1 /**************************************************************************/
2 /* */
3 /* Copyright (c) Microsoft Corporation. All rights reserved. */
4 /* */
5 /* This software is licensed under the Microsoft Software License */
6 /* Terms for Microsoft Azure RTOS. Full text of the license can be */
7 /* found in the LICENSE file at https://aka.ms/AzureRTOS_EULA */
8 /* and in the root directory of this software. */
9 /* */
10 /**************************************************************************/
11
12
13 /**************************************************************************/
14 /**************************************************************************/
15 /** */
16 /** USBX Component */
17 /** */
18 /** Audio Class */
19 /** */
20 /**************************************************************************/
21 /**************************************************************************/
22
23
24 /* Include necessary system files. */
25
26 #define UX_SOURCE_CODE
27
28 #include "ux_api.h"
29 #include "ux_host_class_audio.h"
30 #include "ux_host_stack.h"
31
32
33 /**************************************************************************/
34 /* */
35 /* FUNCTION RELEASE */
36 /* */
37 /* _ux_host_class_audio_streaming_terminal_get PORTABLE C */
38 /* 6.1 */
39 /* AUTHOR */
40 /* */
41 /* Chaoqiong Xiao, Microsoft Corporation */
42 /* */
43 /* DESCRIPTION */
44 /* */
45 /* This function searches and retrieves the streaming terminal. This */
46 /* terminal is used to further search which of the input\output */
47 /* terminals describes if the device is audio IN or audio OUT. */
48 /* */
49 /* INPUT */
50 /* */
51 /* audio Pointer to audio class */
52 /* */
53 /* OUTPUT */
54 /* */
55 /* Completion Status */
56 /* */
57 /* CALLS */
58 /* */
59 /* _ux_utility_descriptor_parse Parse descriptor */
60 /* */
61 /* CALLED BY */
62 /* */
63 /* Audio Class */
64 /* */
65 /* RELEASE HISTORY */
66 /* */
67 /* DATE NAME DESCRIPTION */
68 /* */
69 /* 05-19-2020 Chaoqiong Xiao Initial Version 6.0 */
70 /* 09-30-2020 Chaoqiong Xiao Modified comment(s), */
71 /* resulting in version 6.1 */
72 /* */
73 /**************************************************************************/
_ux_host_class_audio_streaming_terminal_get(UX_HOST_CLASS_AUDIO * audio)74 UINT _ux_host_class_audio_streaming_terminal_get(UX_HOST_CLASS_AUDIO *audio)
75 {
76
77 UCHAR * descriptor;
78 UX_INTERFACE_DESCRIPTOR interface_descriptor;
79 UX_HOST_CLASS_AUDIO_STREAMING_INTERFACE_DESCRIPTOR streaming_interface_descriptor;
80 ULONG total_descriptor_length;
81 ULONG descriptor_length;
82 ULONG descriptor_type;
83 ULONG descriptor_subtype;
84 ULONG descriptor_found;
85
86
87 /* Get the descriptor to the entire configuration */
88 descriptor = audio -> ux_host_class_audio_configuration_descriptor;
89 total_descriptor_length = audio -> ux_host_class_audio_configuration_descriptor_length;
90
91 /* Default is Interface descriptor not yet found. */
92 descriptor_found = UX_FALSE;
93 audio -> ux_host_class_audio_terminal_link = 0xffffffff;
94
95 /* Scan the descriptor for the Audio Streaming interface. */
96 while (total_descriptor_length)
97 {
98
99 /* Gather the length, type and subtype of the descriptor. */
100 descriptor_length = *descriptor;
101 descriptor_type = *(descriptor + 1);
102 descriptor_subtype = *(descriptor + 2);
103
104 /* Make sure this descriptor has at least the minimum length. */
105 if (descriptor_length < 3)
106 {
107
108 /* Error trap. */
109 _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_DESCRIPTOR_CORRUPTED);
110
111 /* If trace is enabled, insert this event into the trace buffer. */
112 UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_DESCRIPTOR_CORRUPTED, descriptor, 0, 0, UX_TRACE_ERRORS, 0, 0)
113
114 return(UX_DESCRIPTOR_CORRUPTED);
115 }
116
117 /* Process relative to the descriptor type. */
118 switch(descriptor_type)
119 {
120
121
122 case UX_INTERFACE_DESCRIPTOR_ITEM:
123
124 /* Parse the interface descriptor and make it machine independent. */
125 _ux_utility_descriptor_parse(descriptor, _ux_system_interface_descriptor_structure,
126 UX_INTERFACE_DESCRIPTOR_ENTRIES, (UCHAR *) &interface_descriptor);
127
128 /* Ensure we have the correct interface for Audio streaming. */
129 if ((interface_descriptor.bInterfaceClass == UX_HOST_CLASS_AUDIO_CLASS) &&
130 (interface_descriptor.bInterfaceSubClass == UX_HOST_CLASS_AUDIO_SUBCLASS_STREAMING) &&
131 (interface_descriptor.bInterfaceNumber == audio -> ux_host_class_audio_streaming_interface -> ux_interface_descriptor.bInterfaceNumber))
132
133 /* Mark we have found it. */
134 descriptor_found = UX_TRUE;
135 else
136
137 descriptor_found = UX_FALSE;
138 break;
139
140
141 case UX_HOST_CLASS_AUDIO_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_AUDIO_CS_AS_GENERAL:
153
154 /* Make the descriptor machine independent. */
155 _ux_utility_descriptor_parse(descriptor, _ux_system_class_audio_streaming_interface_descriptor_structure,
156 UX_HOST_CLASS_AUDIO_STREAMING_INTERFACE_DESCRIPTOR_ENTRIES, (UCHAR *) &streaming_interface_descriptor);
157
158 /* Save the terminal link. */
159 audio -> ux_host_class_audio_terminal_link = streaming_interface_descriptor.bTerminalLink;
160 return(UX_SUCCESS);
161 }
162 }
163 break;
164 }
165
166 /* Verify if the descriptor is still valid. */
167 if (descriptor_length > total_descriptor_length)
168 {
169
170 /* Error trap. */
171 _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_DESCRIPTOR_CORRUPTED);
172
173 /* If trace is enabled, insert this event into the trace buffer. */
174 UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_DESCRIPTOR_CORRUPTED, descriptor, 0, 0, UX_TRACE_ERRORS, 0, 0)
175
176 return(UX_DESCRIPTOR_CORRUPTED);
177 }
178
179 /* Jump to the next descriptor if we have not reached the end. */
180 descriptor += descriptor_length;
181
182 /* And adjust the length left to parse in the descriptor. */
183 total_descriptor_length -= descriptor_length;
184 }
185
186 /* Error trap. */
187 _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_HOST_CLASS_AUDIO_WRONG_TYPE);
188
189 /* We get here when either the report descriptor has a problem or we could
190 not find the right audio device. */
191 return(UX_HOST_CLASS_AUDIO_WRONG_TYPE);
192 }
193
194
