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 /** CDC ACM 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_cdc_acm.h"
29 #include "ux_host_stack.h"
30
31
32 /**************************************************************************/
33 /* */
34 /* FUNCTION RELEASE */
35 /* */
36 /* _ux_host_class_cdc_acm_capabilities_get PORTABLE C */
37 /* 6.2.1 */
38 /* AUTHOR */
39 /* */
40 /* Chaoqiong Xiao, Microsoft Corporation */
41 /* */
42 /* DESCRIPTION */
43 /* */
44 /* This function obtains the entire cdc_acm configuration descriptors. */
45 /* This is needed because the cdc_acm class needs to know if commands */
46 /* are routed through the comm interface or the data class. */
47 /* */
48 /* INPUT */
49 /* */
50 /* cdc_acm Pointer to cdc_acm class */
51 /* */
52 /* OUTPUT */
53 /* */
54 /* Completion Status */
55 /* */
56 /* CALLS */
57 /* */
58 /* _ux_host_stack_transfer_request Process transfer request */
59 /* _ux_utility_descriptor_parse Parse descriptor */
60 /* _ux_utility_memory_allocate Allocate memory block */
61 /* _ux_utility_memory_free Release memory block */
62 /* */
63 /* CALLED BY */
64 /* */
65 /* _ux_host_class_cdc_acm_activate */
66 /* */
67 /* RELEASE HISTORY */
68 /* */
69 /* DATE NAME DESCRIPTION */
70 /* */
71 /* 05-19-2020 Chaoqiong Xiao Initial Version 6.0 */
72 /* 09-30-2020 Chaoqiong Xiao Modified comment(s), */
73 /* resulting in version 6.1 */
74 /* 03-08-2023 Chaoqiong Xiao Modified comment(s), */
75 /* fixed capabilities get from */
76 /* multiple CDC-ACM functions, */
77 /* resulting in version 6.2.1 */
78 /* */
79 /**************************************************************************/
_ux_host_class_cdc_acm_capabilities_get(UX_HOST_CLASS_CDC_ACM * cdc_acm)80 UINT _ux_host_class_cdc_acm_capabilities_get(UX_HOST_CLASS_CDC_ACM *cdc_acm)
81 {
82
83 UCHAR *descriptor;
84 UCHAR *saved_descriptor;
85 UX_ENDPOINT *control_endpoint;
86 UX_TRANSFER *transfer_request;
87 UX_CONFIGURATION configuration;
88 UX_INTERFACE_DESCRIPTOR interface_descriptor;
89 UINT status;
90 ULONG total_descriptor_length;
91 UCHAR descriptor_length;
92 UCHAR descriptor_type;
93 UCHAR descriptor_subtype;
94 ULONG interface_found;
95
96 /* We need to get the default control endpoint transfer request pointer. */
97 control_endpoint = &cdc_acm -> ux_host_class_cdc_acm_device -> ux_device_control_endpoint;
98 transfer_request = &control_endpoint -> ux_endpoint_transfer_request;
99
100 /* Need to allocate memory for the descriptor. */
101 descriptor = _ux_utility_memory_allocate(UX_SAFE_ALIGN, UX_CACHE_SAFE_MEMORY, UX_CONFIGURATION_DESCRIPTOR_LENGTH);
102 if (descriptor == UX_NULL)
103 return(UX_MEMORY_INSUFFICIENT);
104
105 /* Save this descriptor address since we need to free it. */
106 saved_descriptor = descriptor;
107
108 /* Create a transfer request for the GET_DESCRIPTOR request. */
109 transfer_request -> ux_transfer_request_data_pointer = descriptor;
110 transfer_request -> ux_transfer_request_requested_length = UX_CONFIGURATION_DESCRIPTOR_LENGTH;
111 transfer_request -> ux_transfer_request_function = UX_GET_DESCRIPTOR;
112 transfer_request -> ux_transfer_request_type = UX_REQUEST_IN | UX_REQUEST_TYPE_STANDARD | UX_REQUEST_TARGET_DEVICE;
113 transfer_request -> ux_transfer_request_value = UX_CONFIGURATION_DESCRIPTOR_ITEM << 8;
114 transfer_request -> ux_transfer_request_index = 0;
115
116 /* Send request to HCD layer. */
117 status = _ux_host_stack_transfer_request(transfer_request);
118
119 /* Check for correct transfer and entire descriptor returned. */
120 if ((status == UX_SUCCESS) && (transfer_request -> ux_transfer_request_actual_length == UX_CONFIGURATION_DESCRIPTOR_LENGTH))
121 {
122
123 /* The descriptor is in a packed format, parse it locally. */
124 _ux_utility_descriptor_parse(descriptor, _ux_system_configuration_descriptor_structure,
125 UX_CONFIGURATION_DESCRIPTOR_ENTRIES, (UCHAR *) &configuration.ux_configuration_descriptor);
126
127 /* Now we have the configuration descriptor which will tell us how many
128 bytes there are in the entire descriptor. */
129 total_descriptor_length = configuration.ux_configuration_descriptor.wTotalLength;
130
131 /* Free the previous descriptor. */
132 _ux_utility_memory_free(descriptor);
133
134 /* Allocate enough memory to read all descriptors attached
135 to this configuration. */
136 descriptor = _ux_utility_memory_allocate(UX_SAFE_ALIGN, UX_CACHE_SAFE_MEMORY, total_descriptor_length);
137 if (descriptor == UX_NULL)
138 return(UX_MEMORY_INSUFFICIENT);
139
140 /* Save this descriptor address since we need to free it. */
141 saved_descriptor = descriptor;
142
143 /* Set the length we need to retrieve. */
144 transfer_request -> ux_transfer_request_requested_length = total_descriptor_length;
145
146 /* And reprogram the descriptor buffer address. */
147 transfer_request -> ux_transfer_request_data_pointer = descriptor;
148
149 /* Send request to HCD layer. */
150 status = _ux_host_stack_transfer_request(transfer_request);
151
152 /* Check for correct transfer and entire descriptor returned. */
153 if ((status == UX_SUCCESS) && (transfer_request -> ux_transfer_request_actual_length == total_descriptor_length))
154 {
155
156 /* Default is Interface descriptor not yet found. */
157 interface_found = UX_FALSE;
158
159 /* Scan the descriptor for the CDC Comm interface. */
160 while (total_descriptor_length)
161 {
162
163 /* Gather the length, type and subtype of the descriptor. */
164 descriptor_length = *descriptor;
165 descriptor_type = *(descriptor + 1);
166 descriptor_subtype = *(descriptor + 2);
167
168 /* Make sure this descriptor has at least the minimum length. */
169 if (descriptor_length < 3)
170 {
171
172 /* Error trap. */
173 _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_DESCRIPTOR_CORRUPTED);
174
175 /* If trace is enabled, insert this event into the trace buffer. */
176 UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_DESCRIPTOR_CORRUPTED, descriptor, 0, 0, UX_TRACE_ERRORS, 0, 0)
177
178 /* We can free the resource now. */
179 _ux_utility_memory_free(saved_descriptor);
180
181 /* Descriptor is corrupted. */
182 return(UX_DESCRIPTOR_CORRUPTED);
183 }
184
185 /* Process relative to descriptor type. */
186 switch (descriptor_type)
187 {
188
189
190 case UX_INTERFACE_DESCRIPTOR_ITEM:
191
192 /* Parse the interface descriptor and make it machine independent. */
193 _ux_utility_descriptor_parse(descriptor, _ux_system_interface_descriptor_structure,
194 UX_INTERFACE_DESCRIPTOR_ENTRIES, (UCHAR *) &interface_descriptor);
195
196 /* Ensure we have the correct interface for CDC control (current interface). */
197 if (interface_descriptor.bInterfaceNumber ==
198 cdc_acm -> ux_host_class_cdc_acm_interface ->
199 ux_interface_descriptor.bInterfaceNumber)
200 {
201
202 /* Mark we have found it. */
203 interface_found = UX_TRUE;
204
205 }
206 else
207 {
208
209 /* Haven't found it. */
210 interface_found = UX_FALSE;
211 }
212 break;
213
214
215 case UX_HOST_CLASS_CDC_ACM_CS_INTERFACE:
216
217 /* First make sure we have found the correct generic interface descriptor. */
218 if ((interface_found == UX_TRUE) && (descriptor_subtype == UX_HOST_CLASS_CDC_ACM_CALL_MANAGEMENT_DESCRIPTOR))
219 {
220
221 /* Retrieve the bmCapabilities field which indicates how ACM commands are sent to the device. */
222 cdc_acm -> ux_host_class_cdc_acm_capabilities = *(descriptor + UX_HOST_CLASS_CDC_ACM_CALL_MANAGEMENT_CAPABILITIES);
223
224
225 }
226 break;
227 }
228
229 /* Verify if the descriptor is still valid. */
230 if (descriptor_length > total_descriptor_length)
231 {
232
233 /* Error trap. */
234 _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_DESCRIPTOR_CORRUPTED);
235
236 /* If trace is enabled, insert this event into the trace buffer. */
237 UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_DESCRIPTOR_CORRUPTED, descriptor, 0, 0, UX_TRACE_ERRORS, 0, 0)
238
239 /* We can free the resource now. */
240 _ux_utility_memory_free(saved_descriptor);
241
242 return(UX_DESCRIPTOR_CORRUPTED);
243 }
244
245 /* Jump to the next descriptor if we have not reached the end. */
246 descriptor += descriptor_length;
247
248 /* And adjust the length left to parse in the descriptor. */
249 total_descriptor_length -= descriptor_length;
250 }
251
252 /* We can free the resource now. */
253 _ux_utility_memory_free(saved_descriptor);
254
255 return(UX_SUCCESS);
256 }
257 }
258
259 /* Free all used resources. */
260 _ux_utility_memory_free(saved_descriptor);
261
262 /* Return completion status. */
263 return(status);
264 }
265
266
