/**
   * Copyright (C) 2008, Creative Technology Ltd. All Rights Reserved.
   *
   * This source file is released under GPL v2 license (no other versions).
   * See the COPYING file included in the main directory of this source
   * distribution for the license terms and conditions.
   *
   * @File	ctimap.c
   *
   * @Brief
   * This file contains the implementation of generic input mapper operations
   * for input mapper management.
   *
   * @Author	Liu Chun
   * @Date 	May 23 2008
   *
   */
  
  #include "ctimap.h"
  #include <linux/slab.h>
  
  int input_mapper_add(struct list_head *mappers, struct imapper *entry,
  		     int (*map_op)(void *, struct imapper *), void *data)
  {
  	struct list_head *pos, *pre, *head;
  	struct imapper *pre_ent, *pos_ent;
  
  	head = mappers;
  
  	if (list_empty(head)) {
  		entry->next = entry->addr;
  		map_op(data, entry);
  		list_add(&entry->list, head);
  		return 0;
  	}
  
  	list_for_each(pos, head) {
  		pos_ent = list_entry(pos, struct imapper, list);
  		if (pos_ent->slot > entry->slot) {
  			/* found a position in list */
  			break;
  		}
  	}
  
  	if (pos != head) {
  		pre = pos->prev;
  		if (pre == head)
  			pre = head->prev;
  
  		__list_add(&entry->list, pos->prev, pos);
  	} else {
  		pre = head->prev;
  		pos = head->next;
  		list_add_tail(&entry->list, head);
  	}
  
  	pre_ent = list_entry(pre, struct imapper, list);
  	pos_ent = list_entry(pos, struct imapper, list);
  
  	entry->next = pos_ent->addr;
  	map_op(data, entry);
  	pre_ent->next = entry->addr;
  	map_op(data, pre_ent);
  
  	return 0;
  }
  
  int input_mapper_delete(struct list_head *mappers, struct imapper *entry,
  		     int (*map_op)(void *, struct imapper *), void *data)
  {
  	struct list_head *next, *pre, *head;
  	struct imapper *pre_ent, *next_ent;
  
  	head = mappers;
  
  	if (list_empty(head))
  		return 0;
  
  	pre = (entry->list.prev == head) ? head->prev : entry->list.prev;
  	next = (entry->list.next == head) ? head->next : entry->list.next;
  
  	if (pre == &entry->list) {
  		/* entry is the only one node in mappers list */
  		entry->next = entry->addr = entry->user = entry->slot = 0;
  		map_op(data, entry);
  		list_del(&entry->list);
  		return 0;
  	}
  
  	pre_ent = list_entry(pre, struct imapper, list);
  	next_ent = list_entry(next, struct imapper, list);
  
  	pre_ent->next = next_ent->addr;
  	map_op(data, pre_ent);
  	list_del(&entry->list);
  
  	return 0;
  }
  
  void free_input_mapper_list(struct list_head *head)
  {

  	struct imapper *entry;
  	struct list_head *pos;

  
  	while (!list_empty(head)) {
  		pos = head->next;
  		list_del(pos);
  		entry = list_entry(pos, struct imapper, list);
  		kfree(entry);
  	}
  }