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                         #define DESCRIPTOR_TYPE(DescriptorPtr)    DESCRIPTOR_CAST(DescriptorPtr, USB_Descriptor_Header_t).Type
 102
 103                         /** Returns the descriptor's size, expressed as the 8-bit value indicating the number of bytes. */
 104                         #define DESCRIPTOR_SIZE(DescriptorPtr)    DESCRIPTOR_CAST(DescriptorPtr, USB_Descriptor_Header_t).Size
 105
 106                 /* Type Defines: */
 107                         /** Type define for a Configuration Descriptor comparator function (function taking a pointer to an array
 108                          *  of type void, returning a uint8_t value).
 109                          *
 110                          *  \see \ref USB_GetNextDescriptorComp function for more details
 111                          */
 112                         typedef uint8_t (* const ConfigComparatorPtr_t)(void*);
 113
 114                 /* Function Prototypes: */
 115                         /** Searches for the next descriptor in the given configuration descriptor using a premade comparator
 116                          *  function. The routine updates the position and remaining configuration descriptor bytes values
 117                          *  automatically. If a comparator routine fails a search, the descriptor pointer is retreated back
 118                          *  so that the next descriptor search invocation will start from the descriptor which first caused the
 119                          *  original search to fail. This behaviour allows for one comparator to be used immediately after another
 120                          *  has failed, starting the second search from the descriptor which failed the first.
 121                          *
 122                          *  Comparator functions should be standard functions which accept a pointer to the header of the current
 123                          *  descriptor inside the configuration descriptor which is being compared, and should return a value from
 124                          *  the \ref DSearch_Return_ErrorCodes_t enum as a uint8_t value.
 125                          *
 126                          *  \note This function is available in USB Host mode only.
 127                          *
 128                          *  \param[in,out] BytesRem  Pointer to an int storing the remaining bytes in the configuration descriptor
 129                          *  \param[in,out] CurrConfigLoc  Pointer to the current position in the configuration descriptor
 130                          *  \param[in] ComparatorRoutine  Name of the comparator search function to use on the configuration descriptor
 131                          *
 132                          *  \return Value of one of the members of the \ref DSearch_Comp_Return_ErrorCodes_t enum
 133                          *
 134                          *  Usage Example:
 135                          *  \code
 136                          *  uint8_t EndpointSearcher(void* CurrentDescriptor); // Comparator Prototype
 137                          *
 138                          *  uint8_t EndpointSearcher(void* CurrentDescriptor)
 139                          *  {
 140                          *     if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Endpoint)
 141                          *         return DESCRIPTOR_SEARCH_Found;
 142                          *     else
 143                          *         return DESCRIPTOR_SEARCH_NotFound;
 144                          *  }
 145                          *
 146                          *  //...
 147                          *  // After retrieving configuration descriptor:
 148                          *  if (USB_Host_GetNextDescriptorComp(&BytesRemaining, &CurrentConfigLoc, EndpointSearcher) ==
 149                          *      Descriptor_Search_Comp_Found)
 150                          *  {
 151                          *      // Do something with the endpoint descriptor
 152                          *  }
 153                          *  \endcode
 154                          */
 155                         uint8_t USB_GetNextDescriptorComp(uint16_t* BytesRem, void** CurrConfigLoc, ConfigComparatorPtr_t ComparatorRoutine);
 156
 157                 /* Enums: */
 158                         /** Enum for the possible return codes of the \ref USB_Host_GetDeviceConfigDescriptor() function. */
 159                         enum USB_Host_GetConfigDescriptor_ErrorCodes_t
 160                         {
 161                                 HOST_GETCONFIG_Successful       = 0, /**< No error occurred while retrieving the configuration descriptor */
 162                                 HOST_GETCONFIG_DeviceDisconnect = 1, /**< The attached device was disconnected while retrieving the configuration
 163                                                                         * descriptor
 164                                                                         */
 165                                 HOST_GETCONFIG_PipeError        = 2, /**< An error occurred in the pipe while sending the request */
 166                                 HOST_GETCONFIG_SetupStalled     = 3, /**< The attached device stalled the request to retrieve the configuration
 167                                                                         * descriptor
 168                                                                         */
 169                                 HOST_GETCONFIG_SoftwareTimeOut  = 4, /**< The request or data transfer timed out */
 170                                 HOST_GETCONFIG_BuffOverflow     = 5, /**< The device's configuration descriptor is too large to fit into the allocated
 171                                                                         * buffer
 172                                                                         */
 173                                 HOST_GETCONFIG_InvalidData      = 6, /**< The device returned invalid configuration descriptor data */
 174                         };
 175
 176                         /** Enum for return values of a descriptor comparator function. */
 177                         enum DSearch_Return_ErrorCodes_t
 178                         {
 179                                 DESCRIPTOR_SEARCH_Found                = 0, /**< Current descriptor matches comparator criteria. */
 180                                 DESCRIPTOR_SEARCH_Fail                 = 1, /**< No further descriptor could possibly match criteria, fail the search. */
 181                                 DESCRIPTOR_SEARCH_NotFound             = 2, /**< Current descriptor does not match comparator criteria. */
 182                         };
 183
 184                         /** Enum for return values of \ref USB_GetNextDescriptorComp(). */
 185                         enum DSearch_Comp_Return_ErrorCodes_t
 186                         {
 187                                 DESCRIPTOR_SEARCH_COMP_Found           = 0, /**< Configuration descriptor now points to descriptor which matches
 188                                                                              *   search criteria of the given comparator function. */
 189                                 DESCRIPTOR_SEARCH_COMP_Fail            = 1, /**< Comparator function returned Descriptor_Search_Fail. */
 190                                 DESCRIPTOR_SEARCH_COMP_EndOfDescriptor = 2, /**< End of configuration descriptor reached before match found. */
 191                         };
 192
 193                 /* Function Prototypes: */
 194                         /** Retrieves the configuration descriptor data from an attached device via a standard request into a buffer,
 195                          *  including validity and size checking to prevent a buffer overflow.
 196                          *
 197                          *  \param[in] ConfigNumber  Device configuration descriptor number to fetch from the device (usually set to 1 for
 198                          *                           single configuration devices)
 199                          *  \param[in,out] ConfigSizePtr  Pointer to a uint16_t for storing the retrieved configuration descriptor size
 200                          *  \param[out] BufferPtr  Pointer to the buffer for storing the configuration descriptor data.
 201                          *  \param[out] BufferSize  Size of the allocated buffer where the configuration descriptor is to be stored
 202                          *
 203                          *  \return A value from the \ref USB_Host_GetConfigDescriptor_ErrorCodes_t enum
 204                          */
 205                         uint8_t USB_Host_GetDeviceConfigDescriptor(uint8_t ConfigNumber, uint16_t* const ConfigSizePtr, void* BufferPtr,
 206                                                                    uint16_t BufferSize) ATTR_NON_NULL_PTR_ARG(2) ATTR_NON_NULL_PTR_ARG(3);
 207
 208                         /** Skips to the next sub-descriptor inside the configuration descriptor of the specified type value.
 209                          *  The bytes remaining value is automatically decremented.
 210                          *
 211                          * \param[in,out] BytesRem  Pointer to the number of bytes remaining of the configuration descriptor
 212                          * \param[in,out] CurrConfigLoc  Pointer to the current descriptor inside the configuration descriptor
 213                          * \param[in] Type  Descriptor type value to search for
 214                          */
 215                         void USB_GetNextDescriptorOfType(uint16_t* const BytesRem,
 216                                                          void** const CurrConfigLoc,
 217                                                          const uint8_t Type)
 218                                                          ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 219
 220                         /** Skips to the next sub-descriptor inside the configuration descriptor of the specified type value,
 221                          *  which must come before a descriptor of the second given type value. If the BeforeType type
 222                          *  descriptor is reached first, the number of bytes remaining to process is set to zero and the
 223                          *  function exits. The bytes remaining value is automatically decremented.
 224                          *
 225                          * \param[in,out] BytesRem  Pointer to the number of bytes remaining of the configuration descriptor
 226                          * \param[in,out] CurrConfigLoc  Pointer to the current descriptor inside the configuration descriptor
 227                          * \param[in] Type  Descriptor type value to search for
 228                          * \param[in] BeforeType  Descriptor type value which must not be reached before the given Type descriptor
 229                          */
 230                         void USB_GetNextDescriptorOfTypeBefore(uint16_t* const BytesRem,
 231                                                                void** const CurrConfigLoc,
 232                                                                const uint8_t Type,
 233                                                                const uint8_t BeforeType)
 234                                                                ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 235
 236                         /** Skips to the next sub-descriptor inside the configuration descriptor of the specified type value,
 237                          *  which must come after a descriptor of the second given type value. The bytes remaining value is
 238                          *  automatically decremented.
 239                          *
 240                          * \param[in,out] BytesRem  Pointer to the number of bytes remaining of the configuration descriptor
 241                          * \param[in,out] CurrConfigLoc  Pointer to the current descriptor inside the configuration descriptor
 242                          * \param[in] Type  Descriptor type value to search for
 243                          * \param[in] AfterType  Descriptor type value which must be reached before the given Type descriptor
 244                          */
 245                         void USB_GetNextDescriptorOfTypeAfter(uint16_t* const BytesRem,
 246                                                               void** const CurrConfigLoc,
 247                                                               const uint8_t Type,
 248                                                               const uint8_t AfterType)
 249                                                               ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 250
 251                 /* Inline Functions: */
 252                         /** Skips over the current sub-descriptor inside the configuration descriptor, so that the pointer then
 253                             points to the next sub-descriptor. The bytes remaining value is automatically decremented.
 254                          *
 255                          * \param[in,out] BytesRem  Pointer to the number of bytes remaining of the configuration descriptor
 256                          * \param[in,out] CurrConfigLoc  Pointer to the current descriptor inside the configuration descriptor
 257                          */
 258                         static inline void USB_GetNextDescriptor(uint16_t* const BytesRem,
 259                                                                  void** const CurrConfigLoc)
 260                                                                  ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 261                         static inline void USB_GetNextDescriptor(uint16_t* const BytesRem,
 262                                                                  void** const CurrConfigLoc)
 263                         {
 264                                 uint16_t CurrDescriptorSize = DESCRIPTOR_CAST(*CurrConfigLoc, USB_Descriptor_Header_t).Size;
 265
 266                                 *CurrConfigLoc += CurrDescriptorSize;
 267                                 *BytesRem      -= CurrDescriptorSize;
 268                         }
 269
 270         /* Disable C linkage for C++ Compilers: */
 271                 #if defined(__cplusplus)
 272                         }
 273                 #endif
 274
 275 #endif
 276
 277 /** @} */