iio: accel: bma400: add support for bma400 spi (9bea1064) · Commits · 戴 / test

drivers/iio/accel/Kconfig

+7 −1

Original line number	Diff line number	Diff line
		@@ -116,18 +116,24 @@ config BMA400
		tristate "Bosch BMA400 3-Axis Accelerometer Driver"
		select REGMAP
		select BMA400_I2C if I2C
		select BMA400_SPI if SPI
		help
		Say Y here if you want to build a driver for the Bosch BMA400
		triaxial acceleration sensor.

		To compile this driver as a module, choose M here: the
		module will be called bma400_core and you will also get
		bma400_i2c if I2C is enabled.
		bma400_i2c if I2C is enabled and bma400_spi if SPI is
		enabled.

		config BMA400_I2C
		tristate
		depends on BMA400

		config BMA400_SPI
		tristate
		depends on BMA400

		config BMC150_ACCEL
		tristate "Bosch BMC150 Accelerometer Driver"
		select IIO_BUFFER

drivers/iio/accel/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -16,6 +16,7 @@ obj-$(CONFIG_BMA180) += bma180.o
		obj-$(CONFIG_BMA220) += bma220_spi.o
		obj-$(CONFIG_BMA400) += bma400_core.o
		obj-$(CONFIG_BMA400_I2C) += bma400_i2c.o
		obj-$(CONFIG_BMA400_SPI) += bma400_spi.o
		obj-$(CONFIG_BMC150_ACCEL) += bmc150-accel-core.o
		obj-$(CONFIG_BMC150_ACCEL_I2C) += bmc150-accel-i2c.o
		obj-$(CONFIG_BMC150_ACCEL_SPI) += bmc150-accel-spi.o

drivers/iio/accel/bma400_spi.c

0 → 100644

+120 −0

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0-only
		/*
		* SPI IIO driver for Bosch BMA400 triaxial acceleration sensor.
		*
		* Copyright 2020 Dan Robertson <dan@dlrobertson.com>
		*
		*/
		#include <linux/bits.h>
		#include <linux/init.h>
		#include <linux/mod_devicetable.h>
		#include <linux/module.h>
		#include <linux/regmap.h>
		#include <linux/spi/spi.h>

		#include "bma400.h"

		#define BMA400_MAX_SPI_READ 2
		#define BMA400_SPI_READ_BUFFER_SIZE (BMA400_MAX_SPI_READ + 1)

		static int bma400_regmap_spi_read(void *context,
		const void *reg, size_t reg_size,
		void *val, size_t val_size)
		{
		struct device *dev = context;
		struct spi_device *spi = to_spi_device(dev);
		u8 result[BMA400_SPI_READ_BUFFER_SIZE];
		ssize_t status;

		if (val_size > BMA400_MAX_SPI_READ)
		return -EINVAL;

		status = spi_write_then_read(spi, reg, 1, result, val_size + 1);
		if (status)
		return status;

		/*
		* From the BMA400 datasheet:
		*
		* > For a basic read operation two bytes have to be read and the first
		* > has to be dropped and the second byte must be interpreted.
		*/
		memcpy(val, result + 1, val_size);

		return 0;
		}

		static int bma400_regmap_spi_write(void context, const void data,
		size_t count)
		{
		struct device *dev = context;
		struct spi_device *spi = to_spi_device(dev);

		return spi_write(spi, data, count);
		}

		static struct regmap_bus bma400_regmap_bus = {
		.read = bma400_regmap_spi_read,
		.write = bma400_regmap_spi_write,
		.read_flag_mask = BIT(7),
		.max_raw_read = BMA400_MAX_SPI_READ,
		};

		static int bma400_spi_probe(struct spi_device *spi)
		{
		const struct spi_device_id *id = spi_get_device_id(spi);
		struct regmap *regmap;
		unsigned int val;
		int ret;

		regmap = devm_regmap_init(&spi->dev, &bma400_regmap_bus,
		&spi->dev, &bma400_regmap_config);
		if (IS_ERR(regmap)) {
		dev_err(&spi->dev, "failed to create regmap\n");
		return PTR_ERR(regmap);
		}

		/*
		* Per the bma400 datasheet, the first SPI read may
		* return garbage. As the datasheet recommends, the
		* chip ID register will be read here and checked
		* again in the following probe.
		*/
		ret = regmap_read(regmap, BMA400_CHIP_ID_REG, &val);
		if (ret)
		dev_err(&spi->dev, "Failed to read chip id register\n");

		return bma400_probe(&spi->dev, regmap, id->name);
		}

		static int bma400_spi_remove(struct spi_device *spi)
		{
		return bma400_remove(&spi->dev);
		}

		static const struct spi_device_id bma400_spi_ids[] = {
		{ "bma400", 0 },
		{ }
		};
		MODULE_DEVICE_TABLE(spi, bma400_spi_ids);

		static const struct of_device_id bma400_of_spi_match[] = {
		{ .compatible = "bosch,bma400" },
		{ }
		};
		MODULE_DEVICE_TABLE(of, bma400_of_spi_match);

		static struct spi_driver bma400_spi_driver = {
		.driver = {
		.name = "bma400",
		.of_match_table = bma400_of_spi_match,
		},
		.probe = bma400_spi_probe,
		.remove = bma400_spi_remove,
		.id_table = bma400_spi_ids,
		};

		module_spi_driver(bma400_spi_driver);
		MODULE_AUTHOR("Dan Robertson <dan@dlrobertson.com>");
		MODULE_DESCRIPTION("Bosch BMA400 triaxial acceleration sensor (SPI)");
		MODULE_LICENSE("GPL");

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