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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 *
4 * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
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 Polyakov674a3962006-02-20 11:15:37 +030025#include <linux/kthread.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026
27#include "w1.h"
28#include "w1_log.h"
29#include "w1_netlink.h"
Evgeniy Polyakov70d484b2006-04-24 10:46:14 +040030#include "w1_int.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
David Fries9141f572008-10-15 22:04:45 -070032static int w1_search_count = -1; /* Default is continual scan */
33module_param_named(search_count, w1_search_count, int, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
David Fries6a158c02008-10-15 22:04:42 -070035static int w1_enable_pullup = 1;
36module_param_named(enable_pullup, w1_enable_pullup, int, 0);
37
Evgeniy Polyakov77859252005-05-20 22:33:25 +040038static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl,
39 struct device_driver *driver,
40 struct device *device)
Linus Torvalds1da177e2005-04-16 15:20:36 -070041{
42 struct w1_master *dev;
43 int err;
44
45 /*
46 * We are in process context(kernel thread), so can sleep.
47 */
Yoann Padioleaudd00cc42007-07-19 01:49:03 -070048 dev = kzalloc(sizeof(struct w1_master) + sizeof(struct w1_bus_master), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070049 if (!dev) {
50 printk(KERN_ERR
51 "Failed to allocate %zd bytes for new w1 device.\n",
52 sizeof(struct w1_master));
53 return NULL;
54 }
55
Linus Torvalds1da177e2005-04-16 15:20:36 -070056
57 dev->bus_master = (struct w1_bus_master *)(dev + 1);
58
Evgeniy Polyakov77859252005-05-20 22:33:25 +040059 dev->owner = THIS_MODULE;
60 dev->max_slave_count = slave_count;
61 dev->slave_count = 0;
62 dev->attempts = 0;
Evgeniy Polyakov77859252005-05-20 22:33:25 +040063 dev->initialized = 0;
64 dev->id = id;
Linus Torvalds1da177e2005-04-16 15:20:36 -070065 dev->slave_ttl = slave_ttl;
David Fries9141f572008-10-15 22:04:45 -070066 dev->search_count = w1_search_count;
David Fries6a158c02008-10-15 22:04:42 -070067 dev->enable_pullup = w1_enable_pullup;
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
David Fries01e14d62008-10-15 22:04:40 -070069 /* 1 for w1_process to decrement
70 * 1 for __w1_remove_master_device to decrement
71 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 atomic_set(&dev->refcnt, 2);
73
74 INIT_LIST_HEAD(&dev->slist);
Evgeniy Polyakovabd52a12006-04-03 12:04:27 +040075 mutex_init(&dev->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070076
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 memcpy(&dev->dev, device, sizeof(struct device));
Kay Sievers40f91de2009-01-06 10:44:34 -080078 dev_set_name(&dev->dev, "w1_bus_master%u", dev->id);
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 snprintf(dev->name, sizeof(dev->name), "w1_bus_master%u", dev->id);
80
81 dev->driver = driver;
82
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 dev->seq = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -070084
85 err = device_register(&dev->dev);
86 if (err) {
87 printk(KERN_ERR "Failed to register master device. err=%d\n", err);
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 memset(dev, 0, sizeof(struct w1_master));
89 kfree(dev);
90 dev = NULL;
91 }
92
93 return dev;
94}
95
Evgeniy Polyakov2c5bfda2006-04-04 20:35:22 +040096static void w1_free_dev(struct w1_master *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -070097{
98 device_unregister(&dev->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -070099}
100
101int w1_add_master_device(struct w1_bus_master *master)
102{
David Friesaf00a2d2008-10-15 22:04:53 -0700103 struct w1_master *dev, *entry;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104 int retval = 0;
105 struct w1_netlink_msg msg;
David Friesaf00a2d2008-10-15 22:04:53 -0700106 int id, found;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107
Evgeniy Polyakovbe57ce22005-06-04 01:21:46 +0400108 /* validate minimum functionality */
109 if (!(master->touch_bit && master->reset_bus) &&
Evgeniy Polyakovc1f858b2007-05-08 00:31:20 -0700110 !(master->write_bit && master->read_bit) &&
111 !(master->write_byte && master->read_byte && master->reset_bus)) {
Evgeniy Polyakov6adf87b2005-06-04 01:29:25 +0400112 printk(KERN_ERR "w1_add_master_device: invalid function set\n");
113 return(-EINVAL);
Evgeniy Polyakovbe57ce22005-06-04 01:21:46 +0400114 }
David Fries6a158c02008-10-15 22:04:42 -0700115 /* While it would be electrically possible to make a device that
116 * generated a strong pullup in bit bang mode, only hardare that
117 * controls 1-wire time frames are even expected to support a strong
118 * pullup. w1_io.c would need to support calling set_pullup before
119 * the last write_bit operation of a w1_write_8 which it currently
120 * doesn't.
121 */
122 if (!master->write_byte && !master->touch_bit && master->set_pullup) {
123 printk(KERN_ERR "w1_add_master_device: set_pullup requires "
124 "write_byte or touch_bit, disabling\n");
125 master->set_pullup = NULL;
126 }
Evgeniy Polyakovbe57ce22005-06-04 01:21:46 +0400127
David Friesaf00a2d2008-10-15 22:04:53 -0700128 /* Lock until the device is added (or not) to w1_masters. */
129 mutex_lock(&w1_mlock);
130 /* Search for the first available id (starting at 1). */
131 id = 0;
132 do {
133 ++id;
134 found = 0;
135 list_for_each_entry(entry, &w1_masters, w1_master_entry) {
136 if (entry->id == id) {
137 found = 1;
138 break;
139 }
140 }
141 } while (found);
142
143 dev = w1_alloc_dev(id, w1_max_slave_count, w1_max_slave_ttl,
144 &w1_master_driver, &w1_master_device);
145 if (!dev) {
146 mutex_unlock(&w1_mlock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 return -ENOMEM;
David Friesaf00a2d2008-10-15 22:04:53 -0700148 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149
David Fries01e14d62008-10-15 22:04:40 -0700150 retval = w1_create_master_attributes(dev);
David Friesaf00a2d2008-10-15 22:04:53 -0700151 if (retval) {
152 mutex_unlock(&w1_mlock);
David Fries01e14d62008-10-15 22:04:40 -0700153 goto err_out_free_dev;
David Friesaf00a2d2008-10-15 22:04:53 -0700154 }
David Fries01e14d62008-10-15 22:04:40 -0700155
156 memcpy(dev->bus_master, master, sizeof(struct w1_bus_master));
157
158 dev->initialized = 1;
159
Evgeniy Polyakov674a3962006-02-20 11:15:37 +0300160 dev->thread = kthread_run(&w1_process, dev, "%s", dev->name);
161 if (IS_ERR(dev->thread)) {
162 retval = PTR_ERR(dev->thread);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 dev_err(&dev->dev,
164 "Failed to create new kernel thread. err=%d\n",
Evgeniy Polyakov674a3962006-02-20 11:15:37 +0300165 retval);
David Friesaf00a2d2008-10-15 22:04:53 -0700166 mutex_unlock(&w1_mlock);
David Fries01e14d62008-10-15 22:04:40 -0700167 goto err_out_rm_attr;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 }
169
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170 list_add(&dev->w1_master_entry, &w1_masters);
Evgeniy Polyakovabd52a12006-04-03 12:04:27 +0400171 mutex_unlock(&w1_mlock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172
Evgeniy Polyakov12003372006-03-23 19:11:58 +0300173 memset(&msg, 0, sizeof(msg));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 msg.id.mst.id = dev->id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 msg.type = W1_MASTER_ADD;
176 w1_netlink_send(dev, &msg);
177
178 return 0;
179
David Fries01e14d62008-10-15 22:04:40 -0700180#if 0 /* Thread cleanup code, not required currently. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181err_out_kill_thread:
Evgeniy Polyakov674a3962006-02-20 11:15:37 +0300182 kthread_stop(dev->thread);
David Fries01e14d62008-10-15 22:04:40 -0700183#endif
184err_out_rm_attr:
185 w1_destroy_master_attributes(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186err_out_free_dev:
187 w1_free_dev(dev);
188
189 return retval;
190}
191
192void __w1_remove_master_device(struct w1_master *dev)
193{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 struct w1_netlink_msg msg;
David Friesc30c9b12008-10-15 22:04:38 -0700195 struct w1_slave *sl, *sln;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700196
Evgeniy Polyakov674a3962006-02-20 11:15:37 +0300197 kthread_stop(dev->thread);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198
David Friesc30c9b12008-10-15 22:04:38 -0700199 mutex_lock(&w1_mlock);
200 list_del(&dev->w1_master_entry);
201 mutex_unlock(&w1_mlock);
202
203 mutex_lock(&dev->mutex);
204 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry)
205 w1_slave_detach(sl);
206 w1_destroy_master_attributes(dev);
207 mutex_unlock(&dev->mutex);
208 atomic_dec(&dev->refcnt);
209
Linus Torvalds1da177e2005-04-16 15:20:36 -0700210 while (atomic_read(&dev->refcnt)) {
Evgeniy Polyakov674a3962006-02-20 11:15:37 +0300211 dev_info(&dev->dev, "Waiting for %s to become free: refcnt=%d.\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212 dev->name, atomic_read(&dev->refcnt));
213
214 if (msleep_interruptible(1000))
215 flush_signals(current);
216 }
217
Evgeniy Polyakov12003372006-03-23 19:11:58 +0300218 memset(&msg, 0, sizeof(msg));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 msg.id.mst.id = dev->id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 msg.type = W1_MASTER_REMOVE;
221 w1_netlink_send(dev, &msg);
222
223 w1_free_dev(dev);
224}
225
226void w1_remove_master_device(struct w1_bus_master *bm)
227{
Evgeniy Polyakov59d94452007-08-22 14:01:51 -0700228 struct w1_master *dev, *found = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229
Evgeniy Polyakov77859252005-05-20 22:33:25 +0400230 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 if (!dev->initialized)
232 continue;
233
Evgeniy Polyakov59d94452007-08-22 14:01:51 -0700234 if (dev->bus_master->data == bm->data) {
235 found = dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 break;
Evgeniy Polyakov59d94452007-08-22 14:01:51 -0700237 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700238 }
239
Evgeniy Polyakov59d94452007-08-22 14:01:51 -0700240 if (!found) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 printk(KERN_ERR "Device doesn't exist.\n");
242 return;
243 }
244
Evgeniy Polyakov59d94452007-08-22 14:01:51 -0700245 __w1_remove_master_device(found);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246}
247
248EXPORT_SYMBOL(w1_add_master_device);
249EXPORT_SYMBOL(w1_remove_master_device);