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