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Commit | Line | Data |
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1da177e4 | 1 | /* |
7785925d | 2 | * w1_int.c |
1da177e4 | 3 | * |
a8018766 | 4 | * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net> |
7785925d | 5 | * |
1da177e4 LT |
6 | * |
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> | |
674a396c | 25 | #include <linux/kthread.h> |
5a0e3ad6 | 26 | #include <linux/slab.h> |
9623932c | 27 | #include <linux/export.h> |
4d184129 | 28 | #include <linux/moduleparam.h> |
1da177e4 LT |
29 | |
30 | #include "w1.h" | |
31 | #include "w1_log.h" | |
32 | #include "w1_netlink.h" | |
70d484bf | 33 | #include "w1_int.h" |
1da177e4 | 34 | |
9141f57c DF |
35 | static int w1_search_count = -1; /* Default is continual scan */ |
36 | module_param_named(search_count, w1_search_count, int, 0); | |
1da177e4 | 37 | |
6a158c0d DF |
38 | static int w1_enable_pullup = 1; |
39 | module_param_named(enable_pullup, w1_enable_pullup, int, 0); | |
40 | ||
7785925d EP |
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) | |
1da177e4 LT |
44 | { |
45 | struct w1_master *dev; | |
46 | int err; | |
47 | ||
48 | /* | |
49 | * We are in process context(kernel thread), so can sleep. | |
50 | */ | |
dd00cc48 | 51 | dev = kzalloc(sizeof(struct w1_master) + sizeof(struct w1_bus_master), GFP_KERNEL); |
1da177e4 LT |
52 | if (!dev) { |
53 | printk(KERN_ERR | |
54 | "Failed to allocate %zd bytes for new w1 device.\n", | |
55 | sizeof(struct w1_master)); | |
56 | return NULL; | |
57 | } | |
58 | ||
1da177e4 LT |
59 | |
60 | dev->bus_master = (struct w1_bus_master *)(dev + 1); | |
61 | ||
7785925d EP |
62 | dev->owner = THIS_MODULE; |
63 | dev->max_slave_count = slave_count; | |
64 | dev->slave_count = 0; | |
65 | dev->attempts = 0; | |
7785925d EP |
66 | dev->initialized = 0; |
67 | dev->id = id; | |
1da177e4 | 68 | dev->slave_ttl = slave_ttl; |
9141f57c | 69 | dev->search_count = w1_search_count; |
6a158c0d | 70 | dev->enable_pullup = w1_enable_pullup; |
1da177e4 | 71 | |
01e14d6d DF |
72 | /* 1 for w1_process to decrement |
73 | * 1 for __w1_remove_master_device to decrement | |
74 | */ | |
1da177e4 LT |
75 | atomic_set(&dev->refcnt, 2); |
76 | ||
77 | INIT_LIST_HEAD(&dev->slist); | |
9fcbbac5 | 78 | INIT_LIST_HEAD(&dev->async_list); |
abd52a13 | 79 | mutex_init(&dev->mutex); |
b02f8bed | 80 | mutex_init(&dev->bus_mutex); |
9fcbbac5 | 81 | mutex_init(&dev->list_mutex); |
1da177e4 | 82 | |
1da177e4 | 83 | memcpy(&dev->dev, device, sizeof(struct device)); |
40f91de6 | 84 | dev_set_name(&dev->dev, "w1_bus_master%u", dev->id); |
1da177e4 | 85 | snprintf(dev->name, sizeof(dev->name), "w1_bus_master%u", dev->id); |
68a436ae | 86 | dev->dev.init_name = dev->name; |
1da177e4 LT |
87 | |
88 | dev->driver = driver; | |
89 | ||
1da177e4 | 90 | dev->seq = 1; |
1da177e4 LT |
91 | |
92 | err = device_register(&dev->dev); | |
93 | if (err) { | |
94 | printk(KERN_ERR "Failed to register master device. err=%d\n", err); | |
1da177e4 LT |
95 | memset(dev, 0, sizeof(struct w1_master)); |
96 | kfree(dev); | |
97 | dev = NULL; | |
98 | } | |
99 | ||
100 | return dev; | |
101 | } | |
102 | ||
2c5bfdac | 103 | static void w1_free_dev(struct w1_master *dev) |
1da177e4 LT |
104 | { |
105 | device_unregister(&dev->dev); | |
1da177e4 LT |
106 | } |
107 | ||
b3be177a DF |
108 | /** |
109 | * w1_add_master_device() - registers a new master device | |
110 | * @master: master bus device to register | |
111 | */ | |
1da177e4 LT |
112 | int w1_add_master_device(struct w1_bus_master *master) |
113 | { | |
af00a2d5 | 114 | struct w1_master *dev, *entry; |
1da177e4 LT |
115 | int retval = 0; |
116 | struct w1_netlink_msg msg; | |
af00a2d5 | 117 | int id, found; |
1da177e4 | 118 | |
be57ce26 EP |
119 | /* validate minimum functionality */ |
120 | if (!(master->touch_bit && master->reset_bus) && | |
c1f858b7 EP |
121 | !(master->write_bit && master->read_bit) && |
122 | !(master->write_byte && master->read_byte && master->reset_bus)) { | |
6adf87bd EP |
123 | printk(KERN_ERR "w1_add_master_device: invalid function set\n"); |
124 | return(-EINVAL); | |
be57ce26 EP |
125 | } |
126 | ||
af00a2d5 DF |
127 | /* Lock until the device is added (or not) to w1_masters. */ |
128 | mutex_lock(&w1_mlock); | |
129 | /* Search for the first available id (starting at 1). */ | |
130 | id = 0; | |
131 | do { | |
132 | ++id; | |
133 | found = 0; | |
134 | list_for_each_entry(entry, &w1_masters, w1_master_entry) { | |
135 | if (entry->id == id) { | |
136 | found = 1; | |
137 | break; | |
138 | } | |
139 | } | |
140 | } while (found); | |
141 | ||
142 | dev = w1_alloc_dev(id, w1_max_slave_count, w1_max_slave_ttl, | |
143 | &w1_master_driver, &w1_master_device); | |
144 | if (!dev) { | |
145 | mutex_unlock(&w1_mlock); | |
1da177e4 | 146 | return -ENOMEM; |
af00a2d5 | 147 | } |
1da177e4 | 148 | |
01e14d6d | 149 | retval = w1_create_master_attributes(dev); |
af00a2d5 DF |
150 | if (retval) { |
151 | mutex_unlock(&w1_mlock); | |
01e14d6d | 152 | goto err_out_free_dev; |
af00a2d5 | 153 | } |
01e14d6d DF |
154 | |
155 | memcpy(dev->bus_master, master, sizeof(struct w1_bus_master)); | |
156 | ||
157 | dev->initialized = 1; | |
158 | ||
674a396c EP |
159 | dev->thread = kthread_run(&w1_process, dev, "%s", dev->name); |
160 | if (IS_ERR(dev->thread)) { | |
161 | retval = PTR_ERR(dev->thread); | |
1da177e4 LT |
162 | dev_err(&dev->dev, |
163 | "Failed to create new kernel thread. err=%d\n", | |
674a396c | 164 | retval); |
af00a2d5 | 165 | mutex_unlock(&w1_mlock); |
01e14d6d | 166 | goto err_out_rm_attr; |
1da177e4 LT |
167 | } |
168 | ||
1da177e4 | 169 | list_add(&dev->w1_master_entry, &w1_masters); |
abd52a13 | 170 | mutex_unlock(&w1_mlock); |
1da177e4 | 171 | |
12003375 | 172 | memset(&msg, 0, sizeof(msg)); |
1da177e4 | 173 | msg.id.mst.id = dev->id; |
1da177e4 LT |
174 | msg.type = W1_MASTER_ADD; |
175 | w1_netlink_send(dev, &msg); | |
176 | ||
177 | return 0; | |
178 | ||
01e14d6d | 179 | #if 0 /* Thread cleanup code, not required currently. */ |
1da177e4 | 180 | err_out_kill_thread: |
42105698 | 181 | set_bit(W1_ABORT_SEARCH, &dev->flags); |
674a396c | 182 | kthread_stop(dev->thread); |
01e14d6d DF |
183 | #endif |
184 | err_out_rm_attr: | |
185 | w1_destroy_master_attributes(dev); | |
1da177e4 LT |
186 | err_out_free_dev: |
187 | w1_free_dev(dev); | |
188 | ||
189 | return retval; | |
190 | } | |
191 | ||
192 | void __w1_remove_master_device(struct w1_master *dev) | |
193 | { | |
1da177e4 | 194 | struct w1_netlink_msg msg; |
c30c9b15 | 195 | struct w1_slave *sl, *sln; |
1da177e4 | 196 | |
c30c9b15 DF |
197 | mutex_lock(&w1_mlock); |
198 | list_del(&dev->w1_master_entry); | |
199 | mutex_unlock(&w1_mlock); | |
200 | ||
9fcbbac5 DF |
201 | set_bit(W1_ABORT_SEARCH, &dev->flags); |
202 | kthread_stop(dev->thread); | |
203 | ||
c30c9b15 | 204 | mutex_lock(&dev->mutex); |
9fcbbac5 DF |
205 | mutex_lock(&dev->list_mutex); |
206 | list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) { | |
207 | mutex_unlock(&dev->list_mutex); | |
c30c9b15 | 208 | w1_slave_detach(sl); |
9fcbbac5 DF |
209 | mutex_lock(&dev->list_mutex); |
210 | } | |
c30c9b15 | 211 | w1_destroy_master_attributes(dev); |
9fcbbac5 | 212 | mutex_unlock(&dev->list_mutex); |
c30c9b15 DF |
213 | mutex_unlock(&dev->mutex); |
214 | atomic_dec(&dev->refcnt); | |
215 | ||
1da177e4 | 216 | while (atomic_read(&dev->refcnt)) { |
674a396c | 217 | dev_info(&dev->dev, "Waiting for %s to become free: refcnt=%d.\n", |
1da177e4 LT |
218 | dev->name, atomic_read(&dev->refcnt)); |
219 | ||
220 | if (msleep_interruptible(1000)) | |
221 | flush_signals(current); | |
9fcbbac5 | 222 | w1_process_callbacks(dev); |
1da177e4 | 223 | } |
9fcbbac5 | 224 | w1_process_callbacks(dev); |
1da177e4 | 225 | |
12003375 | 226 | memset(&msg, 0, sizeof(msg)); |
1da177e4 | 227 | msg.id.mst.id = dev->id; |
1da177e4 LT |
228 | msg.type = W1_MASTER_REMOVE; |
229 | w1_netlink_send(dev, &msg); | |
230 | ||
231 | w1_free_dev(dev); | |
232 | } | |
233 | ||
b3be177a DF |
234 | /** |
235 | * w1_remove_master_device() - unregister a master device | |
236 | * @bm: master bus device to remove | |
237 | */ | |
1da177e4 LT |
238 | void w1_remove_master_device(struct w1_bus_master *bm) |
239 | { | |
59d9445e | 240 | struct w1_master *dev, *found = NULL; |
1da177e4 | 241 | |
7785925d | 242 | list_for_each_entry(dev, &w1_masters, w1_master_entry) { |
1da177e4 LT |
243 | if (!dev->initialized) |
244 | continue; | |
245 | ||
59d9445e EP |
246 | if (dev->bus_master->data == bm->data) { |
247 | found = dev; | |
1da177e4 | 248 | break; |
59d9445e | 249 | } |
1da177e4 LT |
250 | } |
251 | ||
59d9445e | 252 | if (!found) { |
1da177e4 LT |
253 | printk(KERN_ERR "Device doesn't exist.\n"); |
254 | return; | |
255 | } | |
256 | ||
59d9445e | 257 | __w1_remove_master_device(found); |
1da177e4 LT |
258 | } |
259 | ||
260 | EXPORT_SYMBOL(w1_add_master_device); | |
261 | EXPORT_SYMBOL(w1_remove_master_device); |