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(&pdev->dev, sizeof(struct gpio_chip), GFP_KERNEL);
27	if (!chip)
28		return -ENOMEM;
29
30	base_addr = devm_platform_ioremap_resource(pdev, 0);
31	if (IS_ERR(base_addr))
32		return PTR_ERR(base_addr);
33
34	node = pdev->dev.of_node;
35	if (!node)
36		return -EINVAL;
37
38	retval = of_property_read_u32(node, "ngpios", &ngpios);
39	if (retval == -EINVAL)
40		ngpios = DEFAULT_PIN_NUMBER;
41	else if (retval)
42		return retval;
43
44	retval = bgpio_init(chip, &pdev->dev, 2, base_addr + INPUT_REG_OFFSET,
45			    base_addr + OUTPUT_REG_OFFSET, NULL,
46			    base_addr + DIRECTION_REG_OFFSET, NULL, 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, 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