LUFA/Drivers/USB/Class/Host/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  *  Functions, macros, variables, enums and types related to the parsing of HID class device report descriptors.
  48  *
  49  *  The processed HID report is presented back to the user application as a flat structure containing each report
  50  *  item's IN, OUT and FEATURE items along with each item's attributes.
  51  *
  52  *  This library portion also allows for easy setting and retrieval of data from a HID report, including devices
  53  *  with multiple reports on the one HID interface.
  54  *
  55  *  @{
  56  */
  57
  58 #ifndef __HIDPARSER_H__
  59 #define __HIDPARSER_H__
  60
  61         /* Includes: */
  62                 #include <string.h>
  63                 #include <stdbool.h>
  64
  65                 #include "HIDReportData.h"
  66                 #include "../Common/HID.h"
  67
  68                 #include "../../../../Common/Common.h"
  69
  70         /* Enable C linkage for C++ Compilers: */
  71                 #if defined(__cplusplus)
  72                         extern "C" {
  73                 #endif
  74
  75         /* Macros: */
  76                 #if !defined(HID_STATETABLE_STACK_DEPTH) || defined(__DOXYGEN__)
  77                         /** Constant indicating the maximum stack depth of the state table. A larger state table
  78                          *  allows for more PUSH/POP report items to be nested, but consumes more memory. By default
  79                          *  this is set to 2 levels (allowing non-nested PUSH items) but this can be overridden by
  80                          *  defining HID_STATETABLE_STACK_DEPTH to another value in the user project makefile, passing the
  81                          *  define to the compiler using the -D compiler switch.
  82                          */
  83                         #define HID_STATETABLE_STACK_DEPTH    2
  84                 #endif
  85
  86                 #if !defined(HID_USAGE_STACK_DEPTH) || defined(__DOXYGEN__)
  87                         /** Constant indicating the maximum stack depth of the usage table. A larger usage table
  88                          *  allows for more USAGE items to be indicated sequentially for REPORT COUNT entries of more than
  89                          *  one, but requires more stack space. By default this is set to 8 levels (allowing for a report
  90                          *  item with a count of 8) but this can be overridden by defining HID_USAGE_STACK_DEPTH to another
  91                          *  value in the user project makefile, passing the define to the compiler using the -D compiler
  92                          *  switch.
  93                          */
  94                         #define HID_USAGE_STACK_DEPTH         8
  95                 #endif
  96
  97                 #if !defined(HID_MAX_COLLECTIONS) || defined(__DOXYGEN__)
  98                         /** Constant indicating the maximum number of COLLECTION items (nested or unnested) that can be
  99                          *  processed in the report item descriptor. A large value allows for more COLLECTION items to be
 100                          *  processed, but consumes more memory. By default this is set to 10 collections, but this can be
 101                          *  overridden by defining HID_MAX_COLLECTIONS to another value in the user project makefile, passing
 102                          *  the define to the compiler using the -D compiler switch.
 103                          */
 104                         #define HID_MAX_COLLECTIONS           10
 105                 #endif
 106
 107                 #if !defined(HID_MAX_REPORTITEMS) || defined(__DOXYGEN__)
 108                         /** Constant indicating the maximum number of report items (IN, OUT or FEATURE) that can be processed
 109                          *  in the report item descriptor and stored in the user HID Report Info structure. A large value allows
 110                          *  for more report items to be stored, but consumes more memory. By default this is set to 20 items,
 111                          *  but this can be overridden by defining HID_MAX_REPORTITEMS to another value in the user project
 112                          *  makefile, and passing the define to the compiler using the -D compiler switch.
 113                          */
 114                         #define HID_MAX_REPORTITEMS           20
 115                 #endif
 116
 117                 #if !defined(HID_MAX_REPORT_IDS) || defined(__DOXYGEN__)
 118                         /** Constant indicating the maximum number of unique report IDs that can be processed in the report item
 119                          *  descriptor for the report size information array in the user HID Report Info structure. A large value
 120                          *  allows for more report ID report sizes to be stored, but consumes more memory. By default this is set
 121                          *  to 10 items, but this can be overridden by defining HID_MAX_REPORT_IDS to another value in the user project
 122                          *  makefile, and passing the define to the compiler using the -D compiler switch. Note that IN, OUT and FEATURE
 123                          *  items sharing the same report ID consume only one size item in the array.
 124                          */
 125                         #define HID_MAX_REPORT_IDS            10
 126                 #endif
 127
 128                 /** Returns the value a given HID report item (once its value has been fetched via \ref USB_GetHIDReportItemInfo())
 129                  *  left-aligned to the given data type. This allows for signed data to be interpreted correctly, by shifting the data
 130                  *  leftwards until the data's sign bit is in the correct position.
 131                  *
 132                  *  \param[in] ReportItem  HID Report Item whose retrieved value is to be aligned.
 133                  *  \param[in] Type        Data type to align the HID report item's value to.
 134                  *
 135                  *  \return Left-aligned data of the given report item's pre-retrieved value for the given datatype.
 136                  */
 137                 #define HID_ALIGN_DATA(ReportItem, Type) ((Type)(ReportItem->Value << ((8 * sizeof(Type)) - ReportItem->Attributes.BitSize)))
 138
 139         /* Public Interface - May be used in end-application: */
 140                 /* Enums: */
 141                         /** Enum for the possible error codes in the return value of the \ref USB_ProcessHIDReport() function. */
 142                         enum HID_Parse_ErrorCodes_t
 143                         {
 144                                 HID_PARSE_Successful                  = 0, /**< Successful parse of the HID report descriptor, no error. */
 145                                 HID_PARSE_HIDStackOverflow            = 1, /**< More than \ref HID_STATETABLE_STACK_DEPTH nested PUSHes in the report. */
 146                                 HID_PARSE_HIDStackUnderflow           = 2, /**< A POP was found when the state table stack was empty. */
 147                                 HID_PARSE_InsufficientReportItems     = 3, /**< More than \ref HID_MAX_REPORTITEMS report items in the report. */
 148                                 HID_PARSE_UnexpectedEndCollection     = 4, /**< An END COLLECTION item found without matching COLLECTION item. */
 149                                 HID_PARSE_InsufficientCollectionPaths = 5, /**< More than \ref HID_MAX_COLLECTIONS collections in the report. */
 150                                 HID_PARSE_UsageListOverflow           = 6, /**< More than \ref HID_USAGE_STACK_DEPTH usages listed in a row. */
 151                                 HID_PARSE_InsufficientReportIDItems   = 7, /**< More than \ref HID_MAX_REPORT_IDS report IDs in the device. */
 152                                 HID_PARSE_NoUnfilteredReportItems     = 8, /**< All report items from the device were filtered by the filtering callback routine. */
 153                         };
 154
 155                 /* Type Defines: */
 156                         /** \brief HID Parser Report Item Min/Max Structure.
 157                          *
 158                          *  Type define for an attribute with both minimum and maximum values (e.g. Logical Min/Max).
 159                          */
 160                         typedef struct
 161                         {
 162                                 uint32_t                     Minimum; /**< Minimum value for the attribute. */
 163                                 uint32_t                     Maximum; /**< Maximum value for the attribute. */
 164                         } HID_MinMax_t;
 165
 166                         /** \brief HID Parser Report Item Unit Structure.
 167                          *
 168                          *  Type define for the Unit attributes of a report item.
 169                          */
 170                         typedef struct
 171                         {
 172                                 uint32_t                     Type;     /**< Unit type (refer to HID specifications for details). */
 173                                 uint8_t                      Exponent; /**< Unit exponent (refer to HID specifications for details). */
 174                         } HID_Unit_t;
 175
 176                         /** \brief HID Parser Report Item Usage Structure.
 177                          *
 178                          *  Type define for the Usage attributes of a report item.
 179                          */
 180                         typedef struct
 181                         {
 182                                 uint16_t                     Page;   /**< Usage page of the report item. */
 183                                 uint16_t                     Usage;  /**< Usage of the report item. */
 184                         } HID_Usage_t;
 185
 186                         /** \brief HID Parser Report Item Collection Path Structure.
 187                          *
 188                          *  Type define for a COLLECTION object. Contains the collection attributes and a reference to the
 189                          *  parent collection if any.
 190                          */
 191                         typedef struct CollectionPath
 192                         {
 193                                 uint8_t                      Type;   /**< Collection type (e.g. "Generic Desktop"). */
 194                                 HID_Usage_t                  Usage;  /**< Collection usage. */
 195                                 struct CollectionPath*       Parent; /**< Reference to parent collection, or NULL if root collection. */
 196                         } HID_CollectionPath_t;
 197
 198                         /** \brief HID Parser Report Item Attributes Structure.
 199                          *
 200                          *  Type define for all the data attributes of a report item, except flags.
 201                          */
 202                         typedef struct
 203                         {
 204                                 uint8_t                      BitSize;  /**< Size in bits of the report item's data. */
 205
 206                                 HID_Usage_t                  Usage;    /**< Usage of the report item. */
 207                                 HID_Unit_t                   Unit;     /**< Unit type and exponent of the report item. */
 208                                 HID_MinMax_t                 Logical;  /**< Logical minimum and maximum of the report item. */
 209                                 HID_MinMax_t                 Physical; /**< Physical minimum and maximum of the report item. */
 210                         } HID_ReportItem_Attributes_t;
 211
 212                         /** \brief HID Parser Report Item Details Structure.
 213                          *
 214                          *  Type define for a report item (IN, OUT or FEATURE) layout attributes and other details.
 215                          */
 216                         typedef struct
 217                         {
 218                                 uint16_t                     BitOffset;      /**< Bit offset in the IN, OUT or FEATURE report of the item. */
 219                                 uint8_t                      ItemType;       /**< Report item type, a value in HID_ReportItemTypes_t. */
 220                                 uint16_t                     ItemFlags;      /**< Item data flags, such as constant/variable, etc. */
 221                                 uint8_t                      ReportID;       /**< Report ID this item belongs to, or 0x00 if device has only one report */
 222                                 HID_CollectionPath_t*        CollectionPath; /**< Collection path of the item. */
 223
 224                                 HID_ReportItem_Attributes_t  Attributes;     /**< Report item attributes. */
 225
 226                                 uint32_t                     Value;          /**< Current value of the report item - use \ref HID_ALIGN_DATA() when processing
 227                                                                               *   a retrieved value so that it is aligned to a specific type.
 228                                                                               */
 229                                 uint32_t                     PreviousValue;  /**< Previous value of the report item. */
 230                         } HID_ReportItem_t;
 231
 232                         /** \brief HID Parser Report Size Structure.
 233                          *
 234                          *  Type define for a report item size information structure, to retain the size of a device's reports by ID.
 235                          */
 236                         typedef struct
 237                         {
 238                                 uint8_t                      ReportID; /**< Report ID of the report within the HID interface. */
 239                                 uint16_t                     ReportSizeBits[3]; /**< Total number of bits in each report type for the given Report ID,
 240                                                                                  *   indexed by the \ref HID_ReportItemTypes_t enum.
 241                                                                                                                                  */
 242                         } HID_ReportSizeInfo_t;
 243
 244                         /** \brief HID Parser State Structure.
 245                          *
 246                          *  Type define for a complete processed HID report, including all report item data and collections.
 247                          */
 248                         typedef struct
 249                         {
 250                                 uint8_t                      TotalReportItems; /**< Total number of report items stored in the
 251                                                                                 *   ReportItems array.
 252                                                                                 */
 253                                 HID_ReportItem_t             ReportItems[HID_MAX_REPORTITEMS]; /**< Report items array, including
 254                                                                                             *   all IN, OUT and FEATURE items.
 255                                                                                                 */
 256                                 HID_CollectionPath_t         CollectionPaths[HID_MAX_COLLECTIONS]; /**< All collection items, referenced
 257                                                                                                     *   by the report items.
 258                                                                                                     */
 259                                 uint8_t                      TotalDeviceReports; /**< Number of reports within the HID interface */
 260                                 HID_ReportSizeInfo_t         ReportIDSizes[HID_MAX_REPORT_IDS]; /**< Report sizes for each report in the interface */
 261                                 uint16_t                     LargestReportSizeBits; /**< Largest report that the attached device will generate, in bits */
 262                                 bool                         UsingReportIDs; /**< Indicates if the device has at least one REPORT ID
 263                                                                               *   element in its HID report descriptor.
 264                                                                               */
 265                         } HID_ReportInfo_t;
 266
 267                 /* Function Prototypes: */
 268                         /** Function to process a given HID report returned from an attached device, and store it into a given
 269                          *  \ref HID_ReportInfo_t structure.
 270                          *
 271                          *  \param[in]  ReportData  Buffer containing the device's HID report table.
 272                          *  \param[in]  ReportSize  Size in bytes of the HID report table.
 273                          *  \param[out] ParserData  Pointer to a \ref HID_ReportInfo_t instance for the parser output.
 274                          *
 275                          *  \return A value in the \ref HID_Parse_ErrorCodes_t enum.
 276                          */
 277                         uint8_t USB_ProcessHIDReport(const uint8_t* ReportData,
 278                                                      uint16_t ReportSize,
 279                                                      HID_ReportInfo_t* const ParserData) ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(3);
 280
 281                         /** Extracts the given report item's value out of the given HID report and places it into the Value
 282                          *  member of the report item's \ref HID_ReportItem_t structure.
 283                          *
 284                          *  When called on a report with an item that exists in that report, this copies the report item's Value
 285                          *  to it's PreviousValue element for easy checking to see if an item's value has changed before processing
 286                          *  a report. If the given item does not exist in the report, the function does not modify the report item's
 287                          *  data.
 288                          *
 289                          *  \param[in]     ReportData  Buffer containing an IN or FEATURE report from an attached device.
 290                          *  \param[in,out] ReportItem  Pointer to the report item of interest in a \ref HID_ReportInfo_t ReportItem array.
 291                          *
 292                          *  \returns Boolean true if the item to retrieve was located in the given report, false otherwise.
 293                          */
 294                         bool USB_GetHIDReportItemInfo(const uint8_t* ReportData,
 295                                                       HID_ReportItem_t* const ReportItem) ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 296
 297                         /** Retrieves the given report item's value out of the Value member of the report item's
 298                          *  \ref HID_ReportItem_t structure and places it into the correct position in the HID report
 299                          *  buffer. The report buffer is assumed to have the appropriate bits cleared before calling
 300                          *  this function (i.e., the buffer should be explicitly cleared before report values are added).
 301                          *
 302                          *  When called, this copies the report item's Value element to it's PreviousValue element for easy
 303                          *  checking to see if an item's value has changed before sending a report.
 304                          *
 305                          *  If the device has multiple HID reports, the first byte in the report is set to the report ID of the given item.
 306                          *
 307                          *  \param[out] ReportData  Buffer holding the current OUT or FEATURE report data.
 308                          *  \param[in]  ReportItem  Pointer to the report item of interest in a \ref HID_ReportInfo_t ReportItem array.
 309                          */
 310                         void USB_SetHIDReportItemInfo(uint8_t* ReportData,
 311                                                       HID_ReportItem_t* const ReportItem) ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 312
 313                         /** Retrieves the size of a given HID report in bytes from it's Report ID.
 314                          *
 315                          *  \param[in] ParserData  Pointer to a \ref HID_ReportInfo_t instance containing the parser output.
 316                          *  \param[in] ReportID    Report ID of the report whose size is to be retrieved.
 317                          *  \param[in] ReportType  Type of the report whose size is to be determined, a valued from the
 318                          *                         \ref HID_ReportItemTypes_t enum.
 319                          *
 320                          *  \return Size of the report in bytes, or 0 if the report does not exist.
 321                          */
 322                         uint16_t USB_GetHIDReportSize(HID_ReportInfo_t* const ParserData,
 323                                                       const uint8_t ReportID,
 324                                                       const uint8_t ReportType) ATTR_CONST ATTR_NON_NULL_PTR_ARG(1);
 325
 326                         /** Callback routine for the HID Report Parser. This callback <b>must</b> be implemented by the user code when
 327                          *  the parser is used, to determine what report IN, OUT and FEATURE item's information is stored into the user
 328                          *  HID_ReportInfo_t structure. This can be used to filter only those items the application will be using, so that
 329                          *  no RAM is wasted storing the attributes for report items which will never be referenced by the application.
 330                          *
 331                          *  \param[in] CurrentItem  Pointer to the current report item for user checking.
 332                          *
 333                          *  \return Boolean true if the item should be stored into the HID_ReportInfo_t structure, false if it should be ignored.
 334                          */
 335                         bool CALLBACK_HIDParser_FilterHIDReportItem(HID_ReportItem_t* const CurrentItem);
 336
 337         /* Private Interface - For use in library only: */
 338         #if !defined(__DOXYGEN__)
 339                 /* Type Defines: */
 340                         typedef struct
 341                         {
 342                                  HID_ReportItem_Attributes_t Attributes;
 343                                  uint8_t                     ReportCount;
 344                                  uint8_t                     ReportID;
 345                         } HID_StateTable_t;
 346         #endif
 347
 348         /* Disable C linkage for C++ Compilers: */
 349                 #if defined(__cplusplus)
 350                         }
 351                 #endif
 352
 353 #endif
 354
 355 /** @} */
 356