feat: export adc/dac get channel functions

Functions now return -1 instead of 0 which was a valid value.
Fixes #1669

Signed-off-by: Frederic Pillon <[email protected]>

Author: fpistm

cores/arduino/stm32/analog.h

@@ -49,6 +49,13 @@ extern "C" {
 #endif
 
 /* Exported functions ------------------------------------------------------- */
+#if defined(HAL_ADC_MODULE_ENABLED) && !defined(HAL_ADC_MODULE_ONLY)
+uint32_t get_adc_channel(PinName pin, uint32_t *bank);
+uint32_t get_adc_internal_channel(PinName pin);
+#endif
+#if defined(HAL_DAC_MODULE_ENABLED) && !defined(HAL_DAC_MODULE_ONLY)
+uint32_t get_dac_channel(PinName pin);
+#endif
 void dac_write_value(PinName pin, uint32_t value, uint8_t do_init);
 void dac_stop(PinName pin);
 uint16_t adc_read_value(PinName pin, uint32_t resolution);

libraries/SrcWrapper/src/stm32/analog.cpp

@@ -101,11 +101,17 @@ static PinName g_current_pin = NC;
 #define ADC_REGULAR_RANK_1  1
 #endif
 
-/* Private Functions */
-static uint32_t get_adc_channel(PinName pin, uint32_t *bank)
+/* Exported Functions */
+/**
+  * @brief  Return ADC HAL channel linked to a PinName
+  * @param  pin: PinName
+  * @param  bank: pointer to get ADC channel bank if required
+  * @retval HAL channel. return -1 if pin has no ADC
+  */
+uint32_t get_adc_channel(PinName pin, uint32_t *bank)
 {
   uint32_t function = pinmap_function(pin, PinMap_ADC);
-  uint32_t channel = 0;
+  uint32_t channel = -1;
   switch (STM_PIN_CHANNEL(function)) {
 #ifdef ADC_CHANNEL_0
     case 0:
@@ -218,7 +224,7 @@ static uint32_t get_adc_channel(PinName pin, uint32_t *bank)
 #endif
 #endif
     default:
-      channel = 0;
+      channel = -1;
       break;
   }
 #ifdef ADC_CHANNELS_BANK_B
@@ -233,9 +239,16 @@ static uint32_t get_adc_channel(PinName pin, uint32_t *bank)
   return channel;
 }
 
-static uint32_t get_adc_internal_channel(PinName pin)
+/**
+  * @brief  Return ADC HAL internal channel linked to a PinName
+  * @param  pin: specific PinName's for ADC internal. Value can be:
+  *         PADC_TEMP, PADC_TEMP_ADC5, PADC_VREF, PADC_VBAT
+  *         Note that not all of these values ​​may be available for all series.
+  * @retval HAL internal channel. return -1 if pin has no ADC internal
+  */
+uint32_t get_adc_internal_channel(PinName pin)
 {
-  uint32_t channel = 0;
+  uint32_t channel = -1;
   switch (pin) {
 #if defined(ADC_CHANNEL_TEMPSENSOR)
     case PADC_TEMP:
@@ -263,18 +276,23 @@ static uint32_t get_adc_internal_channel(PinName pin)
       break;
 #endif
     default:
-      channel = 0;
+      channel = -1;
       break;
   }
   return channel;
 }
 #endif /* HAL_ADC_MODULE_ENABLED && !HAL_ADC_MODULE_ONLY */
 
 #if defined(HAL_DAC_MODULE_ENABLED) && !defined(HAL_DAC_MODULE_ONLY)
-static uint32_t get_dac_channel(PinName pin)
+/**
+  * @brief  Return DAC HAL channel linked to a PinName
+  * @param  pin: specific PinName's for ADC internal. Value can be:
+  * @retval HAL channel. return -1 if pin has no dac
+  */
+uint32_t get_dac_channel(PinName pin)
 {
   uint32_t function = pinmap_function(pin, PinMap_DAC);
-  uint32_t channel = 0;
+  uint32_t channel = -1;
   switch (STM_PIN_CHANNEL(function)) {
 #ifdef DAC_CHANNEL_0
     case 0:
@@ -290,7 +308,7 @@ static uint32_t get_dac_channel(PinName pin)
       break;
 #endif
     default:
-      channel = 0;
+      channel = -1;
       break;
   }
   return channel;