Demos/Host/LowLevel/MouseHostWithParser/ConfigDescriptor.c

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2010.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6       www.fourwalledcubicle.com
   7 */
   8
   9 /*
  10   Copyright 2010  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Permission to use, copy, modify, distribute, and sell this
  13   software and its documentation for any purpose is hereby granted
  14   without fee, provided that the above copyright notice appear in
  15   all copies and that both that the copyright notice and this
  16   permission notice and warranty disclaimer appear in supporting
  17   documentation, and that the name of the author not be used in
  18   advertising or publicity pertaining to distribution of the
  19   software without specific, written prior permission.
  20
  21   The author disclaim all warranties with regard to this
  22   software, including all implied warranties of merchantability
  23   and fitness.  In no event shall the author be liable for any
  24   special, indirect or consequential damages or any damages
  25   whatsoever resulting from loss of use, data or profits, whether
  26   in an action of contract, negligence or other tortious action,
  27   arising out of or in connection with the use or performance of
  28   this software.
  29 */
  30
  31 /** \file
  32  *
  33  *  USB Device Configuration Descriptor processing routines, to determine the correct pipe configurations
  34  *  needed to communication with an attached USB device. Descriptors are special  computer-readable structures
  35  *  which the host requests upon device enumeration, to determine the device's capabilities and functions.
  36  */
  37
  38 #include "ConfigDescriptor.h"
  39
  40 /** Reads and processes an attached device's descriptors, to determine compatibility and pipe configurations. This
  41  *  routine will read in the entire configuration descriptor, and configure the hosts pipes to correctly communicate
  42  *  with compatible devices.
  43  *
  44  *  This routine searches for a HID interface descriptor containing at least one Interrupt type IN endpoint and HID descriptor.
  45  *
  46  *  \return An error code from the \ref MouseHostWithParser_GetConfigDescriptorDataCodes_t enum.
  47  */
  48 uint8_t ProcessConfigurationDescriptor(void)
  49 {
  50         uint8_t  ConfigDescriptorData[512];
  51         void*    CurrConfigLocation = ConfigDescriptorData;
  52         uint16_t CurrConfigBytesRem;
  53
  54         USB_Descriptor_Endpoint_t* DataINEndpoint = NULL;
  55
  56         /* Retrieve the entire configuration descriptor into the allocated buffer */
  57         switch (USB_Host_GetDeviceConfigDescriptor(1, &CurrConfigBytesRem, ConfigDescriptorData, sizeof(ConfigDescriptorData)))
  58         {
  59                 case HOST_GETCONFIG_Successful:
  60                         break;
  61                 case HOST_GETCONFIG_InvalidData:
  62                         return InvalidConfigDataReturned;
  63                 case HOST_GETCONFIG_BuffOverflow:
  64                         return DescriptorTooLarge;
  65                 default:
  66                         return ControlError;
  67         }
  68
  69         /* Get the first HID interface from the configuration descriptor */
  70         if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
  71                                       DComp_NextMouseInterface) != DESCRIPTOR_SEARCH_COMP_Found)
  72         {
  73                 /* Descriptor not found, error out */
  74                 return NoCompatibleInterfaceFound;
  75         }
  76
  77         /* Get the HID descriptor from the configuration descriptor */
  78         if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
  79                                       DComp_NextHID) != DESCRIPTOR_SEARCH_COMP_Found)
  80         {
  81                 /* Descriptor not found, error out */
  82                 return NoCompatibleInterfaceFound;
  83         }
  84
  85         /* Save the HID report size for later use */
  86         HIDReportSize = DESCRIPTOR_CAST(CurrConfigLocation, USB_Descriptor_HID_t).HIDReportLength;
  87
  88         while (!(DataINEndpoint))
  89         {
  90                 /* Get the next HID interface's data endpoint descriptor */
  91                 if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
  92                                               DComp_NextMouseInterfaceDataEndpoint) != DESCRIPTOR_SEARCH_COMP_Found)
  93                 {
  94                         /* Get the next HID interface from the configuration descriptor */
  95                         if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
  96                                                                                   DComp_NextMouseInterface) != DESCRIPTOR_SEARCH_COMP_Found)
  97                         {
  98                                 /* Descriptor not found, error out */
  99                                 return NoCompatibleInterfaceFound;
 100                         }
 101
 102                         /* Get the HID descriptor from the configuration descriptor */
 103                         if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
 104                                                                                   DComp_NextHID) != DESCRIPTOR_SEARCH_COMP_Found)
 105                         {
 106                                 /* Descriptor not found, error out */
 107                                 return NoCompatibleInterfaceFound;
 108                         }
 109
 110                         /* Save the HID report size for later use */
 111                         HIDReportSize = DESCRIPTOR_CAST(CurrConfigLocation, USB_Descriptor_HID_t).HIDReportLength;
 112                 }
 113
 114                 /* Retrieve the endpoint address from the endpoint descriptor */
 115                 USB_Descriptor_Endpoint_t* EndpointData = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Endpoint_t);
 116
 117                 /* If the endpoint is a IN type endpoint */
 118                 if (EndpointData->EndpointAddress & ENDPOINT_DESCRIPTOR_DIR_IN)
 119                   DataINEndpoint = EndpointData;
 120         }
 121
 122         /* Configure the HID data IN pipe */
 123         Pipe_ConfigurePipe(MOUSE_DATA_IN_PIPE, EP_TYPE_INTERRUPT, PIPE_TOKEN_IN,
 124                            DataINEndpoint->EndpointAddress, DataINEndpoint->EndpointSize, PIPE_BANK_SINGLE);
 125         Pipe_SetInterruptPeriod(DataINEndpoint->PollingIntervalMS);
 126
 127         /* Valid data found, return success */
 128         return SuccessfulConfigRead;
 129 }
 130
 131 /** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's
 132  *  configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration
 133  *  descriptor processing if an incompatible descriptor configuration is found.
 134  *
 135  *  This comparator searches for the next Interface descriptor of the correct Mouse HID Class and Protocol values.
 136  *
 137  *  \return A value from the DSEARCH_Return_ErrorCodes_t enum
 138  */
 139 uint8_t DComp_NextMouseInterface(void* CurrentDescriptor)
 140 {
 141         if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Interface)
 142         {
 143                 /* Check the HID descriptor class and protocol, break out if correct class/protocol interface found */
 144                 if ((DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).Class    == MOUSE_CLASS) &&
 145                     (DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Interface_t).Protocol == MOUSE_PROTOCOL))
 146                 {
 147                         return DESCRIPTOR_SEARCH_Found;
 148                 }
 149         }
 150
 151         return DESCRIPTOR_SEARCH_NotFound;
 152 }
 153
 154 /** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's
 155  *  configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration
 156  *  descriptor processing if an incompatible descriptor configuration is found.
 157  *
 158  *  This comparator searches for the next IN Endpoint descriptor inside the current interface descriptor,
 159  *  aborting the search if another interface descriptor is found before the required endpoint.
 160  *
 161  *  \return A value from the DSEARCH_Return_ErrorCodes_t enum
 162  */
 163 uint8_t DComp_NextMouseInterfaceDataEndpoint(void* CurrentDescriptor)
 164 {
 165         if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Endpoint)
 166         {
 167                 if (DESCRIPTOR_CAST(CurrentDescriptor, USB_Descriptor_Endpoint_t).EndpointAddress & ENDPOINT_DESCRIPTOR_DIR_IN)
 168                   return DESCRIPTOR_SEARCH_Found;
 169         }
 170         else if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_Interface)
 171         {
 172                 return DESCRIPTOR_SEARCH_Fail;
 173         }
 174
 175         return DESCRIPTOR_SEARCH_NotFound;
 176 }
 177
 178 /** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's
 179  *  configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration
 180  *  descriptor processing if an incompatible descriptor configuration is found.
 181  *
 182  *  This comparator searches for the next HID descriptor within the current HID interface descriptor.
 183  *
 184  *  \return A value from the DSEARCH_Return_ErrorCodes_t enum
 185  */
 186 uint8_t DComp_NextHID(void* CurrentDescriptor)
 187 {
 188         if (DESCRIPTOR_TYPE(CurrentDescriptor) == DTYPE_HID)
 189           return DESCRIPTOR_SEARCH_Found;
 190         else
 191           return DESCRIPTOR_SEARCH_NotFound;
 192 }