Demos/Host/LowLevel/RNDISEthernetHost/ConfigDescriptor.c

   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  *  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 RNDIS interface descriptor containing bulk data IN and OUT endpoints, and an interrupt event endpoint.
  45  *
  46  *  \return An error code from the \ref RNDISHost_GetConfigDescriptorDataCodes_t enum.
  47  */
  48 uint8_t ProcessConfigurationDescriptor(void)
  49 {
  50         uint8_t  ConfigDescriptorData[512];
  51         void*    CurrConfigLocation = ConfigDescriptorData;
  52         uint16_t CurrConfigBytesRem;
  53
  54         USB_Descriptor_Endpoint_t* DataINEndpoint       = NULL;
  55         USB_Descriptor_Endpoint_t* DataOUTEndpoint      = NULL;
  56         USB_Descriptor_Endpoint_t* NotificationEndpoint = NULL;
  57
  58         /* Retrieve the entire configuration descriptor into the allocated buffer */
  59         switch (USB_Host_GetDeviceConfigDescriptor(1, &CurrConfigBytesRem, ConfigDescriptorData, sizeof(ConfigDescriptorData)))
  60         {
  61                 case HOST_GETCONFIG_Successful:
  62                         break;
  63                 case HOST_GETCONFIG_InvalidData:
  64                         return InvalidConfigDataReturned;
  65                 case HOST_GETCONFIG_BuffOverflow:
  66                         return DescriptorTooLarge;
  67                 default:
  68                         return ControlError;
  69         }
  70
  71         /* Get the first RNDIS control interface from the configuration descriptor */
  72         if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
  73                                       DComp_NextCDCControlInterface) != DESCRIPTOR_SEARCH_COMP_Found)
  74         {
  75                 /* Descriptor not found, error out */
  76                 return NoCompatibleInterfaceFound;
  77         }
  78
  79         while (!(DataINEndpoint) || !(DataOUTEndpoint) || !(NotificationEndpoint))
  80         {
  81                 /* Get the next RNDIS interface's endpoint descriptor */
  82                 if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
  83                                               DComp_NextCDCDataInterfaceEndpoint) != DESCRIPTOR_SEARCH_COMP_Found)
  84                 {
  85                         /* Check if we have already found the control interface's notification endpoint or not */
  86                         if (NotificationEndpoint)
  87                         {
  88                                 /* Get the next RNDIS data interface from the configuration descriptor */
  89                                 if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
  90                                                                                           DComp_NextCDCDataInterface) != DESCRIPTOR_SEARCH_COMP_Found)
  91                                 {
  92                                         /* Descriptor not found, error out */
  93                                         return NoCompatibleInterfaceFound;
  94                                 }
  95
  96                                 /* Clear any found endpoints */
  97                                 DataINEndpoint       = NULL;
  98                                 DataOUTEndpoint      = NULL;
  99                         }
 100                         else
 101                         {
 102                                 /* Get the next RNDIS control interface from the configuration descriptor */
 103                                 if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
 104                                                                                           DComp_NextCDCControlInterface) != DESCRIPTOR_SEARCH_COMP_Found)
 105                                 {
 106                                         /* Descriptor not found, error out */
 107                                         return NoCompatibleInterfaceFound;
 108                                 }
 109
 110                                 /* Clear any found endpoints */
 111                                 NotificationEndpoint = NULL;
 112                         }
 113
 114                         /* Skip the remainder of the loop as we have not found an endpoint yet */
 115                         continue;
 116                 }
 117
 118                 /* Retrieve the endpoint address from the endpoint descriptor */
 119                 USB_Descriptor_Endpoint_t* EndpointData = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Endpoint_t);
 120
 121                 /* If the endpoint is a IN type endpoint */
 122                 if (EndpointData->EndpointAddress & ENDPOINT_DESCRIPTOR_DIR_IN)
 123                 {
 124                         /* Check if the found endpoint is a interrupt or bulk type descriptor */
 125                         if ((EndpointData->Attributes & EP_TYPE_MASK) == EP_TYPE_INTERRUPT)
 126                           NotificationEndpoint = EndpointData;
 127                         else
 128                           DataINEndpoint = EndpointData;
 129                 }
 130                 else
 131                 {
 132                         DataOUTEndpoint = EndpointData;
 133                 }
 134         }
 135
 136         /* Configure the RNDIS data IN pipe */
 137         Pipe_ConfigurePipe(RNDIS_DATA_IN_PIPE, EP_TYPE_BULK, PIPE_TOKEN_IN,
 138                            DataINEndpoint->EndpointAddress, DataINEndpoint->EndpointSize, PIPE_BANK_SINGLE);
 139
 140         /* Configure the RNDIS data OUT pipe */
 141         Pipe_ConfigurePipe(RNDIS_DATA_OUT_PIPE, EP_TYPE_BULK, PIPE_TOKEN_OUT,
 142                                            DataOUTEndpoint->EndpointAddress, DataOUTEndpoint->EndpointSize, PIPE_BANK_SINGLE);
 143
 144         /* Configure the RNDIS notification pipe */
 145         Pipe_ConfigurePipe(RNDIS_NOTIFICATION_PIPE, EP_TYPE_INTERRUPT, PIPE_TOKEN_IN,
 146                                            NotificationEndpoint->EndpointAddress, NotificationEndpoint->EndpointSize, PIPE_BANK_SINGLE);
 147         Pipe_SetInterruptPeriod(NotificationEndpoint->PollingIntervalMS);
 148
 149         /* Valid data found, return success */
 150         return SuccessfulConfigRead;
 151 }
 152
 153 /** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's
 154  *  configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration
 155  *  descriptor processing if an incompatible descriptor configuration is found.
 156  *
 157  *  This comparator searches for the next Interface descriptor of the correct CDC control Class, Subclass and Protocol values.
 158  *
 159  *  \return A value from the DSEARCH_Return_ErrorCodes_t enum
 160  */
 161 uint8_t DComp_NextCDCControlInterface(void* CurrentDescriptor)
 162 {
 163         if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Interface)
 164         {
 165                 /* Check the CDC descriptor class, subclass and protocol, break out if correct control interface found */
 166                 if ((DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).Class    == CDC_CONTROL_CLASS)    &&
 167                     (DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).SubClass == CDC_CONTROL_SUBCLASS) &&
 168                     (DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).Protocol == CDC_CONTROL_PROTOCOL))
 169                 {
 170                         return DESCRIPTOR_SEARCH_Found;
 171                 }
 172         }
 173
 174         return DESCRIPTOR_SEARCH_NotFound;
 175 }
 176
 177 /** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's
 178  *  configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration
 179  *  descriptor processing if an incompatible descriptor configuration is found.
 180  *
 181  *  This comparator searches for the next Interface descriptor of the correct CDC data Class, Subclass and Protocol values.
 182  *
 183  *  \return A value from the DSEARCH_Return_ErrorCodes_t enum
 184  */
 185 uint8_t DComp_NextCDCDataInterface(void* CurrentDescriptor)
 186 {
 187         if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Interface)
 188         {
 189                 /* Check the CDC descriptor class, subclass and protocol, break out if correct data interface found */
 190                 if ((DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).Class    == CDC_DATA_CLASS)    &&
 191                     (DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).SubClass == CDC_DATA_SUBCLASS) &&
 192                     (DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).Protocol == CDC_DATA_PROTOCOL))
 193                 {
 194                         return DESCRIPTOR_SEARCH_Found;
 195                 }
 196         }
 197
 198         return DESCRIPTOR_SEARCH_NotFound;
 199 }
 200
 201 /** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's
 202  *  configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration
 203  *  descriptor processing if an incompatible descriptor configuration is found.
 204  *
 205  *  This comparator searches for the next bulk IN or OUT endpoint, or interrupt IN endpoint within the current interface,
 206  *  aborting the search if another interface descriptor is found before the required endpoint (so that it may be compared
 207  *  using a different comparator to determine if it is another CDC class interface).
 208  *
 209  *  \return A value from the DSEARCH_Return_ErrorCodes_t enum
 210  */
 211 uint8_t DComp_NextCDCDataInterfaceEndpoint(void* CurrentDescriptor)
 212 {
 213         if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Endpoint)
 214         {
 215                 uint8_t EndpointType = (DESCRIPTOR_CAST(CurrentDescriptor,
 216                                                         USB_Descriptor_Endpoint_t).Attributes & EP_TYPE_MASK);
 217
 218                 if ((EndpointType == EP_TYPE_BULK) || (EndpointType == EP_TYPE_INTERRUPT))
 219                   return DESCRIPTOR_SEARCH_Found;
 220         }
 221         else if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Interface)
 222         {
 223                 return DESCRIPTOR_SEARCH_Fail;
 224         }
 225
 226         return DESCRIPTOR_SEARCH_NotFound;
 227 }