LUFA/Drivers/USB/Class/Common/HIDParser.h

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2011.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6            www.lufa-lib.org
   7 */
   8
   9 /*
  10   Copyright 2011  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Permission to use, copy, modify, distribute, and sell this
  13   software and its documentation for any purpose is hereby granted
  14   without fee, provided that the above copyright notice appear in
  15   all copies and that both that the copyright notice and this
  16   permission notice and warranty disclaimer appear in supporting
  17   documentation, and that the name of the author not be used in
  18   advertising or publicity pertaining to distribution of the
  19   software without specific, written prior permission.
  20
  21   The author disclaim all warranties with regard to this
  22   software, including all implied warranties of merchantability
  23   and fitness.  In no event shall the author be liable for any
  24   special, indirect or consequential damages or any damages
  25   whatsoever resulting from loss of use, data or profits, whether
  26   in an action of contract, negligence or other tortious action,
  27   arising out of or in connection with the use or performance of
  28   this software.
  29 */
  30
  31 /** \file
  32  *  \brief USB Human Interface Device (HID) Class report descriptor parser.
  33  *
  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.
  37  */
  38
  39 /** \ingroup Group_USB
  40  *  \defgroup Group_HIDParser HID Report Parser
  41  *
  42  *  \section Sec_Dependencies Module Source Dependencies
  43  *  The following files must be built with any user project that uses this module:
  44  *    - LUFA/Drivers/USB/Class/Host/HIDParser.c <i>(Makefile source module name: LUFA_SRC_USB)</i>
  45  *
  46  *  \section Sec_ModDescription Module Description
  47  *  Human Interface Device (HID) class report descriptor parser. This module implements a parser than is
  48  *  capable of processing a complete HID report descriptor, and outputting a flat structure containing the
  49  *  contents of the report in an a more friendly format. The parsed data may then be further processed and used
  50  *  within an application to process sent and received HID reports to and from an attached HID device.
  51  *
  52  *  A HID report descriptor consists of a set of HID report items, which describe the function and layout
  53  *  of data exchanged between a HID device and a host, including both the physical encoding of each item
  54  *  (such as a button, key press or joystick axis) in the sent and received data packets - known as "reports" -
  55  *  as well as other information about each item such as the usages, data range, physical location and other
  56  *  characterstics. In this way a HID device can retain a high degree of flexibility in its capabilities, as it
  57  *  is not forced to comply with a given report layout or featureset.
  58  *
  59  *  This module also contains routines for the processing of data in an actual HID report, using the parsed report
  60  *  descritor data as a guide for the encoding.
  61  *
  62  *  @{
  63  */
  64
  65 #ifndef __HIDPARSER_H__
  66 #define __HIDPARSER_H__
  67
  68         /* Includes: */
  69                 #include "../../../../Common/Common.h"
  70
  71                 #include "HIDReportData.h"
  72                 #include "../Common/HID.h"
  73
  74                 #include <string.h>
  75
  76         /* Enable C linkage for C++ Compilers: */
  77                 #if defined(__cplusplus)
  78                         extern "C" {
  79                 #endif
  80
  81         /* Macros: */
  82                 #if !defined(HID_STATETABLE_STACK_DEPTH) || defined(__DOXYGEN__)
  83                         /** Constant indicating the maximum stack depth of the state table. A larger state table
  84                          *  allows for more PUSH/POP report items to be nested, but consumes more memory. By default
  85                          *  this is set to 2 levels (allowing non-nested PUSH items) but this can be overridden by
  86                          *  defining \c HID_STATETABLE_STACK_DEPTH to another value in the user project makefile, passing the
  87                          *  define to the compiler using the -D compiler switch.
  88                          */
  89                         #define HID_STATETABLE_STACK_DEPTH    2
  90                 #endif
  91
  92                 #if !defined(HID_USAGE_STACK_DEPTH) || defined(__DOXYGEN__)
  93                         /** Constant indicating the maximum stack depth of the usage table. A larger usage table
  94                          *  allows for more USAGE items to be indicated sequentially for REPORT COUNT entries of more than
  95                          *  one, but requires more stack space. By default this is set to 8 levels (allowing for a report
  96                          *  item with a count of 8) but this can be overridden by defining \c HID_USAGE_STACK_DEPTH to another
  97                          *  value in the user project makefile, passing the define to the compiler using the -D compiler
  98                          *  switch.
  99                          */
 100                         #define HID_USAGE_STACK_DEPTH         8
 101                 #endif
 102
 103                 #if !defined(HID_MAX_COLLECTIONS) || defined(__DOXYGEN__)
 104                         /** Constant indicating the maximum number of COLLECTION items (nested or unnested) that can be
 105                          *  processed in the report item descriptor. A large value allows for more COLLECTION items to be
 106                          *  processed, but consumes more memory. By default this is set to 10 collections, but this can be
 107                          *  overridden by defining \c HID_MAX_COLLECTIONS to another value in the user project makefile, passing
 108                          *  the define to the compiler using the -D compiler switch.
 109                          */
 110                         #define HID_MAX_COLLECTIONS           10
 111                 #endif
 112
 113                 #if !defined(HID_MAX_REPORTITEMS) || defined(__DOXYGEN__)
 114                         /** Constant indicating the maximum number of report items (IN, OUT or FEATURE) that can be processed
 115                          *  in the report item descriptor and stored in the user HID Report Info structure. A large value allows
 116                          *  for more report items to be stored, but consumes more memory. By default this is set to 20 items,
 117                          *  but this can be overridden by defining \c HID_MAX_REPORTITEMS to another value in the user project
 118                          *  makefile, and passing the define to the compiler using the -D compiler switch.
 119                          */
 120                         #define HID_MAX_REPORTITEMS           20
 121                 #endif
 122
 123                 #if !defined(HID_MAX_REPORT_IDS) || defined(__DOXYGEN__)
 124                         /** Constant indicating the maximum number of unique report IDs that can be processed in the report item
 125                          *  descriptor for the report size information array in the user HID Report Info structure. A large value
 126                          *  allows for more report ID report sizes to be stored, but consumes more memory. By default this is set
 127                          *  to 10 items, but this can be overridden by defining \c HID_MAX_REPORT_IDS to another value in the user project
 128                          *  makefile, and passing the define to the compiler using the -D compiler switch. Note that IN, OUT and FEATURE
 129                          *  items sharing the same report ID consume only one size item in the array.
 130                          */
 131                         #define HID_MAX_REPORT_IDS            10
 132                 #endif
 133
 134                 /** Returns the value a given HID report item (once its value has been fetched via \ref USB_GetHIDReportItemInfo())
 135                  *  left-aligned to the given data type. This allows for signed data to be interpreted correctly, by shifting the data
 136                  *  leftwards until the data's sign bit is in the correct position.
 137                  *
 138                  *  \param[in] ReportItem  HID Report Item whose retrieved value is to be aligned.
 139                  *  \param[in] Type        Data type to align the HID report item's value to.
 140                  *
 141                  *  \return Left-aligned data of the given report item's pre-retrieved value for the given datatype.
 142                  */
 143                 #define HID_ALIGN_DATA(ReportItem, Type) ((Type)(ReportItem->Value << ((8 * sizeof(Type)) - ReportItem->Attributes.BitSize)))
 144
 145         /* Public Interface - May be used in end-application: */
 146                 /* Enums: */
 147                         /** Enum for the possible error codes in the return value of the \ref USB_ProcessHIDReport() function. */
 148                         enum HID_Parse_ErrorCodes_t
 149                         {
 150                                 HID_PARSE_Successful                  = 0, /**< Successful parse of the HID report descriptor, no error. */
 151                                 HID_PARSE_HIDStackOverflow            = 1, /**< More than \ref HID_STATETABLE_STACK_DEPTH nested PUSHes in the report. */
 152                                 HID_PARSE_HIDStackUnderflow           = 2, /**< A POP was found when the state table stack was empty. */
 153                                 HID_PARSE_InsufficientReportItems     = 3, /**< More than \ref HID_MAX_REPORTITEMS report items in the report. */
 154                                 HID_PARSE_UnexpectedEndCollection     = 4, /**< An END COLLECTION item found without matching COLLECTION item. */
 155                                 HID_PARSE_InsufficientCollectionPaths = 5, /**< More than \ref HID_MAX_COLLECTIONS collections in the report. */
 156                                 HID_PARSE_UsageListOverflow           = 6, /**< More than \ref HID_USAGE_STACK_DEPTH usages listed in a row. */
 157                                 HID_PARSE_InsufficientReportIDItems   = 7, /**< More than \ref HID_MAX_REPORT_IDS report IDs in the device. */
 158                                 HID_PARSE_NoUnfilteredReportItems     = 8, /**< All report items from the device were filtered by the filtering callback routine. */
 159                         };
 160
 161                 /* Type Defines: */
 162                         /** \brief HID Parser Report Item Min/Max Structure.
 163                          *
 164                          *  Type define for an attribute with both minimum and maximum values (e.g. Logical Min/Max).
 165                          */
 166                         typedef struct
 167                         {
 168                                 uint32_t Minimum; /**< Minimum value for the attribute. */
 169                                 uint32_t Maximum; /**< Maximum value for the attribute. */
 170                         } HID_MinMax_t;
 171
 172                         /** \brief HID Parser Report Item Unit Structure.
 173                          *
 174                          *  Type define for the Unit attributes of a report item.
 175                          */
 176                         typedef struct
 177                         {
 178                                 uint32_t Type;     /**< Unit type (refer to HID specifications for details). */
 179                                 uint8_t  Exponent; /**< Unit exponent (refer to HID specifications for details). */
 180                         } HID_Unit_t;
 181
 182                         /** \brief HID Parser Report Item Usage Structure.
 183                          *
 184                          *  Type define for the Usage attributes of a report item.
 185                          */
 186                         typedef struct
 187                         {
 188                                 uint16_t Page;  /**< Usage page of the report item. */
 189                                 uint16_t Usage; /**< Usage of the report item. */
 190                         } HID_Usage_t;
 191
 192                         /** \brief HID Parser Report Item Collection Path Structure.
 193                          *
 194                          *  Type define for a COLLECTION object. Contains the collection attributes and a reference to the
 195                          *  parent collection if any.
 196                          */
 197                         typedef struct HID_CollectionPath
 198                         {
 199                                 uint8_t                    Type;   /**< Collection type (e.g. "Generic Desktop"). */
 200                                 HID_Usage_t                Usage;  /**< Collection usage. */
 201                                 struct HID_CollectionPath* Parent; /**< Reference to parent collection, or \c NULL if root collection. */
 202                         } HID_CollectionPath_t;
 203
 204                         /** \brief HID Parser Report Item Attributes Structure.
 205                          *
 206                          *  Type define for all the data attributes of a report item, except flags.
 207                          */
 208                         typedef struct
 209                         {
 210                                 uint8_t      BitSize;  /**< Size in bits of the report item's data. */
 211
 212                                 HID_Usage_t  Usage;    /**< Usage of the report item. */
 213                                 HID_Unit_t   Unit;     /**< Unit type and exponent of the report item. */
 214                                 HID_MinMax_t Logical;  /**< Logical minimum and maximum of the report item. */
 215                                 HID_MinMax_t Physical; /**< Physical minimum and maximum of the report item. */
 216                         } HID_ReportItem_Attributes_t;
 217
 218                         /** \brief HID Parser Report Item Details Structure.
 219                          *
 220                          *  Type define for a report item (IN, OUT or FEATURE) layout attributes and other details.
 221                          */
 222                         typedef struct
 223                         {
 224                                 uint16_t                    BitOffset;      /**< Bit offset in the IN, OUT or FEATURE report of the item. */
 225                                 uint8_t                     ItemType;       /**< Report item type, a value in \ref HID_ReportItemTypes_t. */
 226                                 uint16_t                    ItemFlags;      /**< Item data flags, a mask of HID_IOF_* constants. */
 227                                 uint8_t                     ReportID;       /**< Report ID this item belongs to, or 0x00 if device has only one report */
 228                                 HID_CollectionPath_t*       CollectionPath; /**< Collection path of the item. */
 229
 230                                 HID_ReportItem_Attributes_t Attributes;     /**< Report item attributes. */
 231
 232                                 uint32_t                    Value;          /**< Current value of the report item - use \ref HID_ALIGN_DATA() when processing
 233                                                                              *   a retrieved value so that it is aligned to a specific type.
 234                                                                              */
 235                                 uint32_t                    PreviousValue;  /**< Previous value of the report item. */
 236                         } HID_ReportItem_t;
 237
 238                         /** \brief HID Parser Report Size Structure.
 239                          *
 240                          *  Type define for a report item size information structure, to retain the size of a device's reports by ID.
 241                          */
 242                         typedef struct
 243                         {
 244                                 uint8_t  ReportID; /**< Report ID of the report within the HID interface. */
 245                                 uint16_t ReportSizeBits[3]; /**< Total number of bits in each report type for the given Report ID,
 246                                                              *   indexed by the \ref HID_ReportItemTypes_t enum.
 247                                                              */
 248                         } HID_ReportSizeInfo_t;
 249
 250                         /** \brief HID Parser State Structure.
 251                          *
 252                          *  Type define for a complete processed HID report, including all report item data and collections.
 253                          */
 254                         typedef struct
 255                         {
 256                                 uint8_t              TotalReportItems; /**< Total number of report items stored in the \c ReportItems array. */
 257                                 HID_ReportItem_t     ReportItems[HID_MAX_REPORTITEMS]; /**< Report items array, including all IN, OUT
 258                                                                                     *   and FEATURE items.
 259                                                                                         */
 260                                 HID_CollectionPath_t CollectionPaths[HID_MAX_COLLECTIONS]; /**< All collection items, referenced
 261                                                                                             *   by the report items.
 262                                                                                             */
 263                                 uint8_t              TotalDeviceReports; /**< Number of reports within the HID interface */
 264                                 HID_ReportSizeInfo_t ReportIDSizes[HID_MAX_REPORT_IDS]; /**< Report sizes for each report in the interface */
 265                                 uint16_t             LargestReportSizeBits; /**< Largest report that the attached device will generate, in bits */
 266                                 bool                 UsingReportIDs; /**< Indicates if the device has at least one REPORT ID
 267                                                                       *   element in its HID report descriptor.
 268                                                                       */
 269                         } HID_ReportInfo_t;
 270
 271                 /* Function Prototypes: */
 272                         /** Function to process a given HID report returned from an attached device, and store it into a given
 273                          *  \ref HID_ReportInfo_t structure.
 274                          *
 275                          *  \param[in]  ReportData  Buffer containing the device's HID report table.
 276                          *  \param[in]  ReportSize  Size in bytes of the HID report table.
 277                          *  \param[out] ParserData  Pointer to a \ref HID_ReportInfo_t instance for the parser output.
 278                          *
 279                          *  \return A value in the \ref HID_Parse_ErrorCodes_t enum.
 280                          */
 281                         uint8_t USB_ProcessHIDReport(const uint8_t* ReportData,
 282                                                      uint16_t ReportSize,
 283                                                      HID_ReportInfo_t* const ParserData) ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(3);
 284
 285                         /** Extracts the given report item's value out of the given HID report and places it into the Value
 286                          *  member of the report item's \ref HID_ReportItem_t structure.
 287                          *
 288                          *  When called on a report with an item that exists in that report, this copies the report item's Value
 289                          *  to it's PreviousValue element for easy checking to see if an item's value has changed before processing
 290                          *  a report. If the given item does not exist in the report, the function does not modify the report item's
 291                          *  data.
 292                          *
 293                          *  \param[in]     ReportData  Buffer containing an IN or FEATURE report from an attached device.
 294                          *  \param[in,out] ReportItem  Pointer to the report item of interest in a \ref HID_ReportInfo_t ReportItem array.
 295                          *
 296                          *  \returns Boolean \c true if the item to retrieve was located in the given report, \c false otherwise.
 297                          */
 298                         bool USB_GetHIDReportItemInfo(const uint8_t* ReportData,
 299                                                       HID_ReportItem_t* const ReportItem) ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 300
 301                         /** Retrieves the given report item's value out of the Value member of the report item's
 302                          *  \ref HID_ReportItem_t structure and places it into the correct position in the HID report
 303                          *  buffer. The report buffer is assumed to have the appropriate bits cleared before calling
 304                          *  this function (i.e., the buffer should be explicitly cleared before report values are added).
 305                          *
 306                          *  When called, this copies the report item's Value element to it's PreviousValue element for easy
 307                          *  checking to see if an item's value has changed before sending a report.
 308                          *
 309                          *  If the device has multiple HID reports, the first byte in the report is set to the report ID of the given item.
 310                          *
 311                          *  \param[out] ReportData  Buffer holding the current OUT or FEATURE report data.
 312                          *  \param[in]  ReportItem  Pointer to the report item of interest in a \ref HID_ReportInfo_t ReportItem array.
 313                          */
 314                         void USB_SetHIDReportItemInfo(uint8_t* ReportData,
 315                                                       HID_ReportItem_t* const ReportItem) ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 316
 317                         /** Retrieves the size of a given HID report in bytes from it's Report ID.
 318                          *
 319                          *  \param[in] ParserData  Pointer to a \ref HID_ReportInfo_t instance containing the parser output.
 320                          *  \param[in] ReportID    Report ID of the report whose size is to be retrieved.
 321                          *  \param[in] ReportType  Type of the report whose size is to be determined, a valued from the
 322                          *                         \ref HID_ReportItemTypes_t enum.
 323                          *
 324                          *  \return Size of the report in bytes, or 0 if the report does not exist.
 325                          */
 326                         uint16_t USB_GetHIDReportSize(HID_ReportInfo_t* const ParserData,
 327                                                       const uint8_t ReportID,
 328                                                       const uint8_t ReportType) ATTR_CONST ATTR_NON_NULL_PTR_ARG(1);
 329
 330                         /** Callback routine for the HID Report Parser. This callback <b>must</b> be implemented by the user code when
 331                          *  the parser is used, to determine what report IN, OUT and FEATURE item's information is stored into the user
 332                          *  \ref HID_ReportInfo_t structure. This can be used to filter only those items the application will be using, so that
 333                          *  no RAM is wasted storing the attributes for report items which will never be referenced by the application.
 334                          *
 335                          *  \param[in] CurrentItem  Pointer to the current report item for user checking.
 336                          *
 337                          *  \return Boolean \c true if the item should be stored into the \ref HID_ReportInfo_t structure, \c false if
 338                          *          it should be ignored.
 339                          */
 340                         bool CALLBACK_HIDParser_FilterHIDReportItem(HID_ReportItem_t* const CurrentItem);
 341
 342         /* Private Interface - For use in library only: */
 343         #if !defined(__DOXYGEN__)
 344                 /* Type Defines: */
 345                         typedef struct
 346                         {
 347                                  HID_ReportItem_Attributes_t Attributes;
 348                                  uint8_t                     ReportCount;
 349                                  uint8_t                     ReportID;
 350                         } HID_StateTable_t;
 351         #endif
 352
 353         /* Disable C linkage for C++ Compilers: */
 354                 #if defined(__cplusplus)
 355                         }
 356                 #endif
 357
 358 #endif
 359
 360 /** @} */
 361