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_keyboard.h"
31 #include "ux_host_stack.h"
32
33
34 /**************************************************************************/
35 /* */
36 /* FUNCTION RELEASE */
37 /* */
38 /* _ux_host_class_hid_keyboard_key_get PORTABLE C */
39 /* 6.1 */
40 /* AUTHOR */
41 /* */
42 /* Chaoqiong Xiao, Microsoft Corporation */
43 /* */
44 /* DESCRIPTION */
45 /* */
46 /* This function reads the key and keyboard state from the */
47 /* round-robin buffer. */
48 /* */
49 /* INPUT */
50 /* */
51 /* keyboard_instance Pointer to remote control */
52 /* keyboard key Pointer to keyboard key */
53 /* keyboard state Pointer to keyboard state */
54 /* */
55 /* OUTPUT */
56 /* */
57 /* Completion Status */
58 /* */
59 /* CALLS */
60 /* */
61 /* _ux_host_stack_class_instance_verify Verify instance */
62 /* */
63 /* CALLED BY */
64 /* */
65 /* User application */
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 /* */
75 /**************************************************************************/
_ux_host_class_hid_keyboard_key_get(UX_HOST_CLASS_HID_KEYBOARD * keyboard_instance,ULONG * keyboard_key,ULONG * keyboard_state)76 UINT _ux_host_class_hid_keyboard_key_get(UX_HOST_CLASS_HID_KEYBOARD *keyboard_instance,
77 ULONG *keyboard_key, ULONG *keyboard_state)
78 {
79
80 ULONG *array_head;
81 ULONG *array_tail;
82 ULONG *array_end;
83 ULONG *array_start;
84 UX_HOST_CLASS_HID *hid;
85
86 /* Get the HID class associated with the HID client. */
87 hid = keyboard_instance -> ux_host_class_hid_keyboard_hid;
88
89 /* Ensure the instance is valid. */
90 if (_ux_host_stack_class_instance_verify(_ux_system_host_class_hid_name, (VOID *) hid) != UX_SUCCESS)
91 {
92
93 /* If trace is enabled, insert this event into the trace buffer. */
94 UX_TRACE_IN_LINE_INSERT(UX_TRACE_ERROR, UX_HOST_CLASS_INSTANCE_UNKNOWN, hid, 0, 0, UX_TRACE_ERRORS, 0, 0)
95
96 return(UX_HOST_CLASS_INSTANCE_UNKNOWN);
97 }
98
99 /* Load the keyboard key and state from the usage array . */
100 array_start = keyboard_instance -> ux_host_class_hid_keyboard_usage_array;
101 array_end = array_start + UX_HOST_CLASS_HID_KEYBOARD_USAGE_ARRAY_LENGTH;
102 array_head = keyboard_instance -> ux_host_class_hid_keyboard_usage_array_head;
103 array_tail = keyboard_instance -> ux_host_class_hid_keyboard_usage_array_tail;
104
105 /* We want to extract a usage/value from the circular queue of the keyboard instance. */
106 if (array_tail == array_head)
107 return(UX_ERROR);
108
109 /* Get the usage/value from the current tail. */
110 *keyboard_key = *array_tail;
111 *keyboard_state = *(array_tail + 1);
112
113 /* Now we need to update the tail value. Are we at the end of the array? */
114 if ((array_tail+2) >= array_end)
115 array_tail = array_start;
116 else
117 array_tail+=2;
118
119 /* Set the tail pointer. */
120 keyboard_instance -> ux_host_class_hid_keyboard_usage_array_tail = array_tail;
121
122 /* The status will tell the application there is something valid in the key/state. */
123 return(UX_SUCCESS);
124 }
125
126
