xref: /openbmc/linux/drivers/gpio/gpio-ds4520.c (revision 659ad5f7)
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