iio: imu: bmi270: Add triggered buffer for Bosch BMI270 IMU

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

Signed-off-by: Justin Weiss <justin@justinweiss.com>
Link: https://patch.msgid.link/20241027172029.160134-2-justin@justinweiss.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

3 files changed, 66 insertions, 0 deletions

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 93e5f387607b..6173be929bac 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 5f08d786fa21..bcc8a139d884 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"
 
@@ -64,6 +66,17 @@ 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 bmi270_chip_info = {
@@ -73,6 +86,27 @@ 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)
 {
@@ -128,6 +162,13 @@ 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) {				\
@@ -135,6 +176,13 @@ 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[] = {
@@ -144,6 +192,7 @@ 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)
@@ -301,9 +350,16 @@ 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);