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/iio/iio.h>
  13#include <linux/property.h>
  14#include <linux/regmap.h>
  15#include <linux/spi/spi.h>
  16
  17#include <linux/iio/common/st_sensors_spi.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 st_sensors_platform_data *pdata;
  41        struct device *dev = &spi->dev;
  42
  43        if (device_property_read_bool(dev, "spi-3wire"))
  44                return true;
  45
  46        pdata = dev_get_platdata(dev);
  47        if (pdata && pdata->spi_3wire)
  48                return true;
  49
  50        return false;
  51}
  52
  53/*
  54 * st_sensors_configure_spi_3_wire() - configure SPI 3-wire if needed
  55 * @spi: spi device reference.
  56 * @settings: sensor specific settings reference.
  57 *
  58 * Return: 0 on success, else a negative error code.
  59 */
  60static int st_sensors_configure_spi_3_wire(struct spi_device *spi,
  61                                           struct st_sensor_settings *settings)
  62{
  63        if (settings->sim.addr) {
  64                u8 buffer[] = {
  65                        settings->sim.addr,
  66                        settings->sim.value
  67                };
  68
  69                return spi_write(spi, buffer, 2);
  70        }
  71
  72        return 0;
  73}
  74
  75/*
  76 * st_sensors_spi_configure() - configure SPI interface
  77 * @indio_dev: IIO device reference.
  78 * @spi: spi device reference.
  79 *
  80 * Return: 0 on success, else a negative error code.
  81 */
  82int st_sensors_spi_configure(struct iio_dev *indio_dev,
  83                             struct spi_device *spi)
  84{
  85        struct st_sensor_data *sdata = iio_priv(indio_dev);
  86        const struct regmap_config *config;
  87        int err;
  88
  89        if (st_sensors_is_spi_3_wire(spi)) {
  90                err = st_sensors_configure_spi_3_wire(spi,
  91                                                      sdata->sensor_settings);
  92                if (err < 0)
  93                        return err;
  94        }
  95
  96        if (sdata->sensor_settings->multi_read_bit)
  97                config = &st_sensors_spi_regmap_multiread_bit_config;
  98        else
  99                config = &st_sensors_spi_regmap_config;
 100
 101        sdata->regmap = devm_regmap_init_spi(spi, config);
 102        if (IS_ERR(sdata->regmap)) {
 103                dev_err(&spi->dev, "Failed to register spi regmap (%ld)\n",
 104                        PTR_ERR(sdata->regmap));
 105                return PTR_ERR(sdata->regmap);
 106        }
 107
 108        spi_set_drvdata(spi, indio_dev);
 109
 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