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 /** Host Stack */
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_stack.h"
29
30
31 /**************************************************************************/
32 /* */
33 /* FUNCTION RELEASE */
34 /* */
35 /* _ux_host_stack_new_device_get PORTABLE C */
36 /* 6.1.12 */
37 /* AUTHOR */
38 /* */
39 /* Chaoqiong Xiao, Microsoft Corporation */
40 /* */
41 /* DESCRIPTION */
42 /* */
43 /* This function obtains a free device container for the new device. */
44 /* */
45 /* INPUT */
46 /* */
47 /* None */
48 /* */
49 /* OUTPUT */
50 /* */
51 /* UX_DEVICE pointer */
52 /* */
53 /* CALLS */
54 /* */
55 /* _ux_utility_memory_set Set memory to a value */
56 /* */
57 /* CALLED BY */
58 /* */
59 /* USBX Components */
60 /* */
61 /* RELEASE HISTORY */
62 /* */
63 /* DATE NAME DESCRIPTION */
64 /* */
65 /* 05-19-2020 Chaoqiong Xiao Initial Version 6.0 */
66 /* 09-30-2020 Chaoqiong Xiao Modified comment(s), */
67 /* optimized based on compile */
68 /* definitions, verified */
69 /* memset and memcpy cases, */
70 /* resulting in version 6.1 */
71 /* 07-29-2022 Chaoqiong Xiao Modified comment(s), */
72 /* fixed standalone enum init, */
73 /* resulting in version 6.1.12 */
74 /* */
75 /**************************************************************************/
_ux_host_stack_new_device_get(VOID)76 UX_DEVICE *_ux_host_stack_new_device_get(VOID)
77 {
78
79 #if UX_MAX_DEVICES > 1
80 ULONG container_index;
81 #endif
82 UX_DEVICE *device;
83 #if defined(UX_HOST_STANDALONE)
84 UX_DEVICE *enum_next;
85 #endif
86
87 /* Start with the first device. */
88 device = _ux_system_host -> ux_system_host_device_array;
89
90 #if UX_MAX_DEVICES > 1
91 /* Reset the container index. */
92 container_index = 0;
93
94 /* Search the list until the end. */
95 while (container_index++ < _ux_system_host -> ux_system_host_max_devices)
96 #endif
97 {
98
99 /* Until we have found an unused entry. */
100 if (device -> ux_device_handle == UX_UNUSED)
101 {
102
103 #if defined(UX_HOST_STANDALONE)
104
105 /* Reset the entire entry except enum link. */
106 enum_next = device -> ux_device_enum_next;
107 _ux_utility_memory_set(device, 0, sizeof(UX_DEVICE)); /* Use case of memset is verified. */
108 device -> ux_device_enum_next = enum_next;
109 #else
110
111 /* Reset the entire entry. */
112 _ux_utility_memory_set(device, 0, sizeof(UX_DEVICE)); /* Use case of memset is verified. */
113 #endif
114
115 /* This entry is now used. */
116 device -> ux_device_handle = UX_USED;
117
118 /* Return the device pointer. */
119 return(device);
120 }
121 #if UX_MAX_DEVICES > 1
122
123 /* Move to the next device entry. */
124 device++;
125 #endif
126 }
127
128 /* No unused devices, return NULL. */
129 return(UX_NULL);
130 }
131
132
