sensor: adxl345: Set FIFO to bypass mode when DRDY is enabled

In order to prevent not serving all events that would clear the
interrupt line. This patch also removes FIFO servicing through
fetch/get APIs, as this is only exposed through streaming mode.

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

Author: ubieda

drivers/sensor/adi/adxl345/adxl345.c

@@ -325,28 +325,16 @@ static int adxl345_sample_fetch(const struct device *dev,
 {
 	struct adxl345_dev_data *data = dev->data;
 	struct adxl345_sample sample;
-	uint8_t samples_count;
 	int rc;
 
-	data->sample_number = 0;
-	rc = adxl345_reg_read_byte(dev, ADXL345_FIFO_STATUS_REG, &samples_count);
+	rc = adxl345_read_sample(dev, &sample);
 	if (rc < 0) {
-		LOG_ERR("Failed to read FIFO status rc = %d\n", rc);
+		LOG_ERR("Failed to fetch sample rc=%d\n", rc);
 		return rc;
 	}
-
-	__ASSERT_NO_MSG(samples_count <= ARRAY_SIZE(data->bufx));
-
-	for (uint8_t s = 0; s < samples_count; s++) {
-		rc = adxl345_read_sample(dev, &sample);
-		if (rc < 0) {
-			LOG_ERR("Failed to fetch sample rc=%d\n", rc);
-			return rc;
-		}
-		data->bufx[s] = sample.x;
-		data->bufy[s] = sample.y;
-		data->bufz[s] = sample.z;
-	}
+	data->samples.x = sample.x;
+	data->samples.y = sample.y;
+	data->samples.z = sample.z;
 
 	return 0;
 }
@@ -357,28 +345,20 @@ static int adxl345_channel_get(const struct device *dev,
 {
 	struct adxl345_dev_data *data = dev->data;
 
-	if (data->sample_number >= ARRAY_SIZE(data->bufx)) {
-		data->sample_number = 0;
-	}
-
 	switch (chan) {
 	case SENSOR_CHAN_ACCEL_X:
-		adxl345_accel_convert(val, data->bufx[data->sample_number]);
-		data->sample_number++;
+		adxl345_accel_convert(val, data->samples.x);
 		break;
 	case SENSOR_CHAN_ACCEL_Y:
-		adxl345_accel_convert(val, data->bufy[data->sample_number]);
-		data->sample_number++;
+		adxl345_accel_convert(val, data->samples.y);
 		break;
 	case SENSOR_CHAN_ACCEL_Z:
-		adxl345_accel_convert(val, data->bufz[data->sample_number]);
-		data->sample_number++;
+		adxl345_accel_convert(val, data->samples.z);
 		break;
 	case SENSOR_CHAN_ACCEL_XYZ:
-		adxl345_accel_convert(val++, data->bufx[data->sample_number]);
-		adxl345_accel_convert(val++, data->bufy[data->sample_number]);
-		adxl345_accel_convert(val,   data->bufz[data->sample_number]);
-		data->sample_number++;
+		adxl345_accel_convert(val++, data->samples.x);
+		adxl345_accel_convert(val++, data->samples.y);
+		adxl345_accel_convert(val,   data->samples.z);
 		break;
 	default:
 		return -ENOTSUP;
@@ -444,8 +424,6 @@ static int adxl345_init(const struct device *dev)
 #endif
 	uint8_t dev_id, full_res;
 
-	data->sample_number = 0;
-
 	if (!adxl345_bus_is_ready(dev)) {
 		LOG_ERR("bus not ready");
 		return -ENODEV;
@@ -479,14 +457,14 @@ static int adxl345_init(const struct device *dev)
 		return -EIO;
 	}
 
-#ifdef CONFIG_ADXL345_TRIGGER
-	rc = adxl345_configure_fifo(dev, ADXL345_FIFO_STREAMED,
-				     ADXL345_INT2,
-				     cfg->fifo_config.fifo_samples);
+	rc = adxl345_configure_fifo(dev,
+				    IS_ENABLED(CONFIG_ADXL345_STREAM) ? ADXL345_FIFO_STREAMED :
+									ADXL345_FIFO_BYPASSED,
+				    ADXL345_INT2,
+				    cfg->fifo_config.fifo_samples);
 	if (rc) {
 		return rc;
 	}
-#endif
 
 	rc = adxl345_reg_write_byte(dev, ADXL345_POWER_CTL_REG, ADXL345_ENABLE_MEASURE_BIT);
 	if (rc < 0) {

drivers/sensor/adi/adxl345/adxl345.h

@@ -151,10 +151,11 @@ enum adxl345_op_mode {
 };
 
 struct adxl345_dev_data {
-	unsigned int sample_number;
-	int16_t bufx[ADXL345_MAX_FIFO_SIZE];
-	int16_t bufy[ADXL345_MAX_FIFO_SIZE];
-	int16_t bufz[ADXL345_MAX_FIFO_SIZE];
+	struct {
+		int16_t x;
+		int16_t y;
+		int16_t z;
+	} samples;
 	struct adxl345_fifo_config fifo_config;
 	uint8_t is_full_res;
 	uint8_t selected_range;
@@ -273,8 +274,8 @@ int adxl345_reg_write_byte(const struct device *dev, uint8_t addr, uint8_t val);
 int adxl345_reg_read_byte(const struct device *dev, uint8_t addr, uint8_t *buf);
 
 int adxl345_set_op_mode(const struct device *dev, enum adxl345_op_mode op_mode);
-#ifdef CONFIG_SENSOR_ASYNC_API
 int adxl345_read_sample(const struct device *dev, struct adxl345_sample *sample);
+#ifdef CONFIG_SENSOR_ASYNC_API
 void adxl345_submit(const struct device *dev, struct rtio_iodev_sqe *iodev_sqe);
 int adxl345_get_decoder(const struct device *dev, const struct sensor_decoder_api **decoder);
 void adxl345_accel_convert(struct sensor_value *val, int16_t sample);

drivers/sensor/adi/adxl345/adxl345_trigger.c

@@ -90,7 +90,9 @@ int adxl345_trigger_set(const struct device *dev,
 {
 	const struct adxl345_dev_config *cfg = dev->config;
 	struct adxl345_dev_data *drv_data = dev->data;
-	uint8_t int_mask, int_en, status1;
+	struct adxl345_sample sample;
+	uint8_t int_mask, int_en;
+	uint8_t samples_count;
 	int ret;
 
 	ret = gpio_pin_interrupt_configure_dt(&cfg->interrupt,
@@ -103,26 +105,45 @@ int adxl345_trigger_set(const struct device *dev,
 	case SENSOR_TRIG_DATA_READY:
 		drv_data->drdy_handler = handler;
 		drv_data->drdy_trigger = trig;
-		int_mask = ADXL345_INT_MAP_DATA_RDY_MSK;
+		/** Enabling DRDY means not using Watermark interrupt as both
+		 * are served by reading data-register: two clients can't be
+		 * served simultaneously.
+		 */
+		int_mask = ADXL345_INT_MAP_DATA_RDY_MSK |
+			   ADXL345_INT_MAP_OVERRUN_MSK |
+			   ADXL345_INT_MAP_WATERMARK_MSK;
 		break;
 	default:
 		LOG_ERR("Unsupported sensor trigger");
 		return -ENOTSUP;
 	}
 
 	if (handler) {
-		int_en = int_mask;
+		int_en = ADXL345_INT_MAP_DATA_RDY_MSK;
 	} else {
 		int_en = 0U;
 	}
 
+#ifdef CONFIG_ADXL345_STREAM
+	(void)adxl345_configure_fifo(dev, ADXL345_FIFO_BYPASSED, ADXL345_INT2, 0);
+#endif
+
+	ret = adxl345_reg_write_mask(dev, ADXL345_INT_ENABLE, int_mask, 0);
+	if (ret < 0) {
+		return ret;
+	}
+
 	ret = adxl345_reg_write_mask(dev, ADXL345_INT_MAP, int_mask, int_en);
 	if (ret < 0) {
 		return ret;
 	}
-	/* Clear status */
-	ret = adxl345_get_status(dev, &status1, NULL);
+
+	/* Clear status and read sample-set to clear interrupt flag */
+	(void)adxl345_read_sample(dev, &sample);
+
+	ret = adxl345_reg_read_byte(dev, ADXL345_FIFO_STATUS_REG, &samples_count);
 	if (ret < 0) {
+		LOG_ERR("Failed to read FIFO status rc = %d\n", ret);
 		return ret;
 	}
 
@@ -132,6 +153,11 @@ int adxl345_trigger_set(const struct device *dev,
 		return ret;
 	}
 
+	ret = adxl345_reg_write_mask(dev, ADXL345_INT_ENABLE, int_mask, int_en);
+	if (ret < 0) {
+		return ret;
+	}
+
 	return 0;
 }