Demos/Host/LowLevel/PrinterHost/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 #include "ConfigDescriptor.h"
  32
  33 /** Interface number for the bidirectional Printer interface found within the device. */
  34 uint8_t PrinterInterfaceNumber;
  35
  36 /** Interface Alternate Setting number for the bidirectional Printer interface found within the device. */
  37 uint8_t PrinterAltSetting;
  38
  39 /** Reads and processes an attached device's descriptors, to determine compatibility and pipe configurations. This
  40  *  routine will read in the entire configuration descriptor, and configure the hosts pipes to correctly communicate
  41  *  with compatible devices.
  42  *
  43  *  This routine searches for a bidirectional Printer interface descriptor containing bulk IN and OUT data endpoints.
  44  *
  45  *  \return An error code from the \ref PrinterHost_GetConfigDescriptorDataCodes_t enum.
  46  */
  47 uint8_t ProcessConfigurationDescriptor(void)
  48 {
  49         uint8_t  ConfigDescriptorData[512];
  50         void*    CurrConfigLocation = ConfigDescriptorData;
  51         uint16_t CurrConfigBytesRem;
  52
  53         USB_Descriptor_Endpoint_t* DataINEndpoint  = NULL;
  54         USB_Descriptor_Endpoint_t* DataOUTEndpoint = NULL;
  55
  56         /* Retrieve the entire configuration descriptor into the allocated buffer */
  57         switch (USB_Host_GetDeviceConfigDescriptor(1, &CurrConfigBytesRem, ConfigDescriptorData, sizeof(ConfigDescriptorData)))
  58         {
  59                 case HOST_GETCONFIG_Successful:
  60                         break;
  61                 case HOST_GETCONFIG_InvalidData:
  62                         return InvalidConfigDataReturned;
  63                 case HOST_GETCONFIG_BuffOverflow:
  64                         return DescriptorTooLarge;
  65                 default:
  66                         return ControlError;
  67         }
  68
  69         /* Get the first Printer interface from the configuration descriptor */
  70         if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
  71                                       DComp_NextBidirectionalPrinterInterface) != DESCRIPTOR_SEARCH_COMP_Found)
  72         {
  73                 /* Descriptor not found, error out */
  74                 return NoCompatibleInterfaceFound;
  75         }
  76
  77         /* Save Printer interface details for later use */
  78         PrinterInterfaceNumber = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t)->InterfaceNumber;
  79         PrinterAltSetting      = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t)->AlternateSetting;
  80
  81         while (!(DataINEndpoint) || !(DataOUTEndpoint))
  82         {
  83                 /* Get the next Printer interface's data endpoint descriptor */
  84                 if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
  85                                               DComp_NextPrinterInterfaceBulkDataEndpoint) != DESCRIPTOR_SEARCH_COMP_Found)
  86                 {
  87                         /* Clear any found endpoints */
  88                         DataINEndpoint  = NULL;
  89                         DataOUTEndpoint = NULL;
  90
  91                         /* Get the next Printer interface from the configuration descriptor */
  92                         if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
  93                                                                                   DComp_NextBidirectionalPrinterInterface) != DESCRIPTOR_SEARCH_COMP_Found)
  94                         {
  95                                 /* Descriptor not found, error out */
  96                                 return NoCompatibleInterfaceFound;
  97                         }
  98
  99                         /* Save Printer interface details for later use */
 100                         PrinterInterfaceNumber = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t)->InterfaceNumber;
 101                         PrinterAltSetting      = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t)->AlternateSetting;
 102
 103                         /* Skip the remainder of the loop as we have not found an endpoint yet */
 104                         continue;
 105                 }
 106
 107                 /* Retrieve the endpoint address from the endpoint descriptor */
 108                 USB_Descriptor_Endpoint_t* EndpointData = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Endpoint_t);
 109
 110                 /* If the endpoint is a IN type endpoint */
 111                 if (EndpointData->EndpointAddress & ENDPOINT_DESCRIPTOR_DIR_IN)
 112                   DataINEndpoint  = EndpointData;
 113                 else
 114                   DataOUTEndpoint = EndpointData;
 115         }
 116
 117         /* Configure the Printer data IN pipe */
 118         Pipe_ConfigurePipe(PRINTER_DATA_IN_PIPE, EP_TYPE_BULK, PIPE_TOKEN_IN,
 119                            DataINEndpoint->EndpointAddress, DataINEndpoint->EndpointSize, PIPE_BANK_SINGLE);
 120
 121         /* Configure the Printer data OUT pipe */
 122         Pipe_ConfigurePipe(PRINTER_DATA_OUT_PIPE, EP_TYPE_BULK, PIPE_TOKEN_OUT,
 123                                            DataOUTEndpoint->EndpointAddress, DataOUTEndpoint->EndpointSize, PIPE_BANK_SINGLE);
 124
 125         /* Valid data found, return success */
 126         return SuccessfulConfigRead;
 127 }
 128
 129 /** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's
 130  *  configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration
 131  *  descriptor processing if an incompatible descriptor configuration is found.
 132  *
 133  *  This comparator searches for the next Bidirectional Printer Interface descriptor of the current Printer interface,
 134  *  aborting the search if the end of the descriptors is found.
 135  *
 136  *  \return A value from the DSEARCH_Return_ErrorCodes_t enum
 137  */
 138 uint8_t DComp_NextBidirectionalPrinterInterface(void* CurrentDescriptor)
 139 {
 140         if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Interface)
 141         {
 142                 /* Check the descriptor class and protocol, break out if correct class/protocol interface found */
 143                 if ((DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).Class    == PRINTER_CLASS)    &&
 144                     (DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).SubClass == PRINTER_SUBCLASS) &&
 145                         (DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).Protocol == PRINTER_PROTOCOL))
 146                 {
 147                         return DESCRIPTOR_SEARCH_Found;
 148                 }
 149         }
 150
 151         return DESCRIPTOR_SEARCH_NotFound;
 152 }
 153
 154 /** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's
 155  *  configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration
 156  *  descriptor processing if an incompatible descriptor configuration is found.
 157  *
 158  *  This comparator searches for the next Bulk Endpoint descriptor of the current Printer interface, aborting the
 159  *  search if another interface descriptor is found before the next endpoint.
 160  *
 161  *  \return A value from the DSEARCH_Return_ErrorCodes_t enum
 162  */
 163 uint8_t DComp_NextPrinterInterfaceBulkDataEndpoint(void* CurrentDescriptor)
 164 {
 165         if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Endpoint)
 166         {
 167                 uint8_t EndpointType = (DESCRIPTOR_CAST(CurrentDescriptor,
 168                                                         USB_Descriptor_Endpoint_t).Attributes & EP_TYPE_MASK);
 169
 170                 /* Check the endpoint type, break out if correct BULK type endpoint found */
 171                 if (EndpointType == EP_TYPE_BULK)
 172                   return DESCRIPTOR_SEARCH_Found;
 173         }
 174         else if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Interface)
 175         {
 176                 return DESCRIPTOR_SEARCH_Fail;
 177         }
 178
 179         return DESCRIPTOR_SEARCH_NotFound;
 180 }