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 StillImageHost_GetConfigDescriptorDataCodes_t enum.
  47  */
  48 uint8_t ProcessConfigurationDescriptor(void)
  49 {
  50         uint8_t* ConfigDescriptorData;
  51         uint16_t ConfigDescriptorSize;
  52         uint8_t  FoundEndpoints = 0;
  53
  54         /* Get Configuration Descriptor size from the device */
  55         if (USB_GetDeviceConfigDescriptor(1, &ConfigDescriptorSize, NULL) != HOST_SENDCONTROL_Successful)
  56           return ControlError;
  57
  58         /* Ensure that the Configuration Descriptor isn't too large */
  59         if (ConfigDescriptorSize > MAX_CONFIG_DESCRIPTOR_SIZE)
  60           return DescriptorTooLarge;
  61
  62         /* Allocate enough memory for the entire config descriptor */
  63         ConfigDescriptorData = alloca(ConfigDescriptorSize);
  64
  65         /* Retrieve the entire configuration descriptor into the allocated buffer */
  66         USB_GetDeviceConfigDescriptor(1, &ConfigDescriptorSize, ConfigDescriptorData);
  67
  68         /* Validate returned data - ensure first entry is a configuration header descriptor */
  69         if (DESCRIPTOR_TYPE(ConfigDescriptorData) != DTYPE_Configuration)
  70           return InvalidConfigDataReturned;
  71
  72         /* Get the Still Image interface from the configuration descriptor */
  73         if (USB_GetNextDescriptorComp(&ConfigDescriptorSize, &ConfigDescriptorData,
  74                                       DComp_NextStillImageInterface) != DESCRIPTOR_SEARCH_COMP_Found)
  75         {
  76                 /* Descriptor not found, error out */
  77                 return NoInterfaceFound;
  78         }
  79
  80         /* Get the IN and OUT data and event endpoints for the Still Image interface */
  81         while (FoundEndpoints != ((1 << SIMAGE_EVENTS_PIPE) | (1 << SIMAGE_DATA_IN_PIPE) | (1 << SIMAGE_DATA_OUT_PIPE)))
  82         {
  83                 /* Fetch the next endpoint from the current Still Image interface */
  84                 if (USB_GetNextDescriptorComp(&ConfigDescriptorSize, &ConfigDescriptorData,
  85                                               DComp_NextStillImageInterfaceDataEndpoint) != DESCRIPTOR_SEARCH_COMP_Found)
  86                 {
  87                         /* Descriptor not found, error out */
  88                         return NoEndpointFound;
  89                 }
  90
  91                 USB_Descriptor_Endpoint_t* EndpointData = DESCRIPTOR_PCAST(ConfigDescriptorData, USB_Descriptor_Endpoint_t);
  92
  93                 /* Check if the found endpoint is a interrupt or bulk type descriptor */
  94                 if ((EndpointData->Attributes & EP_TYPE_MASK) == EP_TYPE_INTERRUPT)
  95                 {
  96                         /* If the endpoint is a IN type interrupt endpoint */
  97                         if (EndpointData->EndpointAddress & ENDPOINT_DESCRIPTOR_DIR_IN)
  98                         {
  99                                 /* Configure the events pipe */
 100                                 Pipe_ConfigurePipe(SIMAGE_EVENTS_PIPE, EP_TYPE_INTERRUPT, PIPE_TOKEN_IN,
 101                                                                    EndpointData->EndpointAddress, EndpointData->EndpointSize,
 102                                                                    PIPE_BANK_DOUBLE);
 103
 104                                 Pipe_SetInterruptPeriod(EndpointData->PollingIntervalMS);
 105
 106                                 /* Set the flag indicating that the events pipe has been found */
 107                                 FoundEndpoints |= (1 << SIMAGE_EVENTS_PIPE);
 108                         }
 109                 }
 110                 else
 111                 {
 112                         /* Check if the endpoint is a bulk IN or bulk OUT endpoint */
 113                         if (EndpointData->EndpointAddress & ENDPOINT_DESCRIPTOR_DIR_IN)
 114                         {
 115                                 /* Configure the data IN pipe */
 116                                 Pipe_ConfigurePipe(SIMAGE_DATA_IN_PIPE, EP_TYPE_BULK, PIPE_TOKEN_IN,
 117                                                                    EndpointData->EndpointAddress, EndpointData->EndpointSize,
 118                                                                    PIPE_BANK_DOUBLE);
 119
 120                                 /* Set the flag indicating that the data IN pipe has been found */
 121                                 FoundEndpoints |= (1 << SIMAGE_DATA_IN_PIPE);
 122                         }
 123                         else
 124                         {
 125                                 /* Configure the data OUT pipe */
 126                                 Pipe_ConfigurePipe(SIMAGE_DATA_OUT_PIPE, EP_TYPE_BULK, PIPE_TOKEN_OUT,
 127                                                                    EndpointData->EndpointAddress, EndpointData->EndpointSize,
 128                                                                    PIPE_BANK_DOUBLE);
 129
 130                                 /* Set the flag indicating that the data OUT pipe has been found */
 131                                 FoundEndpoints |= (1 << SIMAGE_DATA_OUT_PIPE);
 132                         }
 133                 }
 134         }
 135
 136         /* Valid data found, return success */
 137         return SuccessfulConfigRead;
 138 }
 139
 140 /** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's
 141  *  configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration
 142  *  descriptor processing if an incompatible descriptor configuration is found.
 143  *
 144  *  This comparator searches for the next Interface descriptor of the correct Still Image Class, Subclass and Protocol values.
 145  *
 146  *  \return A value from the DSEARCH_Return_ErrorCodes_t enum
 147  */
 148 uint8_t DComp_NextStillImageInterface(void* CurrentDescriptor)
 149 {
 150         if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Interface)
 151         {
 152                 /* Check the descriptor class and protocol, break out if correct class/protocol interface found */
 153                 if ((DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).Class    == SIMAGE_CLASS)    &&
 154                     (DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).SubClass == SIMAGE_SUBCLASS) &&
 155                     (DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).Protocol == SIMAGE_PROTOCOL))
 156                 {
 157                         return DESCRIPTOR_SEARCH_Found;
 158                 }
 159         }
 160
 161         return DESCRIPTOR_SEARCH_NotFound;
 162 }
 163
 164 /** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's
 165  *  configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration
 166  *  descriptor processing if an incompatible descriptor configuration is found.
 167  *
 168  *  This comparator searches for the next Interrupt or Bulk Endpoint descriptor of the current SI interface, aborting the
 169  *  search if another interface descriptor is found before the next endpoint.
 170  *
 171  *  \return A value from the DSEARCH_Return_ErrorCodes_t enum
 172  */
 173 uint8_t DComp_NextStillImageInterfaceDataEndpoint(void* CurrentDescriptor)
 174 {
 175         if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Endpoint)
 176         {
 177                 uint8_t EndpointType = (DESCRIPTOR_CAST(CurrentDescriptor,
 178                                                         USB_Descriptor_Endpoint_t).Attributes & EP_TYPE_MASK);
 179
 180                 if ((EndpointType == EP_TYPE_BULK) || (EndpointType == EP_TYPE_INTERRUPT))
 181                   return DESCRIPTOR_SEARCH_Found;
 182         }
 183         else if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Interface)
 184         {
 185                 return DESCRIPTOR_SEARCH_Fail;
 186         }
 187
 188         return DESCRIPTOR_SEARCH_NotFound;
 189 }