Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
7785925d | 2 | * w1_family.c |
1da177e4 | 3 | * |
a8018766 | 4 | * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net> |
7785925d | 5 | * |
1da177e4 LT |
6 | * |
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> | |
4e57b681 | 24 | #include <linux/sched.h> /* schedule_timeout() */ |
1da177e4 | 25 | #include <linux/delay.h> |
9623932c | 26 | #include <linux/export.h> |
1da177e4 LT |
27 | |
28 | #include "w1_family.h" | |
a9fb1c7b | 29 | #include "w1.h" |
1da177e4 LT |
30 | |
31 | DEFINE_SPINLOCK(w1_flock); | |
32 | static LIST_HEAD(w1_families); | |
33 | ||
1da177e4 LT |
34 | int w1_register_family(struct w1_family *newf) |
35 | { | |
36 | struct list_head *ent, *n; | |
37 | struct w1_family *f; | |
38 | int ret = 0; | |
39 | ||
1da177e4 LT |
40 | spin_lock(&w1_flock); |
41 | list_for_each_safe(ent, n, &w1_families) { | |
42 | f = list_entry(ent, struct w1_family, family_entry); | |
43 | ||
44 | if (f->fid == newf->fid) { | |
45 | ret = -EEXIST; | |
46 | break; | |
47 | } | |
48 | } | |
49 | ||
50 | if (!ret) { | |
51 | atomic_set(&newf->refcnt, 0); | |
1da177e4 LT |
52 | list_add_tail(&newf->family_entry, &w1_families); |
53 | } | |
1da177e4 LT |
54 | spin_unlock(&w1_flock); |
55 | ||
c30c9b15 DF |
56 | /* check default devices against the new set of drivers */ |
57 | w1_reconnect_slaves(newf, 1); | |
6adf87bd | 58 | |
1da177e4 LT |
59 | return ret; |
60 | } | |
61 | ||
62 | void w1_unregister_family(struct w1_family *fent) | |
63 | { | |
64 | struct list_head *ent, *n; | |
65 | struct w1_family *f; | |
66 | ||
67 | spin_lock(&w1_flock); | |
68 | list_for_each_safe(ent, n, &w1_families) { | |
69 | f = list_entry(ent, struct w1_family, family_entry); | |
70 | ||
71 | if (f->fid == fent->fid) { | |
72 | list_del(&fent->family_entry); | |
73 | break; | |
74 | } | |
75 | } | |
1da177e4 LT |
76 | spin_unlock(&w1_flock); |
77 | ||
c30c9b15 DF |
78 | /* deatch devices using this family code */ |
79 | w1_reconnect_slaves(fent, 0); | |
80 | ||
1da177e4 LT |
81 | while (atomic_read(&fent->refcnt)) { |
82 | printk(KERN_INFO "Waiting for family %u to become free: refcnt=%d.\n", | |
83 | fent->fid, atomic_read(&fent->refcnt)); | |
84 | ||
85 | if (msleep_interruptible(1000)) | |
86 | flush_signals(current); | |
87 | } | |
88 | } | |
89 | ||
90 | /* | |
91 | * Should be called under w1_flock held. | |
92 | */ | |
93 | struct w1_family * w1_family_registered(u8 fid) | |
94 | { | |
95 | struct list_head *ent, *n; | |
96 | struct w1_family *f = NULL; | |
97 | int ret = 0; | |
98 | ||
99 | list_for_each_safe(ent, n, &w1_families) { | |
100 | f = list_entry(ent, struct w1_family, family_entry); | |
101 | ||
102 | if (f->fid == fid) { | |
103 | ret = 1; | |
104 | break; | |
105 | } | |
106 | } | |
107 | ||
108 | return (ret) ? f : NULL; | |
109 | } | |
110 | ||
70d484bf EP |
111 | static void __w1_family_put(struct w1_family *f) |
112 | { | |
fe3cb823 | 113 | atomic_dec(&f->refcnt); |
70d484bf EP |
114 | } |
115 | ||
1da177e4 LT |
116 | void w1_family_put(struct w1_family *f) |
117 | { | |
118 | spin_lock(&w1_flock); | |
119 | __w1_family_put(f); | |
120 | spin_unlock(&w1_flock); | |
121 | } | |
122 | ||
70d484bf | 123 | #if 0 |
1da177e4 LT |
124 | void w1_family_get(struct w1_family *f) |
125 | { | |
126 | spin_lock(&w1_flock); | |
127 | __w1_family_get(f); | |
128 | spin_unlock(&w1_flock); | |
1da177e4 | 129 | } |
70d484bf | 130 | #endif /* 0 */ |
1da177e4 LT |
131 | |
132 | void __w1_family_get(struct w1_family *f) | |
133 | { | |
134 | smp_mb__before_atomic_inc(); | |
135 | atomic_inc(&f->refcnt); | |
136 | smp_mb__after_atomic_inc(); | |
137 | } | |
138 | ||
1da177e4 LT |
139 | EXPORT_SYMBOL(w1_unregister_family); |
140 | EXPORT_SYMBOL(w1_register_family); |