Adxl345 refac and FIFO

drivers/sensor/adi/adxl345/adxl345.c

@@ -279,11 +279,9 @@ static int adxl345_attr_set(const struct device *dev,
 }
 
 int adxl345_read_sample(const struct device *dev,
-			       struct adxl345_sample *sample)
+			   struct adxl345_sample *sample)
 {
-	int16_t raw_x, raw_y, raw_z;
-	struct adxl345_dev_data *data = dev->data;
-	uint8_t axis_data[6];
+	uint8_t axis_data[ADXL345_FIFO_SAMPLE_SIZE];
 	int rc;
 
 	rc = adxl345_reg_read(dev, ADXL345_REG_DATA_XYZ_REGS,
@@ -293,74 +291,127 @@ int adxl345_read_sample(const struct device *dev,
 		return rc;
 	}
 
-	raw_x = axis_data[0] | (axis_data[1] << 8);
-	raw_y = axis_data[2] | (axis_data[3] << 8);
-	raw_z = axis_data[4] | (axis_data[5] << 8);
+	sample->x = axis_data[0] | axis_data[1] << 8;
+	sample->y = axis_data[2] | axis_data[3] << 8;
+	sample->z = axis_data[4] | axis_data[5] << 8;
 
-	sample->x = raw_x;
-	sample->y = raw_y;
-	sample->z = raw_z;
+#ifdef CONFIG_ADXL345_TRIGGER
+	struct adxl345_dev_data *data = dev->data;
 
+	sample->is_full_res = data->is_full_res; /* needed for decoder */
 	sample->selected_range = data->selected_range;
-	sample->is_full_res = data->is_full_res;
+#endif
 
-	return 0;
+	return rc;
 }
 
-void adxl345_accel_convert(struct sensor_value *val, int16_t sample)
+/**
+ * adxl345_accel_convert - The fallback conversion of raw measurements.
+ * @out: Converted value for output, containing the initialized fractional.
+ * @sample: Input raw measurement.
+ * When working without decoder, neither TRIGGER, nor STREAM is enabled,
+ * this small converter is used. It assumes full scale resolution and 8g.
+ */
+void adxl345_accel_convert(struct sensor_value *out, int16_t sample)
 {
-	if (sample & BIT(9)) {
-		sample |= ADXL345_COMPLEMENT;
+	/* full resolution enabled w/ 8g */
+	if (sample & BIT(11)) {
+		sample |= ADXL345_COMPLEMENT_MASK(12);
 	}
-
-	val->val1 = ((sample * SENSOR_G) / 32) / 1000000;
-	val->val2 = ((sample * SENSOR_G) / 32) % 1000000;
+	out->val1 = ((sample * SENSOR_G) / 32) / 1000000;
+	out->val2 = ((sample * SENSOR_G) / 32) % 1000000;
 }
 
 static int adxl345_sample_fetch(const struct device *dev,
 				enum sensor_channel chan)
 {
 	struct adxl345_dev_data *data = dev->data;
-	struct adxl345_sample sample;
+	uint8_t count;
 	int rc;
 
-	rc = adxl345_read_sample(dev, &sample);
-	if (rc < 0) {
-		LOG_ERR("Failed to fetch sample rc=%d\n", rc);
-		return rc;
+	count = 1;
+
+	/* FIFO BYPASSED is the only mode not using a FIFO buffer */
+	if (data->fifo_config.fifo_mode != ADXL345_FIFO_BYPASSED) {
+		count = adxl345_get_fifo_entries(dev);
+		if (count < 0) {
+			return -EIO;
+		}
+	}
+
+	__ASSERT_NO_MSG(count <= ARRAY_SIZE(data->sample));
+
+	for (uint8_t s = 0; s < count; s++) {
+		rc = adxl345_read_sample(dev, &data->sample[s]);
+		if (rc < 0) {
+			LOG_ERR("Failed to fetch sample rc=%d\n", rc);
+			return rc;
+		}
+
+#ifdef CONFIG_ADXL345_STREAM
+		data->sample[s].is_fifo = 0;
+#endif
 	}
-	data->samples.x = sample.x;
-	data->samples.y = sample.y;
-	data->samples.z = sample.z;
+
+	/* new sample available, reset book-keeping */
+	data->sample_idx = 0;
+	data->sample_number = count;
 
 	return 0;
 }
 
+/**
+ * adxl345_channel_get - Read a single element of one or three axis.
+ * @dev: The sensor device.
+ * @chan: The axis channel, can be x, y, z or xyz.
+ * @val: The resulting value after conversion of the raw axis data. Val can be
+ * a single value or an array of three values, where the index correspondes to
+ * x, y, z axis entries.
+ */
 static int adxl345_channel_get(const struct device *dev,
 			       enum sensor_channel chan,
 			       struct sensor_value *val)
 {
 	struct adxl345_dev_data *data = dev->data;
+	int idx;
+
+	if (data->sample_number <= 0) { /* empty */
+		val->val1 = 0;
+		val->val2 = 0;
+		if (chan == SENSOR_CHAN_ACCEL_XYZ) {
+			val[1].val1 = 0;
+			val[1].val2 = 0;
+			val[2].val1 = 0;
+			val[2].val2 = 0;
+		}
+		return -ENOTSUP;
+	}
+
+	data->sample_idx = data->sample_idx % data->sample_number;
+	idx = data->sample_idx;
 
 	switch (chan) {
 	case SENSOR_CHAN_ACCEL_X:
-		adxl345_accel_convert(val, data->samples.x);
+		adxl345_accel_convert(val, data->sample[idx].x);
 		break;
 	case SENSOR_CHAN_ACCEL_Y:
-		adxl345_accel_convert(val, data->samples.y);
+		adxl345_accel_convert(val, data->sample[idx].y);
 		break;
 	case SENSOR_CHAN_ACCEL_Z:
-		adxl345_accel_convert(val, data->samples.z);
+		adxl345_accel_convert(val, data->sample[idx].z);
 		break;
 	case SENSOR_CHAN_ACCEL_XYZ:
-		adxl345_accel_convert(val++, data->samples.x);
-		adxl345_accel_convert(val++, data->samples.y);
-		adxl345_accel_convert(val,   data->samples.z);
+		adxl345_accel_convert(val++, data->sample[idx].x);
+		adxl345_accel_convert(val++, data->sample[idx].y);
+		adxl345_accel_convert(val,   data->sample[idx].z);
+
 		break;
 	default:
 		return -ENOTSUP;
 	}
 
+	data->sample_idx++;
+
 	return 0;
 }
 

drivers/sensor/adi/adxl345/adxl345.h

@@ -171,12 +171,22 @@ struct adxl345_fifo_config {
 	uint8_t fifo_samples;
 };
 
+struct adxl345_sample {
+#ifdef CONFIG_ADXL345_STREAM
+	uint8_t is_fifo: 1;
+	uint8_t res: 7;
+#endif /* CONFIG_ADXL345_STREAM */
+	enum adxl345_range selected_range;
+	bool is_full_res;
+	int16_t x;
+	int16_t y;
+	int16_t z;
+} __attribute__((__packed__));
+
 struct adxl345_dev_data {
-	struct {
-		int16_t x;
-		int16_t y;
-		int16_t z;
-	} samples;
+	struct adxl345_sample sample[ADXL345_MAX_FIFO_SIZE];
+	uint8_t sample_number; /* number of samples to read from sensor */
+	uint8_t sample_idx; /* index counting up sample_number entries */
 	struct adxl345_fifo_config fifo_config;
 	bool is_full_res;
 	enum adxl345_range selected_range;
@@ -228,18 +238,6 @@ struct adxl345_fifo_data {
 	uint64_t timestamp;
 } __attribute__((__packed__));
 
-struct adxl345_sample {
-#ifdef CONFIG_ADXL345_STREAM
-	uint8_t is_fifo: 1;
-	uint8_t res: 7;
-#endif /* CONFIG_ADXL345_STREAM */
-	uint8_t selected_range;
-	bool is_full_res;
-	int16_t x;
-	int16_t y;
-	int16_t z;
-};
-
 union adxl345_bus {
 #if DT_ANY_INST_ON_BUS_STATUS_OKAY(i2c)
 	struct i2c_dt_spec i2c;