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_CAST(CurrConfigLocation, USB_Descriptor_Interface_t).InterfaceNumber;
  79         PrinterAltSetting      = DESCRIPTOR_CAST(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_CAST(CurrConfigLocation, USB_Descriptor_Interface_t).InterfaceNumber;
 101                         PrinterAltSetting      = DESCRIPTOR_CAST(CurrConfigLocation, USB_Descriptor_Interface_t).AlternateSetting;
 102                 }
 103
 104                 /* Retrieve the endpoint address from the endpoint descriptor */
 105                 USB_Descriptor_Endpoint_t* EndpointData = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Endpoint_t);
 106
 107                 /* If the endpoint is a IN type endpoint */
 108                 if (EndpointData->EndpointAddress & ENDPOINT_DESCRIPTOR_DIR_IN)
 109                   DataINEndpoint = EndpointData;
 110                 else
 111                   DataOUTEndpoint = EndpointData;
 112         }
 113
 114         /* Configure the Printer data IN pipe */
 115         Pipe_ConfigurePipe(PRINTER_DATA_IN_PIPE, EP_TYPE_BULK, PIPE_TOKEN_IN,
 116                            DataINEndpoint->EndpointAddress, DataINEndpoint->EndpointSize, PIPE_BANK_SINGLE);
 117
 118         /* Configure the Printer data OUT pipe */
 119         Pipe_ConfigurePipe(PRINTER_DATA_OUT_PIPE, EP_TYPE_BULK, PIPE_TOKEN_OUT,
 120                                            DataOUTEndpoint->EndpointAddress, DataOUTEndpoint->EndpointSize, PIPE_BANK_SINGLE);
 121
 122         /* Valid data found, return success */
 123         return SuccessfulConfigRead;
 124 }
 125
 126 /** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's
 127  *  configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration
 128  *  descriptor processing if an incompatible descriptor configuration is found.
 129  *
 130  *  This comparator searches for the next Bidirectional Printer Interface descriptor of the current Printer interface,
 131  *  aborting the search if the end of the descriptors is found.
 132  *
 133  *  \return A value from the DSEARCH_Return_ErrorCodes_t enum
 134  */
 135 uint8_t DComp_NextBidirectionalPrinterInterface(void* CurrentDescriptor)
 136 {
 137         if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Interface)
 138         {
 139                 /* Check the descriptor class and protocol, break out if correct class/protocol interface found */
 140                 if ((DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).Class    == PRINTER_CLASS)    &&
 141                     (DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).SubClass == PRINTER_SUBCLASS) &&
 142                         (DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).Protocol == PRINTER_PROTOCOL))
 143                 {
 144                         return DESCRIPTOR_SEARCH_Found;
 145                 }
 146         }
 147
 148         return DESCRIPTOR_SEARCH_NotFound;
 149 }
 150
 151 /** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's
 152  *  configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration
 153  *  descriptor processing if an incompatible descriptor configuration is found.
 154  *
 155  *  This comparator searches for the next Bulk Endpoint descriptor of the current Printer interface, aborting the
 156  *  search if another interface descriptor is found before the next endpoint.
 157  *
 158  *  \return A value from the DSEARCH_Return_ErrorCodes_t enum
 159  */
 160 uint8_t DComp_NextPrinterInterfaceBulkDataEndpoint(void* CurrentDescriptor)
 161 {
 162         if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Endpoint)
 163         {
 164                 uint8_t EndpointType = (DESCRIPTOR_CAST(CurrentDescriptor,
 165                                                         USB_Descriptor_Endpoint_t).Attributes & EP_TYPE_MASK);
 166
 167                 /* Check the endpoint type, break out if correct BULK type endpoint found */
 168                 if (EndpointType == EP_TYPE_BULK)
 169                   return DESCRIPTOR_SEARCH_Found;
 170         }
 171         else if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Interface)
 172         {
 173                 return DESCRIPTOR_SEARCH_Fail;
 174         }
 175
 176         return DESCRIPTOR_SEARCH_NotFound;
 177 }