1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2023 Analog Devices, Inc.
4 * Driver for the DS4520 I/O Expander
5 */
6
7 #include <linux/device.h>
8 #include <linux/gpio/driver.h>
9 #include <linux/gpio/regmap.h>
10 #include <linux/i2c.h>
11 #include <linux/property.h>
12 #include <linux/regmap.h>
13
14 #define DS4520_PULLUP0 0xF0
15 #define DS4520_IO_CONTROL0 0xF2
16 #define DS4520_IO_STATUS0 0xF8
17
18 static const struct regmap_config ds4520_regmap_config = {
19 .reg_bits = 8,
20 .val_bits = 8,
21 };
22
ds4520_gpio_probe(struct i2c_client * client)23 static int ds4520_gpio_probe(struct i2c_client *client)
24 {
25 struct gpio_regmap_config config = { };
26 struct device *dev = &client->dev;
27 struct regmap *regmap;
28 u32 ngpio;
29 u32 base;
30 int ret;
31
32 ret = device_property_read_u32(dev, "reg", &base);
33 if (ret)
34 return dev_err_probe(dev, ret, "Missing 'reg' property.\n");
35
36 ret = device_property_read_u32(dev, "ngpios", &ngpio);
37 if (ret)
38 return dev_err_probe(dev, ret, "Missing 'ngpios' property.\n");
39
40 regmap = devm_regmap_init_i2c(client, &ds4520_regmap_config);
41 if (IS_ERR(regmap))
42 return dev_err_probe(dev, PTR_ERR(regmap),
43 "Failed to allocate register map\n");
44
45 config.regmap = regmap;
46 config.parent = dev;
47 config.ngpio = ngpio;
48
49 config.reg_dat_base = base + DS4520_IO_STATUS0;
50 config.reg_set_base = base + DS4520_PULLUP0;
51 config.reg_dir_out_base = base + DS4520_IO_CONTROL0;
52
53 return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(dev, &config));
54 }
55
56 static const struct of_device_id ds4520_gpio_of_match_table[] = {
57 { .compatible = "adi,ds4520-gpio" },
58 { }
59 };
60 MODULE_DEVICE_TABLE(of, ds4520_gpio_of_match_table);
61
62 static const struct i2c_device_id ds4520_gpio_id_table[] = {
63 { "ds4520-gpio" },
64 { }
65 };
66 MODULE_DEVICE_TABLE(i2c, ds4520_gpio_id_table);
67
68 static struct i2c_driver ds4520_gpio_driver = {
69 .driver = {
70 .name = "ds4520-gpio",
71 .of_match_table = ds4520_gpio_of_match_table,
72 },
73 .probe = ds4520_gpio_probe,
74 .id_table = ds4520_gpio_id_table,
75 };
76 module_i2c_driver(ds4520_gpio_driver);
77
78 MODULE_DESCRIPTION("DS4520 I/O Expander");
79 MODULE_AUTHOR("Okan Sahin <okan.sahin@analog.com>");
80 MODULE_LICENSE("GPL");
81