ConfigDescriptor.c 6.8 KB
 Dean Camera committed Jun 05, 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 HID interface descriptor containing at least one Interrupt type IN endpoint. *  Dean Camera committed Nov 04, 2009 46  * \return An error code from the \ref GenericHIDHost_GetConfigDescriptorDataCodes_t enum.  Dean Camera committed Jun 05, 2009 47 48 49  */ uint8_t ProcessConfigurationDescriptor(void) {  Dean Camera committed Aug 31, 2009 50  uint8_t ConfigDescriptorData[512];  Dean Camera committed Nov 07, 2009 51  void* CurrConfigLocation = ConfigDescriptorData;  Dean Camera committed Aug 31, 2009 52  uint16_t CurrConfigBytesRem;  Dean Camera committed Jun 05, 2009 53 54 55  uint8_t FoundEndpoints = 0; /* Retrieve the entire configuration descriptor into the allocated buffer */  Dean Camera committed Aug 31, 2009 56 57 58 59 60 61 62 63 64 65 66  switch (USB_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; }  Dean Camera committed Jun 05, 2009 67 68  /* Get the HID interface from the configuration descriptor */  Dean Camera committed Aug 31, 2009 69  if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,  Dean Camera committed Jun 05, 2009 70 71 72 73 74 75 76 77 78  DComp_NextHIDInterface) != DESCRIPTOR_SEARCH_COMP_Found) { /* Descriptor not found, error out */ return NoHIDInterfaceFound; } while (FoundEndpoints != ((1 << HID_DATA_IN_PIPE) | (1 << HID_DATA_OUT_PIPE))) { /* Get the next HID interface's data endpoint descriptor */  Dean Camera committed Aug 31, 2009 79  if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,  Dean Camera committed Oct 08, 2009 80  DComp_NextHIDInterfaceDataEndpoint) != DESCRIPTOR_SEARCH_COMP_Found)  Dean Camera committed Jun 05, 2009 81 82 83 84 85 86 87 88 89 90 91  { /* 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 (FoundEndpoints == (1 << HID_DATA_IN_PIPE)) break; /* Descriptor not found, error out */ return NoEndpointFound; } /* Retrieve the endpoint address from the endpoint descriptor */  Dean Camera committed Aug 31, 2009 92  USB_Descriptor_Endpoint_t* EndpointData = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Endpoint_t);  Dean Camera committed Jun 05, 2009 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122  /* If the endpoint is a IN type endpoint */ if (EndpointData->EndpointAddress & ENDPOINT_DESCRIPTOR_DIR_IN) { /* Configure the HID data IN pipe */ Pipe_ConfigurePipe(HID_DATA_IN_PIPE, EP_TYPE_INTERRUPT, PIPE_TOKEN_IN, EndpointData->EndpointAddress, EndpointData->EndpointSize, PIPE_BANK_SINGLE); FoundEndpoints |= (1 << HID_DATA_IN_PIPE); } else { /* Configure the HID data OUT pipe */ Pipe_ConfigurePipe(HID_DATA_OUT_PIPE, EP_TYPE_INTERRUPT, PIPE_TOKEN_OUT, EndpointData->EndpointAddress, EndpointData->EndpointSize, PIPE_BANK_SINGLE); FoundEndpoints |= (1 << HID_DATA_OUT_PIPE); } } /* 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. *  Dean Camera committed Nov 04, 2009 123  * \return A value from the DSEARCH_Return_ErrorCodes_t enum  Dean Camera committed Jun 05, 2009 124 125 126 127 128 129  */ uint8_t DComp_NextHIDInterface(void* CurrentDescriptor) { /* Determine if the current descriptor is an interface descriptor */ if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Interface) {  Dean Camera committed Jun 20, 2009 130  /* Check the HID descriptor class, break out if correct class/protocol interface found */  Dean Camera committed Jun 05, 2009 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148  if (DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).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. *  Dean Camera committed Nov 04, 2009 149  * \return A value from the DSEARCH_Return_ErrorCodes_t enum  Dean Camera committed Jun 05, 2009 150  */  Dean Camera committed Oct 08, 2009 151 uint8_t DComp_NextHIDInterfaceDataEndpoint(void* CurrentDescriptor)  Dean Camera committed Jun 05, 2009 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 { /* Determine the type of the current descriptor */ if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Endpoint) { /* Indicate that the descriptor being searched for has been found */ return DESCRIPTOR_SEARCH_Found; } else if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Interface) { /* Indicate that the search has failed prematurely and should be aborted */ return DESCRIPTOR_SEARCH_Fail; } /* Current descriptor does not match what this comparator is looking for */ return DESCRIPTOR_SEARCH_NotFound; }