// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2008, Creative Technology Ltd. All Rights Reserved.
 *
 * @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);
        }
}