sensor: icm45686: Add I2C bus support

Validated for read/decode APIs, as well as Streaming mode (FIFO).

Signed-off-by: Luis Ubieda <luisf@croxel.com>

drivers/sensor/tdk/icm45686/Kconfig

@@ -6,8 +6,10 @@ menuconfig ICM45686
 	bool "ICM45686 High-precision 6-Axis Motion Tracking Device"
 	default y
 	depends on DT_HAS_INVENSENSE_ICM45686_ENABLED
-	select SPI
+	select SPI if $(dt_compat_on_bus,$(DT_COMPAT_INVENSENSE_ICM45686),spi)
-	select SPI_RTIO
+	select SPI_RTIO if $(dt_compat_on_bus,$(DT_COMPAT_INVENSENSE_ICM45686),spi)
+	select I2C if $(dt_compat_on_bus,$(DT_COMPAT_INVENSENSE_ICM45686),i2c)
+	select I2C_RTIO if $(dt_compat_on_bus,$(DT_COMPAT_INVENSENSE_ICM45686),i2c)
 	help
 	  Enable driver for ICM45686 High-precision 6-axis motion
 	  tracking device.

drivers/sensor/tdk/icm45686/icm45686.c

@@ -10,6 +10,7 @@
 
 #include <zephyr/drivers/sensor.h>
 #include <zephyr/drivers/spi.h>
+#include <zephyr/drivers/i2c.h>
 #include <zephyr/drivers/gpio.h>
 #include <zephyr/rtio/rtio.h>
 
@@ -199,6 +200,9 @@ static inline void icm45686_submit_one_shot(const struct device *dev,
 			   edata->payload.buf,
 			   sizeof(edata->payload.buf),
 			   NULL);
+	if (data->rtio.type == ICM45686_BUS_I2C) {
+		read_sqe->iodev_flags |= RTIO_IODEV_I2C_STOP | RTIO_IODEV_I2C_RESTART;
+	}
 	read_sqe->flags |= RTIO_SQE_CHAINED;
 
 	rtio_sqe_prep_callback_no_cqe(complete_sqe,
@@ -245,10 +249,18 @@ static int icm45686_init(const struct device *dev)
 	uint8_t val;
 	int err;
 
-	if (!spi_is_ready_iodev(data->rtio.iodev)) {
+#if CONFIG_SPI_RTIO
+	if ((data->rtio.type == ICM45686_BUS_SPI) && !spi_is_ready_iodev(data->rtio.iodev)) {
 		LOG_ERR("Bus is not ready");
 		return -ENODEV;
 	}
+#endif
+#if CONFIG_I2C_RTIO
+	if ((data->rtio.type == ICM45686_BUS_I2C) && !i2c_is_ready_iodev(data->rtio.iodev)) {
+		LOG_ERR("Bus is not ready");
+		return -ENODEV;
+	}
+#endif
 
 	/* Soft-reset sensor to restore config to defaults */
 
@@ -383,10 +395,18 @@ static int icm45686_init(const struct device *dev)
 #define ICM45686_INIT(inst)									   \
 												   \
 	RTIO_DEFINE(icm45686_rtio_ctx_##inst, 8, 8);						   \
-	SPI_DT_IODEV_DEFINE(icm45686_bus_##inst,						   \
+												   \
+	COND_CODE_1(DT_INST_ON_BUS(inst, spi),							   \
+		    (SPI_DT_IODEV_DEFINE(icm45686_bus_##inst,					   \
 					 DT_DRV_INST(inst),					   \
 					 SPI_OP_MODE_MASTER | SPI_WORD_SET(8) | SPI_TRANSFER_MSB,  \
-			    0U);								   \
+					 0U)),							   \
+		    ());									   \
+												   \
+	COND_CODE_1(DT_INST_ON_BUS(inst, i2c),							   \
+		    (I2C_DT_IODEV_DEFINE(icm45686_bus_##inst,					   \
+					 DT_DRV_INST(inst))),					   \
+		    ());									   \
 												   \
 	static const struct icm45686_config icm45686_cfg_##inst = {				   \
 		.settings = {									   \
@@ -414,6 +434,10 @@ static int icm45686_init(const struct device *dev)
 		.rtio = {									   \
 			.iodev = &icm45686_bus_##inst,						   \
 			.ctx = &icm45686_rtio_ctx_##inst,					   \
+			COND_CODE_1(DT_INST_ON_BUS(inst, i2c),					   \
+				(.type = ICM45686_BUS_I2C), ())					   \
+				COND_CODE_1(DT_INST_ON_BUS(inst, spi),				   \
+				(.type = ICM45686_BUS_SPI), ())					   \
 		},										   \
 	};											   \
 												   \

drivers/sensor/tdk/icm45686/icm45686.h

@@ -130,10 +130,16 @@ struct icm45686_stream {
 	} data;
 };
 
+enum icm45686_bus_type {
+	ICM45686_BUS_SPI,
+	ICM45686_BUS_I2C,
+};
+
 struct icm45686_data {
 	struct {
 		struct rtio_iodev *iodev;
 		struct rtio *ctx;
+		enum icm45686_bus_type type;
 	} rtio;
 	/** Single-shot encoded data instance to support fetch/get API */
 	struct icm45686_encoded_data edata;

drivers/sensor/tdk/icm45686/icm45686_bus.h

@@ -36,6 +36,9 @@ static inline int icm45686_bus_read(const struct device *dev,
 	rtio_sqe_prep_write(write_sqe, iodev, RTIO_PRIO_HIGH, &reg, 1, NULL);
 	write_sqe->flags |= RTIO_SQE_TRANSACTION;
 	rtio_sqe_prep_read(read_sqe, iodev, RTIO_PRIO_HIGH, buf, len, NULL);
+	if (data->rtio.type == ICM45686_BUS_I2C) {
+		read_sqe->iodev_flags |= RTIO_IODEV_I2C_STOP | RTIO_IODEV_I2C_RESTART;
+	}
 
 	err = rtio_submit(ctx, 2);
 	if (err) {
@@ -73,6 +76,9 @@ static inline int icm45686_bus_write(const struct device *dev,
 	rtio_sqe_prep_write(write_reg_sqe, iodev, RTIO_PRIO_HIGH, &reg, 1, NULL);
 	write_reg_sqe->flags |= RTIO_SQE_TRANSACTION;
 	rtio_sqe_prep_write(write_buf_sqe, iodev, RTIO_PRIO_HIGH, buf, len, NULL);
+	if (data->rtio.type == ICM45686_BUS_I2C) {
+		write_buf_sqe->iodev_flags |= RTIO_IODEV_I2C_STOP;
+	}
 
 	err = rtio_submit(ctx, 2);
 	if (err) {

drivers/sensor/tdk/icm45686/icm45686_stream.c

@@ -204,6 +204,9 @@ static void icm45686_handle_event_actions(struct rtio *ctx,
 				   (buf->header.fifo_count *
 				   sizeof(struct icm45686_encoded_fifo_payload)),
 				   NULL);
+		if (data->rtio.type == ICM45686_BUS_I2C) {
+			data_rd_sqe->iodev_flags |= RTIO_IODEV_I2C_STOP | RTIO_IODEV_I2C_RESTART;
+		}
 		data_rd_sqe->flags |= RTIO_SQE_CHAINED;
 
 	} else if (should_flush_fifo(read_cfg, int_status)) {
@@ -232,6 +235,9 @@ static void icm45686_handle_event_actions(struct rtio *ctx,
 					 write_reg,
 					 sizeof(write_reg),
 					 NULL);
+		if (data->rtio.type == ICM45686_BUS_I2C) {
+			write_sqe->iodev_flags |= RTIO_IODEV_I2C_STOP;
+		}
 		write_sqe->flags |= RTIO_SQE_CHAINED;
 
 	} else if (should_read_data(read_cfg, int_status)) {
@@ -269,6 +275,9 @@ static void icm45686_handle_event_actions(struct rtio *ctx,
 				   buf->payload.buf,
 				   sizeof(buf->payload.buf),
 				   NULL);
+		if (data->rtio.type == ICM45686_BUS_I2C) {
+			read_sqe->iodev_flags |= RTIO_IODEV_I2C_STOP | RTIO_IODEV_I2C_RESTART;
+		}
 		read_sqe->flags |= RTIO_SQE_CHAINED;
 	}
 
@@ -318,6 +327,9 @@ static void icm45686_event_handler(const struct device *dev)
 					 wr_data,
 					 sizeof(wr_data),
 					 NULL);
+		if (data->rtio.type == ICM45686_BUS_I2C) {
+			write_sqe->iodev_flags |= RTIO_IODEV_I2C_STOP;
+		}
 		rtio_submit(data->rtio.ctx, 0);
 
 		data->stream.settings.enabled.drdy = false;
@@ -375,8 +387,12 @@ static void icm45686_event_handler(const struct device *dev)
 			   &data->stream.data.int_status,
 			   1,
 			   NULL);
+	if (data->rtio.type == ICM45686_BUS_I2C) {
+		read_sqe->iodev_flags |= RTIO_IODEV_I2C_STOP | RTIO_IODEV_I2C_RESTART;
+	}
 	read_sqe->flags |= RTIO_SQE_CHAINED;
 
+
 	/** Preemptively read FIFO count so we can decide on the next callback
 	 * how much FIFO data we'd read (if needed).
 	 */
@@ -395,6 +411,9 @@ static void icm45686_event_handler(const struct device *dev)
 			   (uint8_t *)&data->stream.data.fifo_count,
 			   2,
 			   NULL);
+	if (data->rtio.type == ICM45686_BUS_I2C) {
+		read_fifo_ct_sqe->iodev_flags |= RTIO_IODEV_I2C_STOP | RTIO_IODEV_I2C_RESTART;
+	}
 	read_fifo_ct_sqe->flags |= RTIO_SQE_CHAINED;
 
 	rtio_sqe_prep_callback_no_cqe(complete_sqe,

dts/bindings/sensor/invensense,icm45686-i2c.yaml

@@ -0,0 +1,30 @@
+# Copyright (c) 2025 Croxel Inc.
+# SPDX-License-Identifier: Apache-2.0
+
+description: |
+    ICM45686 High-precision 6-axis motion tracking device
+    When setting the accel-pm, accel-range, accel-odr, gyro-pm, gyro-range,
+    gyro-odr properties in a .dts or .dtsi file you may include icm45686.h
+    and use the macros defined there.
+
+    Example:
+    #include <zephyr/dt-bindings/sensor/icm45686.h>
+
+    &i2c0 {
+      ...
+
+      icm42688: icm45686@68 {
+        ...
+
+        accel-pwr-mode = <ICM45686_DT_ACCEL_LN>;
+        accel-fs = <ICM45686_DT_ACCEL_FS_32>;
+        accel-odr = <ICM45686_DT_ACCEL_ODR_800>;
+        gyro-pwr-mode= <ICM45686_DT_GYRO_LN>;
+        gyro-fs = <ICM45686_DT_GYRO_FS_4000>;
+        gyro-odr = <ICM45686_DT_GYRO_ODR_800>;
+      };
+    };
+
+compatible: "invensense,icm45686"
+
+include: ["i2c-device.yaml", "invensense,icm45686-common.yaml"]