Commit 205b35d1 authored by Dean Camera's avatar Dean Camera
Browse files

Add user-filtering to the HID report parser, so that the user code can decide...

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.
parent ecf7c18c
......@@ -70,3 +70,25 @@ uint8_t GetHIDReportData(void)
return ParseSuccessful;
}
/** Callback for the HID Report Parser. This function is called each time the HID report parser is about to store
* an IN, OUT or FEATURE item into the HIDReportInfo structure. To save on RAM, we are able to filter out items
* we aren't interested in (preventing us from being able to extract them later on, but saving on the RAM they would
* have occupied).
*
* \param CurrentItemAttributes Pointer to the attrbutes of the item the HID report parser is currently working with
*
* \return Boolean true if the item should be stored into the HID report structure, false if it should be discarded
*/
bool CALLBACK_HIDParser_FilterHIDReportItem(HID_ReportItem_Attributes_t* CurrentItemAttributes)
{
/* Check the attributes of the current item - see if we are interested in it or not */
if (CurrentItemAttributes->Usage.Page == USAGE_PAGE_KEYBOARD)
{
/* Only store KEYBOARD usage page items into the Processed HID Report structure to save RAM */
return true;
}
else
{
return false;
}
}
......@@ -76,5 +76,7 @@
/* Function Prototypes: */
uint8_t GetHIDReportData(void);
bool CALLBACK_HIDParser_FilterHIDReportItem(HID_ReportItem_Attributes_t* CurrentItemAttributes);
#endif
......@@ -69,3 +69,27 @@ uint8_t GetHIDReportData(void)
return ParseSuccessful;
}
/** Callback for the HID Report Parser. This function is called each time the HID report parser is about to store
* an IN, OUT or FEATURE item into the HIDReportInfo structure. To save on RAM, we are able to filter out items
* we aren't interested in (preventing us from being able to extract them later on, but saving on the RAM they would
* have occupied).
*
* \param CurrentItemAttributes Pointer to the attrbutes of the item the HID report parser is currently working with
*
* \return Boolean true if the item should be stored into the HID report structure, false if it should be discarded
*/
bool CALLBACK_HIDParser_FilterHIDReportItem(HID_ReportItem_Attributes_t* CurrentItemAttributes)
{
/* Check the attributes of the current item - see if we are interested in it or not */
if ((CurrentItemAttributes->Usage.Page == USAGE_PAGE_BUTTON) ||
(CurrentItemAttributes->Usage.Page == USAGE_PAGE_GENERIC_DCTRL))
{
/* Only store BUTTON and GENERIC_DESKTOP_CONTROL items into the Processed HID Report structure to save RAM */
return true;
}
else
{
return false;
}
}
......@@ -86,4 +86,6 @@
/* Function Prototypes: */
uint8_t GetHIDReportData(void);
bool CALLBACK_HIDParser_FilterHIDReportItem(HID_ReportItem_Attributes_t* CurrentItemAttributes);
#endif
......@@ -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;
......
......@@ -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__)
......
......@@ -18,6 +18,8 @@
* - Added ShutDown() functions for all hardware peripheral drivers, so that peripherals can be turned off after use
* - Added new CDC_Device_Flush() command to the device mode CDC Class driver to flush Device->Host data
* - Added extra masks to the SPI driver, changed SPI_Init() so that the clock polarity and sample modes can be set
* - Added new callback to the HID report parser, so that the user application can filter only the items it is interested
* in to be stored into the HIDReportInfo structure to save RAM
*
* <b>Changed:</b>
* - SetIdle requests to the HID device driver with a 0 idle period (send changes only) now only affect the requested
......@@ -32,6 +34,8 @@
* - Changed the parameters and behaviour of the USB_GetDeviceConfigDescriptor() function so that it now performs size checks
* and data validations internally, to simplify user code
* - Changed HIDParser to only zero out important values in the Parsed HID Report Item Information structure to save cycles
* - The HID report parser now always processed FEATURE items - HID_ENABLE_FEATURE_PROCESSING token now has no effect
* - The HID report parser now always ignores constant-data items, HID_INCLUDE_CONSTANT_DATA_ITEMS token now has no effect
*
* <b>Fixed:</b>
* - Fixed possible lockup in the CDC device class driver, when the host sends data that is a multiple of the
......
......@@ -23,17 +23,6 @@
* \section Sec_SummaryUSBClassTokens USB Class Driver Related Tokens
* This section describes compile tokens which affect USB class-specific drivers in the LUFA library.
*
* <b>HID_ENABLE_FEATURE_PROCESSING</b> - ( \ref Group_HIDParser ) \n
* Define this token to enable the processing of FEATURE HID report items, if any, into the processed HID structure.
* By default FEATURE items (which are device features settable by the host but not directly visible by the user) are
* skipped when processing a device HID report.
*
* <b>HID_INCLUDE_CONSTANT_DATA_ITEMS</b> - ( \ref Group_HIDParser ) \n
* By default, constant data items (usually used as spacers to align separate report items to a byte or word boundary)
* in the HID report are skipped during report processing. It is highly unusual for an application to make any use of
* constant data items (as they do not carry any useful data and only occupy limited RAM) however if required defining
* this switch will put constant data items into the processed HID report structure.
*
* <b>HID_STATETABLE_STACK_DEPTH</b> - ( \ref Group_HIDParser ) \n
* HID reports may contain PUSH and POP elements, to store and retrieve the current HID state table onto a stack. This
* allows for reports to save the state table before modifying it slightly for a data item, and then restore the previous
......
......@@ -24,6 +24,10 @@
* preallocate the largest allowable buffer, and pass the size of the buffer to the function. This allows for a single
* call to the function to retrieve, size check and validate the Configuration Descriptor rather than having the user
* application perform these intermediatary steps.
* - The HID report parser now requires a mandatory callback in the user code, to filter only the items the application
* is interested in into the processed HID report item structure to save RAM. See \ref CALLBACK_HIDParser_FilterHIDReportItem().
* - The HID report parser now always parses FEATURE and always ignores constant-data items - the HID_ENABLE_FEATURE_PROCESSING
* and HID_INCLUDE_CONSTANT_DATA_ITEMS compile time tokens now have no effect.
*
* \section Sec_Migration090810 Migrating from 090605 to 090810
*
......
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