blob: 2a538d012194a06b71cf28b58fae76dbeb5d4251 [file] [log] [blame]
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
32extern struct device_driver w1_driver;
33extern struct bus_type w1_bus_type;
34extern struct device w1_device;
35extern 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
79 init_completion(&dev->dev_released);
80 init_completion(&dev->dev_exited);
81
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);
86
87 dev->driver = driver;
88
Evgeniy Polyakovad93e262005-08-14 19:24:58 -070089 dev->groups = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -070090 dev->seq = 1;
Evgeniy Polyakov2d833172005-07-27 13:10:11 +040091 dev_init_netlink(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -070092
93 err = device_register(&dev->dev);
94 if (err) {
95 printk(KERN_ERR "Failed to register master device. err=%d\n", err);
Evgeniy Polyakov2d833172005-07-27 13:10:11 +040096
97 dev_fini_netlink(dev);
98
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 memset(dev, 0, sizeof(struct w1_master));
100 kfree(dev);
101 dev = NULL;
102 }
103
104 return dev;
105}
106
Evgeniy Polyakov2d833172005-07-27 13:10:11 +0400107void w1_free_dev(struct w1_master *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108{
109 device_unregister(&dev->dev);
Evgeniy Polyakov2d833172005-07-27 13:10:11 +0400110 dev_fini_netlink(dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111 memset(dev, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master));
112 kfree(dev);
113}
114
115int w1_add_master_device(struct w1_bus_master *master)
116{
117 struct w1_master *dev;
118 int retval = 0;
119 struct w1_netlink_msg msg;
120
Evgeniy Polyakovbe57ce22005-06-04 01:21:46 +0400121 /* validate minimum functionality */
122 if (!(master->touch_bit && master->reset_bus) &&
Evgeniy Polyakov6adf87b2005-06-04 01:29:25 +0400123 !(master->write_bit && master->read_bit)) {
124 printk(KERN_ERR "w1_add_master_device: invalid function set\n");
125 return(-EINVAL);
Evgeniy Polyakovbe57ce22005-06-04 01:21:46 +0400126 }
127
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 dev = w1_alloc_dev(w1_ids++, w1_max_slave_count, w1_max_slave_ttl, &w1_driver, &w1_device);
129 if (!dev)
130 return -ENOMEM;
131
132 dev->kpid = kernel_thread(&w1_process, dev, 0);
133 if (dev->kpid < 0) {
134 dev_err(&dev->dev,
135 "Failed to create new kernel thread. err=%d\n",
136 dev->kpid);
137 retval = dev->kpid;
138 goto err_out_free_dev;
139 }
140
141 retval = w1_create_master_attributes(dev);
142 if (retval)
143 goto err_out_kill_thread;
144
145 memcpy(dev->bus_master, master, sizeof(struct w1_bus_master));
146
147 dev->initialized = 1;
148
149 spin_lock(&w1_mlock);
150 list_add(&dev->w1_master_entry, &w1_masters);
151 spin_unlock(&w1_mlock);
152
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);
157
158 return 0;
159
160err_out_kill_thread:
Evgeniy Polyakov6adf87b2005-06-04 01:29:25 +0400161 set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 if (kill_proc(dev->kpid, SIGTERM, 1))
163 dev_err(&dev->dev,
164 "Failed to send signal to w1 kernel thread %d.\n",
165 dev->kpid);
166 wait_for_completion(&dev->dev_exited);
167
168err_out_free_dev:
169 w1_free_dev(dev);
170
171 return retval;
172}
173
174void __w1_remove_master_device(struct w1_master *dev)
175{
176 int err;
177 struct w1_netlink_msg msg;
178
Evgeniy Polyakov6adf87b2005-06-04 01:29:25 +0400179 set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180 err = kill_proc(dev->kpid, SIGTERM, 1);
181 if (err)
182 dev_err(&dev->dev,
183 "%s: Failed to send signal to w1 kernel thread %d.\n",
184 __func__, dev->kpid);
185
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));
189
190 if (msleep_interruptible(1000))
191 flush_signals(current);
192 }
193
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);
198
199 w1_free_dev(dev);
200}
201
202void w1_remove_master_device(struct w1_bus_master *bm)
203{
204 struct w1_master *dev = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205
Evgeniy Polyakov77859252005-05-20 22:33:25 +0400206 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 if (!dev->initialized)
208 continue;
209
210 if (dev->bus_master->data == bm->data)
211 break;
212 }
213
214 if (!dev) {
215 printk(KERN_ERR "Device doesn't exist.\n");
216 return;
217 }
218
219 __w1_remove_master_device(dev);
220}
221
222EXPORT_SYMBOL(w1_add_master_device);
223EXPORT_SYMBOL(w1_remove_master_device);
Harald Welte4fdb3bb2005-08-09 19:40:55 -0700224
225MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_W1);