sound/pci/ctxfi/ctimap.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2008, Creative Technology Ltd. All Rights Reserved.
   4  *
   5  * @File        ctimap.c
   6  *
   7  * @Brief
   8  * This file contains the implementation of generic input mapper operations
   9  * for input mapper management.
  10  *
  11  * @Author      Liu Chun
  12  * @Date        May 23 2008
  13  */
  14
  15 #include "ctimap.h"
  16 #include <linux/slab.h>
  17
  18 int input_mapper_add(struct list_head *mappers, struct imapper *entry,
  19                      int (*map_op)(void *, struct imapper *), void *data)
  20 {
  21         struct list_head *pos, *pre, *head;
  22         struct imapper *pre_ent, *pos_ent;
  23
  24         head = mappers;
  25
  26         if (list_empty(head)) {
  27                 entry->next = entry->addr;
  28                 map_op(data, entry);
  29                 list_add(&entry->list, head);
  30                 return 0;
  31         }
  32
  33         list_for_each(pos, head) {
  34                 pos_ent = list_entry(pos, struct imapper, list);
  35                 if (pos_ent->slot > entry->slot) {
  36                         /* found a position in list */
  37                         break;
  38                 }
  39         }
  40
  41         if (pos != head) {
  42                 pre = pos->prev;
  43                 if (pre == head)
  44                         pre = head->prev;
  45
  46                 __list_add(&entry->list, pos->prev, pos);
  47         } else {
  48                 pre = head->prev;
  49                 pos = head->next;
  50                 list_add_tail(&entry->list, head);
  51         }
  52
  53         pre_ent = list_entry(pre, struct imapper, list);
  54         pos_ent = list_entry(pos, struct imapper, list);
  55
  56         entry->next = pos_ent->addr;
  57         map_op(data, entry);
  58         pre_ent->next = entry->addr;
  59         map_op(data, pre_ent);
  60
  61         return 0;
  62 }
  63
  64 int input_mapper_delete(struct list_head *mappers, struct imapper *entry,
  65                      int (*map_op)(void *, struct imapper *), void *data)
  66 {
  67         struct list_head *next, *pre, *head;
  68         struct imapper *pre_ent, *next_ent;
  69
  70         head = mappers;
  71
  72         if (list_empty(head))
  73                 return 0;
  74
  75         pre = (entry->list.prev == head) ? head->prev : entry->list.prev;
  76         next = (entry->list.next == head) ? head->next : entry->list.next;
  77
  78         if (pre == &entry->list) {
  79                 /* entry is the only one node in mappers list */
  80                 entry->next = entry->addr = entry->user = entry->slot = 0;
  81                 map_op(data, entry);
  82                 list_del(&entry->list);
  83                 return 0;
  84         }
  85
  86         pre_ent = list_entry(pre, struct imapper, list);
  87         next_ent = list_entry(next, struct imapper, list);
  88
  89         pre_ent->next = next_ent->addr;
  90         map_op(data, pre_ent);
  91         list_del(&entry->list);
  92
  93         return 0;
  94 }
  95
  96 void free_input_mapper_list(struct list_head *head)
  97 {
  98         struct imapper *entry;
  99         struct list_head *pos;
 100
 101         while (!list_empty(head)) {
 102                 pos = head->next;
 103                 list_del(pos);
 104                 entry = list_entry(pos, struct imapper, list);
 105                 kfree(entry);
 106         }
 107 }
 108