On 10/11/19 8:54 PM, Dan Robertson wrote:
> Add a IIO driver for the Bosch BMA400 3-axes ultra-low power accelerometer.
> The driver supports reading from the acceleration and temperature
> registers. The driver also supports reading and configuring the output data
> rate, oversampling ratio, and scale.
>
> Signed-off-by: Dan Robertson <[email protected]>
> ---
> drivers/iio/accel/Kconfig | 19 +
> drivers/iio/accel/Makefile | 2 +
> drivers/iio/accel/bma400.h | 86 ++++
> drivers/iio/accel/bma400_core.c | 839 ++++++++++++++++++++++++++++++++
> drivers/iio/accel/bma400_i2c.c | 58 +++
> 5 files changed, 1004 insertions(+)
> create mode 100644 drivers/iio/accel/bma400.h
> create mode 100644 drivers/iio/accel/bma400_core.c
> create mode 100644 drivers/iio/accel/bma400_i2c.c
>
> diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
> index 9b9656ce37e6..cca6727e037e 100644
> --- a/drivers/iio/accel/Kconfig
> +++ b/drivers/iio/accel/Kconfig
> @@ -112,6 +112,25 @@ config BMA220
> To compile this driver as a module, choose M here: the
> module will be called bma220_spi.
>
> +config BMA400
> + tristate "Bosch BMA400 3-Axis Accelerometer Driver"
> + depends on I2C
> + select REGMAP
> + select BMA400_I2C if (I2C)
Since this already has "depends on I2C", the "if (I2C)" above is not needed.
Or maybe BMA400 alone does not depend on I2C?
> + 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 for I2C
Add ending '.'.
> +
> +config BMA400_I2C
> + tristate
> + depends on BMA400
> + depends on I2C
> + select REGMAP_I2C
> +
The bma400_i2c driver seems to use some OF interfaces.
Should it also depend on OF?
> config BMC150_ACCEL
> tristate "Bosch BMC150 Accelerometer Driver"
> select IIO_BUFFER
> diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
> index 56bd0215e0d4..3a051cf37f40 100644
> --- a/drivers/iio/accel/Makefile
> +++ b/drivers/iio/accel/Makefile
> @@ -14,6 +14,8 @@ obj-$(CONFIG_ADXL372_I2C) += adxl372_i2c.o
> obj-$(CONFIG_ADXL372_SPI) += adxl372_spi.o
> 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-$(CONFIG_BMC150_ACCEL) += bmc150-accel-core.o
> obj-$(CONFIG_BMC150_ACCEL_I2C) += bmc150-accel-i2c.o
> obj-$(CONFIG_BMC150_ACCEL_SPI) += bmc150-accel-spi.o
> diff --git a/drivers/iio/accel/bma400_core.c b/drivers/iio/accel/bma400_core.c
> new file mode 100644
> index 000000000000..5b3cb8919c47
> --- /dev/null
> +++ b/drivers/iio/accel/bma400_core.c
> @@ -0,0 +1,839 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * bma400_core.c - Core IIO driver for Bosch BMA400 triaxial acceleration
> + * sensor. Used by bma400-i2c.
> + *
> + * Copyright 2019 Dan Robertson <[email protected]>
> + *
> + * TODO:
> + * - Support for power management
> + * - Support events and interrupts
> + * - Create channel the step count
> + * - Create channel for sensor time
> + */
> +
> +#include <linux/device.h>
> +#include <linux/module.h>
> +#include <linux/regmap.h>
> +#include <linux/bitops.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +
> +#include "bma400.h"
> +
[snip]
> +
> +struct bma400_data {
> + struct device *dev;
> + struct mutex mutex; /* data register lock */
#include <linux/mutex.h>
> + struct iio_mount_matrix orientation;
> + struct regmap *regmap;
> + enum bma400_power_mode power_mode;
> + const int *sample_freq;
> + int oversampling_ratio;
> + int scale;
> +};
[snip]
> +
> +static int bma400_get_accel_oversampling_ratio(struct bma400_data *data)
> +{
> + unsigned int val;
> + unsigned int osr;
> + int ret;
> +
> + /*
> + * The oversampling ratio is stored in a different register
> + * based on the power-mode. In normal mode the OSR is stored
> + * in ACC_CONFIG1. In low-power mode it is stored in
> + * ACC_CONFIG0.
> + */
> + switch (data->power_mode) {
> + case POWER_MODE_LOW:
> + ret = regmap_read(data->regmap, BMA400_ACC_CONFIG0_REG, &val);
> + if (ret < 0) {
> + data->oversampling_ratio = -1;
> + return ret;
> + }
> +
> + osr = (val & BMA400_LP_OSR_MASK) >> BMA400_LP_OSR_SHIFT;
> +
> + data->oversampling_ratio = osr;
> + return 0;
> + case POWER_MODE_NORMAL:
> + ret = regmap_read(data->regmap, BMA400_ACC_CONFIG1_REG, &val);
> + if (ret < 0) {
> + data->oversampling_ratio = -1;
> + return ret;
> + }
> +
> + osr = (val & BMA400_NP_OSR_MASK) >> BMA400_NP_OSR_SHIFT;
> +
> + data->oversampling_ratio = osr;
> + return 0;
> + default:
> + data->oversampling_ratio = -1;
> + return 0;
> + }
> +}
> +
> +static int bma400_set_accel_oversampling_ratio(struct bma400_data *data,
> + int val)
> +{
> + int ret;
> + unsigned int acc_config;
> +
> + if (val & ~BMA400_TWO_BITS_MASK)
> + return -EINVAL;
> +
> + /*
> + * The oversampling ratio is stored in a different register
> + * based on the power-mode.
> + */
> + switch (data->power_mode) {
> + case POWER_MODE_LOW:
> + ret = regmap_read(data->regmap, BMA400_ACC_CONFIG0_REG,
> + &acc_config);
> + if (acc_config < 0)
> + return acc_config;
> +
> + ret = regmap_write(data->regmap, BMA400_ACC_CONFIG0_REG,
> + (acc_config & ~BMA400_LP_OSR_MASK) |
> + (val << BMA400_LP_OSR_SHIFT));
> + if (ret < 0) {
> + dev_err(data->dev, "Failed to write out OSR");
> + return ret;
> + }
> +
> + data->oversampling_ratio = val;
> + return 0;
> + case POWER_MODE_NORMAL:
> + ret = regmap_read(data->regmap, BMA400_ACC_CONFIG1_REG,
> + &acc_config);
> + if (ret < 0)
> + return ret;
> +
> + ret = regmap_write(data->regmap, BMA400_ACC_CONFIG1_REG,
> + (acc_config & ~BMA400_NP_OSR_MASK) |
> + (val << BMA400_NP_OSR_SHIFT));
> + if (ret < 0) {
> + dev_err(data->dev, "Failed to write out OSR");
> + return ret;
> + }
> +
> + data->oversampling_ratio = val;
> + return 0;
> + default:
> + return -EINVAL;
> + }
> + return ret;
> +}
> +
> +static int bma400_get_accel_scale(struct bma400_data *data)
> +{
> + int idx;
> + int ret;
> + unsigned int val;
> +
> + ret = regmap_read(data->regmap, BMA400_ACC_CONFIG1_REG, &val);
> + if (ret < 0)
> + return ret;
> +
> + idx = (((val & BMA400_ACC_SCALE_MASK) >> BMA400_SCALE_SHIFT) * 2) + 1;
> + if (idx >= ARRAY_SIZE(bma400_scale_table))
> + return -EINVAL;
> +
> + data->scale = bma400_scale_table[idx];
> +
> + return 0;
> +}
> +
> +static int bma400_get_accel_scale_idx(struct bma400_data *data, int val)
> +{
> + int i;
> +
> + for (i = 1; i < ARRAY_SIZE(bma400_scale_table); i += 2) {
#include <linux/kernel.h>
> + if (bma400_scale_table[i] == val)
> + return i - 1;
> + }
> + return -EINVAL;
> +}
[snip]
--
~Randy
