1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
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
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
|
/***************************************************************************
* Copyright (c) 2024 Microsoft Corporation
* Copyright (c) 2026-present Eclipse ThreadX contributors
*
* This program and the accompanying materials are made available under the
* terms of the MIT License which is available at
* https://opensource.org/licenses/MIT.
*
* SPDX-License-Identifier: MIT
**************************************************************************/
/**************************************************************************/
/**************************************************************************/
/** */
/** USBX Component */
/** */
/** CDC ACM Class */
/** */
/**************************************************************************/
/**************************************************************************/
/* Include necessary system files. */
#define UX_SOURCE_CODE
#include "ux_api.h"
#include "ux_host_class_cdc_acm.h"
#include "ux_host_stack.h"
/**************************************************************************/
/* */
/* FUNCTION RELEASE */
/* */
/* _ux_host_class_cdc_acm_capabilities_get PORTABLE C */
/* 6.2.1 */
/* AUTHOR */
/* */
/* Chaoqiong Xiao, Microsoft Corporation */
/* */
/* DESCRIPTION */
/* */
/* This function obtains the entire cdc_acm configuration descriptors. */
/* This is needed because the cdc_acm class needs to know if commands */
/* are routed through the comm interface or the data class. */
/* */
/* INPUT */
/* */
/* cdc_acm Pointer to cdc_acm class */
/* */
/* OUTPUT */
/* */
/* Completion Status */
/* */
/* CALLS */
/* */
/* _ux_host_stack_transfer_request Process transfer request */
/* _ux_utility_descriptor_parse Parse descriptor */
/* _ux_utility_memory_allocate Allocate memory block */
/* _ux_utility_memory_free Release memory block */
/* */
/* CALLED BY */
/* */
/* _ux_host_class_cdc_acm_activate */
/* */
/**************************************************************************/
UINT _ux_host_class_cdc_acm_capabilities_get(UX_HOST_CLASS_CDC_ACM *cdc_acm)
{
UCHAR *descriptor;
UCHAR *saved_descriptor;
UX_ENDPOINT *control_endpoint;
UX_TRANSFER *transfer_request;
UX_CONFIGURATION configuration;
UX_INTERFACE_DESCRIPTOR interface_descriptor;
UINT status;
ULONG total_descriptor_length;
UCHAR descriptor_length;
UCHAR descriptor_type;
UCHAR descriptor_subtype;
ULONG interface_found;
/* We need to get the default control endpoint transfer request pointer. */
control_endpoint = &cdc_acm -> ux_host_class_cdc_acm_device -> ux_device_control_endpoint;
transfer_request = &control_endpoint -> ux_endpoint_transfer_request;
/* Need to allocate memory for the descriptor. */
descriptor = _ux_utility_memory_allocate(UX_SAFE_ALIGN, UX_CACHE_SAFE_MEMORY, UX_CONFIGURATION_DESCRIPTOR_LENGTH);
if (descriptor == UX_NULL)
return(UX_MEMORY_INSUFFICIENT);
/* Save this descriptor address since we need to free it. */
saved_descriptor = descriptor;
/* Create a transfer request for the GET_DESCRIPTOR request. */
transfer_request -> ux_transfer_request_data_pointer = descriptor;
transfer_request -> ux_transfer_request_requested_length = UX_CONFIGURATION_DESCRIPTOR_LENGTH;
transfer_request -> ux_transfer_request_function = UX_GET_DESCRIPTOR;
transfer_request -> ux_transfer_request_type = UX_REQUEST_IN | UX_REQUEST_TYPE_STANDARD | UX_REQUEST_TARGET_DEVICE;
transfer_request -> ux_transfer_request_value = UX_CONFIGURATION_DESCRIPTOR_ITEM << 8;
transfer_request -> ux_transfer_request_index = 0;
/* Send request to HCD layer. */
status = _ux_host_stack_transfer_request(transfer_request);
/* Check for correct transfer and entire descriptor returned. */
if ((status == UX_SUCCESS) && (transfer_request -> ux_transfer_request_actual_length == UX_CONFIGURATION_DESCRIPTOR_LENGTH))
{
/* The descriptor is in a packed format, parse it locally. */
_ux_utility_descriptor_parse(descriptor, _ux_system_configuration_descriptor_structure,
UX_CONFIGURATION_DESCRIPTOR_ENTRIES, (UCHAR *) &configuration.ux_configuration_descriptor);
/* Now we have the configuration descriptor which will tell us how many
bytes there are in the entire descriptor. */
total_descriptor_length = configuration.ux_configuration_descriptor.wTotalLength;
/* Free the previous descriptor. */
_ux_utility_memory_free(descriptor);
/* Allocate enough memory to read all descriptors attached
to this configuration. */
descriptor = _ux_utility_memory_allocate(UX_SAFE_ALIGN, UX_CACHE_SAFE_MEMORY, total_descriptor_length);
if (descriptor == UX_NULL)
return(UX_MEMORY_INSUFFICIENT);
/* Save this descriptor address since we need to free it. */
saved_descriptor = descriptor;
/* Set the length we need to retrieve. */
transfer_request -> ux_transfer_request_requested_length = total_descriptor_length;
/* And reprogram the descriptor buffer address. */
transfer_request -> ux_transfer_request_data_pointer = descriptor;
/* Send request to HCD layer. */
status = _ux_host_stack_transfer_request(transfer_request);
/* Check for correct transfer and entire descriptor returned. */
if ((status == UX_SUCCESS) && (transfer_request -> ux_transfer_request_actual_length == total_descriptor_length))
{
/* Default is Interface descriptor not yet found. */
interface_found = UX_FALSE;
/* Scan the descriptor for the CDC Comm interface. */
while (total_descriptor_length)
{
/* Gather the length, type and subtype of the descriptor. */
descriptor_length = *descriptor;
descriptor_type = *(descriptor + 1);
descriptor_subtype = *(descriptor + 2);
/* Make sure this descriptor has at least the minimum length. */
if (descriptor_length < 3)
{
/* Error trap. */
_ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_DESCRIPTOR_CORRUPTED);
/* If trace is enabled, insert this event into the trace buffer. */
UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_DESCRIPTOR_CORRUPTED, descriptor, 0, 0, UX_TRACE_ERRORS, 0, 0)
/* We can free the resource now. */
_ux_utility_memory_free(saved_descriptor);
/* Descriptor is corrupted. */
return(UX_DESCRIPTOR_CORRUPTED);
}
/* Process relative to descriptor type. */
switch (descriptor_type)
{
case UX_INTERFACE_DESCRIPTOR_ITEM:
/* Parse the interface descriptor and make it machine independent. */
_ux_utility_descriptor_parse(descriptor, _ux_system_interface_descriptor_structure,
UX_INTERFACE_DESCRIPTOR_ENTRIES, (UCHAR *) &interface_descriptor);
/* Ensure we have the correct interface for CDC control (current interface). */
if (interface_descriptor.bInterfaceNumber ==
cdc_acm -> ux_host_class_cdc_acm_interface ->
ux_interface_descriptor.bInterfaceNumber)
{
/* Mark we have found it. */
interface_found = UX_TRUE;
}
else
{
/* Haven't found it. */
interface_found = UX_FALSE;
}
break;
case UX_HOST_CLASS_CDC_ACM_CS_INTERFACE:
/* First make sure we have found the correct generic interface descriptor. */
if ((interface_found == UX_TRUE) && (descriptor_subtype == UX_HOST_CLASS_CDC_ACM_CALL_MANAGEMENT_DESCRIPTOR))
{
/* Retrieve the bmCapabilities field which indicates how ACM commands are sent to the device. */
cdc_acm -> ux_host_class_cdc_acm_capabilities = *(descriptor + UX_HOST_CLASS_CDC_ACM_CALL_MANAGEMENT_CAPABILITIES);
}
break;
}
/* Verify if the descriptor is still valid. */
if (descriptor_length > total_descriptor_length)
{
/* Error trap. */
_ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_DESCRIPTOR_CORRUPTED);
/* If trace is enabled, insert this event into the trace buffer. */
UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_DESCRIPTOR_CORRUPTED, descriptor, 0, 0, UX_TRACE_ERRORS, 0, 0)
/* We can free the resource now. */
_ux_utility_memory_free(saved_descriptor);
return(UX_DESCRIPTOR_CORRUPTED);
}
/* Jump to the next descriptor if we have not reached the end. */
descriptor += descriptor_length;
/* And adjust the length left to parse in the descriptor. */
total_descriptor_length -= descriptor_length;
}
/* We can free the resource now. */
_ux_utility_memory_free(saved_descriptor);
return(UX_SUCCESS);
}
}
/* Free all used resources. */
_ux_utility_memory_free(saved_descriptor);
/* Return completion status. */
return(status);
}
|
