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 | |
18 | static 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 | |
59 | static const struct of_device_id ts4800_gpio_of_match[] = { |
60 | { .compatible = "technologic,ts4800-gpio" , }, |
61 | {}, |
62 | }; |
63 | MODULE_DEVICE_TABLE(of, ts4800_gpio_of_match); |
64 | |
65 | static 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 | |
73 | module_platform_driver_probe(ts4800_gpio_driver, ts4800_gpio_probe); |
74 | |
75 | MODULE_AUTHOR("Julien Grossholtz <julien.grossholtz@savoirfairelinux.com>" ); |
76 | MODULE_DESCRIPTION("TS4800 FPGA GPIO driver" ); |
77 | MODULE_LICENSE("GPL v2" ); |
78 | |