LXR linux/drivers/iio/common/st_sensors/st_sensors

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * STMicroelectronics sensors spi library driver
   4 *
   5 * Copyright 2012-2013 STMicroelectronics Inc.
   6 *
   7 * Denis Ciocca <denis.ciocca@st.com>
   8 */
   9
  10#include <linux/kernel.h>
  11#include <linux/module.h>
  12#include <linux/slab.h>
  13#include <linux/iio/iio.h>
  14#include <linux/regmap.h>
  15
  16#include <linux/iio/common/st_sensors_spi.h>
  17#include "st_sensors_core.h"
  18
  19#define ST_SENSORS_SPI_MULTIREAD        0xc0
  20
  21static const struct regmap_config st_sensors_spi_regmap_config = {
  22        .reg_bits = 8,
  23        .val_bits = 8,
  24};
  25
  26static const struct regmap_config st_sensors_spi_regmap_multiread_bit_config = {
  27        .reg_bits = 8,
  28        .val_bits = 8,
  29        .read_flag_mask = ST_SENSORS_SPI_MULTIREAD,
  30};
  31
  32/*
  33 * st_sensors_is_spi_3_wire() - check if SPI 3-wire mode has been selected
  34 * @spi: spi device reference.
  35 *
  36 * Return: true if SPI 3-wire mode is selected, false otherwise.
  37 */
  38static bool st_sensors_is_spi_3_wire(struct spi_device *spi)
  39{
  40        struct device_node *np = spi->dev.of_node;
  41        struct st_sensors_platform_data *pdata;
  42
  43        pdata = (struct st_sensors_platform_data *)spi->dev.platform_data;
  44        if ((np && of_property_read_bool(np, "spi-3wire")) ||
  45            (pdata && pdata->spi_3wire)) {
  46                return true;
  47        }
  48
  49        return false;
  50}
  51
  52/*
  53 * st_sensors_configure_spi_3_wire() - configure SPI 3-wire if needed
  54 * @spi: spi device reference.
  55 * @settings: sensor specific settings reference.
  56 *
  57 * Return: 0 on success, else a negative error code.
  58 */
  59static int st_sensors_configure_spi_3_wire(struct spi_device *spi,
  60                                           struct st_sensor_settings *settings)
  61{
  62        if (settings->sim.addr) {
  63                u8 buffer[] = {
  64                        settings->sim.addr,
  65                        settings->sim.value
  66                };
  67
  68                return spi_write(spi, buffer, 2);
  69        }
  70
  71        return 0;
  72}
  73
  74/*
  75 * st_sensors_spi_configure() - configure SPI interface
  76 * @indio_dev: IIO device reference.
  77 * @spi: spi device reference.
  78 *
  79 * Return: 0 on success, else a negative error code.
  80 */
  81int st_sensors_spi_configure(struct iio_dev *indio_dev,
  82                             struct spi_device *spi)
  83{
  84        struct st_sensor_data *sdata = iio_priv(indio_dev);
  85        const struct regmap_config *config;
  86        int err;
  87
  88        if (st_sensors_is_spi_3_wire(spi)) {
  89                err = st_sensors_configure_spi_3_wire(spi,
  90                                                      sdata->sensor_settings);
  91                if (err < 0)
  92                        return err;
  93        }
  94
  95        if (sdata->sensor_settings->multi_read_bit)
  96                config = &st_sensors_spi_regmap_multiread_bit_config;
  97        else
  98                config = &st_sensors_spi_regmap_config;
  99
 100        sdata->regmap = devm_regmap_init_spi(spi, config);
 101        if (IS_ERR(sdata->regmap)) {
 102                dev_err(&spi->dev, "Failed to register spi regmap (%d)\n",
 103                        (int)PTR_ERR(sdata->regmap));
 104                return PTR_ERR(sdata->regmap);
 105        }
 106
 107        spi_set_drvdata(spi, indio_dev);
 108
 109        indio_dev->dev.parent = &spi->dev;
 110        indio_dev->name = spi->modalias;
 111
 112        sdata->dev = &spi->dev;
 113        sdata->irq = spi->irq;
 114
 115        return 0;
 116}
 117EXPORT_SYMBOL(st_sensors_spi_configure);
 118
 119MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");
 120MODULE_DESCRIPTION("STMicroelectronics ST-sensors spi driver");
 121MODULE_LICENSE("GPL v2");
 122