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_disable(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_enable(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         u8 idx;
  55
  56         for (idx = 0; idx < count; ++idx)
  57                 buf[idx] = ad7879_i2c_read(dev, first_reg + idx);
  58
  59         return 0;
  60 }
  61
  62 static int ad7879_i2c_write(struct device *dev, u8 reg, u16 val)
  63 {
  64         struct i2c_client *client = to_i2c_client(dev);
  65
  66         return i2c_smbus_write_word_data(client, reg, swab16(val));
  67 }
  68
  69 static const struct ad7879_bus_ops ad7879_i2c_bus_ops = {
  70         .bustype        = BUS_I2C,
  71         .read           = ad7879_i2c_read,
  72         .multi_read     = ad7879_i2c_multi_read,
  73         .write          = ad7879_i2c_write,
  74 };
  75
  76 static int __devinit ad7879_i2c_probe(struct i2c_client *client,
  77                                       const struct i2c_device_id *id)
  78 {
  79         struct ad7879 *ts;
  80
  81         if (!i2c_check_functionality(client->adapter,
  82                                      I2C_FUNC_SMBUS_WORD_DATA)) {
  83                 dev_err(&client->dev, "SMBUS Word Data not Supported\n");
  84                 return -EIO;
  85         }
  86
  87         ts = ad7879_probe(&client->dev, AD7879_DEVID, client->irq,
  88                           &ad7879_i2c_bus_ops);
  89         if (IS_ERR(ts))
  90                 return PTR_ERR(ts);
  91
  92         i2c_set_clientdata(client, ts);
  93
  94         return 0;
  95 }
  96
  97 static int __devexit ad7879_i2c_remove(struct i2c_client *client)
  98 {
  99         struct ad7879 *ts = i2c_get_clientdata(client);
 100
 101         ad7879_remove(ts);
 102
 103         return 0;
 104 }
 105
 106 static const struct i2c_device_id ad7879_id[] = {
 107         { "ad7879", 0 },
 108         { "ad7889", 0 },
 109         { }
 110 };
 111 MODULE_DEVICE_TABLE(i2c, ad7879_id);
 112
 113 static struct i2c_driver ad7879_i2c_driver = {
 114         .driver = {
 115                 .name   = "ad7879",
 116                 .owner  = THIS_MODULE,
 117         },
 118         .probe          = ad7879_i2c_probe,
 119         .remove         = __devexit_p(ad7879_i2c_remove),
 120         .suspend        = ad7879_i2c_suspend,
 121         .resume         = ad7879_i2c_resume,
 122         .id_table       = ad7879_id,
 123 };
 124
 125 static int __init ad7879_i2c_init(void)
 126 {
 127         return i2c_add_driver(&ad7879_i2c_driver);
 128 }
 129 module_init(ad7879_i2c_init);
 130
 131 static void __exit ad7879_i2c_exit(void)
 132 {
 133         i2c_del_driver(&ad7879_i2c_driver);
 134 }
 135 module_exit(ad7879_i2c_exit);
 136
 137 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 138 MODULE_DESCRIPTION("AD7879(-1) touchscreen I2C bus driver");
 139 MODULE_LICENSE("GPL");
 140 MODULE_ALIAS("i2c:ad7879");