sensor: icm45686: Add basic sensor functionality

- Add support for Fetch/Get API.
- Add support for Read/Decode API.
- Add config settings through device-tree.
- Add bus support for SPI (although easily extensible to others as
based on RTIO).

Fetch/Get API tested with accel_polling sample.
Read/Decode API tested with sensor_shell sample.

Signed-off-by: Luis Ubieda <[email protected]>

Author: ubieda

drivers/sensor/tdk/CMakeLists.txt

@@ -5,6 +5,7 @@
 add_subdirectory_ifdef(CONFIG_ICM42605 icm42605)
 add_subdirectory_ifdef(CONFIG_ICM42688 icm42688)
 add_subdirectory_ifdef(CONFIG_ICM42X70 icm42x70)
+add_subdirectory_ifdef(CONFIG_ICM45686 icm45686)
 add_subdirectory_ifdef(CONFIG_ICP101XX icp101xx)
 add_subdirectory_ifdef(CONFIG_MPU6050 mpu6050)
 add_subdirectory_ifdef(CONFIG_MPU9250 mpu9250)

drivers/sensor/tdk/Kconfig

@@ -5,6 +5,7 @@
 source "drivers/sensor/tdk/icm42605/Kconfig"
 source "drivers/sensor/tdk/icm42688/Kconfig"
 source "drivers/sensor/tdk/icm42x70/Kconfig"
+source "drivers/sensor/tdk/icm45686/Kconfig"
 source "drivers/sensor/tdk/icp101xx/Kconfig"
 source "drivers/sensor/tdk/mpu6050/Kconfig"
 source "drivers/sensor/tdk/mpu9250/Kconfig"

drivers/sensor/tdk/icm45686/CMakeLists.txt

@@ -0,0 +1,12 @@
+# Copyright (c) 2025 Croxel Inc.
+# Copyright (c) 2025 CogniPilot Foundation
+# SPDX-License-Identifier: Apache-2.0
+
+zephyr_library()
+zephyr_library_include_directories(.)
+zephyr_library_sources(
+	icm45686.c
+)
+zephyr_library_sources_ifdef(CONFIG_SENSOR_ASYNC_API
+	icm45686_decoder.c
+)

drivers/sensor/tdk/icm45686/Kconfig

@@ -0,0 +1,13 @@
+# Copyright (c) 2025 Croxel Inc.
+# Copyright (c) 2025 CogniPilot Foundation
+# SPDX-License-Identifier: Apache-2.0
+
+config ICM45686
+	bool "ICM45686 High-precision 6-Axis Motion Tracking Device"
+	default y
+	depends on DT_HAS_INVENSENSE_ICM45686_ENABLED
+	select SPI
+	select SPI_RTIO
+	help
+	  Enable driver for ICM45686 High-precision 6-axis motion
+	  tracking device.

drivers/sensor/tdk/icm45686/icm45686.c

@@ -0,0 +1,350 @@
+/*
+ * Copyright (c) 2022 Intel Corporation
+ * Copyright (c) 2025 Croxel Inc.
+ * Copyright (c) 2025 CogniPilot Foundation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT invensense_icm45686
+
+#include <zephyr/drivers/sensor.h>
+#include <zephyr/drivers/spi.h>
+#include <zephyr/drivers/gpio.h>
+#include <zephyr/rtio/rtio.h>
+
+#if defined(CONFIG_SENSOR_ASYNC_API)
+#include <zephyr/rtio/work.h>
+#endif /* CONFIG_SENSOR_ASYNC_API */
+
+#include "icm45686.h"
+#include "icm45686_reg.h"
+#include "icm45686_bus.h"
+#include "icm45686_decoder.h"
+
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(ICM45686, CONFIG_SENSOR_LOG_LEVEL);
+
+static inline int reg_write(const struct device *dev, uint8_t reg, uint8_t val)
+{
+	return icm45686_bus_write(dev, reg, &val, 1);
+}
+
+static inline int reg_read(const struct device *dev, uint8_t reg, uint8_t *val)
+{
+	return icm45686_bus_read(dev, reg, val, 1);
+}
+
+static inline int icm45686_fetch_data(const struct device *dev,
+				      struct icm45686_encoded_data *edata)
+{
+	int err;
+
+	err = icm45686_bus_read(dev,
+				REG_ACCEL_DATA_X1_UI,
+				edata->payload.buf,
+				sizeof(edata->payload.buf));
+
+	LOG_HEXDUMP_DBG(edata->payload.buf,
+			sizeof(edata->payload.buf),
+			"ICM45686 data");
+
+	return err;
+}
+
+static int icm45686_sample_fetch(const struct device *dev,
+				 enum sensor_channel chan)
+{
+	if (chan != SENSOR_CHAN_ALL) {
+		return -ENOTSUP;
+	}
+
+	struct icm45686_data *data = dev->data;
+
+	return icm45686_fetch_data(dev, &data->edata);
+}
+
+static int icm45686_channel_get(const struct device *dev,
+				enum sensor_channel chan,
+				struct sensor_value *val)
+{
+	struct icm45686_data *data = dev->data;
+
+	switch (chan) {
+	case SENSOR_CHAN_ACCEL_X:
+		icm45686_accel_ms(&data->edata, data->edata.payload.accel.x,
+				  &val->val1, &val->val2);
+		break;
+	case SENSOR_CHAN_ACCEL_Y:
+		icm45686_accel_ms(&data->edata, data->edata.payload.accel.y,
+				  &val->val1, &val->val2);
+		break;
+	case SENSOR_CHAN_ACCEL_Z:
+		icm45686_accel_ms(&data->edata, data->edata.payload.accel.z,
+				  &val->val1, &val->val2);
+		break;
+	case SENSOR_CHAN_GYRO_X:
+		icm45686_gyro_rads(&data->edata, data->edata.payload.gyro.x,
+				   &val->val1, &val->val2);
+		break;
+	case SENSOR_CHAN_GYRO_Y:
+		icm45686_gyro_rads(&data->edata, data->edata.payload.gyro.y,
+				   &val->val1, &val->val2);
+		break;
+	case SENSOR_CHAN_GYRO_Z:
+		icm45686_gyro_rads(&data->edata, data->edata.payload.gyro.z,
+				   &val->val1, &val->val2);
+		break;
+	case SENSOR_CHAN_DIE_TEMP:
+		icm45686_temp_c(data->edata.payload.temp, &val->val1, &val->val2);
+		break;
+	case SENSOR_CHAN_ACCEL_XYZ:
+		icm45686_accel_ms(&data->edata, data->edata.payload.accel.x,
+				  &val[0].val1, &val[0].val2);
+		icm45686_accel_ms(&data->edata, data->edata.payload.accel.y,
+				  &val[1].val1, &val[1].val2);
+		icm45686_accel_ms(&data->edata, data->edata.payload.accel.z,
+				  &val[2].val1, &val[2].val2);
+		break;
+	case SENSOR_CHAN_GYRO_XYZ:
+		icm45686_gyro_rads(&data->edata, data->edata.payload.gyro.x,
+				   &val->val1, &val->val2);
+		icm45686_gyro_rads(&data->edata, data->edata.payload.gyro.y,
+				   &val[1].val1, &val[1].val2);
+		icm45686_gyro_rads(&data->edata, data->edata.payload.gyro.z,
+				   &val[2].val1, &val[2].val2);
+		break;
+	default:
+		return -ENOTSUP;
+	}
+
+	return 0;
+}
+
+#if defined(CONFIG_SENSOR_ASYNC_API)
+
+static inline void icm45686_submit_one_shot(const struct device *dev,
+					    struct rtio_iodev_sqe *iodev_sqe)
+{
+	const struct sensor_read_config *cfg = iodev_sqe->sqe.iodev->data;
+	const struct sensor_chan_spec *const channels = cfg->channels;
+	const size_t num_channels = cfg->count;
+	uint32_t min_buf_len = sizeof(struct icm45686_encoded_data);
+	int err;
+	uint8_t *buf;
+	uint32_t buf_len;
+	struct icm45686_encoded_data *edata;
+
+	err = rtio_sqe_rx_buf(iodev_sqe, min_buf_len, min_buf_len, &buf, &buf_len);
+	if (err != 0) {
+		LOG_ERR("Failed to get a read buffer of size %u bytes", min_buf_len);
+		rtio_iodev_sqe_err(iodev_sqe, err);
+		return;
+	}
+
+	edata = (struct icm45686_encoded_data *)buf;
+
+	err = icm45686_encode(dev, channels, num_channels, buf);
+	if (err != 0) {
+		LOG_ERR("Failed to encode sensor data");
+		rtio_iodev_sqe_err(iodev_sqe, err);
+		return;
+	}
+
+	err = icm45686_fetch_data(dev, edata);
+	if (err != 0) {
+		LOG_ERR("Failed to fetch samples");
+		rtio_iodev_sqe_err(iodev_sqe, err);
+		return;
+	}
+
+	rtio_iodev_sqe_ok(iodev_sqe, 0);
+
+	LOG_DBG("One-shot fetch completed");
+}
+
+static void icm45686_submit_sync(struct rtio_iodev_sqe *iodev_sqe)
+{
+	const struct sensor_read_config *cfg = iodev_sqe->sqe.iodev->data;
+	const struct device *dev = cfg->sensor;
+
+	if (!cfg->is_streaming) {
+		icm45686_submit_one_shot(dev, iodev_sqe);
+	} else {
+		LOG_ERR("Streaming not supported");
+		rtio_iodev_sqe_err(iodev_sqe, -ENOTSUP);
+	}
+}
+
+static void icm45686_submit(const struct device *dev, struct rtio_iodev_sqe *iodev_sqe)
+{
+	struct rtio_work_req *req = rtio_work_req_alloc();
+
+	if (req == NULL) {
+		LOG_ERR("Failed to allocate RTIO work request");
+		rtio_iodev_sqe_err(iodev_sqe, -ENOMEM);
+		return;
+	}
+
+	rtio_work_req_submit(req, iodev_sqe, icm45686_submit_sync);
+}
+
+#endif /* CONFIG_SENSOR_ASYNC_API */
+
+static DEVICE_API(sensor, icm45686_driver_api) = {
+	.sample_fetch = icm45686_sample_fetch,
+	.channel_get = icm45686_channel_get,
+#if defined(CONFIG_SENSOR_ASYNC_API)
+	.get_decoder = icm45686_get_decoder,
+	.submit = icm45686_submit,
+#endif /* CONFIG_SENSOR_ASYNC_API */
+};
+
+static int icm45686_init(const struct device *dev)
+{
+	struct icm45686_data *data = dev->data;
+	const struct icm45686_config *cfg = dev->config;
+	uint8_t read_val = 0;
+	uint8_t val;
+	int err;
+
+	if (!spi_is_ready_iodev(data->rtio.iodev)) {
+		LOG_ERR("Bus is not ready");
+		return -ENODEV;
+	}
+
+	/* Soft-reset sensor to restore config to defaults */
+
+	err = reg_write(dev, REG_MISC2, REG_MISC2_SOFT_RST(1));
+	if (err) {
+		LOG_ERR("Failed to write soft-reset: %d", err);
+		return err;
+	}
+	/* Wait for soft-reset to take effect */
+	k_sleep(K_MSEC(1));
+
+	/* A complete soft-reset clears the bit */
+	err = reg_read(dev, REG_MISC2, &read_val);
+	if (err) {
+		LOG_ERR("Failed to read soft-reset: %d", err);
+		return err;
+	}
+	if ((read_val & REG_MISC2_SOFT_RST(1)) != 0) {
+		LOG_ERR("Soft-reset command failed");
+		return -EIO;
+	}
+
+	/* Set Slew-rate to 10-ns typical, to allow proper SPI readouts */
+
+	err = reg_write(dev, REG_DRIVE_CONFIG0, REG_DRIVE_CONFIG0_SPI_SLEW(2));
+	if (err) {
+		LOG_ERR("Failed to write slew-rate: %d", err);
+		return err;
+	}
+	/* Wait for register to take effect */
+	k_sleep(K_USEC(2));
+
+	/* Confirm ID Value matches */
+	err = reg_read(dev, REG_WHO_AM_I, &read_val);
+	if (err) {
+		LOG_ERR("Failed to read WHO_AM_I: %d", err);
+		return err;
+	}
+	if (read_val != WHO_AM_I_ICM45686) {
+		LOG_ERR("Unexpected WHO_AM_I value - expected: 0x%02x, actual: 0x%02x",
+			WHO_AM_I_ICM45686, read_val);
+		return -EIO;
+	}
+
+	/* Sensor Configuration */
+
+	val = REG_PWR_MGMT0_ACCEL_MODE(cfg->settings.accel.pwr_mode) |
+	      REG_PWR_MGMT0_GYRO_MODE(cfg->settings.gyro.pwr_mode);
+	err = reg_write(dev, REG_PWR_MGMT0, val);
+	if (err) {
+		LOG_ERR("Failed to write Power settings: %d", err);
+		return err;
+	}
+
+	val = REG_ACCEL_CONFIG0_ODR(cfg->settings.accel.odr) |
+	      REG_ACCEL_CONFIG0_FS(cfg->settings.accel.fs);
+	err = reg_write(dev, REG_ACCEL_CONFIG0, val);
+	if (err) {
+		LOG_ERR("Failed to write Accel settings: %d", err);
+		return err;
+	}
+
+	val = REG_GYRO_CONFIG0_ODR(cfg->settings.gyro.odr) |
+	      REG_GYRO_CONFIG0_FS(cfg->settings.gyro.fs);
+	err = reg_write(dev, REG_GYRO_CONFIG0, val);
+	if (err) {
+		LOG_ERR("Failed to write Gyro settings: %d", err);
+		return err;
+	}
+
+	LOG_DBG("Init OK");
+
+	return 0;
+}
+
+#define ICM45686_VALID_ACCEL_ODR(pwr_mode, odr)							   \
+	((pwr_mode == ICM45686_DT_ACCEL_LP && odr >= ICM45686_DT_ACCEL_ODR_400) ||		   \
+	 (pwr_mode == ICM45686_DT_ACCEL_LN && odr <= ICM45686_DT_ACCEL_ODR_12_5) ||		   \
+	 (pwr_mode == ICM45686_DT_ACCEL_OFF))
+
+#define ICM45686_VALID_GYRO_ODR(pwr_mode, odr)							   \
+	((pwr_mode == ICM45686_DT_GYRO_LP && odr >= ICM45686_DT_GYRO_ODR_400) ||		   \
+	 (pwr_mode == ICM45686_DT_GYRO_LN && odr <= ICM45686_DT_GYRO_ODR_12_5) ||		   \
+	 (pwr_mode == ICM45686_DT_GYRO_OFF))
+
+#define ICM45686_INIT(inst)									   \
+												   \
+	RTIO_DEFINE(icm45686_rtio_ctx_##inst, 8, 8);						   \
+	SPI_DT_IODEV_DEFINE(icm45686_bus_##inst,						   \
+			    DT_DRV_INST(inst),							   \
+			    SPI_OP_MODE_MASTER | SPI_WORD_SET(8) | SPI_TRANSFER_MSB,		   \
+			    0U);								   \
+												   \
+	static const struct icm45686_config icm45686_cfg_##inst = {				   \
+		.settings = {									   \
+			.accel = {								   \
+				.pwr_mode = DT_INST_PROP(inst, accel_pwr_mode),			   \
+				.fs = DT_INST_PROP(inst, accel_fs),				   \
+				.odr = DT_INST_PROP(inst, accel_odr),				   \
+			},									   \
+			.gyro = {								   \
+				.pwr_mode = DT_INST_PROP(inst, gyro_pwr_mode),			   \
+				.fs = DT_INST_PROP(inst, gyro_fs),				   \
+				.odr = DT_INST_PROP(inst, gyro_odr),				   \
+			},									   \
+		},										   \
+	};											   \
+	static struct icm45686_data icm45686_data_##inst = {					   \
+		.edata.header = {								   \
+			.is_fifo = false,							   \
+			.accel_fs = DT_INST_PROP(inst, accel_fs),				   \
+			.gyro_fs = DT_INST_PROP(inst, gyro_fs),					   \
+		},										   \
+		.rtio = {									   \
+			.iodev = &icm45686_bus_##inst,						   \
+			.ctx = &icm45686_rtio_ctx_##inst,					   \
+		},										   \
+	};											   \
+												   \
+	/* Build-time settings verification: Inform the user of invalid settings at build time */  \
+	BUILD_ASSERT(ICM45686_VALID_ACCEL_ODR(DT_INST_PROP(inst, accel_pwr_mode),		   \
+					      DT_INST_PROP(inst, accel_odr)),			   \
+		     "Invalid accel ODR setting. Please check supported ODRs for LP and LN");	   \
+	BUILD_ASSERT(ICM45686_VALID_GYRO_ODR(DT_INST_PROP(inst, gyro_pwr_mode),			   \
+					     DT_INST_PROP(inst, gyro_odr)),			   \
+		     "Invalid gyro ODR setting. Please check supported ODRs for LP and LN");	   \
+												   \
+	SENSOR_DEVICE_DT_INST_DEFINE(inst, icm45686_init,					   \
+				     NULL,							   \
+				     &icm45686_data_##inst,					   \
+				     &icm45686_cfg_##inst,					   \
+				     POST_KERNEL,						   \
+				     CONFIG_SENSOR_INIT_PRIORITY,				   \
+				     &icm45686_driver_api);
+
+DT_INST_FOREACH_STATUS_OKAY(ICM45686_INIT)