return PTR_ERR(base_addr);
39
40 node = pdev->dev.of_node;
41 if (!node)
42 return -EINVAL;
43
44 retval = of_property_read_u32(node, "ngpios", &ngpios);
45 if (retval == -EINVAL)
46 ngpios = DEFAULT_PIN_NUMBER;
47 else if (retval)
48 return retval;
49
50 retval = bgpio_init(chip, &pdev->dev, 2, base_addr + INPUT_REG_OFFSET,
51 base_addr + OUTPUT_REG_OFFSET, NULL,
52 base_addr + DIRECTION_REG_OFFSET, NULL, 0);
53 if (retval) {
54 dev_err(&pdev->dev, "bgpio_init failed\n");
55 return retval;
56 }
57
58 chip->ngpio = ngpios;
59
60 platform_set_drvdata(pdev, chip);
61
62 return devm_gpiochip_add_data(&pdev->dev, chip, NULL);
63}
64
65static const struct of_device_id ts4800_gpio_of_match[] = {
66 { .compatible = "technologic,ts4800-gpio", },
67 {},
68};
69MODULE_DEVICE_TABLE(of, ts4800_gpio_of_match);
70
71static struct platform_driver ts4800_gpio_driver = {
72 .driver = {
73 .name = "ts4800-gpio",
74 .of_match_table = ts4800_gpio_of_match,
75 },
76 .probe = ts4800_gpio_probe,
77};
78
79module_platform_driver_probe(ts4800_gpio_driver, ts4800_gpio_probe);
80
81MODULE_AUTHOR("Julien Grossholtz <julien.grossholtz@savoirfairelinux.com>");
82MODULE_DESCRIPTION("TS4800 FPGA GPIO driver");
83MODULE_LICENSE("GPL v2");
84