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/*
* AD714X CapTouch Programmable Controller driver (SPI bus)
*
* Copyright 2009-2011 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)
static int __maybe_unused ad714x_spi_suspend(struct device *dev)
{
return ad714x_disable(spi_get_drvdata(to_spi_device(dev)));
}
static int __maybe_unused ad714x_spi_resume(struct device *dev)
{
return ad714x_enable(spi_get_drvdata(to_spi_device(dev)));
}
static SIMPLE_DEV_PM_OPS(ad714x_spi_pm, ad714x_spi_suspend, ad714x_spi_resume);
static int ad714x_spi_read(struct ad714x_chip *chip,
unsigned short reg, unsigned short *data, size_t len)
{
struct spi_device *spi = to_spi_device(chip->dev);
struct spi_message message;
struct spi_transfer xfer[2];
int i;
int error;
spi_message_init(&message);
memset(xfer, 0, sizeof(xfer));
chip->xfer_buf[0] = cpu_to_be16(AD714x_SPI_CMD_PREFIX |
AD714x_SPI_READ | reg);
xfer[0].tx_buf = &chip->xfer_buf[0];
xfer[0].len = sizeof(chip->xfer_buf[0]);
spi_message_add_tail(&xfer[0], &message);
xfer[1].rx_buf = &chip->xfer_buf[1];
xfer[1].len = sizeof(chip->xfer_buf[1]) * len;
spi_message_add_tail(&xfer[1], &message);
error = spi_sync(spi, &message);
if (unlikely(error)) {
dev_err(chip->dev, "SPI read error: %d\n", error);
return error;
}
for (i = 0; i < len; i++)
data[i] = be16_to_cpu(chip->xfer_buf[i + 1]);
return 0;
}
static int ad714x_spi_write(struct ad714x_chip *chip,
unsigned short reg, unsigned short data)
{
struct spi_device *spi = to_spi_device(chip->dev);
int error;
chip->xfer_buf[0] = cpu_to_be16(AD714x_SPI_CMD_PREFIX | reg);
chip->xfer_buf[1] = cpu_to_be16(data);
error = spi_write(spi, (u8 *)chip->xfer_buf,
2 * sizeof(*chip->xfer_buf));
if (unlikely(error)) {
dev_err(chip->dev, "SPI write error: %d\n", error);
return error;
}
return 0;
}
static int 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 struct spi_driver ad714x_spi_driver = {
.driver = {
.name = "ad714x_captouch",
.pm = &ad714x_spi_pm,
},
.probe = ad714x_spi_probe,
};
module_spi_driver(ad714x_spi_driver);
MODULE_DESCRIPTION("Analog Devices AD714X Capacitance Touch Sensor SPI Bus Driver");
MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
MODULE_LICENSE("GPL");
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