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 /** Device HID Class */
19 /** */
20 /**************************************************************************/
21 /**************************************************************************/
22
23 #define UX_SOURCE_CODE
24
25
26 /* Include necessary system files. */
27
28 #include "ux_api.h"
29 #include "ux_device_class_hid.h"
30 #include "ux_device_stack.h"
31
32
33 /**************************************************************************/
34 /* */
35 /* FUNCTION RELEASE */
36 /* */
37 /* _ux_device_class_hid_descriptor_send PORTABLE C */
38 /* 6.1.8 */
39 /* AUTHOR */
40 /* */
41 /* Chaoqiong Xiao, Microsoft Corporation */
42 /* */
43 /* DESCRIPTION */
44 /* */
45 /* This function sends back the class descriptor required by the host. */
46 /* */
47 /* INPUT */
48 /* */
49 /* descriptor_type Descriptor type */
50 /* descriptor_index Index of descriptor */
51 /* host_length Length requested by host */
52 /* */
53 /* OUTPUT */
54 /* */
55 /* Completion Status */
56 /* */
57 /* CALLS */
58 /* */
59 /* (ux_slave_dcd_function) DCD dispatch function */
60 /* _ux_device_stack_transfer_request Process transfer request */
61 /* _ux_utility_memory_copy Memory copy */
62 /* */
63 /* CALLED BY */
64 /* */
65 /* Application */
66 /* Device Stack */
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 /* verified memset and memcpy */
75 /* cases, */
76 /* resulting in version 6.1 */
77 /* 08-02-2021 Chaoqiong Xiao Modified comment(s), */
78 /* fixed HID descriptor search,*/
79 /* resulting in version 6.1.8 */
80 /* */
81 /**************************************************************************/
_ux_device_class_hid_descriptor_send(UX_SLAVE_CLASS_HID * hid,ULONG descriptor_type,ULONG request_index,ULONG host_length)82 UINT _ux_device_class_hid_descriptor_send(UX_SLAVE_CLASS_HID *hid, ULONG descriptor_type,
83 ULONG request_index, ULONG host_length)
84 {
85
86 UX_SLAVE_DCD *dcd;
87 UX_SLAVE_DEVICE *device;
88 UX_SLAVE_TRANSFER *transfer_request;
89 UX_SLAVE_ENDPOINT *endpoint;
90 UCHAR * device_framework;
91 UCHAR * device_framework_end;
92 ULONG descriptor_length;
93 UINT status = UX_ERROR;
94 ULONG length;
95 UCHAR interface_number = 0xFF;
96
97 UX_PARAMETER_NOT_USED(request_index);
98
99 /* If trace is enabled, insert this event into the trace buffer. */
100 UX_TRACE_IN_LINE_INSERT(UX_TRACE_DEVICE_CLASS_HID_DESCRIPTOR_SEND, hid, descriptor_type, request_index, 0, UX_TRACE_DEVICE_CLASS_EVENTS, 0, 0)
101
102 /* Get the pointer to the DCD. */
103 dcd = &_ux_system_slave -> ux_system_slave_dcd;
104
105 /* Get the pointer to the device. */
106 device = &_ux_system_slave -> ux_system_slave_device;
107
108 /* Get the control endpoint associated with the device. */
109 endpoint = &device -> ux_slave_device_control_endpoint;
110
111 /* Get the pointer to the transfer request associated with the endpoint. */
112 transfer_request = &endpoint -> ux_slave_endpoint_transfer_request;
113
114 /* Set the direction to OUT. */
115 transfer_request -> ux_slave_transfer_request_phase = UX_TRANSFER_PHASE_DATA_OUT;
116
117 /* Shift the descriptor type in the low byte field. */
118 descriptor_type = (UCHAR) ((descriptor_type >> 8) & 0xff);
119
120 /* What type of descriptor do we need to return? */
121 switch (descriptor_type)
122 {
123
124 case UX_DEVICE_CLASS_HID_DESCRIPTOR_HID:
125
126 /* We should have a HID descriptor as part of the config descriptor. */
127 device_framework = _ux_system_slave -> ux_system_slave_device_framework;
128 device_framework_end = device_framework + _ux_system_slave -> ux_system_slave_device_framework_length;
129
130 /* Parse the device framework and locate the HID descriptor.
131 There is only one HID descriptor. */
132 while (device_framework < device_framework_end)
133 {
134
135 /* Get the type of the current descriptor. */
136 descriptor_type = *(device_framework + 1);
137
138 /* And its length. */
139 descriptor_length = (ULONG) *device_framework;
140
141 /* Save interface number for later check. */
142 if (descriptor_type == UX_INTERFACE_DESCRIPTOR_ITEM)
143 interface_number = *(device_framework + 2);
144
145 /* Check if this is a HID report descriptor. */
146 if ((descriptor_type == UX_DEVICE_CLASS_HID_DESCRIPTOR_HID) &&
147 (interface_number == (UCHAR)request_index))
148 {
149
150 /* Ensure the host does not demand a length beyond our descriptor (Windows does that)
151 and do not return more than what is allowed. */
152 if (descriptor_length < host_length)
153 length = descriptor_length;
154 else
155 length = host_length;
156
157 /* Check buffer length, since descriptor length may exceed buffer... */
158 if (length > UX_SLAVE_REQUEST_CONTROL_MAX_LENGTH)
159 {
160
161 /* Error trap. */
162 _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_MEMORY_INSUFFICIENT);
163
164 /* If trace is enabled, insert this event into the trace buffer. */
165 UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_MEMORY_INSUFFICIENT, hid, 0, 0, UX_TRACE_ERRORS, 0, 0)
166
167 /* Stall the endpoint. */
168 status = dcd -> ux_slave_dcd_function(dcd, UX_DCD_STALL_ENDPOINT, endpoint);
169 break;
170 }
171
172 /* Copy the device descriptor into the transfer request memory. */
173 _ux_utility_memory_copy(transfer_request -> ux_slave_transfer_request_data_pointer,
174 device_framework, length); /* Use case of memcpy is verified. */
175
176 /* We can return the configuration descriptor. */
177 status = _ux_device_stack_transfer_request(transfer_request, length, host_length);
178 break;
179
180 }
181
182 /* Point to the next descriptor. */
183 device_framework += descriptor_length;
184 }
185
186 /* Stall the endpoint if not found or corrupt. */
187 if (device_framework >= device_framework_end)
188 status = dcd -> ux_slave_dcd_function(dcd, UX_DCD_STALL_ENDPOINT, endpoint);
189
190 break;
191
192 case UX_DEVICE_CLASS_HID_DESCRIPTOR_REPORT:
193
194 /* Get the length of entire configuration descriptor. */
195 descriptor_length = hid -> ux_device_class_hid_report_length;
196
197 /* Ensure the host does not demand a length beyond our descriptor (Windows does that)
198 and do not return more than what is allowed. */
199 if (descriptor_length < host_length)
200 length = descriptor_length;
201 else
202 length = host_length;
203
204 /* Check buffer length, since total descriptors length may exceed buffer... */
205 if (length > UX_SLAVE_REQUEST_CONTROL_MAX_LENGTH)
206 {
207
208 /* Error trap. */
209 _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_MEMORY_INSUFFICIENT);
210
211 /* If trace is enabled, insert this event into the trace buffer. */
212 UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_MEMORY_INSUFFICIENT, hid, 0, 0, UX_TRACE_ERRORS, 0, 0)
213
214 /* Stall the endpoint. */
215 status = dcd -> ux_slave_dcd_function(dcd, UX_DCD_STALL_ENDPOINT, endpoint);
216 break;
217 }
218
219 /* Copy the device descriptor into the transfer request memory. */
220 _ux_utility_memory_copy(transfer_request -> ux_slave_transfer_request_data_pointer,
221 hid -> ux_device_class_hid_report_address, length); /* Use case of memcpy is verified. */
222
223 /* We can return the report descriptor. */
224 status = _ux_device_stack_transfer_request(transfer_request, length, host_length);
225 break;
226
227 case UX_DEVICE_CLASS_HID_DESCRIPTOR_PHYSICAL:
228
229 /* Not treated for now. Fall through and Stall endpoint. */
230
231 default:
232
233 /* Stall the endpoint. */
234 dcd -> ux_slave_dcd_function(dcd, UX_DCD_STALL_ENDPOINT, endpoint);
235 return(UX_ERROR);
236 }
237
238 /* Return the status to the caller. */
239 return(status);
240 }
241
242
