LUFA/Drivers/USB/HighLevel/ConfigDescriptor.h

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2010.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6       www.fourwalledcubicle.com
   7 */
   8
   9 /*
  10   Copyright 2010  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  *
  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         /* Preprocessor Checks: */
  63                 #if !defined(__INCLUDE_FROM_USB_DRIVER)
  64                         #error Do not include this file directly. Include LUFA/Drivers/USB.h instead.
  65                 #endif
  66
  67         /* Public Interface - May be used in end-application: */
  68                 /* Macros: */
  69                         /** Mask for determining the type of an endpoint from an endpoint descriptor. This should then be compared
  70                          *  with the EP_TYPE_* masks to determine the exact type of the endpoint.
  71                          */
  72                         #define EP_TYPE_MASK                       0x03
  73
  74                         /** Casts a pointer to a descriptor inside the configuration descriptor into a pointer to the given
  75                          *  descriptor type.
  76                          *
  77                          *  Usage Example:
  78                          *  \code
  79                          *  uint8_t* CurrDescriptor = &ConfigDescriptor[0]; // Pointing to the configuration header
  80                          *  USB_Descriptor_Configuration_Header_t* ConfigHeaderPtr = DESCRIPTOR_PCAST(CurrDescriptor,
  81                          *                                                           USB_Descriptor_Configuration_Header_t);
  82                          *
  83                          *  // Can now access elements of the configuration header struct using the -> indirection operator
  84                          *  \endcode
  85                          */
  86                         #define DESCRIPTOR_PCAST(DescriptorPtr, Type) ((Type*)(DescriptorPtr))
  87
  88                         /** Casts a pointer to a descriptor inside the configuration descriptor into the given descriptor
  89                          *  type (as an actual struct instance rather than a pointer to a struct).
  90                          *
  91                          *  Usage Example:
  92                          *  \code
  93                          *  uint8_t* CurrDescriptor = &ConfigDescriptor[0]; // Pointing to the configuration header
  94                          *  USB_Descriptor_Configuration_Header_t ConfigHeader = DESCRIPTOR_CAST(CurrDescriptor,
  95                          *                                                       USB_Descriptor_Configuration_Header_t);
  96                          *
  97                          *  // Can now access elements of the configuration header struct using the . operator
  98                          *  \endcode
  99                          */
 100                         #define DESCRIPTOR_CAST(DescriptorPtr, Type)  (*DESCRIPTOR_PCAST(DescriptorPtr, Type))
 101
 102                         /** Returns the descriptor's type, expressed as the 8-bit type value in the header of the descriptor.
 103                          *  This value's meaning depends on the descriptor's placement in the descriptor, but standard type
 104                          *  values can be accessed in the \ref USB_DescriptorTypes_t enum.
 105                          */
 106                         #define DESCRIPTOR_TYPE(DescriptorPtr)    DESCRIPTOR_CAST(DescriptorPtr, USB_Descriptor_Header_t).Type
 107
 108                         /** Returns the descriptor's size, expressed as the 8-bit value indicating the number of bytes. */
 109                         #define DESCRIPTOR_SIZE(DescriptorPtr)    DESCRIPTOR_CAST(DescriptorPtr, USB_Descriptor_Header_t).Size
 110
 111                 /* Type Defines: */
 112                         /** Type define for a Configuration Descriptor comparator function (function taking a pointer to an array
 113                          *  of type void, returning a uint8_t value).
 114                          *
 115                          *  \see \ref USB_GetNextDescriptorComp function for more details
 116                          */
 117                         typedef uint8_t (* const ConfigComparatorPtr_t)(void*);
 118
 119                 /* Function Prototypes: */
 120                         /** Searches for the next descriptor in the given configuration descriptor using a premade comparator
 121                          *  function. The routine updates the position and remaining configuration descriptor bytes values
 122                          *  automatically. If a comparator routine fails a search, the descriptor pointer is retreated back
 123                          *  so that the next descriptor search invocation will start from the descriptor which first caused the
 124                          *  original search to fail. This behaviour allows for one comparator to be used immediately after another
 125                          *  has failed, starting the second search from the descriptor which failed the first.
 126                          *
 127                          *  Comparator functions should be standard functions which accept a pointer to the header of the current
 128                          *  descriptor inside the configuration descriptor which is being compared, and should return a value from
 129                          *  the \ref DSearch_Return_ErrorCodes_t enum as a uint8_t value.
 130                          *
 131                          *  \note This function is available in USB Host mode only.
 132                          *
 133                          *  \param[in,out] BytesRem  Pointer to an int storing the remaining bytes in the configuration descriptor
 134                          *  \param[in,out] CurrConfigLoc  Pointer to the current position in the configuration descriptor
 135                          *  \param[in] ComparatorRoutine  Name of the comparator search function to use on the configuration descriptor
 136                          *
 137                          *  \return Value of one of the members of the \ref DSearch_Comp_Return_ErrorCodes_t enum
 138                          *
 139                          *  Usage Example:
 140                          *  \code
 141                          *  uint8_t EndpointSearcher(void* CurrentDescriptor); // Comparator Prototype
 142                          *
 143                          *  uint8_t EndpointSearcher(void* CurrentDescriptor)
 144                          *  {
 145                          *     if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Endpoint)
 146                          *         return DESCRIPTOR_SEARCH_Found;
 147                          *     else
 148                          *         return DESCRIPTOR_SEARCH_NotFound;
 149                          *  }
 150                          *
 151                          *  //...
 152                          *  // After retrieving configuration descriptor:
 153                          *  if (USB_Host_GetNextDescriptorComp(&BytesRemaining, &CurrentConfigLoc, EndpointSearcher) ==
 154                          *      Descriptor_Search_Comp_Found)
 155                          *  {
 156                          *      // Do something with the endpoint descriptor
 157                          *  }
 158                          *  \endcode
 159                          */
 160                         uint8_t USB_GetNextDescriptorComp(uint16_t* BytesRem, void** CurrConfigLoc, ConfigComparatorPtr_t ComparatorRoutine);
 161
 162                 /* Enums: */
 163                         /** Enum for the possible return codes of the \ref USB_Host_GetDeviceConfigDescriptor() function. */
 164                         enum USB_Host_GetConfigDescriptor_ErrorCodes_t
 165                         {
 166                                 HOST_GETCONFIG_Successful       = 0, /**< No error occurred while retrieving the configuration descriptor */
 167                                 HOST_GETCONFIG_DeviceDisconnect = 1, /**< The attached device was disconnected while retrieving the configuration
 168                                                                         * descriptor
 169                                                                         */
 170                                 HOST_GETCONFIG_PipeError        = 2, /**< An error occurred in the pipe while sending the request */
 171                                 HOST_GETCONFIG_SetupStalled     = 3, /**< The attached device stalled the request to retrieve the configuration
 172                                                                         * descriptor
 173                                                                         */
 174                                 HOST_GETCONFIG_SoftwareTimeOut  = 4, /**< The request or data transfer timed out */
 175                                 HOST_GETCONFIG_BuffOverflow     = 5, /**< The device's configuration descriptor is too large to fit into the allocated
 176                                                                         * buffer
 177                                                                         */
 178                                 HOST_GETCONFIG_InvalidData      = 6, /**< The device returned invalid configuration descriptor data */
 179                         };
 180
 181                         /** Enum for return values of a descriptor comparator function. */
 182                         enum DSearch_Return_ErrorCodes_t
 183                         {
 184                                 DESCRIPTOR_SEARCH_Found                = 0, /**< Current descriptor matches comparator criteria. */
 185                                 DESCRIPTOR_SEARCH_Fail                 = 1, /**< No further descriptor could possibly match criteria, fail the search. */
 186                                 DESCRIPTOR_SEARCH_NotFound             = 2, /**< Current descriptor does not match comparator criteria. */
 187                         };
 188
 189                         /** Enum for return values of \ref USB_GetNextDescriptorComp(). */
 190                         enum DSearch_Comp_Return_ErrorCodes_t
 191                         {
 192                                 DESCRIPTOR_SEARCH_COMP_Found           = 0, /**< Configuration descriptor now points to descriptor which matches
 193                                                                              *   search criteria of the given comparator function. */
 194                                 DESCRIPTOR_SEARCH_COMP_Fail            = 1, /**< Comparator function returned Descriptor_Search_Fail. */
 195                                 DESCRIPTOR_SEARCH_COMP_EndOfDescriptor = 2, /**< End of configuration descriptor reached before match found. */
 196                         };
 197
 198                 /* Function Prototypes: */
 199                         /** Retrieves the configuration descriptor data from an attached device via a standard request into a buffer,
 200                          *  including validity and size checking to prevent a buffer overflow.
 201                          *
 202                          *  \param[in] ConfigNumber  Device configuration descriptor number to fetch from the device (usually set to 1 for
 203                          *                           single configuration devices)
 204                          *  \param[in,out] ConfigSizePtr  Pointer to a uint16_t for storing the retrieved configuration descriptor size
 205                          *  \param[out] BufferPtr  Pointer to the buffer for storing the configuration descriptor data.
 206                          *  \param[out] BufferSize  Size of the allocated buffer where the configuration descriptor is to be stored
 207                          *
 208                          *  \return A value from the \ref USB_Host_GetConfigDescriptor_ErrorCodes_t enum
 209                          */
 210                         uint8_t USB_Host_GetDeviceConfigDescriptor(uint8_t ConfigNumber, uint16_t* const ConfigSizePtr, void* BufferPtr,
 211                                                                    uint16_t BufferSize) ATTR_NON_NULL_PTR_ARG(2) ATTR_NON_NULL_PTR_ARG(3);
 212
 213                         /** Skips to the next sub-descriptor inside the configuration descriptor of the specified type value.
 214                          *  The bytes remaining value is automatically decremented.
 215                          *
 216                          * \param[in,out] BytesRem  Pointer to the number of bytes remaining of the configuration descriptor
 217                          * \param[in,out] CurrConfigLoc  Pointer to the current descriptor inside the configuration descriptor
 218                          * \param[in] Type  Descriptor type value to search for
 219                          */
 220                         void USB_GetNextDescriptorOfType(uint16_t* const BytesRem,
 221                                                          void** const CurrConfigLoc,
 222                                                          const uint8_t Type)
 223                                                          ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 224
 225                         /** Skips to the next sub-descriptor inside the configuration descriptor of the specified type value,
 226                          *  which must come before a descriptor of the second given type value. If the BeforeType type
 227                          *  descriptor is reached first, the number of bytes remaining to process is set to zero and the
 228                          *  function exits. The bytes remaining value is automatically decremented.
 229                          *
 230                          * \param[in,out] BytesRem  Pointer to the number of bytes remaining of the configuration descriptor
 231                          * \param[in,out] CurrConfigLoc  Pointer to the current descriptor inside the configuration descriptor
 232                          * \param[in] Type  Descriptor type value to search for
 233                          * \param[in] BeforeType  Descriptor type value which must not be reached before the given Type descriptor
 234                          */
 235                         void USB_GetNextDescriptorOfTypeBefore(uint16_t* const BytesRem,
 236                                                                void** const CurrConfigLoc,
 237                                                                const uint8_t Type,
 238                                                                const uint8_t BeforeType)
 239                                                                ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 240
 241                         /** Skips to the next sub-descriptor inside the configuration descriptor of the specified type value,
 242                          *  which must come after a descriptor of the second given type value. The bytes remaining value is
 243                          *  automatically decremented.
 244                          *
 245                          * \param[in,out] BytesRem  Pointer to the number of bytes remaining of the configuration descriptor
 246                          * \param[in,out] CurrConfigLoc  Pointer to the current descriptor inside the configuration descriptor
 247                          * \param[in] Type  Descriptor type value to search for
 248                          * \param[in] AfterType  Descriptor type value which must be reached before the given Type descriptor
 249                          */
 250                         void USB_GetNextDescriptorOfTypeAfter(uint16_t* const BytesRem,
 251                                                               void** const CurrConfigLoc,
 252                                                               const uint8_t Type,
 253                                                               const uint8_t AfterType)
 254                                                               ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 255
 256                 /* Inline Functions: */
 257                         /** Skips over the current sub-descriptor inside the configuration descriptor, so that the pointer then
 258                             points to the next sub-descriptor. The bytes remaining value is automatically decremented.
 259                          *
 260                          * \param[in,out] BytesRem  Pointer to the number of bytes remaining of the configuration descriptor
 261                          * \param[in,out] CurrConfigLoc  Pointer to the current descriptor inside the configuration descriptor
 262                          */
 263                         static inline void USB_GetNextDescriptor(uint16_t* const BytesRem,
 264                                                                  void** const CurrConfigLoc)
 265                                                                  ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 266                         static inline void USB_GetNextDescriptor(uint16_t* const BytesRem,
 267                                                                  void** const CurrConfigLoc)
 268                         {
 269                                 uint16_t CurrDescriptorSize = DESCRIPTOR_CAST(*CurrConfigLoc, USB_Descriptor_Header_t).Size;
 270
 271                                 *CurrConfigLoc += CurrDescriptorSize;
 272                                 *BytesRem      -= CurrDescriptorSize;
 273                         }
 274
 275         /* Disable C linkage for C++ Compilers: */
 276                 #if defined(__cplusplus)
 277                         }
 278                 #endif
 279
 280 #endif
 281
 282 /** @} */