Add experimental interface

teensy4/usb.c

 	uint32_t callback_param;
 };*/
 
+#ifdef EXPERIMENTAL_INTERFACE
+uint8_t experimental_buffer[1152] __attribute__ ((section(".dmabuffers"), aligned(64)));
+#endif
+
 endpoint_t endpoint_queue_head[(NUM_ENDPOINTS+1)*2] __attribute__ ((used, aligned(4096)));
 
 transfer_t endpoint0_transfer_data __attribute__ ((used, aligned(32)));
 		#if defined(AUDIO_INTERFACE)
 		usb_audio_configure();
 		#endif
+		#if defined(EXPERIMENTAL_INTERFACE)
+		endpoint_queue_head[2].unused1 = (uint32_t)experimental_buffer;
+		#endif
 		endpoint0_receive(NULL, 0, 0);
 		return;
 	  case 0x0880: // GET_CONFIGURATION

teensy4/usb_desc.c

 #define MULTITOUCH_INTERFACE_DESC_SIZE	0
 #endif
 
-#define CONFIG_DESC_SIZE		MULTITOUCH_INTERFACE_DESC_POS+MULTITOUCH_INTERFACE_DESC_SIZE
+#define EXPERIMENTAL_INTERFACE_DESC_POS	MULTITOUCH_INTERFACE_DESC_POS+MULTITOUCH_INTERFACE_DESC_SIZE
+#ifdef  EXPERIMENTAL_INTERFACE
+#define EXPERIMENTAL_INTERFACE_DESC_SIZE 9+7+7
+#define EXPERIMENTAL_HID_DESC_OFFSET	MULTITOUCH_INTERFACE_DESC_POS+9
+#else
+#define EXPERIMENTAL_INTERFACE_DESC_SIZE 0
+#endif
+
+#define CONFIG_DESC_SIZE		EXPERIMENTAL_INTERFACE_DESC_POS+EXPERIMENTAL_INTERFACE_DESC_SIZE
 
 
 
         0x03,                                   // bmAttributes (0x03=intr)
         MULTITOUCH_SIZE, 0,                     // wMaxPacketSize
         4,                                      // bInterval, 4 = 1ms
-#endif // KEYMEDIA_INTERFACE
+#endif // MULTITOUCH_INTERFACE
+
+#ifdef EXPERIMENTAL_INTERFACE
+	// configuration for 480 Mbit/sec speed
+        // interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
+        9,                                      // bLength
+        4,                                      // bDescriptorType
+        EXPERIMENTAL_INTERFACE,                 // bInterfaceNumber
+        0,                                      // bAlternateSetting
+        1,                                      // bNumEndpoints
+        0xFF,                                   // bInterfaceClass (0xFF = Vendor)
+        0x6A,                                   // bInterfaceSubClass
+        0xFF,                                   // bInterfaceProtocol
+        0,                                      // iInterface
+        // endpoint descriptor, USB spec 9.6.6, page 269-271, Table 9-13
+        7,                                      // bLength
+        5,                                      // bDescriptorType
+        1 | 0x80,                               // bEndpointAddress
+        0x02,                                   // bmAttributes (0x02=bulk)
+        LSB(512), MSB(512),                     // wMaxPacketSize
+        1,                                      // bInterval
+        // endpoint descriptor, USB spec 9.6.6, page 269-271, Table 9-13
+        7,                                      // bLength
+        5,                                      // bDescriptorType
+        1,                                      // bEndpointAddress
+        0x02,                                   // bmAttributes (0x02=bulk)
+        LSB(512), MSB(512),                     // wMaxPacketSize
+        1,                                      // bInterval
+#endif // EXPERIMENTAL_INTERFACE
 };
 
 
         0x03,                                   // bmAttributes (0x03=intr)
         MULTITOUCH_SIZE, 0,                     // wMaxPacketSize
         1,                                      // bInterval
-#endif // KEYMEDIA_INTERFACE
+#endif // MULTITOUCH_INTERFACE
+
+#ifdef EXPERIMENTAL_INTERFACE
+	// configuration for 12 Mbit/sec speed
+        // interface descriptor, USB spec 9.6.5, page 267-269, Table 9-12
+        9,                                      // bLength
+        4,                                      // bDescriptorType
+        EXPERIMENTAL_INTERFACE,                 // bInterfaceNumber
+        0,                                      // bAlternateSetting
+        1,                                      // bNumEndpoints
+        0xFF,                                   // bInterfaceClass (0xFF = Vendor)
+        0x6A,                                   // bInterfaceSubClass
+        0xFF,                                   // bInterfaceProtocol
+        0,                                      // iInterface
+        // endpoint descriptor, USB spec 9.6.6, page 269-271, Table 9-13
+        7,                                      // bLength
+        5,                                      // bDescriptorType
+        1 | 0x80,                               // bEndpointAddress
+        0x02,                                   // bmAttributes (0x02=bulk)
+        LSB(64), MSB(64),                       // wMaxPacketSize
+        1,                                      // bInterval
+        // endpoint descriptor, USB spec 9.6.6, page 269-271, Table 9-13
+        7,                                      // bLength
+        5,                                      // bDescriptorType
+        1,                                      // bEndpointAddress
+        0x02,                                   // bmAttributes (0x02=bulk)
+        LSB(64), MSB(64),                       // wMaxPacketSize
+        1,                                      // bInterval
+#endif // EXPERIMENTAL_INTERFACE
 };
 
 

teensy4/usb_desc.h

   #define EP0_SIZE		64
   #define NUM_ENDPOINTS		4
   #define NUM_USB_BUFFERS	12
-  #define NUM_INTERFACE		2
+  #define NUM_INTERFACE		3
   #define CDC_STATUS_INTERFACE	0
   #define CDC_DATA_INTERFACE	1
   #define CDC_ACM_ENDPOINT	2
   #define CDC_TX_SIZE_480       512
   #define CDC_RX_SIZE_12        64
   #define CDC_TX_SIZE_12        64
+  #define EXPERIMENTAL_INTERFACE 2
   #define ENDPOINT2_CONFIG	ENDPOINT_RECEIVE_UNUSED + ENDPOINT_TRANSMIT_INTERRUPT
   #define ENDPOINT3_CONFIG	ENDPOINT_RECEIVE_BULK + ENDPOINT_TRANSMIT_UNUSED
   #define ENDPOINT4_CONFIG      ENDPOINT_RECEIVE_UNUSED + ENDPOINT_TRANSMIT_BULK