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// SPDX-License-Identifier: GPL-2.0-only
/*
* STMicroelectronics sensors spi library driver
*
* Copyright 2012-2013 STMicroelectronics Inc.
*
* Denis Ciocca <denis.ciocca@st.com>
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/iio/iio.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/spi/spi.h>
#include <linux/iio/common/st_sensors_spi.h>
#define ST_SENSORS_SPI_MULTIREAD 0xc0
static const struct regmap_config st_sensors_spi_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
};
static const struct regmap_config st_sensors_spi_regmap_multiread_bit_config = {
.reg_bits = 8,
.val_bits = 8,
.read_flag_mask = ST_SENSORS_SPI_MULTIREAD,
};
/*
* st_sensors_is_spi_3_wire() - check if SPI 3-wire mode has been selected
* @spi: spi device reference.
*
* Return: true if SPI 3-wire mode is selected, false otherwise.
*/
static bool st_sensors_is_spi_3_wire(struct spi_device *spi)
{
struct st_sensors_platform_data *pdata;
struct device *dev = &spi->dev;
if (device_property_read_bool(dev, "spi-3wire"))
return true;
pdata = dev_get_platdata(dev);
if (pdata && pdata->spi_3wire)
return true;
return false;
}
/*
* st_sensors_configure_spi_3_wire() - configure SPI 3-wire if needed
* @spi: spi device reference.
* @settings: sensor specific settings reference.
*
* Return: 0 on success, else a negative error code.
*/
static int st_sensors_configure_spi_3_wire(struct spi_device *spi,
struct st_sensor_settings *settings)
{
if (settings->sim.addr) {
u8 buffer[] = {
settings->sim.addr,
settings->sim.value
};
return spi_write(spi, buffer, 2);
}
return 0;
}
/*
* st_sensors_spi_configure() - configure SPI interface
* @indio_dev: IIO device reference.
* @spi: spi device reference.
*
* Return: 0 on success, else a negative error code.
*/
int st_sensors_spi_configure(struct iio_dev *indio_dev,
struct spi_device *spi)
{
struct st_sensor_data *sdata = iio_priv(indio_dev);
const struct regmap_config *config;
int err;
if (st_sensors_is_spi_3_wire(spi)) {
err = st_sensors_configure_spi_3_wire(spi,
sdata->sensor_settings);
if (err < 0)
return err;
}
if (sdata->sensor_settings->multi_read_bit)
config = &st_sensors_spi_regmap_multiread_bit_config;
else
config = &st_sensors_spi_regmap_config;
sdata->regmap = devm_regmap_init_spi(spi, config);
if (IS_ERR(sdata->regmap)) {
dev_err(&spi->dev, "Failed to register spi regmap (%ld)\n",
PTR_ERR(sdata->regmap));
return PTR_ERR(sdata->regmap);
}
spi_set_drvdata(spi, indio_dev);
indio_dev->name = spi->modalias;
sdata->irq = spi->irq;
return 0;
}
EXPORT_SYMBOL_NS(st_sensors_spi_configure, IIO_ST_SENSORS);
MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
MODULE_DESCRIPTION("STMicroelectronics ST-sensors spi driver");
MODULE_LICENSE("GPL v2");
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