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"
30 static u32 w1_ids = 1;
32 extern struct device_driver w1_driver;
33 extern struct bus_type w1_bus_type;
34 extern struct device w1_device;
35 extern int w1_max_slave_count;
36 extern int w1_max_slave_ttl;
37 extern struct list_head w1_masters;
38 extern spinlock_t w1_mlock;
40 extern int w1_process(void *);
42 static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl,
43 struct device_driver *driver,
44 struct device *device)
46 struct w1_master *dev;
50 * We are in process context(kernel thread), so can sleep.
52 dev = kmalloc(sizeof(struct w1_master) + sizeof(struct w1_bus_master), GFP_KERNEL);
55 "Failed to allocate %zd bytes for new w1 device.\n",
56 sizeof(struct w1_master));
60 memset(dev, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master));
62 dev->bus_master = (struct w1_bus_master *)(dev + 1);
64 dev->owner = THIS_MODULE;
65 dev->max_slave_count = slave_count;
71 dev->slave_ttl = slave_ttl;
72 dev->search_count = -1; /* continual scan */
74 atomic_set(&dev->refcnt, 2);
76 INIT_LIST_HEAD(&dev->slist);
77 init_MUTEX(&dev->mutex);
79 init_completion(&dev->dev_released);
80 init_completion(&dev->dev_exited);
82 memcpy(&dev->dev, device, sizeof(struct device));
83 snprintf(dev->dev.bus_id, sizeof(dev->dev.bus_id),
84 "w1_bus_master%u", dev->id);
85 snprintf(dev->name, sizeof(dev->name), "w1_bus_master%u", dev->id);
91 dev_init_netlink(dev);
93 err = device_register(&dev->dev);
95 printk(KERN_ERR "Failed to register master device. err=%d\n", err);
97 dev_fini_netlink(dev);
99 memset(dev, 0, sizeof(struct w1_master));
107 void w1_free_dev(struct w1_master *dev)
109 device_unregister(&dev->dev);
110 dev_fini_netlink(dev);
111 memset(dev, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master));
115 int w1_add_master_device(struct w1_bus_master *master)
117 struct w1_master *dev;
119 struct w1_netlink_msg msg;
121 /* validate minimum functionality */
122 if (!(master->touch_bit && master->reset_bus) &&
123 !(master->write_bit && master->read_bit)) {
124 printk(KERN_ERR "w1_add_master_device: invalid function set\n");
128 dev = w1_alloc_dev(w1_ids++, w1_max_slave_count, w1_max_slave_ttl, &w1_driver, &w1_device);
132 dev->kpid = kernel_thread(&w1_process, dev, 0);
135 "Failed to create new kernel thread. err=%d\n",
138 goto err_out_free_dev;
141 retval = w1_create_master_attributes(dev);
143 goto err_out_kill_thread;
145 memcpy(dev->bus_master, master, sizeof(struct w1_bus_master));
147 dev->initialized = 1;
149 spin_lock(&w1_mlock);
150 list_add(&dev->w1_master_entry, &w1_masters);
151 spin_unlock(&w1_mlock);
153 msg.id.mst.id = dev->id;
154 msg.id.mst.pid = dev->kpid;
155 msg.type = W1_MASTER_ADD;
156 w1_netlink_send(dev, &msg);
161 set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
162 if (kill_proc(dev->kpid, SIGTERM, 1))
164 "Failed to send signal to w1 kernel thread %d.\n",
166 wait_for_completion(&dev->dev_exited);
174 void __w1_remove_master_device(struct w1_master *dev)
177 struct w1_netlink_msg msg;
179 set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
180 err = kill_proc(dev->kpid, SIGTERM, 1);
183 "%s: Failed to send signal to w1 kernel thread %d.\n",
184 __func__, dev->kpid);
186 while (atomic_read(&dev->refcnt)) {
187 printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n",
188 dev->name, atomic_read(&dev->refcnt));
190 if (msleep_interruptible(1000))
191 flush_signals(current);
194 msg.id.mst.id = dev->id;
195 msg.id.mst.pid = dev->kpid;
196 msg.type = W1_MASTER_REMOVE;
197 w1_netlink_send(dev, &msg);
202 void w1_remove_master_device(struct w1_bus_master *bm)
204 struct w1_master *dev = NULL;
206 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
207 if (!dev->initialized)
210 if (dev->bus_master->data == bm->data)
215 printk(KERN_ERR "Device doesn't exist.\n");
219 __w1_remove_master_device(dev);
222 EXPORT_SYMBOL(w1_add_master_device);
223 EXPORT_SYMBOL(w1_remove_master_device);
225 MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_W1);