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"); 58