linux/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_spi.c
Lorenzo Bianconi d3f770582a iio: imu: st_lsm6dsx: add system power management support
Add system sleep power management support to st_lsm6dsx driver.
In particular during suspend phase each sensor is disabled and
hw fifo is configured in bypass in order to avoid subsequent
I/O operations. The patch has been tested on HiKey board device

Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@st.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2017-04-30 17:55:15 +01:00

130 lines
2.8 KiB
C

/*
* STMicroelectronics st_lsm6dsx spi driver
*
* Copyright 2016 STMicroelectronics Inc.
*
* Lorenzo Bianconi <lorenzo.bianconi@st.com>
* Denis Ciocca <denis.ciocca@st.com>
*
* Licensed under the GPL-2.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/spi/spi.h>
#include <linux/slab.h>
#include <linux/of.h>
#include "st_lsm6dsx.h"
#define SENSORS_SPI_READ BIT(7)
static int st_lsm6dsx_spi_read(struct device *dev, u8 addr, int len,
u8 *data)
{
struct spi_device *spi = to_spi_device(dev);
struct st_lsm6dsx_hw *hw = spi_get_drvdata(spi);
int err;
struct spi_transfer xfers[] = {
{
.tx_buf = hw->tb.tx_buf,
.bits_per_word = 8,
.len = 1,
},
{
.rx_buf = hw->tb.rx_buf,
.bits_per_word = 8,
.len = len,
}
};
hw->tb.tx_buf[0] = addr | SENSORS_SPI_READ;
err = spi_sync_transfer(spi, xfers, ARRAY_SIZE(xfers));
if (err < 0)
return err;
memcpy(data, hw->tb.rx_buf, len * sizeof(u8));
return len;
}
static int st_lsm6dsx_spi_write(struct device *dev, u8 addr, int len,
u8 *data)
{
struct st_lsm6dsx_hw *hw;
struct spi_device *spi;
if (len >= ST_LSM6DSX_TX_MAX_LENGTH)
return -ENOMEM;
spi = to_spi_device(dev);
hw = spi_get_drvdata(spi);
hw->tb.tx_buf[0] = addr;
memcpy(&hw->tb.tx_buf[1], data, len);
return spi_write(spi, hw->tb.tx_buf, len + 1);
}
static const struct st_lsm6dsx_transfer_function st_lsm6dsx_transfer_fn = {
.read = st_lsm6dsx_spi_read,
.write = st_lsm6dsx_spi_write,
};
static int st_lsm6dsx_spi_probe(struct spi_device *spi)
{
const struct spi_device_id *id = spi_get_device_id(spi);
return st_lsm6dsx_probe(&spi->dev, spi->irq,
(int)id->driver_data, id->name,
&st_lsm6dsx_transfer_fn);
}
static const struct of_device_id st_lsm6dsx_spi_of_match[] = {
{
.compatible = "st,lsm6ds3",
.data = (void *)ST_LSM6DS3_ID,
},
{
.compatible = "st,lsm6ds3h",
.data = (void *)ST_LSM6DS3H_ID,
},
{
.compatible = "st,lsm6dsl",
.data = (void *)ST_LSM6DSL_ID,
},
{
.compatible = "st,lsm6dsm",
.data = (void *)ST_LSM6DSM_ID,
},
{},
};
MODULE_DEVICE_TABLE(of, st_lsm6dsx_spi_of_match);
static const struct spi_device_id st_lsm6dsx_spi_id_table[] = {
{ ST_LSM6DS3_DEV_NAME, ST_LSM6DS3_ID },
{ ST_LSM6DS3H_DEV_NAME, ST_LSM6DS3H_ID },
{ ST_LSM6DSL_DEV_NAME, ST_LSM6DSL_ID },
{ ST_LSM6DSM_DEV_NAME, ST_LSM6DSM_ID },
{},
};
MODULE_DEVICE_TABLE(spi, st_lsm6dsx_spi_id_table);
static struct spi_driver st_lsm6dsx_driver = {
.driver = {
.name = "st_lsm6dsx_spi",
.pm = &st_lsm6dsx_pm_ops,
.of_match_table = of_match_ptr(st_lsm6dsx_spi_of_match),
},
.probe = st_lsm6dsx_spi_probe,
.id_table = st_lsm6dsx_spi_id_table,
};
module_spi_driver(st_lsm6dsx_driver);
MODULE_AUTHOR("Lorenzo Bianconi <lorenzo.bianconi@st.com>");
MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
MODULE_DESCRIPTION("STMicroelectronics st_lsm6dsx spi driver");
MODULE_LICENSE("GPL v2");