tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * GPIO driver for the TS-4800 board
4 *
5 * Copyright (c) 2016 - Savoir-faire Linux
6 */
7
8#include <linux/gpio/driver.h>
9#include <linux/module.h>
10#include <linux/of_address.h>
11#include <linux/of_device.h>
12#include <linux/platform_device.h>
13
14#define DEFAULT_PIN_NUMBER 16
15#define INPUT_REG_OFFSET 0x00
16#define OUTPUT_REG_OFFSET 0x02
17#define DIRECTION_REG_OFFSET 0x04
18
19static int ts4800_gpio_probe(struct platform_device *pdev)
20{
21 struct device_node *node;
22 struct gpio_chip *chip;
23 void __iomem *base_addr;
24 int retval;
25 u32 ngpios;
26
27 chip = devm_kzalloc(&pdev->dev, sizeof(struct gpio_chip), GFP_KERNEL);
28 if (!chip)
29 return -ENOMEM;
30
31 base_addr = devm_platform_ioremap_resource(pdev, 0);
32 if (IS_ERR(base_addr))
33 return PTR_ERR(base_addr);
34
35 node = pdev->dev.of_node;
36 if (!node)
37 return -EINVAL;
38
39 retval = of_property_read_u32(node, "ngpios", &ngpios);
40 if (retval == -EINVAL)
41 ngpios = DEFAULT_PIN_NUMBER;
42 else if (retval)
43 return retval;
44
45 retval = bgpio_init(chip, &pdev->dev, 2, base_addr + INPUT_REG_OFFSET,
46 base_addr + OUTPUT_REG_OFFSET, NULL,
47 base_addr + DIRECTION_REG_OFFSET, NULL, 0);
48 if (retval) {
49 dev_err(&pdev->dev, "bgpio_init failed\n");
50 return retval;
51 }
52
53 chip->ngpio = ngpios;
54
55 platform_set_drvdata(pdev, chip);
56
57 return devm_gpiochip_add_data(&pdev->dev, chip, NULL);
58}
59
60static const struct of_device_id ts4800_gpio_of_match[] = {
61 { .compatible = "technologic,ts4800-gpio", },
62 {},
63};
64MODULE_DEVICE_TABLE(of, ts4800_gpio_of_match);
65
66static struct platform_driver ts4800_gpio_driver = {
67 .driver = {
68 .name = "ts4800-gpio",
69 .of_match_table = ts4800_gpio_of_match,
70 },
71 .probe = ts4800_gpio_probe,
72};
73
74module_platform_driver_probe(ts4800_gpio_driver, ts4800_gpio_probe);
75
76MODULE_AUTHOR("Julien Grossholtz <julien.grossholtz@savoirfairelinux.com>");
77MODULE_DESCRIPTION("TS4800 FPGA GPIO driver");
78MODULE_LICENSE("GPL v2");