4 * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
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.
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.
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
22 #include <linux/kernel.h>
23 #include <linux/list.h>
24 #include <linux/delay.h>
25 #include <linux/kthread.h>
29 #include "w1_netlink.h"
32 static u32 w1_ids = 1;
34 static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl,
35 struct device_driver *driver,
36 struct device *device)
38 struct w1_master *dev;
42 * We are in process context(kernel thread), so can sleep.
44 dev = kzalloc(sizeof(struct w1_master) + sizeof(struct w1_bus_master), GFP_KERNEL);
47 "Failed to allocate %zd bytes for new w1 device.\n",
48 sizeof(struct w1_master));
53 dev->bus_master = (struct w1_bus_master *)(dev + 1);
55 dev->owner = THIS_MODULE;
56 dev->max_slave_count = slave_count;
61 dev->slave_ttl = slave_ttl;
62 dev->search_count = -1; /* continual scan */
64 /* 1 for w1_process to decrement
65 * 1 for __w1_remove_master_device to decrement
67 atomic_set(&dev->refcnt, 2);
69 INIT_LIST_HEAD(&dev->slist);
70 mutex_init(&dev->mutex);
72 memcpy(&dev->dev, device, sizeof(struct device));
73 snprintf(dev->dev.bus_id, sizeof(dev->dev.bus_id),
74 "w1_bus_master%u", dev->id);
75 snprintf(dev->name, sizeof(dev->name), "w1_bus_master%u", dev->id);
81 err = device_register(&dev->dev);
83 printk(KERN_ERR "Failed to register master device. err=%d\n", err);
84 memset(dev, 0, sizeof(struct w1_master));
92 static void w1_free_dev(struct w1_master *dev)
94 device_unregister(&dev->dev);
97 int w1_add_master_device(struct w1_bus_master *master)
99 struct w1_master *dev;
101 struct w1_netlink_msg msg;
103 /* validate minimum functionality */
104 if (!(master->touch_bit && master->reset_bus) &&
105 !(master->write_bit && master->read_bit) &&
106 !(master->write_byte && master->read_byte && master->reset_bus)) {
107 printk(KERN_ERR "w1_add_master_device: invalid function set\n");
111 dev = w1_alloc_dev(w1_ids++, w1_max_slave_count, w1_max_slave_ttl, &w1_master_driver, &w1_master_device);
115 retval = w1_create_master_attributes(dev);
117 goto err_out_free_dev;
119 memcpy(dev->bus_master, master, sizeof(struct w1_bus_master));
121 dev->initialized = 1;
123 dev->thread = kthread_run(&w1_process, dev, "%s", dev->name);
124 if (IS_ERR(dev->thread)) {
125 retval = PTR_ERR(dev->thread);
127 "Failed to create new kernel thread. err=%d\n",
129 goto err_out_rm_attr;
132 mutex_lock(&w1_mlock);
133 list_add(&dev->w1_master_entry, &w1_masters);
134 mutex_unlock(&w1_mlock);
136 memset(&msg, 0, sizeof(msg));
137 msg.id.mst.id = dev->id;
138 msg.type = W1_MASTER_ADD;
139 w1_netlink_send(dev, &msg);
143 #if 0 /* Thread cleanup code, not required currently. */
145 set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
146 kthread_stop(dev->thread);
149 w1_destroy_master_attributes(dev);
156 void __w1_remove_master_device(struct w1_master *dev)
158 struct w1_netlink_msg msg;
159 struct w1_slave *sl, *sln;
161 set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
162 kthread_stop(dev->thread);
164 mutex_lock(&w1_mlock);
165 list_del(&dev->w1_master_entry);
166 mutex_unlock(&w1_mlock);
168 mutex_lock(&dev->mutex);
169 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry)
171 w1_destroy_master_attributes(dev);
172 mutex_unlock(&dev->mutex);
173 atomic_dec(&dev->refcnt);
175 while (atomic_read(&dev->refcnt)) {
176 dev_info(&dev->dev, "Waiting for %s to become free: refcnt=%d.\n",
177 dev->name, atomic_read(&dev->refcnt));
179 if (msleep_interruptible(1000))
180 flush_signals(current);
183 memset(&msg, 0, sizeof(msg));
184 msg.id.mst.id = dev->id;
185 msg.type = W1_MASTER_REMOVE;
186 w1_netlink_send(dev, &msg);
191 void w1_remove_master_device(struct w1_bus_master *bm)
193 struct w1_master *dev, *found = NULL;
195 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
196 if (!dev->initialized)
199 if (dev->bus_master->data == bm->data) {
206 printk(KERN_ERR "Device doesn't exist.\n");
210 __w1_remove_master_device(found);
213 EXPORT_SYMBOL(w1_add_master_device);
214 EXPORT_SYMBOL(w1_remove_master_device);