3 Copyright (C) Dean Camera, 2014.
5 dean [at] fourwalledcubicle [dot] com
10 Copyright 2014 Dean Camera (dean [at] fourwalledcubicle [dot] com)
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.
21 The author disclaims 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
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.
38 #include "ConfigDescriptor.h"
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.
44 * This routine searches for a RNDIS interface descriptor containing bulk data IN and OUT endpoints, and an interrupt event endpoint.
46 * \return An error code from the \ref RNDISHost_GetConfigDescriptorDataCodes_t enum.
48 uint8_t ProcessConfigurationDescriptor(void)
50 uint8_t ConfigDescriptorData[512];
51 void* CurrConfigLocation = ConfigDescriptorData;
52 uint16_t CurrConfigBytesRem;
54 USB_Descriptor_Interface_t* RNDISControlInterface = NULL;
55 USB_Descriptor_Endpoint_t* DataINEndpoint = NULL;
56 USB_Descriptor_Endpoint_t* DataOUTEndpoint = NULL;
57 USB_Descriptor_Endpoint_t* NotificationEndpoint = NULL;
59 /* Retrieve the entire configuration descriptor into the allocated buffer */
60 switch (USB_Host_GetDeviceConfigDescriptor(1, &CurrConfigBytesRem, ConfigDescriptorData, sizeof(ConfigDescriptorData)))
62 case HOST_GETCONFIG_Successful:
64 case HOST_GETCONFIG_InvalidData:
65 return InvalidConfigDataReturned;
66 case HOST_GETCONFIG_BuffOverflow:
67 return DescriptorTooLarge;
72 while (!(DataINEndpoint) || !(DataOUTEndpoint) || !(NotificationEndpoint))
74 /* See if we've found a likely compatible interface, and if there is an endpoint within that interface */
75 if (!(RNDISControlInterface) ||
76 USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
77 DComp_NextCDCDataInterfaceEndpoint) != DESCRIPTOR_SEARCH_COMP_Found)
79 /* Check if we have already found the control interface's notification endpoint or not */
80 if (NotificationEndpoint)
82 /* Get the next RNDIS data interface from the configuration descriptor */
83 if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
84 DComp_NextCDCDataInterface) != DESCRIPTOR_SEARCH_COMP_Found)
86 /* Descriptor not found, error out */
87 return NoCompatibleInterfaceFound;
90 /* Clear any found endpoints */
91 DataINEndpoint = NULL;
92 DataOUTEndpoint = NULL;
96 /* Get the next RNDIS control interface from the configuration descriptor */
97 if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
98 DComp_NextCDCControlInterface) != DESCRIPTOR_SEARCH_COMP_Found)
100 /* Descriptor not found, error out */
101 return NoCompatibleInterfaceFound;
104 /* Save the interface in case we need to refer back to it later */
105 RNDISControlInterface = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t);
107 /* Clear any found endpoints */
108 NotificationEndpoint = NULL;
111 /* Skip the remainder of the loop as we have not found an endpoint yet */
115 /* Retrieve the endpoint address from the endpoint descriptor */
116 USB_Descriptor_Endpoint_t* EndpointData = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Endpoint_t);
118 /* If the endpoint is a IN type endpoint */
119 if ((EndpointData->EndpointAddress & ENDPOINT_DIR_MASK) == ENDPOINT_DIR_IN)
121 /* Check if the found endpoint is a interrupt or bulk type descriptor */
122 if ((EndpointData->Attributes & EP_TYPE_MASK) == EP_TYPE_INTERRUPT)
123 NotificationEndpoint = EndpointData;
125 DataINEndpoint = EndpointData;
129 DataOUTEndpoint = EndpointData;
133 /* Configure the RNDIS data IN pipe */
134 Pipe_ConfigurePipe(RNDIS_DATA_IN_PIPE, EP_TYPE_BULK, DataINEndpoint->EndpointAddress, DataINEndpoint->EndpointSize, 1);
136 /* Configure the RNDIS data OUT pipe */
137 Pipe_ConfigurePipe(RNDIS_DATA_OUT_PIPE, EP_TYPE_BULK, DataOUTEndpoint->EndpointAddress, DataOUTEndpoint->EndpointSize, 1);
139 /* Configure the RNDIS notification pipe */
140 Pipe_ConfigurePipe(RNDIS_NOTIFICATION_PIPE, EP_TYPE_INTERRUPT, NotificationEndpoint->EndpointAddress, NotificationEndpoint->EndpointSize, 1);
141 Pipe_SetInterruptPeriod(NotificationEndpoint->PollingIntervalMS);
143 /* Valid data found, return success */
144 return SuccessfulConfigRead;
147 /** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's
148 * configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration
149 * descriptor processing if an incompatible descriptor configuration is found.
151 * This comparator searches for the next Interface descriptor of the correct CDC control Class, Subclass and Protocol values.
153 * \return A value from the DSEARCH_Return_ErrorCodes_t enum
155 uint8_t DComp_NextCDCControlInterface(void* CurrentDescriptor)
157 USB_Descriptor_Header_t* Header = DESCRIPTOR_PCAST(CurrentDescriptor, USB_Descriptor_Header_t);
159 if (Header->Type == DTYPE_Interface)
161 USB_Descriptor_Interface_t* Interface = DESCRIPTOR_PCAST(CurrentDescriptor, USB_Descriptor_Interface_t);
163 /* Check the CDC descriptor class, subclass and protocol, break out if correct control interface found */
164 if ((Interface->Class == CDC_CSCP_CDCClass) &&
165 (Interface->SubClass == CDC_CSCP_ACMSubclass) &&
166 (Interface->Protocol == CDC_CSCP_VendorSpecificProtocol))
168 return DESCRIPTOR_SEARCH_Found;
172 return DESCRIPTOR_SEARCH_NotFound;
175 /** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's
176 * configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration
177 * descriptor processing if an incompatible descriptor configuration is found.
179 * This comparator searches for the next Interface descriptor of the correct CDC data Class, Subclass and Protocol values.
181 * \return A value from the DSEARCH_Return_ErrorCodes_t enum
183 uint8_t DComp_NextCDCDataInterface(void* CurrentDescriptor)
185 USB_Descriptor_Header_t* Header = DESCRIPTOR_PCAST(CurrentDescriptor, USB_Descriptor_Header_t);
187 if (Header->Type == DTYPE_Interface)
189 USB_Descriptor_Interface_t* Interface = DESCRIPTOR_PCAST(CurrentDescriptor, USB_Descriptor_Interface_t);
191 /* Check the CDC descriptor class, subclass and protocol, break out if correct data interface found */
192 if ((Interface->Class == CDC_CSCP_CDCDataClass) &&
193 (Interface->SubClass == CDC_CSCP_NoDataSubclass) &&
194 (Interface->Protocol == CDC_CSCP_NoDataProtocol))
196 return DESCRIPTOR_SEARCH_Found;
200 return DESCRIPTOR_SEARCH_NotFound;
203 /** Descriptor comparator function. This comparator function is can be called while processing an attached USB device's
204 * configuration descriptor, to search for a specific sub descriptor. It can also be used to abort the configuration
205 * descriptor processing if an incompatible descriptor configuration is found.
207 * This comparator searches for the next bulk IN or OUT endpoint, or interrupt IN endpoint within the current interface,
208 * aborting the search if another interface descriptor is found before the required endpoint (so that it may be compared
209 * using a different comparator to determine if it is another CDC class interface).
211 * \return A value from the DSEARCH_Return_ErrorCodes_t enum
213 uint8_t DComp_NextCDCDataInterfaceEndpoint(void* CurrentDescriptor)
215 USB_Descriptor_Header_t* Header = DESCRIPTOR_PCAST(CurrentDescriptor, USB_Descriptor_Header_t);
217 if (Header->Type == DTYPE_Endpoint)
219 USB_Descriptor_Endpoint_t* Endpoint = DESCRIPTOR_PCAST(CurrentDescriptor, USB_Descriptor_Endpoint_t);
221 /* Check the endpoint type, break out if correct BULK or INTERRUPT type endpoint found */
222 if (((Endpoint->Attributes & EP_TYPE_MASK) == EP_TYPE_BULK) ||
223 ((Endpoint->Attributes & EP_TYPE_MASK) == EP_TYPE_INTERRUPT))
225 return DESCRIPTOR_SEARCH_Found;
228 else if (Header->Type == DTYPE_Interface)
230 return DESCRIPTOR_SEARCH_Fail;
233 return DESCRIPTOR_SEARCH_NotFound;