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 #ifdef CONFIG_PM
  20 static int ad7879_i2c_suspend(struct device *dev)
  21 {
  22         struct i2c_client *client = to_i2c_client(dev);
  23         struct ad7879 *ts = i2c_get_clientdata(client);
  24
  25         ad7879_suspend(ts);
  26
  27         return 0;
  28 }
  29
  30 static int ad7879_i2c_resume(struct device *dev)
  31 {
  32         struct i2c_client *client = to_i2c_client(dev);
  33         struct ad7879 *ts = i2c_get_clientdata(client);
  34
  35         ad7879_resume(ts);
  36
  37         return 0;
  38 }
  39
  40 static SIMPLE_DEV_PM_OPS(ad7879_i2c_pm, ad7879_i2c_suspend, ad7879_i2c_resume);
  41 #endif
  42
  43 /* All registers are word-sized.
  44  * AD7879 uses a high-byte first convention.
  45  */
  46 static int ad7879_i2c_read(struct device *dev, u8 reg)
  47 {
  48         struct i2c_client *client = to_i2c_client(dev);
  49
  50         return swab16(i2c_smbus_read_word_data(client, reg));
  51 }
  52
  53 static int ad7879_i2c_multi_read(struct device *dev,
  54                                  u8 first_reg, u8 count, u16 *buf)
  55 {
  56         struct i2c_client *client = to_i2c_client(dev);
  57         u8 idx;
  58
  59         i2c_smbus_read_i2c_block_data(client, first_reg, count * 2, (u8 *)buf);
  60
  61         for (idx = 0; idx < count; ++idx)
  62                 buf[idx] = swab16(buf[idx]);
  63
  64         return 0;
  65 }
  66
  67 static int ad7879_i2c_write(struct device *dev, u8 reg, u16 val)
  68 {
  69         struct i2c_client *client = to_i2c_client(dev);
  70
  71         return i2c_smbus_write_word_data(client, reg, swab16(val));
  72 }
  73
  74 static const struct ad7879_bus_ops ad7879_i2c_bus_ops = {
  75         .bustype        = BUS_I2C,
  76         .read           = ad7879_i2c_read,
  77         .multi_read     = ad7879_i2c_multi_read,
  78         .write          = ad7879_i2c_write,
  79 };
  80
  81 static int __devinit ad7879_i2c_probe(struct i2c_client *client,
  82                                       const struct i2c_device_id *id)
  83 {
  84         struct ad7879 *ts;
  85
  86         if (!i2c_check_functionality(client->adapter,
  87                                      I2C_FUNC_SMBUS_WORD_DATA)) {
  88                 dev_err(&client->dev, "SMBUS Word Data not Supported\n");
  89                 return -EIO;
  90         }
  91
  92         ts = ad7879_probe(&client->dev, AD7879_DEVID, client->irq,
  93                           &ad7879_i2c_bus_ops);
  94         if (IS_ERR(ts))
  95                 return PTR_ERR(ts);
  96
  97         i2c_set_clientdata(client, ts);
  98
  99         return 0;
 100 }
 101
 102 static int __devexit ad7879_i2c_remove(struct i2c_client *client)
 103 {
 104         struct ad7879 *ts = i2c_get_clientdata(client);
 105
 106         ad7879_remove(ts);
 107
 108         return 0;
 109 }
 110
 111 static const struct i2c_device_id ad7879_id[] = {
 112         { "ad7879", 0 },
 113         { "ad7889", 0 },
 114         { }
 115 };
 116 MODULE_DEVICE_TABLE(i2c, ad7879_id);
 117
 118 static struct i2c_driver ad7879_i2c_driver = {
 119         .driver = {
 120                 .name   = "ad7879",
 121                 .owner  = THIS_MODULE,
 122 #ifdef CONFIG_PM
 123                 .pm     = &ad7879_i2c_pm,
 124 #endif
 125         },
 126         .probe          = ad7879_i2c_probe,
 127         .remove         = __devexit_p(ad7879_i2c_remove),
 128         .id_table       = ad7879_id,
 129 };
 130
 131 static int __init ad7879_i2c_init(void)
 132 {
 133         return i2c_add_driver(&ad7879_i2c_driver);
 134 }
 135 module_init(ad7879_i2c_init);
 136
 137 static void __exit ad7879_i2c_exit(void)
 138 {
 139         i2c_del_driver(&ad7879_i2c_driver);
 140 }
 141 module_exit(ad7879_i2c_exit);
 142
 143 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 144 MODULE_DESCRIPTION("AD7879(-1) touchscreen I2C bus driver");
 145 MODULE_LICENSE("GPL");
 146 MODULE_ALIAS("i2c:ad7879");