blob: 6840dfebe4d4c82a5abc242a8ee1d66570f100ab [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>
Evgeniy Polyakov674a396c2006-02-20 11:15:37 +030025#include <linux/kthread.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026
27#include "w1.h"
28#include "w1_log.h"
29#include "w1_netlink.h"
Evgeniy Polyakov70d484b2006-04-24 10:46:14 +040030#include "w1_int.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070031
32static u32 w1_ids = 1;
33
Evgeniy Polyakov77859252005-05-20 22:33:25 +040034static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl,
35 struct device_driver *driver,
36 struct device *device)
Linus Torvalds1da177e2005-04-16 15:20:36 -070037{
38 struct w1_master *dev;
39 int err;
40
41 /*
42 * We are in process context(kernel thread), so can sleep.
43 */
Yoann Padioleaudd00cc42007-07-19 01:49:03 -070044 dev = kzalloc(sizeof(struct w1_master) + sizeof(struct w1_bus_master), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070045 if (!dev) {
46 printk(KERN_ERR
47 "Failed to allocate %zd bytes for new w1 device.\n",
48 sizeof(struct w1_master));
49 return NULL;
50 }
51
Linus Torvalds1da177e2005-04-16 15:20:36 -070052
53 dev->bus_master = (struct w1_bus_master *)(dev + 1);
54
Evgeniy Polyakov77859252005-05-20 22:33:25 +040055 dev->owner = THIS_MODULE;
56 dev->max_slave_count = slave_count;
57 dev->slave_count = 0;
58 dev->attempts = 0;
Evgeniy Polyakov77859252005-05-20 22:33:25 +040059 dev->initialized = 0;
60 dev->id = id;
Linus Torvalds1da177e2005-04-16 15:20:36 -070061 dev->slave_ttl = slave_ttl;
Evgeniy Polyakov2a9d0c12005-06-04 01:31:02 +040062 dev->search_count = -1; /* continual scan */
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
64 atomic_set(&dev->refcnt, 2);
65
66 INIT_LIST_HEAD(&dev->slist);
Evgeniy Polyakovabd52a12006-04-03 12:04:27 +040067 mutex_init(&dev->mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 memcpy(&dev->dev, device, sizeof(struct device));
70 snprintf(dev->dev.bus_id, sizeof(dev->dev.bus_id),
71 "w1_bus_master%u", dev->id);
72 snprintf(dev->name, sizeof(dev->name), "w1_bus_master%u", dev->id);
73
74 dev->driver = driver;
75
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 dev->seq = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -070077
78 err = device_register(&dev->dev);
79 if (err) {
80 printk(KERN_ERR "Failed to register master device. err=%d\n", err);
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 memset(dev, 0, sizeof(struct w1_master));
82 kfree(dev);
83 dev = NULL;
84 }
85
86 return dev;
87}
88
Evgeniy Polyakov2c5bfda2006-04-04 20:35:22 +040089static void w1_free_dev(struct w1_master *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -070090{
91 device_unregister(&dev->dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -070092}
93
94int w1_add_master_device(struct w1_bus_master *master)
95{
96 struct w1_master *dev;
97 int retval = 0;
98 struct w1_netlink_msg msg;
99
Evgeniy Polyakovbe57ce22005-06-04 01:21:46 +0400100 /* validate minimum functionality */
101 if (!(master->touch_bit && master->reset_bus) &&
Evgeniy Polyakovc1f858b2007-05-08 00:31:20 -0700102 !(master->write_bit && master->read_bit) &&
103 !(master->write_byte && master->read_byte && master->reset_bus)) {
Evgeniy Polyakov6adf87b2005-06-04 01:29:25 +0400104 printk(KERN_ERR "w1_add_master_device: invalid function set\n");
105 return(-EINVAL);
Evgeniy Polyakovbe57ce22005-06-04 01:21:46 +0400106 }
107
Evgeniy Polyakov7f772ed2005-08-11 13:20:07 +0400108 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 -0700109 if (!dev)
110 return -ENOMEM;
111
Evgeniy Polyakov674a396c2006-02-20 11:15:37 +0300112 dev->thread = kthread_run(&w1_process, dev, "%s", dev->name);
113 if (IS_ERR(dev->thread)) {
114 retval = PTR_ERR(dev->thread);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 dev_err(&dev->dev,
116 "Failed to create new kernel thread. err=%d\n",
Evgeniy Polyakov674a396c2006-02-20 11:15:37 +0300117 retval);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 goto err_out_free_dev;
119 }
120
121 retval = w1_create_master_attributes(dev);
122 if (retval)
123 goto err_out_kill_thread;
124
125 memcpy(dev->bus_master, master, sizeof(struct w1_bus_master));
126
127 dev->initialized = 1;
128
Evgeniy Polyakovabd52a12006-04-03 12:04:27 +0400129 mutex_lock(&w1_mlock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 list_add(&dev->w1_master_entry, &w1_masters);
Evgeniy Polyakovabd52a12006-04-03 12:04:27 +0400131 mutex_unlock(&w1_mlock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132
Evgeniy Polyakov12003372006-03-23 19:11:58 +0300133 memset(&msg, 0, sizeof(msg));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700134 msg.id.mst.id = dev->id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135 msg.type = W1_MASTER_ADD;
136 w1_netlink_send(dev, &msg);
137
138 return 0;
139
140err_out_kill_thread:
Evgeniy Polyakov674a396c2006-02-20 11:15:37 +0300141 kthread_stop(dev->thread);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142err_out_free_dev:
143 w1_free_dev(dev);
144
145 return retval;
146}
147
148void __w1_remove_master_device(struct w1_master *dev)
149{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 struct w1_netlink_msg msg;
151
Evgeniy Polyakov6adf87b2005-06-04 01:29:25 +0400152 set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
Evgeniy Polyakov674a396c2006-02-20 11:15:37 +0300153 kthread_stop(dev->thread);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154
155 while (atomic_read(&dev->refcnt)) {
Evgeniy Polyakov674a396c2006-02-20 11:15:37 +0300156 dev_info(&dev->dev, "Waiting for %s to become free: refcnt=%d.\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 dev->name, atomic_read(&dev->refcnt));
158
159 if (msleep_interruptible(1000))
160 flush_signals(current);
161 }
162
Evgeniy Polyakov12003372006-03-23 19:11:58 +0300163 memset(&msg, 0, sizeof(msg));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 msg.id.mst.id = dev->id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700165 msg.type = W1_MASTER_REMOVE;
166 w1_netlink_send(dev, &msg);
167
168 w1_free_dev(dev);
169}
170
171void w1_remove_master_device(struct w1_bus_master *bm)
172{
Evgeniy Polyakov59d94452007-08-22 14:01:51 -0700173 struct w1_master *dev, *found = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174
Evgeniy Polyakov77859252005-05-20 22:33:25 +0400175 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 if (!dev->initialized)
177 continue;
178
Evgeniy Polyakov59d94452007-08-22 14:01:51 -0700179 if (dev->bus_master->data == bm->data) {
180 found = dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 break;
Evgeniy Polyakov59d94452007-08-22 14:01:51 -0700182 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 }
184
Evgeniy Polyakov59d94452007-08-22 14:01:51 -0700185 if (!found) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 printk(KERN_ERR "Device doesn't exist.\n");
187 return;
188 }
189
Evgeniy Polyakov59d94452007-08-22 14:01:51 -0700190 __w1_remove_master_device(found);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191}
192
193EXPORT_SYMBOL(w1_add_master_device);
194EXPORT_SYMBOL(w1_remove_master_device);