121 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * STMicroelectronics sensors spi library driver4 *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 0xc020 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 selected34 * @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 needed55 * @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.value67 };68 69 return spi_write(spi, buffer, 2);70 }71 72 return 0;73}74 75/*76 * st_sensors_spi_configure() - configure SPI interface77 * @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 else99 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->irq = spi->irq;113 114 return 0;115}116EXPORT_SYMBOL_NS(st_sensors_spi_configure, IIO_ST_SENSORS);117 118MODULE_AUTHOR("Denis Ciocca <denis.ciocca@st.com>");119MODULE_DESCRIPTION("STMicroelectronics ST-sensors spi driver");120MODULE_LICENSE("GPL v2");121