1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* GPIO driver for the TS-4800 board
*
* Copyright (c) 2016 - Savoir-faire Linux
*/
#include <linux/gpio/driver.h>
#include <linux/gpio/generic.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#define DEFAULT_PIN_NUMBER 16
#define INPUT_REG_OFFSET 0x00
#define OUTPUT_REG_OFFSET 0x02
#define DIRECTION_REG_OFFSET 0x04
static int ts4800_gpio_probe(struct platform_device *pdev)
{
struct gpio_generic_chip_config config;
struct device *dev = &pdev->dev;
struct gpio_generic_chip *chip;
void __iomem *base_addr;
int retval;
u32 ngpios;
chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
if (!chip)
return -ENOMEM;
base_addr = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(base_addr))
return PTR_ERR(base_addr);
retval = device_property_read_u32(dev, "ngpios", &ngpios);
if (retval == -EINVAL)
ngpios = DEFAULT_PIN_NUMBER;
else if (retval)
return retval;
config = (struct gpio_generic_chip_config) {
.dev = dev,
.sz = 2,
.dat = base_addr + INPUT_REG_OFFSET,
.set = base_addr + OUTPUT_REG_OFFSET,
.dirout = base_addr + DIRECTION_REG_OFFSET,
};
retval = gpio_generic_chip_init(chip, &config);
if (retval)
return dev_err_probe(dev, retval,
"failed to initialize the generic GPIO chip\n");
chip->gc.ngpio = ngpios;
return devm_gpiochip_add_data(dev, &chip->gc, NULL);
}
static const struct of_device_id ts4800_gpio_of_match[] = {
{ .compatible = "technologic,ts4800-gpio", },
{},
};
MODULE_DEVICE_TABLE(of, ts4800_gpio_of_match);
static struct platform_driver ts4800_gpio_driver = {
.driver = {
.name = "ts4800-gpio",
.of_match_table = ts4800_gpio_of_match,
},
.probe = ts4800_gpio_probe,
};
module_platform_driver_probe(ts4800_gpio_driver, ts4800_gpio_probe);
MODULE_AUTHOR("Julien Grossholtz <julien.grossholtz@savoirfairelinux.com>");
MODULE_DESCRIPTION("TS4800 FPGA GPIO driver");
MODULE_LICENSE("GPL v2");
|
