1 files changed, 183 insertions, 0 deletions
diff --git a/lib/lufa/Demos/Host/LowLevel/GenericHIDHost/ConfigDescriptor.c b/lib/lufa/Demos/Host/LowLevel/GenericHIDHost/ConfigDescriptor.c
new file mode 100644
index 0000000000..c98f0fbcec
--- /dev/null
+++ b/lib/lufa/Demos/Host/LowLevel/GenericHIDHost/ConfigDescriptor.c
@@ -0,0 +1,183 @@
+/*
+             LUFA Library
+     Copyright (C) Dean Camera, 2017.
+
+  dean [at] fourwalledcubicle [dot] com
+           www.lufa-lib.org
+*/
+
+/*
+  Copyright 2017  Dean Camera (dean [at] fourwalledcubicle [dot] com)
+
+  Permission to use, copy, modify, distribute, and sell this
+  software and its documentation for any purpose is hereby granted
+  without fee, 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 disclaims 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 Configuration Descriptor processing routines, to determine the correct pipe configurations
+ *  needed to communication with an attached USB device. Descriptors are special  computer-readable structures
+ *  which the host requests upon device enumeration, to determine the device's capabilities and functions.
+ */
+
+#include "ConfigDescriptor.h"
+
+/** Reads and processes an attached device's descriptors, to determine compatibility and pipe configurations. This
+ *  routine will read in the entire configuration descriptor, and configure the hosts pipes to correctly communicate
+ *  with compatible devices.
+ *
+ *  This routine searches for a HID interface descriptor containing at least one Interrupt type IN endpoint.
+ *
+ *  \return An error code from the \ref GenericHIDHost_GetConfigDescriptorDataCodes_t enum.
+ */
+uint8_t ProcessConfigurationDescriptor(void)
+{
+	uint8_t  ConfigDescriptorData[512];
+	void*    CurrConfigLocation = ConfigDescriptorData;
+	uint16_t CurrConfigBytesRem;
+
+	USB_Descriptor_Interface_t* HIDInterface    = NULL;
+	USB_Descriptor_Endpoint_t*  DataINEndpoint  = NULL;
+	USB_Descriptor_Endpoint_t*  DataOUTEndpoint = NULL;
+
+	/* Retrieve the entire configuration descriptor into the allocated buffer */
+	switch (USB_Host_GetDeviceConfigDescriptor(1, &CurrConfigBytesRem, ConfigDescriptorData, sizeof(ConfigDescriptorData)))
+	{
+		case HOST_GETCONFIG_Successful:
+			break;
+		case HOST_GETCONFIG_InvalidData:
+			return InvalidConfigDataReturned;
+		case HOST_GETCONFIG_BuffOverflow:
+			return DescriptorTooLarge;
+		default:
+			return ControlError;
+	}
+
+	while (!(DataINEndpoint) || !(DataOUTEndpoint))
+	{
+		/* See if we've found a likely compatible interface, and if there is an endpoint within that interface */
+		if (!(HIDInterface) ||
+		    USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
+		                              DComp_NextHIDInterfaceDataEndpoint) != DESCRIPTOR_SEARCH_COMP_Found)
+		{
+			/* Not all HID devices have an OUT endpoint - if we've reached the end of the HID descriptor
+			 * but only found the mandatory IN endpoint, it's safe to continue with the device enumeration */
+			if (DataINEndpoint)
+			  break;
+
+			/* Get the next HID interface from the configuration descriptor */
+			if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
+										  DComp_NextHIDInterface) != DESCRIPTOR_SEARCH_COMP_Found)
+			{
+				/* Descriptor not found, error out */
+				return NoCompatibleInterfaceFound;
+			}
+
+			/* Save the interface in case we need to refer back to it later */
+			HIDInterface = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t);
+
+			/* Clear any found endpoints */
+			DataOUTEndpoint = NULL;
+
+			/* Skip the remainder of the loop as we have not found an endpoint yet */
+			continue;
+		}
+
+		/* Retrieve the endpoint address from the endpoint descriptor */
+		USB_Descriptor_Endpoint_t* EndpointData = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Endpoint_t);
+
+		/* If the endpoint is a IN type endpoint */
+		if ((EndpointData->EndpointAddress & ENDPOINT_DIR_MASK) == ENDPOINT_DIR_IN)
+		  DataINEndpoint = EndpointData;
+		else
+		  DataOUTEndpoint = EndpointData;
+	}
+
+	/* Configure the HID data IN pipe */
+	Pipe_ConfigurePipe(HID_DATA_IN_PIPE, EP_TYPE_INTERRUPT, DataINEndpoint->EndpointAddress, DataINEndpoint->EndpointSize, 1);
+	Pipe_SetInterruptPeriod(DataINEndpoint->PollingIntervalMS);
+
+	/* Check if the HID interface contained an optional OUT data endpoint */
+	if (DataOUTEndpoint)
+	{
+		/* Configure the HID data OUT pipe */
+		Pipe_ConfigurePipe(HID_DATA_OUT_PIPE, EP_TYPE_INTERRUPT, DataOUTEndpoint->EndpointAddress, DataOUTEndpoint->EndpointSize, 1);
+	}
+
+	/* Valid data found, return success */
+	return SuccessfulConfigRead;
+}
+
+/** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's
+ *  configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration
+ *  descriptor processing if an incompatible descriptor configuration is found.
+ *
+ *  This comparator searches for the next Interface descriptor of the correct HID Class value.
+ *
+ *  \return A value from the DSEARCH_Return_ErrorCodes_t enum
+ */
+uint8_t DComp_NextHIDInterface(void* CurrentDescriptor)
+{
+	USB_Descriptor_Header_t* Header = DESCRIPTOR_PCAST(CurrentDescriptor, USB_Descriptor_Header_t);
+
+	/* Determine if the current descriptor is an interface descriptor */
+	if (Header->Type == DTYPE_Interface)
+	{
+		USB_Descriptor_Interface_t* Interface = DESCRIPTOR_PCAST(CurrentDescriptor, USB_Descriptor_Interface_t);
+
+		/* Check the HID descriptor class, break out if correct class/protocol interface found */
+		if (Interface->Class == HID_CSCP_HIDClass)
+		{
+			/* Indicate that the descriptor being searched for has been found */
+			return DESCRIPTOR_SEARCH_Found;
+		}
+	}
+
+	/* Current descriptor does not match what this comparator is looking for */
+	return DESCRIPTOR_SEARCH_NotFound;
+}
+
+/** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's
+ *  configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration
+ *  descriptor processing if an incompatible descriptor configuration is found.
+ *
+ *  This comparator searches for the next Endpoint descriptor inside the current interface descriptor,
+ *  aborting the search if another interface descriptor is found before the required endpoint.
+ *
+ *  \return A value from the DSEARCH_Return_ErrorCodes_t enum
+ */
+uint8_t DComp_NextHIDInterfaceDataEndpoint(void* CurrentDescriptor)
+{
+	USB_Descriptor_Header_t* Header = DESCRIPTOR_PCAST(CurrentDescriptor, USB_Descriptor_Header_t);
+
+	/* Determine the type of the current descriptor */
+	if (Header->Type == DTYPE_Endpoint)
+	{
+		/* Indicate that the descriptor being searched for has been found */
+		return DESCRIPTOR_SEARCH_Found;
+	}
+	else if (Header->Type == DTYPE_Interface)
+	{
+		/* Indicate that the search has failed prematurely and should be aborted */
+		return DESCRIPTOR_SEARCH_Fail;
+	}
+
+	/* Current descriptor does not match what this comparator is looking for */
+	return DESCRIPTOR_SEARCH_NotFound;
+}
+