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Diffstat (limited to 'lib/lufa/Demos/Host/LowLevel/AndroidAccessoryHost/ConfigDescriptor.c')
| -rw-r--r-- | lib/lufa/Demos/Host/LowLevel/AndroidAccessoryHost/ConfigDescriptor.c | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/lib/lufa/Demos/Host/LowLevel/AndroidAccessoryHost/ConfigDescriptor.c b/lib/lufa/Demos/Host/LowLevel/AndroidAccessoryHost/ConfigDescriptor.c new file mode 100644 index 000000000..d4aa87762 --- /dev/null +++ b/lib/lufa/Demos/Host/LowLevel/AndroidAccessoryHost/ConfigDescriptor.c @@ -0,0 +1,164 @@ +/* + 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 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; + } + + /* 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; + } + + while (!(DataINEndpoint) || !(DataOUTEndpoint)) + { + /* Get the next Android Accessory Mode interface's data endpoint descriptor */ + 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 */ + if ((EndpointData->EndpointAddress & ENDPOINT_DIR_MASK) == ENDPOINT_DIR_IN) + DataINEndpoint = EndpointData; + else + DataOUTEndpoint = EndpointData; + } + + /* Configure the Android Accessory data IN pipe */ + Pipe_ConfigurePipe(ANDROID_DATA_IN_PIPE, EP_TYPE_BULK, DataINEndpoint->EndpointAddress, DataINEndpoint->EndpointSize, 1); + + /* Configure the Android Accessory data OUT pipe */ + Pipe_ConfigurePipe(ANDROID_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 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 == AOA_CSCP_AOADataClass) && + (Interface->SubClass == AOA_CSCP_AOADataSubclass) && + (Interface->Protocol == AOA_CSCP_AOADataProtocol)) + { + 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 + * 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); + + 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; +} + |