Demos/Host/LowLevel/PrinterHost/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 #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         uint8_t* CurrConfigLocation = ConfigDescriptorData;
  51         uint16_t CurrConfigBytesRem;
  52         uint8_t  FoundEndpoints = 0;
  53
  54         /* Retrieve the entire configuration descriptor into the allocated buffer */
  55         switch (USB_GetDeviceConfigDescriptor(1, &CurrConfigBytesRem, ConfigDescriptorData, sizeof(ConfigDescriptorData)))
  56         {
  57                 case HOST_GETCONFIG_Successful:
  58                         break;
  59                 case HOST_GETCONFIG_InvalidData:
  60                         return InvalidConfigDataReturned;
  61                 case HOST_GETCONFIG_BuffOverflow:
  62                         return DescriptorTooLarge;
  63                 default:
  64                         return ControlError;
  65         }
  66
  67         /* Get the printer interface from the configuration descriptor */
  68         if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation, DComp_NextBidirectionalPrinterInterface))
  69         {
  70                 /* Descriptor not found, error out */
  71                 return NoInterfaceFound;
  72         }
  73
  74         PrinterInterfaceNumber = DESCRIPTOR_CAST(CurrConfigLocation, USB_Descriptor_Interface_t).InterfaceNumber;
  75         PrinterAltSetting      = DESCRIPTOR_CAST(CurrConfigLocation, USB_Descriptor_Interface_t).AlternateSetting;
  76
  77         /* Get the IN and OUT data endpoints for the printer interface */
  78         while (FoundEndpoints != ((1 << PRINTER_DATA_OUT_PIPE) | (1 << PRINTER_DATA_IN_PIPE)))
  79         {
  80                 /* Fetch the next bulk endpoint from the current printer interface */
  81                 if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation, DComp_NextPrinterInterfaceBulkDataEndpoint))
  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 endpoint is a bulk IN or bulk OUT endpoint, set appropriate globals */
  90                 if (EndpointData->EndpointAddress & ENDPOINT_DESCRIPTOR_DIR_IN)
  91                 {
  92                         /* Configure the data IN pipe */
  93                         Pipe_ConfigurePipe(PRINTER_DATA_IN_PIPE, EP_TYPE_BULK, PIPE_TOKEN_IN,
  94                                            EndpointData->EndpointAddress, EndpointData->EndpointSize,
  95                                            PIPE_BANK_SINGLE);
  96
  97                         Pipe_SetInfiniteINRequests();
  98
  99                         /* Set the flag indicating that the data IN pipe has been found */
 100                         FoundEndpoints |= (1 << PRINTER_DATA_IN_PIPE);
 101                 }
 102                 else
 103                 {
 104                         /* Configure the data OUT pipe */
 105                         Pipe_ConfigurePipe(PRINTER_DATA_OUT_PIPE, EP_TYPE_BULK, PIPE_TOKEN_OUT,
 106                                            EndpointData->EndpointAddress, EndpointData->EndpointSize,
 107                                            PIPE_BANK_SINGLE);
 108
 109                         /* Set the flag indicating that the data OUT pipe has been found */
 110                         FoundEndpoints |= (1 << PRINTER_DATA_OUT_PIPE);
 111                 }
 112         }
 113
 114         /* Valid data found, return success */
 115         return SuccessfulConfigRead;
 116 }
 117
 118 /** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's
 119  *  configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration
 120  *  descriptor processing if an incompatible descriptor configuration is found.
 121  *
 122  *  This comparator searches for the next Bidirectional Printer Interface descriptor of the current Printer interface,
 123  *  aborting the search if the end of the descriptors is found.
 124  *
 125  *  \return A value from the \ref DSEARCH_Return_ErrorCodes_t enum
 126  */
 127 uint8_t DComp_NextBidirectionalPrinterInterface(void* CurrentDescriptor)
 128 {
 129         if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Interface)
 130         {
 131                 /* Check the descriptor class and protocol, break out if correct class/protocol interface found */
 132                 if ((DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).Class    == PRINTER_CLASS)    &&
 133                     (DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).SubClass == PRINTER_SUBCLASS) &&
 134                         (DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).Protocol == PRINTER_PROTOCOL))
 135                 {
 136                         return DESCRIPTOR_SEARCH_Found;
 137                 }
 138         }
 139
 140         return DESCRIPTOR_SEARCH_NotFound;
 141 }
 142
 143 /** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's
 144  *  configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration
 145  *  descriptor processing if an incompatible descriptor configuration is found.
 146  *
 147  *  This comparator searches for the next Bulk Endpoint descriptor of the current Printer interface, aborting the
 148  *  search if another interface descriptor is found before the next endpoint.
 149  *
 150  *  \return A value from the \ref DSEARCH_Return_ErrorCodes_t enum
 151  */
 152 uint8_t DComp_NextPrinterInterfaceBulkDataEndpoint(void* CurrentDescriptor)
 153 {
 154         if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Endpoint)
 155         {
 156                 uint8_t EndpointType = (DESCRIPTOR_CAST(CurrentDescriptor,
 157                                                         USB_Descriptor_Endpoint_t).Attributes & EP_TYPE_MASK);
 158
 159                 /* Check the endpoint type, break out if correct BULK type endpoint found */
 160                 if (EndpointType == EP_TYPE_BULK)
 161                   return DESCRIPTOR_SEARCH_Found;
 162         }
 163         else if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Interface)
 164         {
 165                 return DESCRIPTOR_SEARCH_Fail;
 166         }
 167
 168         return DESCRIPTOR_SEARCH_NotFound;
 169 }