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Diffstat (limited to 'Projects/MissileLauncher/ConfigDescriptor.c')
-rw-r--r-- | Projects/MissileLauncher/ConfigDescriptor.c | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/Projects/MissileLauncher/ConfigDescriptor.c b/Projects/MissileLauncher/ConfigDescriptor.c new file mode 100644 index 000000000..d6a7b8726 --- /dev/null +++ b/Projects/MissileLauncher/ConfigDescriptor.c @@ -0,0 +1,185 @@ +/* + 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 HID interface descriptor containing at least one Interrupt type IN endpoint. + * + * \return An error code from the GenericHIDHost_GetConfigDescriptorDataCodes_t enum. + */ +uint8_t ProcessConfigurationDescriptor(void) +{ + uint8_t ConfigDescriptorData[512]; + void* CurrConfigLocation = ConfigDescriptorData; + uint16_t CurrConfigBytesRem; + + USB_Descriptor_Interface_t* HIDInterface = 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 (!(HIDInterface) || + USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation, + DComp_NextHIDInterfaceDataEndpoint) != DESCRIPTOR_SEARCH_COMP_Found) + { + /* Not all HID devices have an OUT endpoint - if we've reached the end of the HID descriptor + * but only found the mandatory IN endpoint, it's safe to continue with the device enumeration */ + if (DataINEndpoint) + break; + + /* Get the next HID interface from the configuration descriptor */ + if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation, + DComp_NextHIDInterface) != DESCRIPTOR_SEARCH_COMP_Found) + { + /* Descriptor not found, error out */ + return NoCompatibleInterfaceFound; + } + + /* Save the interface in case we need to refer back to it later */ + HIDInterface = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t); + + /* Clear any found endpoints */ + 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 HID data IN pipe */ + Pipe_ConfigurePipe(HID_DATA_IN_PIPE, EP_TYPE_INTERRUPT, DataINEndpoint->EndpointAddress, DataINEndpoint->EndpointSize, 1); + Pipe_SetInterruptPeriod(DataINEndpoint->PollingIntervalMS); + + /* Check if the HID interface contained an optional OUT data endpoint */ + if (DataOUTEndpoint) + { + /* Configure the HID data OUT pipe */ + Pipe_ConfigurePipe(HID_DATA_OUT_PIPE, EP_TYPE_INTERRUPT, 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 HID Class value. + * + * \return A value from the DSEARCH_Return_ErrorCodes_t enum + */ +uint8_t DComp_NextHIDInterface(void* CurrentDescriptor) +{ + USB_Descriptor_Header_t* Header = DESCRIPTOR_PCAST(CurrentDescriptor, USB_Descriptor_Header_t); + + /* Determine if the current descriptor is an interface descriptor */ + if (Header->Type == DTYPE_Interface) + { + USB_Descriptor_Interface_t* Interface = DESCRIPTOR_PCAST(CurrentDescriptor, USB_Descriptor_Interface_t); + + /* Check the HID descriptor class and protocol, break out if correct class/protocol interface found */ + if (Interface->Class == HID_CLASS) + { + /* Indicate that the descriptor being searched for has been found */ + return DESCRIPTOR_SEARCH_Found; + } + } + + /* Current descriptor does not match what this comparator is looking for */ + 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 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_NextHIDInterfaceDataEndpoint(void* CurrentDescriptor) +{ + USB_Descriptor_Header_t* Header = DESCRIPTOR_PCAST(CurrentDescriptor, USB_Descriptor_Header_t); + + /* Determine the type of the current descriptor */ + if (Header->Type == DTYPE_Endpoint) + { + /* Indicate that the descriptor being searched for has been found */ + return DESCRIPTOR_SEARCH_Found; + } + else if (Header->Type == DTYPE_Interface) + { + /* Indicate that the search has failed prematurely and should be aborted */ + return DESCRIPTOR_SEARCH_Fail; + } + else + { + /* Current descriptor does not match what this comparator is looking for */ + return DESCRIPTOR_SEARCH_NotFound; + } +} + |