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Diffstat (limited to 'Demos/Host/LowLevel/VirtualSerialHost/ConfigDescriptor.c')
| -rw-r--r-- | Demos/Host/LowLevel/VirtualSerialHost/ConfigDescriptor.c | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/Demos/Host/LowLevel/VirtualSerialHost/ConfigDescriptor.c b/Demos/Host/LowLevel/VirtualSerialHost/ConfigDescriptor.c new file mode 100644 index 0000000000..fa5312ffe2 --- /dev/null +++ b/Demos/Host/LowLevel/VirtualSerialHost/ConfigDescriptor.c @@ -0,0 +1,234 @@ +/* + 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 CDC interface descriptor containing bulk data IN and OUT endpoints, and an interrupt event endpoint. + * + * \return An error code from the \ref CDCHost_GetConfigDescriptorDataCodes_t enum. + */ +uint8_t ProcessConfigurationDescriptor(void) +{ + uint8_t ConfigDescriptorData[512]; + void* CurrConfigLocation = ConfigDescriptorData; + uint16_t CurrConfigBytesRem; + + USB_Descriptor_Interface_t* CDCControlInterface = NULL; + USB_Descriptor_Endpoint_t* DataINEndpoint = NULL; + USB_Descriptor_Endpoint_t* DataOUTEndpoint = NULL; + USB_Descriptor_Endpoint_t* NotificationEndpoint = 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) || !(NotificationEndpoint)) + { + /* See if we've found a likely compatible interface, and if there is an endpoint within that interface */ + if (!(CDCControlInterface) || + USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation, + DComp_NextCDCDataInterfaceEndpoint) != DESCRIPTOR_SEARCH_COMP_Found) + { + /* Check if we have already found the control interface's notification endpoint or not */ + if (NotificationEndpoint) + { + /* Get the next CDC data interface from the configuration descriptor */ + if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation, + DComp_NextCDCDataInterface) != DESCRIPTOR_SEARCH_COMP_Found) + { + /* Descriptor not found, error out */ + return NoCompatibleInterfaceFound; + } + + /* Clear any found endpoints */ + DataINEndpoint = NULL; + DataOUTEndpoint = NULL; + } + else + { + /* Get the next CDC control interface from the configuration descriptor */ + if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation, + DComp_NextCDCControlInterface) != DESCRIPTOR_SEARCH_COMP_Found) + { + /* Descriptor not found, error out */ + return NoCompatibleInterfaceFound; + } + + /* Save the interface in case we need to refer back to it later */ + CDCControlInterface = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t); + + /* Clear any found endpoints */ + NotificationEndpoint = 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) + { + /* Check if the found endpoint is a interrupt or bulk type descriptor */ + if ((EndpointData->Attributes & EP_TYPE_MASK) == EP_TYPE_INTERRUPT) + NotificationEndpoint = EndpointData; + else + DataINEndpoint = EndpointData; + } + else + { + DataOUTEndpoint = EndpointData; + } + } + + /* Configure the CDC data IN pipe */ + Pipe_ConfigurePipe(CDC_DATA_IN_PIPE, EP_TYPE_BULK, DataINEndpoint->EndpointAddress, DataINEndpoint->EndpointSize, 1); + + /* Configure the CDC data OUT pipe */ + Pipe_ConfigurePipe(CDC_DATA_OUT_PIPE, EP_TYPE_BULK, DataOUTEndpoint->EndpointAddress, DataOUTEndpoint->EndpointSize, 1); + + /* Configure the CDC notification pipe */ + Pipe_ConfigurePipe(CDC_NOTIFICATION_PIPE, EP_TYPE_INTERRUPT, NotificationEndpoint->EndpointAddress, NotificationEndpoint->EndpointSize, 1); + Pipe_SetInterruptPeriod(NotificationEndpoint->PollingIntervalMS); + + /* 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 CDC control Class, Subclass and Protocol values. + * + * \return A value from the DSEARCH_Return_ErrorCodes_t enum + */ +uint8_t DComp_NextCDCControlInterface(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 CDC descriptor class, subclass and protocol, break out if correct control interface found */ + if ((Interface->Class == CDC_CSCP_CDCClass) && + (Interface->SubClass == CDC_CSCP_ACMSubclass) && + (Interface->Protocol == CDC_CSCP_ATCommandProtocol)) + { + 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 Interface descriptor of the correct CDC data Class, Subclass and Protocol values. + * + * \return A value from the DSEARCH_Return_ErrorCodes_t enum + */ +uint8_t DComp_NextCDCDataInterface(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 CDC descriptor class, subclass and protocol, break out if correct data interface found */ + if ((Interface->Class == CDC_CSCP_CDCDataClass) && + (Interface->SubClass == CDC_CSCP_NoDataSubclass) && + (Interface->Protocol == CDC_CSCP_NoDataProtocol)) + { + 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, or interrupt IN endpoint within the current interface, + * aborting the search if another interface descriptor is found before the required endpoint (so that it may be compared + * using a different comparator to determine if it is another CDC class interface). + * + * \return A value from the DSEARCH_Return_ErrorCodes_t enum + */ +uint8_t DComp_NextCDCDataInterfaceEndpoint(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); + + if (((Endpoint->Attributes & EP_TYPE_MASK) == EP_TYPE_BULK) || + ((Endpoint->Attributes & EP_TYPE_MASK) == EP_TYPE_INTERRUPT)) + { + return DESCRIPTOR_SEARCH_Found; + } + } + else if (Header->Type == DTYPE_Interface) + { + return DESCRIPTOR_SEARCH_Fail; + } + + return DESCRIPTOR_SEARCH_NotFound; +} + |