11da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 27785925dd8e0d2f389d4a9168f1683c6b249a552Evgeniy Polyakov * w1_family.c 31da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 4a801876638c5ce650223476c4eb8f37cea32dc1cEvgeniy Polyakov * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net> 57785925dd8e0d2f389d4a9168f1683c6b249a552Evgeniy Polyakov * 61da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 71da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * This program is free software; you can redistribute it and/or modify 81da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * it under the terms of the GNU General Public License as published by 91da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * the Free Software Foundation; either version 2 of the License, or 101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * (at your option) any later version. 111da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 121da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * This program is distributed in the hope that it will be useful, 131da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * but WITHOUT ANY WARRANTY; without even the implied warranty of 141da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 151da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * GNU General Public License for more details. 161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * 171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * You should have received a copy of the GNU General Public License 181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * along with this program; if not, write to the Free Software 191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/spinlock.h> 231da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/list.h> 244e57b6817880946a3a78d5d8cad1ace363f7e449Tim Schmielau#include <linux/sched.h> /* schedule_timeout() */ 251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include <linux/delay.h> 269623932cd5815e280cef5ebb54b5ee92bec382adPaul Gortmaker#include <linux/export.h> 271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds#include "w1_family.h" 29a9fb1c7b950bed4afe208c9d67e20f086bb6abbbAdrian Bunk#include "w1.h" 301da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsDEFINE_SPINLOCK(w1_flock); 321da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstatic LIST_HEAD(w1_families); 331da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsint w1_register_family(struct w1_family *newf) 351da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 361da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct list_head *ent, *n; 371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct w1_family *f; 381da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int ret = 0; 391da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 401da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds spin_lock(&w1_flock); 411da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds list_for_each_safe(ent, n, &w1_families) { 421da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds f = list_entry(ent, struct w1_family, family_entry); 431da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 441da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (f->fid == newf->fid) { 451da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds ret = -EEXIST; 461da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds break; 471da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 481da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 491da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 501da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (!ret) { 511da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds atomic_set(&newf->refcnt, 0); 521da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds list_add_tail(&newf->family_entry, &w1_families); 531da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 541da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds spin_unlock(&w1_flock); 551da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 56c30c9b15187e977ab5928f7276e9dfcd8d6f9460David Fries /* check default devices against the new set of drivers */ 57c30c9b15187e977ab5928f7276e9dfcd8d6f9460David Fries w1_reconnect_slaves(newf, 1); 586adf87bd7b7832105b9c6bc08adf6a4d229f1e79Evgeniy Polyakov 591da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return ret; 601da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 611da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 621da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsvoid w1_unregister_family(struct w1_family *fent) 631da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 641da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct list_head *ent, *n; 651da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct w1_family *f; 661da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 671da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds spin_lock(&w1_flock); 681da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds list_for_each_safe(ent, n, &w1_families) { 691da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds f = list_entry(ent, struct w1_family, family_entry); 701da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 711da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (f->fid == fent->fid) { 721da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds list_del(&fent->family_entry); 731da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds break; 741da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 751da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 761da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds spin_unlock(&w1_flock); 771da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 78c30c9b15187e977ab5928f7276e9dfcd8d6f9460David Fries /* deatch devices using this family code */ 79c30c9b15187e977ab5928f7276e9dfcd8d6f9460David Fries w1_reconnect_slaves(fent, 0); 80c30c9b15187e977ab5928f7276e9dfcd8d6f9460David Fries 811da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds while (atomic_read(&fent->refcnt)) { 821da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds printk(KERN_INFO "Waiting for family %u to become free: refcnt=%d.\n", 831da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds fent->fid, atomic_read(&fent->refcnt)); 841da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 851da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (msleep_interruptible(1000)) 861da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds flush_signals(current); 871da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 881da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 891da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 901da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds/* 911da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds * Should be called under w1_flock held. 921da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds */ 931da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsstruct w1_family * w1_family_registered(u8 fid) 941da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 951da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct list_head *ent, *n; 961da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds struct w1_family *f = NULL; 971da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds int ret = 0; 981da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 991da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds list_for_each_safe(ent, n, &w1_families) { 1001da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds f = list_entry(ent, struct w1_family, family_entry); 1011da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1021da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds if (f->fid == fid) { 1031da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds ret = 1; 1041da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds break; 1051da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 1061da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds } 1071da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1081da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds return (ret) ? f : NULL; 1091da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1101da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 11170d484bff43013e9b08f5d970b1c5941e9d98e16Evgeniy Polyakovstatic void __w1_family_put(struct w1_family *f) 11270d484bff43013e9b08f5d970b1c5941e9d98e16Evgeniy Polyakov{ 113fe3cb82364332b9db3b574e9e41de9c27eff470aDavid Fries atomic_dec(&f->refcnt); 11470d484bff43013e9b08f5d970b1c5941e9d98e16Evgeniy Polyakov} 11570d484bff43013e9b08f5d970b1c5941e9d98e16Evgeniy Polyakov 1161da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsvoid w1_family_put(struct w1_family *f) 1171da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 1181da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds spin_lock(&w1_flock); 1191da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __w1_family_put(f); 1201da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds spin_unlock(&w1_flock); 1211da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1221da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 12370d484bff43013e9b08f5d970b1c5941e9d98e16Evgeniy Polyakov#if 0 1241da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsvoid w1_family_get(struct w1_family *f) 1251da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 1261da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds spin_lock(&w1_flock); 1271da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds __w1_family_get(f); 1281da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds spin_unlock(&w1_flock); 1291da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 13070d484bff43013e9b08f5d970b1c5941e9d98e16Evgeniy Polyakov#endif /* 0 */ 1311da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1321da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvaldsvoid __w1_family_get(struct w1_family *f) 1331da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds{ 1341da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds smp_mb__before_atomic_inc(); 1351da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds atomic_inc(&f->refcnt); 1361da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds smp_mb__after_atomic_inc(); 1371da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds} 1381da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus Torvalds 1391da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsEXPORT_SYMBOL(w1_unregister_family); 1401da177e4c3f41524e886b7f1b8a0c1fc7321cacLinus TorvaldsEXPORT_SYMBOL(w1_register_family); 141