Demos/Host/LowLevel/StillImageHost/ConfigDescriptor.c

   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  *  USB Device Configuration Descriptor processing routines, to determine the correct pipe configurations
  34  *  needed to communication with an attached USB device. Descriptors are special  computer-readable structures
  35  *  which the host requests upon device enumeration, to determine the device's capabilities and functions.
  36  */
  37
  38 #include "ConfigDescriptor.h"
  39
  40 /** Reads and processes an attached device's descriptors, to determine compatibility and pipe configurations. This
  41  *  routine will read in the entire configuration descriptor, and configure the hosts pipes to correctly communicate
  42  *  with compatible devices.
  43  *
  44  *  This routine searches for a SI interface descriptor containing bulk IN and OUT data endpoints.
  45  *
  46  *  \return An error code from the \ref StillImageHost_GetConfigDescriptorDataCodes_t enum.
  47  */
  48 uint8_t ProcessConfigurationDescriptor(void)
  49 {
  50         uint8_t  ConfigDescriptorData[512];
  51         void*    CurrConfigLocation = ConfigDescriptorData;
  52         uint16_t CurrConfigBytesRem;
  53         uint8_t  FoundEndpoints = 0;
  54
  55         /* Retrieve the entire configuration descriptor into the allocated buffer */
  56         switch (USB_Host_GetDeviceConfigDescriptor(1, &CurrConfigBytesRem, ConfigDescriptorData, sizeof(ConfigDescriptorData)))
  57         {
  58                 case HOST_GETCONFIG_Successful:
  59                         break;
  60                 case HOST_GETCONFIG_InvalidData:
  61                         return InvalidConfigDataReturned;
  62                 case HOST_GETCONFIG_BuffOverflow:
  63                         return DescriptorTooLarge;
  64                 default:
  65                         return ControlError;
  66         }
  67
  68         /* Get the Still Image interface from the configuration descriptor */
  69         if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
  70                                       DComp_NextStillImageInterface) != DESCRIPTOR_SEARCH_COMP_Found)
  71         {
  72                 /* Descriptor not found, error out */
  73                 return NoInterfaceFound;
  74         }
  75
  76         /* Get the IN and OUT data and event endpoints for the Still Image interface */
  77         while (FoundEndpoints != ((1 << SIMAGE_EVENTS_PIPE) | (1 << SIMAGE_DATA_IN_PIPE) | (1 << SIMAGE_DATA_OUT_PIPE)))
  78         {
  79                 /* Fetch the next endpoint from the current Still Image interface */
  80                 if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
  81                                               DComp_NextStillImageInterfaceDataEndpoint) != DESCRIPTOR_SEARCH_COMP_Found)
  82                 {
  83                         /* Descriptor not found, error out */
  84                         return NoEndpointFound;
  85                 }
  86
  87                 USB_Descriptor_Endpoint_t* EndpointData = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Endpoint_t);
  88
  89                 /* Check if the found endpoint is a interrupt or bulk type descriptor */
  90                 if ((EndpointData->Attributes & EP_TYPE_MASK) == EP_TYPE_INTERRUPT)
  91                 {
  92                         /* If the endpoint is a IN type interrupt endpoint */
  93                         if (EndpointData->EndpointAddress & ENDPOINT_DESCRIPTOR_DIR_IN)
  94                         {
  95                                 /* Configure the events pipe */
  96                                 Pipe_ConfigurePipe(SIMAGE_EVENTS_PIPE, EP_TYPE_INTERRUPT, PIPE_TOKEN_IN,
  97                                                                    EndpointData->EndpointAddress, EndpointData->EndpointSize,
  98                                                                    PIPE_BANK_DOUBLE);
  99
 100                                 Pipe_SetInterruptPeriod(EndpointData->PollingIntervalMS);
 101
 102                                 /* Set the flag indicating that the events pipe has been found */
 103                                 FoundEndpoints |= (1 << SIMAGE_EVENTS_PIPE);
 104                         }
 105                 }
 106                 else
 107                 {
 108                         /* Check if the endpoint is a bulk IN or bulk OUT endpoint */
 109                         if (EndpointData->EndpointAddress & ENDPOINT_DESCRIPTOR_DIR_IN)
 110                         {
 111                                 /* Configure the data IN pipe */
 112                                 Pipe_ConfigurePipe(SIMAGE_DATA_IN_PIPE, EP_TYPE_BULK, PIPE_TOKEN_IN,
 113                                                                    EndpointData->EndpointAddress, EndpointData->EndpointSize,
 114                                                                    PIPE_BANK_DOUBLE);
 115
 116                                 /* Set the flag indicating that the data IN pipe has been found */
 117                                 FoundEndpoints |= (1 << SIMAGE_DATA_IN_PIPE);
 118                         }
 119                         else
 120                         {
 121                                 /* Configure the data OUT pipe */
 122                                 Pipe_ConfigurePipe(SIMAGE_DATA_OUT_PIPE, EP_TYPE_BULK, PIPE_TOKEN_OUT,
 123                                                                    EndpointData->EndpointAddress, EndpointData->EndpointSize,
 124                                                                    PIPE_BANK_DOUBLE);
 125
 126                                 /* Set the flag indicating that the data OUT pipe has been found */
 127                                 FoundEndpoints |= (1 << SIMAGE_DATA_OUT_PIPE);
 128                         }
 129                 }
 130         }
 131
 132         /* Valid data found, return success */
 133         return SuccessfulConfigRead;
 134 }
 135
 136 /** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's
 137  *  configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration
 138  *  descriptor processing if an incompatible descriptor configuration is found.
 139  *
 140  *  This comparator searches for the next Interface descriptor of the correct Still Image Class, Subclass and Protocol values.
 141  *
 142  *  \return A value from the DSEARCH_Return_ErrorCodes_t enum
 143  */
 144 uint8_t DComp_NextStillImageInterface(void* CurrentDescriptor)
 145 {
 146         if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Interface)
 147         {
 148                 /* Check the descriptor class and protocol, break out if correct class/protocol interface found */
 149                 if ((DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).Class    == SIMAGE_CLASS)    &&
 150                     (DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).SubClass == SIMAGE_SUBCLASS) &&
 151                     (DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).Protocol == SIMAGE_PROTOCOL))
 152                 {
 153                         return DESCRIPTOR_SEARCH_Found;
 154                 }
 155         }
 156
 157         return DESCRIPTOR_SEARCH_NotFound;
 158 }
 159
 160 /** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's
 161  *  configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration
 162  *  descriptor processing if an incompatible descriptor configuration is found.
 163  *
 164  *  This comparator searches for the next Interrupt or Bulk Endpoint descriptor of the current SI interface, aborting the
 165  *  search if another interface descriptor is found before the next endpoint.
 166  *
 167  *  \return A value from the DSEARCH_Return_ErrorCodes_t enum
 168  */
 169 uint8_t DComp_NextStillImageInterfaceDataEndpoint(void* CurrentDescriptor)
 170 {
 171         if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Endpoint)
 172         {
 173                 uint8_t EndpointType = (DESCRIPTOR_CAST(CurrentDescriptor,
 174                                                         USB_Descriptor_Endpoint_t).Attributes & EP_TYPE_MASK);
 175
 176                 if ((EndpointType == EP_TYPE_BULK) || (EndpointType == EP_TYPE_INTERRUPT))
 177                   return DESCRIPTOR_SEARCH_Found;
 178         }
 179         else if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Interface)
 180         {
 181                 return DESCRIPTOR_SEARCH_Fail;
 182         }
 183
 184         return DESCRIPTOR_SEARCH_NotFound;
 185 }