summaryrefslogtreecommitdiff
path: root/common/usbx_host_controllers/src/ux_hcd_ohci_regular_td_obtain.c
blob: 48d5d2d909bc21ae67311af95879ca4820f8420c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
/***************************************************************************
 * Copyright (c) 2024 Microsoft Corporation
 * Copyright (c) 2026-present Eclipse ThreadX contributors
 *
 * This program and the accompanying materials are made available under the
 * terms of the MIT License which is available at
 * https://opensource.org/licenses/MIT.
 *
 * SPDX-License-Identifier: MIT
 **************************************************************************/


/**************************************************************************/
/**************************************************************************/
/**                                                                       */
/** USBX Component                                                        */
/**                                                                       */
/**   OHCI Controller Driver                                              */
/**                                                                       */
/**************************************************************************/
/**************************************************************************/


/* Include necessary system files.  */

#define UX_SOURCE_CODE

#include "ux_api.h"
#include "ux_hcd_ohci.h"
#include "ux_host_stack.h"


/**************************************************************************/
/*                                                                        */
/*  FUNCTION                                               RELEASE        */
/*                                                                        */
/*    _ux_hcd_ohci_regular_td_obtain                      PORTABLE C      */
/*                                                           6.1.11       */
/*  AUTHOR                                                                */
/*                                                                        */
/*    Chaoqiong Xiao, Microsoft Corporation                               */
/*                                                                        */
/*  DESCRIPTION                                                           */
/*                                                                        */
/*     This function obtains a free TD from the regular TD list.          */
/*                                                                        */
/*  INPUT                                                                 */
/*                                                                        */
/*    hcd_ohci                              Pointer to OHCI controller    */
/*                                                                        */
/*  OUTPUT                                                                */
/*                                                                        */
/*    *UX_OHCI_TD                           Regular TD pointer            */
/*                                                                        */
/*  CALLS                                                                 */
/*                                                                        */
/*    _ux_utility_memory_set                Set memory block              */
/*    _ux_host_mutex_on                     Get protection mutex          */
/*    _ux_host_mutex_off                    Release protection mutex      */
/*                                                                        */
/*  CALLED BY                                                             */
/*                                                                        */
/*    OHCI Controller Driver                                              */
/*                                                                        */
/**************************************************************************/
UX_OHCI_TD  *_ux_hcd_ohci_regular_td_obtain(UX_HCD_OHCI *hcd_ohci)
{

UX_OHCI_TD      *td;
ULONG           td_index;


    /* Set the Mutex as this is a critical section.  */
    _ux_host_mutex_on(&_ux_system -> ux_system_mutex);

    /* Start the search from the beginning of the regular TD list.  */
    td =  hcd_ohci -> ux_hcd_ohci_td_list;

    for (td_index = 0; td_index < _ux_system_host -> ux_system_host_max_td; td_index++)
    {

        /* Check the TD status, a free TD is marked with the UNUSED flag.  */
        if (td -> ux_ohci_td_status == UX_UNUSED)
        {

            /* The TD may have been used, so we reset all fields.  */
            _ux_utility_memory_set(td, 0, sizeof(UX_OHCI_TD)); /* Use case of memset is verified. */

            /* This TD is now marked as USED.  */
            td -> ux_ohci_td_status =  UX_USED;

            /* Release the protection.  */
            _ux_host_mutex_off(&_ux_system -> ux_system_mutex);

            /* Return TD pointer - success!  */
            return(td);
        }

        /* Move to the next TD.  */
        td++;
    }

    /* There is no available TD in the TD list.  */

    /* Release protection.  */
    _ux_host_mutex_off(&_ux_system -> ux_system_mutex);

    /* Return NULL to caller.  */
    return(UX_NULL);
}