drivers/input/misc/ad714x-i2c.c

   1 /*
   2  * AD714X CapTouch Programmable Controller driver (I2C bus)
   3  *
   4  * Copyright 2009-2011 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 ad714x_chip *chip,
  31                             unsigned short reg, unsigned short data)
  32 {
  33         struct i2c_client *client = to_i2c_client(chip->dev);
  34         int error;
  35
  36         chip->xfer_buf[0] = cpu_to_be16(reg);
  37         chip->xfer_buf[1] = cpu_to_be16(data);
  38
  39         error = i2c_master_send(client, (u8 *)chip->xfer_buf,
  40                                 2 * sizeof(*chip->xfer_buf));
  41         if (unlikely(error < 0)) {
  42                 dev_err(&client->dev, "I2C write error: %d\n", error);
  43                 return error;
  44         }
  45
  46         return 0;
  47 }
  48
  49 static int ad714x_i2c_read(struct ad714x_chip *chip,
  50                            unsigned short reg, unsigned short *data, size_t len)
  51 {
  52         struct i2c_client *client = to_i2c_client(chip->dev);
  53         int i;
  54         int error;
  55
  56         chip->xfer_buf[0] = cpu_to_be16(reg);
  57
  58         error = i2c_master_send(client, (u8 *)chip->xfer_buf,
  59                                 sizeof(*chip->xfer_buf));
  60         if (error >= 0)
  61                 error = i2c_master_recv(client, (u8 *)chip->xfer_buf,
  62                                         len * sizeof(*chip->xfer_buf));
  63
  64         if (unlikely(error < 0)) {
  65                 dev_err(&client->dev, "I2C read error: %d\n", error);
  66                 return error;
  67         }
  68
  69         for (i = 0; i < len; i++)
  70                 data[i] = be16_to_cpu(chip->xfer_buf[i]);
  71
  72         return 0;
  73 }
  74
  75 static int ad714x_i2c_probe(struct i2c_client *client,
  76                                         const struct i2c_device_id *id)
  77 {
  78         struct ad714x_chip *chip;
  79
  80         chip = ad714x_probe(&client->dev, BUS_I2C, client->irq,
  81                             ad714x_i2c_read, ad714x_i2c_write);
  82         if (IS_ERR(chip))
  83                 return PTR_ERR(chip);
  84
  85         i2c_set_clientdata(client, chip);
  86
  87         return 0;
  88 }
  89
  90 static int ad714x_i2c_remove(struct i2c_client *client)
  91 {
  92         struct ad714x_chip *chip = i2c_get_clientdata(client);
  93
  94         ad714x_remove(chip);
  95
  96         return 0;
  97 }
  98
  99 static const struct i2c_device_id ad714x_id[] = {
 100         { "ad7142_captouch", 0 },
 101         { "ad7143_captouch", 0 },
 102         { "ad7147_captouch", 0 },
 103         { "ad7147a_captouch", 0 },
 104         { "ad7148_captouch", 0 },
 105         { }
 106 };
 107 MODULE_DEVICE_TABLE(i2c, ad714x_id);
 108
 109 static struct i2c_driver ad714x_i2c_driver = {
 110         .driver = {
 111                 .name = "ad714x_captouch",
 112                 .pm   = &ad714x_i2c_pm,
 113         },
 114         .probe    = ad714x_i2c_probe,
 115         .remove   = ad714x_i2c_remove,
 116         .id_table = ad714x_id,
 117 };
 118
 119 module_i2c_driver(ad714x_i2c_driver);
 120
 121 MODULE_DESCRIPTION("Analog Devices AD714X Capacitance Touch Sensor I2C Bus Driver");
 122 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 123 MODULE_LICENSE("GPL");