use plugged modules name to create iSerial field

To solve the re-enumeration problem on Win, two different approaches where tested:
- creating a S/N based on the descriptor length (collisions still possible, less overhead)
- craft a S/N string from the pluggable modules properties (no collision, no difference between different HID submodules)

A call has been added getShortName and it MUST be implemented by any library based on PluggableUSB. No effect on PluggableHID-based libraries.

Author: facchinm

hardware/arduino/avr/cores/arduino/PluggableUSB.cpp

@@ -23,7 +23,7 @@
 #if defined(USBCON)	
 #ifdef PLUGGABLE_USB_ENABLED
 
-#define MAX_MODULES	6
+#define MAX_MODULES	3
 
 static u8 lastIf = CDC_ACM_INTERFACE + CDC_INTERFACE_COUNT;
 static u8 lastEp = CDC_FIRST_ENDPOINT + CDC_ENPOINT_COUNT;
@@ -35,12 +35,14 @@ static u8 modules_count = 0;
 
 static PUSBListNode* rootNode = NULL;
 
+char _iSerialNum[2*MAX_MODULES] = {0};
+
 int PUSB_GetInterface(u8* interfaceNum)
 {
 	int ret = 0;
 	PUSBListNode* node = rootNode;
 	for (u8 i=0; i<modules_count; i++) {
-		ret = node->cb->getInterface(interfaceNum);
+		ret += node->cb->getInterface(interfaceNum);
 		node = node->next;
 	}
 	return ret;
@@ -57,6 +59,18 @@ int PUSB_GetDescriptor(int8_t t)
 	return ret;
 }
 
+char* PUSB_GetShortName()
+{
+	char* ret = 0;
+	PUSBListNode* node = rootNode;
+	for (u8 i=0; i<modules_count; i++) {
+		ret = node->cb->getShortName();
+		memcpy(&_iSerialNum[i*2], ret, 2);
+		node = node->next;
+	}
+	return _iSerialNum;
+}
+
 bool PUSB_Setup(USBSetup& setup, u8 j)
 {
 	bool ret = false;

hardware/arduino/avr/cores/arduino/PluggableUSB.h

@@ -30,6 +30,7 @@ typedef struct __attribute__((packed))
   bool (*setup)(USBSetup& setup, u8 i);
   int (*getInterface)(u8* interfaceNum);
   int (*getDescriptor)(int8_t t);
+  char* (*getShortName)();
   int8_t numEndpoints;
   int8_t numInterfaces;
   uint8_t *endpointType;
@@ -54,6 +55,8 @@ int PUSB_GetInterface(u8* interfaceNum);
 
 int PUSB_GetDescriptor(int8_t t);
 
+char* PUSB_GetShortName();
+
 bool PUSB_Setup(USBSetup& setup, u8 i);
 
 void PUSB_Begin();

hardware/arduino/avr/cores/arduino/USBCore.cpp

@@ -82,8 +82,6 @@ volatile u8 _usbConfiguration = 0;
 volatile u8 _usbCurrentStatus = 0; // meaning of bits see usb_20.pdf, Figure 9-4. Information Returned by a GetStatus() Request to a Device
 volatile u8 _usbSuspendState = 0; // copy of UDINT to check SUSPI and WAKEUPI bits
 
-static int iSerial = 0;
-
 static inline void WaitIN(void)
 {
 	while (!(UEINTX & (1<<TXINI)))
@@ -458,10 +456,10 @@ int SendInterfaces()
 {
 	u8 interfaces = 0;
 
-	iSerial = CDC_GetInterface(&interfaces);
+	CDC_GetInterface(&interfaces);
 
 #ifdef PLUGGABLE_USB_ENABLED
-	iSerial += PUSB_GetInterface(&interfaces);
+	PUSB_GetInterface(&interfaces);
 #endif
 
 	return interfaces;
@@ -522,9 +520,10 @@ bool SendDescriptor(USBSetup& setup)
 			return USB_SendStringDescriptor(STRING_MANUFACTURER, strlen(USB_MANUFACTURER));
 		}
 		else if (setup.wValueL == ISERIAL) {
-			char StringNum[4];
-			itoa(iSerial, StringNum, 10);
-			return USB_SendStringDescriptorRAM((u8*)StringNum, strlen(StringNum));
+#ifdef PLUGGABLE_USB_ENABLED
+			char* name = PUSB_GetShortName();
+			return USB_SendStringDescriptorRAM((uint8_t*)name, strlen(name));
+#endif
 		}
 		else
 			return false;

hardware/arduino/avr/libraries/HID/HID.cpp

@@ -79,6 +79,12 @@ int HID_GetDescriptor(int8_t t)
 	}
 }
 
+char* HID_GetShortName()
+{
+	static char* name = "HI";
+	return name;
+}
+
 void HID_::AppendDescriptor(HIDDescriptorListNode *node)
 {
 	if (modules_count == 0) {
@@ -149,6 +155,7 @@ HID_::HID_(void)
 		.setup = &HID_Setup,
 		.getInterface = &HID_GetInterface,
 		.getDescriptor = &HID_GetDescriptor,
+		.getShortName = &HID_GetShortName,
 		.numEndpoints = 1,
 		.numInterfaces = 1,
 		.endpointType = endpointType,

hardware/arduino/sam/cores/arduino/USB/PluggableUSB.cpp

@@ -35,12 +35,14 @@ static uint8_t modules_count = 0;
 
 static PUSBListNode* rootNode = NULL;
 
+char _iSerialNum[2*MAX_MODULES] = {0};
+
 int PUSB_GetInterface(uint8_t* interfaceNum)
 {
 	int ret = 0;
 	PUSBListNode* node = rootNode;
 	for (uint8_t i=0; i<modules_count; i++) {
-		ret = node->cb->getInterface(interfaceNum);
+		ret += node->cb->getInterface(interfaceNum);
 		node = node->next;
 	}
 	return ret;
@@ -68,6 +70,18 @@ bool PUSB_Setup(USBSetup& setup, uint8_t j)
 	return ret;
 }
 
+char* PUSB_GetShortName()
+{
+	char* ret = 0;
+	PUSBListNode* node = rootNode;
+	for (uint8_t i=0; i<modules_count; i++) {
+		ret = node->cb->getShortName();
+		memcpy(&_iSerialNum[i*2], ret, 2);
+		node = node->next;
+	}
+	return _iSerialNum;
+}
+
 int8_t PUSB_AddFunction(PUSBListNode *node, uint8_t* interface)
 {
 	if (modules_count >= MAX_MODULES) {

hardware/arduino/sam/cores/arduino/USB/PluggableUSB.h

@@ -30,6 +30,7 @@ typedef struct __attribute__((packed))
   bool (*setup)(USBSetup& setup, uint8_t i);
   int (*getInterface)(uint8_t* interfaceNum);
   int (*getDescriptor)(int8_t t);
+  char* (*getShortName)();
   int8_t numEndpoints;
   int8_t numInterfaces;
   uint32_t *endpointType;
@@ -56,6 +57,8 @@ int PUSB_GetDescriptor(int8_t t);
 
 bool PUSB_Setup(USBSetup& setup, uint8_t i);
 
+char* PUSB_GetShortName();
+
 void PUSB_Begin();
 
 #endif

hardware/arduino/sam/cores/arduino/USB/USBCore.cpp

@@ -96,10 +96,10 @@ const uint8_t STRING_MANUFACTURER[12] = USB_MANUFACTURER;
 
 //	DEVICE DESCRIPTOR
 const DeviceDescriptor USB_DeviceDescriptor =
-	D_DEVICE(0x00,0x00,0x00,64,USB_VID,USB_PID,0x100,IMANUFACTURER,IPRODUCT,0,1);
+	D_DEVICE(0x00,0x00,0x00,64,USB_VID,USB_PID,0x100,IMANUFACTURER,IPRODUCT,ISERIAL,1);
 
 const DeviceDescriptor USB_DeviceDescriptorA =
-	D_DEVICE(0xEF,0x02,0x01,64,USB_VID,USB_PID,0x100,IMANUFACTURER,IPRODUCT,0,1);
+	D_DEVICE(0xEF,0x02,0x01,64,USB_VID,USB_PID,0x100,IMANUFACTURER,IPRODUCT,ISERIAL,1);
 
 const DeviceDescriptor USB_DeviceQualifier =
 	D_QUALIFIER(0x00,0x00,0x00,64,1);
@@ -429,6 +429,12 @@ static bool USBD_SendDescriptor(USBSetup& setup)
 		else if (setup.wValueL == IMANUFACTURER) {
 			return USB_SendStringDescriptor(STRING_MANUFACTURER, setup.wLength);
 		}
+		else if (setup.wValueL == ISERIAL) {
+#ifdef PLUGGABLE_USB_ENABLED
+			char* name = PUSB_GetShortName();
+			return USB_SendStringDescriptor((uint8_t*)name, setup.wLength);
+#endif
+		}
 		else {
 			return false;
 		}

hardware/arduino/sam/cores/arduino/USB/USBDesc.h

@@ -44,5 +44,6 @@
 
 #define IMANUFACTURER	1
 #define IPRODUCT		2
+#define ISERIAL			3
 
 #endif /* __USBDESC_H__ */

hardware/arduino/sam/libraries/HID/HID.cpp

@@ -77,6 +77,12 @@ int HID_GetDescriptor(int8_t t)
 	}
 }
 
+char* HID_GetShortName()
+{
+	static char* name = "HI";
+	return name;
+}
+
 void HID_::AppendDescriptor(HIDDescriptorListNode *node)
 {
 	if (modules_count == 0) {
@@ -152,6 +158,7 @@ HID_::HID_(void)
 		.setup = &HID_Setup,
 		.getInterface = &HID_GetInterface,
 		.getDescriptor = &HID_GetDescriptor,
+		.getShortName = &HID_GetShortName,
 		.numEndpoints = 1,
 		.numInterfaces = 1,
 		.endpointType = endpointType,