Added beginnings of a new AVRISP-MKII clone project.

Added new Endpoint_SetEndpointDirection() macro to set the current endpoint direction for bidirectional endpoints.

Renamed internal USB_INT_ENDPOINT_SETUP macro to USB_INT_RXSTPI to fit in with the rest of the interrupt vector macros.

Bootloaders/CDC/makefile

@@ -48,7 +48,7 @@
 
 
 # MCU name
-MCU = at90usb647
+MCU = at90usb1287
 
 
 # Target board (see library "Board Types" documentation, USER or blank for projects not requiring

LUFA/Drivers/USB/HighLevel/USBInterrupt.c

@@ -148,7 +148,7 @@ ISR(USB_GEN_vect, ISR_BLOCK)
 		                           ENDPOINT_BANK_SINGLE);
 
 		#if defined(INTERRUPT_CONTROL_ENDPOINT)
-		USB_INT_Enable(USB_INT_ENDPOINT_SETUP);
+		USB_INT_Enable(USB_INT_RXSTPI);
 		#endif
 
 		EVENT_USB_Device_Reset();
@@ -236,7 +236,7 @@ ISR(USB_COM_vect, ISR_BLOCK)
 
 	USB_USBTask();
 
-	USB_INT_Clear(USB_INT_ENDPOINT_SETUP);
+	USB_INT_Clear(USB_INT_RXSTPI);
 	
 	Endpoint_SelectEndpoint(PrevSelectedEndpoint);
 }

LUFA/Drivers/USB/HighLevel/USBInterrupt.h

@@ -72,7 +72,7 @@
 			#define USB_INT_HSOFI                            UHIEN,  (1 << HSOFE)  , UHINT , (1 << HSOFI)
 			#define USB_INT_RSTI                             UHIEN , (1 << RSTE)   , UHINT , (1 << RSTI)
 			#define USB_INT_SRPI                             OTGIEN, (1 << SRPE)   , OTGINT, (1 << SRPI)
-			#define USB_INT_ENDPOINT_SETUP                   UEIENX, (1 << RXSTPE) , UEINTX, (1 << RXSTPI)
+			#define USB_INT_RXSTPI                           UEIENX, (1 << RXSTPE) , UEINTX, (1 << RXSTPI)
 	
 		/* Function Prototypes: */
 			void USB_INT_ClearAllInterrupts(void);

LUFA/Drivers/USB/LowLevel/Endpoint.h

@@ -331,6 +331,12 @@
 				 *  \return The currently selected endpoint's direction, as a ENDPOINT_DIR_* mask.
 				 */
 				static inline uint8_t Endpoint_GetEndpointDirection(void);
+
+				/** Sets the direction of the currently selected endpoint.
+				 *
+				 *  \param DirectionMask  New endpoint direction, as a ENDPOINT_DIR_* mask.
+				 */
+				static inline void Endpoint_SetEndpointDirection(uint8_t DirectionMask);
 			#else
 				#if defined(USB_SERIES_4_AVR) || defined(USB_SERIES_6_AVR) || defined(USB_SERIES_7_AVR) || defined(__DOXYGEN__)
 					#define Endpoint_BytesInEndpoint()        UEBCX
@@ -399,6 +405,8 @@
 				#define Endpoint_ResetDataToggle()            MACROS{ UECONX |= (1 << RSTDT); }MACROE
 				
 				#define Endpoint_GetEndpointDirection()       (UECFG0X & ENDPOINT_DIR_IN)
+				
+				#define Endpoint_SetEndpointDirection(dir)    MACROS{ UECFG0X = ((UECFG0X & ~ENDPOINT_DIR_IN) | dir); }MACROE
 			#endif
 
 		/* Enums: */

LUFA/ManPages/ChangeLog.txt

@@ -13,6 +13,8 @@
   *  - Added flag to the HID report parser to indicate if a device has multiple reports
   *  - Added new EVENT_USB_Device_StartOfFrame() event, controlled by the new USB_Device_EnableSOFEvents() and
   *    USB_Device_DisableSOFEvents() macros to give bus-synchronised millisecond interrupts when in USB device mode
+  *  - Added new Endpoint_SetEndpointDirection() macro for bi-directional endpoints
+  *  - Added new AVRISP project, a LUFA clone of the Atmel AVRISP-MKII programmer
   *  
   *  <b>Changed:</b>
   *  - SetIdle requests to the HID device driver with a 0 idle period (send changes only) now only affect the requested

LUFA/ManPages/FutureChanges.txt

@@ -12,9 +12,10 @@
   *  or post your suggestion as an enhancement request to the project bug tracker.
   *
   *  <b>Targeted for This Release:</b>
-  *  - Host Mode Class Drivers
+  *  - Finish Host Mode Class Drivers
   *  - Add overviews of each of the officially supported boards to the manual
   *  - Add hub support to match Atmel's stack
+  *  - Finish AVRISP Project
   *
   *  <b>Targeted for Future Releases:</b>
   *  - Add standardized descriptor names to device and host class driver structures

Projects/AVRISP/AVRISP.c

+/*
+             LUFA Library
+     Copyright (C) Dean Camera, 2009.
+              
+  dean [at] fourwalledcubicle [dot] com
+      www.fourwalledcubicle.com
+*/
+
+/*
+  Copyright 2009  Dean Camera (dean [at] fourwalledcubicle [dot] com)
+
+  Permission to use, copy, modify, and distribute this software
+  and its documentation for any purpose and without fee is hereby
+  granted, provided that the above copyright notice appear in all
+  copies and that both that the copyright notice and this
+  permission notice and warranty disclaimer appear in supporting
+  documentation, and that the name of the author not be used in
+  advertising or publicity pertaining to distribution of the
+  software without specific, written prior permission.
+
+  The author disclaim all warranties with regard to this
+  software, including all implied warranties of merchantability
+  and fitness.  In no event shall the author be liable for any
+  special, indirect or consequential damages or any damages
+  whatsoever resulting from loss of use, data or profits, whether
+  in an action of contract, negligence or other tortious action,
+  arising out of or in connection with the use or performance of
+  this software.
+*/
+
+/** \file
+ *
+ *  Main source file for the AVRISP project. This file contains the main tasks of
+ *  the project and is responsible for the initial application hardware configuration.
+ */
+
+#include "AVRISP.h"
+
+/** Main program entry point. This routine contains the overall program flow, including initial
+ *  setup of all components and the main program loop.
+ */
+int main(void)
+{
+	SetupHardware();
+	
+	printf("AVRISP-MKII\r\n");
+	
+	LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
+
+	for (;;)
+	{
+		Process_AVRISP_Commands();
+
+		USB_USBTask();
+	}
+}
+
+/** Configures the board hardware and chip peripherals for the demo's functionality. */
+void SetupHardware(void)
+{
+	/* Disable watchdog if enabled by bootloader/fuses */
+	MCUSR &= ~(1 << WDRF);
+	wdt_disable();
+
+	/* Disable clock division */
+	clock_prescale_set(clock_div_1);
+
+	/* Hardware Initialization */
+	SerialStream_Init(9600, false);
+	LEDs_Init();
+	USB_Init();
+}
+
+/** Event handler for the library USB Connection event. */
+void EVENT_USB_Device_Connect(void)
+{
+	LEDs_SetAllLEDs(LEDMASK_USB_ENUMERATING);
+}
+
+/** Event handler for the library USB Disconnection event. */
+void EVENT_USB_Device_Disconnect(void)
+{
+	LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
+}
+
+/** Event handler for the library USB Configuration Changed event. */
+void EVENT_USB_Device_ConfigurationChanged(void)
+{
+	/* Indicate USB connected and ready */
+	LEDs_SetAllLEDs(LEDMASK_USB_READY);
+
+	/* Setup AVRISP data Endpoints */
+	if (!(Endpoint_ConfigureEndpoint(AVRISP_DATA_EPNUM, EP_TYPE_BULK,
+		                             ENDPOINT_DIR_OUT, AVRISP_DATA_EPSIZE,
+	                                 ENDPOINT_BANK_SINGLE)))
+	{
+		LEDs_SetAllLEDs(LEDMASK_USB_ERROR);
+	}
+}
+
+void EVENT_USB_Device_UnhandledControlRequest(void)
+{
+	printf("CONTROL REQUEST\r\n");
+}
+
+void Process_AVRISP_Commands(void)
+{
+	/* Device must be connected and configured for the task to run */
+	if (USB_DeviceState != DEVICE_STATE_Configured)
+	  return;
+
+	Endpoint_SelectEndpoint(AVRISP_DATA_EPNUM);
+	
+	/* Check to see if a V2 Protocol command has been received - if not, abort */
+	if (!(Endpoint_IsOUTReceived()))
+	  return;
+	  
+	printf("COMMAND\r\n");
+
+	/* Pass off processing of the V2 Protocol command to the V2 Protocol handler */
+	V2Protocol_ProcessCommand();
+
+	/* Reset Endpoint direction to OUT ready for next command */
+	Endpoint_SetEndpointDirection(ENDPOINT_DIR_OUT);
+}
+

Projects/AVRISP/AVRISP.h

+/*
+             LUFA Library
+     Copyright (C) Dean Camera, 2009.
+              
+  dean [at] fourwalledcubicle [dot] com
+      www.fourwalledcubicle.com
+*/
+
+/*
+  Copyright 2009  Dean Camera (dean [at] fourwalledcubicle [dot] com)
+
+  Permission to use, copy, modify, and distribute this software
+  and its documentation for any purpose and without fee is hereby
+  granted, provided that the above copyright notice appear in all
+  copies and that both that the copyright notice and this
+  permission notice and warranty disclaimer appear in supporting
+  documentation, and that the name of the author not be used in
+  advertising or publicity pertaining to distribution of the
+  software without specific, written prior permission.
+
+  The author disclaim all warranties with regard to this
+  software, including all implied warranties of merchantability
+  and fitness.  In no event shall the author be liable for any
+  special, indirect or consequential damages or any damages
+  whatsoever resulting from loss of use, data or profits, whether
+  in an action of contract, negligence or other tortious action,
+  arising out of or in connection with the use or performance of
+  this software.
+*/
+
+/** \file
+ *
+ *  Header file for AVRISP.c.
+ */
+
+#ifndef _AVRISP_H_
+#define _AVRISP_H_
+
+	/* Includes: */
+		#include <avr/io.h>
+		#include <avr/wdt.h>
+		#include <avr/interrupt.h>
+		#include <avr/power.h>
+
+		#include "Descriptors.h"
+
+		#include <LUFA/Version.h>
+		#include <LUFA/Drivers/Board/LEDs.h>
+		#include <LUFA/Drivers/Peripheral/SerialStream.h>
+		#include <LUFA/Drivers/USB/USB.h>
+
+		#include "Lib/V2Protocol.h"
+
+	/* Macros: */
+		/** LED mask for the library LED driver, to indicate that the USB interface is not ready. */
+		#define LEDMASK_USB_NOTREADY      LEDS_LED1
+
+		/** LED mask for the library LED driver, to indicate that the USB interface is enumerating. */
+		#define LEDMASK_USB_ENUMERATING  (LEDS_LED2 | LEDS_LED3)
+
+		/** LED mask for the library LED driver, to indicate that the USB interface is ready. */
+		#define LEDMASK_USB_READY        (LEDS_LED2 | LEDS_LED4)
+
+		/** LED mask for the library LED driver, to indicate that an error has occurred in the USB interface. */
+		#define LEDMASK_USB_ERROR        (LEDS_LED1 | LEDS_LED3)		
+
+	/* Function Prototypes: */
+		void SetupHardware(void);
+
+		void EVENT_USB_Device_Connect(void);
+		void EVENT_USB_Device_Disconnect(void);
+		void EVENT_USB_Device_ConfigurationChanged(void);
+		void EVENT_USB_Device_UnhandledControlRequest(void);
+
+		void Process_AVRISP_Commands(void);
+		
+#endif

Projects/AVRISP/AVRISP.txt

+/** \file
+ *
+ *  This file contains special DoxyGen information for the generation of the main page and other special
+ *  documentation pages. It is not a project source file.
+ */
+ 
+/** \mainpage AVRISP MKII Programmer Project
+ *
+ *  \section SSec_Compat Demo Compatibility:
+ *
+ *  The following table indicates what microcontrollers are compatible with this demo.
+ *
+ *  - AT90USB1287
+ *  - AT90USB1286
+ *  - AT90USB647
+ *  - AT90USB646
+ *  - ATMEGA32U6
+ *  - ATMEGA32U4
+ *  - ATMEGA16U4
+ *  - AT90USB162
+ *  - AT90USB82
+ *
+ *  \section SSec_Info USB Information:
+ *
+ *  The following table gives a rundown of the USB utilization of this demo.
+ *
+ * <table>
+ *  <tr>
+ *   <td><b>USB Mode:</b></td>
+ *   <td>Device</td>
+ *  </tr>
+ *  <tr>
+ *   <td><b>USB Class:</b></td>
+ *   <td>Vendor Specific Class</td>
+ *  </tr>
+ *  <tr> 
+ *   <td><b>USB Subclass:</b></td>
+ *   <td>N/A</td>
+ *  </tr>
+ *  <tr>
+ *   <td><b>Relevant Standards:</b></td>
+ *   <td>Atmel AVRISP MKII Protocol Specification</td>
+ *  </tr>
+ *  <tr>
+ *   <td><b>Usable Speeds:</b></td>
+ *   <td>Full Speed Mode</td>
+ *  </tr>
+ * </table>
+ *
+ *  \section SSec_Description Project Description: 
+ *
+ *  Firmware for an AVRStudio compatible AVRISP-MKII clone programmer. This project will enable the USB AVR series of
+ *  microcontrollers to act as a clone of the official Atmel AVRISP-MKII programmer, usable within AVRStudio.
+ *
+ *  This device spoofs Atmel's official AVRISP-MKII device PID so that it remains compatible with Atmel's AVRISP-MKII
+ *  drivers. When promted, direct your OS to install Atmel's AVRISP-MKII drivers provided with AVRStudio.
+ *
+ *  \section SSec_Options Project Options
+ *
+ *  The following defines can be found in this demo, which can control the demo behaviour when defined, or changed in value.
+ *
+ *  <table>
+ *   <tr>
+ *    <td>
+ *     None
+ *    </td>
+ *   </tr>
+ *  </table>
+ */

Projects/AVRISP/Descriptors.c

+/*
+             LUFA Library
+     Copyright (C) Dean Camera, 2009.
+              
+  dean [at] fourwalledcubicle [dot] com
+      www.fourwalledcubicle.com
+*/
+
+/*
+  Copyright 2009  Dean Camera (dean [at] fourwalledcubicle [dot] com)
+
+  Permission to use, copy, modify, and distribute this software
+  and its documentation for any purpose and without fee is hereby
+  granted, provided that the above copyright notice appear in all
+  copies and that both that the copyright notice and this
+  permission notice and warranty disclaimer appear in supporting
+  documentation, and that the name of the author not be used in
+  advertising or publicity pertaining to distribution of the
+  software without specific, written prior permission.
+
+  The author disclaim all warranties with regard to this
+  software, including all implied warranties of merchantability
+  and fitness.  In no event shall the author be liable for any
+  special, indirect or consequential damages or any damages
+  whatsoever resulting from loss of use, data or profits, whether
+  in an action of contract, negligence or other tortious action,
+  arising out of or in connection with the use or performance of
+  this software.
+*/
+
+/** \file
+ *
+ *  USB Device Descriptors, for library use when in USB device mode. Descriptors are special 
+ *  computer-readable structures which the host requests upon device enumeration, to determine
+ *  the device's capabilities and functions.  
+ */
+
+#include "Descriptors.h"
+
+/** Device descriptor structure. This descriptor, located in FLASH memory, describes the overall
+ *  device characteristics, including the supported USB version, control endpoint size and the
+ *  number of device configurations. The descriptor is read out by the USB host when the enumeration
+ *  process begins.
+ */
+USB_Descriptor_Device_t PROGMEM DeviceDescriptor =
+{
+	.Header                 = {.Size = sizeof(USB_Descriptor_Device_t), .Type = DTYPE_Device},
+		
+	.USBSpecification       = VERSION_BCD(01.10),
+	.Class                  = 0xFF,
+	.SubClass               = 0x00,
+	.Protocol               = 0x00,
+				
+	.Endpoint0Size          = FIXED_CONTROL_ENDPOINT_SIZE,
+		
+	.VendorID               = 0x03EB,
+	.ProductID              = 0x2104,
+	.ReleaseNumber          = VERSION_BCD(02.00),
+		
+	.ManufacturerStrIndex   = 0x01,
+	.ProductStrIndex        = 0x02,
+	.SerialNumStrIndex      = 0x03,
+		
+	.NumberOfConfigurations = FIXED_NUM_CONFIGURATIONS
+};
+
+/** Configuration descriptor structure. This descriptor, located in FLASH memory, describes the usage
+ *  of the device in one of its supported configurations, including information about any device interfaces
+ *  and endpoints. The descriptor is read out by the USB host during the enumeration process when selecting
+ *  a configuration so that the host may correctly communicate with the USB device.
+ */
+USB_Descriptor_Configuration_t PROGMEM ConfigurationDescriptor =
+{
+	.Config = 
+		{
+			.Header                 = {.Size = sizeof(USB_Descriptor_Configuration_Header_t), .Type = DTYPE_Configuration},
+
+			.TotalConfigurationSize = sizeof(USB_Descriptor_Configuration_t),
+			.TotalInterfaces        = 1,
+				
+			.ConfigurationNumber    = 1,
+			.ConfigurationStrIndex  = NO_DESCRIPTOR,
+				
+			.ConfigAttributes       = USB_CONFIG_ATTR_SELFPOWERED,
+			
+			.MaxPowerConsumption    = USB_CONFIG_POWER_MA(100)
+		},
+
+	.AVRISPInterface = 
+		{
+			.Header                 = {.Size = sizeof(USB_Descriptor_Interface_t), .Type = DTYPE_Interface},
+
+			.InterfaceNumber        = 0,
+			.AlternateSetting       = 0,
+			
+			.TotalEndpoints         = 2,
+				
+			.Class                  = 0xFF,
+			.SubClass               = 0x00,
+			.Protocol               = 0x00,
+				
+			.InterfaceStrIndex      = NO_DESCRIPTOR
+		},
+
+	.DataInEndpoint = 
+		{
+			.Header                 = {.Size = sizeof(USB_Descriptor_Endpoint_t), .Type = DTYPE_Endpoint},
+			
+			.EndpointAddress        = (ENDPOINT_DESCRIPTOR_DIR_IN | AVRISP_DATA_EPNUM),
+			.Attributes             = (EP_TYPE_BULK | ENDPOINT_ATTR_NO_SYNC | ENDPOINT_USAGE_DATA),
+			.EndpointSize           = AVRISP_DATA_EPSIZE,
+			.PollingIntervalMS      = 0x0A
+		},
+
+	.DataOutEndpoint =
+		{
+			.Header                 = {.Size = sizeof(USB_Descriptor_Endpoint_t), .Type = DTYPE_Endpoint},
+			
+			.EndpointAddress        = (ENDPOINT_DESCRIPTOR_DIR_OUT | AVRISP_DATA_EPNUM),
+			.Attributes             = (EP_TYPE_BULK | ENDPOINT_ATTR_NO_SYNC | ENDPOINT_USAGE_DATA),
+			.EndpointSize           = AVRISP_DATA_EPSIZE,
+			.PollingIntervalMS      = 0x0A
+		},
+};
+
+/** Language descriptor structure. This descriptor, located in FLASH memory, is returned when the host requests
+ *  the string descriptor with index 0 (the first index). It is actually an array of 16-bit integers, which indicate
+ *  via the language ID table available at USB.org what languages the device supports for its string descriptors.
+ */
+USB_Descriptor_String_t PROGMEM LanguageString =
+{
+	.Header                 = {.Size = USB_STRING_LEN(1), .Type = DTYPE_String},
+		
+	.UnicodeString          = {LANGUAGE_ID_ENG}
+};
+
+/** Manufacturer descriptor string. This is a Unicode string containing the manufacturer's details in human readable
+ *  form, and is read out upon request by the host when the appropriate string ID is requested, listed in the Device
+ *  Descriptor.
+ */
+USB_Descriptor_String_t PROGMEM ManufacturerString =
+{
+	.Header                 = {.Size = USB_STRING_LEN(5), .Type = DTYPE_String},
+		
+	.UnicodeString          = L"ATMEL"
+};
+
+/** Product descriptor string. This is a Unicode string containing the product's details in human readable form,
+ *  and is read out upon request by the host when the appropriate string ID is requested, listed in the Device
+ *  Descriptor.
+ */
+USB_Descriptor_String_t PROGMEM ProductString =
+{
+	.Header                 = {.Size = USB_STRING_LEN(11), .Type = DTYPE_String},
+		
+	.UnicodeString          = L"AVRISP mkII"
+};
+
+USB_Descriptor_String_t PROGMEM SerialString =
+{
+	.Header                 = {.Size = USB_STRING_LEN(12), .Type = DTYPE_String},
+		
+	.UnicodeString          = L"00A000001B5B"
+};
+
+/** This function is called by the library when in device mode, and must be overridden (see library "USB Descriptors"
+ *  documentation) by the application code so that the address and size of a requested descriptor can be given
+ *  to the USB library. When the device receives a Get Descriptor request on the control endpoint, this function
+ *  is called so that the descriptor details can be passed back and the appropriate descriptor sent back to the
+ *  USB host.
+ */
+uint16_t CALLBACK_USB_GetDescriptor(const uint16_t wValue, const uint8_t wIndex, void** const DescriptorAddress)
+{
+	const uint8_t  DescriptorType   = (wValue >> 8);
+	const uint8_t  DescriptorNumber = (wValue & 0xFF);
+
+	void*    Address = NULL;
+	uint16_t Size    = NO_DESCRIPTOR;
+
+	switch (DescriptorType)
+	{
+		case DTYPE_Device: 
+			Address = (void*)&DeviceDescriptor;
+			Size    = sizeof(USB_Descriptor_Device_t);
+			break;
+		case DTYPE_Configuration: 
+			Address = (void*)&ConfigurationDescriptor;
+			Size    = sizeof(USB_Descriptor_Configuration_t);
+			break;
+		case DTYPE_String: 
+			switch (DescriptorNumber)
+			{
+				case 0x00: 
+					Address = (void*)&LanguageString;
+					Size    = pgm_read_byte(&LanguageString.Header.Size);
+					break;
+				case 0x01: 
+					Address = (void*)&ManufacturerString;
+					Size    = pgm_read_byte(&ManufacturerString.Header.Size);
+					break;
+				case 0x02: 
+					Address = (void*)&ProductString;
+					Size    = pgm_read_byte(&ProductString.Header.Size);
+					break;
+				case 0x03:
+					Address = (void*)&SerialString;
+					Size    = pgm_read_byte(&SerialString.Header.Size);
+					break;					
+			}
+			
+			break;
+	}
+	
+	*DescriptorAddress = Address;
+	return Size;
+}

Projects/AVRISP/Descriptors.h

+/*
+             LUFA Library
+     Copyright (C) Dean Camera, 2009.
+              
+  dean [at] fourwalledcubicle [dot] com
+      www.fourwalledcubicle.com
+*/
+
+/*
+  Copyright 2009  Dean Camera (dean [at] fourwalledcubicle [dot] com)
+
+  Permission to use, copy, modify, and distribute this software
+  and its documentation for any purpose and without fee is hereby
+  granted, provided that the above copyright notice appear in all
+  copies and that both that the copyright notice and this
+  permission notice and warranty disclaimer appear in supporting
+  documentation, and that the name of the author not be used in
+  advertising or publicity pertaining to distribution of the
+  software without specific, written prior permission.
+
+  The author disclaim all warranties with regard to this
+  software, including all implied warranties of merchantability
+  and fitness.  In no event shall the author be liable for any
+  special, indirect or consequential damages or any damages
+  whatsoever resulting from loss of use, data or profits, whether
+  in an action of contract, negligence or other tortious action,
+  arising out of or in connection with the use or performance of
+  this software.
+*/
+
+/** \file
+ *
+ *  Header file for Descriptors.c.
+ */
+ 
+#ifndef _DESCRIPTORS_H_
+#define _DESCRIPTORS_H_
+
+	/* Includes: */
+		#include <avr/pgmspace.h>
+
+		#include <LUFA/Drivers/USB/USB.h>
+		#include <LUFA/Drivers/USB/Class/CDC.h>
+
+	/* Macros: */
+		/** Endpoint number of the AVRISP bidirectional data endpoint. */
+		#define AVRISP_DATA_EPNUM              2
+
+		/** Size in bytes of the AVRISP data endpoint. */
+		#define AVRISP_DATA_EPSIZE             64	
+
+	/* Type Defines: */
+		/** Type define for the device configuration descriptor structure. This must be defined in the
+		 *  application code, as the configuration descriptor contains several sub-descriptors which
+		 *  vary between devices, and which describe the device's usage to the host.
+		 */