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 /** Host Stack */
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_stack.h"
30
31
32 /**************************************************************************/
33 /* */
34 /* FUNCTION RELEASE */
35 /* */
36 /* _ux_host_stack_enum_thread_entry PORTABLE C */
37 /* 6.1.10 */
38 /* AUTHOR */
39 /* */
40 /* Chaoqiong Xiao, Microsoft Corporation */
41 /* */
42 /* DESCRIPTION */
43 /* */
44 /* This file contains the enum thread for USBX. It is in charge of */
45 /* the topology changes either from device insertion\extraction on */
46 /* the root hub or on a regular hub. */
47 /* */
48 /* This thread ensures we never have more that 2 instances trying to */
49 /* perform a change to the topology (mostly enumeration) for fear that */
50 /* more than one device could answer to address 0. */
51 /* */
52 /* This function is the entry point of the topology thread. It waits */
53 /* until one of the HCDs or a hub sets the semaphore to indicate */
54 /* there has been a change in the USB topology which could be either */
55 /* a insertion or extraction or eventually a hub downstream port */
56 /* signal. */
57 /* */
58 /* This is for RTOS mode. */
59 /* */
60 /* INPUT */
61 /* */
62 /* input Not used input */
63 /* */
64 /* OUTPUT */
65 /* */
66 /* None */
67 /* */
68 /* CALLS */
69 /* */
70 /* _ux_host_stack_rh_change_process Root hub processing */
71 /* _ux_utility_semaphore_get Get signal semaphore */
72 /* (ux_system_host_enum_hub_function) HUB enum processing function */
73 /* */
74 /* CALLED BY */
75 /* */
76 /* ThreadX */
77 /* */
78 /* RELEASE HISTORY */
79 /* */
80 /* DATE NAME DESCRIPTION */
81 /* */
82 /* 05-19-2020 Chaoqiong Xiao Initial Version 6.0 */
83 /* 09-30-2020 Chaoqiong Xiao Modified comment(s), */
84 /* optimized based on compile */
85 /* definitions, */
86 /* resulting in version 6.1 */
87 /* 01-31-2022 Chaoqiong Xiao Modified comment(s), */
88 /* refined macros names, */
89 /* resulting in version 6.1.10 */
90 /* */
91 /**************************************************************************/
_ux_host_stack_enum_thread_entry(ULONG input)92 VOID _ux_host_stack_enum_thread_entry(ULONG input)
93 {
94
95 UX_PARAMETER_NOT_USED(input);
96
97 /* Loop forever waiting for changes signaled through the semaphore. */
98 while (1)
99 {
100
101 /* Wait for the semaphore to be put by the root hub or a regular hub. */
102 _ux_host_semaphore_get_norc(&_ux_system_host -> ux_system_host_enum_semaphore, UX_WAIT_FOREVER);
103
104 #if UX_MAX_DEVICES > 1
105 /* We try the hub first. For this we look into the USBX project
106 structure to see if there is at least one hub. */
107 if (_ux_system_host -> ux_system_host_enum_hub_function != UX_NULL)
108 {
109
110 /* Yes, there is a HUB function, call it! */
111 _ux_system_host -> ux_system_host_enum_hub_function();
112 }
113 #endif
114
115 /* The signal may be also coming from the root hub, call the root hub handler. */
116 _ux_host_stack_rh_change_process();
117 }
118 }
119
120
