LUFA/Drivers/USB/Core/ConfigDescriptors.h

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2015.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6            www.lufa-lib.org
   7 */
   8
   9 /*
  10   Copyright 2015  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 disclaims 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_StdDescriptors
  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 __CONFIGDESCRIPTORS_H__
  51 #define __CONFIGDESCRIPTORS_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                         /** Casts a pointer to a descriptor inside the configuration descriptor into a pointer to the given
  72                          *  descriptor type.
  73                          *
  74                          *  Usage Example:
  75                          *  \code
  76                          *  uint8_t* CurrDescriptor = &ConfigDescriptor[0]; // Pointing to the configuration header
  77                          *  USB_Descriptor_Configuration_Header_t* ConfigHeaderPtr = DESCRIPTOR_PCAST(CurrDescriptor,
  78                          *                                                           USB_Descriptor_Configuration_Header_t);
  79                          *
  80                          *  // Can now access elements of the configuration header struct using the -> indirection operator
  81                          *  \endcode
  82                          */
  83                         #define DESCRIPTOR_PCAST(DescriptorPtr, Type) ((Type*)(DescriptorPtr))
  84
  85                         /** Casts a pointer to a descriptor inside the configuration descriptor into the given descriptor
  86                          *  type (as an actual struct instance rather than a pointer to a struct).
  87                          *
  88                          *  Usage Example:
  89                          *  \code
  90                          *  uint8_t* CurrDescriptor = &ConfigDescriptor[0]; // Pointing to the configuration header
  91                          *  USB_Descriptor_Configuration_Header_t ConfigHeader = DESCRIPTOR_CAST(CurrDescriptor,
  92                          *                                                       USB_Descriptor_Configuration_Header_t);
  93                          *
  94                          *  // Can now access elements of the configuration header struct using the . operator
  95                          *  \endcode
  96                          */
  97                         #define DESCRIPTOR_CAST(DescriptorPtr, Type)  (*DESCRIPTOR_PCAST(DescriptorPtr, Type))
  98
  99                         /** Returns the descriptor's type, expressed as the 8-bit type value in the header of the descriptor.
 100                          *  This value's meaning depends on the descriptor's placement in the descriptor, but standard type
 101                          *  values can be accessed in the \ref USB_DescriptorTypes_t enum.
 102                          */
 103                         #define DESCRIPTOR_TYPE(DescriptorPtr)    DESCRIPTOR_PCAST(DescriptorPtr, USB_Descriptor_Header_t)->Type
 104
 105                         /** Returns the descriptor's size, expressed as the 8-bit value indicating the number of bytes. */
 106                         #define DESCRIPTOR_SIZE(DescriptorPtr)    DESCRIPTOR_PCAST(DescriptorPtr, USB_Descriptor_Header_t)->Size
 107
 108                 /* Type Defines: */
 109                         /** Type define for a Configuration Descriptor comparator function (function taking a pointer to an array
 110                          *  of type void, returning a uint8_t value).
 111                          *
 112                          *  \see \ref USB_GetNextDescriptorComp function for more details.
 113                          */
 114                         typedef uint8_t (* ConfigComparatorPtr_t)(void*);
 115
 116                 /* Enums: */
 117                         /** Enum for the possible return codes of the \ref USB_Host_GetDeviceConfigDescriptor() function. */
 118                         enum USB_Host_GetConfigDescriptor_ErrorCodes_t
 119                         {
 120                                 HOST_GETCONFIG_Successful       = 0, /**< No error occurred while retrieving the configuration descriptor. */
 121                                 HOST_GETCONFIG_DeviceDisconnect = 1, /**< The attached device was disconnected while retrieving the configuration
 122                                                                       *   descriptor.
 123                                                                       */
 124                                 HOST_GETCONFIG_PipeError        = 2, /**< An error occurred in the pipe while sending the request. */
 125                                 HOST_GETCONFIG_SetupStalled     = 3, /**< The attached device stalled the request to retrieve the configuration
 126                                                                       *   descriptor.
 127                                                                       */
 128                                 HOST_GETCONFIG_SoftwareTimeOut  = 4, /**< The request or data transfer timed out. */
 129                                 HOST_GETCONFIG_BuffOverflow     = 5, /**< The device's configuration descriptor is too large to fit into the allocated
 130                                                                       *   buffer.
 131                                                                       */
 132                                 HOST_GETCONFIG_InvalidData      = 6, /**< The device returned invalid configuration descriptor data. */
 133                         };
 134
 135                         /** Enum for return values of a descriptor comparator function. */
 136                         enum DSearch_Return_ErrorCodes_t
 137                         {
 138                                 DESCRIPTOR_SEARCH_Found                = 0, /**< Current descriptor matches comparator criteria. */
 139                                 DESCRIPTOR_SEARCH_Fail                 = 1, /**< No further descriptor could possibly match criteria, fail the search. */
 140                                 DESCRIPTOR_SEARCH_NotFound             = 2, /**< Current descriptor does not match comparator criteria. */
 141                         };
 142
 143                         /** Enum for return values of \ref USB_GetNextDescriptorComp(). */
 144                         enum DSearch_Comp_Return_ErrorCodes_t
 145                         {
 146                                 DESCRIPTOR_SEARCH_COMP_Found           = 0, /**< Configuration descriptor now points to descriptor which matches
 147                                                                              *   search criteria of the given comparator function. */
 148                                 DESCRIPTOR_SEARCH_COMP_Fail            = 1, /**< Comparator function returned \ref DESCRIPTOR_SEARCH_Fail. */
 149                                 DESCRIPTOR_SEARCH_COMP_EndOfDescriptor = 2, /**< End of configuration descriptor reached before match found. */
 150                         };
 151
 152                 /* Function Prototypes: */
 153                         /** Retrieves the configuration descriptor data from an attached device via a standard request into a buffer,
 154                          *  including validity and size checking to prevent a buffer overflow.
 155                          *
 156                          *  \param[in]     ConfigNumber   Device configuration descriptor number to fetch from the device (usually set to 1 for
 157                          *                                single configuration devices).
 158                          *  \param[in,out] ConfigSizePtr  Pointer to a location for storing the retrieved configuration descriptor size.
 159                          *  \param[out]    BufferPtr      Pointer to the buffer for storing the configuration descriptor data.
 160                          *  \param[out]    BufferSize     Size of the allocated buffer where the configuration descriptor is to be stored.
 161                          *
 162                          *  \return A value from the \ref USB_Host_GetConfigDescriptor_ErrorCodes_t enum.
 163                          */
 164                         uint8_t USB_Host_GetDeviceConfigDescriptor(const uint8_t ConfigNumber,
 165                                                                    uint16_t* const ConfigSizePtr,
 166                                                                    void* const BufferPtr,
 167                                                                    const uint16_t BufferSize) ATTR_NON_NULL_PTR_ARG(2) ATTR_NON_NULL_PTR_ARG(3);
 168
 169                         /** Skips to the next sub-descriptor inside the configuration descriptor of the specified type value.
 170                          *  The bytes remaining value is automatically decremented.
 171                          *
 172                          * \param[in,out] BytesRem       Pointer to the number of bytes remaining of the configuration descriptor.
 173                          * \param[in,out] CurrConfigLoc  Pointer to the current descriptor inside the configuration descriptor.
 174                          * \param[in]     Type           Descriptor type value to search for.
 175                          */
 176                         void USB_GetNextDescriptorOfType(uint16_t* const BytesRem,
 177                                                          void** const CurrConfigLoc,
 178                                                          const uint8_t Type)
 179                                                          ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 180
 181                         /** Skips to the next sub-descriptor inside the configuration descriptor of the specified type value,
 182                          *  which must come before a descriptor of the second given type value. If the BeforeType type
 183                          *  descriptor is reached first, the number of bytes remaining to process is set to zero and the
 184                          *  function exits. The bytes remaining value is automatically decremented.
 185                          *
 186                          * \param[in,out] BytesRem       Pointer to the number of bytes remaining of the configuration descriptor.
 187                          * \param[in,out] CurrConfigLoc  Pointer to the current descriptor inside the configuration descriptor.
 188                          * \param[in]     Type           Descriptor type value to search for.
 189                          * \param[in]     BeforeType     Descriptor type value which must not be reached before the given Type descriptor.
 190                          */
 191                         void USB_GetNextDescriptorOfTypeBefore(uint16_t* const BytesRem,
 192                                                                void** const CurrConfigLoc,
 193                                                                const uint8_t Type,
 194                                                                const uint8_t BeforeType)
 195                                                                ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 196
 197                         /** Skips to the next sub-descriptor inside the configuration descriptor of the specified type value,
 198                          *  which must come after a descriptor of the second given type value. The bytes remaining value is
 199                          *  automatically decremented.
 200                          *
 201                          * \param[in,out] BytesRem       Pointer to the number of bytes remaining of the configuration descriptor.
 202                          * \param[in,out] CurrConfigLoc  Pointer to the current descriptor inside the configuration descriptor.
 203                          * \param[in]     Type           Descriptor type value to search for.
 204                          * \param[in]     AfterType      Descriptor type value which must be reached before the given Type descriptor.
 205                          */
 206                         void USB_GetNextDescriptorOfTypeAfter(uint16_t* const BytesRem,
 207                                                               void** const CurrConfigLoc,
 208                                                               const uint8_t Type,
 209                                                               const uint8_t AfterType)
 210                                                               ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 211
 212                         /** Searches for the next descriptor in the given configuration descriptor using a pre-made comparator
 213                          *  function. The routine updates the position and remaining configuration descriptor bytes values
 214                          *  automatically. If a comparator routine fails a search, the descriptor pointer is retreated back
 215                          *  so that the next descriptor search invocation will start from the descriptor which first caused the
 216                          *  original search to fail. This behavior allows for one comparator to be used immediately after another
 217                          *  has failed, starting the second search from the descriptor which failed the first.
 218                          *
 219                          *  Comparator functions should be standard functions which accept a pointer to the header of the current
 220                          *  descriptor inside the configuration descriptor which is being compared, and should return a value from
 221                          *  the \ref DSearch_Return_ErrorCodes_t enum as a uint8_t value.
 222                          *
 223                          *  \note This function is available in USB Host mode only.
 224                          *
 225                          *  \param[in,out] BytesRem           Pointer to an int storing the remaining bytes in the configuration descriptor.
 226                          *  \param[in,out] CurrConfigLoc      Pointer to the current position in the configuration descriptor.
 227                          *  \param[in]     ComparatorRoutine  Name of the comparator search function to use on the configuration descriptor.
 228                          *
 229                          *  \return Value of one of the members of the \ref DSearch_Comp_Return_ErrorCodes_t enum.
 230                          *
 231                          *  Usage Example:
 232                          *  \code
 233                          *  uint8_t EndpointSearcher(void* CurrentDescriptor); // Comparator Prototype
 234                          *
 235                          *  uint8_t EndpointSearcher(void* CurrentDescriptor)
 236                          *  {
 237                          *     if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Endpoint)
 238                          *         return DESCRIPTOR_SEARCH_Found;
 239                          *     else
 240                          *         return DESCRIPTOR_SEARCH_NotFound;
 241                          *  }
 242                          *
 243                          *  //...
 244                          *
 245                          *  // After retrieving configuration descriptor:
 246                          *  if (USB_Host_GetNextDescriptorComp(&BytesRemaining, &CurrentConfigLoc, EndpointSearcher) ==
 247                          *      Descriptor_Search_Comp_Found)
 248                          *  {
 249                          *      // Do something with the endpoint descriptor
 250                          *  }
 251                          *  \endcode
 252                          */
 253                         uint8_t USB_GetNextDescriptorComp(uint16_t* const BytesRem,
 254                                                           void** const CurrConfigLoc,
 255                                                           ConfigComparatorPtr_t const ComparatorRoutine) ATTR_NON_NULL_PTR_ARG(1)
 256                                                           ATTR_NON_NULL_PTR_ARG(2) ATTR_NON_NULL_PTR_ARG(3);
 257
 258                 /* Inline Functions: */
 259                         /** Skips over the current sub-descriptor inside the configuration descriptor, so that the pointer then
 260                             points to the next sub-descriptor. The bytes remaining value is automatically decremented.
 261                          *
 262                          * \param[in,out] BytesRem       Pointer to the number of bytes remaining of the configuration descriptor.
 263                          * \param[in,out] CurrConfigLoc  Pointer to the current descriptor inside the configuration descriptor.
 264                          */
 265                         static inline void USB_GetNextDescriptor(uint16_t* const BytesRem,
 266                                                                  void** CurrConfigLoc) ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 267                         static inline void USB_GetNextDescriptor(uint16_t* const BytesRem,
 268                                                                  void** CurrConfigLoc)
 269                         {
 270                                 uint16_t CurrDescriptorSize = DESCRIPTOR_CAST(*CurrConfigLoc, USB_Descriptor_Header_t).Size;
 271
 272                                 if (*BytesRem < CurrDescriptorSize)
 273                                   CurrDescriptorSize = *BytesRem;
 274
 275                                 *CurrConfigLoc  = (void*)((uintptr_t)*CurrConfigLoc + CurrDescriptorSize);
 276                                 *BytesRem      -= CurrDescriptorSize;
 277                         }
 278
 279         /* Disable C linkage for C++ Compilers: */
 280                 #if defined(__cplusplus)
 281                         }
 282                 #endif
 283
 284 #endif
 285
 286 /** @} */
 287