ConfigDescriptor.c 7.09 KB
Newer Older
1
2
3
/*
             LUFA Library
     Copyright (C) Dean Camera, 2010.
4

5
  dean [at] fourwalledcubicle [dot] com
6
           www.lufa-lib.org
7
8
9
10
11
*/

/*
  Copyright 2010  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
17
18
  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
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
46
47
48
49
50
51
  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.
*/

#include "ConfigDescriptor.h"

/** Interface number for the bidirectional Printer interface found within the device. */
uint8_t PrinterInterfaceNumber;

/** Interface Alternate Setting number for the bidirectional Printer interface found within the device. */
uint8_t PrinterAltSetting;

/** 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 bidirectional Printer interface descriptor containing bulk IN and OUT data endpoints.
 *
 *  \return An error code from the \ref PrinterHost_GetConfigDescriptorDataCodes_t enum.
 */
uint8_t ProcessConfigurationDescriptor(void)
{
	uint8_t  ConfigDescriptorData[512];
	void*    CurrConfigLocation = ConfigDescriptorData;
	uint16_t CurrConfigBytesRem;
52

53
54
55
	USB_Descriptor_Interface_t* PrinterInterface = NULL;
	USB_Descriptor_Endpoint_t*  DataINEndpoint   = NULL;
	USB_Descriptor_Endpoint_t*  DataOUTEndpoint  = NULL;
56
57
58
59
60
61
62
63
64
65
66
67
68

	/* 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;
	}
69

70
	while (!(DataINEndpoint) || !(DataOUTEndpoint))
71
	{
72
73
74
		/* See if we've found a likely compatible interface, and if there is an endpoint within that interface */
		if (!(PrinterInterface) ||
		    USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
75
		                              DComp_NextPrinterInterfaceBulkDataEndpoint) != DESCRIPTOR_SEARCH_COMP_Found)
76
		{
77
78
79
80
81
82
83
			/* Get the next Printer interface from the configuration descriptor */
			if (USB_GetNextDescriptorComp(&CurrConfigBytesRem, &CurrConfigLocation,
										  DComp_NextBidirectionalPrinterInterface) != DESCRIPTOR_SEARCH_COMP_Found)
			{
				/* Descriptor not found, error out */
				return NoCompatibleInterfaceFound;
			}
84

85
86
87
88
89
90
			/* Save the interface in case we need to refer back to it later */
			PrinterInterface = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Interface_t);

			/* Clear any found endpoints */
			DataINEndpoint  = NULL;
			DataOUTEndpoint = NULL;
91
92
93

			/* Skip the remainder of the loop as we have not found an endpoint yet */
			continue;
94
		}
95

96
		/* Retrieve the endpoint address from the endpoint descriptor */
97
98
		USB_Descriptor_Endpoint_t* EndpointData = DESCRIPTOR_PCAST(CurrConfigLocation, USB_Descriptor_Endpoint_t);

99
		/* If the endpoint is a IN type endpoint */
100
		if (EndpointData->EndpointAddress & ENDPOINT_DESCRIPTOR_DIR_IN)
101
		  DataINEndpoint  = EndpointData;
102
		else
103
		  DataOUTEndpoint = EndpointData;
104
	}
105

106
107
	/* Save Printer interface details for later use */
	PrinterInterfaceNumber = PrinterInterface->InterfaceNumber;
108
	PrinterAltSetting      = PrinterInterface->AlternateSetting;
109

110
111
112
113
114
115
116
	/* Configure the Printer data IN pipe */
	Pipe_ConfigurePipe(PRINTER_DATA_IN_PIPE, EP_TYPE_BULK, PIPE_TOKEN_IN,
	                   DataINEndpoint->EndpointAddress, DataINEndpoint->EndpointSize, PIPE_BANK_SINGLE);

	/* Configure the Printer data OUT pipe */
	Pipe_ConfigurePipe(PRINTER_DATA_OUT_PIPE, EP_TYPE_BULK, PIPE_TOKEN_OUT,
					   DataOUTEndpoint->EndpointAddress, DataOUTEndpoint->EndpointSize, PIPE_BANK_SINGLE);
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132

	/* 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 Bidirectional Printer Interface descriptor of the current Printer interface,
 *  aborting the search if the end of the descriptors is found.
 *
 *  \return A value from the DSEARCH_Return_ErrorCodes_t enum
 */
uint8_t DComp_NextBidirectionalPrinterInterface(void* CurrentDescriptor)
{
133
134
135
	USB_Descriptor_Header_t* Header = DESCRIPTOR_PCAST(CurrentDescriptor, USB_Descriptor_Header_t);

	if (Header->Type == DTYPE_Interface)
136
	{
137
138
		USB_Descriptor_Interface_t* Interface = DESCRIPTOR_PCAST(CurrentDescriptor, USB_Descriptor_Interface_t);

139
		/* Check the descriptor class, subclass and protocol, break out if correct value interface found */
140
141
142
		if ((Interface->Class    == PRNT_CSCP_PrinterClass)    &&
		    (Interface->SubClass == PRNT_CSCP_PrinterSubclass) &&
			(Interface->Protocol == PRNT_CSCP_BidirectionalProtocol))
143
144
145
146
		{
			return DESCRIPTOR_SEARCH_Found;
		}
	}
147

148
149
150
151
152
153
154
155
156
157
158
159
160
161
	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 Endpoint descriptor of the current Printer interface, aborting the
 *  search if another interface descriptor is found before the next endpoint.
 *
 *  \return A value from the DSEARCH_Return_ErrorCodes_t enum
 */
uint8_t DComp_NextPrinterInterfaceBulkDataEndpoint(void* CurrentDescriptor)
{
162
163
164
	USB_Descriptor_Header_t* Header = DESCRIPTOR_PCAST(CurrentDescriptor, USB_Descriptor_Header_t);

	if (Header->Type == DTYPE_Endpoint)
165
	{
166
		USB_Descriptor_Endpoint_t* Endpoint = DESCRIPTOR_PCAST(CurrentDescriptor, USB_Descriptor_Endpoint_t);
167
168

		/* Check the endpoint type, break out if correct BULK type endpoint found */
169
		if ((Endpoint->Attributes & EP_TYPE_MASK) == EP_TYPE_BULK)
170
171
		  return DESCRIPTOR_SEARCH_Found;
	}
172
	else if (Header->Type == DTYPE_Interface)
173
174
175
176
177
178
	{
		return DESCRIPTOR_SEARCH_Fail;
	}

	return DESCRIPTOR_SEARCH_NotFound;
}
179