ConfigDescriptor.c 6.58 KB
 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 /* LUFA Library Copyright (C) Dean Camera, 2011. dean [at] fourwalledcubicle [dot] com www.lufa-lib.org */ /* Copyright 2011 Dean Camera (dean [at] fourwalledcubicle [dot] com) Permission to use, copy, modify, distribute, and sell this software and its documentation for any purpose is hereby granted without fee, provided that the above copyright notice appear in all copies and that both that the copyright notice and this permission notice and warranty disclaimer appear in supporting documentation, and that the name of the author not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission. The author disclaim all warranties with regard to this software, including all implied warranties of merchantability and fitness. In no event shall the author be liable for any special, indirect or consequential damages or any damages whatsoever resulting from loss of use, data or profits, whether in an action of contract, negligence or other tortious action, arising out of or in connection with the use or performance of this software. */ /** \file * * USB Device Configuration Descriptor processing routines, to determine the correct pipe configurations * needed to communication with an attached USB device. Descriptors are special computer-readable structures * which the host requests upon device enumeration, to determine the device's capabilities and functions. */ #include "ConfigDescriptor.h" /** Reads and processes an attached device's descriptors, to determine compatibility and pipe configurations. This * routine will read in the entire configuration descriptor, and configure the hosts pipes to correctly communicate * with compatible devices. * * This routine searches for the first interface containing bulk IN and OUT data endpoints. * * \return An error code from the \ref AndroidHost_GetConfigDescriptorDataCodes_t enum. */ uint8_t ProcessConfigurationDescriptor(void) { uint8_t ConfigDescriptorData[512]; void* CurrConfigLocation = ConfigDescriptorData; uint16_t CurrConfigBytesRem; USB_Descriptor_Endpoint_t* DataINEndpoint = NULL; USB_Descriptor_Endpoint_t* DataOUTEndpoint = NULL; /* Retrieve the entire configuration descriptor into the allocated buffer */ switch (USB_Host_GetDeviceConfigDescriptor(1, &CurrConfigBytesRem, ConfigDescriptorData, sizeof(ConfigDescriptorData))) { case HOST_GETCONFIG_Successful: break; case HOST_GETCONFIG_InvalidData: return InvalidConfigDataReturned; case HOST_GETCONFIG_BuffOverflow: return DescriptorTooLarge; default: return DevControlError; }  Dean Camera committed Jul 10, 2011 69 70 71 72 73 74 75  /* There should be only one compatible Android Accessory Mode interface in the device, attempt to find it */ if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation, DCOMP_NextAndroidAccessoryInterface) != DESCRIPTOR_SEARCH_COMP_Found) { return NoCompatibleInterfaceFound; }  76 77 78  while (!(DataINEndpoint) || !(DataOUTEndpoint)) {  Dean Camera committed Jul 10, 2011 79  /* Get the next Android Accessory Mode interface's data endpoint descriptor */  80 81 82 83 84 85 86 87 88 89 90  if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation, DCOMP_NextInterfaceBulkEndpoint) != DESCRIPTOR_SEARCH_COMP_Found) { /* Data endpoints not found within the first Android Accessory device interface, error out */ return NoCompatibleInterfaceFound; } /* Retrieve the endpoint address from the endpoint descriptor */ USB_Descriptor_Endpoint_t* EndpointData = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Endpoint_t); /* If the endpoint is a IN type endpoint */  Dean Camera committed Jul 19, 2011 91  if ((EndpointData->EndpointAddress & ENDPOINT_DIR_MASK) == ENDPOINT_DIR_IN)  92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112  DataINEndpoint = EndpointData; else DataOUTEndpoint = EndpointData; } /* Configure the Android Accessory data IN pipe */ Pipe_ConfigurePipe(ANDROID_DATA_IN_PIPE, EP_TYPE_BULK, PIPE_TOKEN_IN, DataINEndpoint->EndpointAddress, DataINEndpoint->EndpointSize, PIPE_BANK_SINGLE); /* Configure the Android Accessory data OUT pipe */ Pipe_ConfigurePipe(ANDROID_DATA_OUT_PIPE, EP_TYPE_BULK, PIPE_TOKEN_OUT, DataOUTEndpoint->EndpointAddress, DataOUTEndpoint->EndpointSize, PIPE_BANK_SINGLE); /* Valid data found, return success */ return SuccessfulConfigRead; } /** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's * configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration * descriptor processing if an incompatible descriptor configuration is found. *  Dean Camera committed Jul 10, 2011 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141  * This comparator searches for the next Interface descriptor containing the correct Android Accessory Mode Class, Subclass * and Protocol values. * * \return A value from the DSEARCH_Return_ErrorCodes_t enum */ uint8_t DCOMP_NextAndroidAccessoryInterface(void* const CurrentDescriptor) { USB_Descriptor_Header_t* Header = DESCRIPTOR_PCAST(CurrentDescriptor, USB_Descriptor_Header_t); if (Header->Type == DTYPE_Interface) { USB_Descriptor_Interface_t* Interface = DESCRIPTOR_PCAST(CurrentDescriptor, USB_Descriptor_Interface_t); if ((Interface->Class == ANDROID_INTERFACE_CLASS) && (Interface->SubClass == ANDROID_INTERFACE_SUBCLASS) && (Interface->Protocol == ANDROID_INTERFACE_PROTOCOL)) { return DESCRIPTOR_SEARCH_Found; } } return DESCRIPTOR_SEARCH_NotFound; } /** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's * configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration * descriptor processing if an incompatible descriptor configuration is found. * * This comparator searches for the next bulk Endpoint descriptor inside the current interface descriptor, aborting the  142 143 144 145 146 147 148 149 150 151 152 153 154  * search if another interface descriptor is found before the required endpoint. * * \return A value from the DSEARCH_Return_ErrorCodes_t enum */ uint8_t DCOMP_NextInterfaceBulkEndpoint(void* const CurrentDescriptor) { USB_Descriptor_Header_t* Header = DESCRIPTOR_PCAST(CurrentDescriptor, USB_Descriptor_Header_t); if (Header->Type == DTYPE_Endpoint) { USB_Descriptor_Endpoint_t* Endpoint = DESCRIPTOR_PCAST(CurrentDescriptor, USB_Descriptor_Endpoint_t); uint8_t EndpointType = (Endpoint->Attributes & EP_TYPE_MASK);  Dean Camera committed Jul 10, 2011 155   156 157 158 159 160 161 162 163 164 165 166  if ((EndpointType == EP_TYPE_BULK) && (!(Pipe_IsEndpointBound(Endpoint->EndpointAddress)))) return DESCRIPTOR_SEARCH_Found; } else if (Header->Type == DTYPE_Interface) { return DESCRIPTOR_SEARCH_Fail; } return DESCRIPTOR_SEARCH_NotFound; }