hidparser.c

userial is an Free project building an USB to I2C/SPI/GPIO bridge, using the Atmel AT90USB647 chip.

/*
             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.
*/

#include "HIDParser.h"

uint8_t ProcessHIDReport(const uint8_t* ReportData, uint16_t ReportSize, HID_ReportInfo_t* const ParserData)
{
	HID_StateTable_t  StateTable[HID_STATETABLE_STACK_DEPTH];
	HID_StateTable_t* CurrStateTable               = &StateTable[0];
	uint16_t          UsageStack[HID_USAGE_STACK_DEPTH];
	uint8_t           UsageStackSize               = 0;
	uint16_t          BitOffsetIn                  = 0;
	uint16_t          BitOffsetOut                 = 0;
#if defined(HID_ENABLE_FEATURE_PROCESSING)
	uint16_t          BitOffsetFeature             = 0;
#endif
	HID_CollectionPath_t* CurrCollectionPath       = NULL;

	memset((void*)ParserData, 0x00, sizeof(HID_ReportInfo_t));
	memset((void*)StateTable, 0x00, sizeof(StateTable));

	while (ReportSize)
	{
		uint32_t ReportItemData = 0;
		
		switch (*ReportData & DATA_SIZE_MASK)
		{
			case DATA_SIZE_4:
				ReportItemData = *((uint32_t*)(ReportData + 1));
				break;
			case DATA_SIZE_2:
				ReportItemData = *((uint16_t*)(ReportData + 1));
				break;
			case DATA_SIZE_1:
				ReportItemData = *((uint8_t*)(ReportData + 1));
				break;
		}

		switch (*ReportData & (TYPE_MASK | TAG_MASK))
		{
			case (TYPE_GLOBAL | TAG_GLOBAL_PUSH):
				if (CurrStateTable == &StateTable[HID_STATETABLE_STACK_DEPTH])
				  return HID_PARSE_HIDStackOverflow;
	
				memcpy((CurrStateTable - 1),
				       CurrStateTable,
				       sizeof(HID_ReportItem_t));

				CurrStateTable++;
				break;
			case (TYPE_GLOBAL | TAG_GLOBAL_POP):
				if (CurrStateTable == &StateTable[0])
				  return HID_PARSE_HIDStackUnderflow;
				  
				CurrStateTable--;
				break;
			case (TYPE_GLOBAL | TAG_GLOBAL_USAGEPAGE):
				CurrStateTable->Attributes.Usage.Page       = ReportItemData;
				break;
			case (TYPE_GLOBAL | TAG_GLOBAL_LOGICALMIN):
				CurrStateTable->Attributes.Logical.Minimum  = ReportItemData;
				break;
			case (TYPE_GLOBAL | TAG_GLOBAL_LOGICALMAX):
				CurrStateTable->Attributes.Logical.Maximum  = ReportItemData;
				break;
			case (TYPE_GLOBAL | TAG_GLOBAL_PHYSMIN):
				CurrStateTable->Attributes.Physical.Minimum = ReportItemData;
				break;
			case (TYPE_GLOBAL | TAG_GLOBAL_PHYSMAX):
				CurrStateTable->Attributes.Physical.Maximum = ReportItemData;
				break;
			case (TYPE_GLOBAL | TAG_GLOBAL_UNITEXP):
				CurrStateTable->Attributes.Unit.Exponent    = ReportItemData;
				break;
			case (TYPE_GLOBAL | TAG_GLOBAL_UNIT):
				CurrStateTable->Attributes.Unit.Type        = ReportItemData;
				break;
			case (TYPE_GLOBAL | TAG_GLOBAL_REPORTSIZE):
				CurrStateTable->Attributes.BitSize          = ReportItemData;
				break;
			case (TYPE_GLOBAL | TAG_GLOBAL_REPORTCOUNT):
				CurrStateTable->ReportCount                 = ReportItemData;
				break;
			case (TYPE_GLOBAL | TAG_GLOBAL_REPORTID):
				CurrStateTable->ReportID                    = ReportItemData;
				break;
			case (TYPE_LOCAL | TAG_LOCAL_USAGE):
				if (UsageStackSize == HID_USAGE_STACK_DEPTH)
				  return HID_PARSE_UsageStackOverflow;
			
				UsageStack[UsageStackSize++] = ReportItemData;
				break;
			case (TYPE_LOCAL | TAG_LOCAL_USAGEMIN):
				CurrStateTable->Attributes.Usage.MinMax.Minimum = ReportItemData;
				break;
			case (TYPE_LOCAL | TAG_LOCAL_USAGEMAX):
				CurrStateTable->Attributes.Usage.MinMax.Maximum = ReportItemData;
				break;
			case (TYPE_MAIN | TAG_MAIN_COLLECTION):
				if (CurrCollectionPath == NULL)
				{
					CurrCollectionPath = &ParserData->CollectionPaths[0];
				}
				else
				{
					HID_CollectionPath_t* ParentCollectionPath = CurrCollectionPath;
			
					CurrCollectionPath = &ParserData->CollectionPaths[1];

					while (CurrCollectionPath->Parent != NULL);
					{
						if (CurrCollectionPath == &ParserData->CollectionPaths[HID_MAX_COLLECTIONS])
						  return HID_PARSE_InsufficientCollectionPaths;
					
						CurrCollectionPath++;
					}

					CurrCollectionPath->Parent = ParentCollectionPath;
				}
				
				CurrCollectionPath->Type = ReportItemData;
				CurrCollectionPath->Usage.Page = CurrStateTable->Attributes.Usage.Page;
				
				if (UsageStackSize)
				{
					CurrCollectionPath->Usage.Usage = UsageStack[0];

					for (uint8_t i = 0; i < UsageStackSize; i++)
					  UsageStack[i] = UsageStack[i + 1];
					  
					UsageStackSize--;
				}
				else
				{
					CurrCollectionPath->Usage.Usage = 0;
				}
				
				break;
			case (TYPE_MAIN | TAG_MAIN_ENDCOLLECTION):
				if (CurrCollectionPath == NULL)
				  return HID_PARSE_UnexpectedEndCollection;
		
				CurrCollectionPath = CurrCollectionPath->Parent;

				break;
			case (TYPE_MAIN | TAG_MAIN_INPUT):
			case (TYPE_MAIN | TAG_MAIN_OUTPUT):
#if defined(HID_ENABLE_FEATURE_PROCESSING)
			case (TYPE_MAIN | TAG_MAIN_FEATURE):
#endif
				for (uint8_t ReportItemNum = 0; ReportItemNum < CurrStateTable->ReportCount; ReportItemNum++)
				{
					HID_ReportItem_t* CurrReportItem = &ParserData->ReportItems[ParserData->TotalReportItems];
				
					if (ParserData->TotalReportItems == HID_MAX_REPORTITEMS)
					  return HID_PARSE_InsufficientReportItems;
				  
					memcpy(&CurrReportItem->Attributes,
					       &CurrStateTable->Attributes,
					       sizeof(HID_ReportItem_Attributes_t));

					CurrReportItem->ItemFlags      = ReportItemData;
					CurrReportItem->CollectionPath = CurrCollectionPath;
					CurrReportItem->ReportID       = CurrStateTable->ReportID;

					if (UsageStackSize)
					{
						CurrReportItem->Attributes.Usage.Usage = UsageStack[0];

						for (uint8_t i = 0; i < UsageStackSize; i++)
						  UsageStack[i] = UsageStack[i + 1];
						  
						UsageStackSize--;
					}
					else
					{
						CurrReportItem->Attributes.Usage.Usage = 0;
					}
											
					switch (*ReportData & TAG_MASK)
					{
						case TAG_MAIN_INPUT:
							CurrReportItem->ItemType  = REPORT_ITEM_TYPE_In;
							CurrReportItem->BitOffset = BitOffsetIn;
								
							BitOffsetIn += CurrStateTable->Attributes.BitSize;
							
							break;
						case TAG_MAIN_OUTPUT:
							CurrReportItem->ItemType  = REPORT_ITEM_TYPE_Out;
							CurrReportItem->BitOffset = BitOffsetOut;
								
							BitOffsetOut += CurrStateTable->Attributes.BitSize;
							
							break;
#if defined(HID_ENABLE_FEATURE_PROCESSING)
						case TAG_MAIN_FEATURE:
							CurrReportItem->ItemType  = REPORT_ITEM_TYPE_Feature;						
							CurrReportItem->BitOffset = BitOffsetFeature;
								
							BitOffsetFeature += CurrStateTable->Attributes.BitSize;		

							break;
#endif
					}
					
#if !defined(HID_INCLUDE_CONSTANT_DATA_ITEMS)
					if (!(ReportItemData & IOF_CONSTANT))
					  ParserData->TotalReportItems++;
#else
					ParserData->TotalReportItems++;
#endif
				}
				
				UsageStackSize = 0;
				
				break;
		}
	  
		if ((*ReportData & TYPE_MASK) == TYPE_MAIN)
		{
			CurrStateTable->Attributes.Usage.MinMax.Minimum = 0;
			CurrStateTable->Attributes.Usage.MinMax.Maximum = 0;
			UsageStackSize = 0;
		}
		
		switch (*ReportData & DATA_SIZE_MASK)
		{
			case DATA_SIZE_4:
				ReportSize -= 5;
				ReportData += 5;
				break;
			case DATA_SIZE_2:
				ReportSize -= 3;
				ReportData += 3;
				break;
			case DATA_SIZE_1:
				ReportSize -= 2;
				ReportData += 2;
				break;
			case DATA_SIZE_0:
				ReportSize -= 1;
				ReportData += 1;
				break;
		}
	}
	
	return HID_PARSE_Successful;
}

bool GetReportItemInfo(const uint8_t* ReportData, HID_ReportItem_t* const ReportItem)
{
	uint16_t DataBitsRem  = ReportItem->Attributes.BitSize;
	uint16_t CurrentBit   = ReportItem->BitOffset;
	uint32_t BitMask      = (1 << 0);

	ReportItem->Value = 0;
	
	if (ReportItem->ReportID)
	{
		if (ReportItem->ReportID != ReportData[0])
		  return false;

		ReportData++;
	}

	while (DataBitsRem--)
	{
		if (ReportData[CurrentBit / 8] & (1 << (CurrentBit % 8)))
		  ReportItem->Value |= BitMask;
		
		CurrentBit++;
		BitMask <<= 1;
	}
	
	return true;
}

void SetReportItemInfo(uint8_t* ReportData, const HID_ReportItem_t* ReportItem)
{
	uint16_t DataBitsRem  = ReportItem->Attributes.BitSize;
	uint16_t CurrentBit   = ReportItem->BitOffset;
	uint32_t BitMask      = (1 << 0);

	if (ReportItem->ReportID)
	{
		ReportData[0] = ReportItem->ReportID;
		ReportData++;
	}

	while (DataBitsRem--)
	{
		if (ReportItem->Value & (1 << (CurrentBit % 8)))
		  ReportData[CurrentBit / 8] |= BitMask;

		CurrentBit++;
		BitMask <<= 1;
	}
}