Add user-filtering to the HID report parser, so that the user code can decide which items are to be stored into the HID_ReportInfo_t structure and which should be discarded to save on RAM usage.

This commit is contained in:
Dean Camera 2009-09-02 07:16:52 +00:00
parent ecf7c18cf2
commit 205b35d131
9 changed files with 107 additions and 65 deletions

View file

@ -35,16 +35,14 @@
uint8_t USB_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_StateTable_t StateTable[HID_STATETABLE_STACK_DEPTH];
HID_StateTable_t* CurrStateTable = &StateTable[0];
HID_CollectionPath_t* CurrCollectionPath = NULL;
uint16_t UsageStack[HID_USAGE_STACK_DEPTH];
uint8_t UsageStackSize = 0;
uint16_t BitOffsetIn = 0;
uint16_t BitOffsetOut = 0;
uint16_t BitOffsetFeature = 0;
ParserData->TotalReportItems = 0;
ParserData->UsingMultipleReports = false;
@ -131,10 +129,7 @@ uint8_t USB_ProcessHIDReport(const uint8_t* ReportData, uint16_t ReportSize, HID
ParserData->UsingMultipleReports = true;
BitOffsetIn = 0;
BitOffsetOut = 0;
#if defined(HID_ENABLE_FEATURE_PROCESSING)
BitOffsetFeature = 0;
#endif
break;
case (TYPE_LOCAL | TAG_LOCAL_USAGE):
if (UsageStackSize == HID_USAGE_STACK_DEPTH)
@ -197,27 +192,22 @@ uint8_t USB_ProcessHIDReport(const uint8_t* ReportData, uint16_t ReportSize, HID
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;
HID_ReportItem_t NewReportItem;
memcpy(&CurrReportItem->Attributes,
memcpy(&NewReportItem.Attributes,
&CurrStateTable->Attributes,
sizeof(HID_ReportItem_Attributes_t));
CurrReportItem->ItemFlags = ReportItemData;
CurrReportItem->CollectionPath = CurrCollectionPath;
CurrReportItem->ReportID = CurrStateTable->ReportID;
NewReportItem.ItemFlags = ReportItemData;
NewReportItem.CollectionPath = CurrCollectionPath;
NewReportItem.ReportID = CurrStateTable->ReportID;
if (UsageStackSize)
{
CurrReportItem->Attributes.Usage.Usage = UsageStack[0];
NewReportItem.Attributes.Usage.Usage = UsageStack[0];
for (uint8_t i = 0; i < UsageStackSize; i++)
UsageStack[i] = UsageStack[i + 1];
@ -226,42 +216,41 @@ uint8_t USB_ProcessHIDReport(const uint8_t* ReportData, uint16_t ReportSize, HID
}
else
{
CurrReportItem->Attributes.Usage.Usage = 0;
NewReportItem.Attributes.Usage.Usage = 0;
}
switch (HIDReportItem & TAG_MASK)
{
case TAG_MAIN_INPUT:
CurrReportItem->ItemType = REPORT_ITEM_TYPE_In;
CurrReportItem->BitOffset = BitOffsetIn;
NewReportItem.ItemType = REPORT_ITEM_TYPE_In;
NewReportItem.BitOffset = BitOffsetIn;
BitOffsetIn += CurrStateTable->Attributes.BitSize;
break;
case TAG_MAIN_OUTPUT:
CurrReportItem->ItemType = REPORT_ITEM_TYPE_Out;
CurrReportItem->BitOffset = BitOffsetOut;
NewReportItem.ItemType = REPORT_ITEM_TYPE_Out;
NewReportItem.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;
NewReportItem.ItemType = REPORT_ITEM_TYPE_Feature;
NewReportItem.BitOffset = BitOffsetFeature;
BitOffsetFeature += CurrStateTable->Attributes.BitSize;
BitOffsetFeature += CurrStateTable->Attributes.BitSize;
break;
#endif
}
if (!(ReportItemData & IOF_CONSTANT) && CALLBACK_HIDParser_FilterHIDReportItem(&CurrStateTable->Attributes))
{
if (ParserData->TotalReportItems == HID_MAX_REPORTITEMS)
return HID_PARSE_InsufficientReportItems;
#if defined(HID_INCLUDE_CONSTANT_DATA_ITEMS)
ParserData->TotalReportItems++;
#else
if (!(ReportItemData & IOF_CONSTANT))
ParserData->TotalReportItems++;
#endif
memcpy(&ParserData->ReportItems[ParserData->TotalReportItems],
&NewReportItem, sizeof(HID_ReportItem_t));
ParserData->TotalReportItems++;
}
}
UsageStackSize = 0;

View file

@ -46,16 +46,11 @@
* Functions, macros, variables, enums and types related to the parsing of HID class device report descriptors.
*
* The processed HID report is presented back to the user application as a flat structure containing each report
* item's IN, OUT and FEATURE (if desired) items along with each item's attributes.
* item's IN, OUT and FEATURE items along with each item's attributes.
*
* This library portion also allows for easy setting and retrieval of data from a HID report, including devices
* with multiple reports on the one HID interface.
*
* By default, FEATURE reports and IN/OUT reports with constant data are ignored in the HID report when processed
* to save on memory. This can be overridden by defining the HID_ENABLE_FEATURE_PROCESSING or
* HID_INCLUDE_CONSTANT_DATA_ITEMS tokens in the user project makefile, passing them to the compiler via the -D
* switch.
*
* @{
*/
@ -108,13 +103,13 @@
#endif
#if !defined(HID_MAX_REPORTITEMS) || defined(__DOXYGEN__)
/** Constant indicating the maximum number of report items (IN, OUT or FEATURE if enabled) that can be
* processed in the report item descriptor. A large value allows for more report items to be
* processed, but consumes more memory. By default this is set to 30 items, but this can be
* overridden by defining HID_MAX_REPORTITEMS to another value in the user project makefile, passing
* the define to the compiler using the -D compiler switch.
/** Constant indicating the maximum number of report items (IN, OUT or FEATURE) that can be processed
* in the report item descriptor and stored in the user HID Report Info structure. A large value allows
* for more report items to be stored, but consumes more memory. By default this is set to 20 items,
* but this can be overridden by defining HID_MAX_REPORTITEMS to another value in the user project
* makefile, passing the define to the compiler using the -D compiler switch.
*/
#define HID_MAX_REPORTITEMS 30
#define HID_MAX_REPORTITEMS 20
#endif
/* Public Interface - May be used in end-application: */
@ -250,6 +245,17 @@
*/
void USB_SetHIDReportItemInfo(uint8_t* ReportData, const HID_ReportItem_t* ReportItem)
ATTR_NON_NULL_PTR_ARG(1, 2);
/** Callback routine for the HID Report Parser. This callback <b>must</b> be implemented by the user code when
* the parser is used, to determine what report IN, OUT and FEATURE item's information is stored into the user
* HID_ReportInfo_t structure. This can be used to filter only those items the application will be using, so that
* no RAM is wasted storing the attributes for report items which will never be referenced by the application.
*
* \param CurrentItemAttributes Pointer to the current report item attributes for user checking
*
* \return Boolean true if the item should be stored into the HID_ReportInfo_t structure, false if it should be ignored
*/
bool CALLBACK_HIDParser_FilterHIDReportItem(HID_ReportItem_Attributes_t* CurrentItemAttributes);
/* Private Interface - For use in library only: */
#if !defined(__DOXYGEN__)