linux-sg2042/drivers/input/misc/ad714x-spi.c

104 lines
2.3 KiB
C

/*
* AD714X CapTouch Programmable Controller driver (SPI bus)
*
* Copyright 2009 Analog Devices Inc.
*
* Licensed under the GPL-2 or later.
*/
#include <linux/input.h> /* BUS_I2C */
#include <linux/module.h>
#include <linux/spi/spi.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 spi_device *spi, pm_message_t message)
{
return ad714x_disable(spi_get_drvdata(spi));
}
static int ad714x_spi_resume(struct spi_device *spi)
{
return ad714x_enable(spi_get_drvdata(spi));
}
#else
# define ad714x_spi_suspend NULL
# define ad714x_spi_resume NULL
#endif
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 = AD714x_SPI_CMD_PREFIX | AD714x_SPI_READ | reg;
return spi_write_then_read(spi, (u8 *)&tx, 2, (u8 *)data, 2);
}
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] = {
AD714x_SPI_CMD_PREFIX | reg,
data
};
return spi_write(spi, (u8 *)tx, 4);
}
static int __devinit ad714x_spi_probe(struct spi_device *spi)
{
struct ad714x_chip *chip;
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,
},
.probe = ad714x_spi_probe,
.remove = __devexit_p(ad714x_spi_remove),
.suspend = ad714x_spi_suspend,
.resume = ad714x_spi_resume,
};
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");