[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20250710-add_newport_driver-v2-3-bf76d8142ef2@tdk.com>
Date: Thu, 10 Jul 2025 08:57:58 +0000
From: Remi Buisson via B4 Relay <devnull+remi.buisson.tdk.com@...nel.org>
To: Jonathan Cameron <jic23@...nel.org>,
David Lechner <dlechner@...libre.com>,
Nuno Sá <nuno.sa@...log.com>,
Andy Shevchenko <andy@...nel.org>, Rob Herring <robh@...nel.org>,
Krzysztof Kozlowski <krzk+dt@...nel.org>,
Conor Dooley <conor+dt@...nel.org>
Cc: linux-kernel@...r.kernel.org, linux-iio@...r.kernel.org,
devicetree@...r.kernel.org, Remi Buisson <remi.buisson@....com>
Subject: [PATCH v2 3/8] iio: imu: inv_icm45600: add buffer support in iio
devices
From: Remi Buisson <remi.buisson@....com>
Add FIFO control functions.
Support hwfifo watermark by multiplexing gyro and accel settings.
Support hwfifo flush.
Signed-off-by: Remi Buisson <remi.buisson@....com>
---
drivers/iio/imu/inv_icm45600/Makefile | 1 +
drivers/iio/imu/inv_icm45600/inv_icm45600.h | 4 +
drivers/iio/imu/inv_icm45600/inv_icm45600_buffer.c | 514 +++++++++++++++++++++
drivers/iio/imu/inv_icm45600/inv_icm45600_buffer.h | 99 ++++
drivers/iio/imu/inv_icm45600/inv_icm45600_core.c | 137 +++++-
5 files changed, 754 insertions(+), 1 deletion(-)
diff --git a/drivers/iio/imu/inv_icm45600/Makefile b/drivers/iio/imu/inv_icm45600/Makefile
index 4f442b61896e91647c7947a044949792bae06a30..19c521ffba17b0d108a8ecb45ecdea35dff6fd18 100644
--- a/drivers/iio/imu/inv_icm45600/Makefile
+++ b/drivers/iio/imu/inv_icm45600/Makefile
@@ -2,3 +2,4 @@
obj-$(CONFIG_INV_ICM45600) += inv-icm45600.o
inv-icm45600-y += inv_icm45600_core.o
+inv-icm45600-y += inv_icm45600_buffer.o
\ No newline at end of file
diff --git a/drivers/iio/imu/inv_icm45600/inv_icm45600.h b/drivers/iio/imu/inv_icm45600/inv_icm45600.h
index d56de75ab7f2168f22e25b5816cb361bef457c0d..0b97c54f74b30aef3842e34da098c2443347de00 100644
--- a/drivers/iio/imu/inv_icm45600/inv_icm45600.h
+++ b/drivers/iio/imu/inv_icm45600/inv_icm45600.h
@@ -10,6 +10,8 @@
#include <linux/iio/iio.h>
#include <linux/types.h>
+#include "inv_icm45600_buffer.h"
+
#define INV_ICM45600_REG_BANK_MASK GENMASK(15, 8)
#define INV_ICM45600_REG_ADDR_MASK GENMASK(7, 0)
@@ -128,6 +130,7 @@ extern const struct inv_icm45600_chip_info inv_icm45689_chip_info;
* @indio_gyro: gyroscope IIO device.
* @indio_accel: accelerometer IIO device.
* @timestamp: interrupt timestamps.
+ * @fifo: FIFO management structure.
* @buffer: data transfer buffer aligned for DMA.
*/
struct inv_icm45600_state {
@@ -144,6 +147,7 @@ struct inv_icm45600_state {
s64 gyro;
s64 accel;
} timestamp;
+ struct inv_icm45600_fifo fifo;
union {
u8 buff[2];
__le16 u16;
diff --git a/drivers/iio/imu/inv_icm45600/inv_icm45600_buffer.c b/drivers/iio/imu/inv_icm45600/inv_icm45600_buffer.c
new file mode 100644
index 0000000000000000000000000000000000000000..a07affa0e3c64f84330071c92018438882cdf686
--- /dev/null
+++ b/drivers/iio/imu/inv_icm45600/inv_icm45600_buffer.c
@@ -0,0 +1,514 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Copyright (C) 2025 Invensense, Inc. */
+
+#include <linux/bitfield.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/common/inv_sensors_timestamp.h>
+#include <linux/iio/iio.h>
+#include <linux/mutex.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+
+#include "inv_icm45600_buffer.h"
+#include "inv_icm45600.h"
+
+/* FIFO header: 1 byte */
+#define INV_ICM45600_FIFO_EXT_HEADER BIT(7)
+#define INV_ICM45600_FIFO_HEADER_ACCEL BIT(6)
+#define INV_ICM45600_FIFO_HEADER_GYRO BIT(5)
+#define INV_ICM45600_FIFO_HEADER_HIGH_RES BIT(4)
+#define INV_ICM45600_FIFO_HEADER_TMST_FSYNC GENMASK(3, 2)
+#define INV_ICM45600_FIFO_HEADER_ODR_ACCEL BIT(1)
+#define INV_ICM45600_FIFO_HEADER_ODR_GYRO BIT(0)
+
+struct inv_icm45600_fifo_1sensor_packet {
+ u8 header;
+ struct inv_icm45600_fifo_sensor_data data;
+ s8 temp;
+} __packed;
+#define INV_ICM45600_FIFO_1SENSOR_PACKET_SIZE 8
+
+struct inv_icm45600_fifo_2sensors_packet {
+ u8 header;
+ struct inv_icm45600_fifo_sensor_data accel;
+ struct inv_icm45600_fifo_sensor_data gyro;
+ s8 temp;
+ __le16 timestamp;
+} __packed;
+#define INV_ICM45600_FIFO_2SENSORS_PACKET_SIZE 16
+
+ssize_t inv_icm45600_fifo_decode_packet(const void *packet,
+ const struct inv_icm45600_fifo_sensor_data **accel,
+ const struct inv_icm45600_fifo_sensor_data **gyro,
+ const s8 **temp,
+ const __le16 **timestamp, unsigned int *odr)
+{
+ const struct inv_icm45600_fifo_1sensor_packet *pack1 = packet;
+ const struct inv_icm45600_fifo_2sensors_packet *pack2 = packet;
+ u8 header = *((const u8 *)packet);
+
+ /* FIFO extended header */
+ if (header & INV_ICM45600_FIFO_EXT_HEADER) {
+ /* Not yet supported */
+ return 0;
+ }
+
+ /* handle odr flags. */
+ *odr = 0;
+ if (header & INV_ICM45600_FIFO_HEADER_ODR_GYRO)
+ *odr |= INV_ICM45600_SENSOR_GYRO;
+ if (header & INV_ICM45600_FIFO_HEADER_ODR_ACCEL)
+ *odr |= INV_ICM45600_SENSOR_ACCEL;
+
+ /* Accel + Gyro data are present. */
+ if ((header & INV_ICM45600_FIFO_HEADER_ACCEL) &&
+ (header & INV_ICM45600_FIFO_HEADER_GYRO)) {
+ *accel = &pack2->accel;
+ *gyro = &pack2->gyro;
+ *temp = &pack2->temp;
+ *timestamp = &pack2->timestamp;
+ return INV_ICM45600_FIFO_2SENSORS_PACKET_SIZE;
+ }
+
+ /* Accel data only. */
+ if (header & INV_ICM45600_FIFO_HEADER_ACCEL) {
+ *accel = &pack1->data;
+ *gyro = NULL;
+ *temp = &pack1->temp;
+ *timestamp = NULL;
+ return INV_ICM45600_FIFO_1SENSOR_PACKET_SIZE;
+ }
+
+ /* Gyro data only. */
+ if (header & INV_ICM45600_FIFO_HEADER_GYRO) {
+ *accel = NULL;
+ *gyro = &pack1->data;
+ *temp = &pack1->temp;
+ *timestamp = NULL;
+ return INV_ICM45600_FIFO_1SENSOR_PACKET_SIZE;
+ }
+
+ /* Invalid packet if here. */
+ return -EINVAL;
+}
+
+void inv_icm45600_buffer_update_fifo_period(struct inv_icm45600_state *st)
+{
+ u32 period_gyro, period_accel, period;
+
+ if (st->fifo.en & INV_ICM45600_SENSOR_GYRO)
+ period_gyro = inv_icm45600_odr_to_period(st->conf.gyro.odr);
+ else
+ period_gyro = U32_MAX;
+
+ if (st->fifo.en & INV_ICM45600_SENSOR_ACCEL)
+ period_accel = inv_icm45600_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_icm45600_buffer_set_fifo_en(struct inv_icm45600_state *st,
+ unsigned int fifo_en)
+{
+ unsigned int mask, val;
+ int ret;
+
+ /* Update only FIFO EN bits. */
+ mask = INV_ICM45600_FIFO_CONFIG3_GYRO_EN |
+ INV_ICM45600_FIFO_CONFIG3_ACCEL_EN;
+
+ val = 0;
+ if ((fifo_en & INV_ICM45600_SENSOR_GYRO) || (fifo_en & INV_ICM45600_SENSOR_ACCEL))
+ val = (INV_ICM45600_FIFO_CONFIG3_GYRO_EN | INV_ICM45600_FIFO_CONFIG3_ACCEL_EN);
+
+ ret = regmap_update_bits(st->map, INV_ICM45600_REG_FIFO_CONFIG3, mask, val);
+ if (ret)
+ return ret;
+
+ st->fifo.en = fifo_en;
+ inv_icm45600_buffer_update_fifo_period(st);
+
+ return 0;
+}
+
+static unsigned int inv_icm45600_wm_truncate(unsigned int watermark, size_t packet_size,
+ unsigned int fifo_period)
+{
+ size_t watermark_max, grace_samples;
+
+ /* Keep 20ms for processing FIFO. */
+ grace_samples = (20U * 1000000U) / fifo_period;
+ if (grace_samples < 1)
+ grace_samples = 1;
+
+ watermark_max = INV_ICM45600_FIFO_SIZE_MAX / packet_size;
+ watermark_max -= grace_samples;
+
+ if (watermark > watermark_max)
+ watermark = watermark_max;
+
+ return watermark;
+}
+
+/**
+ * inv_icm45600_buffer_update_watermark - update watermark FIFO threshold
+ * @st: driver internal state
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ *
+ * FIFO watermark threshold is computed based on the required watermark values
+ * set for gyro and accel sensors. Since watermark is all about acceptable data
+ * latency, use the smallest setting between the 2. It means choosing the
+ * smallest latency but this is not as simple as choosing the smallest watermark
+ * value. Latency depends on watermark and ODR. It requires several steps:
+ * 1) compute gyro and accel latencies and choose the smallest value.
+ * 2) adapt the chosen latency so that it is a multiple of both gyro and accel
+ * ones. Otherwise it is possible that you don't meet a requirement. (for
+ * example with gyro @100Hz wm 4 and accel @100Hz with wm 6, choosing the
+ * value of 4 will not meet accel latency requirement because 6 is not a
+ * multiple of 4. You need to use the value 2.)
+ * 3) Since all periods are multiple of each others, watermark is computed by
+ * dividing this computed latency by the smallest period, which corresponds
+ * to the FIFO frequency.
+ */
+int inv_icm45600_buffer_update_watermark(struct inv_icm45600_state *st)
+{
+ const size_t packet_size = INV_ICM45600_FIFO_2SENSORS_PACKET_SIZE;
+ unsigned int wm_gyro, wm_accel, watermark;
+ u32 period_gyro, period_accel, period;
+ u32 latency_gyro, latency_accel, latency;
+
+ /* Compute sensors latency, depending on sensor watermark and odr. */
+ wm_gyro = inv_icm45600_wm_truncate(st->fifo.watermark.gyro, packet_size,
+ st->fifo.period);
+ wm_accel = inv_icm45600_wm_truncate(st->fifo.watermark.accel, packet_size,
+ st->fifo.period);
+ /* Use us for odr to avoid overflow using 32 bits values. */
+ period_gyro = inv_icm45600_odr_to_period(st->conf.gyro.odr) / 1000UL;
+ period_accel = inv_icm45600_odr_to_period(st->conf.accel.odr) / 1000UL;
+ latency_gyro = period_gyro * wm_gyro;
+ latency_accel = period_accel * wm_accel;
+
+ /* 0 value for watermark means that the sensor is turned off. */
+ if (wm_gyro == 0 && wm_accel == 0)
+ return 0;
+
+ if (latency_gyro == 0) {
+ watermark = wm_accel;
+ st->fifo.watermark.eff_accel = wm_accel;
+ } else if (latency_accel == 0) {
+ watermark = wm_gyro;
+ st->fifo.watermark.eff_gyro = wm_gyro;
+ } else {
+ /* Compute the smallest latency that is a multiple of both. */
+ if (latency_gyro <= latency_accel)
+ latency = latency_gyro - (latency_accel % latency_gyro);
+ else
+ latency = latency_accel - (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 = latency / period;
+ if (watermark < 1)
+ watermark = 1;
+ /* Update effective watermark. */
+ st->fifo.watermark.eff_gyro = latency / period_gyro;
+ if (st->fifo.watermark.eff_gyro < 1)
+ st->fifo.watermark.eff_gyro = 1;
+ st->fifo.watermark.eff_accel = latency / period_accel;
+ if (st->fifo.watermark.eff_accel < 1)
+ st->fifo.watermark.eff_accel = 1;
+ }
+
+
+ st->buffer.u16 = cpu_to_le16(watermark);
+ return regmap_bulk_write(st->map, INV_ICM45600_REG_FIFO_WATERMARK,
+ &st->buffer.u16, sizeof(st->buffer.u16));
+}
+
+static int inv_icm45600_buffer_preenable(struct iio_dev *indio_dev)
+{
+ struct inv_icm45600_state *st = iio_device_get_drvdata(indio_dev);
+ struct device *dev = regmap_get_device(st->map);
+ struct inv_icm45600_sensor_state *sensor_st = iio_priv(indio_dev);
+ struct inv_sensors_timestamp *ts = &sensor_st->ts;
+ int ret;
+
+ ret = pm_runtime_resume_and_get(dev);
+ if (ret)
+ return ret;
+
+ guard(mutex)(&st->lock);
+ inv_sensors_timestamp_reset(ts);
+
+ return 0;
+}
+
+/*
+ * Update_scan_mode callback is turning sensors on and setting data FIFO enable
+ * bits.
+ */
+static int inv_icm45600_buffer_postenable(struct iio_dev *indio_dev)
+{
+ struct inv_icm45600_state *st = iio_device_get_drvdata(indio_dev);
+ unsigned int val;
+ int ret;
+
+ guard(mutex)(&st->lock);
+
+ /* Exit if FIFO is already on. */
+ if (st->fifo.on) {
+ /* Increase FIFO on counter. */
+ st->fifo.on++;
+ return 0;
+ }
+
+ /* Flush all FIFO data. */
+ ret = regmap_set_bits(st->map, INV_ICM45600_REG_FIFO_CONFIG2,
+ INV_ICM45600_REG_FIFO_CONFIG2_FIFO_FLUSH);
+ if (ret)
+ return ret;
+
+ /* Set FIFO threshold and full interrupt. */
+ ret = regmap_set_bits(st->map, INV_ICM45600_REG_INT1_CONFIG0,
+ INV_ICM45600_INT1_CONFIG0_FIFO_THS_EN |
+ INV_ICM45600_INT1_CONFIG0_FIFO_FULL_EN);
+ if (ret)
+ return ret;
+
+ /* Set FIFO in streaming mode. */
+ val = FIELD_PREP(INV_ICM45600_FIFO_CONFIG0_MODE_MASK,
+ INV_ICM45600_FIFO_CONFIG0_MODE_STREAM);
+ ret = regmap_update_bits(st->map, INV_ICM45600_REG_FIFO_CONFIG0,
+ INV_ICM45600_FIFO_CONFIG0_MODE_MASK, val);
+ if (ret)
+ return ret;
+
+ /* Enable writing sensor data to FIFO. */
+ ret = regmap_set_bits(st->map, INV_ICM45600_REG_FIFO_CONFIG3,
+ INV_ICM45600_FIFO_CONFIG3_IF_EN);
+ if (ret)
+ return ret;
+
+ /* Increase FIFO on counter. */
+ st->fifo.on++;
+ return 0;
+}
+
+static int inv_icm45600_buffer_predisable(struct iio_dev *indio_dev)
+{
+ struct inv_icm45600_state *st = iio_device_get_drvdata(indio_dev);
+ unsigned int val;
+ int ret;
+
+ guard(mutex)(&st->lock);
+
+ /* Exit if there are several sensors using the FIFO. */
+ if (st->fifo.on > 1) {
+ /* decrease FIFO on counter */
+ st->fifo.on--;
+ return 0;
+ }
+
+ /* Disable writing sensor data to FIFO. */
+ ret = regmap_clear_bits(st->map, INV_ICM45600_REG_FIFO_CONFIG3,
+ INV_ICM45600_FIFO_CONFIG3_IF_EN);
+ if (ret)
+ return ret;
+
+ /* Set FIFO in bypass mode. */
+ val = FIELD_PREP(INV_ICM45600_FIFO_CONFIG0_MODE_MASK,
+ INV_ICM45600_FIFO_CONFIG0_MODE_BYPASS);
+ ret = regmap_update_bits(st->map, INV_ICM45600_REG_FIFO_CONFIG0,
+ INV_ICM45600_FIFO_CONFIG0_MODE_MASK, val);
+ if (ret)
+ return ret;
+
+ /* Disable FIFO threshold and full interrupt. */
+ ret = regmap_clear_bits(st->map, INV_ICM45600_REG_INT1_CONFIG0,
+ INV_ICM45600_INT1_CONFIG0_FIFO_THS_EN |
+ INV_ICM45600_INT1_CONFIG0_FIFO_FULL_EN);
+ if (ret)
+ return ret;
+
+ /* Flush all FIFO data. */
+ ret = regmap_set_bits(st->map, INV_ICM45600_REG_FIFO_CONFIG2,
+ INV_ICM45600_REG_FIFO_CONFIG2_FIFO_FLUSH);
+ if (ret)
+ return ret;
+
+ /* Decrease FIFO on counter. */
+ st->fifo.on--;
+ return 0;
+}
+
+static int _inv_icm45600_buffer_postdisable(struct inv_icm45600_state *st,
+ unsigned int sensor, unsigned int *watermark,
+ unsigned int *sleep)
+{
+ struct inv_icm45600_sensor_conf conf = INV_ICM45600_SENSOR_CONF_INIT;
+ int ret;
+
+ ret = inv_icm45600_buffer_set_fifo_en(st, st->fifo.en & ~sensor);
+ if (ret)
+ return ret;
+
+ *watermark = 0;
+ ret = inv_icm45600_buffer_update_watermark(st);
+ if (ret)
+ return ret;
+
+ conf.mode = INV_ICM45600_SENSOR_MODE_OFF;
+ if (sensor == INV_ICM45600_SENSOR_GYRO)
+ ret = inv_icm45600_set_gyro_conf(st, &conf, sleep);
+ else
+ ret = inv_icm45600_set_accel_conf(st, &conf, sleep);
+
+ return ret;
+}
+
+static int inv_icm45600_buffer_postdisable(struct iio_dev *indio_dev)
+{
+ struct inv_icm45600_state *st = iio_device_get_drvdata(indio_dev);
+ struct device *dev = regmap_get_device(st->map);
+ unsigned int sensor;
+ unsigned int *watermark;
+ unsigned int sleep;
+ int ret;
+
+ if (indio_dev == st->indio_gyro) {
+ sensor = INV_ICM45600_SENSOR_GYRO;
+ watermark = &st->fifo.watermark.gyro;
+ } else if (indio_dev == st->indio_accel) {
+ sensor = INV_ICM45600_SENSOR_ACCEL;
+ watermark = &st->fifo.watermark.accel;
+ } else {
+ return -EINVAL;
+ }
+
+ scoped_guard(mutex, &st->lock)
+ ret = _inv_icm45600_buffer_postdisable(st, sensor, watermark, &sleep);
+
+ /* Sleep required time. */
+ if (sleep)
+ msleep(sleep);
+
+ pm_runtime_put_autosuspend(dev);
+
+ return ret;
+}
+
+const struct iio_buffer_setup_ops inv_icm45600_buffer_ops = {
+ .preenable = inv_icm45600_buffer_preenable,
+ .postenable = inv_icm45600_buffer_postenable,
+ .predisable = inv_icm45600_buffer_predisable,
+ .postdisable = inv_icm45600_buffer_postdisable,
+};
+
+int inv_icm45600_buffer_fifo_read(struct inv_icm45600_state *st,
+ unsigned int max)
+{
+ const ssize_t packet_size = INV_ICM45600_FIFO_2SENSORS_PACKET_SIZE;
+ __le16 *raw_fifo_count;
+ size_t fifo_nb, i;
+ ssize_t size;
+ const struct inv_icm45600_fifo_sensor_data *accel, *gyro;
+ const __le16 *timestamp;
+ const s8 *temp;
+ 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;
+
+ /* Read FIFO count value. */
+ raw_fifo_count = &st->buffer.u16;
+ ret = regmap_bulk_read(st->map, INV_ICM45600_REG_FIFO_COUNT,
+ raw_fifo_count, sizeof(*raw_fifo_count));
+ if (ret)
+ return ret;
+ fifo_nb = le16_to_cpup(raw_fifo_count);
+
+ /* Check and limit number of samples if requested. */
+ if (fifo_nb == 0)
+ return 0;
+ if (max > 0 && fifo_nb > max)
+ fifo_nb = max;
+
+ /* Try to read all FIFO data in internal buffer. */
+ st->fifo.count = fifo_nb * packet_size;
+ ret = regmap_noinc_read(st->map, INV_ICM45600_REG_FIFO_DATA,
+ st->fifo.data, st->fifo.count);
+ if (ret == -ENOTSUPP || ret == -EFBIG) {
+ /* Read full fifo is not supported, read samples one by one. */
+ ret = 0;
+ for (i = 0; i < st->fifo.count && ret == 0; i += packet_size)
+ ret = regmap_noinc_read(st->map, INV_ICM45600_REG_FIFO_DATA,
+ &st->fifo.data[i], packet_size);
+ }
+ if (ret)
+ return ret;
+
+ for (i = 0; i < st->fifo.count; i += size) {
+ size = inv_icm45600_fifo_decode_packet(&st->fifo.data[i],
+ &accel, &gyro, &temp, ×tamp, &odr);
+ if (size <= 0)
+ break;
+ if (gyro != NULL && inv_icm45600_fifo_is_data_valid(gyro))
+ st->fifo.nb.gyro++;
+ if (accel != NULL && inv_icm45600_fifo_is_data_valid(accel))
+ st->fifo.nb.accel++;
+ st->fifo.nb.total++;
+ }
+
+ return 0;
+}
+
+int inv_icm45600_buffer_init(struct inv_icm45600_state *st)
+{
+ int ret;
+ unsigned int val;
+
+ st->fifo.watermark.eff_gyro = 1;
+ st->fifo.watermark.eff_accel = 1;
+
+ /* Disable all FIFO EN bits. */
+ ret = regmap_write(st->map, INV_ICM45600_REG_FIFO_CONFIG3, 0);
+ if (ret)
+ return ret;
+
+ /* Disable FIFO and set depth. */
+ val = FIELD_PREP(INV_ICM45600_FIFO_CONFIG0_MODE_MASK,
+ INV_ICM45600_FIFO_CONFIG0_MODE_BYPASS);
+ val |= INV_ICM45600_FIFO_CONFIG0_FIFO_DEPTH_MAX;
+ ret = regmap_write(st->map, INV_ICM45600_REG_FIFO_CONFIG0, val);
+ if (ret)
+ return ret;
+
+ /* Enable only timestamp in fifo, disable compression. */
+ ret = regmap_write(st->map, INV_ICM45600_REG_FIFO_CONFIG4,
+ INV_ICM45600_FIFO_CONFIG4_TMST_FSYNC_EN);
+ if (ret)
+ return ret;
+
+ /* Enable FIFO continuous watermark interrupt. */
+ return regmap_set_bits(st->map, INV_ICM45600_REG_FIFO_CONFIG2,
+ INV_ICM45600_REG_FIFO_CONFIG2_WM_GT_TH);
+}
diff --git a/drivers/iio/imu/inv_icm45600/inv_icm45600_buffer.h b/drivers/iio/imu/inv_icm45600/inv_icm45600_buffer.h
new file mode 100644
index 0000000000000000000000000000000000000000..09595a41cf637a3ba9bc44e4df53a9d0aa11f485
--- /dev/null
+++ b/drivers/iio/imu/inv_icm45600/inv_icm45600_buffer.h
@@ -0,0 +1,99 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/* Copyright (C) 2025 Invensense, Inc. */
+
+#ifndef INV_ICM45600_BUFFER_H_
+#define INV_ICM45600_BUFFER_H_
+
+#include <linux/bits.h>
+#include <linux/iio/iio.h>
+#include <linux/types.h>
+
+struct inv_icm45600_state;
+
+#define INV_ICM45600_SENSOR_GYRO BIT(0)
+#define INV_ICM45600_SENSOR_ACCEL BIT(1)
+#define INV_ICM45600_SENSOR_TEMP BIT(2)
+
+/**
+ * struct inv_icm45600_fifo - FIFO state variables
+ * @on: reference counter for FIFO on.
+ * @en: bits field of INV_ICM45600_SENSOR_* for FIFO EN bits.
+ * @period: FIFO internal period.
+ * @watermark: watermark configuration values for accel and gyro.
+ * @count: number of bytes in the FIFO data buffer.
+ * @nb: gyro, accel and total samples in the FIFO data buffer.
+ * @data: FIFO data buffer aligned for DMA (8kB)
+ */
+struct inv_icm45600_fifo {
+ unsigned int on;
+ unsigned int en;
+ u32 period;
+ struct {
+ unsigned int gyro;
+ unsigned int accel;
+ unsigned int eff_gyro;
+ unsigned int eff_accel;
+ } watermark;
+ size_t count;
+ struct {
+ size_t gyro;
+ size_t accel;
+ size_t total;
+ } nb;
+ u8 data[8192] __aligned(IIO_DMA_MINALIGN);
+};
+
+/* FIFO data packet */
+struct inv_icm45600_fifo_sensor_data {
+ __le16 x;
+ __le16 y;
+ __le16 z;
+} __packed;
+#define INV_ICM45600_FIFO_DATA_INVALID -32768
+
+static inline s16 inv_icm45600_fifo_get_sensor_data(__le16 d)
+{
+ return le16_to_cpu(d);
+}
+
+static inline bool
+inv_icm45600_fifo_is_data_valid(const struct inv_icm45600_fifo_sensor_data *s)
+{
+ s16 x, y, z;
+
+ x = inv_icm45600_fifo_get_sensor_data(s->x);
+ y = inv_icm45600_fifo_get_sensor_data(s->y);
+ z = inv_icm45600_fifo_get_sensor_data(s->z);
+
+ if (x == INV_ICM45600_FIFO_DATA_INVALID &&
+ y == INV_ICM45600_FIFO_DATA_INVALID &&
+ z == INV_ICM45600_FIFO_DATA_INVALID)
+ return false;
+
+ return true;
+}
+
+ssize_t inv_icm45600_fifo_decode_packet(const void *packet,
+ const struct inv_icm45600_fifo_sensor_data **accel,
+ const struct inv_icm45600_fifo_sensor_data **gyro,
+ const s8 **temp,
+ const __le16 **timestamp, unsigned int *odr);
+
+extern const struct iio_buffer_setup_ops inv_icm45600_buffer_ops;
+
+int inv_icm45600_buffer_init(struct inv_icm45600_state *st);
+
+void inv_icm45600_buffer_update_fifo_period(struct inv_icm45600_state *st);
+
+int inv_icm45600_buffer_set_fifo_en(struct inv_icm45600_state *st,
+ unsigned int fifo_en);
+
+int inv_icm45600_buffer_update_watermark(struct inv_icm45600_state *st);
+
+int inv_icm45600_buffer_fifo_read(struct inv_icm45600_state *st,
+ unsigned int max);
+
+int inv_icm45600_buffer_hwfifo_flush(struct inv_icm45600_state *st,
+ unsigned int count);
+
+#endif
diff --git a/drivers/iio/imu/inv_icm45600/inv_icm45600_core.c b/drivers/iio/imu/inv_icm45600/inv_icm45600_core.c
index 022eb9180b5a750e8fba4a1cd873041c27f59880..37487e9174bf53f2fc6583f37ac7542ea31b0643 100644
--- a/drivers/iio/imu/inv_icm45600/inv_icm45600_core.c
+++ b/drivers/iio/imu/inv_icm45600/inv_icm45600_core.c
@@ -16,6 +16,7 @@
#include <linux/regulator/consumer.h>
#include <linux/types.h>
+#include "inv_icm45600_buffer.h"
#include "inv_icm45600.h"
static int inv_icm45600_ireg_read(struct regmap *map, unsigned int reg,
@@ -521,6 +522,95 @@ static int inv_icm45600_setup(struct inv_icm45600_state *st,
return inv_icm45600_set_conf(st, chip_info->conf);
}
+static irqreturn_t inv_icm45600_irq_timestamp(int irq, void *_data)
+{
+ struct inv_icm45600_state *st = _data;
+
+ st->timestamp.gyro = iio_get_time_ns(st->indio_gyro);
+ st->timestamp.accel = iio_get_time_ns(st->indio_accel);
+
+ return IRQ_WAKE_THREAD;
+}
+
+static irqreturn_t inv_icm45600_irq_handler(int irq, void *_data)
+{
+ struct inv_icm45600_state *st = _data;
+ struct device *dev = regmap_get_device(st->map);
+ unsigned int mask, status;
+ int ret;
+
+ guard(mutex)(&st->lock);
+
+ ret = regmap_read(st->map, INV_ICM45600_REG_INT_STATUS, &status);
+ if (ret)
+ return IRQ_HANDLED;
+
+ /* Read the FIFO data. */
+ mask = INV_ICM45600_INT_STATUS_FIFO_THS | INV_ICM45600_INT_STATUS_FIFO_FULL;
+ if (status & mask) {
+ ret = inv_icm45600_buffer_fifo_read(st, 0);
+ if (ret) {
+ dev_err(dev, "FIFO read error %d\n", ret);
+ return IRQ_HANDLED;
+ }
+ }
+
+ /* FIFO full warning. */
+ if (status & INV_ICM45600_INT_STATUS_FIFO_FULL)
+ dev_warn(dev, "FIFO full possible data lost!\n");
+
+ return IRQ_HANDLED;
+}
+
+/**
+ * inv_icm45600_irq_init() - initialize int pin and interrupt handler
+ * @st: driver internal state
+ * @irq: irq number
+ * @irq_type: irq trigger type
+ * @open_drain: true if irq is open drain, false for push-pull
+ *
+ * Returns 0 on success, a negative error code otherwise.
+ */
+static int inv_icm45600_irq_init(struct inv_icm45600_state *st, int irq,
+ int irq_type, bool open_drain)
+{
+ struct device *dev = regmap_get_device(st->map);
+ unsigned int val;
+ int ret;
+
+ /* Configure INT1 interrupt: default is active low on edge. */
+ switch (irq_type) {
+ case IRQF_TRIGGER_RISING:
+ case IRQF_TRIGGER_HIGH:
+ val = INV_ICM45600_INT1_CONFIG2_ACTIVE_HIGH;
+ break;
+ default:
+ val = INV_ICM45600_INT1_CONFIG2_ACTIVE_LOW;
+ break;
+ }
+
+ switch (irq_type) {
+ case IRQF_TRIGGER_LOW:
+ case IRQF_TRIGGER_HIGH:
+ val |= INV_ICM45600_INT1_CONFIG2_LATCHED;
+ break;
+ default:
+ break;
+ }
+
+ if (!open_drain)
+ val |= INV_ICM45600_INT1_CONFIG2_PUSH_PULL;
+
+ ret = regmap_write(st->map, INV_ICM45600_REG_INT1_CONFIG2, val);
+ if (ret)
+ return ret;
+
+ irq_type |= IRQF_ONESHOT;
+ return devm_request_threaded_irq(dev, irq, inv_icm45600_irq_timestamp,
+ inv_icm45600_irq_handler, irq_type,
+ "inv_icm45600", st);
+}
+
static int inv_icm45600_timestamp_setup(struct inv_icm45600_state *st)
{
/* Enable timestamps. */
@@ -627,6 +717,14 @@ int inv_icm45600_core_probe(struct regmap *regmap, const struct inv_icm45600_chi
if (ret)
return ret;
+ ret = inv_icm45600_buffer_init(st);
+ if (ret)
+ return ret;
+
+ ret = inv_icm45600_irq_init(st, irq, irq_type, open_drain);
+ if (ret)
+ return ret;
+
/* Setup runtime power management. */
ret = devm_pm_runtime_set_active_enabled(dev);
if (ret)
@@ -658,6 +756,22 @@ static int inv_icm45600_suspend(struct device *dev)
if (pm_runtime_suspended(dev))
return 0;
+ /* Disable FIFO data streaming. */
+ if (st->fifo.on) {
+ unsigned int val;
+
+ ret = regmap_clear_bits(st->map, INV_ICM45600_REG_FIFO_CONFIG3,
+ INV_ICM45600_FIFO_CONFIG3_IF_EN);
+ if (ret)
+ return ret;
+ val = FIELD_PREP(INV_ICM45600_FIFO_CONFIG0_MODE_MASK,
+ INV_ICM45600_FIFO_CONFIG0_MODE_BYPASS);
+ ret = regmap_update_bits(st->map, INV_ICM45600_REG_FIFO_CONFIG0,
+ INV_ICM45600_FIFO_CONFIG0_MODE_MASK, val);
+ if (ret)
+ return ret;
+ }
+
ret = inv_icm45600_set_pwr_mgmt0(st, INV_ICM45600_SENSOR_MODE_OFF,
INV_ICM45600_SENSOR_MODE_OFF, NULL);
if (ret)
@@ -675,6 +789,8 @@ static int inv_icm45600_suspend(struct device *dev)
static int inv_icm45600_resume(struct device *dev)
{
struct inv_icm45600_state *st = dev_get_drvdata(dev);
+ struct inv_icm45600_sensor_state *gyro_st = iio_priv(st->indio_gyro);
+ struct inv_icm45600_sensor_state *accel_st = iio_priv(st->indio_accel);
int ret;
guard(mutex)(&st->lock);
@@ -688,9 +804,28 @@ static int inv_icm45600_resume(struct device *dev)
pm_runtime_enable(dev);
/* Restore sensors state. */
- return inv_icm45600_set_pwr_mgmt0(st, st->suspended.gyro,
+ ret = inv_icm45600_set_pwr_mgmt0(st, st->suspended.gyro,
st->suspended.accel, NULL);
+ if (ret)
+ return ret;
+
+ /* Restore FIFO data streaming. */
+ if (st->fifo.on) {
+ unsigned int val;
+ inv_sensors_timestamp_reset(&gyro_st->ts);
+ inv_sensors_timestamp_reset(&accel_st->ts);
+ val = FIELD_PREP(INV_ICM45600_FIFO_CONFIG0_MODE_MASK,
+ INV_ICM45600_FIFO_CONFIG0_MODE_STREAM);
+ ret = regmap_update_bits(st->map, INV_ICM45600_REG_FIFO_CONFIG0,
+ INV_ICM45600_FIFO_CONFIG0_MODE_MASK, val);
+ if (ret)
+ return ret;
+ ret = regmap_set_bits(st->map, INV_ICM45600_REG_FIFO_CONFIG3,
+ INV_ICM45600_FIFO_CONFIG3_IF_EN);
+ }
+
+ return ret;
}
/* Runtime suspend will turn off sensors that are enabled by iio devices. */
--
2.34.1
Powered by blists - more mailing lists