drivers/input/touchscreen/ad7879-i2c.c

   1 /*
   2  * AD7879-1/AD7889-1 touchscreen (I2C bus)
   3  *
   4  * Copyright (C) 2008-2010 Michael Hennerich, Analog Devices Inc.
   5  *
   6  * Licensed under the GPL-2 or later.
   7  */
   8
   9 #include <linux/input.h>        /* BUS_I2C */
  10 #include <linux/i2c.h>
  11 #include <linux/module.h>
  12 #include <linux/types.h>
  13 #include <linux/pm.h>
  14
  15 #include "ad7879.h"
  16
  17 #define AD7879_DEVID            0x79    /* AD7879-1/AD7889-1 */
  18
  19 /* All registers are word-sized.
  20  * AD7879 uses a high-byte first convention.
  21  */
  22 static int ad7879_i2c_read(struct device *dev, u8 reg)
  23 {
  24         struct i2c_client *client = to_i2c_client(dev);
  25
  26         return i2c_smbus_read_word_swapped(client, reg);
  27 }
  28
  29 static int ad7879_i2c_multi_read(struct device *dev,
  30                                  u8 first_reg, u8 count, u16 *buf)
  31 {
  32         struct i2c_client *client = to_i2c_client(dev);
  33         u8 idx;
  34
  35         i2c_smbus_read_i2c_block_data(client, first_reg, count * 2, (u8 *)buf);
  36
  37         for (idx = 0; idx < count; ++idx)
  38                 buf[idx] = swab16(buf[idx]);
  39
  40         return 0;
  41 }
  42
  43 static int ad7879_i2c_write(struct device *dev, u8 reg, u16 val)
  44 {
  45         struct i2c_client *client = to_i2c_client(dev);
  46
  47         return i2c_smbus_write_word_swapped(client, reg, val);
  48 }
  49
  50 static const struct ad7879_bus_ops ad7879_i2c_bus_ops = {
  51         .bustype        = BUS_I2C,
  52         .read           = ad7879_i2c_read,
  53         .multi_read     = ad7879_i2c_multi_read,
  54         .write          = ad7879_i2c_write,
  55 };
  56
  57 static int ad7879_i2c_probe(struct i2c_client *client,
  58                                       const struct i2c_device_id *id)
  59 {
  60         struct ad7879 *ts;
  61
  62         if (!i2c_check_functionality(client->adapter,
  63                                      I2C_FUNC_SMBUS_WORD_DATA)) {
  64                 dev_err(&client->dev, "SMBUS Word Data not Supported\n");
  65                 return -EIO;
  66         }
  67
  68         ts = ad7879_probe(&client->dev, AD7879_DEVID, client->irq,
  69                           &ad7879_i2c_bus_ops);
  70         if (IS_ERR(ts))
  71                 return PTR_ERR(ts);
  72
  73         i2c_set_clientdata(client, ts);
  74
  75         return 0;
  76 }
  77
  78 static int ad7879_i2c_remove(struct i2c_client *client)
  79 {
  80         struct ad7879 *ts = i2c_get_clientdata(client);
  81
  82         ad7879_remove(ts);
  83
  84         return 0;
  85 }
  86
  87 static const struct i2c_device_id ad7879_id[] = {
  88         { "ad7879", 0 },
  89         { "ad7889", 0 },
  90         { }
  91 };
  92 MODULE_DEVICE_TABLE(i2c, ad7879_id);
  93
  94 static struct i2c_driver ad7879_i2c_driver = {
  95         .driver = {
  96                 .name   = "ad7879",
  97                 .pm     = &ad7879_pm_ops,
  98         },
  99         .probe          = ad7879_i2c_probe,
 100         .remove         = ad7879_i2c_remove,
 101         .id_table       = ad7879_id,
 102 };
 103
 104 module_i2c_driver(ad7879_i2c_driver);
 105
 106 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 107 MODULE_DESCRIPTION("AD7879(-1) touchscreen I2C bus driver");
 108 MODULE_LICENSE("GPL");