LXR linux/sound/pci/ctxfi/ctimap.c

   1/**
   2 * Copyright (C) 2008, Creative Technology Ltd. All Rights Reserved.
   3 *
   4 * This source file is released under GPL v2 license (no other versions).
   5 * See the COPYING file included in the main directory of this source
   6 * distribution for the license terms and conditions.
   7 *
   8 * @File        ctimap.c
   9 *
  10 * @Brief
  11 * This file contains the implementation of generic input mapper operations
  12 * for input mapper management.
  13 *
  14 * @Author      Liu Chun
  15 * @Date        May 23 2008
  16 *
  17 */
  18
  19#include "ctimap.h"
  20#include <linux/slab.h>
  21
  22int input_mapper_add(struct list_head *mappers, struct imapper *entry,
  23                     int (*map_op)(void *, struct imapper *), void *data)
  24{
  25        struct list_head *pos, *pre, *head;
  26        struct imapper *pre_ent, *pos_ent;
  27
  28        head = mappers;
  29
  30        if (list_empty(head)) {
  31                entry->next = entry->addr;
  32                map_op(data, entry);
  33                list_add(&entry->list, head);
  34                return 0;
  35        }
  36
  37        list_for_each(pos, head) {
  38                pos_ent = list_entry(pos, struct imapper, list);
  39                if (pos_ent->slot > entry->slot) {
  40                        /* found a position in list */
  41                        break;
  42                }
  43        }
  44
  45        if (pos != head) {
  46                pre = pos->prev;
  47                if (pre == head)
  48                        pre = head->prev;
  49
  50                __list_add(&entry->list, pos->prev, pos);
  51        } else {
  52                pre = head->prev;
  53                pos = head->next;
  54                list_add_tail(&entry->list, head);
  55        }
  56
  57        pre_ent = list_entry(pre, struct imapper, list);
  58        pos_ent = list_entry(pos, struct imapper, list);
  59
  60        entry->next = pos_ent->addr;
  61        map_op(data, entry);
  62        pre_ent->next = entry->addr;
  63        map_op(data, pre_ent);
  64
  65        return 0;
  66}
  67
  68int input_mapper_delete(struct list_head *mappers, struct imapper *entry,
  69                     int (*map_op)(void *, struct imapper *), void *data)
  70{
  71        struct list_head *next, *pre, *head;
  72        struct imapper *pre_ent, *next_ent;
  73
  74        head = mappers;
  75
  76        if (list_empty(head))
  77                return 0;
  78
  79        pre = (entry->list.prev == head) ? head->prev : entry->list.prev;
  80        next = (entry->list.next == head) ? head->next : entry->list.next;
  81
  82        if (pre == &entry->list) {
  83                /* entry is the only one node in mappers list */
  84                entry->next = entry->addr = entry->user = entry->slot = 0;
  85                map_op(data, entry);
  86                list_del(&entry->list);
  87                return 0;
  88        }
  89
  90        pre_ent = list_entry(pre, struct imapper, list);
  91        next_ent = list_entry(next, struct imapper, list);
  92
  93        pre_ent->next = next_ent->addr;
  94        map_op(data, pre_ent);
  95        list_del(&entry->list);
  96
  97        return 0;
  98}
  99
 100void free_input_mapper_list(struct list_head *head)
 101{
 102        struct imapper *entry;
 103        struct list_head *pos;
 104
 105        while (!list_empty(head)) {
 106                pos = head->next;
 107                list_del(pos);
 108                entry = list_entry(pos, struct imapper, list);
 109                kfree(entry);
 110        }
 111}
 112
 113