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 base;
29 int ret;
30
31 ret = device_property_read_u32(dev, "reg", &base);
32 if (ret)
33 return dev_err_probe(dev, ret, "Missing 'reg' property.\n");
34
35 regmap = devm_regmap_init_i2c(client, &ds4520_regmap_config);
36 if (IS_ERR(regmap))
37 return dev_err_probe(dev, PTR_ERR(regmap),
38 "Failed to allocate register map\n");
39
40 config.regmap = regmap;
41 config.parent = dev;
42
43 config.reg_dat_base = base + DS4520_IO_STATUS0;
44 config.reg_set_base = base + DS4520_PULLUP0;
45 config.reg_dir_out_base = base + DS4520_IO_CONTROL0;
46
47 return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(dev, &config));
48 }
49
50 static const struct of_device_id ds4520_gpio_of_match_table[] = {
51 { .compatible = "adi,ds4520-gpio" },
52 { }
53 };
54 MODULE_DEVICE_TABLE(of, ds4520_gpio_of_match_table);
55
56 static const struct i2c_device_id ds4520_gpio_id_table[] = {
57 { "ds4520-gpio" },
58 { }
59 };
60 MODULE_DEVICE_TABLE(i2c, ds4520_gpio_id_table);
61
62 static struct i2c_driver ds4520_gpio_driver = {
63 .driver = {
64 .name = "ds4520-gpio",
65 .of_match_table = ds4520_gpio_of_match_table,
66 },
67 .probe = ds4520_gpio_probe,
68 .id_table = ds4520_gpio_id_table,
69 };
70 module_i2c_driver(ds4520_gpio_driver);
71
72 MODULE_DESCRIPTION("DS4520 I/O Expander");
73 MODULE_AUTHOR("Okan Sahin <okan.sahin@analog.com>");
74 MODULE_LICENSE("GPL");
75