Demos/Host/Incomplete/BluetoothHost/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 BT interface descriptor containing bulk IN and OUT data endpoints.
  45  *
  46  *  \return An error code from the \ref BluetoothHost_GetConfigDescriptorDataCodes_t enum.
  47  */
  48 uint8_t ProcessConfigurationDescriptor(void)
  49 {
  50         uint8_t  ConfigDescriptorData[512];
  51         void*    CurrConfigLocation = ConfigDescriptorData;
  52         uint16_t CurrConfigBytesRem;
  53         uint8_t  FoundEndpoints = 0;
  54
  55         /* Retrieve the entire configuration descriptor into the allocated buffer */
  56         switch (USB_Host_GetDeviceConfigDescriptor(1, &CurrConfigBytesRem, ConfigDescriptorData, sizeof(ConfigDescriptorData)))
  57         {
  58                 case HOST_GETCONFIG_Successful:
  59                         break;
  60                 case HOST_GETCONFIG_InvalidData:
  61                         return InvalidConfigDataReturned;
  62                 case HOST_GETCONFIG_BuffOverflow:
  63                         return DescriptorTooLarge;
  64                 default:
  65                         return ControlError;
  66         }
  67
  68         /* The bluetooth USB transport addendum mandates that the data (not streaming voice) endpoints
  69            be in the first interface descriptor (interface 0) */
  70         USB_GetNextDescriptorOfType(&CurrConfigBytesRem, &CurrConfigLocation, DTYPE_Interface);
  71
  72         /* Ensure that an interface was found, and the end of the descriptor was not reached */
  73         if (!(CurrConfigBytesRem))
  74           return NoBTInterfaceFound;
  75
  76         /* Get the data IN, data OUT and event notification endpoints for the bluetooth interface */
  77         while (FoundEndpoints != ((1 << BLUETOOTH_DATA_IN_PIPE) | (1 << BLUETOOTH_DATA_OUT_PIPE) |
  78                                   (1 << BLUETOOTH_EVENTS_PIPE)))
  79         {
  80                 /* Fetch the next endpoint from the current bluetooth interface */
  81                 if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
  82                                               DComp_NextInterfaceBluetoothDataEndpoint))
  83                 {
  84                         /* Descriptor not found, error out */
  85                         return NoEndpointFound;
  86                 }
  87
  88                 USB_Descriptor_Endpoint_t* EndpointData = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Endpoint_t);
  89
  90                 /* Check if the endpoint is a bulk or interrupt type endpoint */
  91                 if ((EndpointData->Attributes & EP_TYPE_MASK) == EP_TYPE_INTERRUPT)
  92                 {
  93                         if (EndpointData->EndpointAddress & ENDPOINT_DESCRIPTOR_DIR_IN)
  94                         {
  95                                 /* Configure the events IN pipe */
  96                                 Pipe_ConfigurePipe(BLUETOOTH_EVENTS_PIPE, EP_TYPE_INTERRUPT, PIPE_TOKEN_IN,
  97                                                                    EndpointData->EndpointAddress, EndpointData->EndpointSize,
  98                                                                    PIPE_BANK_SINGLE);
  99
 100                                 Pipe_SetInterruptPeriod(EndpointData->PollingIntervalMS);
 101
 102                                 /* Set the flag indicating that the events notification pipe has been found */
 103                                 FoundEndpoints |= (1 << BLUETOOTH_EVENTS_PIPE);
 104                         }
 105                 }
 106                 else
 107                 {
 108                         if (EndpointData->EndpointAddress & ENDPOINT_DESCRIPTOR_DIR_IN)
 109                         {
 110                                 /* Configure the data IN pipe */
 111                                 Pipe_ConfigurePipe(BLUETOOTH_DATA_IN_PIPE, EP_TYPE_BULK, PIPE_TOKEN_IN,
 112                                                                    EndpointData->EndpointAddress, EndpointData->EndpointSize,
 113                                                                    PIPE_BANK_SINGLE);
 114
 115                                 /* Set the flag indicating that the data IN pipe has been found */
 116                                 FoundEndpoints |= (1 << BLUETOOTH_DATA_IN_PIPE);
 117                         }
 118                         else
 119                         {
 120                                 /* Configure the data OUT pipe */
 121                                 Pipe_ConfigurePipe(BLUETOOTH_DATA_OUT_PIPE, EP_TYPE_BULK, PIPE_TOKEN_OUT,
 122                                                                    EndpointData->EndpointAddress, EndpointData->EndpointSize,
 123                                                                    PIPE_BANK_SINGLE);
 124
 125                                 /* Set the flag indicating that the data OUT pipe has been found */
 126                                 FoundEndpoints |= (1 << BLUETOOTH_DATA_OUT_PIPE);
 127                         }
 128                 }
 129
 130         }
 131
 132         /* Valid data found, return success */
 133         return SuccessfulConfigRead;
 134 }
 135
 136 /** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's
 137  *  configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration
 138  *  descriptor processing if an incompatible descriptor configuration is found.
 139  *
 140  *  This comparator searches for the next Endpoint descriptor inside the current interface descriptor, aborting the
 141  *  search if another interface descriptor is found before the required endpoint.
 142  *
 143  *  \return A value from the DSEARCH_Return_ErrorCodes_t enum
 144  */
 145 uint8_t DComp_NextInterfaceBluetoothDataEndpoint(void* CurrentDescriptor)
 146 {
 147         /* Determine the type of the current descriptor */
 148         if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Endpoint)
 149         {
 150                 /* Indicate that the descriptor being searched for has been found */
 151                 return DESCRIPTOR_SEARCH_Found;
 152         }
 153         else if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Interface)
 154         {
 155                 /* Indicate that the search has failed prematurely and should be aborted */
 156                 return DESCRIPTOR_SEARCH_Fail;
 157         }
 158
 159         /* Current descriptor does not match what this comparator is looking for */
 160         return DESCRIPTOR_SEARCH_NotFound;
 161 }
 162