LUFA/Drivers/USB/HighLevel/ConfigDescriptor.h

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2009.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6       www.fourwalledcubicle.com
   7 */
   8
   9 /*
  10   Copyright 2009  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Permission to use, copy, modify, and distribute this software
  13   and its documentation for any purpose and without fee is hereby
  14   granted, provided that the above copyright notice appear in all
  15   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  *
  33  *  Configuration descriptor parser API. This section of the library gives a friendly API which can be used in
  34  *  host applications to easily parse an attached device's configuration descriptor so that endpoint, interface
  35  *  and other descriptor data can be extracted and used as needed.
  36  */
  37
  38 /** \ingroup Group_Descriptors
  39  *  @defgroup Group_ConfigDescriptorParser Configuration Descriptor Parser
  40  *
  41  *  Functions, macros, variables, enums and types related to the parsing of Configuration Descriptors.
  42  *
  43  *  @{
  44  */
  45
  46 #ifndef __CONFIGDESCRIPTOR_H__
  47 #define __CONFIGDESCRIPTOR_H__
  48
  49         /* Includes: */
  50                 #include <avr/io.h>
  51
  52                 #include "../../../Common/Common.h"
  53                 #include "../HighLevel/USBMode.h"
  54                 #include "../LowLevel/HostChapter9.h"
  55                 #include "../HighLevel/StdDescriptors.h"
  56
  57         /* Enable C linkage for C++ Compilers: */
  58                 #if defined(__cplusplus)
  59                         extern "C" {
  60                 #endif
  61
  62         /* Public Interface - May be used in end-application: */
  63                 /* Macros: */
  64                         /** Mask for determining the type of an endpoint from an endpoint descriptor. This should then be compared
  65                          *  with the EP_TYPE_* masks to determine the exact type of the endpoint.
  66                          */
  67                         #define EP_TYPE_MASK                       0x03
  68
  69                         /** Casts a pointer to a descriptor inside the configuration descriptor into a pointer to the given
  70                          *  descriptor type.
  71                          *
  72                          *  Usage Example:
  73                          *  \code
  74                          *  uint8_t* CurrDescriptor = &ConfigDescriptor[0]; // Pointing to the configuration header
  75                          *  USB_Descriptor_Configuration_Header_t* ConfigHeaderPtr = DESCRIPTOR_PCAST(CurrDescriptor,
  76                          *                                                           USB_Descriptor_Configuration_Header_t);
  77                          *
  78                          *  // Can now access elements of the configuration header struct using the -> indirection operator
  79                          *  \endcode
  80                          */
  81                         #define DESCRIPTOR_PCAST(DescriptorPtr, Type) ((Type*)DescriptorPtr)
  82
  83                         /** Casts a pointer to a descriptor inside the configuration descriptor into the given descriptor
  84                          *  type (as an actual struct instance rather than a pointer to a struct).
  85                          *
  86                          *  Usage Example:
  87                          *  \code
  88                          *  uint8_t* CurrDescriptor = &ConfigDescriptor[0]; // Pointing to the configuration header
  89                          *  USB_Descriptor_Configuration_Header_t ConfigHeader = DESCRIPTOR_CAST(CurrDescriptor,
  90                          *                                                       USB_Descriptor_Configuration_Header_t);
  91                          *
  92                          *  // Can now access elements of the configuration header struct using the . operator
  93                          *  \endcode
  94                          */
  95                         #define DESCRIPTOR_CAST(DescriptorPtr, Type)  (*DESCRIPTOR_PCAST(DescriptorPtr, Type))
  96
  97                         /** Returns the descriptor's type, expressed as the 8-bit type value in the header of the descriptor.
  98                          *  This value's meaning depends on the descriptor's placement in the descriptor, but standard type
  99                          *  values can be accessed in the \ref USB_DescriptorTypes_t enum.
 100                          */
 101                         #if defined(USE_NONSTANDARD_DESCRIPTOR_NAMES) || defined(__DOXYGEN__)
 102                                 #define DESCRIPTOR_TYPE(DescriptorPtr)    DESCRIPTOR_CAST(DescriptorPtr, USB_Descriptor_Header_t).Type
 103                         #else
 104                                 #define DESCRIPTOR_TYPE(DescriptorPtr)    DESCRIPTOR_CAST(DescriptorPtr, USB_Descriptor_Header_t).bDescriptorType
 105                         #endif
 106
 107                         /** Returns the descriptor's size, expressed as the 8-bit value indicating the number of bytes. */
 108                         #if defined(USE_NONSTANDARD_DESCRIPTOR_NAMES) || defined(__DOXYGEN__)
 109                                 #define DESCRIPTOR_SIZE(DescriptorPtr)    DESCRIPTOR_CAST(DescriptorPtr, USB_Descriptor_Header_t).Size
 110                         #else
 111                                 #define DESCRIPTOR_SIZE(DescriptorPtr)    DESCRIPTOR_CAST(DescriptorPtr, USB_Descriptor_Header_t).bLength
 112                         #endif
 113
 114                 /* Type Defines: */
 115                         /** Type define for a Configuration Descriptor comparator function (function taking a pointer to an array
 116                          *  of type void, returning a uint8_t value).
 117                          *
 118                          *  \see \ref USB_GetNextDescriptorComp function for more details
 119                          */
 120                         typedef uint8_t (* const ConfigComparatorPtr_t)(void* const);
 121
 122                 /* Function Prototypes: */
 123                         /** Searches for the next descriptor in the given configuration descriptor using a premade comparator
 124                          *  function. The routine updates the position and remaining configuration descriptor bytes values
 125                          *  automatically. If a comparator routine fails a search, the descriptor pointer is retreated back
 126                          *  so that the next descriptor search invocation will start from the descriptor which first caused the
 127                          *  original search to fail. This behaviour allows for one comparator to be used immediately after another
 128                          *  has failed, starting the second search from the descriptor which failed the first.
 129                          *
 130                          *  Comparator functions should be standard functions which accept a pointer to the header of the current
 131                          *  descriptor inside the configuration descriptor which is being compared, and should return a value from
 132                          *  the \ref DSearch_Return_ErrorCodes_t enum as a uint8_t value.
 133                          *
 134                          *  \note This function is available in USB Host mode only.
 135                          *
 136                          *  \param[in,out] BytesRem  Pointer to an int storing the remaining bytes in the configuration descriptor
 137                          *  \param[in,out] CurrConfigLoc  Pointer to the current position in the configuration descriptor
 138                          *  \param[in] ComparatorRoutine  Name of the comparator search function to use on the configuration descriptor
 139                          *
 140                          *  \return Value of one of the members of the \ref DSearch_Comp_Return_ErrorCodes_t enum
 141                          *
 142                          *  Usage Example:
 143                          *  \code
 144                          *  uint8_t EndpointSearcher(void* CurrentDescriptor); // Comparator Prototype
 145                          *
 146                          *  uint8_t EndpointSearcher(void* CurrentDescriptor)
 147                          *  {
 148                          *     if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Endpoint)
 149                          *         return DESCRIPTOR_SEARCH_Found;
 150                          *     else
 151                          *         return DESCRIPTOR_SEARCH_NotFound;
 152                          *  }
 153                          *
 154                          *  //...
 155                          *  // After retrieving configuration descriptor:
 156                          *  if (USB_Host_GetNextDescriptorComp(&BytesRemaining, &ConfigDescriptorData, EndpointSearcher) ==
 157                          *      Descriptor_Search_Comp_Found)
 158                          *  {
 159                          *      // Do something with the endpoint descriptor
 160                          *  }
 161                          *  \endcode
 162                          */
 163                         uint8_t USB_GetNextDescriptorComp(uint16_t* BytesRem, uint8_t** CurrConfigLoc, ConfigComparatorPtr_t ComparatorRoutine);
 164
 165                 /* Enums: */
 166                         /** Enum for return values of a descriptor comparator function. */
 167                         enum DSearch_Return_ErrorCodes_t
 168                         {
 169                                 DESCRIPTOR_SEARCH_Found                = 0, /**< Current descriptor matches comparator criteria. */
 170                                 DESCRIPTOR_SEARCH_Fail                 = 1, /**< No further descriptor could possibly match criteria, fail the search. */
 171                                 DESCRIPTOR_SEARCH_NotFound             = 2, /**< Current descriptor does not match comparator criteria. */
 172                         };
 173
 174                         /** Enum for return values of \ref USB_GetNextDescriptorComp(). */
 175                         enum DSearch_Comp_Return_ErrorCodes_t
 176                         {
 177                                 DESCRIPTOR_SEARCH_COMP_Found           = 0, /**< Configuration descriptor now points to descriptor which matches
 178                                                                              *   search criteria of the given comparator function. */
 179                                 DESCRIPTOR_SEARCH_COMP_Fail            = 1, /**< Comparator function returned Descriptor_Search_Fail. */
 180                                 DESCRIPTOR_SEARCH_COMP_EndOfDescriptor = 2, /**< End of configuration descriptor reached before match found. */
 181                         };
 182
 183                 /* Function Prototypes: */
 184                         /** Retrieves the configuration descriptor data or size from an attached device via a standard request.
 185                          *
 186                          *  \param[in] ConfigNumber  Device configuration descriptor number to fetch from the device (usually set to 1 for
 187                          *                           single configuration devices)
 188                          *
 189                          *  \param[in,out] ConfigSizePtr  Pointer to a uint16_t for either storing or retrieving the configuration
 190                          *                                descriptor size
 191                          *
 192                          *  \param[out] BufferPtr  Pointer to the buffer for storing the configuration descriptor data. If this is
 193                          *                         NULL, the size of the configuration descriptor will be retrieved instead and
 194                          *                         placed in the variable pointed to by ConfigSizePtr. If this is non-NULL, the number
 195                          *                         of bytes indicated by ConfigSizePtr of the configuration descriptor will be loaded
 196                          *                         into the buffer
 197                          */
 198                         uint8_t USB_GetDeviceConfigDescriptor(uint8_t ConfigNumber, uint16_t* const ConfigSizePtr, void* BufferPtr)
 199                                                               ATTR_NON_NULL_PTR_ARG(2);
 200
 201                         /** Skips to the next sub-descriptor inside the configuration descriptor of the specified type value.
 202                          *  The bytes remaining value is automatically decremented.
 203                          *
 204                          * \param[in,out] BytesRem  Pointer to the number of bytes remaining of the configuration descriptor
 205                          * \param[in,out] CurrConfigLoc  Pointer to the current descriptor inside the configuration descriptor
 206                          * \param[in] Type  Descriptor type value to search for
 207                          */
 208                         void USB_GetNextDescriptorOfType(uint16_t* const BytesRem,
 209                                                          uint8_t** const CurrConfigLoc,
 210                                                          const uint8_t Type)
 211                                                          ATTR_NON_NULL_PTR_ARG(1, 2);
 212
 213                         /** Skips to the next sub-descriptor inside the configuration descriptor of the specified type value,
 214                          *  which must come before a descriptor of the second given type value. If the BeforeType type
 215                          *  descriptor is reached first, the number of bytes remaining to process is set to zero and the
 216                          *  function exits. The bytes remaining value is automatically decremented.
 217                          *
 218                          * \param[in,out] BytesRem  Pointer to the number of bytes remaining of the configuration descriptor
 219                          * \param[in,out] CurrConfigLoc  Pointer to the current descriptor inside the configuration descriptor
 220                          * \param[in] Type  Descriptor type value to search for
 221                          * \param[in] BeforeType  Descriptor type value which must not be reached before the given Type descriptor
 222                          */
 223                         void USB_GetNextDescriptorOfTypeBefore(uint16_t* const BytesRem,
 224                                                                uint8_t** const CurrConfigLoc,
 225                                                                const uint8_t Type,
 226                                                                const uint8_t BeforeType)
 227                                                                ATTR_NON_NULL_PTR_ARG(1, 2);
 228
 229                         /** Skips to the next sub-descriptor inside the configuration descriptor of the specified type value,
 230                          *  which must come after a descriptor of the second given type value. The bytes remaining value is
 231                          *  automatically decremented.
 232                          *
 233                          * \param[in,out] BytesRem  Pointer to the number of bytes remaining of the configuration descriptor
 234                          * \param[in,out] CurrConfigLoc  Pointer to the current descriptor inside the configuration descriptor
 235                          * \param[in] Type  Descriptor type value to search for
 236                          * \param[in] AfterType  Descriptor type value which must be reached before the given Type descriptor
 237                          */
 238                         void USB_GetNextDescriptorOfTypeAfter(uint16_t* const BytesRem,
 239                                                               uint8_t** const CurrConfigLoc,
 240                                                               const uint8_t Type,
 241                                                               const uint8_t AfterType)
 242                                                               ATTR_NON_NULL_PTR_ARG(1, 2);
 243
 244                 /* Inline Functions: */
 245                         /** Skips over the current sub-descriptor inside the configuration descriptor, so that the pointer then
 246                             points to the next sub-descriptor. The bytes remaining value is automatically decremented.
 247                          *
 248                          * \param[in,out] BytesRem  Pointer to the number of bytes remaining of the configuration descriptor
 249                          * \param[in,out] CurrConfigLoc  Pointer to the current descriptor inside the configuration descriptor
 250                          */
 251                         static inline void USB_GetNextDescriptor(uint16_t* const BytesRem,
 252                                                                  uint8_t** const CurrConfigLoc)
 253                                                                  ATTR_NON_NULL_PTR_ARG(1, 2);
 254                         static inline void USB_GetNextDescriptor(uint16_t* const BytesRem,
 255                                                                  uint8_t** const CurrConfigLoc)
 256                         {
 257                                 #if defined(USE_NONSTANDARD_DESCRIPTOR_NAMES)
 258                                 uint16_t CurrDescriptorSize = DESCRIPTOR_CAST(*CurrConfigLoc, USB_Descriptor_Header_t).Size;
 259                                 #else
 260                                 uint16_t CurrDescriptorSize = DESCRIPTOR_CAST(*CurrConfigLoc, USB_Descriptor_Header_t).bLength;
 261                                 #endif
 262
 263                                 *CurrConfigLoc += CurrDescriptorSize;
 264                                 *BytesRem      -= CurrDescriptorSize;
 265                         }
 266
 267         /* Disable C linkage for C++ Compilers: */
 268                 #if defined(__cplusplus)
 269                         }
 270                 #endif
 271
 272 #endif
 273
 274 /** @} */