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/of.h>
  14 #include <linux/pm.h>
  15
  16 #include "ad7879.h"
  17
  18 #define AD7879_DEVID            0x79    /* AD7879-1/AD7889-1 */
  19
  20 /* All registers are word-sized.
  21  * AD7879 uses a high-byte first convention.
  22  */
  23 static int ad7879_i2c_read(struct device *dev, u8 reg)
  24 {
  25         struct i2c_client *client = to_i2c_client(dev);
  26
  27         return i2c_smbus_read_word_swapped(client, reg);
  28 }
  29
  30 static int ad7879_i2c_multi_read(struct device *dev,
  31                                  u8 first_reg, u8 count, u16 *buf)
  32 {
  33         struct i2c_client *client = to_i2c_client(dev);
  34         u8 idx;
  35
  36         i2c_smbus_read_i2c_block_data(client, first_reg, count * 2, (u8 *)buf);
  37
  38         for (idx = 0; idx < count; ++idx)
  39                 buf[idx] = swab16(buf[idx]);
  40
  41         return 0;
  42 }
  43
  44 static int ad7879_i2c_write(struct device *dev, u8 reg, u16 val)
  45 {
  46         struct i2c_client *client = to_i2c_client(dev);
  47
  48         return i2c_smbus_write_word_swapped(client, reg, val);
  49 }
  50
  51 static const struct ad7879_bus_ops ad7879_i2c_bus_ops = {
  52         .bustype        = BUS_I2C,
  53         .read           = ad7879_i2c_read,
  54         .multi_read     = ad7879_i2c_multi_read,
  55         .write          = ad7879_i2c_write,
  56 };
  57
  58 static int ad7879_i2c_probe(struct i2c_client *client,
  59                                       const struct i2c_device_id *id)
  60 {
  61         struct ad7879 *ts;
  62
  63         if (!i2c_check_functionality(client->adapter,
  64                                      I2C_FUNC_SMBUS_WORD_DATA)) {
  65                 dev_err(&client->dev, "SMBUS Word Data not Supported\n");
  66                 return -EIO;
  67         }
  68
  69         ts = ad7879_probe(&client->dev, AD7879_DEVID, client->irq,
  70                           &ad7879_i2c_bus_ops);
  71         if (IS_ERR(ts))
  72                 return PTR_ERR(ts);
  73
  74         i2c_set_clientdata(client, ts);
  75
  76         return 0;
  77 }
  78
  79 static int ad7879_i2c_remove(struct i2c_client *client)
  80 {
  81         struct ad7879 *ts = i2c_get_clientdata(client);
  82
  83         ad7879_remove(ts);
  84
  85         return 0;
  86 }
  87
  88 static const struct i2c_device_id ad7879_id[] = {
  89         { "ad7879", 0 },
  90         { "ad7889", 0 },
  91         { }
  92 };
  93 MODULE_DEVICE_TABLE(i2c, ad7879_id);
  94
  95 #ifdef CONFIG_OF
  96 static const struct of_device_id ad7879_i2c_dt_ids[] = {
  97         { .compatible = "adi,ad7879-1", },
  98         { }
  99 };
 100 MODULE_DEVICE_TABLE(of, ad7879_i2c_dt_ids);
 101 #endif
 102
 103 static struct i2c_driver ad7879_i2c_driver = {
 104         .driver = {
 105                 .name   = "ad7879",
 106                 .pm     = &ad7879_pm_ops,
 107                 .of_match_table = of_match_ptr(ad7879_i2c_dt_ids),
 108         },
 109         .probe          = ad7879_i2c_probe,
 110         .remove         = ad7879_i2c_remove,
 111         .id_table       = ad7879_id,
 112 };
 113
 114 module_i2c_driver(ad7879_i2c_driver);
 115
 116 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 117 MODULE_DESCRIPTION("AD7879(-1) touchscreen I2C bus driver");
 118 MODULE_LICENSE("GPL");