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
  14 #include "ad7879.h"
  15
  16 #define AD7879_DEVID            0x79    /* AD7879-1/AD7889-1 */
  17
  18 #ifdef CONFIG_PM
  19 static int ad7879_i2c_suspend(struct i2c_client *client, pm_message_t message)
  20 {
  21         struct ad7879 *ts = i2c_get_clientdata(client);
  22
  23         ad7879_suspend(ts);
  24
  25         return 0;
  26 }
  27
  28 static int ad7879_i2c_resume(struct i2c_client *client)
  29 {
  30         struct ad7879 *ts = i2c_get_clientdata(client);
  31
  32         ad7879_resume(ts);
  33
  34         return 0;
  35 }
  36 #else
  37 # define ad7879_i2c_suspend NULL
  38 # define ad7879_i2c_resume  NULL
  39 #endif
  40
  41 /* All registers are word-sized.
  42  * AD7879 uses a high-byte first convention.
  43  */
  44 static int ad7879_i2c_read(struct device *dev, u8 reg)
  45 {
  46         struct i2c_client *client = to_i2c_client(dev);
  47
  48         return swab16(i2c_smbus_read_word_data(client, reg));
  49 }
  50
  51 static int ad7879_i2c_multi_read(struct device *dev,
  52                                  u8 first_reg, u8 count, u16 *buf)
  53 {
  54         struct i2c_client *client = to_i2c_client(dev);
  55         u8 idx;
  56
  57         i2c_smbus_read_i2c_block_data(client, first_reg, count * 2, (u8 *)buf);
  58
  59         for (idx = 0; idx < count; ++idx)
  60                 buf[idx] = swab16(buf[idx]);
  61
  62         return 0;
  63 }
  64
  65 static int ad7879_i2c_write(struct device *dev, u8 reg, u16 val)
  66 {
  67         struct i2c_client *client = to_i2c_client(dev);
  68
  69         return i2c_smbus_write_word_data(client, reg, swab16(val));
  70 }
  71
  72 static const struct ad7879_bus_ops ad7879_i2c_bus_ops = {
  73         .bustype        = BUS_I2C,
  74         .read           = ad7879_i2c_read,
  75         .multi_read     = ad7879_i2c_multi_read,
  76         .write          = ad7879_i2c_write,
  77 };
  78
  79 static int __devinit ad7879_i2c_probe(struct i2c_client *client,
  80                                       const struct i2c_device_id *id)
  81 {
  82         struct ad7879 *ts;
  83
  84         if (!i2c_check_functionality(client->adapter,
  85                                      I2C_FUNC_SMBUS_WORD_DATA)) {
  86                 dev_err(&client->dev, "SMBUS Word Data not Supported\n");
  87                 return -EIO;
  88         }
  89
  90         ts = ad7879_probe(&client->dev, AD7879_DEVID, client->irq,
  91                           &ad7879_i2c_bus_ops);
  92         if (IS_ERR(ts))
  93                 return PTR_ERR(ts);
  94
  95         i2c_set_clientdata(client, ts);
  96
  97         return 0;
  98 }
  99
 100 static int __devexit ad7879_i2c_remove(struct i2c_client *client)
 101 {
 102         struct ad7879 *ts = i2c_get_clientdata(client);
 103
 104         ad7879_remove(ts);
 105
 106         return 0;
 107 }
 108
 109 static const struct i2c_device_id ad7879_id[] = {
 110         { "ad7879", 0 },
 111         { "ad7889", 0 },
 112         { }
 113 };
 114 MODULE_DEVICE_TABLE(i2c, ad7879_id);
 115
 116 static struct i2c_driver ad7879_i2c_driver = {
 117         .driver = {
 118                 .name   = "ad7879",
 119                 .owner  = THIS_MODULE,
 120         },
 121         .probe          = ad7879_i2c_probe,
 122         .remove         = __devexit_p(ad7879_i2c_remove),
 123         .suspend        = ad7879_i2c_suspend,
 124         .resume         = ad7879_i2c_resume,
 125         .id_table       = ad7879_id,
 126 };
 127
 128 static int __init ad7879_i2c_init(void)
 129 {
 130         return i2c_add_driver(&ad7879_i2c_driver);
 131 }
 132 module_init(ad7879_i2c_init);
 133
 134 static void __exit ad7879_i2c_exit(void)
 135 {
 136         i2c_del_driver(&ad7879_i2c_driver);
 137 }
 138 module_exit(ad7879_i2c_exit);
 139
 140 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 141 MODULE_DESCRIPTION("AD7879(-1) touchscreen I2C bus driver");
 142 MODULE_LICENSE("GPL");
 143 MODULE_ALIAS("i2c:ad7879");