drivers/mfd/simple-mfd-i2c.c

   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
  19 static const struct regmap_config simple_regmap_config = {
  20         .reg_bits = 8,
  21         .val_bits = 8,
  22 };
  23
  24 static 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
  40 static const struct of_device_id simple_mfd_i2c_of_match[] = {
  41         { .compatible = "kontron,sl28cpld" },
  42         {}
  43 };
  44 MODULE_DEVICE_TABLE(of, simple_mfd_i2c_of_match);
  45
  46 static 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 };
  53 module_i2c_driver(simple_mfd_i2c_driver);
  54
  55 MODULE_AUTHOR("Michael Walle <michael@walle.cc>");
  56 MODULE_DESCRIPTION("Simple MFD - I2C driver");
  57 MODULE_LICENSE("GPL v2");