[sam] fixing due variant issue and preparing work on analog

hardware/sam/cores/sam/Arduino.h

@@ -78,7 +78,8 @@ typedef void (*voidFuncPtr)( void ) ;
 /* Definitions and types for pins */
 typedef enum _EAnalogChannel
 {
-  ADC0,
+  NONE=-1,
+  ADC0=0,
   ADC1,
   ADC2,
   ADC3,
@@ -119,6 +120,7 @@ typedef struct _PinDescription
   EAnalogChannel ulAnalogChannel ;
 } PinDescription ;
 
+/* Pins table to be instanciated into variant.cpp */
 extern const PinDescription g_APinDescription[] ;
 
 #ifdef __cplusplus

hardware/sam/cores/sam/wiring_analog.c.disabled

@@ -31,17 +31,14 @@
 #endif
 
 
-uint8_t analog_reference = DEFAULT;
+eAnalogReference analog_reference = AR_DEFAULT ;
 
-void analogReference(uint8_t mode)
+void analogReference( eAnalogReference ulMode )
 {
-	// can't actually set the register here because the default setting
-	// will connect AVCC and the AREF pin, which would cause a short if
-	// there's something connected to AREF.
-	analog_reference = mode;
+	analog_reference = ulMode ;
 }
 
-int analogRead(uint8_t pin)
+uint32_t analogRead( uint32_t ulPin )
 {
 	uint8_t low, high;
 
@@ -94,7 +91,7 @@ int analogRead(uint8_t pin)
 // hardware support.  These are defined in the appropriate
 // pins_*.c file.  For the rest of the pins, we default
 // to digital output.
-void analogWrite(uint8_t pin, int val)
+void analogWrite( uint32_t ulPin, uint32_t ulValue )
 {
 	// We need to make sure the PWM output is enabled for those pins
 	// that support it, as we turn it off when digitally reading or

hardware/sam/cores/sam/wiring_analog.h

@@ -8,19 +8,35 @@
 #endif
 
 /*
- * \brief
+ * \brief SAM3 products have only one reference for ADC
  */
-extern void analogReference( uint8_t mode ) ;
+typedef enum _eAnalogReference
+{
+  AR_DEFAULT,
+} eAnalogReference ;
 
 /*
- * \brief
+ * \brief Configures the reference voltage used for analog input (i.e. the value used as the top of the input range).
+ * This function is kept only for compatibility with existing AVR based API.
+ *
+ * \param ulMmode Should be set to AR_DEFAULT.
  */
-extern void analogWrite( uint8_t, int ) ;
+extern void analogReference( eAnalogReference ulMode ) ;
 
 /*
- * \brief
+ * \brief Writes an analog value (PWM wave) to a pin.
+ *
+ * \param ulPin
+ * \param ulValue
  */
-extern int analogRead( uint8_t ) ;
+extern void analogWrite( uint32_t ulPin, uint32_t ulValue ) ;
+
+/*
+ * \brief Reads the value from the specified analog pin.
+ *
+ * \param ulValue
+ */
+extern uint32_t analogRead( uint32_t ulPin ) ;
 
 
 #ifdef __cplusplus