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 Remote Control 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_class_hid_remote_control.h"
31 #include "ux_host_stack.h"
32
33
34 /**************************************************************************/
35 /* */
36 /* FUNCTION RELEASE */
37 /* */
38 /* _ux_host_class_hid_remote_control_callback PORTABLE C */
39 /* 6.1 */
40 /* AUTHOR */
41 /* */
42 /* Chaoqiong Xiao, Microsoft Corporation */
43 /* */
44 /* DESCRIPTION */
45 /* */
46 /* This function is the callback mechanism for a report registration. */
47 /* */
48 /* INPUT */
49 /* */
50 /* callback Pointer to callback */
51 /* */
52 /* OUTPUT */
53 /* */
54 /* None */
55 /* */
56 /* CALLS */
57 /* */
58 /* None */
59 /* */
60 /* CALLED BY */
61 /* */
62 /* HID Remote Control Class */
63 /* */
64 /* RELEASE HISTORY */
65 /* */
66 /* DATE NAME DESCRIPTION */
67 /* */
68 /* 05-19-2020 Chaoqiong Xiao Initial Version 6.0 */
69 /* 09-30-2020 Chaoqiong Xiao Modified comment(s), */
70 /* resulting in version 6.1 */
71 /* */
72 /**************************************************************************/
_ux_host_class_hid_remote_control_callback(UX_HOST_CLASS_HID_REPORT_CALLBACK * callback)73 VOID _ux_host_class_hid_remote_control_callback(UX_HOST_CLASS_HID_REPORT_CALLBACK *callback)
74 {
75
76 UX_HOST_CLASS_HID_CLIENT *hid_client;
77 UX_HOST_CLASS_HID_REMOTE_CONTROL *remote_control_instance;
78 ULONG *array_head;
79 ULONG *array_tail;
80 ULONG *array_end;
81 ULONG *array_start;
82 ULONG *array_head_next;
83
84
85 /* Get the HID client instance that issued the callback. */
86 hid_client = callback -> ux_host_class_hid_report_callback_client;
87
88 /* Get the remote control local instance. */
89 remote_control_instance = (UX_HOST_CLASS_HID_REMOTE_CONTROL *) hid_client -> ux_host_class_hid_client_local_instance;
90
91 /* Load the remote control usage/value array info. */
92 array_start = remote_control_instance -> ux_host_class_hid_remote_control_usage_array;
93 array_end = array_start + UX_HOST_CLASS_HID_REMOTE_CONTROL_USAGE_ARRAY_LENGTH;
94 array_head = remote_control_instance -> ux_host_class_hid_remote_control_usage_array_head;
95 array_tail = remote_control_instance -> ux_host_class_hid_remote_control_usage_array_tail;
96
97 /* We have a single usage/value. We have to store it into the array. If the array overflows,
98 there is no mechanism for flow control here so we ignore the usage/value until the
99 applications makes more room in the array. */
100
101 /* Get position where next head will be. */
102 array_head_next = array_head + 2;
103
104 /* The head always points to where we will insert the next element. This
105 is the reason for the wrap. */
106 if (array_head_next == array_end)
107 array_head_next = array_start;
108
109 /* Do we have enough space to store the new usage? */
110 if (array_head_next != array_tail)
111 {
112
113 /* Yes, we have some space. */
114 *array_head = callback -> ux_host_class_hid_report_callback_usage;
115 *(array_head + 1) = callback -> ux_host_class_hid_report_callback_value;
116
117 /* Now update the array head. */
118 remote_control_instance -> ux_host_class_hid_remote_control_usage_array_head = array_head_next;
119 }
120 else
121 {
122
123 /* If trace is enabled, insert this event into the trace buffer. */
124 UX_TRACE_IN_LINE_INSERT(UX_TRACE_HOST_CLASS_HID_REMOTE_CONTROL_CALLBACK, hid_client, remote_control_instance, 0, 0, UX_TRACE_HOST_CLASS_EVENTS, 0, 0)
125
126 /* Notify application. */
127 _ux_system_error_handler(UX_SYSTEM_LEVEL_THREAD, UX_SYSTEM_CONTEXT_CLASS, UX_BUFFER_OVERFLOW);
128 }
129
130 /* Return to caller. */
131 return;
132 }
133
134
