blob: 47249a30eae38e4c80078086c3a1b33309e6eeb9 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Evgeniy Polyakov77859252005-05-20 22:33:25 +04002 * w1_int.c
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 *
Evgeniy Polyakova8018762011-08-25 15:59:06 -07004 * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
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/kernel.h>
23#include <linux/list.h>
24#include <linux/delay.h>
Evgeniy Polyakov674a396c2006-02-20 11:15:37 +030025#include <linux/kthread.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090026#include <linux/slab.h>
Paul Gortmaker96239322011-07-10 13:21:52 -040027#include <linux/export.h>
Paul Gortmaker4d184122011-09-15 23:09:52 -040028#include <linux/moduleparam.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070029
30#include "w1.h"
31#include "w1_log.h"
32#include "w1_netlink.h"
Evgeniy Polyakov70d484b2006-04-24 10:46:14 +040033#include "w1_int.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
David Fries9141f572008-10-15 22:04:45 -070035static int w1_search_count = -1; /* Default is continual scan */
36module_param_named(search_count, w1_search_count, int, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -070037
David Fries6a158c02008-10-15 22:04:42 -070038static int w1_enable_pullup = 1;
39module_param_named(enable_pullup, w1_enable_pullup, int, 0);
40
Thomas Wood7242d422014-05-30 16:10:20 -070041static struct w1_master *w1_alloc_dev(u32 id, int slave_count, int slave_ttl,
Evgeniy Polyakov77859252005-05-20 22:33:25 +040042 struct device_driver *driver,
43 struct device *device)
Linus Torvalds1da177e2005-04-16 15:20:36 -070044{
45 struct w1_master *dev;
46 int err;
47
48 /*
49 * We are in process context(kernel thread), so can sleep.
50 */
Yoann Padioleaudd00cc42007-07-19 01:49:03 -070051 dev = kzalloc(sizeof(struct w1_master) + sizeof(struct w1_bus_master), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070052 if (!dev) {
Fjodor Schelichowfdc91672014-06-19 02:52:00 +020053 pr_err("Failed to allocate %zd bytes for new w1 device.\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 sizeof(struct w1_master));
55 return NULL;
56 }
57
Linus Torvalds1da177e2005-04-16 15:20:36 -070058
59 dev->bus_master = (struct w1_bus_master *)(dev + 1);
60
Evgeniy Polyakov77859252005-05-20 22:33:25 +040061 dev->owner = THIS_MODULE;
62 dev->max_slave_count = slave_count;
63 dev->slave_count = 0;
64 dev->attempts = 0;
Evgeniy Polyakov77859252005-05-20 22:33:25 +040065 dev->initialized = 0;
66 dev->id = id;
Linus Torvalds1da177e2005-04-16 15:20:36 -070067 dev->slave_ttl = slave_ttl;
David Fries9141f572008-10-15 22:04:45 -070068 dev->search_count = w1_search_count;
David Fries6a158c02008-10-15 22:04:42 -070069 dev->enable_pullup = w1_enable_pullup;
Linus Torvalds1da177e2005-04-16 15:20:36 -070070
David Fries01e14d62008-10-15 22:04:40 -070071 /* 1 for w1_process to decrement
72 * 1 for __w1_remove_master_device to decrement
73 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 atomic_set(&dev->refcnt, 2);
75
76 INIT_LIST_HEAD(&dev->slist);
David Fries9fcbbac2014-01-15 22:29:18 -060077 INIT_LIST_HEAD(&dev->async_list);
Evgeniy Polyakovabd52a12006-04-03 12:04:27 +040078 mutex_init(&dev->mutex);
NeilBrownb02f8be2012-05-18 15:59:52 +100079 mutex_init(&dev->bus_mutex);
David Fries9fcbbac2014-01-15 22:29:18 -060080 mutex_init(&dev->list_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070081
Linus Torvalds1da177e2005-04-16 15:20:36 -070082 memcpy(&dev->dev, device, sizeof(struct device));
Kay Sievers40f91de2009-01-06 10:44:34 -080083 dev_set_name(&dev->dev, "w1_bus_master%u", dev->id);
Linus Torvalds1da177e2005-04-16 15:20:36 -070084 snprintf(dev->name, sizeof(dev->name), "w1_bus_master%u", dev->id);
Florian Faber68a436a2011-11-02 13:39:59 -070085 dev->dev.init_name = dev->name;
Linus Torvalds1da177e2005-04-16 15:20:36 -070086
87 dev->driver = driver;
88
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 dev->seq = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -070090
91 err = device_register(&dev->dev);
92 if (err) {
Fjodor Schelichowfdc91672014-06-19 02:52:00 +020093 pr_err("Failed to register master device. err=%d\n", err);
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 memset(dev, 0, sizeof(struct w1_master));
95 kfree(dev);
96 dev = NULL;
97 }
98
99 return dev;
100}
101
Evgeniy Polyakov2c5bfda2006-04-04 20:35:22 +0400102static void w1_free_dev(struct w1_master *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103{
104 device_unregister(&dev->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105}
106
David Friesb3be1772014-01-15 22:29:25 -0600107/**
108 * w1_add_master_device() - registers a new master device
109 * @master: master bus device to register
110 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111int w1_add_master_device(struct w1_bus_master *master)
112{
David Friesaf00a2d2008-10-15 22:04:53 -0700113 struct w1_master *dev, *entry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 int retval = 0;
115 struct w1_netlink_msg msg;
David Friesaf00a2d2008-10-15 22:04:53 -0700116 int id, found;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117
Thomas Wood7242d422014-05-30 16:10:20 -0700118 /* validate minimum functionality */
119 if (!(master->touch_bit && master->reset_bus) &&
120 !(master->write_bit && master->read_bit) &&
Evgeniy Polyakovc1f858b2007-05-08 00:31:20 -0700121 !(master->write_byte && master->read_byte && master->reset_bus)) {
Fjodor Schelichowfdc91672014-06-19 02:52:00 +0200122 pr_err("w1_add_master_device: invalid function set\n");
Evgeniy Polyakov6adf87b2005-06-04 01:29:25 +0400123 return(-EINVAL);
Thomas Wood7242d422014-05-30 16:10:20 -0700124 }
Evgeniy Polyakovbe57ce22005-06-04 01:21:46 +0400125
David Friesaf00a2d2008-10-15 22:04:53 -0700126 /* Lock until the device is added (or not) to w1_masters. */
127 mutex_lock(&w1_mlock);
128 /* Search for the first available id (starting at 1). */
129 id = 0;
130 do {
131 ++id;
132 found = 0;
133 list_for_each_entry(entry, &w1_masters, w1_master_entry) {
134 if (entry->id == id) {
135 found = 1;
136 break;
137 }
138 }
139 } while (found);
140
141 dev = w1_alloc_dev(id, w1_max_slave_count, w1_max_slave_ttl,
142 &w1_master_driver, &w1_master_device);
143 if (!dev) {
144 mutex_unlock(&w1_mlock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 return -ENOMEM;
David Friesaf00a2d2008-10-15 22:04:53 -0700146 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147
David Fries01e14d62008-10-15 22:04:40 -0700148 retval = w1_create_master_attributes(dev);
David Friesaf00a2d2008-10-15 22:04:53 -0700149 if (retval) {
150 mutex_unlock(&w1_mlock);
David Fries01e14d62008-10-15 22:04:40 -0700151 goto err_out_free_dev;
David Friesaf00a2d2008-10-15 22:04:53 -0700152 }
David Fries01e14d62008-10-15 22:04:40 -0700153
154 memcpy(dev->bus_master, master, sizeof(struct w1_bus_master));
155
156 dev->initialized = 1;
157
Evgeniy Polyakov674a396c2006-02-20 11:15:37 +0300158 dev->thread = kthread_run(&w1_process, dev, "%s", dev->name);
159 if (IS_ERR(dev->thread)) {
160 retval = PTR_ERR(dev->thread);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161 dev_err(&dev->dev,
162 "Failed to create new kernel thread. err=%d\n",
Evgeniy Polyakov674a396c2006-02-20 11:15:37 +0300163 retval);
David Friesaf00a2d2008-10-15 22:04:53 -0700164 mutex_unlock(&w1_mlock);
David Fries01e14d62008-10-15 22:04:40 -0700165 goto err_out_rm_attr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 }
167
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 list_add(&dev->w1_master_entry, &w1_masters);
Evgeniy Polyakovabd52a12006-04-03 12:04:27 +0400169 mutex_unlock(&w1_mlock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170
Evgeniy Polyakov12003372006-03-23 19:11:58 +0300171 memset(&msg, 0, sizeof(msg));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 msg.id.mst.id = dev->id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 msg.type = W1_MASTER_ADD;
174 w1_netlink_send(dev, &msg);
175
176 return 0;
177
David Fries01e14d62008-10-15 22:04:40 -0700178#if 0 /* Thread cleanup code, not required currently. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179err_out_kill_thread:
David Fries42105692014-01-15 22:29:13 -0600180 set_bit(W1_ABORT_SEARCH, &dev->flags);
Evgeniy Polyakov674a396c2006-02-20 11:15:37 +0300181 kthread_stop(dev->thread);
David Fries01e14d62008-10-15 22:04:40 -0700182#endif
183err_out_rm_attr:
184 w1_destroy_master_attributes(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185err_out_free_dev:
186 w1_free_dev(dev);
187
188 return retval;
189}
190
191void __w1_remove_master_device(struct w1_master *dev)
192{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 struct w1_netlink_msg msg;
David Friesc30c9b12008-10-15 22:04:38 -0700194 struct w1_slave *sl, *sln;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195
David Friesc30c9b12008-10-15 22:04:38 -0700196 mutex_lock(&w1_mlock);
197 list_del(&dev->w1_master_entry);
198 mutex_unlock(&w1_mlock);
199
David Fries9fcbbac2014-01-15 22:29:18 -0600200 set_bit(W1_ABORT_SEARCH, &dev->flags);
201 kthread_stop(dev->thread);
202
David Friesc30c9b12008-10-15 22:04:38 -0700203 mutex_lock(&dev->mutex);
David Fries9fcbbac2014-01-15 22:29:18 -0600204 mutex_lock(&dev->list_mutex);
205 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
206 mutex_unlock(&dev->list_mutex);
David Friesc30c9b12008-10-15 22:04:38 -0700207 w1_slave_detach(sl);
David Fries9fcbbac2014-01-15 22:29:18 -0600208 mutex_lock(&dev->list_mutex);
209 }
David Friesc30c9b12008-10-15 22:04:38 -0700210 w1_destroy_master_attributes(dev);
David Fries9fcbbac2014-01-15 22:29:18 -0600211 mutex_unlock(&dev->list_mutex);
David Friesc30c9b12008-10-15 22:04:38 -0700212 mutex_unlock(&dev->mutex);
213 atomic_dec(&dev->refcnt);
214
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 while (atomic_read(&dev->refcnt)) {
Evgeniy Polyakov674a396c2006-02-20 11:15:37 +0300216 dev_info(&dev->dev, "Waiting for %s to become free: refcnt=%d.\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 dev->name, atomic_read(&dev->refcnt));
218
219 if (msleep_interruptible(1000))
220 flush_signals(current);
Alexey Khoroshilova0f10462014-05-07 01:26:04 +0400221 mutex_lock(&dev->list_mutex);
David Fries9fcbbac2014-01-15 22:29:18 -0600222 w1_process_callbacks(dev);
Alexey Khoroshilova0f10462014-05-07 01:26:04 +0400223 mutex_unlock(&dev->list_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 }
Alexey Khoroshilova0f10462014-05-07 01:26:04 +0400225 mutex_lock(&dev->list_mutex);
David Fries9fcbbac2014-01-15 22:29:18 -0600226 w1_process_callbacks(dev);
Alexey Khoroshilova0f10462014-05-07 01:26:04 +0400227 mutex_unlock(&dev->list_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228
Evgeniy Polyakov12003372006-03-23 19:11:58 +0300229 memset(&msg, 0, sizeof(msg));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 msg.id.mst.id = dev->id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 msg.type = W1_MASTER_REMOVE;
232 w1_netlink_send(dev, &msg);
233
234 w1_free_dev(dev);
235}
236
David Friesb3be1772014-01-15 22:29:25 -0600237/**
238 * w1_remove_master_device() - unregister a master device
239 * @bm: master bus device to remove
240 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241void w1_remove_master_device(struct w1_bus_master *bm)
242{
Evgeniy Polyakov59d94452007-08-22 14:01:51 -0700243 struct w1_master *dev, *found = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244
Evgeniy Polyakov77859252005-05-20 22:33:25 +0400245 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 if (!dev->initialized)
247 continue;
248
Evgeniy Polyakov59d94452007-08-22 14:01:51 -0700249 if (dev->bus_master->data == bm->data) {
250 found = dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251 break;
Evgeniy Polyakov59d94452007-08-22 14:01:51 -0700252 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253 }
254
Evgeniy Polyakov59d94452007-08-22 14:01:51 -0700255 if (!found) {
Fjodor Schelichowfdc91672014-06-19 02:52:00 +0200256 pr_err("Device doesn't exist.\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 return;
258 }
259
Evgeniy Polyakov59d94452007-08-22 14:01:51 -0700260 __w1_remove_master_device(found);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261}
262
263EXPORT_SYMBOL(w1_add_master_device);
264EXPORT_SYMBOL(w1_remove_master_device);