drivers: icm42688: pin9 function

PIN9 of an ICM42688 can be configured as an interrupt output, external
clock input or frame sync output. Pin function can now be set via a sensor
attribute.

Signed-off-by: Yau-ming Leung <[email protected]>

Author: ymleung314

drivers/sensor/tdk/icm42688/icm42688.c

@@ -9,6 +9,7 @@
 #define DT_DRV_COMPAT invensense_icm42688
 
 #include <zephyr/drivers/sensor.h>
+#include <zephyr/drivers/sensor/icm42688.h>
 #include <zephyr/drivers/spi.h>
 #include <zephyr/sys/byteorder.h>
 
@@ -162,6 +163,23 @@ static int icm42688_attr_set(const struct device *dev, enum sensor_channel chan,
 				return -EINVAL;
 			}
 			new_config.batch_ticks = val->val1;
+		} else if ((enum sensor_attribute_icm42688)attr ==
+			   SENSOR_ATTR_ICM42688_PIN9_FUNCTION) {
+			if (val->val1 != ICM42688_PIN9_FUNCTION_INT2 &&
+			    val->val1 != ICM42688_PIN9_FUNCTION_FSYNC &&
+			    val->val1 != ICM42688_PIN9_FUNCTION_CLKIN) {
+				LOG_ERR("Unknown pin function");
+				return -EINVAL;
+			}
+
+			/* TODO: Allow this if FSYNC is configurable later. */
+			if (val->val1 == ICM42688_PIN9_FUNCTION_FSYNC) {
+				LOG_ERR("FSYNC is disabled, PIN9_FUNCTION should not be set to "
+					"FSYNC");
+				return -ENOTSUP;
+			}
+
+			new_config.pin9_function = val->val1;
 		} else {
 			LOG_ERR("Unsupported attribute");
 			res = -EINVAL;
@@ -219,6 +237,10 @@ static int icm42688_attr_get(const struct device *dev, enum sensor_channel chan,
 		if (attr == SENSOR_ATTR_BATCH_DURATION) {
 			val->val1 = cfg->batch_ticks;
 			val->val2 = 0;
+		} else if ((enum sensor_attribute_icm42688)attr ==
+			   SENSOR_ATTR_ICM42688_PIN9_FUNCTION) {
+			val->val1 = cfg->pin9_function;
+			val->val2 = 0;
 		} else {
 			LOG_ERR("Unsupported attribute");
 			res = -EINVAL;
@@ -313,7 +335,8 @@ void icm42688_unlock(const struct device *dev)
 		.fifo_hires = false,					\
 		.interrupt1_drdy = false,				\
 		.interrupt1_fifo_ths = false,				\
-		.interrupt1_fifo_full = false				\
+		.interrupt1_fifo_full = false,				\
+		.pin9_function = ICM42688_PIN9_FUNCTION_INT2		\
 	}
 
 #define ICM42688_DEFINE_DATA(inst)                                                                 \

drivers/sensor/tdk/icm42688/icm42688.h

@@ -308,6 +308,8 @@ struct icm42688_cfg {
 	bool interrupt1_drdy;
 	bool interrupt1_fifo_ths;
 	bool interrupt1_fifo_full;
+
+	uint8_t pin9_function;
 };
 
 struct icm42688_trigger_entry {

drivers/sensor/tdk/icm42688/icm42688_common.c

@@ -7,6 +7,7 @@
  */
 
 #include <zephyr/drivers/sensor.h>
+#include <zephyr/drivers/sensor/icm42688.h>
 #include <zephyr/drivers/spi.h>
 #include <zephyr/sys/byteorder.h>
 #include "icm42688.h"
@@ -148,6 +149,47 @@ int icm42688_configure(const struct device *dev, struct icm42688_cfg *cfg)
 
 	/* TODO maybe do the next few steps intelligently by checking current config */
 
+	/* Select register bank 1 */
+	res = icm42688_spi_single_write(&dev_cfg->spi, REG_BANK_SEL, BIT_BANK1);
+	if (res != 0) {
+		LOG_ERR("Error selecting register bank 1");
+		return -EINVAL;
+	}
+
+	k_busy_wait(50);
+
+	/* Set pin 9 function */
+	uint8_t intf_config5 = FIELD_PREP(MASK_PIN9_FUNCTION, cfg->pin9_function);
+
+	LOG_DBG("INTF_CONFIG5 (0x%lx) 0x%x", FIELD_GET(REG_ADDRESS_MASK, REG_INTF_CONFIG5),
+		intf_config5);
+	res = icm42688_spi_single_write(&dev_cfg->spi, REG_INTF_CONFIG5, intf_config5);
+	if (res != 0) {
+		LOG_ERR("Error writing INTF_CONFIG5");
+		return -EINVAL;
+	}
+
+	/* Select register bank 0 */
+	res = icm42688_spi_single_write(&dev_cfg->spi, REG_BANK_SEL, BIT_BANK0);
+	if (res != 0) {
+		LOG_ERR("Error selecting register bank 0");
+		return -EINVAL;
+	}
+
+	k_busy_wait(50);
+
+	bool is_pin9_clkin = cfg->pin9_function == ICM42688_PIN9_FUNCTION_CLKIN;
+	uint8_t intf_config1 = 0x91 | FIELD_PREP(BIT_RTC_MODE, is_pin9_clkin);
+
+	LOG_DBG("INTF_CONFIG1 (0x%x) 0x%x", REG_INTF_CONFIG1, intf_config1);
+	res = icm42688_spi_single_write(&dev_cfg->spi, REG_INTF_CONFIG1, intf_config1);
+	if (res != 0) {
+		LOG_ERR("Error writing INTF_CONFIG1");
+		return -EINVAL;
+	}
+
+	k_busy_wait(250);
+
 	/* Power management to set gyro/accel modes */
 	uint8_t pwr_mgmt0 = FIELD_PREP(MASK_GYRO_MODE, cfg->gyro_pwr_mode) |
 			    FIELD_PREP(MASK_ACCEL_MODE, cfg->accel_pwr_mode) |

drivers/sensor/tdk/icm42688/icm42688_reg.h

@@ -276,6 +276,9 @@
 #define BIT_INT_TDEASSERT_DISABLE BIT(5)
 #define BIT_INT_ASYNC_RESET	  BIT(4)
 
+/* Bank1 REG_INTF_CONFIG5 */
+#define MASK_PIN9_FUNCTION GENMASK(2, 1)
+
 /* misc. defines */
 #define WHO_AM_I_ICM42688     0x47
 #define MIN_ACCEL_SENS_SHIFT  11

include/zephyr/drivers/sensor/icm42688.h

@@ -0,0 +1,32 @@
+/*
+ * Copyright The Zephyr Project Contributors
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef ZEPHYR_INCLUDE_DRIVERS_SENSOR_ICM42688_H_
+#define ZEPHYR_INCLUDE_DRIVERS_SENSOR_ICM42688_H_
+
+#include <zephyr/drivers/sensor.h>
+
+/**
+ * @file
+ * @brief Extended public API for ICM42688
+ *
+ * Pin function configuration via attributes under the current sensor driver abstraction.
+ */
+
+#define ICM42688_PIN9_FUNCTION_INT2  0
+#define ICM42688_PIN9_FUNCTION_FSYNC 1
+#define ICM42688_PIN9_FUNCTION_CLKIN 2
+
+/**
+ * @brief Extended sensor attributes for ICM42688
+ *
+ * Attributes for setting pin function.
+ */
+enum sensor_attribute_icm42688 {
+	SENSOR_ATTR_ICM42688_PIN9_FUNCTION = SENSOR_ATTR_PRIV_START
+};
+
+#endif /* ZEPHYR_INCLUDE_DRIVERS_SENSOR_ICM42688_H_ */