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 | ||
b3be177a DF |
34 | /** |
35 | * w1_register_family() - register a device family driver | |
36 | * @newf: family to register | |
37 | */ | |
1da177e4 LT |
38 | int w1_register_family(struct w1_family *newf) |
39 | { | |
40 | struct list_head *ent, *n; | |
41 | struct w1_family *f; | |
42 | int ret = 0; | |
43 | ||
1da177e4 LT |
44 | spin_lock(&w1_flock); |
45 | list_for_each_safe(ent, n, &w1_families) { | |
46 | f = list_entry(ent, struct w1_family, family_entry); | |
47 | ||
48 | if (f->fid == newf->fid) { | |
49 | ret = -EEXIST; | |
50 | break; | |
51 | } | |
52 | } | |
53 | ||
54 | if (!ret) { | |
55 | atomic_set(&newf->refcnt, 0); | |
1da177e4 LT |
56 | list_add_tail(&newf->family_entry, &w1_families); |
57 | } | |
1da177e4 LT |
58 | spin_unlock(&w1_flock); |
59 | ||
c30c9b15 DF |
60 | /* check default devices against the new set of drivers */ |
61 | w1_reconnect_slaves(newf, 1); | |
6adf87bd | 62 | |
1da177e4 LT |
63 | return ret; |
64 | } | |
65 | ||
b3be177a DF |
66 | /** |
67 | * w1_unregister_family() - unregister a device family driver | |
68 | * @fent: family to unregister | |
69 | */ | |
1da177e4 LT |
70 | void w1_unregister_family(struct w1_family *fent) |
71 | { | |
72 | struct list_head *ent, *n; | |
73 | struct w1_family *f; | |
74 | ||
75 | spin_lock(&w1_flock); | |
76 | list_for_each_safe(ent, n, &w1_families) { | |
77 | f = list_entry(ent, struct w1_family, family_entry); | |
78 | ||
79 | if (f->fid == fent->fid) { | |
80 | list_del(&fent->family_entry); | |
81 | break; | |
82 | } | |
83 | } | |
1da177e4 LT |
84 | spin_unlock(&w1_flock); |
85 | ||
c30c9b15 DF |
86 | /* deatch devices using this family code */ |
87 | w1_reconnect_slaves(fent, 0); | |
88 | ||
1da177e4 | 89 | while (atomic_read(&fent->refcnt)) { |
fdc9167a | 90 | pr_info("Waiting for family %u to become free: refcnt=%d.\n", |
1da177e4 LT |
91 | fent->fid, atomic_read(&fent->refcnt)); |
92 | ||
93 | if (msleep_interruptible(1000)) | |
94 | flush_signals(current); | |
95 | } | |
96 | } | |
97 | ||
98 | /* | |
99 | * Should be called under w1_flock held. | |
100 | */ | |
101 | struct w1_family * w1_family_registered(u8 fid) | |
102 | { | |
103 | struct list_head *ent, *n; | |
104 | struct w1_family *f = NULL; | |
105 | int ret = 0; | |
106 | ||
107 | list_for_each_safe(ent, n, &w1_families) { | |
108 | f = list_entry(ent, struct w1_family, family_entry); | |
109 | ||
110 | if (f->fid == fid) { | |
111 | ret = 1; | |
112 | break; | |
113 | } | |
114 | } | |
115 | ||
116 | return (ret) ? f : NULL; | |
117 | } | |
118 | ||
70d484bf EP |
119 | static void __w1_family_put(struct w1_family *f) |
120 | { | |
fe3cb823 | 121 | atomic_dec(&f->refcnt); |
70d484bf EP |
122 | } |
123 | ||
1da177e4 LT |
124 | void w1_family_put(struct w1_family *f) |
125 | { | |
126 | spin_lock(&w1_flock); | |
127 | __w1_family_put(f); | |
128 | spin_unlock(&w1_flock); | |
129 | } | |
130 | ||
70d484bf | 131 | #if 0 |
1da177e4 LT |
132 | void w1_family_get(struct w1_family *f) |
133 | { | |
134 | spin_lock(&w1_flock); | |
135 | __w1_family_get(f); | |
136 | spin_unlock(&w1_flock); | |
1da177e4 | 137 | } |
70d484bf | 138 | #endif /* 0 */ |
1da177e4 LT |
139 | |
140 | void __w1_family_get(struct w1_family *f) | |
141 | { | |
4e857c58 | 142 | smp_mb__before_atomic(); |
1da177e4 | 143 | atomic_inc(&f->refcnt); |
4e857c58 | 144 | smp_mb__after_atomic(); |
1da177e4 LT |
145 | } |
146 | ||
1da177e4 LT |
147 | EXPORT_SYMBOL(w1_unregister_family); |
148 | EXPORT_SYMBOL(w1_register_family); |