4 * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
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>
26 #include <linux/slab.h>
27 #include <linux/export.h>
28 #include <linux/moduleparam.h>
32 #include "w1_netlink.h"
35 static int w1_search_count
= -1; /* Default is continual scan */
36 module_param_named(search_count
, w1_search_count
, int, 0);
38 static int w1_enable_pullup
= 1;
39 module_param_named(enable_pullup
, w1_enable_pullup
, int, 0);
41 static struct w1_master
* w1_alloc_dev(u32 id
, int slave_count
, int slave_ttl
,
42 struct device_driver
*driver
,
43 struct device
*device
)
45 struct w1_master
*dev
;
49 * We are in process context(kernel thread), so can sleep.
51 dev
= kzalloc(sizeof(struct w1_master
) + sizeof(struct w1_bus_master
), GFP_KERNEL
);
54 "Failed to allocate %zd bytes for new w1 device.\n",
55 sizeof(struct w1_master
));
60 dev
->bus_master
= (struct w1_bus_master
*)(dev
+ 1);
62 dev
->owner
= THIS_MODULE
;
63 dev
->max_slave_count
= slave_count
;
68 dev
->slave_ttl
= slave_ttl
;
69 dev
->search_count
= w1_search_count
;
70 dev
->enable_pullup
= w1_enable_pullup
;
72 /* 1 for w1_process to decrement
73 * 1 for __w1_remove_master_device to decrement
75 atomic_set(&dev
->refcnt
, 2);
77 INIT_LIST_HEAD(&dev
->slist
);
78 mutex_init(&dev
->mutex
);
79 mutex_init(&dev
->bus_mutex
);
81 memcpy(&dev
->dev
, device
, sizeof(struct device
));
82 dev_set_name(&dev
->dev
, "w1_bus_master%u", dev
->id
);
83 snprintf(dev
->name
, sizeof(dev
->name
), "w1_bus_master%u", dev
->id
);
84 dev
->dev
.init_name
= dev
->name
;
90 err
= device_register(&dev
->dev
);
92 printk(KERN_ERR
"Failed to register master device. err=%d\n", err
);
93 memset(dev
, 0, sizeof(struct w1_master
));
101 static void w1_free_dev(struct w1_master
*dev
)
103 device_unregister(&dev
->dev
);
106 int w1_add_master_device(struct w1_bus_master
*master
)
108 struct w1_master
*dev
, *entry
;
110 struct w1_netlink_msg msg
;
113 /* validate minimum functionality */
114 if (!(master
->touch_bit
&& master
->reset_bus
) &&
115 !(master
->write_bit
&& master
->read_bit
) &&
116 !(master
->write_byte
&& master
->read_byte
&& master
->reset_bus
)) {
117 printk(KERN_ERR
"w1_add_master_device: invalid function set\n");
120 /* While it would be electrically possible to make a device that
121 * generated a strong pullup in bit bang mode, only hardware that
122 * controls 1-wire time frames are even expected to support a strong
123 * pullup. w1_io.c would need to support calling set_pullup before
124 * the last write_bit operation of a w1_write_8 which it currently
127 if (!master
->write_byte
&& !master
->touch_bit
&& master
->set_pullup
) {
128 printk(KERN_ERR
"w1_add_master_device: set_pullup requires "
129 "write_byte or touch_bit, disabling\n");
130 master
->set_pullup
= NULL
;
133 /* Lock until the device is added (or not) to w1_masters. */
134 mutex_lock(&w1_mlock
);
135 /* Search for the first available id (starting at 1). */
140 list_for_each_entry(entry
, &w1_masters
, w1_master_entry
) {
141 if (entry
->id
== id
) {
148 dev
= w1_alloc_dev(id
, w1_max_slave_count
, w1_max_slave_ttl
,
149 &w1_master_driver
, &w1_master_device
);
151 mutex_unlock(&w1_mlock
);
155 retval
= w1_create_master_attributes(dev
);
157 mutex_unlock(&w1_mlock
);
158 goto err_out_free_dev
;
161 memcpy(dev
->bus_master
, master
, sizeof(struct w1_bus_master
));
163 dev
->initialized
= 1;
165 dev
->thread
= kthread_run(&w1_process
, dev
, "%s", dev
->name
);
166 if (IS_ERR(dev
->thread
)) {
167 retval
= PTR_ERR(dev
->thread
);
169 "Failed to create new kernel thread. err=%d\n",
171 mutex_unlock(&w1_mlock
);
172 goto err_out_rm_attr
;
175 list_add(&dev
->w1_master_entry
, &w1_masters
);
176 mutex_unlock(&w1_mlock
);
178 memset(&msg
, 0, sizeof(msg
));
179 msg
.id
.mst
.id
= dev
->id
;
180 msg
.type
= W1_MASTER_ADD
;
181 w1_netlink_send(dev
, &msg
);
185 #if 0 /* Thread cleanup code, not required currently. */
187 kthread_stop(dev
->thread
);
190 w1_destroy_master_attributes(dev
);
197 void __w1_remove_master_device(struct w1_master
*dev
)
199 struct w1_netlink_msg msg
;
200 struct w1_slave
*sl
, *sln
;
202 kthread_stop(dev
->thread
);
204 mutex_lock(&w1_mlock
);
205 list_del(&dev
->w1_master_entry
);
206 mutex_unlock(&w1_mlock
);
208 mutex_lock(&dev
->mutex
);
209 list_for_each_entry_safe(sl
, sln
, &dev
->slist
, w1_slave_entry
)
211 w1_destroy_master_attributes(dev
);
212 mutex_unlock(&dev
->mutex
);
213 atomic_dec(&dev
->refcnt
);
215 while (atomic_read(&dev
->refcnt
)) {
216 dev_info(&dev
->dev
, "Waiting for %s to become free: refcnt=%d.\n",
217 dev
->name
, atomic_read(&dev
->refcnt
));
219 if (msleep_interruptible(1000))
220 flush_signals(current
);
223 memset(&msg
, 0, sizeof(msg
));
224 msg
.id
.mst
.id
= dev
->id
;
225 msg
.type
= W1_MASTER_REMOVE
;
226 w1_netlink_send(dev
, &msg
);
231 void w1_remove_master_device(struct w1_bus_master
*bm
)
233 struct w1_master
*dev
, *found
= NULL
;
235 list_for_each_entry(dev
, &w1_masters
, w1_master_entry
) {
236 if (!dev
->initialized
)
239 if (dev
->bus_master
->data
== bm
->data
) {
246 printk(KERN_ERR
"Device doesn't exist.\n");
250 __w1_remove_master_device(found
);
253 EXPORT_SYMBOL(w1_add_master_device
);
254 EXPORT_SYMBOL(w1_remove_master_device
);
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