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 /** HID 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_hid.h"
29 #include "ux_host_stack.h"
30
31
32 /**************************************************************************/
33 /* */
34 /* FUNCTION RELEASE */
35 /* */
36 /* _ux_host_class_hid_descriptor_parse PORTABLE C */
37 /* 6.1.12 */
38 /* AUTHOR */
39 /* */
40 /* Chaoqiong Xiao, Microsoft Corporation */
41 /* */
42 /* DESCRIPTION */
43 /* */
44 /* This function obtains the HID descriptor and parses it. */
45 /* */
46 /* INPUT */
47 /* */
48 /* hid Pointer to HID class */
49 /* */
50 /* OUTPUT */
51 /* */
52 /* Completion Status */
53 /* */
54 /* CALLS */
55 /* */
56 /* _ux_host_class_hid_report_descriptor_get */
57 /* Get HID report descriptor */
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 /* HID Class */
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 /* 07-29-2022 Chaoqiong Xiao Modified comment(s), */
75 /* used shared device config */
76 /* descriptor for enum scan, */
77 /* resulting in version 6.1.12 */
78 /* */
79 /**************************************************************************/
_ux_host_class_hid_descriptor_parse(UX_HOST_CLASS_HID * hid)80 UINT _ux_host_class_hid_descriptor_parse(UX_HOST_CLASS_HID *hid)
81 {
82
83 UX_DEVICE *device;
84 UX_CONFIGURATION *configuration;
85 UCHAR *descriptor;
86 UCHAR *start_descriptor;
87 UX_ENDPOINT *control_endpoint;
88 UX_TRANSFER *transfer_request;
89 UX_HID_DESCRIPTOR hid_descriptor;
90 UX_INTERFACE_DESCRIPTOR interface_descriptor;
91 UINT status;
92 ULONG total_configuration_length;
93 UINT descriptor_length;
94 UINT descriptor_type;
95 ULONG current_interface;
96
97 /* Get device, current configuration. */
98 device = hid -> ux_host_class_hid_device;
99 configuration = device -> ux_device_current_configuration;
100 total_configuration_length = configuration -> ux_configuration_descriptor.wTotalLength;
101
102 /* Check if descriptor is previously saved. */
103 if (device -> ux_device_packed_configuration != UX_NULL)
104 {
105 start_descriptor = device -> ux_device_packed_configuration;
106 descriptor = start_descriptor;
107 status = UX_SUCCESS;
108 }
109 else
110 {
111
112 /* We need to get the default control endpoint transfer request pointer. */
113 control_endpoint = &device -> ux_device_control_endpoint;
114 transfer_request = &control_endpoint -> ux_endpoint_transfer_request;
115
116 /* Need to allocate memory for the descriptor. Since we do not know the size of the
117 descriptor, we first read the first bytes. */
118 descriptor = _ux_utility_memory_allocate(UX_SAFE_ALIGN, UX_CACHE_SAFE_MEMORY, total_configuration_length);
119 if (descriptor == UX_NULL)
120 return(UX_MEMORY_INSUFFICIENT);
121
122 /* Memorize the descriptor start address. */
123 start_descriptor = descriptor;
124
125 /* Create a transfer request for the GET_DESCRIPTOR request. */
126 transfer_request -> ux_transfer_request_data_pointer = descriptor;
127 transfer_request -> ux_transfer_request_requested_length = total_configuration_length;
128 transfer_request -> ux_transfer_request_function = UX_GET_DESCRIPTOR;
129 transfer_request -> ux_transfer_request_type = UX_REQUEST_IN | UX_REQUEST_TYPE_STANDARD | UX_REQUEST_TARGET_DEVICE;
130 transfer_request -> ux_transfer_request_value = UX_CONFIGURATION_DESCRIPTOR_ITEM << 8;
131 transfer_request -> ux_transfer_request_index = 0;
132
133 /* Send request to HCD layer. */
134 status = _ux_host_stack_transfer_request(transfer_request);
135
136 /* Check descriptor length. */
137 if (transfer_request -> ux_transfer_request_actual_length != total_configuration_length)
138 status = UX_DESCRIPTOR_CORRUPTED;
139 }
140
141 /* Reset the current interface to keep compiler warnings happy. */
142 current_interface = 0;
143
144 /* Check for correct transfer and entire descriptor returned. */
145 if (status == UX_SUCCESS)
146 {
147
148 /* The HID descriptor is embedded within the configuration descriptor. We parse the
149 entire descriptor to locate the HID portion. */
150 while (total_configuration_length)
151 {
152
153 /* Gather the length and type of the descriptor. */
154 descriptor_length = *descriptor;
155 descriptor_type = *(descriptor + 1);
156
157 /* Make sure this descriptor has at least the minimum length. */
158 if (descriptor_length < 3)
159 {
160
161 /* Error trap. */
162 _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_DESCRIPTOR_CORRUPTED);
163
164 /* If trace is enabled, insert this event into the trace buffer. */
165 UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_DESCRIPTOR_CORRUPTED, descriptor, 0, 0, UX_TRACE_ERRORS, 0, 0)
166
167 /* Error, release the memory and return an error. */
168 _ux_utility_memory_free(start_descriptor);
169
170 return(UX_DESCRIPTOR_CORRUPTED);
171 }
172
173 /* Check the type for an interface descriptor. */
174 if (descriptor_type == UX_INTERFACE_DESCRIPTOR_ITEM)
175 {
176
177 /* Parse the interface descriptor and make it machine independent. */
178 _ux_utility_descriptor_parse(descriptor,
179 _ux_system_interface_descriptor_structure,
180 UX_INTERFACE_DESCRIPTOR_ENTRIES,
181 (UCHAR *) &interface_descriptor);
182
183 /* Memorize the interface we are scanning. */
184 current_interface = interface_descriptor.bInterfaceNumber;
185 }
186
187 /* Check the type for an interface descriptor. */
188 /* Check if the descriptor belongs to interface attached to this instance. */
189 if (descriptor_type == UX_HOST_CLASS_HID_DESCRIPTOR)
190 {
191
192 /* Ensure this interface is the one we need to scan. */
193 if (current_interface == hid -> ux_host_class_hid_interface -> ux_interface_descriptor.bInterfaceNumber)
194 {
195
196 /* Obtain the length of the HID descriptor. We need to make machine
197 independent first. */
198 _ux_utility_descriptor_parse(descriptor, _ux_system_hid_descriptor_structure,
199 UX_HID_DESCRIPTOR_ENTRIES, (UCHAR *) &hid_descriptor);
200
201 /* We have found the hid descriptor. Now we should get the HID report descriptor. */
202 status = _ux_host_class_hid_report_descriptor_get(hid, hid_descriptor.wItemLength);
203
204 /* No release, the memory will be released after all interface scan done(enumeration done). */
205 device -> ux_device_packed_configuration = start_descriptor;
206
207 /* Return completion status. */
208 return(status);
209 }
210 }
211
212 /* Verify if the descriptor is still valid. */
213 if (descriptor_length > total_configuration_length)
214 {
215
216 /* Error trap. */
217 _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_DESCRIPTOR_CORRUPTED);
218
219 /* If trace is enabled, insert this event into the trace buffer. */
220 UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_DESCRIPTOR_CORRUPTED, descriptor, 0, 0, UX_TRACE_ERRORS, 0, 0)
221
222 /* Release the memory. */
223 _ux_utility_memory_free(start_descriptor);
224
225 /* Return an error. */
226 return(UX_DESCRIPTOR_CORRUPTED);
227 }
228
229 /* Jump to the next descriptor if we have not reached the end. */
230 descriptor += descriptor_length;
231
232 /* And adjust the length left to parse in the descriptor. */
233 total_configuration_length -= descriptor_length;
234 }
235 }
236
237 /* Error trap. */
238 _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_DESCRIPTOR_CORRUPTED);
239
240 /* If trace is enabled, insert this event into the trace buffer. */
241 UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_DESCRIPTOR_CORRUPTED, start_descriptor, 0, 0, UX_TRACE_ERRORS, 0, 0)
242
243 /* Free all used resources. */
244 if (device -> ux_device_packed_configuration == UX_NULL)
245 _ux_utility_memory_free(start_descriptor);
246
247 /* Return an error. */
248 return(UX_DESCRIPTOR_CORRUPTED);
249 }
250
251
