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.h>
11#include <linux/platform_device.h>
12
13#define DEFAULT_PIN_NUMBER 16
14#define INPUT_REG_OFFSET 0x00
15#define OUTPUT_REG_OFFSET 0x02
16#define DIRECTION_REG_OFFSET 0x04
17
18static int ts4800_gpio_probe(struct platform_device *pdev)
19{
20 struct device_node *node;
21 struct gpio_chip *chip;
22 void __iomem *base_addr;
23 int retval;
24 u32 ngpios;
25
26 chip = devm_kzalloc(dev: &pdev->dev, size: sizeof(struct gpio_chip), GFP_KERNEL);
27 if (!chip)
28 return -ENOMEM;
29
30 base_addr = devm_platform_ioremap_resource(pdev, index: 0);
31 if (IS_ERR(ptr: base_addr))
32 return PTR_ERR(ptr: base_addr);
33
34 node = pdev->dev.of_node;
35 if (!node)
36 return -EINVAL;
37
38 retval = of_property_read_u32(np: node, propname: "ngpios", out_value: &ngpios);
39 if (retval == -EINVAL)
40 ngpios = DEFAULT_PIN_NUMBER;
41 else if (retval)
42 return retval;
43
44 retval = bgpio_init(gc: chip, dev: &pdev->dev, sz: 2, dat: base_addr + INPUT_REG_OFFSET,
45 set: base_addr + OUTPUT_REG_OFFSET, NULL,
46 dirout: base_addr + DIRECTION_REG_OFFSET, NULL, flags: 0);
47 if (retval) {
48 dev_err(&pdev->dev, "bgpio_init failed\n");
49 return retval;
50 }
51
52 chip->ngpio = ngpios;
53
54 platform_set_drvdata(pdev, data: chip);
55
56 return devm_gpiochip_add_data(&pdev->dev, chip, NULL);
57}
58
59static const struct of_device_id ts4800_gpio_of_match[] = {
60 { .compatible = "technologic,ts4800-gpio", },
61 {},
62};
63MODULE_DEVICE_TABLE(of, ts4800_gpio_of_match);
64
65static struct platform_driver ts4800_gpio_driver = {
66 .driver = {
67 .name = "ts4800-gpio",
68 .of_match_table = ts4800_gpio_of_match,
69 },
70 .probe = ts4800_gpio_probe,
71};
72
73module_platform_driver_probe(ts4800_gpio_driver, ts4800_gpio_probe);
74
75MODULE_AUTHOR("Julien Grossholtz <julien.grossholtz@savoirfairelinux.com>");
76MODULE_DESCRIPTION("TS4800 FPGA GPIO driver");
77MODULE_LICENSE("GPL v2");
78

source code of linux/drivers/gpio/gpio-ts4800.c