[PUSB] Fixed check for available endpoints

The check for available slot in PluggableUSB is done on the endpoint
and not on the number of plugged modules.

The modulesCount field is no longer useful and it has been removed.

cores/arduino/PluggableUSB.cpp

@@ -23,58 +23,56 @@
 #if defined(USBCON)	
 #ifdef PLUGGABLE_USB_ENABLED
 
-#define MAX_MODULES	6
+// TODO: set correct value for different CPUs
+#define MAX_EP 6
 
 extern uint8_t _initEndpoints[];
 
-//PUSBCallbacks cbs[MAX_MODULES];
-
 PluggableUSB_ PluggableUSB;
 
 int PluggableUSB_::getInterface(uint8_t* interfaceNum)
 {
 	int ret = 0;
-	PUSBListNode* node = rootNode;
-	for (uint8_t i=0; i<modulesCount; i++) {
+	PUSBListNode* node;
+	for (node = rootNode; node; node = node->next) {
 		ret = node->getInterface(interfaceNum);
-		node = node->next;
 	}
 	return ret;
 }
 
 int PluggableUSB_::getDescriptor(int8_t t)
 {
-	int ret = 0;
-	PUSBListNode* node = rootNode;
-	for (uint8_t i=0; i<modulesCount && ret == 0; i++) {
-		ret = node->getDescriptor(t);
-		node = node->next;
+	PUSBListNode* node;
+	for (node = rootNode; node; node = node->next) {
+		int ret = node->getDescriptor(t);
+		if (ret)
+			return ret;
 	}
-	return ret;
+	return 0;
 }
 
 bool PluggableUSB_::setup(USBSetup& setup, uint8_t j)
 {
-	bool ret = false;
-	PUSBListNode* node = rootNode;
-	for (uint8_t i=0; i<modulesCount && ret == false; i++) {
-		ret = node->setup(setup, j);
-		node = node->next;
+	PUSBListNode* node;
+	for (node = rootNode; node; node = node->next) {
+		if (node->setup(setup, j)) {
+			return true;
+		}
 	}
-	return ret;
+	return false;
 }
 
 bool PluggableUSB_::plug(PUSBListNode *node)
 {
-	if (modulesCount >= MAX_MODULES) {
+	if ((lastEp + node->numEndpoints) >= MAX_EP) {
 		return false;
 	}
 
-	if (modulesCount == 0) {
+	if (!rootNode) {
 		rootNode = node;
 	} else {
 		PUSBListNode *current = rootNode;
-		while(current->next != NULL) {
+		while (current->next) {
 			current = current->next;
 		}
 		current->next = node;
@@ -83,18 +81,17 @@ bool PluggableUSB_::plug(PUSBListNode *node)
 	node->pluggedInterface = lastIf;
 	node->pluggedEndpoint = lastEp;
 	lastIf += node->numInterfaces;
-	for (uint8_t i=0; i<node->numEndpoints; i++) {
+	for (uint8_t i = 0; i < node->numEndpoints; i++) {
 		_initEndpoints[lastEp] = node->endpointType[i];
 		lastEp++;
 	}
-	modulesCount++;
 	return true;
 	// restart USB layer???
 }
 
 PluggableUSB_::PluggableUSB_() : lastIf(CDC_ACM_INTERFACE + CDC_INTERFACE_COUNT),
                                  lastEp(CDC_FIRST_ENDPOINT + CDC_ENPOINT_COUNT),
-                                 modulesCount(0), rootNode(NULL)
+                                 rootNode(NULL)
 {
 	// Empty
 }

cores/arduino/PluggableUSB.h

@@ -63,7 +63,6 @@ public:
 private:
   uint8_t lastIf;
   uint8_t lastEp;
-  uint8_t modulesCount;
   PUSBListNode* rootNode;
 };