drivers/input/misc/ad714x-i2c.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * AD714X CapTouch Programmable Controller driver (I2C bus)
   4  *
   5  * Copyright 2009-2011 Analog Devices Inc.
   6  */
   7
   8 #include <linux/input.h>        /* BUS_I2C */
   9 #include <linux/i2c.h>
  10 #include <linux/module.h>
  11 #include <linux/types.h>
  12 #include <linux/pm.h>
  13 #include "ad714x.h"
  14
  15 static int ad714x_i2c_write(struct ad714x_chip *chip,
  16                             unsigned short reg, unsigned short data)
  17 {
  18         struct i2c_client *client = to_i2c_client(chip->dev);
  19         int error;
  20
  21         chip->xfer_buf[0] = cpu_to_be16(reg);
  22         chip->xfer_buf[1] = cpu_to_be16(data);
  23
  24         error = i2c_master_send(client, (u8 *)chip->xfer_buf,
  25                                 2 * sizeof(*chip->xfer_buf));
  26         if (unlikely(error < 0)) {
  27                 dev_err(&client->dev, "I2C write error: %d\n", error);
  28                 return error;
  29         }
  30
  31         return 0;
  32 }
  33
  34 static int ad714x_i2c_read(struct ad714x_chip *chip,
  35                            unsigned short reg, unsigned short *data, size_t len)
  36 {
  37         struct i2c_client *client = to_i2c_client(chip->dev);
  38         int i;
  39         int error;
  40
  41         chip->xfer_buf[0] = cpu_to_be16(reg);
  42
  43         error = i2c_master_send(client, (u8 *)chip->xfer_buf,
  44                                 sizeof(*chip->xfer_buf));
  45         if (error >= 0)
  46                 error = i2c_master_recv(client, (u8 *)chip->xfer_buf,
  47                                         len * sizeof(*chip->xfer_buf));
  48
  49         if (unlikely(error < 0)) {
  50                 dev_err(&client->dev, "I2C read error: %d\n", error);
  51                 return error;
  52         }
  53
  54         for (i = 0; i < len; i++)
  55                 data[i] = be16_to_cpu(chip->xfer_buf[i]);
  56
  57         return 0;
  58 }
  59
  60 static int ad714x_i2c_probe(struct i2c_client *client)
  61 {
  62         struct ad714x_chip *chip;
  63
  64         chip = ad714x_probe(&client->dev, BUS_I2C, client->irq,
  65                             ad714x_i2c_read, ad714x_i2c_write);
  66         if (IS_ERR(chip))
  67                 return PTR_ERR(chip);
  68
  69         i2c_set_clientdata(client, chip);
  70
  71         return 0;
  72 }
  73
  74 static const struct i2c_device_id ad714x_id[] = {
  75         { "ad7142_captouch" },
  76         { "ad7143_captouch" },
  77         { "ad7147_captouch" },
  78         { "ad7147a_captouch" },
  79         { "ad7148_captouch" },
  80         { }
  81 };
  82 MODULE_DEVICE_TABLE(i2c, ad714x_id);
  83
  84 static struct i2c_driver ad714x_i2c_driver = {
  85         .driver = {
  86                 .name = "ad714x_captouch",
  87                 .pm   = pm_sleep_ptr(&ad714x_pm),
  88         },
  89         .probe = ad714x_i2c_probe,
  90         .id_table = ad714x_id,
  91 };
  92
  93 module_i2c_driver(ad714x_i2c_driver);
  94
  95 MODULE_DESCRIPTION("Analog Devices AD714X Capacitance Touch Sensor I2C Bus Driver");
  96 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
  97 MODULE_LICENSE("GPL");