diff options
Diffstat (limited to 'lib/lufa/Demos/Host/LowLevel/MIDIHost/ConfigDescriptor.c')
| -rw-r--r-- | lib/lufa/Demos/Host/LowLevel/MIDIHost/ConfigDescriptor.c | 173 |
1 files changed, 173 insertions, 0 deletions
diff --git a/lib/lufa/Demos/Host/LowLevel/MIDIHost/ConfigDescriptor.c b/lib/lufa/Demos/Host/LowLevel/MIDIHost/ConfigDescriptor.c new file mode 100644 index 0000000000..c02ec555c1 --- /dev/null +++ b/lib/lufa/Demos/Host/LowLevel/MIDIHost/ConfigDescriptor.c @@ -0,0 +1,173 @@ +/* + LUFA Library + Copyright (C) Dean Camera, 2017. + + dean [at] fourwalledcubicle [dot] com + www.lufa-lib.org +*/ + +/* + Copyright 2017 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 disclaims 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. + * + * \return An error code from the \ref MIDIHost_GetConfigDescriptorDataCodes_t enum. + */ +uint8_t ProcessConfigurationDescriptor(void) +{ + uint8_t ConfigDescriptorData[512]; + void* CurrConfigLocation = ConfigDescriptorData; + uint16_t CurrConfigBytesRem; + + USB_Descriptor_Interface_t* MIDIInterface = NULL; + 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 ControlError; + } + + while (!(DataINEndpoint) || !(DataOUTEndpoint)) + { + /* See if we've found a likely compatible interface, and if there is an endpoint within that interface */ + if (!(MIDIInterface) || + USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation, + DComp_NextMIDIStreamingDataEndpoint) != DESCRIPTOR_SEARCH_COMP_Found) + { + /* Get the next Mass Storage interface from the configuration descriptor */ + if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation, + DComp_NextMIDIStreamingInterface) != DESCRIPTOR_SEARCH_COMP_Found) + { + /* Descriptor not found, error out */ + return NoCompatibleInterfaceFound; + } + + /* Save the interface in case we need to refer back to it later */ + MIDIInterface = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t); + + /* Clear any found endpoints */ + DataINEndpoint = NULL; + DataOUTEndpoint = NULL; + + /* Skip the remainder of the loop as we have not found an endpoint yet */ + continue; + } + + /* 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 */ + if ((EndpointData->EndpointAddress & ENDPOINT_DIR_MASK) == ENDPOINT_DIR_IN) + DataINEndpoint = EndpointData; + else + DataOUTEndpoint = EndpointData; + } + + /* Configure the MIDI data IN pipe */ + Pipe_ConfigurePipe(MIDI_DATA_IN_PIPE, EP_TYPE_BULK, DataINEndpoint->EndpointAddress, DataINEndpoint->EndpointSize, 1); + + /* Configure the MIDI data OUT pipe */ + Pipe_ConfigurePipe(MIDI_DATA_OUT_PIPE, EP_TYPE_BULK, DataOUTEndpoint->EndpointAddress, DataOUTEndpoint->EndpointSize, 1); + + /* 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. + * + * \return A value from the DSEARCH_Return_ErrorCodes_t enum + */ +uint8_t DComp_NextMIDIStreamingInterface(void* 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); + + /* Check the MIDI descriptor class, subclass and protocol, break out if correct data interface found */ + if ((Interface->Class == AUDIO_CSCP_AudioClass) && + (Interface->SubClass == AUDIO_CSCP_MIDIStreamingSubclass) && + (Interface->Protocol == AUDIO_CSCP_StreamingProtocol)) + { + 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. + * + * \return A value from the DSEARCH_Return_ErrorCodes_t enum + */ +uint8_t DComp_NextMIDIStreamingDataEndpoint(void* 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); + + /* Check the endpoint type, break out if correct BULK type endpoint found */ + if ((Endpoint->Attributes & EP_TYPE_MASK) == EP_TYPE_BULK) + return DESCRIPTOR_SEARCH_Found; + } + else if (Header->Type == DTYPE_Interface) + { + return DESCRIPTOR_SEARCH_Fail; + } + + return DESCRIPTOR_SEARCH_NotFound; +} + |