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>
25 #include <linux/kthread.h>
29 #include "w1_netlink.h"
32 static u32 w1_ids
= 1;
34 static struct w1_master
* w1_alloc_dev(u32 id
, int slave_count
, int slave_ttl
,
35 struct device_driver
*driver
,
36 struct device
*device
)
38 struct w1_master
*dev
;
42 * We are in process context(kernel thread), so can sleep.
44 dev
= kzalloc(sizeof(struct w1_master
) + sizeof(struct w1_bus_master
), GFP_KERNEL
);
47 "Failed to allocate %zd bytes for new w1 device.\n",
48 sizeof(struct w1_master
));
53 dev
->bus_master
= (struct w1_bus_master
*)(dev
+ 1);
55 dev
->owner
= THIS_MODULE
;
56 dev
->max_slave_count
= slave_count
;
61 dev
->slave_ttl
= slave_ttl
;
62 dev
->search_count
= -1; /* continual scan */
64 /* 1 for w1_process to decrement
65 * 1 for __w1_remove_master_device to decrement
67 atomic_set(&dev
->refcnt
, 2);
69 INIT_LIST_HEAD(&dev
->slist
);
70 mutex_init(&dev
->mutex
);
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 err
= device_register(&dev
->dev
);
83 printk(KERN_ERR
"Failed to register master device. err=%d\n", err
);
84 memset(dev
, 0, sizeof(struct w1_master
));
92 static void w1_free_dev(struct w1_master
*dev
)
94 device_unregister(&dev
->dev
);
97 int w1_add_master_device(struct w1_bus_master
*master
)
99 struct w1_master
*dev
;
101 struct w1_netlink_msg msg
;
103 /* validate minimum functionality */
104 if (!(master
->touch_bit
&& master
->reset_bus
) &&
105 !(master
->write_bit
&& master
->read_bit
) &&
106 !(master
->write_byte
&& master
->read_byte
&& master
->reset_bus
)) {
107 printk(KERN_ERR
"w1_add_master_device: invalid function set\n");
111 dev
= w1_alloc_dev(w1_ids
++, w1_max_slave_count
, w1_max_slave_ttl
, &w1_master_driver
, &w1_master_device
);
115 retval
= w1_create_master_attributes(dev
);
117 goto err_out_free_dev
;
119 memcpy(dev
->bus_master
, master
, sizeof(struct w1_bus_master
));
121 dev
->initialized
= 1;
123 dev
->thread
= kthread_run(&w1_process
, dev
, "%s", dev
->name
);
124 if (IS_ERR(dev
->thread
)) {
125 retval
= PTR_ERR(dev
->thread
);
127 "Failed to create new kernel thread. err=%d\n",
129 goto err_out_rm_attr
;
132 mutex_lock(&w1_mlock
);
133 list_add(&dev
->w1_master_entry
, &w1_masters
);
134 mutex_unlock(&w1_mlock
);
136 memset(&msg
, 0, sizeof(msg
));
137 msg
.id
.mst
.id
= dev
->id
;
138 msg
.type
= W1_MASTER_ADD
;
139 w1_netlink_send(dev
, &msg
);
143 #if 0 /* Thread cleanup code, not required currently. */
145 kthread_stop(dev
->thread
);
148 w1_destroy_master_attributes(dev
);
155 void __w1_remove_master_device(struct w1_master
*dev
)
157 struct w1_netlink_msg msg
;
158 struct w1_slave
*sl
, *sln
;
160 kthread_stop(dev
->thread
);
162 mutex_lock(&w1_mlock
);
163 list_del(&dev
->w1_master_entry
);
164 mutex_unlock(&w1_mlock
);
166 mutex_lock(&dev
->mutex
);
167 list_for_each_entry_safe(sl
, sln
, &dev
->slist
, w1_slave_entry
)
169 w1_destroy_master_attributes(dev
);
170 mutex_unlock(&dev
->mutex
);
171 atomic_dec(&dev
->refcnt
);
173 while (atomic_read(&dev
->refcnt
)) {
174 dev_info(&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 memset(&msg
, 0, sizeof(msg
));
182 msg
.id
.mst
.id
= dev
->id
;
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
, *found
= NULL
;
193 list_for_each_entry(dev
, &w1_masters
, w1_master_entry
) {
194 if (!dev
->initialized
)
197 if (dev
->bus_master
->data
== bm
->data
) {
204 printk(KERN_ERR
"Device doesn't exist.\n");
208 __w1_remove_master_device(found
);
211 EXPORT_SYMBOL(w1_add_master_device
);
212 EXPORT_SYMBOL(w1_remove_master_device
);
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