Clean up if no analog pin is defined

Signed-off-by: Frederic Pillon <frederic.pillon@st.com>

Author: fpistm

cores/arduino/pins_arduino.h

@@ -51,12 +51,9 @@ enum {
 };
 
 // Arduino analog pins
-#ifndef NUM_ANALOG_INPUTS
-#define NUM_ANALOG_INPUTS 0
-#endif
-#ifndef NUM_ANALOG_FIRST
-#define NUM_ANALOG_FIRST NUM_DIGITAL_PINS
-#endif
+// If NUM_ANALOG_INPUTS is not defined there is no analog pins defined.
+// Anyway ADC internal channels are always avaialable.
+#if defined(NUM_ANALOG_INPUTS) && (NUM_ANALOG_INPUTS>0)
 
 // Analog pins must be contiguous to be able to loop on each value
 #define MAX_ANALOG_INPUTS 24
@@ -161,6 +158,11 @@ static const uint8_t A22 = PIN_A22;
 #define PIN_A23      (PIN_A22 + 1)
 static const uint8_t A23 = PIN_A23;
 #endif
+#else
+#ifndef NUM_ANALOG_INPUTS
+#define NUM_ANALOG_INPUTS 0
+#endif
+#endif /* NUM_ANALOG_INPUTS */
 
 // Default for Arduino connector compatibility
 // SPI Definitions
@@ -238,6 +240,7 @@ uint32_t pinNametoDigitalPin(PinName p);
 // Used by analogRead api to have A0 == 0
 #define analogInputToDigitalPin(p)  (((uint32_t)p < NUM_ANALOG_INPUTS) ? (p+A0) : p)
 #else
+// No analog pin defined
 #define analogInputToDigitalPin(p)  (NUM_DIGITAL_PINS)
 #endif
 // Convert an analog pin number Axx to a PinName PX_n