drivers/input/misc/ad714x-i2c.c

   1 /*
   2  * AD714X CapTouch Programmable Controller driver (I2C bus)
   3  *
   4  * Copyright 2009 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 #include "ad714x.h"
  15
  16 #ifdef CONFIG_PM
  17 static int ad714x_i2c_suspend(struct device *dev)
  18 {
  19         return ad714x_disable(i2c_get_clientdata(to_i2c_client(dev)));
  20 }
  21
  22 static int ad714x_i2c_resume(struct device *dev)
  23 {
  24         return ad714x_enable(i2c_get_clientdata(to_i2c_client(dev)));
  25 }
  26 #endif
  27
  28 static SIMPLE_DEV_PM_OPS(ad714x_i2c_pm, ad714x_i2c_suspend, ad714x_i2c_resume);
  29
  30 static int ad714x_i2c_write(struct device *dev, unsigned short reg,
  31                                 unsigned short data)
  32 {
  33         struct i2c_client *client = to_i2c_client(dev);
  34         int ret = 0;
  35         u8 *_reg = (u8 *)&reg;
  36         u8 *_data = (u8 *)&data;
  37
  38         u8 tx[4] = {
  39                 _reg[1],
  40                 _reg[0],
  41                 _data[1],
  42                 _data[0]
  43         };
  44
  45         ret = i2c_master_send(client, tx, 4);
  46         if (ret < 0)
  47                 dev_err(&client->dev, "I2C write error\n");
  48
  49         return ret;
  50 }
  51
  52 static int ad714x_i2c_read(struct device *dev, unsigned short reg,
  53                                 unsigned short *data)
  54 {
  55         struct i2c_client *client = to_i2c_client(dev);
  56         int ret = 0;
  57         u8 *_reg = (u8 *)&reg;
  58         u8 *_data = (u8 *)data;
  59
  60         u8 tx[2] = {
  61                 _reg[1],
  62                 _reg[0]
  63         };
  64         u8 rx[2];
  65
  66         ret = i2c_master_send(client, tx, 2);
  67         if (ret >= 0)
  68                 ret = i2c_master_recv(client, rx, 2);
  69
  70         if (unlikely(ret < 0)) {
  71                 dev_err(&client->dev, "I2C read error\n");
  72         } else {
  73                 _data[0] = rx[1];
  74                 _data[1] = rx[0];
  75         }
  76
  77         return ret;
  78 }
  79
  80 static int __devinit ad714x_i2c_probe(struct i2c_client *client,
  81                                         const struct i2c_device_id *id)
  82 {
  83         struct ad714x_chip *chip;
  84
  85         chip = ad714x_probe(&client->dev, BUS_I2C, client->irq,
  86                             ad714x_i2c_read, ad714x_i2c_write);
  87         if (IS_ERR(chip))
  88                 return PTR_ERR(chip);
  89
  90         i2c_set_clientdata(client, chip);
  91
  92         return 0;
  93 }
  94
  95 static int __devexit ad714x_i2c_remove(struct i2c_client *client)
  96 {
  97         struct ad714x_chip *chip = i2c_get_clientdata(client);
  98
  99         ad714x_remove(chip);
 100
 101         return 0;
 102 }
 103
 104 static const struct i2c_device_id ad714x_id[] = {
 105         { "ad7142_captouch", 0 },
 106         { "ad7143_captouch", 0 },
 107         { "ad7147_captouch", 0 },
 108         { "ad7147a_captouch", 0 },
 109         { "ad7148_captouch", 0 },
 110         { }
 111 };
 112 MODULE_DEVICE_TABLE(i2c, ad714x_id);
 113
 114 static struct i2c_driver ad714x_i2c_driver = {
 115         .driver = {
 116                 .name = "ad714x_captouch",
 117                 .pm   = &ad714x_i2c_pm,
 118         },
 119         .probe    = ad714x_i2c_probe,
 120         .remove   = __devexit_p(ad714x_i2c_remove),
 121         .id_table = ad714x_id,
 122 };
 123
 124 static __init int ad714x_i2c_init(void)
 125 {
 126         return i2c_add_driver(&ad714x_i2c_driver);
 127 }
 128 module_init(ad714x_i2c_init);
 129
 130 static __exit void ad714x_i2c_exit(void)
 131 {
 132         i2c_del_driver(&ad714x_i2c_driver);
 133 }
 134 module_exit(ad714x_i2c_exit);
 135
 136 MODULE_DESCRIPTION("Analog Devices AD714X Capacitance Touch Sensor I2C Bus Driver");
 137 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 138 MODULE_LICENSE("GPL");