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>
28 #include "w1_netlink.h"
31 static u32 w1_ids = 1;
33 static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl,
34 struct device_driver *driver,
35 struct device *device)
37 struct w1_master *dev;
41 * We are in process context(kernel thread), so can sleep.
43 dev = kmalloc(sizeof(struct w1_master) + sizeof(struct w1_bus_master), GFP_KERNEL);
46 "Failed to allocate %zd bytes for new w1 device.\n",
47 sizeof(struct w1_master));
51 memset(dev, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master));
53 dev->bus_master = (struct w1_bus_master *)(dev + 1);
55 dev->owner = THIS_MODULE;
56 dev->max_slave_count = slave_count;
62 dev->slave_ttl = slave_ttl;
63 dev->search_count = -1; /* continual scan */
65 atomic_set(&dev->refcnt, 2);
67 INIT_LIST_HEAD(&dev->slist);
68 init_MUTEX(&dev->mutex);
70 init_completion(&dev->dev_exited);
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 dev_init_netlink(dev);
83 err = device_register(&dev->dev);
85 printk(KERN_ERR "Failed to register master device. err=%d\n", err);
87 dev_fini_netlink(dev);
89 memset(dev, 0, sizeof(struct w1_master));
97 static void w1_free_dev(struct w1_master *dev)
99 device_unregister(&dev->dev);
102 int w1_add_master_device(struct w1_bus_master *master)
104 struct w1_master *dev;
106 struct w1_netlink_msg msg;
108 /* validate minimum functionality */
109 if (!(master->touch_bit && master->reset_bus) &&
110 !(master->write_bit && master->read_bit)) {
111 printk(KERN_ERR "w1_add_master_device: invalid function set\n");
115 dev = w1_alloc_dev(w1_ids++, w1_max_slave_count, w1_max_slave_ttl, &w1_master_driver, &w1_master_device);
119 dev->kpid = kernel_thread(&w1_process, dev, 0);
122 "Failed to create new kernel thread. err=%d\n",
125 goto err_out_free_dev;
128 retval = w1_create_master_attributes(dev);
130 goto err_out_kill_thread;
132 memcpy(dev->bus_master, master, sizeof(struct w1_bus_master));
134 dev->initialized = 1;
136 spin_lock(&w1_mlock);
137 list_add(&dev->w1_master_entry, &w1_masters);
138 spin_unlock(&w1_mlock);
140 msg.id.mst.id = dev->id;
141 msg.id.mst.pid = dev->kpid;
142 msg.type = W1_MASTER_ADD;
143 w1_netlink_send(dev, &msg);
148 set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
149 if (kill_proc(dev->kpid, SIGTERM, 1))
151 "Failed to send signal to w1 kernel thread %d.\n",
153 wait_for_completion(&dev->dev_exited);
161 void __w1_remove_master_device(struct w1_master *dev)
164 struct w1_netlink_msg msg;
166 set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
167 err = kill_proc(dev->kpid, SIGTERM, 1);
170 "%s: Failed to send signal to w1 kernel thread %d.\n",
171 __func__, dev->kpid);
173 while (atomic_read(&dev->refcnt)) {
174 dev_dbg(&dev->dev, "Waiting for %s to become free: refcnt=%d.\n",
175 dev->name, atomic_read(&dev->refcnt));
177 if (msleep_interruptible(1000))
178 flush_signals(current);
181 msg.id.mst.id = dev->id;
182 msg.id.mst.pid = dev->kpid;
183 msg.type = W1_MASTER_REMOVE;
184 w1_netlink_send(dev, &msg);
189 void w1_remove_master_device(struct w1_bus_master *bm)
191 struct w1_master *dev = NULL;
193 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
194 if (!dev->initialized)
197 if (dev->bus_master->data == bm->data)
202 printk(KERN_ERR "Device doesn't exist.\n");
206 __w1_remove_master_device(dev);
209 EXPORT_SYMBOL(w1_add_master_device);
210 EXPORT_SYMBOL(w1_remove_master_device);