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Date:   Thu,  7 May 2020 16:42:19 +0200
From:   Jean-Baptiste Maneyrol <jmaneyrol@...ensense.com>
To:     jic23@...nel.org, robh+dt@...nel.org, robh@...nel.org,
        mchehab+huawei@...nel.org, davem@...emloft.net,
        gregkh@...uxfoundation.org
Cc:     linux-iio@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Jean-Baptiste Maneyrol <jmaneyrol@...ensense.com>
Subject: [PATCH 09/12] iio: imu: inv_icm42600: add buffer support in iio devices

Use triggered buffer by parsing FIFO data read in device trigger.
Support hwfifo watermark by multiplexing gyro and accel settings.
Support hwfifo flush.

Simply use interrupt timestamp first.

Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@...ensense.com>
---
 drivers/iio/imu/inv_icm42600/Kconfig          |   3 +-
 drivers/iio/imu/inv_icm42600/Makefile         |   1 +
 drivers/iio/imu/inv_icm42600/inv_icm42600.h   |   8 +
 .../iio/imu/inv_icm42600/inv_icm42600_accel.c | 183 +++++++++
 .../imu/inv_icm42600/inv_icm42600_buffer.c    | 353 ++++++++++++++++++
 .../imu/inv_icm42600/inv_icm42600_buffer.h    | 162 ++++++++
 .../iio/imu/inv_icm42600/inv_icm42600_core.c  |  23 ++
 .../iio/imu/inv_icm42600/inv_icm42600_gyro.c  | 183 +++++++++
 .../imu/inv_icm42600/inv_icm42600_trigger.c   |  15 +-
 9 files changed, 928 insertions(+), 3 deletions(-)
 create mode 100644 drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.c
 create mode 100644 drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.h

diff --git a/drivers/iio/imu/inv_icm42600/Kconfig b/drivers/iio/imu/inv_icm42600/Kconfig
index 7b3eaeb2aa4a..8c0969319c49 100644
--- a/drivers/iio/imu/inv_icm42600/Kconfig
+++ b/drivers/iio/imu/inv_icm42600/Kconfig
@@ -2,7 +2,8 @@
 
 config INV_ICM42600
 	tristate
-	select IIO_TRIGGER
+	select IIO_BUFFER
+	select IIO_TRIGGERED_BUFFER
 
 config INV_ICM42600_I2C
 	tristate "InvenSense ICM-426xx I2C driver"
diff --git a/drivers/iio/imu/inv_icm42600/Makefile b/drivers/iio/imu/inv_icm42600/Makefile
index e1f2aacbe888..d6732118010c 100644
--- a/drivers/iio/imu/inv_icm42600/Makefile
+++ b/drivers/iio/imu/inv_icm42600/Makefile
@@ -6,6 +6,7 @@ inv-icm42600-y += inv_icm42600_gyro.o
 inv-icm42600-y += inv_icm42600_accel.o
 inv-icm42600-y += inv_icm42600_temp.o
 inv-icm42600-y += inv_icm42600_trigger.o
+inv-icm42600-y += inv_icm42600_buffer.o
 
 obj-$(CONFIG_INV_ICM42600_I2C) += inv-icm42600-i2c.o
 inv-icm42600-i2c-y += inv_icm42600_i2c.o
diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600.h b/drivers/iio/imu/inv_icm42600/inv_icm42600.h
index 175c1f67faee..947ca4dd245b 100644
--- a/drivers/iio/imu/inv_icm42600/inv_icm42600.h
+++ b/drivers/iio/imu/inv_icm42600/inv_icm42600.h
@@ -15,6 +15,8 @@
 #include <linux/iio/iio.h>
 #include <linux/iio/trigger.h>
 
+#include "inv_icm42600_buffer.h"
+
 enum inv_icm42600_chip {
 	INV_CHIP_ICM42600,
 	INV_CHIP_ICM42602,
@@ -124,6 +126,7 @@ struct inv_icm42600_suspended {
  *  @indio_gyro:	gyroscope IIO device.
  *  @indio_accel:	accelerometer IIO device.
  *  @trigger:		device internal interrupt trigger
+ *  @fifo:		FIFO management structure.
  */
 struct inv_icm42600_state {
 	struct mutex lock;
@@ -138,6 +141,7 @@ struct inv_icm42600_state {
 	struct iio_dev *indio_gyro;
 	struct iio_dev *indio_accel;
 	struct iio_trigger *trigger;
+	struct inv_icm42600_fifo fifo;
 };
 
 /* Virtual register addresses: @bank on MSB (4 upper bits), @address on LSB */
@@ -378,8 +382,12 @@ int inv_icm42600_core_probe(struct regmap *regmap, int chip, int irq,
 
 int inv_icm42600_gyro_init(struct inv_icm42600_state *st);
 
+int inv_icm42600_gyro_parse_fifo(struct iio_dev *indio_dev, int64_t ts);
+
 int inv_icm42600_accel_init(struct inv_icm42600_state *st);
 
+int inv_icm42600_accel_parse_fifo(struct iio_dev *indio_dev, int64_t ts);
+
 int inv_icm42600_trigger_init(struct inv_icm42600_state *st, int irq,
 			      int irq_type);
 
diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600_accel.c b/drivers/iio/imu/inv_icm42600/inv_icm42600_accel.c
index 74dac5f283d4..4206be54d057 100644
--- a/drivers/iio/imu/inv_icm42600/inv_icm42600_accel.c
+++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_accel.c
@@ -10,9 +10,13 @@
 #include <linux/regmap.h>
 #include <linux/delay.h>
 #include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
 
 #include "inv_icm42600.h"
 #include "inv_icm42600_temp.h"
+#include "inv_icm42600_buffer.h"
 
 #define INV_ICM42600_ACCEL_CHAN(_modifier, _index, _ext_info)		\
 	{								\
@@ -46,6 +50,7 @@ enum inv_icm42600_accel_scan {
 	INV_ICM42600_ACCEL_SCAN_Y,
 	INV_ICM42600_ACCEL_SCAN_Z,
 	INV_ICM42600_ACCEL_SCAN_TEMP,
+	INV_ICM42600_ACCEL_SCAN_TIMESTAMP,
 };
 
 static const struct iio_chan_spec_ext_info inv_icm42600_accel_ext_infos[] = {
@@ -61,8 +66,100 @@ static const struct iio_chan_spec inv_icm42600_accel_channels[] = {
 	INV_ICM42600_ACCEL_CHAN(IIO_MOD_Z, INV_ICM42600_ACCEL_SCAN_Z,
 				inv_icm42600_accel_ext_infos),
 	INV_ICM42600_TEMP_CHAN(INV_ICM42600_ACCEL_SCAN_TEMP),
+	IIO_CHAN_SOFT_TIMESTAMP(INV_ICM42600_ACCEL_SCAN_TIMESTAMP),
 };
 
+/* IIO buffer data */
+struct inv_icm42600_accel_buffer {
+	struct inv_icm42600_fifo_sensor_data accel;
+	int8_t temp;
+	int64_t timestamp;
+};
+
+#define INV_ICM42600_SCAN_MASK_ACCEL_3AXIS				\
+	(BIT(INV_ICM42600_ACCEL_SCAN_X) |				\
+	BIT(INV_ICM42600_ACCEL_SCAN_Y) |				\
+	BIT(INV_ICM42600_ACCEL_SCAN_Z))
+
+#define INV_ICM42600_SCAN_MASK_TEMP	BIT(INV_ICM42600_ACCEL_SCAN_TEMP)
+
+static const unsigned long inv_icm42600_accel_scan_masks[] = {
+	/* 3-axis accel + temperature */
+	INV_ICM42600_SCAN_MASK_ACCEL_3AXIS | INV_ICM42600_SCAN_MASK_TEMP,
+	0,
+};
+
+static irqreturn_t inv_icm42600_accel_handler(int irq, void *_data)
+{
+	struct iio_poll_func *pf = _data;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
+	const size_t fifo_nb = st->fifo.nb.total;
+	int ret;
+
+	/* exit if no sample */
+	if (fifo_nb == 0)
+		goto out;
+
+	ret = inv_icm42600_accel_parse_fifo(indio_dev, pf->timestamp);
+	if (ret)
+		dev_err(regmap_get_device(st->map), "accel fifo error %d\n",
+			ret);
+
+out:
+	iio_trigger_notify_done(indio_dev->trig);
+	return IRQ_HANDLED;
+}
+
+/* enable accelerometer sensor and FIFO write */
+static int inv_icm42600_accel_update_scan_mode(struct iio_dev *indio_dev,
+					       const unsigned long *scan_mask)
+{
+	struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
+	struct inv_icm42600_sensor_conf conf = INV_ICM42600_SENSOR_CONF_INIT;
+	unsigned int fifo_en = 0;
+	unsigned int sleep_temp = 0;
+	unsigned int sleep_accel = 0;
+	unsigned int sleep;
+	int ret;
+
+	mutex_lock(&st->lock);
+
+	if (*scan_mask & INV_ICM42600_SCAN_MASK_TEMP) {
+		/* enable temp sensor */
+		ret = inv_icm42600_set_temp_conf(st, true, &sleep_temp);
+		if (ret)
+			goto out_unlock;
+		fifo_en |= INV_ICM42600_SENSOR_TEMP;
+	}
+
+	if (*scan_mask & INV_ICM42600_SCAN_MASK_ACCEL_3AXIS) {
+		/* enable accel sensor */
+		conf.mode = INV_ICM42600_SENSOR_MODE_LOW_NOISE;
+		ret = inv_icm42600_set_accel_conf(st, &conf, &sleep_accel);
+		if (ret)
+			goto out_unlock;
+		fifo_en |= INV_ICM42600_SENSOR_ACCEL;
+	}
+
+	/* update data FIFO write and FIFO watermark */
+	ret = inv_icm42600_buffer_set_fifo_en(st, fifo_en | st->fifo.en);
+	if (ret)
+		goto out_unlock;
+	ret = inv_icm42600_buffer_update_watermark(st);
+
+out_unlock:
+	mutex_unlock(&st->lock);
+	/* sleep maximum required time */
+	if (sleep_accel > sleep_temp)
+		sleep = sleep_accel;
+	else
+		sleep = sleep_temp;
+	if (sleep)
+		msleep(sleep);
+	return ret;
+}
+
 static int inv_icm42600_accel_read_sensor(struct inv_icm42600_state *st,
 					  struct iio_chan_spec const *chan,
 					  int16_t *val)
@@ -250,6 +347,8 @@ static int inv_icm42600_accel_write_odr(struct inv_icm42600_state *st,
 	mutex_lock(&st->lock);
 	conf.odr = inv_icm42600_accel_odr_conv[idx / 2];
 	ret = inv_icm42600_set_accel_conf(st, &conf, NULL);
+	inv_icm42600_buffer_update_fifo_period(st);
+	inv_icm42600_buffer_update_watermark(st);
 	mutex_unlock(&st->lock);
 
 	pm_runtime_mark_last_busy(dev);
@@ -512,12 +611,51 @@ static int inv_icm42600_accel_write_raw_get_fmt(struct iio_dev *indio_dev,
 	}
 }
 
+static int inv_icm42600_accel_hwfifo_set_watermark(struct iio_dev *indio_dev,
+						   unsigned int val)
+{
+	struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
+	int ret;
+
+	mutex_lock(&st->lock);
+
+	st->fifo.watermark.accel = val;
+	ret = inv_icm42600_buffer_update_watermark(st);
+
+	mutex_unlock(&st->lock);
+
+	return ret;
+}
+
+static int inv_icm42600_accel_hwfifo_flush(struct iio_dev *indio_dev,
+					   unsigned int count)
+{
+	struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
+	int ret;
+
+	if (count == 0)
+		return 0;
+
+	mutex_lock(&st->lock);
+
+	ret = inv_icm42600_buffer_hwfifo_flush(st, count);
+	if (!ret)
+		ret = st->fifo.nb.accel;
+
+	mutex_unlock(&st->lock);
+
+	return ret;
+}
+
 static const struct iio_info inv_icm42600_accel_info = {
 	.read_raw = inv_icm42600_accel_read_raw,
 	.read_avail = inv_icm42600_accel_read_avail,
 	.write_raw = inv_icm42600_accel_write_raw,
 	.write_raw_get_fmt = inv_icm42600_accel_write_raw_get_fmt,
 	.debugfs_reg_access = inv_icm42600_debugfs_reg,
+	.update_scan_mode = inv_icm42600_accel_update_scan_mode,
+	.hwfifo_set_watermark = inv_icm42600_accel_hwfifo_set_watermark,
+	.hwfifo_flush_to_buffer = inv_icm42600_accel_hwfifo_flush,
 };
 
 int inv_icm42600_accel_init(struct inv_icm42600_state *st)
@@ -525,6 +663,7 @@ int inv_icm42600_accel_init(struct inv_icm42600_state *st)
 	struct device *dev = regmap_get_device(st->map);
 	const char *name;
 	struct iio_dev *indio_dev;
+	int ret;
 
 	name = devm_kasprintf(dev, GFP_KERNEL, "%s-accel", st->name);
 	if (!name)
@@ -541,7 +680,51 @@ int inv_icm42600_accel_init(struct inv_icm42600_state *st)
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = inv_icm42600_accel_channels;
 	indio_dev->num_channels = ARRAY_SIZE(inv_icm42600_accel_channels);
+	indio_dev->available_scan_masks = inv_icm42600_accel_scan_masks;
+
+	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
+					      inv_icm42600_accel_handler,
+					      &inv_icm42600_buffer_ops);
+	if (ret)
+		return ret;
+
+	indio_dev->trig = iio_trigger_get(st->trigger);
 
 	st->indio_accel = indio_dev;
 	return devm_iio_device_register(dev, st->indio_accel);
 }
+
+int inv_icm42600_accel_parse_fifo(struct iio_dev *indio_dev, int64_t ts)
+{
+	struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
+	const size_t accel_nb = st->fifo.nb.accel;
+	ssize_t i, size;
+	const void *accel, *gyro, *temp, *timestamp;
+	unsigned int odr;
+	struct inv_icm42600_accel_buffer buffer;
+
+	/* exit if no accel sample */
+	if (accel_nb == 0)
+		return 0;
+
+	/* parse all fifo packets */
+	for (i = 0; i < st->fifo.count; i += size) {
+		size = inv_icm42600_fifo_decode_packet(&st->fifo.data[i],
+				&accel, &gyro, &temp, &timestamp, &odr);
+		dev_dbg(regmap_get_device(st->map), "accel packet size = %zd\n",
+			size);
+		/* quit if error or FIFO is empty */
+		if (size <= 0)
+			return size;
+		/* skip packet if no accel data or data is invalid */
+		if (accel == NULL || !inv_icm42600_fifo_is_data_valid(accel)) {
+			dev_dbg(regmap_get_device(st->map), "skip accel data\n");
+			continue;
+		}
+		memcpy(&buffer.accel, accel, sizeof(buffer.accel));
+		memcpy(&buffer.temp, temp, sizeof(buffer.temp));
+		iio_push_to_buffers_with_timestamp(indio_dev, &buffer, ts);
+	}
+
+	return 0;
+}
diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.c b/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.c
new file mode 100644
index 000000000000..b428abdc92ee
--- /dev/null
+++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.c
@@ -0,0 +1,353 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2020 Invensense, Inc.
+ */
+
+#include <linux/device.h>
+#include <linux/mutex.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/delay.h>
+#include <linux/math64.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+
+#include "inv_icm42600.h"
+#include "inv_icm42600_buffer.h"
+
+void inv_icm42600_buffer_update_fifo_period(struct inv_icm42600_state *st)
+{
+	uint32_t period_gyro, period_accel, period;
+
+	if (st->fifo.en & INV_ICM42600_SENSOR_GYRO)
+		period_gyro = inv_icm42600_odr_to_period(st->conf.gyro.odr);
+	else
+		period_gyro = U32_MAX;
+
+	if (st->fifo.en & INV_ICM42600_SENSOR_ACCEL)
+		period_accel = inv_icm42600_odr_to_period(st->conf.accel.odr);
+	else
+		period_accel = U32_MAX;
+
+	if (period_gyro <= period_accel)
+		period = period_gyro;
+	else
+		period = period_accel;
+
+	st->fifo.period = period;
+}
+
+int inv_icm42600_buffer_set_fifo_en(struct inv_icm42600_state *st,
+				    unsigned int fifo_en)
+{
+	unsigned int mask, val;
+	int ret;
+
+	/* update only FIFO EN bits */
+	mask = INV_ICM42600_FIFO_CONFIG1_TMST_FSYNC_EN |
+		INV_ICM42600_FIFO_CONFIG1_TEMP_EN |
+		INV_ICM42600_FIFO_CONFIG1_GYRO_EN |
+		INV_ICM42600_FIFO_CONFIG1_ACCEL_EN;
+
+	val = 0;
+	if (fifo_en & INV_ICM42600_SENSOR_GYRO)
+		val |= INV_ICM42600_FIFO_CONFIG1_GYRO_EN;
+	if (fifo_en & INV_ICM42600_SENSOR_ACCEL)
+		val |= INV_ICM42600_FIFO_CONFIG1_ACCEL_EN;
+	if (fifo_en & INV_ICM42600_SENSOR_TEMP)
+		val |= INV_ICM42600_FIFO_CONFIG1_TEMP_EN;
+
+	ret = regmap_update_bits(st->map, INV_ICM42600_REG_FIFO_CONFIG1,
+				 mask, val);
+	if (ret)
+		return ret;
+
+	st->fifo.en = fifo_en;
+	inv_icm42600_buffer_update_fifo_period(st);
+
+	return 0;
+}
+
+static size_t inv_icm42600_get_packet_size(unsigned int fifo_en)
+{
+	size_t packet_size;
+
+	if ((fifo_en & INV_ICM42600_SENSOR_GYRO) &&
+			(fifo_en & INV_ICM42600_SENSOR_ACCEL))
+		packet_size = INV_ICM42600_FIFO_2SENSORS_PACKET_SIZE;
+	else
+		packet_size = INV_ICM42600_FIFO_1SENSOR_PACKET_SIZE;
+
+	return packet_size;
+}
+
+static unsigned int inv_icm42600_wm_truncate(unsigned int watermark,
+					     size_t packet_size)
+{
+	size_t wm_size;
+	unsigned int wm;
+
+	wm_size = watermark * packet_size;
+	if (wm_size > INV_ICM42600_FIFO_WATERMARK_MAX)
+		wm_size = INV_ICM42600_FIFO_WATERMARK_MAX;
+
+	wm = wm_size / packet_size;
+
+	return wm;
+}
+
+int inv_icm42600_buffer_update_watermark(struct inv_icm42600_state *st)
+{
+	size_t packet_size, wm_size;
+	unsigned int wm_gyro, wm_accel, watermark;
+	uint32_t period_gyro, period_accel, period;
+	int64_t latency_gyro, latency_accel, latency;
+	unsigned int mask, val;
+	bool restore;
+	__le16 raw_wm;
+	int ret;
+
+	packet_size = inv_icm42600_get_packet_size(st->fifo.en);
+
+	/* get minimal latency, depending on sensor watermark and odr */
+	wm_gyro = inv_icm42600_wm_truncate(st->fifo.watermark.gyro,
+					   packet_size);
+	wm_accel = inv_icm42600_wm_truncate(st->fifo.watermark.accel,
+					    packet_size);
+	period_gyro = inv_icm42600_odr_to_period(st->conf.gyro.odr);
+	period_accel = inv_icm42600_odr_to_period(st->conf.accel.odr);
+	latency_gyro = (int64_t)period_gyro * (int64_t)wm_gyro;
+	latency_accel = (int64_t)period_accel * (int64_t)wm_accel;
+	if (latency_gyro == 0) {
+		latency = latency_accel;
+		watermark = wm_accel;
+	} else if (latency_accel == 0) {
+		latency = latency_gyro;
+		watermark = wm_gyro;
+	} else {
+		/* compute the smallest latency that is a multiple of both */
+		if (latency_gyro <= latency_accel) {
+			latency = latency_gyro;
+			latency -= latency_accel % latency_gyro;
+		} else {
+			latency = latency_accel;
+			latency -= latency_gyro % latency_accel;
+		}
+		/* use the shortest period */
+		if (period_gyro <= period_accel)
+			period = period_gyro;
+		else
+			period = period_accel;
+		/* all this works because periods are multiple of each others */
+		watermark = div_s64(latency, period);
+		if (watermark < 1)
+			watermark = 1;
+	}
+	wm_size = watermark * packet_size;
+	dev_dbg(regmap_get_device(st->map), "watermark: %u (%zu)\n",
+		watermark, wm_size);
+
+	/* changing FIFO watermark requires to turn off watermark interrupt */
+	mask = INV_ICM42600_INT_SOURCE0_FIFO_THS_INT1_EN;
+	val = 0;
+	ret = regmap_update_bits_check(st->map, INV_ICM42600_REG_INT_SOURCE0,
+				       mask, val, &restore);
+	if (ret)
+		return ret;
+
+	raw_wm = INV_ICM42600_FIFO_WATERMARK_VAL(wm_size);
+	ret = regmap_bulk_write(st->map, INV_ICM42600_REG_FIFO_WATERMARK,
+				&raw_wm, sizeof(raw_wm));
+	if (ret)
+		return ret;
+
+	/* restore watermark interrupt */
+	if (restore) {
+		mask = INV_ICM42600_INT_SOURCE0_FIFO_THS_INT1_EN;
+		val = INV_ICM42600_INT_SOURCE0_FIFO_THS_INT1_EN;
+		ret = regmap_update_bits(st->map, INV_ICM42600_REG_INT_SOURCE0,
+					 mask, val);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int inv_icm42600_buffer_preenable(struct iio_dev *indio_dev)
+{
+	struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
+	struct device *dev = regmap_get_device(st->map);
+
+	pm_runtime_get_sync(dev);
+
+	return 0;
+}
+
+static int inv_icm42600_buffer_postdisable(struct iio_dev *indio_dev)
+{
+	struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
+	struct device *dev = regmap_get_device(st->map);
+	unsigned int sensor;
+	unsigned int *watermark;
+	struct inv_icm42600_sensor_conf conf = INV_ICM42600_SENSOR_CONF_INIT;
+	unsigned int sleep = 0;
+	int ret;
+
+	if (indio_dev == st->indio_gyro) {
+		sensor = INV_ICM42600_SENSOR_GYRO;
+		watermark = &st->fifo.watermark.gyro;
+	} else if (indio_dev == st->indio_accel) {
+		sensor = INV_ICM42600_SENSOR_ACCEL;
+		watermark = &st->fifo.watermark.accel;
+	} else {
+		return -EINVAL;
+	}
+
+	mutex_lock(&st->lock);
+
+	ret = inv_icm42600_buffer_set_fifo_en(st, st->fifo.en & ~sensor);
+	if (ret)
+		goto out_unlock;
+
+	*watermark = 0;
+	ret = inv_icm42600_buffer_update_watermark(st);
+	if (ret)
+		goto out_unlock;
+
+	conf.mode = INV_ICM42600_SENSOR_MODE_OFF;
+	if (sensor == INV_ICM42600_SENSOR_GYRO)
+		ret = inv_icm42600_set_gyro_conf(st, &conf, &sleep);
+	else
+		ret = inv_icm42600_set_accel_conf(st, &conf, &sleep);
+
+out_unlock:
+	mutex_unlock(&st->lock);
+	if (sleep)
+		msleep(sleep);
+	pm_runtime_mark_last_busy(dev);
+	pm_runtime_put_autosuspend(dev);
+
+	return ret;
+}
+
+const struct iio_buffer_setup_ops inv_icm42600_buffer_ops = {
+	.preenable = inv_icm42600_buffer_preenable,
+	.postenable = iio_triggered_buffer_postenable,
+	.predisable = iio_triggered_buffer_predisable,
+	.postdisable = inv_icm42600_buffer_postdisable,
+};
+
+int inv_icm42600_buffer_fifo_read(struct inv_icm42600_state *st,
+				  unsigned int max)
+{
+	struct device *dev = regmap_get_device(st->map);
+	__be16 raw_fifo_count;
+	size_t max_count;
+	ssize_t i, size;
+	const void *accel, *gyro, *temp, *timestamp;
+	unsigned int odr;
+	int ret;
+
+	/* reset all samples counters */
+	st->fifo.count = 0;
+	st->fifo.nb.gyro = 0;
+	st->fifo.nb.accel = 0;
+	st->fifo.nb.total = 0;
+
+	/* compute maximum FIFO read size */
+	if (max == 0)
+		max_count = sizeof(st->fifo.data);
+	else
+		max_count = max * inv_icm42600_get_packet_size(st->fifo.en);
+
+	/* read FIFO count value */
+	ret = regmap_bulk_read(st->map, INV_ICM42600_REG_FIFO_COUNT,
+			       &raw_fifo_count, sizeof(raw_fifo_count));
+	if (ret)
+		return ret;
+	st->fifo.count = be16_to_cpu(raw_fifo_count);
+	dev_dbg(dev, "FIFO count = %zu\n", st->fifo.count);
+
+	/* check and sanitize FIFO count value */
+	if (st->fifo.count == 0)
+		return 0;
+	if (st->fifo.count > max_count)
+		st->fifo.count = max_count;
+
+	/* read all FIFO data in internal buffer */
+	ret = regmap_noinc_read(st->map, INV_ICM42600_REG_FIFO_DATA,
+				st->fifo.data, st->fifo.count);
+	if (ret)
+		return ret;
+
+	/* compute number of samples for each sensor */
+	for (i = 0; i < st->fifo.count; i += size) {
+		size = inv_icm42600_fifo_decode_packet(&st->fifo.data[i],
+				&accel, &gyro, &temp, &timestamp, &odr);
+		if (size <= 0)
+			break;
+		if (gyro != NULL && inv_icm42600_fifo_is_data_valid(gyro))
+			st->fifo.nb.gyro++;
+		if (accel != NULL && inv_icm42600_fifo_is_data_valid(accel))
+			st->fifo.nb.accel++;
+		st->fifo.nb.total++;
+	}
+
+	return 0;
+}
+
+int inv_icm42600_buffer_hwfifo_flush(struct inv_icm42600_state *st,
+				     unsigned int count)
+{
+	int64_t ts_gyro, ts_accel;
+	int ret;
+
+	dev_dbg(regmap_get_device(st->map), "FIFO flush %u\n", count);
+
+	ts_gyro = iio_get_time_ns(st->indio_gyro);
+	ts_accel = iio_get_time_ns(st->indio_accel);
+	ret = inv_icm42600_buffer_fifo_read(st, count);
+	if (ret)
+		return ret;
+
+	if (st->fifo.nb.total == 0)
+		return 0;
+
+	ret = inv_icm42600_gyro_parse_fifo(st->indio_gyro, ts_gyro);
+	if (ret)
+		return ret;
+
+	return inv_icm42600_accel_parse_fifo(st->indio_accel, ts_accel);
+}
+
+int inv_icm42600_buffer_init(struct inv_icm42600_state *st)
+{
+	unsigned int mask, val;
+	int ret;
+
+	/*
+	 * Default FIFO configuration (bits 7 to 5)
+	 * - use invalid value
+	 * - FIFO count in bytes
+	 * - FIFO count in big endian
+	 */
+	mask = GENMASK(7, 5);
+	val = INV_ICM42600_INTF_CONFIG0_FIFO_COUNT_ENDIAN;
+	ret = regmap_update_bits(st->map, INV_ICM42600_REG_INTF_CONFIG0,
+				 mask, val);
+	if (ret)
+		return ret;
+
+	/*
+	 * Enable FIFO partial read and continuous watermark interrupt.
+	 * Disable all FIFO EN bits.
+	 */
+	mask = GENMASK(6, 5) | GENMASK(3, 0);
+	val = INV_ICM42600_FIFO_CONFIG1_RESUME_PARTIAL_RD |
+	      INV_ICM42600_FIFO_CONFIG1_WM_GT_TH;
+	return regmap_update_bits(st->map, INV_ICM42600_REG_FIFO_CONFIG1,
+				  mask, val);
+}
diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.h b/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.h
new file mode 100644
index 000000000000..74b91c0e664b
--- /dev/null
+++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_buffer.h
@@ -0,0 +1,162 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2020 Invensense, Inc.
+ */
+
+#ifndef INV_ICM42600_BUFFER_H_
+#define INV_ICM42600_BUFFER_H_
+
+#include <linux/kernel.h>
+#include <linux/bits.h>
+
+struct inv_icm42600_state;
+
+#define INV_ICM42600_SENSOR_GYRO	BIT(0)
+#define INV_ICM42600_SENSOR_ACCEL	BIT(1)
+#define INV_ICM42600_SENSOR_TEMP	BIT(2)
+
+struct inv_icm42600_fifo {
+	unsigned int en;
+	uint32_t period;
+	struct {
+		unsigned int gyro;
+		unsigned int accel;
+	} watermark;
+	size_t count;
+	struct {
+		size_t gyro;
+		size_t accel;
+		size_t total;
+	} nb;
+	uint8_t data[2080];
+};
+
+/* FIFO header: 1 byte */
+#define INV_ICM42600_FIFO_HEADER_MSG		BIT(7)
+#define INV_ICM42600_FIFO_HEADER_ACCEL		BIT(6)
+#define INV_ICM42600_FIFO_HEADER_GYRO		BIT(5)
+#define INV_ICM42600_FIFO_HEADER_TMST_FSYNC	GENMASK(3, 2)
+#define INV_ICM42600_FIFO_HEADER_ODR_ACCEL	BIT(1)
+#define INV_ICM42600_FIFO_HEADER_ODR_GYRO	BIT(0)
+
+/* FIFO data packet */
+struct inv_icm42600_fifo_sensor_data {
+	__be16 x;
+	__be16 y;
+	__be16 z;
+} __packed;
+#define INV_ICM42600_FIFO_DATA_INVALID		-32768
+
+struct inv_icm42600_fifo_1sensor_packet {
+	uint8_t header;
+	struct inv_icm42600_fifo_sensor_data data;
+	int8_t temp;
+} __packed;
+#define INV_ICM42600_FIFO_1SENSOR_PACKET_SIZE		8
+
+struct inv_icm42600_fifo_2sensors_packet {
+	uint8_t header;
+	struct inv_icm42600_fifo_sensor_data accel;
+	struct inv_icm42600_fifo_sensor_data gyro;
+	int8_t temp;
+	__be16 timestamp;
+} __packed;
+#define INV_ICM42600_FIFO_2SENSORS_PACKET_SIZE		16
+
+static inline int16_t inv_icm42600_fifo_get_sensor_data(__be16 d)
+{
+	return be16_to_cpu(d);
+}
+
+static inline bool
+inv_icm42600_fifo_is_data_valid(const struct inv_icm42600_fifo_sensor_data *s)
+{
+	int16_t x, y, z;
+
+	x = inv_icm42600_fifo_get_sensor_data(s->x);
+	y = inv_icm42600_fifo_get_sensor_data(s->y);
+	z = inv_icm42600_fifo_get_sensor_data(s->z);
+
+	if (x == INV_ICM42600_FIFO_DATA_INVALID &&
+			y == INV_ICM42600_FIFO_DATA_INVALID &&
+			z == INV_ICM42600_FIFO_DATA_INVALID)
+		return false;
+
+	return true;
+}
+
+static inline ssize_t inv_icm42600_fifo_decode_packet(const void *packet,
+		const void **accel, const void **gyro, const void **temp,
+		const void **timestamp, unsigned int *odr)
+{
+	const struct inv_icm42600_fifo_1sensor_packet *pack1 = packet;
+	const struct inv_icm42600_fifo_2sensors_packet *pack2 = packet;
+	uint8_t header = *((const uint8_t *)packet);
+
+	/* FIFO empty */
+	if (header & INV_ICM42600_FIFO_HEADER_MSG) {
+		*accel = NULL;
+		*gyro = NULL;
+		*temp = NULL;
+		*timestamp = NULL;
+		*odr = 0;
+		return 0;
+	}
+
+	/* handle odr flags */
+	*odr = 0;
+	if (header & INV_ICM42600_FIFO_HEADER_ODR_GYRO)
+		*odr |= INV_ICM42600_SENSOR_GYRO;
+	if (header & INV_ICM42600_FIFO_HEADER_ODR_ACCEL)
+		*odr |= INV_ICM42600_SENSOR_ACCEL;
+
+	/* accel + gyro */
+	if ((header & INV_ICM42600_FIFO_HEADER_ACCEL) &&
+			(header & INV_ICM42600_FIFO_HEADER_GYRO)) {
+		*accel = &pack2->accel;
+		*gyro = &pack2->gyro;
+		*temp = &pack2->temp;
+		*timestamp = &pack2->timestamp;
+		return INV_ICM42600_FIFO_2SENSORS_PACKET_SIZE;
+	}
+
+	/* accel only */
+	if (header & INV_ICM42600_FIFO_HEADER_ACCEL) {
+		*accel = &pack1->data;
+		*gyro = NULL;
+		*temp = &pack1->temp;
+		*timestamp = NULL;
+		return INV_ICM42600_FIFO_1SENSOR_PACKET_SIZE;
+	}
+
+	/* gyro only */
+	if (header & INV_ICM42600_FIFO_HEADER_GYRO) {
+		*accel = NULL;
+		*gyro = &pack1->data;
+		*temp = &pack1->temp;
+		*timestamp = NULL;
+		return INV_ICM42600_FIFO_1SENSOR_PACKET_SIZE;
+	}
+
+	/* invalid packet if here */
+	return -EINVAL;
+}
+
+extern const struct iio_buffer_setup_ops inv_icm42600_buffer_ops;
+
+int inv_icm42600_buffer_init(struct inv_icm42600_state *st);
+
+void inv_icm42600_buffer_update_fifo_period(struct inv_icm42600_state *st);
+
+int inv_icm42600_buffer_set_fifo_en(struct inv_icm42600_state *st,
+				    unsigned int fifo_en);
+
+int inv_icm42600_buffer_update_watermark(struct inv_icm42600_state *st);
+
+int inv_icm42600_buffer_fifo_read(struct inv_icm42600_state *st,
+				  unsigned int max);
+
+int inv_icm42600_buffer_hwfifo_flush(struct inv_icm42600_state *st,
+				     unsigned int count);
+
+#endif
diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600_core.c b/drivers/iio/imu/inv_icm42600/inv_icm42600_core.c
index 1102c54396e3..689089065ff9 100644
--- a/drivers/iio/imu/inv_icm42600/inv_icm42600_core.c
+++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_core.c
@@ -14,6 +14,7 @@
 #include <linux/iio/iio.h>
 
 #include "inv_icm42600.h"
+#include "inv_icm42600_buffer.h"
 
 static const struct regmap_range_cfg inv_icm42600_regmap_ranges[] = {
 	{
@@ -515,6 +516,11 @@ int inv_icm42600_core_probe(struct regmap *regmap, int chip, int irq,
 	if (ret)
 		return ret;
 
+	/* setup FIFO buffer */
+	ret = inv_icm42600_buffer_init(st);
+	if (ret)
+		return ret;
+
 	/* setup interrupt trigger */
 	ret = inv_icm42600_trigger_init(st, irq, irq_type);
 	if (ret)
@@ -559,6 +565,16 @@ static int __maybe_unused inv_icm42600_suspend(struct device *dev)
 		goto out_unlock;
 	}
 
+	/* disable FIFO data streaming */
+	if (iio_buffer_enabled(st->indio_gyro) ||
+			iio_buffer_enabled(st->indio_accel)) {
+		/* set FIFO in bypass mode */
+		ret = regmap_write(st->map, INV_ICM42600_REG_FIFO_CONFIG,
+				   INV_ICM42600_FIFO_CONFIG_BYPASS);
+		if (ret)
+			goto out_unlock;
+	}
+
 	ret = inv_icm42600_set_pwr_mgmt0(st, INV_ICM42600_SENSOR_MODE_OFF,
 					 INV_ICM42600_SENSOR_MODE_OFF, false,
 					 NULL);
@@ -594,6 +610,13 @@ static int __maybe_unused inv_icm42600_resume(struct device *dev)
 	if (ret)
 		goto out_unlock;
 
+	/* restore FIFO data streaming */
+	if (iio_buffer_enabled(st->indio_gyro) ||
+			iio_buffer_enabled(st->indio_accel)) {
+		ret = regmap_write(st->map, INV_ICM42600_REG_FIFO_CONFIG,
+				   INV_ICM42600_FIFO_CONFIG_STREAM);
+	}
+
 out_unlock:
 	mutex_unlock(&st->lock);
 	return ret;
diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600_gyro.c b/drivers/iio/imu/inv_icm42600/inv_icm42600_gyro.c
index c0164ab2830e..dafb104abc77 100644
--- a/drivers/iio/imu/inv_icm42600/inv_icm42600_gyro.c
+++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_gyro.c
@@ -10,9 +10,13 @@
 #include <linux/regmap.h>
 #include <linux/delay.h>
 #include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
 
 #include "inv_icm42600.h"
 #include "inv_icm42600_temp.h"
+#include "inv_icm42600_buffer.h"
 
 #define INV_ICM42600_GYRO_CHAN(_modifier, _index, _ext_info)		\
 	{								\
@@ -46,6 +50,7 @@ enum inv_icm42600_gyro_scan {
 	INV_ICM42600_GYRO_SCAN_Y,
 	INV_ICM42600_GYRO_SCAN_Z,
 	INV_ICM42600_GYRO_SCAN_TEMP,
+	INV_ICM42600_GYRO_SCAN_TIMESTAMP,
 };
 
 static const struct iio_chan_spec_ext_info inv_icm42600_gyro_ext_infos[] = {
@@ -61,8 +66,100 @@ static const struct iio_chan_spec inv_icm42600_gyro_channels[] = {
 	INV_ICM42600_GYRO_CHAN(IIO_MOD_Z, INV_ICM42600_GYRO_SCAN_Z,
 			       inv_icm42600_gyro_ext_infos),
 	INV_ICM42600_TEMP_CHAN(INV_ICM42600_GYRO_SCAN_TEMP),
+	IIO_CHAN_SOFT_TIMESTAMP(INV_ICM42600_GYRO_SCAN_TIMESTAMP),
 };
 
+/* IIO buffer data */
+struct inv_icm42600_gyro_buffer {
+	struct inv_icm42600_fifo_sensor_data gyro;
+	int8_t temp;
+	int64_t timestamp;
+};
+
+#define INV_ICM42600_SCAN_MASK_GYRO_3AXIS				\
+	(BIT(INV_ICM42600_GYRO_SCAN_X) |				\
+	BIT(INV_ICM42600_GYRO_SCAN_Y) |					\
+	BIT(INV_ICM42600_GYRO_SCAN_Z))
+
+#define INV_ICM42600_SCAN_MASK_TEMP	BIT(INV_ICM42600_GYRO_SCAN_TEMP)
+
+static const unsigned long inv_icm42600_gyro_scan_masks[] = {
+	/* 3-axis gyro + temperature */
+	INV_ICM42600_SCAN_MASK_GYRO_3AXIS | INV_ICM42600_SCAN_MASK_TEMP,
+	0,
+};
+
+static irqreturn_t inv_icm42600_gyro_handler(int irq, void *_data)
+{
+	struct iio_poll_func *pf = _data;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
+	const size_t fifo_nb = st->fifo.nb.total;
+	int ret;
+
+	/* exit if no sample */
+	if (fifo_nb == 0)
+		goto out;
+
+	ret = inv_icm42600_gyro_parse_fifo(indio_dev, pf->timestamp);
+	if (ret)
+		dev_err(regmap_get_device(st->map), "gyro fifo error %d\n",
+			ret);
+
+out:
+	iio_trigger_notify_done(indio_dev->trig);
+	return IRQ_HANDLED;
+}
+
+/* enable gyroscope sensor and FIFO write */
+static int inv_icm42600_gyro_update_scan_mode(struct iio_dev *indio_dev,
+					      const unsigned long *scan_mask)
+{
+	struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
+	struct inv_icm42600_sensor_conf conf = INV_ICM42600_SENSOR_CONF_INIT;
+	unsigned int fifo_en = 0;
+	unsigned int sleep_gyro = 0;
+	unsigned int sleep_temp = 0;
+	unsigned int sleep;
+	int ret;
+
+	mutex_lock(&st->lock);
+
+	if (*scan_mask & INV_ICM42600_SCAN_MASK_TEMP) {
+		/* enable temp sensor */
+		ret = inv_icm42600_set_temp_conf(st, true, &sleep_temp);
+		if (ret)
+			goto out_unlock;
+		fifo_en |= INV_ICM42600_SENSOR_TEMP;
+	}
+
+	if (*scan_mask & INV_ICM42600_SCAN_MASK_GYRO_3AXIS) {
+		/* enable gyro sensor */
+		conf.mode = INV_ICM42600_SENSOR_MODE_LOW_NOISE;
+		ret = inv_icm42600_set_gyro_conf(st, &conf, &sleep_gyro);
+		if (ret)
+			goto out_unlock;
+		fifo_en |= INV_ICM42600_SENSOR_GYRO;
+	}
+
+	/* update data FIFO write and FIFO watermark */
+	ret = inv_icm42600_buffer_set_fifo_en(st, fifo_en | st->fifo.en);
+	if (ret)
+		goto out_unlock;
+	ret = inv_icm42600_buffer_update_watermark(st);
+
+out_unlock:
+	mutex_unlock(&st->lock);
+	/* sleep maximum required time */
+	if (sleep_gyro > sleep_temp)
+		sleep = sleep_gyro;
+	else
+		sleep = sleep_temp;
+	if (sleep)
+		msleep(sleep);
+	return ret;
+}
+
 static int inv_icm42600_gyro_read_sensor(struct inv_icm42600_state *st,
 					 struct iio_chan_spec const *chan,
 					 int16_t *val)
@@ -262,6 +359,8 @@ static int inv_icm42600_gyro_write_odr(struct inv_icm42600_state *st,
 	mutex_lock(&st->lock);
 	conf.odr = inv_icm42600_gyro_odr_conv[idx / 2];
 	ret = inv_icm42600_set_gyro_conf(st, &conf, NULL);
+	inv_icm42600_buffer_update_fifo_period(st);
+	inv_icm42600_buffer_update_watermark(st);
 	mutex_unlock(&st->lock);
 
 	pm_runtime_mark_last_busy(dev);
@@ -524,12 +623,51 @@ static int inv_icm42600_gyro_write_raw_get_fmt(struct iio_dev *indio_dev,
 	}
 }
 
+static int inv_icm42600_gyro_hwfifo_set_watermark(struct iio_dev *indio_dev,
+						  unsigned int val)
+{
+	struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
+	int ret;
+
+	mutex_lock(&st->lock);
+
+	st->fifo.watermark.gyro = val;
+	ret = inv_icm42600_buffer_update_watermark(st);
+
+	mutex_unlock(&st->lock);
+
+	return ret;
+}
+
+static int inv_icm42600_gyro_hwfifo_flush(struct iio_dev *indio_dev,
+					  unsigned int count)
+{
+	struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
+	int ret;
+
+	if (count == 0)
+		return 0;
+
+	mutex_lock(&st->lock);
+
+	ret = inv_icm42600_buffer_hwfifo_flush(st, count);
+	if (!ret)
+		ret = st->fifo.nb.gyro;
+
+	mutex_unlock(&st->lock);
+
+	return ret;
+}
+
 static const struct iio_info inv_icm42600_gyro_info = {
 	.read_raw = inv_icm42600_gyro_read_raw,
 	.read_avail = inv_icm42600_gyro_read_avail,
 	.write_raw = inv_icm42600_gyro_write_raw,
 	.write_raw_get_fmt = inv_icm42600_gyro_write_raw_get_fmt,
 	.debugfs_reg_access = inv_icm42600_debugfs_reg,
+	.update_scan_mode = inv_icm42600_gyro_update_scan_mode,
+	.hwfifo_set_watermark = inv_icm42600_gyro_hwfifo_set_watermark,
+	.hwfifo_flush_to_buffer = inv_icm42600_gyro_hwfifo_flush,
 };
 
 int inv_icm42600_gyro_init(struct inv_icm42600_state *st)
@@ -537,6 +675,7 @@ int inv_icm42600_gyro_init(struct inv_icm42600_state *st)
 	struct device *dev = regmap_get_device(st->map);
 	const char *name;
 	struct iio_dev *indio_dev;
+	int ret;
 
 	name = devm_kasprintf(dev, GFP_KERNEL, "%s-gyro", st->name);
 	if (!name)
@@ -553,7 +692,51 @@ int inv_icm42600_gyro_init(struct inv_icm42600_state *st)
 	indio_dev->modes = INDIO_DIRECT_MODE;
 	indio_dev->channels = inv_icm42600_gyro_channels;
 	indio_dev->num_channels = ARRAY_SIZE(inv_icm42600_gyro_channels);
+	indio_dev->available_scan_masks = inv_icm42600_gyro_scan_masks;
+
+	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
+					      inv_icm42600_gyro_handler,
+					      &inv_icm42600_buffer_ops);
+	if (ret)
+		return ret;
+
+	indio_dev->trig = iio_trigger_get(st->trigger);
 
 	st->indio_gyro = indio_dev;
 	return devm_iio_device_register(dev, st->indio_gyro);
 }
+
+int inv_icm42600_gyro_parse_fifo(struct iio_dev *indio_dev, int64_t ts)
+{
+	struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
+	const size_t gyro_nb = st->fifo.nb.gyro;
+	ssize_t i, size;
+	const void *accel, *gyro, *temp, *timestamp;
+	unsigned int odr;
+	struct inv_icm42600_gyro_buffer buffer;
+
+	/* exit if no gyro sample */
+	if (gyro_nb == 0)
+		return 0;
+
+	/* parse all fifo packets */
+	for (i = 0; i < st->fifo.count; i += size) {
+		size = inv_icm42600_fifo_decode_packet(&st->fifo.data[i],
+				&accel, &gyro, &temp, &timestamp, &odr);
+		dev_dbg(regmap_get_device(st->map), "gyro packet size = %zd\n",
+			size);
+		/* quit if error or FIFO is empty */
+		if (size <= 0)
+			return size;
+		/* skip packet if no gyro data or data is invalid */
+		if (gyro == NULL || !inv_icm42600_fifo_is_data_valid(gyro)) {
+			dev_dbg(regmap_get_device(st->map), "skip gyro data\n");
+			continue;
+		}
+		memcpy(&buffer.gyro, gyro, sizeof(buffer.gyro));
+		memcpy(&buffer.temp, temp, sizeof(buffer.temp));
+		iio_push_to_buffers_with_timestamp(indio_dev, &buffer, ts);
+	}
+
+	return 0;
+}
diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600_trigger.c b/drivers/iio/imu/inv_icm42600/inv_icm42600_trigger.c
index 7a5e76305f0b..5667e0204722 100644
--- a/drivers/iio/imu/inv_icm42600/inv_icm42600_trigger.c
+++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_trigger.c
@@ -13,6 +13,7 @@
 #include <linux/iio/trigger_consumer.h>
 
 #include "inv_icm42600.h"
+#include "inv_icm42600_buffer.h"
 
 static irqreturn_t inv_icm42600_trigger_timestamp(int irq, void *_data)
 {
@@ -45,8 +46,18 @@ static irqreturn_t inv_icm42600_trigger_int_handler(int irq, void *_data)
 		dev_warn(dev, "FIFO full data lost!\n");
 
 	/* FIFO threshold reached */
-	if (status & INV_ICM42600_INT_STATUS_FIFO_THS)
-		iio_trigger_poll_chained(st->trigger);
+	if (status & INV_ICM42600_INT_STATUS_FIFO_THS) {
+		ret = inv_icm42600_buffer_fifo_read(st, 0);
+		if (ret)
+			dev_err(dev, "FIFO read error %d\n", ret);
+	} else {
+		st->fifo.count = 0;
+		st->fifo.nb.gyro = 0;
+		st->fifo.nb.accel = 0;
+		st->fifo.nb.total = 0;
+	}
+
+	iio_trigger_poll_chained(st->trigger);
 
 out_unlock:
 	mutex_unlock(&st->lock);
-- 
2.17.1

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