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git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - drivers/w1/w1_family.c
2 * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
15 #include <linux/spinlock.h>
16 #include <linux/list.h>
17 #include <linux/sched.h> /* schedule_timeout() */
18 #include <linux/delay.h>
19 #include <linux/export.h>
21 #include "w1_family.h"
24 DEFINE_SPINLOCK(w1_flock
);
25 static LIST_HEAD(w1_families
);
28 * w1_register_family() - register a device family driver
29 * @newf: family to register
31 int w1_register_family(struct w1_family
*newf
)
33 struct list_head
*ent
, *n
;
38 list_for_each_safe(ent
, n
, &w1_families
) {
39 f
= list_entry(ent
, struct w1_family
, family_entry
);
41 if (f
->fid
== newf
->fid
) {
48 atomic_set(&newf
->refcnt
, 0);
49 list_add_tail(&newf
->family_entry
, &w1_families
);
51 spin_unlock(&w1_flock
);
53 /* check default devices against the new set of drivers */
54 w1_reconnect_slaves(newf
, 1);
60 * w1_unregister_family() - unregister a device family driver
61 * @fent: family to unregister
63 void w1_unregister_family(struct w1_family
*fent
)
65 struct list_head
*ent
, *n
;
69 list_for_each_safe(ent
, n
, &w1_families
) {
70 f
= list_entry(ent
, struct w1_family
, family_entry
);
72 if (f
->fid
== fent
->fid
) {
73 list_del(&fent
->family_entry
);
77 spin_unlock(&w1_flock
);
79 /* deatch devices using this family code */
80 w1_reconnect_slaves(fent
, 0);
82 while (atomic_read(&fent
->refcnt
)) {
83 pr_info("Waiting for family %u to become free: refcnt=%d.\n",
84 fent
->fid
, atomic_read(&fent
->refcnt
));
86 if (msleep_interruptible(1000))
87 flush_signals(current
);
92 * Should be called under w1_flock held.
94 struct w1_family
* w1_family_registered(u8 fid
)
96 struct list_head
*ent
, *n
;
97 struct w1_family
*f
= NULL
;
100 list_for_each_safe(ent
, n
, &w1_families
) {
101 f
= list_entry(ent
, struct w1_family
, family_entry
);
109 return (ret
) ? f
: NULL
;
112 static void __w1_family_put(struct w1_family
*f
)
114 atomic_dec(&f
->refcnt
);
117 void w1_family_put(struct w1_family
*f
)
119 spin_lock(&w1_flock
);
121 spin_unlock(&w1_flock
);
125 void w1_family_get(struct w1_family
*f
)
127 spin_lock(&w1_flock
);
129 spin_unlock(&w1_flock
);
133 void __w1_family_get(struct w1_family
*f
)
135 smp_mb__before_atomic();
136 atomic_inc(&f
->refcnt
);
137 smp_mb__after_atomic();
140 EXPORT_SYMBOL(w1_unregister_family
);
141 EXPORT_SYMBOL(w1_register_family
);