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 /** HID 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_hid.h"
30 #include "ux_host_stack.h"
31
32
33 /**************************************************************************/
34 /* */
35 /* FUNCTION RELEASE */
36 /* */
37 /* _ux_host_class_hid_descriptor_parse PORTABLE C */
38 /* 6.1.12 */
39 /* AUTHOR */
40 /* */
41 /* Chaoqiong Xiao, Microsoft Corporation */
42 /* */
43 /* DESCRIPTION */
44 /* */
45 /* This function obtains the HID descriptor and parses it. */
46 /* */
47 /* INPUT */
48 /* */
49 /* hid Pointer to HID class */
50 /* */
51 /* OUTPUT */
52 /* */
53 /* Completion Status */
54 /* */
55 /* CALLS */
56 /* */
57 /* _ux_host_class_hid_report_descriptor_get */
58 /* Get HID report descriptor */
59 /* _ux_host_stack_transfer_request Process transfer request */
60 /* _ux_utility_descriptor_parse Parse descriptor */
61 /* _ux_utility_memory_allocate Allocate memory block */
62 /* _ux_utility_memory_free Release memory block */
63 /* */
64 /* CALLED BY */
65 /* */
66 /* HID Class */
67 /* */
68 /* RELEASE HISTORY */
69 /* */
70 /* DATE NAME DESCRIPTION */
71 /* */
72 /* 05-19-2020 Chaoqiong Xiao Initial Version 6.0 */
73 /* 09-30-2020 Chaoqiong Xiao Modified comment(s), */
74 /* resulting in version 6.1 */
75 /* 07-29-2022 Chaoqiong Xiao Modified comment(s), */
76 /* used shared device config */
77 /* descriptor for enum scan, */
78 /* resulting in version 6.1.12 */
79 /* */
80 /**************************************************************************/
_ux_host_class_hid_descriptor_parse(UX_HOST_CLASS_HID * hid)81 UINT _ux_host_class_hid_descriptor_parse(UX_HOST_CLASS_HID *hid)
82 {
83
84 UX_DEVICE *device;
85 UX_CONFIGURATION *configuration;
86 UCHAR *descriptor;
87 UCHAR *start_descriptor;
88 UX_ENDPOINT *control_endpoint;
89 UX_TRANSFER *transfer_request;
90 UX_HID_DESCRIPTOR hid_descriptor;
91 UX_INTERFACE_DESCRIPTOR interface_descriptor;
92 UINT status;
93 ULONG total_configuration_length;
94 UINT descriptor_length;
95 UINT descriptor_type;
96 ULONG current_interface;
97
98 /* Get device, current configuration. */
99 device = hid -> ux_host_class_hid_device;
100 configuration = device -> ux_device_current_configuration;
101 total_configuration_length = configuration -> ux_configuration_descriptor.wTotalLength;
102
103 /* Check if descriptor is previously saved. */
104 if (device -> ux_device_packed_configuration != UX_NULL)
105 {
106 start_descriptor = device -> ux_device_packed_configuration;
107 descriptor = start_descriptor;
108 status = UX_SUCCESS;
109 }
110 else
111 {
112
113 /* We need to get the default control endpoint transfer request pointer. */
114 control_endpoint = &device -> ux_device_control_endpoint;
115 transfer_request = &control_endpoint -> ux_endpoint_transfer_request;
116
117 /* Need to allocate memory for the descriptor. Since we do not know the size of the
118 descriptor, we first read the first bytes. */
119 descriptor = _ux_utility_memory_allocate(UX_SAFE_ALIGN, UX_CACHE_SAFE_MEMORY, total_configuration_length);
120 if (descriptor == UX_NULL)
121 return(UX_MEMORY_INSUFFICIENT);
122
123 /* Memorize the descriptor start address. */
124 start_descriptor = descriptor;
125
126 /* Create a transfer request for the GET_DESCRIPTOR request. */
127 transfer_request -> ux_transfer_request_data_pointer = descriptor;
128 transfer_request -> ux_transfer_request_requested_length = total_configuration_length;
129 transfer_request -> ux_transfer_request_function = UX_GET_DESCRIPTOR;
130 transfer_request -> ux_transfer_request_type = UX_REQUEST_IN | UX_REQUEST_TYPE_STANDARD | UX_REQUEST_TARGET_DEVICE;
131 transfer_request -> ux_transfer_request_value = UX_CONFIGURATION_DESCRIPTOR_ITEM << 8;
132 transfer_request -> ux_transfer_request_index = 0;
133
134 /* Send request to HCD layer. */
135 status = _ux_host_stack_transfer_request(transfer_request);
136
137 /* Check descriptor length. */
138 if (transfer_request -> ux_transfer_request_actual_length != total_configuration_length)
139 status = UX_DESCRIPTOR_CORRUPTED;
140 }
141
142 /* Reset the current interface to keep compiler warnings happy. */
143 current_interface = 0;
144
145 /* Check for correct transfer and entire descriptor returned. */
146 if (status == UX_SUCCESS)
147 {
148
149 /* The HID descriptor is embedded within the configuration descriptor. We parse the
150 entire descriptor to locate the HID portion. */
151 while (total_configuration_length)
152 {
153
154 /* Gather the length and type of the descriptor. */
155 descriptor_length = *descriptor;
156 descriptor_type = *(descriptor + 1);
157
158 /* Make sure this descriptor has at least the minimum length. */
159 if (descriptor_length < 3)
160 {
161
162 /* Error trap. */
163 _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_DESCRIPTOR_CORRUPTED);
164
165 /* If trace is enabled, insert this event into the trace buffer. */
166 UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_DESCRIPTOR_CORRUPTED, descriptor, 0, 0, UX_TRACE_ERRORS, 0, 0)
167
168 /* Error, release the memory and return an error. */
169 _ux_utility_memory_free(start_descriptor);
170
171 return(UX_DESCRIPTOR_CORRUPTED);
172 }
173
174 /* Check the type for an interface descriptor. */
175 if (descriptor_type == UX_INTERFACE_DESCRIPTOR_ITEM)
176 {
177
178 /* Parse the interface descriptor and make it machine independent. */
179 _ux_utility_descriptor_parse(descriptor,
180 _ux_system_interface_descriptor_structure,
181 UX_INTERFACE_DESCRIPTOR_ENTRIES,
182 (UCHAR *) &interface_descriptor);
183
184 /* Memorize the interface we are scanning. */
185 current_interface = interface_descriptor.bInterfaceNumber;
186 }
187
188 /* Check the type for an interface descriptor. */
189 /* Check if the descriptor belongs to interface attached to this instance. */
190 if (descriptor_type == UX_HOST_CLASS_HID_DESCRIPTOR)
191 {
192
193 /* Ensure this interface is the one we need to scan. */
194 if (current_interface == hid -> ux_host_class_hid_interface -> ux_interface_descriptor.bInterfaceNumber)
195 {
196
197 /* Obtain the length of the HID descriptor. We need to make machine
198 independent first. */
199 _ux_utility_descriptor_parse(descriptor, _ux_system_hid_descriptor_structure,
200 UX_HID_DESCRIPTOR_ENTRIES, (UCHAR *) &hid_descriptor);
201
202 /* We have found the hid descriptor. Now we should get the HID report descriptor. */
203 status = _ux_host_class_hid_report_descriptor_get(hid, hid_descriptor.wItemLength);
204
205 /* No release, the memory will be released after all interface scan done(enumeration done). */
206 device -> ux_device_packed_configuration = start_descriptor;
207
208 /* Return completion status. */
209 return(status);
210 }
211 }
212
213 /* Verify if the descriptor is still valid. */
214 if (descriptor_length > total_configuration_length)
215 {
216
217 /* Error trap. */
218 _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_DESCRIPTOR_CORRUPTED);
219
220 /* If trace is enabled, insert this event into the trace buffer. */
221 UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_DESCRIPTOR_CORRUPTED, descriptor, 0, 0, UX_TRACE_ERRORS, 0, 0)
222
223 /* Release the memory. */
224 _ux_utility_memory_free(start_descriptor);
225
226 /* Return an error. */
227 return(UX_DESCRIPTOR_CORRUPTED);
228 }
229
230 /* Jump to the next descriptor if we have not reached the end. */
231 descriptor += descriptor_length;
232
233 /* And adjust the length left to parse in the descriptor. */
234 total_configuration_length -= descriptor_length;
235 }
236 }
237
238 /* Error trap. */
239 _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_DESCRIPTOR_CORRUPTED);
240
241 /* If trace is enabled, insert this event into the trace buffer. */
242 UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_DESCRIPTOR_CORRUPTED, start_descriptor, 0, 0, UX_TRACE_ERRORS, 0, 0)
243
244 /* Free all used resources. */
245 if (device -> ux_device_packed_configuration == UX_NULL)
246 _ux_utility_memory_free(start_descriptor);
247
248 /* Return an error. */
249 return(UX_DESCRIPTOR_CORRUPTED);
250 }
251
252
