diff options
| -rw-r--r-- | drivers/iio/accel/Kconfig | 8 | ||||
| -rw-r--r-- | drivers/iio/accel/Makefile | 1 | ||||
| -rw-r--r-- | drivers/iio/accel/bma400_spi.c | 120 |
3 files changed, 128 insertions, 1 deletions
diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig index 1080637ca40e..2e0c62c39155 100644 --- a/drivers/iio/accel/Kconfig +++ b/drivers/iio/accel/Kconfig @@ -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 diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile index 3a051cf37f40..4f6c1ebe13b0 100644 --- a/drivers/iio/accel/Makefile +++ b/drivers/iio/accel/Makefile @@ -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 diff --git a/drivers/iio/accel/bma400_spi.c b/drivers/iio/accel/bma400_spi.c new file mode 100644 index 000000000000..7c2825904e08 --- /dev/null +++ b/drivers/iio/accel/bma400_spi.c @@ -0,0 +1,120 @@ +// 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"); |