drivers/misc/ad525x_dpot-i2c.c

   1 /*
   2  * Driver for the Analog Devices digital potentiometers (I2C bus)
   3  *
   4  * Copyright (C) 2010 Michael Hennerich, Analog Devices Inc.
   5  *
   6  * Licensed under the GPL-2 or later.
   7  */
   8
   9 #include <linux/i2c.h>
  10 #include <linux/module.h>
  11
  12 #include "ad525x_dpot.h"
  13
  14 /* ------------------------------------------------------------------------- */
  15 /* I2C bus functions */
  16 static int write_d8(void *client, u8 val)
  17 {
  18         return i2c_smbus_write_byte(client, val);
  19 }
  20
  21 static int write_r8d8(void *client, u8 reg, u8 val)
  22 {
  23         return i2c_smbus_write_byte_data(client, reg, val);
  24 }
  25
  26 static int write_r8d16(void *client, u8 reg, u16 val)
  27 {
  28         return i2c_smbus_write_word_data(client, reg, val);
  29 }
  30
  31 static int read_d8(void *client)
  32 {
  33         return i2c_smbus_read_byte(client);
  34 }
  35
  36 static int read_r8d8(void *client, u8 reg)
  37 {
  38         return i2c_smbus_read_byte_data(client, reg);
  39 }
  40
  41 static int read_r8d16(void *client, u8 reg)
  42 {
  43         return i2c_smbus_read_word_data(client, reg);
  44 }
  45
  46 static const struct ad_dpot_bus_ops bops = {
  47         .read_d8        = read_d8,
  48         .read_r8d8      = read_r8d8,
  49         .read_r8d16     = read_r8d16,
  50         .write_d8       = write_d8,
  51         .write_r8d8     = write_r8d8,
  52         .write_r8d16    = write_r8d16,
  53 };
  54
  55 static int __devinit ad_dpot_i2c_probe(struct i2c_client *client,
  56                                       const struct i2c_device_id *id)
  57 {
  58         struct ad_dpot_bus_data bdata = {
  59                 .client = client,
  60                 .bops = &bops,
  61         };
  62
  63         struct ad_dpot_id dpot_id = {
  64                 .name = (char *) &id->name,
  65                 .devid = id->driver_data,
  66         };
  67
  68         if (!i2c_check_functionality(client->adapter,
  69                                      I2C_FUNC_SMBUS_WORD_DATA)) {
  70                 dev_err(&client->dev, "SMBUS Word Data not Supported\n");
  71                 return -EIO;
  72         }
  73
  74         return ad_dpot_probe(&client->dev, &bdata, &dpot_id);
  75 }
  76
  77 static int __devexit ad_dpot_i2c_remove(struct i2c_client *client)
  78 {
  79         return ad_dpot_remove(&client->dev);
  80 }
  81
  82 static const struct i2c_device_id ad_dpot_id[] = {
  83         {"ad5258", AD5258_ID},
  84         {"ad5259", AD5259_ID},
  85         {"ad5251", AD5251_ID},
  86         {"ad5252", AD5252_ID},
  87         {"ad5253", AD5253_ID},
  88         {"ad5254", AD5254_ID},
  89         {"ad5255", AD5255_ID},
  90         {}
  91 };
  92 MODULE_DEVICE_TABLE(i2c, ad_dpot_id);
  93
  94 static struct i2c_driver ad_dpot_i2c_driver = {
  95         .driver = {
  96                 .name   = "ad_dpot",
  97                 .owner  = THIS_MODULE,
  98         },
  99         .probe          = ad_dpot_i2c_probe,
 100         .remove         = __devexit_p(ad_dpot_i2c_remove),
 101         .id_table       = ad_dpot_id,
 102 };
 103
 104 static int __init ad_dpot_i2c_init(void)
 105 {
 106         return i2c_add_driver(&ad_dpot_i2c_driver);
 107 }
 108 module_init(ad_dpot_i2c_init);
 109
 110 static void __exit ad_dpot_i2c_exit(void)
 111 {
 112         i2c_del_driver(&ad_dpot_i2c_driver);
 113 }
 114 module_exit(ad_dpot_i2c_exit);
 115
 116 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 117 MODULE_DESCRIPTION("digital potentiometer I2C bus driver");
 118 MODULE_LICENSE("GPL");
 119 MODULE_ALIAS("i2c:ad_dpot");