sensor: bme680: simplify conversion logic

Read less data from the sensor and use standard zephyr functions for
extracting integers from byte arrays.

Signed-off-by: Jordan Yates <[email protected]>

Author: JordanYates

drivers/sensor/bosch/bme680/bme680.c

@@ -23,6 +23,13 @@
 
 LOG_MODULE_REGISTER(bme680, CONFIG_SENSOR_LOG_LEVEL);
 
+struct bme_data_regs {
+	uint8_t pressure[3];
+	uint8_t temperature[3];
+	uint8_t humidity[2];
+	uint8_t padding[3];
+	uint8_t gas[2];
+} __packed;
 
 #if BME680_BUS_SPI
 static inline bool bme680_is_on_spi(const struct device *dev)
@@ -41,7 +48,7 @@ static inline int bme680_bus_check(const struct device *dev)
 }
 
 static inline int bme680_reg_read(const struct device *dev,
-				  uint8_t start, uint8_t *buf, int size)
+				  uint8_t start, void *buf, int size)
 {
 	const struct bme680_config *config = dev->config;
 
@@ -209,12 +216,11 @@ static int bme680_sample_fetch(const struct device *dev,
 			       enum sensor_channel chan)
 {
 	struct bme680_data *data = dev->data;
-	uint8_t buff[BME680_LEN_FIELD] = { 0 };
+	struct bme_data_regs data_regs;
 	uint8_t gas_range;
 	uint32_t adc_temp, adc_press;
 	uint16_t adc_hum, adc_gas_res;
 	uint8_t status;
-	int size = BME680_LEN_FIELD;
 	int cnt = 0;
 	int ret;
 
@@ -235,35 +241,29 @@ static int bme680_sample_fetch(const struct device *dev,
 			return -EAGAIN;
 		}
 		k_sleep(K_MSEC(1));
-		ret = bme680_reg_read(dev, BME680_REG_FIELD0, &status, 1);
+		ret = bme680_reg_read(dev, BME680_REG_MEAS_STATUS, &status, 1);
 		if (ret < 0) {
 			return ret;
 		}
 	} while (!(status & BME680_MSK_NEW_DATA));
 	LOG_DBG("New data after %d ms", cnt);
 
-	ret = bme680_reg_read(dev, BME680_REG_FIELD0, buff, size);
+	ret = bme680_reg_read(dev, BME680_REG_FIELD0, &data_regs, sizeof(data_regs));
 	if (ret < 0) {
 		return ret;
 	}
 
-	data->new_data = true;
-	data->heatr_stab = buff[14] & BME680_MSK_HEATR_STAB;
-
-	adc_press = (uint32_t)(((uint32_t)buff[2] << 12) | ((uint32_t)buff[3] << 4)
-			    | ((uint32_t)buff[4] >> 4));
-	adc_temp = (uint32_t)(((uint32_t)buff[5] << 12) | ((uint32_t)buff[6] << 4)
-			   | ((uint32_t)buff[7] >> 4));
-	adc_hum = (uint16_t)(((uint32_t)buff[8] << 8) | (uint32_t)buff[9]);
-	adc_gas_res = (uint16_t)((uint32_t)buff[13] << 2 | (((uint32_t)buff[14]) >> 6));
-	gas_range = buff[14] & BME680_MSK_GAS_RANGE;
-
-	if (data->new_data) {
-		bme680_calc_temp(data, adc_temp);
-		bme680_calc_press(data, adc_press);
-		bme680_calc_humidity(data, adc_hum);
-		bme680_calc_gas_resistance(data, gas_range, adc_gas_res);
-	}
+	adc_press = sys_get_be24(data_regs.pressure) >> 4;
+	adc_temp = sys_get_be24(data_regs.temperature) >> 4;
+	adc_hum = sys_get_be16(data_regs.humidity);
+	adc_gas_res = sys_get_be16(data_regs.gas) >> 6;
+	data->heatr_stab = data_regs.gas[1] & BME680_MSK_HEATR_STAB;
+	gas_range = data_regs.gas[1] & BME680_MSK_GAS_RANGE;
+
+	bme680_calc_temp(data, adc_temp);
+	bme680_calc_press(data, adc_press);
+	bme680_calc_humidity(data, adc_hum);
+	bme680_calc_gas_resistance(data, gas_range, adc_gas_res);
 	return 0;
 }
 

drivers/sensor/bosch/bme680/bme680.h

@@ -57,24 +57,24 @@ struct bme680_config {
 
 #define BME680_CHIP_ID                  0x61
 
-#define BME680_LEN_FIELD                15
 #define BME680_LEN_COEFF_ALL            42
 #define BME680_LEN_COEFF1               23
 #define BME680_LEN_COEFF2               14
 #define BME680_LEN_COEFF3               5
 
 #define BME680_REG_COEFF3               0x00
-#define BME680_REG_FIELD0               0x1d
+#define BME680_REG_MEAS_STATUS          0x1D
+#define BME680_REG_FIELD0               0x1F
 #define BME680_REG_IDAC_HEAT0           0x50
 #define BME680_REG_RES_HEAT0            0x5A
 #define BME680_REG_GAS_WAIT0            0x64
 #define BME680_REG_SHD_HEATR_DUR        0x6E
 #define BME680_REG_CTRL_GAS_0           0x70
 #define BME680_REG_CTRL_GAS_1           0x71
 #define BME680_REG_CTRL_HUM             0x72
+#define BME680_REG_STATUS               0x73
 #define BME680_REG_CTRL_MEAS            0x74
 #define BME680_REG_CONFIG               0x75
-#define BME680_REG_STATUS               0x73
 #define BME680_REG_UNIQUE_ID            0x83
 #define BME680_REG_COEFF1               0x8a
 #define BME680_REG_COEFF2               0xe1
@@ -204,7 +204,6 @@ struct bme680_data {
 	uint32_t calc_gas_resistance;
 
 	/* Additional information */
-	uint8_t new_data;
 	uint8_t heatr_stab;
 
 	/* Carryover between temperature and pressure/humidity compensation. */