[PATCH v5 2/2] iio: accel: Add support for the Bosch-Sensortec BMI088

From: Mike Looijmans
Date: Tue Mar 24 2020 - 04:03:24 EST

The BMI088 is a combined module with both accelerometer and gyroscope.
This adds the accelerometer driver support for the SPI interface.
The gyroscope part is already supported by the BMG160 driver.

Signed-off-by: Mike Looijmans <mike.looijmans@xxxxxxxx>
---
v2: Remove unused typedefs and variables
Fix error return when iio_device_register fails
v3: Processed comments from Jonathan Cameron and Lars-Peter Clausen
implement runtime PM (tested by code tracing) and sleep
fix scale and offset factors for accel and temperature and
return raw values instead of pre-scaled ones
Use iio_device_{claim,release}_direct_mode
Remove unused code and structs
Use a cache-aligned buffer for bulk read
Configure and enable caching register values
v4: Remove unused #include directives
Remove unused #defines for event and irq
Replace (ret < 0) with (ret) for all regmap calls
Consistent checking of IO errors in probe and init
Removed #ifdef CONFIG_PM guard
Use bitops for set_frequency instead of loop with shift
s/__s16/s16/g
Remove excess blank lines
Don't return -EAGAIN in pm_runtime
v5: Add includes and forward defines in header
BIT(7) instead of 0x80
Reset already sets defaults, do not set them again
Remove now unused bmi088_accel_set_bw
Remove unused AXIS_MAX
Use MASK define for ODR setting
Explain buffer use and alignment
Split bmi088_accel_set_power_state into "on" and "off" parts
Cosmetic changes to improve readability

drivers/iio/accel/Kconfig | 17 +
drivers/iio/accel/Makefile | 2 +
drivers/iio/accel/bmi088-accel-core.c | 610 ++++++++++++++++++++++++++
drivers/iio/accel/bmi088-accel-spi.c | 85 ++++
drivers/iio/accel/bmi088-accel.h | 18 +
5 files changed, 732 insertions(+)
create mode 100644 drivers/iio/accel/bmi088-accel-core.c
create mode 100644 drivers/iio/accel/bmi088-accel-spi.c
create mode 100644 drivers/iio/accel/bmi088-accel.h

diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index 5d91a6dda894..7ed9c82b731b 100644
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -151,6 +151,23 @@ config BMC150_ACCEL_SPI
tristate
select REGMAP_SPI

+config BMI088_ACCEL
+ tristate "Bosch BMI088 Accelerometer Driver"
+ select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER
+ select REGMAP
+ select BMI088_ACCEL_SPI
+ help
+ Say yes here to build support for the Bosch BMI088 accelerometer.
+
+ This is a combo module with both accelerometer and gyroscope.
+ This driver is only implementing accelerometer part, which has
+ its own address and register map.
+
+config BMI088_ACCEL_SPI
+ tristate
+ select REGMAP_SPI
+
config DA280
tristate "MiraMEMS DA280 3-axis 14-bit digital accelerometer driver"
depends on I2C
diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
index 3a051cf37f40..f44613103ae5 100644
--- a/drivers/iio/accel/Makefile
+++ b/drivers/iio/accel/Makefile
@@ -19,6 +19,8 @@ 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
+obj-$(CONFIG_BMI088_ACCEL) += bmi088-accel-core.o
+obj-$(CONFIG_BMI088_ACCEL_SPI) += bmi088-accel-spi.o
obj-$(CONFIG_DA280) += da280.o
obj-$(CONFIG_DA311) += da311.o
obj-$(CONFIG_DMARD06) += dmard06.o
diff --git a/drivers/iio/accel/bmi088-accel-core.c b/drivers/iio/accel/bmi088-accel-core.c
new file mode 100644
index 000000000000..c1d9a8ba2f46
--- /dev/null
+++ b/drivers/iio/accel/bmi088-accel-core.c
@@ -0,0 +1,610 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 3-axis accelerometer driver supporting following Bosch-Sensortec chips:
+ * - BMI088
+ *
+ * Copyright (c) 2018-2020, Topic Embedded Products
+ */
+
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/acpi.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/regmap.h>
+#include <asm/unaligned.h>
+
+#include "bmi088-accel.h"
+
+#define BMI088_ACCEL_REG_CHIP_ID 0x00
+#define BMI088_ACCEL_REG_ERROR 0x02
+
+#define BMI088_ACCEL_REG_INT_STATUS 0x1D
+#define BMI088_ACCEL_INT_STATUS_BIT_DRDY BIT(7)
+
+#define BMI088_ACCEL_REG_RESET 0x7E
+#define BMI088_ACCEL_RESET_VAL 0xB6
+
+#define BMI088_ACCEL_REG_PWR_CTRL 0x7D
+#define BMI088_ACCEL_REG_PWR_CONF 0x7C
+
+#define BMI088_ACCEL_REG_INT_MAP_DATA 0x58
+#define BMI088_ACCEL_INT_MAP_DATA_BIT_INT1_DRDY BIT(2)
+#define BMI088_ACCEL_INT_MAP_DATA_BIT_INT2_FWM BIT(5)
+
+#define BMI088_ACCEL_REG_INT1_IO_CONF 0x53
+#define BMI088_ACCEL_INT1_IO_CONF_BIT_ENABLE_OUT BIT(3)
+#define BMI088_ACCEL_INT1_IO_CONF_BIT_LVL BIT(1)
+
+#define BMI088_ACCEL_REG_INT2_IO_CONF 0x54
+#define BMI088_ACCEL_INT2_IO_CONF_BIT_ENABLE_OUT BIT(3)
+#define BMI088_ACCEL_INT2_IO_CONF_BIT_LVL BIT(1)
+
+#define BMI088_ACCEL_REG_ACC_CONF 0x40
+#define BMI088_ACCEL_MODE_ODR_MASK 0x0f
+
+#define BMI088_ACCEL_REG_ACC_RANGE 0x41
+#define BMI088_ACCEL_RANGE_3G 0x00
+#define BMI088_ACCEL_RANGE_6G 0x01
+#define BMI088_ACCEL_RANGE_12G 0x02
+#define BMI088_ACCEL_RANGE_24G 0x03
+
+#define BMI088_ACCEL_REG_TEMP 0x22
+#define BMI088_ACCEL_REG_TEMP_SHIFT 5
+#define BMI088_ACCEL_TEMP_UNIT 125
+#define BMI088_ACCEL_TEMP_OFFSET 23000
+
+#define BMI088_ACCEL_REG_XOUT_L 0x12
+#define BMI088_ACCEL_AXIS_TO_REG(axis) \
+ (BMI088_ACCEL_REG_XOUT_L + (axis * 2))
+
+#define BMI088_ACCEL_MAX_STARTUP_TIME_US 1000
+#define BMI088_AUTO_SUSPEND_DELAY_MS 2000
+
+#define BMI088_ACCEL_REG_FIFO_STATUS 0x0E
+#define BMI088_ACCEL_REG_FIFO_CONFIG0 0x48
+#define BMI088_ACCEL_REG_FIFO_CONFIG1 0x49
+#define BMI088_ACCEL_REG_FIFO_DATA 0x3F
+#define BMI088_ACCEL_FIFO_LENGTH 100
+
+#define BMI088_ACCEL_FIFO_MODE_FIFO 0x40
+#define BMI088_ACCEL_FIFO_MODE_STREAM 0x80
+
+enum bmi088_accel_axis {
+ AXIS_X,
+ AXIS_Y,
+ AXIS_Z,
+};
+
+enum bmi088_power_modes {
+ BMI088_ACCEL_MODE_ACTIVE,
+ BMI088_ACCEL_MODE_SUSPEND,
+};
+
+/* Available OSR (over sampling rate) sets the 3dB cut-off frequency */
+enum bmi088_osr_modes {
+ BMI088_ACCEL_MODE_OSR_NORMAL = 0xA,
+ BMI088_ACCEL_MODE_OSR_2 = 0x9,
+ BMI088_ACCEL_MODE_OSR_4 = 0x8,
+};
+
+/* Available ODR (output data rates) in Hz */
+enum bmi088_odr_modes {
+ BMI088_ACCEL_MODE_ODR_12_5 = 0x5,
+ BMI088_ACCEL_MODE_ODR_25 = 0x6,
+ BMI088_ACCEL_MODE_ODR_50 = 0x7,
+ BMI088_ACCEL_MODE_ODR_100 = 0x8,
+ BMI088_ACCEL_MODE_ODR_200 = 0x9,
+ BMI088_ACCEL_MODE_ODR_400 = 0xa,
+ BMI088_ACCEL_MODE_ODR_800 = 0xb,
+ BMI088_ACCEL_MODE_ODR_1600 = 0xc,
+};
+
+struct bmi088_scale_info {
+ int scale;
+ u8 reg_range;
+};
+
+struct bmi088_accel_chip_info {
+ const char *name;
+ u8 chip_id;
+ const struct iio_chan_spec *channels;
+ int num_channels;
+};
+
+struct bmi088_accel_data {
+ struct regmap *regmap;
+ struct mutex mutex;
+ const struct bmi088_accel_chip_info *chip_info;
+ u8 buffer[2] ____cacheline_aligned; /* shared DMA safe buffer */
+};
+
+static const struct regmap_range bmi088_volatile_ranges[] = {
+ /* All registers below 0x40 are volatile, except the CHIP ID. */
+ regmap_reg_range(BMI088_ACCEL_REG_ERROR, 0x3f),
+ /* Mark the RESET as volatile too, it is self-clearing */
+ regmap_reg_range(BMI088_ACCEL_REG_RESET, BMI088_ACCEL_REG_RESET),
+};
+
+static const struct regmap_access_table bmi088_volatile_table = {
+ .yes_ranges = bmi088_volatile_ranges,
+ .n_yes_ranges = ARRAY_SIZE(bmi088_volatile_ranges),
+};
+
+const struct regmap_config bmi088_regmap_conf = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = 0x7E,
+ .volatile_table = &bmi088_volatile_table,
+ .cache_type = REGCACHE_RBTREE,
+};
+EXPORT_SYMBOL_GPL(bmi088_regmap_conf);
+
+static int bmi088_accel_set_power_state_on(struct bmi088_accel_data *data)
+{
+ struct device *dev = regmap_get_device(data->regmap);
+ int ret;
+
+ ret = pm_runtime_get_sync(dev);
+ if (ret < 0) {
+ pm_runtime_put_noidle(dev);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int bmi088_accel_set_power_state_off(struct bmi088_accel_data *data)
+{
+ struct device *dev = regmap_get_device(data->regmap);
+ int ret;
+
+ pm_runtime_mark_last_busy(dev);
+ ret = pm_runtime_put_autosuspend(dev);
+
+ return ret < 0 ? ret : 0;
+}
+
+/*
+ * The register ACC_PWR_CTRL enables and disables the accelerometer and the
+ * temperature sensor.
+ */
+static int bmi088_accel_enable(struct bmi088_accel_data *data, bool on_off)
+{
+ struct device *dev = regmap_get_device(data->regmap);
+ unsigned int val = on_off ? 0x4 : 0x0;
+ int ret;
+
+ ret = regmap_write(data->regmap, BMI088_ACCEL_REG_PWR_CTRL, val);
+ if (ret) {
+ dev_err(dev, "Error writing ACC_PWR_CTRL reg\n");
+ return ret;
+ }
+ /* Datasheet recommends to wait at least 5ms before communication */
+ usleep_range(5000, 6000);
+
+ return 0;
+}
+
+/* In suspend mode, only the accelerometer is powered down. */
+static int bmi088_accel_set_mode(struct bmi088_accel_data *data,
+ enum bmi088_power_modes mode)
+{
+ struct device *dev = regmap_get_device(data->regmap);
+ unsigned int val = mode == BMI088_ACCEL_MODE_SUSPEND ? 0x3 : 0x0;
+ int ret;
+
+ ret = regmap_write(data->regmap, BMI088_ACCEL_REG_PWR_CONF, val);
+ if (ret) {
+ dev_err(dev, "Error writing ACCEL_PWR_CONF reg\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static int bmi088_accel_get_sample_freq(struct bmi088_accel_data *data,
+ int *val, int *val2)
+{
+ unsigned int value;
+ int ret;
+
+ ret = regmap_read(data->regmap, BMI088_ACCEL_REG_ACC_CONF,
+ &value);
+ if (ret)
+ return ret;
+
+ value &= BMI088_ACCEL_MODE_ODR_MASK;
+ if (value == BMI088_ACCEL_MODE_ODR_12_5) {
+ *val = 12;
+ *val2 = 500000;
+ ret = IIO_VAL_INT_PLUS_MICRO;
+ } else {
+ *val = 25 << (value - BMI088_ACCEL_MODE_ODR_25);
+ *val2 = 0;
+ ret = IIO_VAL_INT;
+ }
+
+ return ret;
+}
+
+static int bmi088_accel_set_sample_freq(struct bmi088_accel_data *data, int val)
+{
+ unsigned int value;
+
+ if (val < 12 || val > 1600)
+ return -EINVAL;
+
+ value = fls(val) + 1;
+
+ return regmap_update_bits(data->regmap, BMI088_ACCEL_REG_ACC_CONF,
+ BMI088_ACCEL_MODE_ODR_MASK, value);
+}
+
+static int bmi088_accel_get_temp(struct bmi088_accel_data *data, int *val)
+{
+ int ret;
+ s16 temp;
+
+ mutex_lock(&data->mutex);
+
+ ret = regmap_bulk_read(data->regmap, BMI088_ACCEL_REG_TEMP,
+ &data->buffer, sizeof(__be16));
+ /* data->buffer is cacheline aligned */
+ temp = be16_to_cpu(*(__be16 *)data->buffer);
+
+ mutex_unlock(&data->mutex);
+
+ if (ret)
+ return ret;
+
+ *val = temp >> BMI088_ACCEL_REG_TEMP_SHIFT;
+
+ return IIO_VAL_INT;
+}
+
+static int bmi088_accel_get_axis(struct bmi088_accel_data *data,
+ struct iio_chan_spec const *chan,
+ int *val)
+{
+ int ret;
+ s16 raw_val;
+
+ mutex_lock(&data->mutex);
+
+ ret = bmi088_accel_set_power_state_on(data);
+ if (ret)
+ return ret;
+
+ ret = regmap_bulk_read(data->regmap,
+ BMI088_ACCEL_AXIS_TO_REG(chan->scan_index),
+ data->buffer, sizeof(__le16));
+ raw_val = le16_to_cpu(*(__le16 *)data->buffer);
+
+ bmi088_accel_set_power_state_off(data);
+
+ mutex_unlock(&data->mutex);
+
+ if (ret)
+ return ret;
+
+ *val = raw_val;
+
+ return IIO_VAL_INT;
+}
+
+static int bmi088_accel_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct bmi088_accel_data *data = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ switch (chan->type) {
+ case IIO_TEMP:
+ return bmi088_accel_get_temp(data, val);
+ case IIO_ACCEL:
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+
+ ret = bmi088_accel_get_axis(data, chan, val);
+ iio_device_release_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+ case IIO_CHAN_INFO_OFFSET:
+ switch (chan->type) {
+ case IIO_TEMP:
+ /* Offset applies before scale */
+ *val = BMI088_ACCEL_TEMP_OFFSET/BMI088_ACCEL_TEMP_UNIT;
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+ case IIO_CHAN_INFO_SCALE:
+ *val = 0;
+ switch (chan->type) {
+ case IIO_TEMP:
+ /* 0.125 degrees per LSB */
+ *val = BMI088_ACCEL_TEMP_UNIT;
+ return IIO_VAL_INT;
+ case IIO_ACCEL:
+ ret = regmap_read(data->regmap,
+ BMI088_ACCEL_REG_ACC_RANGE, val);
+ if (ret)
+ return ret;
+
+ *val2 = 15 - (*val & 0x3);
+ *val = 3 * 980;
+
+ return IIO_VAL_FRACTIONAL_LOG2;
+ default:
+ return -EINVAL;
+ }
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ mutex_lock(&data->mutex);
+ ret = bmi088_accel_get_sample_freq(data, val, val2);
+ mutex_unlock(&data->mutex);
+ return ret;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int bmi088_accel_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ struct bmi088_accel_data *data = iio_priv(indio_dev);
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ mutex_lock(&data->mutex);
+ ret = bmi088_accel_set_sample_freq(data, val);
+ mutex_unlock(&data->mutex);
+ return ret;
+ default:
+ return -EINVAL;
+ }
+}
+
+static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("12.5 25 50 100 200 400 800 1600");
+
+static struct attribute *bmi088_accel_attributes[] = {
+ &iio_const_attr_sampling_frequency_available.dev_attr.attr,
+ NULL
+};
+
+static const struct attribute_group bmi088_accel_attrs_group = {
+ .attrs = bmi088_accel_attributes,
+};
+
+#define BMI088_ACCEL_CHANNEL(_axis) { \
+ .type = IIO_ACCEL, \
+ .modified = 1, \
+ .channel2 = IIO_MOD_##_axis, \
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
+ BIT(IIO_CHAN_INFO_SAMP_FREQ), \
+ .scan_index = AXIS_##_axis, \
+}
+
+static const struct iio_chan_spec bmi088_accel_channels[] = {
+ {
+ .type = IIO_TEMP,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_OFFSET),
+ .scan_index = -1,
+ },
+ BMI088_ACCEL_CHANNEL(X),
+ BMI088_ACCEL_CHANNEL(Y),
+ BMI088_ACCEL_CHANNEL(Z),
+ IIO_CHAN_SOFT_TIMESTAMP(3),
+};
+
+static const struct bmi088_accel_chip_info bmi088_accel_chip_info_tbl[] = {
+ [0] = {
+ .name = "bmi088a",
+ .chip_id = 0x1E,
+ .channels = bmi088_accel_channels,
+ .num_channels = ARRAY_SIZE(bmi088_accel_channels),
+ },
+};
+
+static const struct iio_info bmi088_accel_info = {
+ .attrs = &bmi088_accel_attrs_group,
+ .read_raw = bmi088_accel_read_raw,
+ .write_raw = bmi088_accel_write_raw,
+};
+
+static const unsigned long bmi088_accel_scan_masks[] = {
+ BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z),
+ 0
+};
+
+static int bmi088_accel_chip_init(struct bmi088_accel_data *data)
+{
+ struct device *dev = regmap_get_device(data->regmap);
+ int ret, i;
+ unsigned int val;
+
+ /* Do a dummy read to enable SPI interface, won't harm I2C */
+ regmap_read(data->regmap, BMI088_ACCEL_REG_INT_STATUS, &val);
+
+ /*
+ * Reset chip to get it in a known good state. A delay of 1ms after
+ * reset is required according to the data sheet
+ */
+ ret = regmap_write(data->regmap, BMI088_ACCEL_REG_RESET,
+ BMI088_ACCEL_RESET_VAL);
+ if (ret)
+ return ret;
+
+ usleep_range(1000, 2000);
+
+ /* Do a dummy read again after a reset to enable the SPI interface */
+ regmap_read(data->regmap, BMI088_ACCEL_REG_INT_STATUS, &val);
+
+ /* Read chip ID */
+ ret = regmap_read(data->regmap, BMI088_ACCEL_REG_CHIP_ID, &val);
+ if (ret) {
+ dev_err(dev, "Error: Reading chip id\n");
+ return ret;
+ }
+
+ /* Validate chip ID */
+ for (i = 0; i < ARRAY_SIZE(bmi088_accel_chip_info_tbl); i++) {
+ if (bmi088_accel_chip_info_tbl[i].chip_id == val) {
+ data->chip_info = &bmi088_accel_chip_info_tbl[i];
+ break;
+ }
+ }
+ if (i == ARRAY_SIZE(bmi088_accel_chip_info_tbl)) {
+ dev_err(dev, "Invalid chip %x\n", val);
+ return -ENODEV;
+ }
+
+ /* Enable accelerometer after reset */
+ return bmi088_accel_enable(data, true);
+}
+
+int bmi088_accel_core_probe(struct device *dev, struct regmap *regmap,
+ int irq, const char *name, bool block_supported)
+{
+ struct bmi088_accel_data *data;
+ struct iio_dev *indio_dev;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ data = iio_priv(indio_dev);
+ dev_set_drvdata(dev, indio_dev);
+
+ data->regmap = regmap;
+
+ ret = bmi088_accel_chip_init(data);
+ if (ret)
+ return ret;
+
+ mutex_init(&data->mutex);
+
+ indio_dev->dev.parent = dev;
+ indio_dev->channels = data->chip_info->channels;
+ indio_dev->num_channels = data->chip_info->num_channels;
+ indio_dev->name = name ? name : data->chip_info->name;
+ indio_dev->available_scan_masks = bmi088_accel_scan_masks;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->info = &bmi088_accel_info;
+
+ ret = pm_runtime_set_active(dev);
+ if (ret)
+ return ret;
+
+ pm_runtime_enable(dev);
+ pm_runtime_set_autosuspend_delay(dev, BMI088_AUTO_SUSPEND_DELAY_MS);
+ pm_runtime_use_autosuspend(dev);
+
+ ret = iio_device_register(indio_dev);
+ if (ret)
+ dev_err(dev, "Unable to register iio device\n");
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(bmi088_accel_core_probe);
+
+int bmi088_accel_core_remove(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct bmi088_accel_data *data = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+
+ pm_runtime_disable(dev);
+ pm_runtime_set_suspended(dev);
+ pm_runtime_put_noidle(dev);
+
+ mutex_lock(&data->mutex);
+ bmi088_accel_set_mode(data, BMI088_ACCEL_MODE_SUSPEND);
+ mutex_unlock(&data->mutex);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(bmi088_accel_core_remove);
+
+/* When going into system sleep, put the chip in power down */
+static int __maybe_unused bmi088_accel_suspend(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct bmi088_accel_data *data = iio_priv(indio_dev);
+
+ mutex_lock(&data->mutex);
+ bmi088_accel_set_mode(data, BMI088_ACCEL_MODE_SUSPEND);
+ bmi088_accel_enable(data, false);
+ mutex_unlock(&data->mutex);
+
+ return 0;
+}
+
+static int __maybe_unused bmi088_accel_resume(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct bmi088_accel_data *data = iio_priv(indio_dev);
+
+ mutex_lock(&data->mutex);
+ bmi088_accel_enable(data, true);
+ bmi088_accel_set_mode(data, BMI088_ACCEL_MODE_ACTIVE);
+ mutex_unlock(&data->mutex);
+
+ return 0;
+}
+
+/* For runtime PM put the chip in suspend mode */
+static int __maybe_unused bmi088_accel_runtime_suspend(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct bmi088_accel_data *data = iio_priv(indio_dev);
+
+ return bmi088_accel_set_mode(data, BMI088_ACCEL_MODE_SUSPEND);
+}
+
+static int __maybe_unused bmi088_accel_runtime_resume(struct device *dev)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct bmi088_accel_data *data = iio_priv(indio_dev);
+ int ret;
+
+ ret = bmi088_accel_set_mode(data, BMI088_ACCEL_MODE_ACTIVE);
+ if (ret)
+ return ret;
+
+ usleep_range(BMI088_ACCEL_MAX_STARTUP_TIME_US,
+ BMI088_ACCEL_MAX_STARTUP_TIME_US * 2);
+
+ return 0;
+}
+
+const struct dev_pm_ops bmi088_accel_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(bmi088_accel_suspend, bmi088_accel_resume)
+ SET_RUNTIME_PM_OPS(bmi088_accel_runtime_suspend,
+ bmi088_accel_runtime_resume, NULL)
+};
+EXPORT_SYMBOL_GPL(bmi088_accel_pm_ops);
+
+MODULE_AUTHOR("Niek van Agt <niek.van.agt@xxxxxxxxxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("BMI088 accelerometer driver (core)");
diff --git a/drivers/iio/accel/bmi088-accel-spi.c b/drivers/iio/accel/bmi088-accel-spi.c
new file mode 100644
index 000000000000..7794090b8e6d
--- /dev/null
+++ b/drivers/iio/accel/bmi088-accel-spi.c
@@ -0,0 +1,85 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * 3-axis accelerometer driver supporting following Bosch-Sensortec chips:
+ * - BMI088
+ *
+ * Copyright (c) 2018-2020, Topic Embedded Products
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/spi/spi.h>
+#include <linux/regmap.h>
+
+#include "bmi088-accel.h"
+
+int bmi088_regmap_spi_write(void *context, const void *data, size_t count)
+{
+ struct spi_device *spi = context;
+
+ /* Write register is same as generic SPI */
+ return spi_write(spi, data, count);
+}
+
+int bmi088_regmap_spi_read(void *context, const void *reg,
+ size_t reg_size, void *val, size_t val_size)
+{
+ struct spi_device *spi = context;
+ u8 addr[2];
+
+ addr[0] = *(u8 *)reg;
+ addr[0] |= BIT(7); /* Set RW = '1' */
+ addr[1] = 0; /* Read requires a dummy byte transfer */
+
+ return spi_write_then_read(spi, addr, sizeof(addr), val, val_size);
+}
+
+static struct regmap_bus bmi088_regmap_bus = {
+ .write = bmi088_regmap_spi_write,
+ .read = bmi088_regmap_spi_read,
+ .reg_format_endian_default = REGMAP_ENDIAN_BIG,
+ .val_format_endian_default = REGMAP_ENDIAN_BIG,
+};
+
+static int bmi088_accel_probe(struct spi_device *spi)
+{
+ struct regmap *regmap;
+ const struct spi_device_id *id = spi_get_device_id(spi);
+
+ regmap = devm_regmap_init(&spi->dev, &bmi088_regmap_bus,
+ spi, &bmi088_regmap_conf);
+
+ if (IS_ERR(regmap)) {
+ dev_err(&spi->dev, "Failed to initialize spi regmap\n");
+ return PTR_ERR(regmap);
+ }
+
+ return bmi088_accel_core_probe(&spi->dev, regmap, spi->irq, id->name,
+ true);
+}
+
+static int bmi088_accel_remove(struct spi_device *spi)
+{
+ return bmi088_accel_core_remove(&spi->dev);
+}
+
+static const struct spi_device_id bmi088_accel_id[] = {
+ {"bmi088_accel", },
+ {}
+};
+MODULE_DEVICE_TABLE(spi, bmi088_accel_id);
+
+static struct spi_driver bmi088_accel_driver = {
+ .driver = {
+ .name = "bmi088_accel_spi",
+ .pm = &bmi088_accel_pm_ops,
+ },
+ .probe = bmi088_accel_probe,
+ .remove = bmi088_accel_remove,
+ .id_table = bmi088_accel_id,
+};
+module_spi_driver(bmi088_accel_driver);
+
+MODULE_AUTHOR("Niek van Agt <niek.van.agt@xxxxxxxxxxxxxxxxx>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("BMI088 accelerometer driver (SPI)");
diff --git a/drivers/iio/accel/bmi088-accel.h b/drivers/iio/accel/bmi088-accel.h
new file mode 100644
index 000000000000..5c25f16b672c
--- /dev/null
+++ b/drivers/iio/accel/bmi088-accel.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef BMI088_ACCEL_H
+#define BMI088_ACCEL_H
+
+#include <linux/pm.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+
+struct device;
+
+extern const struct regmap_config bmi088_regmap_conf;
+extern const struct dev_pm_ops bmi088_accel_pm_ops;
+
+int bmi088_accel_core_probe(struct device *dev, struct regmap *regmap, int irq,
+ const char *name, bool block_supported);
+int bmi088_accel_core_remove(struct device *dev);
+
+#endif /* BMI088_ACCEL_H */
--
2.17.1