drivers/mfd/simple-mfd-i2c.c

   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
  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 = &regmap_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 spedified, use register 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 of_device_id simple_mfd_i2c_of_match[] = {
  76         { .compatible = "kontron,sl28cpld" },
  77         { .compatible = "silergy,sy7636a", .data = &silergy_sy7636a},
  78         {}
  79 };
  80 MODULE_DEVICE_TABLE(of, simple_mfd_i2c_of_match);
  81
  82 static struct i2c_driver simple_mfd_i2c_driver = {
  83         .probe_new = simple_mfd_i2c_probe,
  84         .driver = {
  85                 .name = "simple-mfd-i2c",
  86                 .of_match_table = simple_mfd_i2c_of_match,
  87         },
  88 };
  89 module_i2c_driver(simple_mfd_i2c_driver);
  90
  91 MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
  92 MODULE_DESCRIPTION("Simple MFD - I2C driver");
  93 MODULE_LICENSE("GPL v2");