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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Evgeniy Polyakov77859252005-05-20 22:33:25 +04002 * w1_family.c
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 *
4 * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Evgeniy Polyakov77859252005-05-20 22:33:25 +04005 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22#include <linux/spinlock.h>
23#include <linux/list.h>
Tim Schmielau4e57b682005-10-30 15:03:48 -080024#include <linux/sched.h> /* schedule_timeout() */
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include <linux/delay.h>
26
27#include "w1_family.h"
Adrian Bunka9fb1c72005-12-13 14:04:33 -080028#include "w1.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070029
30DEFINE_SPINLOCK(w1_flock);
31static LIST_HEAD(w1_families);
32
Linus Torvalds1da177e2005-04-16 15:20:36 -070033int w1_register_family(struct w1_family *newf)
34{
35 struct list_head *ent, *n;
36 struct w1_family *f;
37 int ret = 0;
38
Linus Torvalds1da177e2005-04-16 15:20:36 -070039 spin_lock(&w1_flock);
40 list_for_each_safe(ent, n, &w1_families) {
41 f = list_entry(ent, struct w1_family, family_entry);
42
43 if (f->fid == newf->fid) {
44 ret = -EEXIST;
45 break;
46 }
47 }
48
49 if (!ret) {
50 atomic_set(&newf->refcnt, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -070051 list_add_tail(&newf->family_entry, &w1_families);
52 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070053 spin_unlock(&w1_flock);
54
David Friesc30c9b12008-10-15 22:04:38 -070055 /* check default devices against the new set of drivers */
56 w1_reconnect_slaves(newf, 1);
Evgeniy Polyakov6adf87b2005-06-04 01:29:25 +040057
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 return ret;
59}
60
61void w1_unregister_family(struct w1_family *fent)
62{
63 struct list_head *ent, *n;
64 struct w1_family *f;
65
66 spin_lock(&w1_flock);
67 list_for_each_safe(ent, n, &w1_families) {
68 f = list_entry(ent, struct w1_family, family_entry);
69
70 if (f->fid == fent->fid) {
71 list_del(&fent->family_entry);
72 break;
73 }
74 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 spin_unlock(&w1_flock);
76
David Friesc30c9b12008-10-15 22:04:38 -070077 /* deatch devices using this family code */
78 w1_reconnect_slaves(fent, 0);
79
Linus Torvalds1da177e2005-04-16 15:20:36 -070080 while (atomic_read(&fent->refcnt)) {
81 printk(KERN_INFO "Waiting for family %u to become free: refcnt=%d.\n",
82 fent->fid, atomic_read(&fent->refcnt));
83
84 if (msleep_interruptible(1000))
85 flush_signals(current);
86 }
87}
88
89/*
90 * Should be called under w1_flock held.
91 */
92struct w1_family * w1_family_registered(u8 fid)
93{
94 struct list_head *ent, *n;
95 struct w1_family *f = NULL;
96 int ret = 0;
97
98 list_for_each_safe(ent, n, &w1_families) {
99 f = list_entry(ent, struct w1_family, family_entry);
100
101 if (f->fid == fid) {
102 ret = 1;
103 break;
104 }
105 }
106
107 return (ret) ? f : NULL;
108}
109
Evgeniy Polyakov70d484b2006-04-24 10:46:14 +0400110static void __w1_family_put(struct w1_family *f)
111{
David Friesfe3cb822008-10-15 22:04:52 -0700112 atomic_dec(&f->refcnt);
Evgeniy Polyakov70d484b2006-04-24 10:46:14 +0400113}
114
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115void w1_family_put(struct w1_family *f)
116{
117 spin_lock(&w1_flock);
118 __w1_family_put(f);
119 spin_unlock(&w1_flock);
120}
121
Evgeniy Polyakov70d484b2006-04-24 10:46:14 +0400122#if 0
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123void w1_family_get(struct w1_family *f)
124{
125 spin_lock(&w1_flock);
126 __w1_family_get(f);
127 spin_unlock(&w1_flock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128}
Evgeniy Polyakov70d484b2006-04-24 10:46:14 +0400129#endif /* 0 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130
131void __w1_family_get(struct w1_family *f)
132{
133 smp_mb__before_atomic_inc();
134 atomic_inc(&f->refcnt);
135 smp_mb__after_atomic_inc();
136}
137
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138EXPORT_SYMBOL(w1_unregister_family);
139EXPORT_SYMBOL(w1_register_family);