STM32F3xx - Disable GPIO configuration for ADC internal channels

Author: bcostm

hal/targets/hal/TARGET_STM/TARGET_STM32F3/analogin_api.c

@@ -1,5 +1,5 @@
 /* mbed Microcontroller Library
- * Copyright (c) 2015, STMicroelectronics
+ * Copyright (c) 2016, STMicroelectronics
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -62,8 +62,10 @@ void analogin_init(analogin_t *obj, PinName pin)
     MBED_ASSERT(function != (uint32_t)NC);
     obj->channel = STM_PIN_CHANNEL(function);
 
-    // Configure GPIO
-    pinmap_pinout(pin, PinMap_ADC);
+    // Configure GPIO excepted for internal channels (Temperature, Vref, Vbat)
+    if ((obj->channel != 16) && (obj->channel != 17) && (obj->channel != 18)) {
+        pinmap_pinout(pin, PinMap_ADC);
+    }
 
     // Save pin number for the read function
     obj->pin = pin;