xref: /openbmc/linux/sound/pci/ctxfi/ctimap.c (revision e3b9f1e8)
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 
22 int 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 
68 int 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 
100 void 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