LUFA/Drivers/USB/Core/ConfigDescriptor.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 Configuration Descriptor definitions.
  33  *  \copydetails Group_ConfigDescriptorParser
  34  *
  35  *  \note This file should not be included directly. It is automatically included as needed by the USB driver
  36  *        dispatch header located in LUFA/Drivers/USB/USB.h.
  37  */
  38
  39 /** \ingroup Group_Descriptors
  40  *  \defgroup Group_ConfigDescriptorParser Configuration Descriptor Parser
  41  *  \brief USB Configuration Descriptor definitions.
  42  *
  43  *  This section of the library gives a friendly API which can be used in host applications to easily
  44  *  parse an attached device's configuration descriptor so that endpoint, interface and other descriptor
  45  *  data can be extracted and used as needed.
  46  *
  47  *  @{
  48  */
  49
  50 #ifndef __CONFIGDESCRIPTOR_H__
  51 #define __CONFIGDESCRIPTOR_H__
  52
  53         /* Includes: */
  54                 #include "../../../Common/Common.h"
  55                 #include "USBMode.h"
  56                 #include "HostStandardReq.h"
  57                 #include "StdDescriptors.h"
  58
  59         /* Enable C linkage for C++ Compilers: */
  60                 #if defined(__cplusplus)
  61                         extern "C" {
  62                 #endif
  63
  64         /* Preprocessor Checks: */
  65                 #if !defined(__INCLUDE_FROM_USB_DRIVER)
  66                         #error Do not include this file directly. Include LUFA/Drivers/USB/USB.h instead.
  67                 #endif
  68
  69         /* Public Interface - May be used in end-application: */
  70                 /* Macros: */
  71                         /** Mask for determining the type of an endpoint from an endpoint descriptor. This should then be compared
  72                          *  with the \c EP_TYPE_* masks to determine the exact type of the endpoint.
  73                          */
  74                         #define EP_TYPE_MASK                       0x03
  75
  76                         /** Casts a pointer to a descriptor inside the configuration descriptor into a pointer to the given
  77                          *  descriptor type.
  78                          *
  79                          *  Usage Example:
  80                          *  \code
  81                          *  uint8_t* CurrDescriptor = &ConfigDescriptor[0]; // Pointing to the configuration header
  82                          *  USB_Descriptor_Configuration_Header_t* ConfigHeaderPtr = DESCRIPTOR_PCAST(CurrDescriptor,
  83                          *                                                           USB_Descriptor_Configuration_Header_t);
  84                          *
  85                          *  // Can now access elements of the configuration header struct using the -> indirection operator
  86                          *  \endcode
  87                          */
  88                         #define DESCRIPTOR_PCAST(DescriptorPtr, Type) ((Type*)(DescriptorPtr))
  89
  90                         /** Casts a pointer to a descriptor inside the configuration descriptor into the given descriptor
  91                          *  type (as an actual struct instance rather than a pointer to a struct).
  92                          *
  93                          *  Usage Example:
  94                          *  \code
  95                          *  uint8_t* CurrDescriptor = &ConfigDescriptor[0]; // Pointing to the configuration header
  96                          *  USB_Descriptor_Configuration_Header_t ConfigHeader = DESCRIPTOR_CAST(CurrDescriptor,
  97                          *                                                       USB_Descriptor_Configuration_Header_t);
  98                          *
  99                          *  // Can now access elements of the configuration header struct using the . operator
 100                          *  \endcode
 101                          */
 102                         #define DESCRIPTOR_CAST(DescriptorPtr, Type)  (*DESCRIPTOR_PCAST(DescriptorPtr, Type))
 103
 104                         /** Returns the descriptor's type, expressed as the 8-bit type value in the header of the descriptor.
 105                          *  This value's meaning depends on the descriptor's placement in the descriptor, but standard type
 106                          *  values can be accessed in the \ref USB_DescriptorTypes_t enum.
 107                          */
 108                         #define DESCRIPTOR_TYPE(DescriptorPtr)    DESCRIPTOR_PCAST(DescriptorPtr, USB_Descriptor_Header_t)->Type
 109
 110                         /** Returns the descriptor's size, expressed as the 8-bit value indicating the number of bytes. */
 111                         #define DESCRIPTOR_SIZE(DescriptorPtr)    DESCRIPTOR_PCAST(DescriptorPtr, USB_Descriptor_Header_t)->Size
 112
 113                 /* Type Defines: */
 114                         /** Type define for a Configuration Descriptor comparator function (function taking a pointer to an array
 115                          *  of type void, returning a uint8_t value).
 116                          *
 117                          *  \see \ref USB_GetNextDescriptorComp function for more details.
 118                          */
 119                         typedef uint8_t (* ConfigComparatorPtr_t)(void*);
 120
 121                 /* Enums: */
 122                         /** Enum for the possible return codes of the \ref USB_Host_GetDeviceConfigDescriptor() function. */
 123                         enum USB_Host_GetConfigDescriptor_ErrorCodes_t
 124                         {
 125                                 HOST_GETCONFIG_Successful       = 0, /**< No error occurred while retrieving the configuration descriptor. */
 126                                 HOST_GETCONFIG_DeviceDisconnect = 1, /**< The attached device was disconnected while retrieving the configuration
 127                                                                         * descriptor.
 128                                                                         */
 129                                 HOST_GETCONFIG_PipeError        = 2, /**< An error occurred in the pipe while sending the request. */
 130                                 HOST_GETCONFIG_SetupStalled     = 3, /**< The attached device stalled the request to retrieve the configuration
 131                                                                         * descriptor.
 132                                                                         */
 133                                 HOST_GETCONFIG_SoftwareTimeOut  = 4, /**< The request or data transfer timed out. */
 134                                 HOST_GETCONFIG_BuffOverflow     = 5, /**< The device's configuration descriptor is too large to fit into the allocated
 135                                                                         * buffer.
 136                                                                         */
 137                                 HOST_GETCONFIG_InvalidData      = 6, /**< The device returned invalid configuration descriptor data. */
 138                         };
 139
 140                         /** Enum for return values of a descriptor comparator function. */
 141                         enum DSearch_Return_ErrorCodes_t
 142                         {
 143                                 DESCRIPTOR_SEARCH_Found                = 0, /**< Current descriptor matches comparator criteria. */
 144                                 DESCRIPTOR_SEARCH_Fail                 = 1, /**< No further descriptor could possibly match criteria, fail the search. */
 145                                 DESCRIPTOR_SEARCH_NotFound             = 2, /**< Current descriptor does not match comparator criteria. */
 146                         };
 147
 148                         /** Enum for return values of \ref USB_GetNextDescriptorComp(). */
 149                         enum DSearch_Comp_Return_ErrorCodes_t
 150                         {
 151                                 DESCRIPTOR_SEARCH_COMP_Found           = 0, /**< Configuration descriptor now points to descriptor which matches
 152                                                                              *   search criteria of the given comparator function. */
 153                                 DESCRIPTOR_SEARCH_COMP_Fail            = 1, /**< Comparator function returned \ref DESCRIPTOR_SEARCH_Fail. */
 154                                 DESCRIPTOR_SEARCH_COMP_EndOfDescriptor = 2, /**< End of configuration descriptor reached before match found. */
 155                         };
 156
 157                 /* Function Prototypes: */
 158                         /** Retrieves the configuration descriptor data from an attached device via a standard request into a buffer,
 159                          *  including validity and size checking to prevent a buffer overflow.
 160                          *
 161                          *  \param[in]     ConfigNumber   Device configuration descriptor number to fetch from the device (usually set to 1 for
 162                          *                                single configuration devices).
 163                          *  \param[in,out] ConfigSizePtr  Pointer to a location for storing the retrieved configuration descriptor size.
 164                          *  \param[out]    BufferPtr      Pointer to the buffer for storing the configuration descriptor data.
 165                          *  \param[out]    BufferSize     Size of the allocated buffer where the configuration descriptor is to be stored.
 166                          *
 167                          *  \return A value from the \ref USB_Host_GetConfigDescriptor_ErrorCodes_t enum.
 168                          */
 169                         uint8_t USB_Host_GetDeviceConfigDescriptor(const uint8_t ConfigNumber,
 170                                                                    uint16_t* const ConfigSizePtr,
 171                                                                    void* const BufferPtr,
 172                                                                    const uint16_t BufferSize) ATTR_NON_NULL_PTR_ARG(2) ATTR_NON_NULL_PTR_ARG(3);
 173
 174                         /** Skips to the next sub-descriptor inside the configuration descriptor of the specified type value.
 175                          *  The bytes remaining value is automatically decremented.
 176                          *
 177                          * \param[in,out] BytesRem       Pointer to the number of bytes remaining of the configuration descriptor.
 178                          * \param[in,out] CurrConfigLoc  Pointer to the current descriptor inside the configuration descriptor.
 179                          * \param[in]     Type           Descriptor type value to search for.
 180                          */
 181                         void USB_GetNextDescriptorOfType(uint16_t* const BytesRem,
 182                                                          void** const CurrConfigLoc,
 183                                                          const uint8_t Type)
 184                                                          ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 185
 186                         /** Skips to the next sub-descriptor inside the configuration descriptor of the specified type value,
 187                          *  which must come before a descriptor of the second given type value. If the BeforeType type
 188                          *  descriptor is reached first, the number of bytes remaining to process is set to zero and the
 189                          *  function exits. The bytes remaining value is automatically decremented.
 190                          *
 191                          * \param[in,out] BytesRem       Pointer to the number of bytes remaining of the configuration descriptor.
 192                          * \param[in,out] CurrConfigLoc  Pointer to the current descriptor inside the configuration descriptor.
 193                          * \param[in]     Type           Descriptor type value to search for.
 194                          * \param[in]     BeforeType     Descriptor type value which must not be reached before the given Type descriptor.
 195                          */
 196                         void USB_GetNextDescriptorOfTypeBefore(uint16_t* const BytesRem,
 197                                                                void** const CurrConfigLoc,
 198                                                                const uint8_t Type,
 199                                                                const uint8_t BeforeType)
 200                                                                ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 201
 202                         /** Skips to the next sub-descriptor inside the configuration descriptor of the specified type value,
 203                          *  which must come after a descriptor of the second given type value. The bytes remaining value is
 204                          *  automatically decremented.
 205                          *
 206                          * \param[in,out] BytesRem       Pointer to the number of bytes remaining of the configuration descriptor.
 207                          * \param[in,out] CurrConfigLoc  Pointer to the current descriptor inside the configuration descriptor.
 208                          * \param[in]     Type           Descriptor type value to search for.
 209                          * \param[in]     AfterType      Descriptor type value which must be reached before the given Type descriptor.
 210                          */
 211                         void USB_GetNextDescriptorOfTypeAfter(uint16_t* const BytesRem,
 212                                                               void** const CurrConfigLoc,
 213                                                               const uint8_t Type,
 214                                                               const uint8_t AfterType)
 215                                                               ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 216
 217                         /** Searches for the next descriptor in the given configuration descriptor using a pre-made comparator
 218                          *  function. The routine updates the position and remaining configuration descriptor bytes values
 219                          *  automatically. If a comparator routine fails a search, the descriptor pointer is retreated back
 220                          *  so that the next descriptor search invocation will start from the descriptor which first caused the
 221                          *  original search to fail. This behaviour allows for one comparator to be used immediately after another
 222                          *  has failed, starting the second search from the descriptor which failed the first.
 223                          *
 224                          *  Comparator functions should be standard functions which accept a pointer to the header of the current
 225                          *  descriptor inside the configuration descriptor which is being compared, and should return a value from
 226                          *  the \ref DSearch_Return_ErrorCodes_t enum as a uint8_t value.
 227                          *
 228                          *  \note This function is available in USB Host mode only.
 229                          *
 230                          *  \param[in,out] BytesRem           Pointer to an int storing the remaining bytes in the configuration descriptor.
 231                          *  \param[in,out] CurrConfigLoc      Pointer to the current position in the configuration descriptor.
 232                          *  \param[in]     ComparatorRoutine  Name of the comparator search function to use on the configuration descriptor.
 233                          *
 234                          *  \return Value of one of the members of the \ref DSearch_Comp_Return_ErrorCodes_t enum.
 235                          *
 236                          *  Usage Example:
 237                          *  \code
 238                          *  uint8_t EndpointSearcher(void* CurrentDescriptor); // Comparator Prototype
 239                          *
 240                          *  uint8_t EndpointSearcher(void* CurrentDescriptor)
 241                          *  {
 242                          *     if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Endpoint)
 243                          *         return DESCRIPTOR_SEARCH_Found;
 244                          *     else
 245                          *         return DESCRIPTOR_SEARCH_NotFound;
 246                          *  }
 247                          *
 248                          *  //...
 249                          *  // After retrieving configuration descriptor:
 250                          *  if (USB_Host_GetNextDescriptorComp(&BytesRemaining, &CurrentConfigLoc, EndpointSearcher) ==
 251                          *      Descriptor_Search_Comp_Found)
 252                          *  {
 253                          *      // Do something with the endpoint descriptor
 254                          *  }
 255                          *  \endcode
 256                          */
 257                         uint8_t USB_GetNextDescriptorComp(uint16_t* const BytesRem,
 258                                                           void** const CurrConfigLoc,
 259                                                           ConfigComparatorPtr_t const ComparatorRoutine);
 260
 261                 /* Inline Functions: */
 262                         /** Skips over the current sub-descriptor inside the configuration descriptor, so that the pointer then
 263                             points to the next sub-descriptor. The bytes remaining value is automatically decremented.
 264                          *
 265                          * \param[in,out] BytesRem       Pointer to the number of bytes remaining of the configuration descriptor.
 266                          * \param[in,out] CurrConfigLoc  Pointer to the current descriptor inside the configuration descriptor.
 267                          */
 268                         static inline void USB_GetNextDescriptor(uint16_t* const BytesRem,
 269                                                                  void** CurrConfigLoc) ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 270                         static inline void USB_GetNextDescriptor(uint16_t* const BytesRem,
 271                                                                  void** CurrConfigLoc)
 272                         {
 273                                 uint16_t CurrDescriptorSize = DESCRIPTOR_CAST(*CurrConfigLoc, USB_Descriptor_Header_t).Size;
 274
 275                                 if (*BytesRem < CurrDescriptorSize)
 276                                   CurrDescriptorSize = *BytesRem;
 277
 278                                 *CurrConfigLoc  = (void*)((uintptr_t)*CurrConfigLoc + CurrDescriptorSize);
 279                                 *BytesRem      -= CurrDescriptorSize;
 280                         }
 281
 282         /* Disable C linkage for C++ Compilers: */
 283                 #if defined(__cplusplus)
 284                         }
 285                 #endif
 286
 287 #endif
 288
 289 /** @} */
 290