1 /***************************************************************************
2 * Copyright (c) 2024 Microsoft Corporation
3 *
4 * This program and the accompanying materials are made available under the
5 * terms of the MIT License which is available at
6 * https://opensource.org/licenses/MIT.
7 *
8 * SPDX-License-Identifier: MIT
9 **************************************************************************/
10
11
12 /**************************************************************************/
13 /**************************************************************************/
14 /** */
15 /** USBX Component */
16 /** */
17 /** Video Class */
18 /** */
19 /**************************************************************************/
20 /**************************************************************************/
21
22
23 /* Include necessary system files. */
24
25 #define UX_SOURCE_CODE
26
27 #include "ux_api.h"
28 #include "ux_host_class_video.h"
29 #include "ux_host_stack.h"
30
31
32 /**************************************************************************/
33 /* */
34 /* FUNCTION RELEASE */
35 /* */
36 /* _ux_host_class_video_input_format_get PORTABLE C */
37 /* 6.1 */
38 /* AUTHOR */
39 /* */
40 /* Chaoqiong Xiao, Microsoft Corporation */
41 /* */
42 /* DESCRIPTION */
43 /* */
44 /* This function finds the input format(s) for the input terminal. */
45 /* */
46 /* INPUT */
47 /* */
48 /* video Pointer to video class */
49 /* */
50 /* OUTPUT */
51 /* */
52 /* Completion Status */
53 /* */
54 /* CALLS */
55 /* */
56 /* _ux_utility_descriptor_parse Parse descriptor */
57 /* _ux_system_error_handler Log system error */
58 /* */
59 /* CALLED BY */
60 /* */
61 /* Video Class */
62 /* */
63 /* RELEASE HISTORY */
64 /* */
65 /* DATE NAME DESCRIPTION */
66 /* */
67 /* 05-19-2020 Chaoqiong Xiao Initial Version 6.0 */
68 /* 09-30-2020 Chaoqiong Xiao Modified comment(s), */
69 /* resulting in version 6.1 */
70 /* */
71 /**************************************************************************/
_ux_host_class_video_input_format_get(UX_HOST_CLASS_VIDEO * video)72 UINT _ux_host_class_video_input_format_get(UX_HOST_CLASS_VIDEO *video)
73 {
74
75 UCHAR *descriptor;
76 UX_INTERFACE_DESCRIPTOR interface_descriptor;
77 UX_HOST_CLASS_VIDEO_INPUT_HEADER_DESCRIPTOR input_header_descriptor;
78 ULONG total_descriptor_length;
79 ULONG descriptor_length;
80 ULONG descriptor_type;
81 ULONG descriptor_subtype;
82 ULONG descriptor_found;
83
84
85 /* Get the descriptor to the entire configuration. */
86 descriptor = video -> ux_host_class_video_configuration_descriptor;
87 total_descriptor_length = video -> ux_host_class_video_configuration_descriptor_length;
88
89 /* Default is Interface descriptor not yet found. */
90 descriptor_found = UX_FALSE;
91
92 /* Scan the descriptor for the Video Streaming interface. */
93 while (total_descriptor_length)
94 {
95
96 /* Gather the length, type and subtype of the descriptor. */
97 descriptor_length = *descriptor;
98 descriptor_type = *(descriptor + 1);
99 descriptor_subtype = *(descriptor + 2);
100
101 /* Make sure this descriptor has at least the minimum length. */
102 if (descriptor_length < 3)
103 {
104
105 /* Error trap. */
106 _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_DESCRIPTOR_CORRUPTED);
107
108 /* If trace is enabled, insert this event into the trace buffer. */
109 //UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_DESCRIPTOR_CORRUPTED, descriptor, 0, 0, UX_TRACE_ERRORS, 0, 0)
110
111 return(UX_DESCRIPTOR_CORRUPTED);
112 }
113
114 /* Process relative to the descriptor type. */
115 switch (descriptor_type)
116 {
117
118
119 case UX_INTERFACE_DESCRIPTOR_ITEM:
120
121 /* Parse the interface descriptor and make it machine independent. */
122 _ux_utility_descriptor_parse(descriptor, _ux_system_interface_descriptor_structure,
123 UX_INTERFACE_DESCRIPTOR_ENTRIES, (UCHAR *) &interface_descriptor);
124
125 /* Ensure we have the correct interface for Video Streaming. */
126 if ((interface_descriptor.bInterfaceClass == UX_HOST_CLASS_VIDEO_CLASS) &&
127 (interface_descriptor.bInterfaceSubClass == UX_HOST_CLASS_VIDEO_SUBCLASS_STREAMING))
128 {
129
130 /* Mark we have found it. */
131 descriptor_found = UX_TRUE;
132 }
133 else
134 {
135
136 descriptor_found = UX_FALSE;
137 }
138 break;
139
140
141 case UX_HOST_CLASS_VIDEO_CS_INTERFACE:
142
143 /* First make sure we have found the correct generic interface descriptor. */
144 if (descriptor_found == UX_TRUE)
145 {
146
147 /* Check the sub type. */
148 switch (descriptor_subtype)
149 {
150
151
152 case UX_HOST_CLASS_VIDEO_VS_INPUT_HEADER:
153
154 /* Make the descriptor machine independent. */
155 _ux_utility_descriptor_parse(descriptor, _ux_system_class_video_input_header_descriptor_structure,
156 UX_HOST_CLASS_VIDEO_INPUT_HEADER_DESCRIPTOR_ENTRIES, (UCHAR *) &input_header_descriptor);
157
158 /* Get the number of formats. */
159 video -> ux_host_class_video_number_formats = input_header_descriptor.bNumFormats;
160
161 /* Get the length of formats. */
162 video -> ux_host_class_video_length_formats = input_header_descriptor.wTotalLength;
163
164 /* Save the descriptor where the formats reside. */
165 video -> ux_host_class_video_format_address = descriptor;
166
167 /* We are done here. */
168 return(UX_SUCCESS);
169
170 }
171 }
172 break;
173 }
174
175 /* Verify if the descriptor is still valid. */
176 if (descriptor_length > total_descriptor_length)
177 {
178
179 /* Error trap. */
180 _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_DESCRIPTOR_CORRUPTED);
181
182 /* If trace is enabled, insert this event into the trace buffer. */
183 //UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_DESCRIPTOR_CORRUPTED, descriptor, 0, 0, UX_TRACE_ERRORS, 0, 0)
184
185 return(UX_DESCRIPTOR_CORRUPTED);
186 }
187
188 /* Jump to the next descriptor if we have not reached the end. */
189 descriptor += descriptor_length;
190
191 /* And adjust the length left to parse in the descriptor. */
192 total_descriptor_length -= descriptor_length;
193 }
194
195 /* Error trap. */
196 _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_HOST_CLASS_VIDEO_WRONG_TYPE);
197
198 /* We get here when either the report descriptor has a problem or we could
199 not find the right video device. */
200 return(UX_HOST_CLASS_VIDEO_WRONG_TYPE);
201 }
202
203
