mirror of
https://github.com/torvalds/linux.git
synced 2024-12-29 14:21:47 +00:00
9eff794b77
The interrupt status registers should be read in row to avoid invalid data. Alter "read" method for both bus options to allow reading several registers in a row and make sure we read interrupt status registers properly. Read sequence saves 50% of bus transactions compared to single register reads. So use it also for the result registers, which are also located in a row. Also update copyright notice. Signed-off-by: Michael Hennerich <michael.hennerich@analog.com> Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
141 lines
3.2 KiB
C
141 lines
3.2 KiB
C
/*
|
|
* 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)
|
|
|
|
#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 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 __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");
|