LXR linux/drivers/input/misc/ad714x-spi.c

   1/*
   2 * AD714X CapTouch Programmable Controller driver (SPI 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/module.h>
  11#include <linux/spi/spi.h>
  12#include <linux/pm.h>
  13#include <linux/types.h>
  14#include "ad714x.h"
  15
  16#define AD714x_SPI_CMD_PREFIX      0xE000   /* bits 15:11 */
  17#define AD714x_SPI_READ            BIT(10)
  18
  19#ifdef CONFIG_PM
  20static int ad714x_spi_suspend(struct device *dev)
  21{
  22        return ad714x_disable(spi_get_drvdata(to_spi_device(dev)));
  23}
  24
  25static int ad714x_spi_resume(struct device *dev)
  26{
  27        return ad714x_enable(spi_get_drvdata(to_spi_device(dev)));
  28}
  29#endif
  30
  31static SIMPLE_DEV_PM_OPS(ad714x_spi_pm, ad714x_spi_suspend, ad714x_spi_resume);
  32
  33static int ad714x_spi_read(struct device *dev, unsigned short reg,
  34                unsigned short *data)
  35{
  36        struct spi_device *spi = to_spi_device(dev);
  37        unsigned short tx = AD714x_SPI_CMD_PREFIX | AD714x_SPI_READ | reg;
  38
  39        return spi_write_then_read(spi, (u8 *)&tx, 2, (u8 *)data, 2);
  40}
  41
  42static int ad714x_spi_write(struct device *dev, unsigned short reg,
  43                unsigned short data)
  44{
  45        struct spi_device *spi = to_spi_device(dev);
  46        unsigned short tx[2] = {
  47                AD714x_SPI_CMD_PREFIX | reg,
  48                data
  49        };
  50
  51        return spi_write(spi, (u8 *)tx, 4);
  52}
  53
  54static int __devinit ad714x_spi_probe(struct spi_device *spi)
  55{
  56        struct ad714x_chip *chip;
  57
  58        chip = ad714x_probe(&spi->dev, BUS_SPI, spi->irq,
  59                            ad714x_spi_read, ad714x_spi_write);
  60        if (IS_ERR(chip))
  61                return PTR_ERR(chip);
  62
  63        spi_set_drvdata(spi, chip);
  64
  65        return 0;
  66}
  67
  68static int __devexit ad714x_spi_remove(struct spi_device *spi)
  69{
  70        struct ad714x_chip *chip = spi_get_drvdata(spi);
  71
  72        ad714x_remove(chip);
  73        spi_set_drvdata(spi, NULL);
  74
  75        return 0;
  76}
  77
  78static struct spi_driver ad714x_spi_driver = {
  79        .driver = {
  80                .name   = "ad714x_captouch",
  81                .owner  = THIS_MODULE,
  82                .pm     = &ad714x_spi_pm,
  83        },
  84        .probe          = ad714x_spi_probe,
  85        .remove         = __devexit_p(ad714x_spi_remove),
  86};
  87
  88static __init int ad714x_spi_init(void)
  89{
  90        return spi_register_driver(&ad714x_spi_driver);
  91}
  92module_init(ad714x_spi_init);
  93
  94static __exit void ad714x_spi_exit(void)
  95{
  96        spi_unregister_driver(&ad714x_spi_driver);
  97}
  98module_exit(ad714x_spi_exit);
  99
 100MODULE_DESCRIPTION("Analog Devices AD714X Capacitance Touch Sensor SPI Bus Driver");
 101MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
 102MODULE_LICENSE("GPL");
 103