sensor: icm45686: Add low-pass filter configuration options

Both for Gyro and Accelerometer.

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

Author: ubieda

drivers/sensor/tdk/icm45686/icm45686.c

@@ -312,6 +312,38 @@ static int icm45686_init(const struct device *dev)
 		return err;
 	}
 
+	/** Write Low-pass filter settings through indirect register access */
+	uint8_t gyro_lpf_write_array[] = REG_IREG_PREPARE_WRITE_ARRAY(
+						REG_IPREG_SYS1_OFFSET,
+						REG_IPREG_SYS1_REG_172,
+						REG_IPREG_SYS1_REG_172_GYRO_LPFBW_SEL(
+							cfg->settings.gyro.lpf));
+
+	err = icm45686_bus_write(dev, REG_IREG_ADDR_15_8, gyro_lpf_write_array,
+				 sizeof(gyro_lpf_write_array));
+	if (err) {
+		LOG_ERR("Failed to set Gyro BW settings: %d", err);
+		return err;
+	}
+
+	/** Wait before indirect register write is made effective
+	 * before proceeding with next one.
+	 */
+	k_sleep(K_MSEC(1));
+
+	uint8_t accel_lpf_write_array[] = REG_IREG_PREPARE_WRITE_ARRAY(
+						REG_IPREG_SYS2_OFFSET,
+						REG_IPREG_SYS2_REG_131,
+						REG_IPREG_SYS2_REG_131_ACCEL_LPFBW_SEL(
+							cfg->settings.accel.lpf));
+
+	err = icm45686_bus_write(dev, REG_IREG_ADDR_15_8, accel_lpf_write_array,
+				 sizeof(accel_lpf_write_array));
+	if (err) {
+		LOG_ERR("Failed to set Accel BW settings: %d", err);
+		return err;
+	}
+
 	LOG_DBG("Init OK");
 
 	return 0;
@@ -341,11 +373,13 @@ static int icm45686_init(const struct device *dev)
 				.pwr_mode = DT_INST_PROP(inst, accel_pwr_mode),			   \
 				.fs = DT_INST_PROP(inst, accel_fs),				   \
 				.odr = DT_INST_PROP(inst, accel_odr),				   \
+				.lpf = DT_INST_PROP_OR(inst, accel_lpf, 0),			   \
 			},									   \
 			.gyro = {								   \
 				.pwr_mode = DT_INST_PROP(inst, gyro_pwr_mode),			   \
 				.fs = DT_INST_PROP(inst, gyro_fs),				   \
 				.odr = DT_INST_PROP(inst, gyro_odr),				   \
+				.lpf = DT_INST_PROP_OR(inst, gyro_lpf, 0),			   \
 			},									   \
 		},										   \
 	};											   \

drivers/sensor/tdk/icm45686/icm45686.h

@@ -63,11 +63,13 @@ struct icm45686_config {
 			uint8_t pwr_mode : 2;
 			uint8_t fs : 4;
 			uint8_t odr : 4;
+			uint8_t lpf : 3;
 		} accel;
 		struct {
 			uint8_t pwr_mode : 2;
 			uint8_t fs : 4;
 			uint8_t odr : 4;
+			uint8_t lpf : 3;
 		} gyro;
 	} settings;
 };

drivers/sensor/tdk/icm45686/icm45686_reg.h

@@ -10,11 +10,13 @@
 #define ZEPHYR_DRIVERS_SENSOR_ICM45686_REG_H_
 
 #include <zephyr/sys/util.h>
+#include <zephyr/sys/byteorder.h>
 
 /* Address value has a read bit */
 #define REG_SPI_READ_BIT BIT(7)
 
 /* Registers */
+/* Register Bank 0 */
 #define REG_ACCEL_DATA_X1_UI			0x00
 #define REG_ACCEL_DATA_X0_UI			0x01
 #define REG_ACCEL_DATA_Y1_UI			0x02
@@ -34,8 +36,19 @@
 #define REG_GYRO_CONFIG0			0x1C
 #define REG_DRIVE_CONFIG0			0x32
 #define REG_WHO_AM_I				0x72
+#define REG_IREG_ADDR_15_8			0x7C
+#define REG_IREG_ADDR_7_0			0x7D
+#define REG_IREG_DATA				0x7E
 #define REG_MISC2				0x7F
 
+/* User Bank IPREG_SYS1 - Gyro-related config settings */
+#define REG_IPREG_SYS1_OFFSET			0xA400
+#define REG_IPREG_SYS1_REG_172			0xAC
+
+/* User Bank IPREG_SYS2 - Accel-related config settings */
+#define REG_IPREG_SYS2_OFFSET			0xA500
+#define REG_IPREG_SYS2_REG_131			0x83
+
 /* Helper Macros for register manipulation */
 #define REG_PWR_MGMT0_ACCEL_MODE(val)			((val) & BIT_MASK(2))
 #define REG_PWR_MGMT0_GYRO_MODE(val)			(((val) & BIT_MASK(2)) << 2)
@@ -50,7 +63,13 @@
 
 #define REG_MISC2_SOFT_RST(val)				((val << 1) & BIT(1))
 
+#define REG_IPREG_SYS1_REG_172_GYRO_LPFBW_SEL(val)	(val & BIT_MASK(3))
+
+#define REG_IPREG_SYS2_REG_131_ACCEL_LPFBW_SEL(val)	(val & BIT_MASK(3))
+
 /* Misc. Defines */
 #define WHO_AM_I_ICM45686 0xE9
 
+#define REG_IREG_PREPARE_WRITE_ARRAY(base, reg, val)	{((base) >> 8) & 0xFF, reg, val}
+
 #endif /* ZEPHYR_DRIVERS_SENSOR_ICM45686_REG_H_ */

dts/bindings/sensor/invensense,icm45686.yaml

@@ -79,6 +79,22 @@ properties:
       - 3 # ICM45686_DT_ACCEL_FS_4
       - 4 # ICM45686_DT_ACCEL_FS_2
 
+  accel-lpf:
+    type: int
+    default: 0
+    description: |
+      Specify the accelerometer low pass filter cut-off frequency
+      as a fraction of the output data rate.
+      Default is power-up configuration.
+    enum:
+      - 0 # ICM45686_DT_ACCEL_LPF_BW_OFF
+      - 1 # ICM45686_DT_ACCEL_LPF_BW_1_4
+      - 2 # ICM45686_DT_ACCEL_LPF_BW_1_8
+      - 3 # ICM45686_DT_ACCEL_LPF_BW_1_16
+      - 4 # ICM45686_DT_ACCEL_LPF_BW_1_32
+      - 5 # ICM45686_DT_ACCEL_LPF_BW_1_64
+      - 6 # ICM45686_DT_ACCEL_LPF_BW_1_128
+
   gyro-pwr-mode:
     type: int
     default: 0
@@ -128,3 +144,19 @@ properties:
       - 6 # ICM45686_DT_GYRO_FS_62_5
       - 7 # ICM45686_DT_GYRO_FS_31_25
       - 8 # ICM45686_DT_GYRO_FS_15_625
+
+  gyro-lpf:
+    type: int
+    default: 0
+    description: |
+      Specify the gyro low pass filter cut-off frequency
+      as a fraction of the output data rate.
+      Default is power-up configuration.
+    enum:
+      - 0 # ICM45686_DT_GYRO_LPF_BW_OFF
+      - 1 # ICM45686_DT_GYRO_LPF_BW_1_4
+      - 2 # ICM45686_DT_GYRO_LPF_BW_1_8
+      - 3 # ICM45686_DT_GYRO_LPF_BW_1_16
+      - 4 # ICM45686_DT_GYRO_LPF_BW_1_32
+      - 5 # ICM45686_DT_GYRO_LPF_BW_1_64
+      - 6 # ICM45686_DT_GYRO_LPF_BW_1_128

include/zephyr/dt-bindings/sensor/icm45686.h

@@ -97,6 +97,33 @@
 #define ICM45686_DT_GYRO_ODR_1_5625	15 /* LP-mode only */
 /** @} */
 
+/**
+ * @defgroup ICM45686_GYRO_LPF Gyroscope Low-pass Filtering options
+ * @{
+ */
+#define ICM45686_DT_GYRO_LPF_BW_OFF	0
+#define ICM45686_DT_GYRO_LPF_BW_1_4	1
+#define ICM45686_DT_GYRO_LPF_BW_1_8	2
+#define ICM45686_DT_GYRO_LPF_BW_1_16	3
+#define ICM45686_DT_GYRO_LPF_BW_1_32	4
+#define ICM45686_DT_GYRO_LPF_BW_1_64	5
+#define ICM45686_DT_GYRO_LPF_BW_1_128	6
+/** @} */
+
+/**
+ * @defgroup ICM45686_ACCEL_LPF Accelerometer Low-pass Filtering options
+ * @{
+ */
+#define ICM45686_DT_ACCEL_LPF_BW_OFF	0
+#define ICM45686_DT_ACCEL_LPF_BW_1_4	1
+#define ICM45686_DT_ACCEL_LPF_BW_1_8	2
+#define ICM45686_DT_ACCEL_LPF_BW_1_16	3
+#define ICM45686_DT_ACCEL_LPF_BW_1_32	4
+#define ICM45686_DT_ACCEL_LPF_BW_1_64	5
+#define ICM45686_DT_ACCEL_LPF_BW_1_128	6
+/** @} */
+
+
 /** @} */
 
 #endif /* ZEPHYR_INCLUDE_DT_BINDINGS_TDK_ICM45686_H_ */