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

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/*
* AD714X CapTouch Programmable Controller driver (SPI bus)
*
* Copyright 2009 Analog Devices Inc.
*
* Licensed under the GPL-2 or later.
*/
#include <linux/input.h> /* BUS_SPI */
#include <linux/module.h>
#include <linux/spi/spi.h>
#include <linux/pm.h>
#include <linux/types.h>
#include "ad714x.h"
#define AD714x_SPI_CMD_PREFIX 0xE000 /* bits 15:11 */
#define AD714x_SPI_READ BIT(10)
#ifdef CONFIG_PM
static int ad714x_spi_suspend(struct device *dev)
{
return ad714x_disable(spi_get_drvdata(to_spi_device(dev)));
}
static int ad714x_spi_resume(struct device *dev)
{
return ad714x_enable(spi_get_drvdata(to_spi_device(dev)));
}
#endif
static SIMPLE_DEV_PM_OPS(ad714x_spi_pm, ad714x_spi_suspend, ad714x_spi_resume);
static int ad714x_spi_read(struct device *dev,
unsigned short reg, unsigned short *data)
{
struct spi_device *spi = to_spi_device(dev);
unsigned short tx = cpu_to_be16(AD714x_SPI_CMD_PREFIX |
AD714x_SPI_READ | reg);
int ret;
ret = spi_write_then_read(spi, &tx, 2, data, 2);
*data = be16_to_cpup(data);
return ret;
}
static int ad714x_spi_write(struct device *dev,
unsigned short reg, unsigned short data)
{
struct spi_device *spi = to_spi_device(dev);
unsigned short tx[2] = {
cpu_to_be16(AD714x_SPI_CMD_PREFIX | reg),
cpu_to_be16(data)
};
return spi_write(spi, (u8 *)tx, 4);
}
static int __devinit ad714x_spi_probe(struct spi_device *spi)
{
struct ad714x_chip *chip;
int err;
spi->bits_per_word = 8;
err = spi_setup(spi);
if (err < 0)
return err;
chip = ad714x_probe(&spi->dev, BUS_SPI, spi->irq,
ad714x_spi_read, ad714x_spi_write);
if (IS_ERR(chip))
return PTR_ERR(chip);
spi_set_drvdata(spi, chip);
return 0;
}
static int __devexit ad714x_spi_remove(struct spi_device *spi)
{
struct ad714x_chip *chip = spi_get_drvdata(spi);
ad714x_remove(chip);
spi_set_drvdata(spi, NULL);
return 0;
}
static struct spi_driver ad714x_spi_driver = {
.driver = {
.name = "ad714x_captouch",
.owner = THIS_MODULE,
.pm = &ad714x_spi_pm,
},
.probe = ad714x_spi_probe,
.remove = __devexit_p(ad714x_spi_remove),
};
static __init int ad714x_spi_init(void)
{
return spi_register_driver(&ad714x_spi_driver);
}
module_init(ad714x_spi_init);
static __exit void ad714x_spi_exit(void)
{
spi_unregister_driver(&ad714x_spi_driver);
}
module_exit(ad714x_spi_exit);
MODULE_DESCRIPTION("Analog Devices AD714X Capacitance Touch Sensor SPI Bus Driver");
MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
MODULE_LICENSE("GPL");