[PATCH v3 5/6] iio: imu: bmi270: Add triggered buffer for Bosch BMI270 IMU

Justin Weiss
2024-10-20T22:01:29Z

Set up a triggered buffer for the accel and angl_vel values.

Signed-off-by: Justin Weiss <justin@justinweiss.com>
---
drivers/iio/imu/bmi270/Kconfig | 1 +
drivers/iio/imu/bmi270/bmi270.h | 9 +++++
drivers/iio/imu/bmi270/bmi270_core.c | 56 ++++++++++++++++++++++++++++
3 files changed, 66 insertions(+)

diff --git a/drivers/iio/imu/bmi270/Kconfig b/drivers/iio/imu/bmi270/Kconfig
index 0ffd29794fda..6362acc706da 100644
--- a/drivers/iio/imu/bmi270/Kconfig
+++ b/drivers/iio/imu/bmi270/Kconfig
@@ -6,6 +6,7 @@
config BMI270
tristate
select IIO_BUFFER
+ select IIO_TRIGGERED_BUFFER

config BMI270_I2C
tristate "Bosch BMI270 I2C driver"
diff --git a/drivers/iio/imu/bmi270/bmi270.h b/drivers/iio/imu/bmi270/bmi270.h
index d8f6d7cf47fc..fdfad5784cc5 100644
--- a/drivers/iio/imu/bmi270/bmi270.h
+++ b/drivers/iio/imu/bmi270/bmi270.h
@@ -11,6 +11,15 @@ struct bmi270_data {
struct device *dev;
struct regmap *regmap;
const struct bmi270_chip_info *chip_info;
+
+ /*
+ * Where IIO_DMA_MINALIGN may be larger than 8 bytes, align to
+ * that to ensure a DMA safe buffer.
+ */
+ struct {
+ __le16 channels[6];
+ aligned_s64 timestamp;
+ } data __aligned(IIO_DMA_MINALIGN);
};

struct bmi270_chip_info {
diff --git a/drivers/iio/imu/bmi270/bmi270_core.c b/drivers/iio/imu/bmi270/bmi270_core.c
index 24e45d6f0706..5b643afae9f7 100644
--- a/drivers/iio/imu/bmi270/bmi270_core.c
+++ b/drivers/iio/imu/bmi270/bmi270_core.c
@@ -7,6 +7,8 @@
#include <linux/regmap.h>

#include <linux/iio/iio.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>

#include "bmi270.h"

@@ -70,6 +72,17 @@ enum bmi270_scan {
BMI270_SCAN_GYRO_X,
BMI270_SCAN_GYRO_Y,
BMI270_SCAN_GYRO_Z,
+ BMI270_SCAN_TIMESTAMP,
+};
+
+static const unsigned long bmi270_avail_scan_masks[] = {
+ (BIT(BMI270_SCAN_ACCEL_X) |
+ BIT(BMI270_SCAN_ACCEL_Y) |
+ BIT(BMI270_SCAN_ACCEL_Z) |
+ BIT(BMI270_SCAN_GYRO_X) |
+ BIT(BMI270_SCAN_GYRO_Y) |
+ BIT(BMI270_SCAN_GYRO_Z)),
+ 0
};

const struct bmi270_chip_info bmi260_chip_info = {
@@ -86,6 +99,27 @@ const struct bmi270_chip_info bmi270_chip_info = {
};
EXPORT_SYMBOL_NS_GPL(bmi270_chip_info, IIO_BMI270);

+static irqreturn_t bmi270_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct bmi270_data *bmi270_device = iio_priv(indio_dev);
+ int ret;
+
+ ret = regmap_bulk_read(bmi270_device->regmap, BMI270_ACCEL_X_REG,
+ &bmi270_device->data.channels,
+ sizeof(bmi270_device->data.channels));
+
+ if (ret)
+ goto done;
+
+ iio_push_to_buffers_with_timestamp(indio_dev, &bmi270_device->data,
+ pf->timestamp);
+done:
+ iio_trigger_notify_done(indio_dev->trig);
+ return IRQ_HANDLED;
+}
+
static int bmi270_get_data(struct bmi270_data *bmi270_device,
int chan_type, int axis, int *val)
{
@@ -141,6 +175,13 @@ static const struct iio_info bmi270_info = {
.modified = 1, \
.channel2 = IIO_MOD_##_axis, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .scan_index = BMI270_SCAN_ACCEL_##_axis, \
+ .scan_type = { \
+ .sign = 's', \
+ .realbits = 16, \
+ .storagebits = 16, \
+ .endianness = IIO_LE \
+ }, \
}

#define BMI270_ANG_VEL_CHANNEL(_axis) { \
@@ -148,6 +189,13 @@ static const struct iio_info bmi270_info = {
.modified = 1, \
.channel2 = IIO_MOD_##_axis, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
+ .scan_index = BMI270_SCAN_GYRO_##_axis, \
+ .scan_type = { \
+ .sign = 's', \
+ .realbits = 16, \
+ .storagebits = 16, \
+ .endianness = IIO_LE \
+ }, \
}

static const struct iio_chan_spec bmi270_channels[] = {
@@ -157,6 +205,7 @@ static const struct iio_chan_spec bmi270_channels[] = {
BMI270_ANG_VEL_CHANNEL(X),
BMI270_ANG_VEL_CHANNEL(Y),
BMI270_ANG_VEL_CHANNEL(Z),
+ IIO_CHAN_SOFT_TIMESTAMP(BMI270_SCAN_TIMESTAMP),
};

static int bmi270_validate_chip_id(struct bmi270_data *bmi270_device)
@@ -327,9 +376,16 @@ int bmi270_core_probe(struct device *dev, struct regmap *regmap,
indio_dev->channels = bmi270_channels;
indio_dev->num_channels = ARRAY_SIZE(bmi270_channels);
indio_dev->name = chip_info->name;
+ indio_dev->available_scan_masks = bmi270_avail_scan_masks;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->info = &bmi270_info;

+ ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
+ iio_pollfunc_store_time,
+ bmi270_trigger_handler, NULL);
+ if (ret)
+ return ret;
+
return devm_iio_device_register(dev, indio_dev);
}
EXPORT_SYMBOL_NS_GPL(bmi270_core_probe, IIO_BMI270);
--
2.47.0