1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Simple MFD - I2C
4 *
5 * Author(s):
6 * Michael Walle <michael@walle.cc>
7 * Lee Jones <lee.jones@linaro.org>
8 *
9 * This driver creates a single register map with the intention for it to be
10 * shared by all sub-devices. Children can use their parent's device structure
11 * (dev.parent) in order to reference it.
12 *
13 * Once the register map has been successfully initialised, any sub-devices
14 * represented by child nodes in Device Tree or via the MFD cells in this file
15 * will be subsequently registered.
16 */
17
18 #include <linux/i2c.h>
19 #include <linux/kernel.h>
20 #include <linux/mfd/core.h>
21 #include <linux/module.h>
22 #include <linux/of_platform.h>
23 #include <linux/regmap.h>
24
25 #include "simple-mfd-i2c.h"
26
27 static const struct regmap_config regmap_config_8r_8v = {
28 .reg_bits = 8,
29 .val_bits = 8,
30 };
31
simple_mfd_i2c_probe(struct i2c_client * i2c)32 static int simple_mfd_i2c_probe(struct i2c_client *i2c)
33 {
34 const struct simple_mfd_data *simple_mfd_data;
35 const struct regmap_config *regmap_config;
36 struct regmap *regmap;
37 int ret;
38
39 simple_mfd_data = device_get_match_data(&i2c->dev);
40
41 /* If no regmap_config is specified, use the default 8reg and 8val bits */
42 if (!simple_mfd_data || !simple_mfd_data->regmap_config)
43 regmap_config = ®map_config_8r_8v;
44 else
45 regmap_config = simple_mfd_data->regmap_config;
46
47 regmap = devm_regmap_init_i2c(i2c, regmap_config);
48 if (IS_ERR(regmap))
49 return PTR_ERR(regmap);
50
51 /* If no MFD cells are specified, register using the DT child nodes instead */
52 if (!simple_mfd_data || !simple_mfd_data->mfd_cell)
53 return devm_of_platform_populate(&i2c->dev);
54
55 ret = devm_mfd_add_devices(&i2c->dev, PLATFORM_DEVID_AUTO,
56 simple_mfd_data->mfd_cell,
57 simple_mfd_data->mfd_cell_size,
58 NULL, 0, NULL);
59 if (ret)
60 dev_err(&i2c->dev, "Failed to add child devices\n");
61
62 return ret;
63 }
64
65 static const struct mfd_cell sy7636a_cells[] = {
66 { .name = "sy7636a-regulator", },
67 { .name = "sy7636a-temperature", },
68 };
69
70 static const struct simple_mfd_data silergy_sy7636a = {
71 .mfd_cell = sy7636a_cells,
72 .mfd_cell_size = ARRAY_SIZE(sy7636a_cells),
73 };
74
75 static const struct mfd_cell max5970_cells[] = {
76 { .name = "max5970-regulator", },
77 { .name = "max5970-iio", },
78 { .name = "max5970-led", },
79 };
80
81 static const struct simple_mfd_data maxim_max5970 = {
82 .mfd_cell = max5970_cells,
83 .mfd_cell_size = ARRAY_SIZE(max5970_cells),
84 };
85
86 static const struct of_device_id simple_mfd_i2c_of_match[] = {
87 { .compatible = "kontron,sl28cpld" },
88 { .compatible = "silergy,sy7636a", .data = &silergy_sy7636a},
89 { .compatible = "maxim,max5970", .data = &maxim_max5970},
90 { .compatible = "maxim,max5978", .data = &maxim_max5970},
91 {}
92 };
93 MODULE_DEVICE_TABLE(of, simple_mfd_i2c_of_match);
94
95 static struct i2c_driver simple_mfd_i2c_driver = {
96 .probe = simple_mfd_i2c_probe,
97 .driver = {
98 .name = "simple-mfd-i2c",
99 .of_match_table = simple_mfd_i2c_of_match,
100 },
101 };
102 module_i2c_driver(simple_mfd_i2c_driver);
103
104 MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
105 MODULE_DESCRIPTION("Simple MFD - I2C driver");
106 MODULE_LICENSE("GPL v2");
107