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 static int __maybe_unused ad714x_i2c_suspend(struct device *dev)
  17 {
  18         return ad714x_disable(i2c_get_clientdata(to_i2c_client(dev)));
  19 }
  20
  21 static int __maybe_unused ad714x_i2c_resume(struct device *dev)
  22 {
  23         return ad714x_enable(i2c_get_clientdata(to_i2c_client(dev)));
  24 }
  25
  26 static SIMPLE_DEV_PM_OPS(ad714x_i2c_pm, ad714x_i2c_suspend, ad714x_i2c_resume);
  27
  28 static int ad714x_i2c_write(struct ad714x_chip *chip,
  29                             unsigned short reg, unsigned short data)
  30 {
  31         struct i2c_client *client = to_i2c_client(chip->dev);
  32         int error;
  33
  34         chip->xfer_buf[0] = cpu_to_be16(reg);
  35         chip->xfer_buf[1] = cpu_to_be16(data);
  36
  37         error = i2c_master_send(client, (u8 *)chip->xfer_buf,
  38                                 2 * sizeof(*chip->xfer_buf));
  39         if (unlikely(error < 0)) {
  40                 dev_err(&client->dev, "I2C write error: %d\n", error);
  41                 return error;
  42         }
  43
  44         return 0;
  45 }
  46
  47 static int ad714x_i2c_read(struct ad714x_chip *chip,
  48                            unsigned short reg, unsigned short *data, size_t len)
  49 {
  50         struct i2c_client *client = to_i2c_client(chip->dev);
  51         int i;
  52         int error;
  53
  54         chip->xfer_buf[0] = cpu_to_be16(reg);
  55
  56         error = i2c_master_send(client, (u8 *)chip->xfer_buf,
  57                                 sizeof(*chip->xfer_buf));
  58         if (error >= 0)
  59                 error = i2c_master_recv(client, (u8 *)chip->xfer_buf,
  60                                         len * sizeof(*chip->xfer_buf));
  61
  62         if (unlikely(error < 0)) {
  63                 dev_err(&client->dev, "I2C read error: %d\n", error);
  64                 return error;
  65         }
  66
  67         for (i = 0; i < len; i++)
  68                 data[i] = be16_to_cpu(chip->xfer_buf[i]);
  69
  70         return 0;
  71 }
  72
  73 static int ad714x_i2c_probe(struct i2c_client *client,
  74                                         const struct i2c_device_id *id)
  75 {
  76         struct ad714x_chip *chip;
  77
  78         chip = ad714x_probe(&client->dev, BUS_I2C, client->irq,
  79                             ad714x_i2c_read, ad714x_i2c_write);
  80         if (IS_ERR(chip))
  81                 return PTR_ERR(chip);
  82
  83         i2c_set_clientdata(client, chip);
  84
  85         return 0;
  86 }
  87
  88 static const struct i2c_device_id ad714x_id[] = {
  89         { "ad7142_captouch", 0 },
  90         { "ad7143_captouch", 0 },
  91         { "ad7147_captouch", 0 },
  92         { "ad7147a_captouch", 0 },
  93         { "ad7148_captouch", 0 },
  94         { }
  95 };
  96 MODULE_DEVICE_TABLE(i2c, ad714x_id);
  97
  98 static struct i2c_driver ad714x_i2c_driver = {
  99         .driver = {
 100                 .name = "ad714x_captouch",
 101                 .pm   = &ad714x_i2c_pm,
 102         },
 103         .probe    = ad714x_i2c_probe,
 104         .id_table = ad714x_id,
 105 };
 106
 107 module_i2c_driver(ad714x_i2c_driver);
 108
 109 MODULE_DESCRIPTION("Analog Devices AD714X Capacitance Touch Sensor I2C Bus Driver");
 110 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 111 MODULE_LICENSE("GPL");