ConfigDescriptor.c 6.78 KB
 Dean Camera committed Oct 08, 2009 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 /* LUFA Library Copyright (C) Dean Camera, 2009. dean [at] fourwalledcubicle [dot] com www.fourwalledcubicle.com */ /* Copyright 2009 Dean Camera (dean [at] fourwalledcubicle [dot] com) Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, 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 a MIDI interface descriptor pair containing bulk data IN and OUT endpoints. *  Dean Camera committed Nov 04, 2009 46  * \return An error code from the \ref MIDIHost_GetConfigDescriptorDataCodes_t enum.  Dean Camera committed Oct 08, 2009 47 48 49 50  */ uint8_t ProcessConfigurationDescriptor(void) { uint8_t ConfigDescriptorData[512];  Dean Camera committed Nov 07, 2009 51  void* CurrConfigLocation = ConfigDescriptorData;  Dean Camera committed Oct 08, 2009 52 53 54 55  uint16_t CurrConfigBytesRem; uint8_t FoundEndpoints = 0; /* Retrieve the entire configuration descriptor into the allocated buffer */  Dean Camera committed Nov 13, 2009 56  switch (USB_Host_GetDeviceConfigDescriptor(1, &CurrConfigBytesRem, ConfigDescriptorData, sizeof(ConfigDescriptorData)))  Dean Camera committed Oct 08, 2009 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119  { case HOST_GETCONFIG_Successful: break; case HOST_GETCONFIG_InvalidData: return InvalidConfigDataReturned; case HOST_GETCONFIG_BuffOverflow: return DescriptorTooLarge; default: return ControlError; } /* Get the MIDI Audio Streaming interface from the configuration descriptor */ if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation, DComp_NextMIDIStreamingInterface) != DESCRIPTOR_SEARCH_COMP_Found) { /* Descriptor not found, error out */ return NoCDCInterfaceFound; } /* Get the IN and OUT data endpoints for the MIDI interface */ while (FoundEndpoints != ((1 << MIDI_DATAPIPE_IN) | (1 << MIDI_DATAPIPE_OUT))) { /* Fetch the next bulk endpoint from the current MIDI streaming interface */ if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation, DComp_NextMIDIStreamingDataEndpoint) != DESCRIPTOR_SEARCH_COMP_Found) { /* Descriptor not found, error out */ return NoEndpointFound; } USB_Descriptor_Endpoint_t* EndpointData = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Endpoint_t); /* Check if the endpoint is a bulk IN or bulk OUT endpoint */ if (EndpointData->EndpointAddress & ENDPOINT_DESCRIPTOR_DIR_IN) { /* Configure the data IN pipe */ Pipe_ConfigurePipe(MIDI_DATAPIPE_IN, EP_TYPE_BULK, PIPE_TOKEN_IN, EndpointData->EndpointAddress, EndpointData->EndpointSize, PIPE_BANK_SINGLE); /* Set the flag indicating that the data IN pipe has been found */ FoundEndpoints |= (1 << MIDI_DATAPIPE_IN); } else { /* Configure the data OUT pipe */ Pipe_ConfigurePipe(MIDI_DATAPIPE_OUT, EP_TYPE_BULK, PIPE_TOKEN_OUT, EndpointData->EndpointAddress, EndpointData->EndpointSize, PIPE_BANK_SINGLE); /* Set the flag indicating that the data OUT pipe has been found */ FoundEndpoints |= (1 << MIDI_DATAPIPE_OUT); } } /* 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. * * This comparator searches for the next Interface descriptor of the correct MIDI Streaming Class, Subclass and Protocol values. *  Dean Camera committed Nov 04, 2009 120  * \return A value from the DSEARCH_Return_ErrorCodes_t enum  Dean Camera committed Oct 08, 2009 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144  */ uint8_t DComp_NextMIDIStreamingInterface(void* CurrentDescriptor) { if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Interface) { /* Check the MIDI descriptor class, subclass and protocol, break out if correct data interface found */ if ((DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).Class == MIDI_STREAMING_CLASS) && (DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).SubClass == MIDI_STREAMING_SUBCLASS) && (DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).Protocol == MIDI_STREAMING_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 IN or OUT endpoint within the current interface, aborting the search if * another interface descriptor is found before the required endpoint. *  Dean Camera committed Nov 04, 2009 145  * \return A value from the DSEARCH_Return_ErrorCodes_t enum  Dean Camera committed Oct 08, 2009 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164  */ uint8_t DComp_NextMIDIStreamingDataEndpoint(void* CurrentDescriptor) { if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Endpoint) { uint8_t EndpointType = (DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Endpoint_t).Attributes & EP_TYPE_MASK); /* Check the endpoint type, break out if correct BULK type endpoint found */ if (EndpointType == EP_TYPE_BULK) return DESCRIPTOR_SEARCH_Found; } else if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Interface) { return DESCRIPTOR_SEARCH_Fail; } return DESCRIPTOR_SEARCH_NotFound; }