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  *  \brief Configuration descriptor parser API.
  33  *
  34  *  This section of the library gives a friendly API which can be used in host applications to easily
  35  *  parse an attached device's configuration descriptor so that endpoint, interface and other descriptor
  36  *  data can be extracted and used as needed.
  37  *
  38  *  \note This file should not be included directly. It is automatically included as needed by the USB driver
  39  *        dispatch header located in LUFA/Drivers/USB/USB.h.
  40  */
  41
  42 /** \ingroup Group_Descriptors
  43  *  @defgroup Group_ConfigDescriptorParser Configuration Descriptor Parser
  44  *
  45  *  Functions, macros, variables, enums and types related to the parsing of Configuration Descriptors.
  46  *
  47  *  @{
  48  */
  49
  50 #ifndef __CONFIGDESCRIPTOR_H__
  51 #define __CONFIGDESCRIPTOR_H__
  52
  53         /* Includes: */
  54                 #include <avr/io.h>
  55
  56                 #include "../../../Common/Common.h"
  57                 #include "../HighLevel/USBMode.h"
  58                 #include "../LowLevel/HostChapter9.h"
  59                 #include "../HighLevel/StdDescriptors.h"
  60
  61         /* Enable C linkage for C++ Compilers: */
  62                 #if defined(__cplusplus)
  63                         extern "C" {
  64                 #endif
  65
  66         /* Preprocessor Checks: */
  67                 #if !defined(__INCLUDE_FROM_USB_DRIVER)
  68                         #error Do not include this file directly. Include LUFA/Drivers/USB/USB.h instead.
  69                 #endif
  70
  71         /* Public Interface - May be used in end-application: */
  72                 /* Macros: */
  73                         /** Mask for determining the type of an endpoint from an endpoint descriptor. This should then be compared
  74                          *  with the EP_TYPE_* masks to determine the exact type of the endpoint.
  75                          */
  76                         #define EP_TYPE_MASK                       0x03
  77
  78                         /** Casts a pointer to a descriptor inside the configuration descriptor into a pointer to the given
  79                          *  descriptor type.
  80                          *
  81                          *  Usage Example:
  82                          *  \code
  83                          *  uint8_t* CurrDescriptor = &ConfigDescriptor[0]; // Pointing to the configuration header
  84                          *  USB_Descriptor_Configuration_Header_t* ConfigHeaderPtr = DESCRIPTOR_PCAST(CurrDescriptor,
  85                          *                                                           USB_Descriptor_Configuration_Header_t);
  86                          *
  87                          *  // Can now access elements of the configuration header struct using the -> indirection operator
  88                          *  \endcode
  89                          */
  90                         #define DESCRIPTOR_PCAST(DescriptorPtr, Type) ((Type*)(DescriptorPtr))
  91
  92                         /** Casts a pointer to a descriptor inside the configuration descriptor into the given descriptor
  93                          *  type (as an actual struct instance rather than a pointer to a struct).
  94                          *
  95                          *  Usage Example:
  96                          *  \code
  97                          *  uint8_t* CurrDescriptor = &ConfigDescriptor[0]; // Pointing to the configuration header
  98                          *  USB_Descriptor_Configuration_Header_t ConfigHeader = DESCRIPTOR_CAST(CurrDescriptor,
  99                          *                                                       USB_Descriptor_Configuration_Header_t);
 100                          *
 101                          *  // Can now access elements of the configuration header struct using the . operator
 102                          *  \endcode
 103                          */
 104                         #define DESCRIPTOR_CAST(DescriptorPtr, Type)  (*DESCRIPTOR_PCAST(DescriptorPtr, Type))
 105
 106                         /** Returns the descriptor's type, expressed as the 8-bit type value in the header of the descriptor.
 107                          *  This value's meaning depends on the descriptor's placement in the descriptor, but standard type
 108                          *  values can be accessed in the \ref USB_DescriptorTypes_t enum.
 109                          */
 110                         #define DESCRIPTOR_TYPE(DescriptorPtr)    DESCRIPTOR_CAST(DescriptorPtr, USB_Descriptor_Header_t).Type
 111
 112                         /** Returns the descriptor's size, expressed as the 8-bit value indicating the number of bytes. */
 113                         #define DESCRIPTOR_SIZE(DescriptorPtr)    DESCRIPTOR_CAST(DescriptorPtr, USB_Descriptor_Header_t).Size
 114
 115                 /* Type Defines: */
 116                         /** Type define for a Configuration Descriptor comparator function (function taking a pointer to an array
 117                          *  of type void, returning a uint8_t value).
 118                          *
 119                          *  \see \ref USB_GetNextDescriptorComp function for more details
 120                          */
 121                         typedef uint8_t (* const ConfigComparatorPtr_t)(void*);
 122
 123                 /* Function Prototypes: */
 124                         /** Searches for the next descriptor in the given configuration descriptor using a premade comparator
 125                          *  function. The routine updates the position and remaining configuration descriptor bytes values
 126                          *  automatically. If a comparator routine fails a search, the descriptor pointer is retreated back
 127                          *  so that the next descriptor search invocation will start from the descriptor which first caused the
 128                          *  original search to fail. This behaviour allows for one comparator to be used immediately after another
 129                          *  has failed, starting the second search from the descriptor which failed the first.
 130                          *
 131                          *  Comparator functions should be standard functions which accept a pointer to the header of the current
 132                          *  descriptor inside the configuration descriptor which is being compared, and should return a value from
 133                          *  the \ref DSearch_Return_ErrorCodes_t enum as a uint8_t value.
 134                          *
 135                          *  \note This function is available in USB Host mode only.
 136                          *
 137                          *  \param[in,out] BytesRem  Pointer to an int storing the remaining bytes in the configuration descriptor
 138                          *  \param[in,out] CurrConfigLoc  Pointer to the current position in the configuration descriptor
 139                          *  \param[in] ComparatorRoutine  Name of the comparator search function to use on the configuration descriptor
 140                          *
 141                          *  \return Value of one of the members of the \ref DSearch_Comp_Return_ErrorCodes_t enum
 142                          *
 143                          *  Usage Example:
 144                          *  \code
 145                          *  uint8_t EndpointSearcher(void* CurrentDescriptor); // Comparator Prototype
 146                          *
 147                          *  uint8_t EndpointSearcher(void* CurrentDescriptor)
 148                          *  {
 149                          *     if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Endpoint)
 150                          *         return DESCRIPTOR_SEARCH_Found;
 151                          *     else
 152                          *         return DESCRIPTOR_SEARCH_NotFound;
 153                          *  }
 154                          *
 155                          *  //...
 156                          *  // After retrieving configuration descriptor:
 157                          *  if (USB_Host_GetNextDescriptorComp(&BytesRemaining, &CurrentConfigLoc, EndpointSearcher) ==
 158                          *      Descriptor_Search_Comp_Found)
 159                          *  {
 160                          *      // Do something with the endpoint descriptor
 161                          *  }
 162                          *  \endcode
 163                          */
 164                         uint8_t USB_GetNextDescriptorComp(uint16_t* BytesRem, void** CurrConfigLoc, ConfigComparatorPtr_t ComparatorRoutine);
 165
 166                 /* Enums: */
 167                         /** Enum for the possible return codes of the \ref USB_Host_GetDeviceConfigDescriptor() function. */
 168                         enum USB_Host_GetConfigDescriptor_ErrorCodes_t
 169                         {
 170                                 HOST_GETCONFIG_Successful       = 0, /**< No error occurred while retrieving the configuration descriptor */
 171                                 HOST_GETCONFIG_DeviceDisconnect = 1, /**< The attached device was disconnected while retrieving the configuration
 172                                                                         * descriptor
 173                                                                         */
 174                                 HOST_GETCONFIG_PipeError        = 2, /**< An error occurred in the pipe while sending the request */
 175                                 HOST_GETCONFIG_SetupStalled     = 3, /**< The attached device stalled the request to retrieve the configuration
 176                                                                         * descriptor
 177                                                                         */
 178                                 HOST_GETCONFIG_SoftwareTimeOut  = 4, /**< The request or data transfer timed out */
 179                                 HOST_GETCONFIG_BuffOverflow     = 5, /**< The device's configuration descriptor is too large to fit into the allocated
 180                                                                         * buffer
 181                                                                         */
 182                                 HOST_GETCONFIG_InvalidData      = 6, /**< The device returned invalid configuration descriptor data */
 183                         };
 184
 185                         /** Enum for return values of a descriptor comparator function. */
 186                         enum DSearch_Return_ErrorCodes_t
 187                         {
 188                                 DESCRIPTOR_SEARCH_Found                = 0, /**< Current descriptor matches comparator criteria. */
 189                                 DESCRIPTOR_SEARCH_Fail                 = 1, /**< No further descriptor could possibly match criteria, fail the search. */
 190                                 DESCRIPTOR_SEARCH_NotFound             = 2, /**< Current descriptor does not match comparator criteria. */
 191                         };
 192
 193                         /** Enum for return values of \ref USB_GetNextDescriptorComp(). */
 194                         enum DSearch_Comp_Return_ErrorCodes_t
 195                         {
 196                                 DESCRIPTOR_SEARCH_COMP_Found           = 0, /**< Configuration descriptor now points to descriptor which matches
 197                                                                              *   search criteria of the given comparator function. */
 198                                 DESCRIPTOR_SEARCH_COMP_Fail            = 1, /**< Comparator function returned Descriptor_Search_Fail. */
 199                                 DESCRIPTOR_SEARCH_COMP_EndOfDescriptor = 2, /**< End of configuration descriptor reached before match found. */
 200                         };
 201
 202                 /* Function Prototypes: */
 203                         /** Retrieves the configuration descriptor data from an attached device via a standard request into a buffer,
 204                          *  including validity and size checking to prevent a buffer overflow.
 205                          *
 206                          *  \param[in] ConfigNumber  Device configuration descriptor number to fetch from the device (usually set to 1 for
 207                          *                           single configuration devices)
 208                          *  \param[in,out] ConfigSizePtr  Pointer to a uint16_t for storing the retrieved configuration descriptor size
 209                          *  \param[out] BufferPtr  Pointer to the buffer for storing the configuration descriptor data.
 210                          *  \param[out] BufferSize  Size of the allocated buffer where the configuration descriptor is to be stored
 211                          *
 212                          *  \return A value from the \ref USB_Host_GetConfigDescriptor_ErrorCodes_t enum
 213                          */
 214                         uint8_t USB_Host_GetDeviceConfigDescriptor(uint8_t ConfigNumber, uint16_t* const ConfigSizePtr, void* BufferPtr,
 215                                                                    uint16_t BufferSize) ATTR_NON_NULL_PTR_ARG(2) ATTR_NON_NULL_PTR_ARG(3);
 216
 217                         /** Skips to the next sub-descriptor inside the configuration descriptor of the specified type value.
 218                          *  The bytes remaining value is automatically decremented.
 219                          *
 220                          * \param[in,out] BytesRem  Pointer to the number of bytes remaining of the configuration descriptor
 221                          * \param[in,out] CurrConfigLoc  Pointer to the current descriptor inside the configuration descriptor
 222                          * \param[in] Type  Descriptor type value to search for
 223                          */
 224                         void USB_GetNextDescriptorOfType(uint16_t* const BytesRem,
 225                                                          void** const CurrConfigLoc,
 226                                                          const uint8_t Type)
 227                                                          ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 228
 229                         /** Skips to the next sub-descriptor inside the configuration descriptor of the specified type value,
 230                          *  which must come before a descriptor of the second given type value. If the BeforeType type
 231                          *  descriptor is reached first, the number of bytes remaining to process is set to zero and the
 232                          *  function exits. The bytes remaining value is automatically decremented.
 233                          *
 234                          * \param[in,out] BytesRem  Pointer to the number of bytes remaining of the configuration descriptor
 235                          * \param[in,out] CurrConfigLoc  Pointer to the current descriptor inside the configuration descriptor
 236                          * \param[in] Type  Descriptor type value to search for
 237                          * \param[in] BeforeType  Descriptor type value which must not be reached before the given Type descriptor
 238                          */
 239                         void USB_GetNextDescriptorOfTypeBefore(uint16_t* const BytesRem,
 240                                                                void** const CurrConfigLoc,
 241                                                                const uint8_t Type,
 242                                                                const uint8_t BeforeType)
 243                                                                ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 244
 245                         /** Skips to the next sub-descriptor inside the configuration descriptor of the specified type value,
 246                          *  which must come after a descriptor of the second given type value. The bytes remaining value is
 247                          *  automatically decremented.
 248                          *
 249                          * \param[in,out] BytesRem  Pointer to the number of bytes remaining of the configuration descriptor
 250                          * \param[in,out] CurrConfigLoc  Pointer to the current descriptor inside the configuration descriptor
 251                          * \param[in] Type  Descriptor type value to search for
 252                          * \param[in] AfterType  Descriptor type value which must be reached before the given Type descriptor
 253                          */
 254                         void USB_GetNextDescriptorOfTypeAfter(uint16_t* const BytesRem,
 255                                                               void** const CurrConfigLoc,
 256                                                               const uint8_t Type,
 257                                                               const uint8_t AfterType)
 258                                                               ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 259
 260                 /* Inline Functions: */
 261                         /** Skips over the current sub-descriptor inside the configuration descriptor, so that the pointer then
 262                             points to the next sub-descriptor. The bytes remaining value is automatically decremented.
 263                          *
 264                          * \param[in,out] BytesRem  Pointer to the number of bytes remaining of the configuration descriptor
 265                          * \param[in,out] CurrConfigLoc  Pointer to the current descriptor inside the configuration descriptor
 266                          */
 267                         static inline void USB_GetNextDescriptor(uint16_t* const BytesRem,
 268                                                                  void** const CurrConfigLoc)
 269                                                                  ATTR_NON_NULL_PTR_ARG(1) ATTR_NON_NULL_PTR_ARG(2);
 270                         static inline void USB_GetNextDescriptor(uint16_t* const BytesRem,
 271                                                                  void** const CurrConfigLoc)
 272                         {
 273                                 uint16_t CurrDescriptorSize = DESCRIPTOR_CAST(*CurrConfigLoc, USB_Descriptor_Header_t).Size;
 274
 275                                 *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 /** @} */