3 Copyright (C) Dean Camera, 2014.
5 dean [at] fourwalledcubicle [dot] com
10 Copyright 2014 Dean Camera (dean [at] fourwalledcubicle [dot] com)
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32 * \brief USB Human Interface Device (HID) Class report descriptor parser.
34 * This file allows for the easy parsing of complex HID report descriptors, which describes the data that
35 * a HID device transmits to the host. It also provides an easy API for extracting and processing the data
36 * elements inside a HID report sent from an attached HID device.
39 /** \ingroup Group_USB
40 * \defgroup Group_HIDParser HID Report Parser
41 * \brief USB Human Interface Device (HID) Class report descriptor parser.
43 * \section Sec_HIDParser_Dependencies Module Source Dependencies
44 * The following files must be built with any user project that uses this module:
45 * - LUFA/Drivers/USB/Class/Host/HIDParser.c <i>(Makefile source module name: LUFA_SRC_USB)</i>
47 * \section Sec_HIDParser_ModDescription Module Description
48 * Human Interface Device (HID) class report descriptor parser. This module implements a parser than is
49 * capable of processing a complete HID report descriptor, and outputting a flat structure containing the
50 * contents of the report in an a more friendly format. The parsed data may then be further processed and used
51 * within an application to process sent and received HID reports to and from an attached HID device.
53 * A HID report descriptor consists of a set of HID report items, which describe the function and layout
54 * of data exchanged between a HID device and a host, including both the physical encoding of each item
55 * (such as a button, key press or joystick axis) in the sent and received data packets - known as "reports" -
56 * as well as other information about each item such as the usages, data range, physical location and other
57 * characteristics. In this way a HID device can retain a high degree of flexibility in its capabilities, as it
58 * is not forced to comply with a given report layout or feature-set.
60 * This module also contains routines for the processing of data in an actual HID report, using the parsed report
61 * descriptor data as a guide for the encoding.
66 #ifndef __HIDPARSER_H__
67 #define __HIDPARSER_H__
70 #include "../../../../Common/Common.h"
72 #include "HIDReportData.h"
73 #include "HIDClassCommon.h"
75 /* Enable C linkage for C++ Compilers: */
76 #if defined(__cplusplus)
81 #if !defined(HID_STATETABLE_STACK_DEPTH) || defined(__DOXYGEN__)
82 /** Constant indicating the maximum stack depth of the state table. A larger state table
83 * allows for more PUSH/POP report items to be nested, but consumes more memory. By default
84 * this is set to 2 levels (allowing non-nested PUSH items) but this can be overridden by
85 * defining \c HID_STATETABLE_STACK_DEPTH to another value in the user project makefile, passing the
86 * define to the compiler using the -D compiler switch.
88 #define HID_STATETABLE_STACK_DEPTH 2
91 #if !defined(HID_USAGE_STACK_DEPTH) || defined(__DOXYGEN__)
92 /** Constant indicating the maximum stack depth of the usage table. A larger usage table
93 * allows for more USAGE items to be indicated sequentially for REPORT COUNT entries of more than
94 * one, but requires more stack space. By default this is set to 8 levels (allowing for a report
95 * item with a count of 8) but this can be overridden by defining \c HID_USAGE_STACK_DEPTH to another
96 * value in the user project makefile, passing the define to the compiler using the -D compiler
99 #define HID_USAGE_STACK_DEPTH 8
102 #if !defined(HID_MAX_COLLECTIONS) || defined(__DOXYGEN__)
103 /** Constant indicating the maximum number of COLLECTION items (nested or unnested) that can be
104 * processed in the report item descriptor. A large value allows for more COLLECTION items to be
105 * processed, but consumes more memory. By default this is set to 10 collections, but this can be
106 * overridden by defining \c HID_MAX_COLLECTIONS to another value in the user project makefile, passing
107 * the define to the compiler using the -D compiler switch.
109 #define HID_MAX_COLLECTIONS 10
112 #if !defined(HID_MAX_REPORTITEMS) || defined(__DOXYGEN__)
113 /** Constant indicating the maximum number of report items (IN, OUT or FEATURE) that can be processed
114 * in the report item descriptor and stored in the user HID Report Info structure. A large value allows
115 * for more report items to be stored, but consumes more memory. By default this is set to 20 items,
116 * but this can be overridden by defining \c HID_MAX_REPORTITEMS to another value in the user project
117 * makefile, and passing the define to the compiler using the -D compiler switch.
119 #define HID_MAX_REPORTITEMS 20
122 #if !defined(HID_MAX_REPORT_IDS) || defined(__DOXYGEN__)
123 /** Constant indicating the maximum number of unique report IDs that can be processed in the report item
124 * descriptor for the report size information array in the user HID Report Info structure. A large value
125 * allows for more report ID report sizes to be stored, but consumes more memory. By default this is set
126 * to 10 items, but this can be overridden by defining \c HID_MAX_REPORT_IDS to another value in the user project
127 * makefile, and passing the define to the compiler using the -D compiler switch. Note that IN, OUT and FEATURE
128 * items sharing the same report ID consume only one size item in the array.
130 #define HID_MAX_REPORT_IDS 10
133 /** Returns the value a given HID report item (once its value has been fetched via \ref USB_GetHIDReportItemInfo())
134 * left-aligned to the given data type. This allows for signed data to be interpreted correctly, by shifting the data
135 * leftwards until the data's sign bit is in the correct position.
137 * \param[in] ReportItem HID Report Item whose retrieved value is to be aligned.
138 * \param[in] Type Data type to align the HID report item's value to.
140 * \return Left-aligned data of the given report item's pre-retrieved value for the given datatype.
142 #define HID_ALIGN_DATA(ReportItem, Type) ((Type)(ReportItem->Value << ((8 * sizeof(Type)) - ReportItem->Attributes.BitSize)))
144 /* Public Interface - May be used in end-application: */
146 /** Enum for the possible error codes in the return value of the \ref USB_ProcessHIDReport() function. */
147 enum HID_Parse_ErrorCodes_t
149 HID_PARSE_Successful = 0, /**< Successful parse of the HID report descriptor, no error. */
150 HID_PARSE_HIDStackOverflow = 1, /**< More than \ref HID_STATETABLE_STACK_DEPTH nested PUSHes in the report. */
151 HID_PARSE_HIDStackUnderflow = 2, /**< A POP was found when the state table stack was empty. */
152 HID_PARSE_InsufficientReportItems = 3, /**< More than \ref HID_MAX_REPORTITEMS report items in the report. */
153 HID_PARSE_UnexpectedEndCollection = 4, /**< An END COLLECTION item found without matching COLLECTION item. */
154 HID_PARSE_InsufficientCollectionPaths = 5, /**< More than \ref HID_MAX_COLLECTIONS collections in the report. */
155 HID_PARSE_UsageListOverflow = 6, /**< More than \ref HID_USAGE_STACK_DEPTH usages listed in a row. */
156 HID_PARSE_InsufficientReportIDItems = 7, /**< More than \ref HID_MAX_REPORT_IDS report IDs in the device. */
157 HID_PARSE_NoUnfilteredReportItems = 8, /**< All report items from the device were filtered by the filtering callback routine. */
161 /** \brief HID Parser Report Item Min/Max Structure.
163 * Type define for an attribute with both minimum and maximum values (e.g. Logical Min/Max).
167 uint32_t Minimum; /**< Minimum value for the attribute. */
168 uint32_t Maximum; /**< Maximum value for the attribute. */
171 /** \brief HID Parser Report Item Unit Structure.
173 * Type define for the Unit attributes of a report item.
177 uint32_t Type; /**< Unit type (refer to HID specifications for details). */
178 uint8_t Exponent; /**< Unit exponent (refer to HID specifications for details). */
181 /** \brief HID Parser Report Item Usage Structure.
183 * Type define for the Usage attributes of a report item.
187 uint16_t Page; /**< Usage page of the report item. */
188 uint16_t Usage; /**< Usage of the report item. */
191 /** \brief HID Parser Report Item Collection Path Structure.
193 * Type define for a COLLECTION object. Contains the collection attributes and a reference to the
194 * parent collection if any.
196 typedef struct HID_CollectionPath
198 uint8_t Type; /**< Collection type (e.g. "Generic Desktop"). */
199 HID_Usage_t Usage; /**< Collection usage. */
200 struct HID_CollectionPath* Parent; /**< Reference to parent collection, or \c NULL if root collection. */
201 } HID_CollectionPath_t;
203 /** \brief HID Parser Report Item Attributes Structure.
205 * Type define for all the data attributes of a report item, except flags.
209 uint8_t BitSize; /**< Size in bits of the report item's data. */
211 HID_Usage_t Usage; /**< Usage of the report item. */
212 HID_Unit_t Unit; /**< Unit type and exponent of the report item. */
213 HID_MinMax_t Logical; /**< Logical minimum and maximum of the report item. */
214 HID_MinMax_t Physical; /**< Physical minimum and maximum of the report item. */
215 } HID_ReportItem_Attributes_t;
217 /** \brief HID Parser Report Item Details Structure.
219 * Type define for a report item (IN, OUT or FEATURE) layout attributes and other details.
223 uint16_t BitOffset; /**< Bit offset in the IN, OUT or FEATURE report of the item. */
224 uint8_t ItemType; /**< Report item type, a value in \ref HID_ReportItemTypes_t. */
225 uint16_t ItemFlags; /**< Item data flags, a mask of \c HID_IOF_* constants. */
226 uint8_t ReportID; /**< Report ID this item belongs to, or 0x00 if device has only one report */
227 HID_CollectionPath_t* CollectionPath; /**< Collection path of the item. */
229 HID_ReportItem_Attributes_t Attributes; /**< Report item attributes. */
231 uint32_t Value; /**< Current value of the report item - use \ref HID_ALIGN_DATA() when processing
232 * a retrieved value so that it is aligned to a specific type.
234 uint32_t PreviousValue; /**< Previous value of the report item. */
237 /** \brief HID Parser Report Size Structure.
239 * Type define for a report item size information structure, to retain the size of a device's reports by ID.
243 uint8_t ReportID; /**< Report ID of the report within the HID interface. */
244 uint16_t ReportSizeBits[3]; /**< Total number of bits in each report type for the given Report ID,
245 * indexed by the \ref HID_ReportItemTypes_t enum.
247 } HID_ReportSizeInfo_t;
249 /** \brief HID Parser State Structure.
251 * Type define for a complete processed HID report, including all report item data and collections.
255 uint8_t TotalReportItems; /**< Total number of report items stored in the \c ReportItems array. */
256 HID_ReportItem_t ReportItems[HID_MAX_REPORTITEMS]; /**< Report items array, including all IN, OUT
259 HID_CollectionPath_t CollectionPaths[HID_MAX_COLLECTIONS]; /**< All collection items, referenced
260 * by the report items.
262 uint8_t TotalDeviceReports; /**< Number of reports within the HID interface */
263 HID_ReportSizeInfo_t ReportIDSizes[HID_MAX_REPORT_IDS]; /**< Report sizes for each report in the interface */
264 uint16_t LargestReportSizeBits; /**< Largest report that the attached device will generate, in bits */
265 bool UsingReportIDs; /**< Indicates if the device has at least one REPORT ID
266 * element in its HID report descriptor.
270 /* Function Prototypes: */
271 /** Function to process a given HID report returned from an attached device, and store it into a given
272 * \ref HID_ReportInfo_t structure.
274 * \param[in] ReportData Buffer containing the device's HID report table.
275 * \param[in] ReportSize Size in bytes of the HID report table.
276 * \param[out] ParserData Pointer to a \ref HID_ReportInfo_t instance for the parser output.
278 * \return A value in the \ref HID_Parse_ErrorCodes_t enum.
280 uint8_t USB_ProcessHIDReport(const uint8_t* ReportData,
282 HID_ReportInfo_t* const ParserData) ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(3);
284 /** Extracts the given report item's value out of the given HID report and places it into the Value
285 * member of the report item's \ref HID_ReportItem_t structure.
287 * When called on a report with an item that exists in that report, this copies the report item's \c Value
288 * to its \c PreviousValue element for easy checking to see if an item's value has changed before processing
289 * a report. If the given item does not exist in the report, the function does not modify the report item's
292 * \param[in] ReportData Buffer containing an IN or FEATURE report from an attached device.
293 * \param[in,out] ReportItem Pointer to the report item of interest in a \ref HID_ReportInfo_t ReportItem array.
295 * \returns Boolean \c true if the item to retrieve was located in the given report, \c false otherwise.
297 bool USB_GetHIDReportItemInfo(const uint8_t* ReportData,
298 HID_ReportItem_t* const ReportItem) ATTR_NON_NULL_PTR_ARG(1);
300 /** Retrieves the given report item's value out of the \c Value member of the report item's
301 * \ref HID_ReportItem_t structure and places it into the correct position in the HID report
302 * buffer. The report buffer is assumed to have the appropriate bits cleared before calling
303 * this function (i.e., the buffer should be explicitly cleared before report values are added).
305 * When called, this copies the report item's \c Value element to its \c PreviousValue element for easy
306 * checking to see if an item's value has changed before sending a report.
308 * If the device has multiple HID reports, the first byte in the report is set to the report ID of the given item.
310 * \param[out] ReportData Buffer holding the current OUT or FEATURE report data.
311 * \param[in] ReportItem Pointer to the report item of interest in a \ref HID_ReportInfo_t ReportItem array.
313 void USB_SetHIDReportItemInfo(uint8_t* ReportData,
314 HID_ReportItem_t* const ReportItem) ATTR_NON_NULL_PTR_ARG(1);
316 /** Retrieves the size of a given HID report in bytes from its Report ID.
318 * \param[in] ParserData Pointer to a \ref HID_ReportInfo_t instance containing the parser output.
319 * \param[in] ReportID Report ID of the report whose size is to be determined.
320 * \param[in] ReportType Type of the report whose size is to be determined, a value from the
321 * \ref HID_ReportItemTypes_t enum.
323 * \return Size of the report in bytes, or \c 0 if the report does not exist.
325 uint16_t USB_GetHIDReportSize(HID_ReportInfo_t* const ParserData,
326 const uint8_t ReportID,
327 const uint8_t ReportType) ATTR_CONST ATTR_NON_NULL_PTR_ARG(1);
329 /** Callback routine for the HID Report Parser. This callback <b>must</b> be implemented by the user code when
330 * the parser is used, to determine what report IN, OUT and FEATURE item's information is stored into the user
331 * \ref HID_ReportInfo_t structure. This can be used to filter only those items the application will be using, so that
332 * no RAM is wasted storing the attributes for report items which will never be referenced by the application.
334 * Report item pointers passed to this callback function may be cached by the user application for later use
335 * when processing report items. This provides faster report processing in the user application than would
336 * a search of the entire parsed report item table for each received or sent report.
338 * \param[in] CurrentItem Pointer to the current report item for user checking.
340 * \return Boolean \c true if the item should be stored into the \ref HID_ReportInfo_t structure, \c false if
341 * it should be ignored.
343 bool CALLBACK_HIDParser_FilterHIDReportItem(HID_ReportItem_t* const CurrentItem);
345 /* Private Interface - For use in library only: */
346 #if !defined(__DOXYGEN__)
350 HID_ReportItem_Attributes_t Attributes;
356 /* Disable C linkage for C++ Compilers: */
357 #if defined(__cplusplus)