1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Simple MFD - I2C
4 *
5 * This driver creates a single register map with the intention for it to be
6 * shared by all sub-devices.  Children can use their parent's device structure
7 * (dev.parent) in order to reference it.
8 *
9 * Once the register map has been successfully initialised, any sub-devices
10 * represented by child nodes in Device Tree will be subsequently registered.
11 */
12
13#include <linux/i2c.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/of_platform.h>
17#include <linux/regmap.h>
18
19static const struct regmap_config simple_regmap_config = {
20	.reg_bits = 8,
21	.val_bits = 8,
22};
23
24static int simple_mfd_i2c_probe(struct i2c_client *i2c)
25{
26	const struct regmap_config *config;
27	struct regmap *regmap;
28
29	config = device_get_match_data(&i2c->dev);
30	if (!config)
31		config = &simple_regmap_config;
32
33	regmap = devm_regmap_init_i2c(i2c, config);
34	if (IS_ERR(regmap))
35		return PTR_ERR(regmap);
36
37	return devm_of_platform_populate(&i2c->dev);
38}
39
40static const struct of_device_id simple_mfd_i2c_of_match[] = {
41	{ .compatible = "kontron,sl28cpld" },
42	{}
43};
44MODULE_DEVICE_TABLE(of, simple_mfd_i2c_of_match);
45
46static struct i2c_driver simple_mfd_i2c_driver = {
47	.probe_new = simple_mfd_i2c_probe,
48	.driver = {
49		.name = "simple-mfd-i2c",
50		.of_match_table = simple_mfd_i2c_of_match,
51	},
52};
53module_i2c_driver(simple_mfd_i2c_driver);
54
55MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
56MODULE_DESCRIPTION("Simple MFD - I2C driver");
57MODULE_LICENSE("GPL v2");
58