keep track of pin status using g_pinStatus array and act accordingly

This commit adds 80 bytes to RAM usage and some overhead in normal operations.

Author: facchinm

hardware/arduino/sam/cores/arduino/Arduino.h

@@ -155,6 +155,16 @@ typedef enum _ETCChannel
 #define PIN_ATTR_PWM           (1UL<<3)
 #define PIN_ATTR_TIMER         (1UL<<4)
 
+#define PIN_STATUS_DIGITAL_INPUT_PULLUP  (0x01)
+#define PIN_STATUS_DIGITAL_INPUT         (0x02)
+#define PIN_STATUS_DIGITAL_OUTPUT        (0x03)
+#define PIN_STATUS_ANALOG                (0x04)
+#define PIN_STATUS_PWM                   (0x05)
+#define PIN_STATUS_TIMER                 (0x06)
+#define PIN_STATUS_SERIAL                (0x07)
+#define PIN_STATUS_DW_LOW                (0x10)
+#define PIN_STATUS_DW_HIGH               (0x11)
+
 /* Types used for the tables below */
 typedef struct _PinDescription
 {
@@ -170,6 +180,8 @@ typedef struct _PinDescription
   ETCChannel ulTCChannel ;
 } PinDescription ;
 
+extern uint8_t g_pinStatus[];
+
 /* Pins table to be instanciated into variant.cpp */
 extern const PinDescription g_APinDescription[] ;
 

hardware/arduino/sam/cores/arduino/wiring_analog.c

@@ -153,6 +153,7 @@ uint32_t analogRead(uint32_t ulPin)
 				if ( latestSelectedChannel != (uint32_t)-1 && ulChannel != latestSelectedChannel)
 					adc_disable_channel( ADC, latestSelectedChannel );
 				latestSelectedChannel = ulChannel;
+				g_pinStatus[ulPin] = (g_pinStatus[ulPin] & 0xF0) | PIN_STATUS_ANALOG;
 			}
 
 			// Start the ADC
@@ -189,13 +190,9 @@ static void TC_SetCMR_ChannelB(Tc *tc, uint32_t chan, uint32_t v)
 }
 
 static uint8_t PWMEnabled = 0;
-static uint8_t pinEnabled[PINS_COUNT];
 static uint8_t TCChanEnabled[] = {0, 0, 0, 0, 0, 0, 0, 0, 0};
 
 void analogOutputInit(void) {
-	uint8_t i;
-	for (i=0; i<PINS_COUNT; i++)
-		pinEnabled[i] = 0;
 }
 
 // Right now, PWM output only works on the pins with
@@ -263,7 +260,7 @@ void analogWrite(uint32_t ulPin, uint32_t ulValue) {
 		}
 
 		uint32_t chan = g_APinDescription[ulPin].ulPWMChannel;
-		if (!pinEnabled[ulPin]) {
+		if ((g_pinStatus[ulPin] & 0xF) != PIN_STATUS_PWM) {
 			// Setup PWM for this pin
 			PIO_Configure(g_APinDescription[ulPin].pPort,
 					g_APinDescription[ulPin].ulPinType,
@@ -273,7 +270,7 @@ void analogWrite(uint32_t ulPin, uint32_t ulValue) {
 			PWMC_SetPeriod(PWM_INTERFACE, chan, PWM_MAX_DUTY_CYCLE);
 			PWMC_SetDutyCycle(PWM_INTERFACE, chan, ulValue);
 			PWMC_EnableChannel(PWM_INTERFACE, chan);
-			pinEnabled[ulPin] = 1;
+			g_pinStatus[ulPin] = (g_pinStatus[ulPin] & 0xF0) | PIN_STATUS_PWM;
 		}
 
 		PWMC_SetDutyCycle(PWM_INTERFACE, chan, ulValue);
@@ -328,12 +325,12 @@ void analogWrite(uint32_t ulPin, uint32_t ulValue) {
 				TC_SetCMR_ChannelB(chTC, chNo, TC_CMR_BCPB_CLEAR | TC_CMR_BCPC_SET);
 			}
 		}
-		if (!pinEnabled[ulPin]) {
+		if ((g_pinStatus[ulPin] & 0xF) != PIN_STATUS_PWM) {
 			PIO_Configure(g_APinDescription[ulPin].pPort,
 					g_APinDescription[ulPin].ulPinType,
 					g_APinDescription[ulPin].ulPin,
 					g_APinDescription[ulPin].ulPinConfiguration);
-			pinEnabled[ulPin] = 1;
+			g_pinStatus[ulPin] = (g_pinStatus[ulPin] & 0xF0) | PIN_STATUS_PWM;
 		}
 		if (!TCChanEnabled[interfaceID]) {
 			TC_Start(chTC, chNo);

hardware/arduino/sam/cores/arduino/wiring_digital.c

@@ -29,12 +29,19 @@ extern void pinMode( uint32_t ulPin, uint32_t ulMode )
         return ;
     }
 
-#if defined __SAM3X8E__ || defined __SAM3X8H__
-  if(g_APinDescription[ulPin].ulPinType != NO_ADC && adc_get_channel_status(ADC, g_APinDescription[ulPin].ulADCChannelNumber))
+  if ((g_pinStatus[ulPin] & 0xF) == PIN_STATUS_ANALOG)
     {
       adc_disable_channel( ADC, g_APinDescription[ulPin].ulADCChannelNumber);
     }
-#endif
+
+  if ((g_pinStatus[ulPin] & 0xF) < PIN_STATUS_DIGITAL_OUTPUT && g_pinStatus[ulPin] != 0)
+    {
+      // return if already configured in the right way
+      if (((g_pinStatus[ulPin] & 0xF) == PIN_STATUS_DIGITAL_INPUT && ulMode == INPUT) ||
+          ((g_pinStatus[ulPin] & 0xF) == PIN_STATUS_DIGITAL_INPUT_PULLUP && ulMode == INPUT_PULLUP) ||
+          ((g_pinStatus[ulPin] & 0xF) == PIN_STATUS_DIGITAL_OUTPUT && ulMode == OUTPUT))
+      return;
+    }
 
 	switch ( ulMode )
     {
@@ -46,6 +53,7 @@ extern void pinMode( uint32_t ulPin, uint32_t ulMode )
             	PIO_INPUT,
             	g_APinDescription[ulPin].ulPin,
             	0 ) ;
+            g_pinStatus[ulPin] = (g_pinStatus[ulPin] & 0xF0) | PIN_STATUS_DIGITAL_INPUT;
         break ;
 
         case INPUT_PULLUP:
@@ -56,15 +64,18 @@ extern void pinMode( uint32_t ulPin, uint32_t ulMode )
             	PIO_INPUT,
             	g_APinDescription[ulPin].ulPin,
             	PIO_PULLUP ) ;
+            g_pinStatus[ulPin] = (g_pinStatus[ulPin] & 0xF0) | PIN_STATUS_DIGITAL_INPUT_PULLUP;
         break ;
 
         case OUTPUT:
             PIO_Configure(
             	g_APinDescription[ulPin].pPort,
-            	PIO_OUTPUT_0,
+              g_pinStatus[ulPin] = ((g_pinStatus[ulPin] & 0xF0) >> 4 ? PIO_OUTPUT_1 : PIO_OUTPUT_0),
             	g_APinDescription[ulPin].ulPin,
             	g_APinDescription[ulPin].ulPinConfiguration ) ;
 
+            g_pinStatus[ulPin] = (g_pinStatus[ulPin] & 0xF0) | PIN_STATUS_DIGITAL_OUTPUT;
+
             /* if all pins are output, disable PIO Controller clocking, reduce power consumption */
             if ( g_APinDescription[ulPin].pPort->PIO_OSR == 0xffffffff )
             {
@@ -85,6 +96,12 @@ extern void digitalWrite( uint32_t ulPin, uint32_t ulVal )
     return ;
   }
 
+  if ((g_pinStatus[ulPin] & 0xF) == PIN_STATUS_PWM) {
+    pinMode(ulPin, OUTPUT);
+  }
+
+  g_pinStatus[ulPin] = (g_pinStatus[ulPin] & 0x0F) | (ulVal << 4) ;
+
   if ( PIO_GetOutputDataStatus( g_APinDescription[ulPin].pPort, g_APinDescription[ulPin].ulPin ) == 0 )
   {
     PIO_PullUp( g_APinDescription[ulPin].pPort, g_APinDescription[ulPin].ulPin, ulVal ) ;
@@ -97,6 +114,14 @@ extern void digitalWrite( uint32_t ulPin, uint32_t ulVal )
 
 extern int digitalRead( uint32_t ulPin )
 {
+  if ((g_pinStatus[ulPin] & 0xF) == PIN_STATUS_DIGITAL_OUTPUT) {
+    return (g_pinStatus[ulPin] & 0xF0) >> 4;
+  }
+
+  if ((g_pinStatus[ulPin] & 0xF) == PIN_STATUS_ANALOG) {
+    pinMode(ulPin, INPUT);
+  }
+
 	if ( g_APinDescription[ulPin].ulPinType == PIO_NOT_A_PIN )
     {
         return LOW ;

hardware/arduino/sam/variants/arduino_due_x/variant.cpp

@@ -291,6 +291,9 @@ extern const PinDescription g_APinDescription[]=
   { NULL, 0, 0, PIO_NOT_A_PIN, PIO_DEFAULT, 0, NO_ADC, NO_ADC, NOT_ON_PWM, NOT_ON_TIMER }
 } ;
 
+
+uint8_t g_pinStatus[PINS_COUNT] = {0};
+
 #ifdef __cplusplus
 }
 #endif