WIP - Add Strings to device structure

Added the ability to query the
Manufactur, product name and serial number strings from a device.

WIP - Eats up lots of memory, next up experiment move from Device_t object to maybe top level objects.  Probably fewer than them as each hub allocates something like 7 Device objects

USBHost_t36.h

@@ -141,6 +141,7 @@ typedef union {
 } setup_t;
 
 // Device_t holds all the information about a USB device
+#define DEVICE_STRUCT_STRING_BUF_SIZE 48
 struct Device_struct {
 	Pipe_t   *control_pipe;
 	Pipe_t   *data_pipes;
@@ -159,6 +160,8 @@ struct Device_struct {
 	uint16_t idVendor;
 	uint16_t idProduct;
 	uint16_t LanguageID;
+	uint8_t	 string_buf[DEVICE_STRUCT_STRING_BUF_SIZE]; // Probably want a place to allocate fewer of these...
+	uint8_t	 iStrings[3];			// 3 indexes - vendor string, product string, serial number. 
 };
 
 // Pipe_t holes all information about each USB endpoint/pipe
@@ -248,6 +251,7 @@ protected:
 	static volatile bool enumeration_busy;
 private:
 	static void isr();
+	static void convertStringDescriptorToASCIIString(uint8_t string_index, Device_t *dev, const Transfer_t *transfer);
 	static void claim_drivers(Device_t *dev);
 	static uint32_t assign_address(void);
 	static bool queue_Transfer(Pipe_t *pipe, Transfer_t *transfer);
@@ -350,6 +354,11 @@ public:
 	operator bool() { return (device != nullptr); }
 	uint16_t idVendor() { return (device != nullptr) ? device->idVendor : 0; }
 	uint16_t idProduct() { return (device != nullptr) ? device->idProduct : 0; }
+
+	const uint8_t *manufacturer() { return (device != nullptr) ? &(device->string_buf[device->iStrings[0]]) : nullptr; }
+	const uint8_t *product() { return (device != nullptr) ? &(device->string_buf[device->iStrings[1]]) : nullptr; }
+	const uint8_t *serialNumber() { return (device != nullptr) ? &(device->string_buf[device->iStrings[2]]) : nullptr; }
+
 	// TODO: user-level functions
 	// check if device is bound/active/online
 	// query vid, pid

enumeration.cpp

@@ -201,6 +201,10 @@ void USBHost::enumeration(const Transfer_t *transfer)
 			dev->enum_state = 4;
 			return;
 		case 4: // parse Language ID
+			dev->iStrings[0] = 0;  // Set indexes into string buffer to say not there...
+			dev->iStrings[1] = 0;
+			dev->iStrings[2] = 0;
+			dev->string_buf[0] = 0;	// have trailing NULL..
 			if (enumbuf[4] < 4 || enumbuf[5] != 3) {
 				dev->enum_state = 11;
 			} else {
@@ -218,6 +222,7 @@ void USBHost::enumeration(const Transfer_t *transfer)
 			dev->enum_state = 6;
 			return;
 		case 6: // parse Manufacturer string
+			convertStringDescriptorToASCIIString(0, dev, transfer);
 			// TODO: receive the string...
 			if (enumbuf[1]) dev->enum_state = 7;
 			else if (enumbuf[2]) dev->enum_state = 9;
@@ -230,7 +235,7 @@ void USBHost::enumeration(const Transfer_t *transfer)
 			dev->enum_state = 8;
 			return;
 		case 8: // parse Product string
-			// TODO: receive the string...
+			convertStringDescriptorToASCIIString(1, dev, transfer);
 			if (enumbuf[2]) dev->enum_state = 9;
 			else dev->enum_state = 11;
 			break;
@@ -241,7 +246,7 @@ void USBHost::enumeration(const Transfer_t *transfer)
 			dev->enum_state = 10;
 			return;
 		case 10: // parse Serial Number string
-			// TODO: receive the string...
+			convertStringDescriptorToASCIIString(2, dev, transfer);
 			dev->enum_state = 11;
 			break;
 		case 11: // request first 9 bytes of config desc
@@ -286,6 +291,33 @@ void USBHost::enumeration(const Transfer_t *transfer)
 	}
 }
 
+void  USBHost::convertStringDescriptorToASCIIString(uint8_t string_index, Device_t *dev, const Transfer_t *transfer) {
+	uint8_t *buffer = (uint8_t*)transfer->buffer;
+	uint8_t buf_index = string_index? dev->iStrings[string_index]+1 : 0;
+
+	// Try to verify - The first byte should be length and the 2nd byte should be 0x3
+	if (!buffer || (buffer[1] != 0x3)) {
+		return;	// No string so can simply return
+	}
+
+	dev->iStrings[string_index] = buf_index;	// remember our starting positio
+	uint8_t count_bytes_returned = buffer[0];
+	if ((buf_index + count_bytes_returned/2) >= DEVICE_STRUCT_STRING_BUF_SIZE)
+		count_bytes_returned = (DEVICE_STRUCT_STRING_BUF_SIZE - buf_index) * 2;
+
+	// Now copy into our storage buffer. 
+	for (uint8_t i = 2; (i < count_bytes_returned) && (buf_index < (DEVICE_STRUCT_STRING_BUF_SIZE -1)); i += 2) {
+		dev->string_buf[buf_index++] = buffer[i];
+	} 
+	dev->string_buf[buf_index] = 0;	// null terminate. 
+
+	// Update other indexes to point to null character
+	while (++string_index < 3) {
+		dev->iStrings[string_index] = buf_index;	// point to trailing NULL character
+	}
+}
+
+
 void USBHost::claim_drivers(Device_t *dev)
 {
 	USBDriver *driver, *prev=NULL;

examples/Mouse/Mouse.ino

@@ -49,6 +49,12 @@ void loop()
         Serial.printf("*** Device %s %x:%x - connected ***\n", driver_names[i], drivers[i]->idVendor(), drivers[i]->idProduct());
         driver_active[i] = true;
 
+        const uint8_t *psz = drivers[i]->manufacturer();
+        if (psz && *psz) Serial.printf("  manufacturer: %s\n", psz);
+        psz = drivers[i]->product();
+        if (psz && *psz) Serial.printf("  product: %s\n", psz);
+        psz = drivers[i]->serialNumber();
+        if (psz && *psz) Serial.printf("  Serial: %s\n", psz);
       }
     }
   }