drivers/staging/meilhaus/medlist.c

   1 /**
   2  * @file me_dlist.c
   3  *
   4  * @brief Implements the device list class.
   5  * @note Copyright (C) 2007 Meilhaus Electronic GmbH (support@meilhaus.de)
   6  * @author Guenter Gebhardt
   7  */
   8
   9 /*
  10  * Copyright (C) 2007 Meilhaus Electronic GmbH (support@meilhaus.de)
  11  *
  12  * This file is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  25  */
  26
  27 #include "meerror.h"
  28 #include "medefines.h"
  29
  30 #include "medlist.h"
  31 #include "medebug.h"
  32
  33 int me_dlist_query_number_devices(struct me_dlist *dlist, int *number)
  34 {
  35         PDEBUG_LOCKS("called.\n");
  36         *number = dlist->n;
  37         return ME_ERRNO_SUCCESS;
  38 }
  39
  40 unsigned int me_dlist_get_number_devices(struct me_dlist *dlist)
  41 {
  42         PDEBUG_LOCKS("called.\n");
  43         return dlist->n;
  44 }
  45
  46 me_device_t *me_dlist_get_device(struct me_dlist * dlist, unsigned int index)
  47 {
  48
  49         struct list_head *pos;
  50         me_device_t *device = NULL;
  51         unsigned int i = 0;
  52
  53         PDEBUG_LOCKS("called.\n");
  54
  55         if (index >= dlist->n) {
  56                 PERROR("Index out of range.\n");
  57                 return NULL;
  58         }
  59
  60         list_for_each(pos, &dlist->head) {
  61                 if (i == index) {
  62                         device = list_entry(pos, me_device_t, list);
  63                         break;
  64                 }
  65
  66                 ++i;
  67         }
  68
  69         return device;
  70 }
  71
  72 void me_dlist_add_device_tail(struct me_dlist *dlist, me_device_t *device)
  73 {
  74         PDEBUG_LOCKS("called.\n");
  75
  76         list_add_tail(&device->list, &dlist->head);
  77         ++dlist->n;
  78 }
  79
  80 me_device_t *me_dlist_del_device_tail(struct me_dlist *dlist)
  81 {
  82
  83         struct list_head *last;
  84         me_device_t *device;
  85
  86         PDEBUG_LOCKS("called.\n");
  87
  88         if (list_empty(&dlist->head))
  89                 return NULL;
  90
  91         last = dlist->head.prev;
  92
  93         device = list_entry(last, me_device_t, list);
  94
  95         list_del(last);
  96
  97         --dlist->n;
  98
  99         return device;
 100 }
 101
 102 int me_dlist_init(me_dlist_t *dlist)
 103 {
 104         PDEBUG_LOCKS("called.\n");
 105
 106         INIT_LIST_HEAD(&dlist->head);
 107         dlist->n = 0;
 108         return 0;
 109 }
 110
 111 void me_dlist_deinit(me_dlist_t *dlist)
 112 {
 113
 114         struct list_head *s;
 115         me_device_t *device;
 116
 117         PDEBUG_LOCKS("called.\n");
 118
 119         while (!list_empty(&dlist->head)) {
 120                 s = dlist->head.next;
 121                 list_del(s);
 122                 device = list_entry(s, me_device_t, list);
 123                 device->me_device_destructor(device);
 124         }
 125
 126         dlist->n = 0;
 127 }