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 "ad714x.h"
  14
  15 #ifdef CONFIG_PM
  16 static int ad714x_i2c_suspend(struct i2c_client *client, pm_message_t message)
  17 {
  18         return ad714x_disable(i2c_get_clientdata(client));
  19 }
  20
  21 static int ad714x_i2c_resume(struct i2c_client *client)
  22 {
  23         return ad714x_enable(i2c_get_clientdata(client));
  24 }
  25 #else
  26 # define ad714x_i2c_suspend NULL
  27 # define ad714x_i2c_resume  NULL
  28 #endif
  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         },
 118         .probe    = ad714x_i2c_probe,
 119         .remove   = __devexit_p(ad714x_i2c_remove),
 120         .suspend  = ad714x_i2c_suspend,
 121         .resume   = ad714x_i2c_resume,
 122         .id_table = ad714x_id,
 123 };
 124
 125 static __init int ad714x_i2c_init(void)
 126 {
 127         return i2c_add_driver(&ad714x_i2c_driver);
 128 }
 129 module_init(ad714x_i2c_init);
 130
 131 static __exit void ad714x_i2c_exit(void)
 132 {
 133         i2c_del_driver(&ad714x_i2c_driver);
 134 }
 135 module_exit(ad714x_i2c_exit);
 136
 137 MODULE_DESCRIPTION("Analog Devices AD714X Capacitance Touch Sensor I2C Bus Driver");
 138 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 139 MODULE_LICENSE("GPL");