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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>
25
26#include "w1.h"
27#include "w1_log.h"
28#include "w1_netlink.h"
29
30static u32 w1_ids = 1;
31
Evgeniy Polyakov7f772ed2005-08-11 13:20:07 +040032extern struct device_driver w1_master_driver;
Linus Torvalds1da177e2005-04-16 15:20:36 -070033extern struct bus_type w1_bus_type;
Evgeniy Polyakov7f772ed2005-08-11 13:20:07 +040034extern struct device w1_master_device;
Linus Torvalds1da177e2005-04-16 15:20:36 -070035extern int w1_max_slave_count;
36extern int w1_max_slave_ttl;
37extern struct list_head w1_masters;
38extern spinlock_t w1_mlock;
39
40extern int w1_process(void *);
41
Evgeniy Polyakov77859252005-05-20 22:33:25 +040042static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl,
43 struct device_driver *driver,
44 struct device *device)
Linus Torvalds1da177e2005-04-16 15:20:36 -070045{
46 struct w1_master *dev;
47 int err;
48
49 /*
50 * We are in process context(kernel thread), so can sleep.
51 */
52 dev = kmalloc(sizeof(struct w1_master) + sizeof(struct w1_bus_master), GFP_KERNEL);
53 if (!dev) {
54 printk(KERN_ERR
55 "Failed to allocate %zd bytes for new w1 device.\n",
56 sizeof(struct w1_master));
57 return NULL;
58 }
59
60 memset(dev, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master));
61
62 dev->bus_master = (struct w1_bus_master *)(dev + 1);
63
Evgeniy Polyakov77859252005-05-20 22:33:25 +040064 dev->owner = THIS_MODULE;
65 dev->max_slave_count = slave_count;
66 dev->slave_count = 0;
67 dev->attempts = 0;
68 dev->kpid = -1;
69 dev->initialized = 0;
70 dev->id = id;
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 dev->slave_ttl = slave_ttl;
Evgeniy Polyakov2a9d0c12005-06-04 01:31:02 +040072 dev->search_count = -1; /* continual scan */
Linus Torvalds1da177e2005-04-16 15:20:36 -070073
74 atomic_set(&dev->refcnt, 2);
75
76 INIT_LIST_HEAD(&dev->slist);
77 init_MUTEX(&dev->mutex);
78
Linus Torvalds1da177e2005-04-16 15:20:36 -070079 init_completion(&dev->dev_exited);
80
81 memcpy(&dev->dev, device, sizeof(struct device));
82 snprintf(dev->dev.bus_id, sizeof(dev->dev.bus_id),
83 "w1_bus_master%u", dev->id);
84 snprintf(dev->name, sizeof(dev->name), "w1_bus_master%u", dev->id);
85
86 dev->driver = driver;
87
Evgeniy Polyakovad93e262005-08-14 19:24:58 -070088 dev->groups = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 dev->seq = 1;
Evgeniy Polyakov2d833172005-07-27 13:10:11 +040090 dev_init_netlink(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -070091
92 err = device_register(&dev->dev);
93 if (err) {
94 printk(KERN_ERR "Failed to register master device. err=%d\n", err);
Evgeniy Polyakov2d833172005-07-27 13:10:11 +040095
96 dev_fini_netlink(dev);
97
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 memset(dev, 0, sizeof(struct w1_master));
99 kfree(dev);
100 dev = NULL;
101 }
102
103 return dev;
104}
105
Evgeniy Polyakov2d833172005-07-27 13:10:11 +0400106void w1_free_dev(struct w1_master *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107{
108 device_unregister(&dev->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109}
110
111int w1_add_master_device(struct w1_bus_master *master)
112{
113 struct w1_master *dev;
114 int retval = 0;
115 struct w1_netlink_msg msg;
116
Evgeniy Polyakovbe57ce22005-06-04 01:21:46 +0400117 /* validate minimum functionality */
118 if (!(master->touch_bit && master->reset_bus) &&
Evgeniy Polyakov6adf87b2005-06-04 01:29:25 +0400119 !(master->write_bit && master->read_bit)) {
120 printk(KERN_ERR "w1_add_master_device: invalid function set\n");
121 return(-EINVAL);
Evgeniy Polyakovbe57ce22005-06-04 01:21:46 +0400122 }
123
Evgeniy Polyakov7f772ed2005-08-11 13:20:07 +0400124 dev = w1_alloc_dev(w1_ids++, w1_max_slave_count, w1_max_slave_ttl, &w1_master_driver, &w1_master_device);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125 if (!dev)
126 return -ENOMEM;
127
128 dev->kpid = kernel_thread(&w1_process, dev, 0);
129 if (dev->kpid < 0) {
130 dev_err(&dev->dev,
131 "Failed to create new kernel thread. err=%d\n",
132 dev->kpid);
133 retval = dev->kpid;
134 goto err_out_free_dev;
135 }
136
137 retval = w1_create_master_attributes(dev);
138 if (retval)
139 goto err_out_kill_thread;
140
141 memcpy(dev->bus_master, master, sizeof(struct w1_bus_master));
142
143 dev->initialized = 1;
144
145 spin_lock(&w1_mlock);
146 list_add(&dev->w1_master_entry, &w1_masters);
147 spin_unlock(&w1_mlock);
148
149 msg.id.mst.id = dev->id;
150 msg.id.mst.pid = dev->kpid;
151 msg.type = W1_MASTER_ADD;
152 w1_netlink_send(dev, &msg);
153
154 return 0;
155
156err_out_kill_thread:
Evgeniy Polyakov6adf87b2005-06-04 01:29:25 +0400157 set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 if (kill_proc(dev->kpid, SIGTERM, 1))
159 dev_err(&dev->dev,
160 "Failed to send signal to w1 kernel thread %d.\n",
161 dev->kpid);
162 wait_for_completion(&dev->dev_exited);
163
164err_out_free_dev:
165 w1_free_dev(dev);
166
167 return retval;
168}
169
170void __w1_remove_master_device(struct w1_master *dev)
171{
172 int err;
173 struct w1_netlink_msg msg;
174
Evgeniy Polyakov6adf87b2005-06-04 01:29:25 +0400175 set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 err = kill_proc(dev->kpid, SIGTERM, 1);
177 if (err)
178 dev_err(&dev->dev,
179 "%s: Failed to send signal to w1 kernel thread %d.\n",
180 __func__, dev->kpid);
181
182 while (atomic_read(&dev->refcnt)) {
Evgeniy Polyakov3aca6922005-08-11 17:27:50 +0400183 dev_dbg(&dev->dev, "Waiting for %s to become free: refcnt=%d.\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 dev->name, atomic_read(&dev->refcnt));
185
186 if (msleep_interruptible(1000))
187 flush_signals(current);
188 }
189
190 msg.id.mst.id = dev->id;
191 msg.id.mst.pid = dev->kpid;
192 msg.type = W1_MASTER_REMOVE;
193 w1_netlink_send(dev, &msg);
194
195 w1_free_dev(dev);
196}
197
198void w1_remove_master_device(struct w1_bus_master *bm)
199{
200 struct w1_master *dev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700201
Evgeniy Polyakov77859252005-05-20 22:33:25 +0400202 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700203 if (!dev->initialized)
204 continue;
205
206 if (dev->bus_master->data == bm->data)
207 break;
208 }
209
210 if (!dev) {
211 printk(KERN_ERR "Device doesn't exist.\n");
212 return;
213 }
214
215 __w1_remove_master_device(dev);
216}
217
218EXPORT_SYMBOL(w1_add_master_device);
219EXPORT_SYMBOL(w1_remove_master_device);
Harald Welte4fdb3bb2005-08-09 19:40:55 -0700220
221MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_W1);