WIP: initial support for fixed-point data for sensors

Documentation/components/drivers/special/sensors/sensors_uorb.rst

@@ -48,11 +48,60 @@ sensor events are sent to the ring buffer in the upper layer.
    :width: 800px
    :align: center
 
-Problems to solve
-=================
+Sensor data type
+================
+
+The framework supports two types of sensor data:
+
+#. ``float`` if ``CONFIG_SENSORS_USE_FLOAT=y``, not recommended for
+   targets without FPU.
+
+#. ``b16_t`` if ``CONFIG_SENSORS_USE_B16=y``, recommended for targets without
+   FPU.
+
+Currently all sensors support ``float``, support for ``b16_t`` is work-in-progress.
+
+To create generic drivers that support both data types, you should use the dedicated
+sensor data type:
+
+.. code:: C
+
+   /* Data type for sensors */
+
+   #ifdef CONFIG_SENSORS_USE_B16
+   typedef b16_t sensor_data_t;
+   #else
+   typedef float sensor_data_t;
+   #endif
+
+Mathematical operations on this type should only be performed using dedicated
+macros:
+
+- ``sensor_data_ftof(f1)`` - convert float to sensor data number.
+  Should be used only for compile-time constants.
+
+- ``sensor_data_itof(i)`` - convert int to sensor data number.
+
+- ``sensor_data_inv(i)`` - invert int and convert to sensor data number
+
+- ``sensor_data_add(f1, f2)`` - add two sensor data numbers
+
+- ``sensor_data_sub(f1, f2)`` - subtract two sensor data numbers
+
+- ``sensor_data_subi(f1, i)`` - subtract int from sensor data number
+
+- ``sensor_data_mul(f1, f2)`` - multiplicate two sensor data numbers
+
+- ``sensor_data_muli(f1, i)`` - multiplicate sensor data with int
+
+- ``sensor_data_div(f1, f2)`` - divide two sensor data numbers
+
+- ``sensor_data_divi(f1, i)`` - divide sensor data with int
+
+- ``sensor_data_abs(f1)`` - get absolute value for sensor data number
+
+- ``sensor_data_sqrt(f1)`` - get sqrt for sensro data number
 
-The current implementation uses the ``float`` type which may make it difficult
-to use on platforms without FPU support.
 
 **Code**
 ========
@@ -313,9 +362,9 @@ being ``sensor_device_info_s``.
   struct sensor_device_info_s
   {
     uint32_t      version;
-    float         power;
-    float         max_range;
-    float         resolution;
+    sensor_data_t power;
+    sensor_data_t max_range;
+    sensor_data_t resolution;
     int32_t       min_delay;
     int32_t       max_delay;
     uint32_t      fifo_reserved_event_count;

drivers/sensors/Kconfig

@@ -17,6 +17,24 @@ config USENSOR
 	---help---
 		Allow application to register user sensor by /dev/usensor.
 
+choice
+	prompt "Sensor framework data type"
+	default SENSORS_USE_FLOAT
+
+config SENSORS_USE_FLOAT
+	bool "Use float as data type for sensors"
+	---help---
+		Use float as data type for sensors.
+		This option is recommended if for targets with FPU support.
+
+config SENSORS_USE_B16
+	bool "Use b16_t as data type for sensors"
+	---help---
+		Use b16_t (fixed-point type) as data type for sensors.
+		This option is recommended if for targets without FPU support.
+
+endchoice # Sensor framework data type
+
 config SENSORS_RPMSG
 	bool "Sensor RPMSG Support"
 	default n

drivers/sensors/adxl362_uorb.c

@@ -106,7 +106,7 @@ struct adxl362_sensor_s
   struct sensor_lowerhalf_s  lower;
   FAR struct spi_dev_s      *spi;
   int                        devno;
-  float                      scale;
+  sensor_data_t              scale;
 #ifdef CONFIG_SENSORS_ADXL362_POLL
   bool                       enabled;
   uint32_t                   interval;
@@ -482,10 +482,12 @@ static int adxl362_fetch(FAR struct sensor_lowerhalf_s *lower,
   adxl362_getregs(priv, ADXL362_XDATA_L, (FAR uint8_t *)data, 8);
 
   accel.timestamp   = sensor_get_timestamp();
-  accel.x           = (float)adxl362_data(&data[0]) * priv->scale;
-  accel.y           = (float)adxl362_data(&data[2]) * priv->scale;
-  accel.z           = (float)adxl362_data(&data[4]) * priv->scale;
-  accel.temperature = (float)adxl362_data(&data[6]) * ADXL362_TEMP_SCALE;
+
+  accel.x           = sensor_data_muli(priv->scale, adxl362_data(&data[0]));
+  accel.y           = sensor_data_muli(priv->scale, adxl362_data(&data[2]));
+  accel.z           = sensor_data_muli(priv->scale, adxl362_data(&data[4]));
+  accel.temperature = sensor_data_muli(
+    sensor_data_ftof(ADXL362_TEMP_SCALE), adxl362_data(&data[6]));
 
   memcpy(buffer, &accel, sizeof(accel));
 
@@ -539,11 +541,14 @@ static int adxl362_thread(int argc, FAR char **argv)
           adxl362_getregs(priv, ADXL362_XDATA_L, (FAR uint8_t *)data, 8);
 
           accel.timestamp   = sensor_get_timestamp();
-          accel.x           = (float)adxl362_data(&data[0]) * priv->scale;
-          accel.y           = (float)adxl362_data(&data[2]) * priv->scale;
-          accel.z           = (float)adxl362_data(&data[4]) * priv->scale;
-          accel.temperature =
-            (float)adxl362_data(&data[6]) * ADXL362_TEMP_SCALE;
+          accel.x           = sensor_data_muli(priv->scale,
+                                               adxl362_data(&data[0]));
+          accel.y           = sensor_data_muli(priv->scale,
+                                               adxl362_data(&data[2]));
+          accel.z           = sensor_data_muli(priv->scale,
+                                               adxl362_data(&data[4]));
+          accel.temperature = sensor_data_muli(
+            sensor_data_ftof(ADXL362_TEMP_SCALE), adxl362_data(&data[6]));
 
           priv->lower.push_event(priv->lower.priv, &accel, sizeof(accel));
         }
@@ -602,7 +607,7 @@ int adxl362_register(int devno, FAR struct spi_dev_s *spi)
   priv->lower.ops     = &g_adxl362_accel_ops;
   priv->lower.type    = SENSOR_TYPE_ACCELEROMETER;
   priv->lower.nbuffer = 1;
-  priv->scale         = (CONSTANTS_ONE_G / 1000.0f);
+  priv->scale         = sensor_data_ftof(CONSTANTS_ONE_G / 1000.0f);
   priv->devno         = devno;
 #ifdef CONFIG_SENSORS_ADXL362_POLL
   priv->enabled       = false;

drivers/sensors/adxl372_uorb.c

@@ -53,7 +53,7 @@ struct adxl372_sensor_s
 {
   struct sensor_lowerhalf_s  lower;
   FAR struct spi_dev_s      *spi;
-  float                      scale;
+  sensor_data_t              scale;
   int                        devno;
 #ifdef CONFIG_SENSORS_ADXL372_POLL
   bool                       enabled;
@@ -447,9 +447,9 @@ static int adxl372_fetch(FAR struct sensor_lowerhalf_s *lower,
   adxl372_getregs(priv, ADXL372_XDATA_H, (FAR uint8_t *)data, 6);
 
   accel.timestamp   = sensor_get_timestamp();
-  accel.x           = (float)adxl372_data(&data[0]) * priv->scale;
-  accel.y           = (float)adxl372_data(&data[2]) * priv->scale;
-  accel.z           = (float)adxl372_data(&data[4]) * priv->scale;
+  accel.x           = sensor_data_muli(priv->scale, adxl372_data(&data[0]));
+  accel.y           = sensor_data_muli(priv->scale, adxl372_data(&data[2]));
+  accel.z           = sensor_data_muli(priv->scale, adxl372_data(&data[4]));
   accel.temperature = 0;
 
   memcpy(buffer, &accel, sizeof(accel));
@@ -504,9 +504,12 @@ static int adxl372_thread(int argc, FAR char **argv)
           adxl372_getregs(priv, ADXL372_XDATA_H, (FAR uint8_t *)data, 6);
 
           accel.timestamp   = sensor_get_timestamp();
-          accel.x           = (float)adxl372_data(&data[0]) * priv->scale;
-          accel.y           = (float)adxl372_data(&data[2]) * priv->scale;
-          accel.z           = (float)adxl372_data(&data[4]) * priv->scale;
+          accel.x           = sensor_data_muli(priv->scale,
+                                               adxl372_data(&data[0]));
+          accel.y           = sensor_data_muli(priv->scale,
+                                               adxl372_data(&data[2]));
+          accel.z           = sensor_data_muli(priv->scale,
+                                               adxl372_data(&data[4]));
           accel.temperature = 0;
 
           priv->lower.push_event(priv->lower.priv, &accel, sizeof(accel));
@@ -566,7 +569,7 @@ int adxl372_register_uorb(int devno, FAR struct spi_dev_s *spi)
   priv->lower.ops     = &g_adxl372_accel_ops;
   priv->lower.type    = SENSOR_TYPE_ACCELEROMETER;
   priv->lower.nbuffer = 1;
-  priv->scale         = (CONSTANTS_ONE_G / 10.0f);
+  priv->scale         = sensor_data_ftof(CONSTANTS_ONE_G / 10.0f);
   priv->devno         = devno;
 #ifdef CONFIG_SENSORS_ADXL372_POLL
   priv->enabled       = false;

drivers/sensors/bh1749nuc_uorb.c

@@ -64,10 +64,10 @@ struct bh1749nuc_sensor_dev_s
 {
   struct bh1749nuc_sensor_s priv[BH1749NUC_MAX_IDX];
   struct bh1749nuc_dev_s    dev;
-  float                     scale_r;
-  float                     scale_g;
-  float                     scale_b;
-  float                     scale_ir;
+  sensor_data_t             scale_r;
+  sensor_data_t             scale_g;
+  sensor_data_t             scale_b;
+  sensor_data_t             scale_ir;
   mutex_t                   lock;
 #ifdef CONFIG_SENSORS_BH1749NUC_POLL
   sem_t                     run;
@@ -231,11 +231,11 @@ static int bh1749nuc_fetch(FAR struct sensor_lowerhalf_s *lower,
 
       rgb_data.timestamp = now;
       tmp = bh1749nuc_read16(dev, BH1749NUC_RED_DATA_LSB);
-      rgb_data.r = (tmp * priv->dev->scale_r);
+      rgb_data.r = sensor_data_muli(priv->dev->scale_r, tmp);
       tmp = bh1749nuc_read16(dev, BH1749NUC_GREEN_DATA_LSB);
-      rgb_data.g = (tmp * priv->dev->scale_g);
+      rgb_data.g = sensor_data_muli(priv->dev->scale_g, tmp);
       tmp = bh1749nuc_read16(dev, BH1749NUC_BLUE_DATA_LSB);
-      rgb_data.b = (tmp * priv->dev->scale_b);
+      rgb_data.b = sensor_data_muli(priv->dev->scale_b, tmp);
 
       memcpy(buffer, &rgb_data, sizeof(rgb_data));
       ret = sizeof(rgb_data);
@@ -250,7 +250,7 @@ static int bh1749nuc_fetch(FAR struct sensor_lowerhalf_s *lower,
 
       ir_data.timestamp = now;
       tmp = bh1749nuc_read16(dev, BH1749NUC_IR_DATA_LSB);
-      ir_data.ir = (tmp * priv->dev->scale_ir);
+      ir_data.ir = sensor_data_muli(priv->dev->scale_ir, tmp);
 
       memcpy(buffer, &ir_data, sizeof(ir_data));
       ret = sizeof(ir_data);
@@ -361,11 +361,11 @@ static int bh1749nuc_thread(int argc, FAR char **argv)
         {
           rgb_data.timestamp = now;
           tmp = bh1749nuc_read16(&dev->dev, BH1749NUC_RED_DATA_LSB);
-          rgb_data.r = (tmp * dev->scale_r);
+          rgb_data.r = sensor_data_muli(dev->scale_r, tmp);
           tmp = bh1749nuc_read16(&dev->dev, BH1749NUC_GREEN_DATA_LSB);
-          rgb_data.g = (tmp * dev->scale_g);
+          rgb_data.g = sensor_data_muli(dev->scale_g, tmp);
           tmp = bh1749nuc_read16(&dev->dev, BH1749NUC_BLUE_DATA_LSB);
-          rgb_data.b = (tmp * dev->scale_b);
+          rgb_data.b = sensor_data_muli(dev->scale_b, tmp);
 
           rgb->lower.push_event(rgb->lower.priv,
                                 &rgb_data, sizeof(rgb_data));
@@ -375,7 +375,7 @@ static int bh1749nuc_thread(int argc, FAR char **argv)
         {
           ir_data.timestamp = now;
           tmp = bh1749nuc_read16(&dev->dev, BH1749NUC_IR_DATA_LSB);
-          ir_data.ir = (tmp * dev->scale_ir);
+          ir_data.ir = sensor_data_muli(dev->scale_ir, tmp);
 
           ir->lower.push_event(ir->lower.priv,
                                &ir_data, sizeof(ir_data));
@@ -459,10 +459,10 @@ int bh1749nuc_register_uorb(int devno, FAR struct bh1749nuc_config_s *config)
 
   /* Return data in lux unit for RGB and IR */
 
-  dev->scale_r  = (20.0f / 71.0f) * (1e-6 / 1.46e-7);
-  dev->scale_g  = (20.0f / 99.0f) * (1e-6 / 1.46e-7);
-  dev->scale_b  = (20.0f / 70.0f) * (1e-6 / 1.46e-7);
-  dev->scale_ir = (20.0f / 25.0f) * (1e-6 / 1.46e-7);
+  dev->scale_r  = sensor_data_ftof((20.0f / 71.0f) * (1e-6 / 1.46e-7));
+  dev->scale_g  = sensor_data_ftof((20.0f / 99.0f) * (1e-6 / 1.46e-7));
+  dev->scale_b  = sensor_data_ftof((20.0f / 70.0f) * (1e-6 / 1.46e-7));
+  dev->scale_ir = sensor_data_ftof((20.0f / 25.0f) * (1e-6 / 1.46e-7));
 
   /*  Register sensor */
 

drivers/sensors/bme680_uorb.c

@@ -49,6 +49,12 @@
  * Pre-processor Definitions
  ****************************************************************************/
 
+/* Only float data type supported now */
+
+#ifdef CONFIG_SENSORS_USE_B16
+#  error fixed-point data type not supported yet
+#endif
+
 #define BME680_ADDR 0x76 /* I2C Slave Address */
 #define BME680_FREQ CONFIG_BME680_I2C_FREQUENCY
 #define BME680_DEVID 0x61

drivers/sensors/bme688_uorb.c

@@ -49,6 +49,12 @@
  * Pre-processor Definitions
  ****************************************************************************/
 
+/* Only float data type supported now */
+
+#ifdef CONFIG_SENSORS_USE_B16
+#  error fixed-point data type not supported yet
+#endif
+
 #define BME688_ADDR                0x76 /* I2C Slave Address */
 #define BME688_FREQ                CONFIG_BME688_I2C_FREQUENCY
 #define BME688_DEVID               0x61

drivers/sensors/bmi088_uorb.c

@@ -36,6 +36,12 @@
  * Pre-processor Definitions
  ****************************************************************************/
 
+/* Only float data type supported now */
+
+#ifdef CONFIG_SENSORS_USE_B16
+#  error fixed-point data type not supported yet
+#endif
+
 #define BMI088_DEFAULT_INTERVAL 10000  /* Default conversion interval. */
 
 /****************************************************************************

drivers/sensors/bmi160_uorb.c

@@ -36,6 +36,12 @@
  * Pre-processor Definitions
  ****************************************************************************/
 
+/* Only float data type supported now */
+
+#ifdef CONFIG_SENSORS_USE_B16
+#  error fixed-point data type not supported yet
+#endif
+
 #define BMI160_DEFAULT_INTERVAL 10000  /* Default conversion interval. */
 
 /****************************************************************************

drivers/sensors/bmi270_uorb.c

@@ -49,6 +49,12 @@
  * Pre-processor Definitions
  ****************************************************************************/
 
+/* Only float data type supported now */
+
+#ifdef CONFIG_SENSORS_USE_B16
+#  error fixed-point data type not supported yet
+#endif
+
 #define CONSTANTS_ONE_G 9.8f
 
 /****************************************************************************

drivers/sensors/bmm150_uorb.c

@@ -43,6 +43,12 @@
  * Pre-processor Definitions
  ****************************************************************************/
 
+/* Only float data type supported now */
+
+#ifdef CONFIG_SENSORS_USE_B16
+#  error fixed-point data type not supported yet
+#endif
+
 #define BMM150_CHIPID_VAL        0x32
 
 #define BMM150_CHIPID            0x40

drivers/sensors/bmp180_base.c

@@ -293,7 +293,7 @@ void bmp180_read_press_temp(FAR struct bmp180_dev_s *priv)
  ****************************************************************************/
 
 int bmp180_getpressure(FAR struct bmp180_dev_s *priv,
-                       FAR float *temperature)
+                       FAR int *temperature)
 {
   int32_t x1;
   int32_t x2;
@@ -338,7 +338,9 @@ int bmp180_getpressure(FAR struct bmp180_dev_s *priv,
   sninfo("Compensated temperature = %" PRId32 "\n", temp);
 
   if (temperature != NULL)
+    {
       *temperature = temp;
+    }
 
   /* Calculate true pressure */
 

drivers/sensors/bmp180_base.h

@@ -132,6 +132,6 @@ int bmp180_checkid(FAR struct bmp180_dev_s *priv);
 void bmp180_updatecaldata(FAR struct bmp180_dev_s *priv);
 void bmp180_read_press_temp(FAR struct bmp180_dev_s *priv);
 int bmp180_getpressure(FAR struct bmp180_dev_s *priv,
-                       FAR float *temperature);
+                       FAR int *temperature);
 
 #endif /* CONFIG_I2C && CONFIG_SENSORS_BMP180 */