Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
a8018766 | 2 | * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net> |
7785925d | 3 | * |
1da177e4 LT |
4 | * This program is free software; you can redistribute it and/or modify |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
1da177e4 LT |
13 | */ |
14 | ||
15 | #include <linux/kernel.h> | |
16 | #include <linux/list.h> | |
17 | #include <linux/delay.h> | |
674a396c | 18 | #include <linux/kthread.h> |
5a0e3ad6 | 19 | #include <linux/slab.h> |
3f07c014 | 20 | #include <linux/sched/signal.h> |
9623932c | 21 | #include <linux/export.h> |
4d184129 | 22 | #include <linux/moduleparam.h> |
1da177e4 LT |
23 | |
24 | #include "w1.h" | |
1da177e4 | 25 | #include "w1_netlink.h" |
70d484bf | 26 | #include "w1_int.h" |
1da177e4 | 27 | |
9141f57c DF |
28 | static int w1_search_count = -1; /* Default is continual scan */ |
29 | module_param_named(search_count, w1_search_count, int, 0); | |
1da177e4 | 30 | |
6a158c0d DF |
31 | static int w1_enable_pullup = 1; |
32 | module_param_named(enable_pullup, w1_enable_pullup, int, 0); | |
33 | ||
7242d42a | 34 | static struct w1_master *w1_alloc_dev(u32 id, int slave_count, int slave_ttl, |
7785925d EP |
35 | struct device_driver *driver, |
36 | struct device *device) | |
1da177e4 LT |
37 | { |
38 | struct w1_master *dev; | |
39 | int err; | |
40 | ||
41 | /* | |
42 | * We are in process context(kernel thread), so can sleep. | |
43 | */ | |
dd00cc48 | 44 | dev = kzalloc(sizeof(struct w1_master) + sizeof(struct w1_bus_master), GFP_KERNEL); |
1da177e4 | 45 | if (!dev) { |
fdc9167a | 46 | pr_err("Failed to allocate %zd bytes for new w1 device.\n", |
1da177e4 LT |
47 | sizeof(struct w1_master)); |
48 | return NULL; | |
49 | } | |
50 | ||
1da177e4 LT |
51 | |
52 | dev->bus_master = (struct w1_bus_master *)(dev + 1); | |
53 | ||
7785925d EP |
54 | dev->owner = THIS_MODULE; |
55 | dev->max_slave_count = slave_count; | |
56 | dev->slave_count = 0; | |
57 | dev->attempts = 0; | |
7785925d EP |
58 | dev->initialized = 0; |
59 | dev->id = id; | |
1da177e4 | 60 | dev->slave_ttl = slave_ttl; |
9141f57c | 61 | dev->search_count = w1_search_count; |
6a158c0d | 62 | dev->enable_pullup = w1_enable_pullup; |
1da177e4 | 63 | |
01e14d6d DF |
64 | /* 1 for w1_process to decrement |
65 | * 1 for __w1_remove_master_device to decrement | |
66 | */ | |
1da177e4 LT |
67 | atomic_set(&dev->refcnt, 2); |
68 | ||
69 | INIT_LIST_HEAD(&dev->slist); | |
9fcbbac5 | 70 | INIT_LIST_HEAD(&dev->async_list); |
abd52a13 | 71 | mutex_init(&dev->mutex); |
b02f8bed | 72 | mutex_init(&dev->bus_mutex); |
9fcbbac5 | 73 | mutex_init(&dev->list_mutex); |
1da177e4 | 74 | |
1da177e4 | 75 | memcpy(&dev->dev, device, sizeof(struct device)); |
40f91de6 | 76 | dev_set_name(&dev->dev, "w1_bus_master%u", dev->id); |
1da177e4 | 77 | snprintf(dev->name, sizeof(dev->name), "w1_bus_master%u", dev->id); |
68a436ae | 78 | dev->dev.init_name = dev->name; |
1da177e4 LT |
79 | |
80 | dev->driver = driver; | |
81 | ||
1da177e4 | 82 | dev->seq = 1; |
1da177e4 LT |
83 | |
84 | err = device_register(&dev->dev); | |
85 | if (err) { | |
fdc9167a | 86 | pr_err("Failed to register master device. err=%d\n", err); |
5052436d | 87 | put_device(&dev->dev); |
1da177e4 LT |
88 | dev = NULL; |
89 | } | |
90 | ||
91 | return dev; | |
92 | } | |
93 | ||
2c5bfdac | 94 | static void w1_free_dev(struct w1_master *dev) |
1da177e4 LT |
95 | { |
96 | device_unregister(&dev->dev); | |
1da177e4 LT |
97 | } |
98 | ||
b3be177a DF |
99 | /** |
100 | * w1_add_master_device() - registers a new master device | |
101 | * @master: master bus device to register | |
102 | */ | |
1da177e4 LT |
103 | int w1_add_master_device(struct w1_bus_master *master) |
104 | { | |
af00a2d5 | 105 | struct w1_master *dev, *entry; |
1da177e4 LT |
106 | int retval = 0; |
107 | struct w1_netlink_msg msg; | |
af00a2d5 | 108 | int id, found; |
1da177e4 | 109 | |
7242d42a TW |
110 | /* validate minimum functionality */ |
111 | if (!(master->touch_bit && master->reset_bus) && | |
112 | !(master->write_bit && master->read_bit) && | |
c1f858b7 | 113 | !(master->write_byte && master->read_byte && master->reset_bus)) { |
fdc9167a | 114 | pr_err("w1_add_master_device: invalid function set\n"); |
6adf87bd | 115 | return(-EINVAL); |
7242d42a | 116 | } |
be57ce26 | 117 | |
af00a2d5 DF |
118 | /* Lock until the device is added (or not) to w1_masters. */ |
119 | mutex_lock(&w1_mlock); | |
120 | /* Search for the first available id (starting at 1). */ | |
121 | id = 0; | |
122 | do { | |
123 | ++id; | |
124 | found = 0; | |
125 | list_for_each_entry(entry, &w1_masters, w1_master_entry) { | |
126 | if (entry->id == id) { | |
127 | found = 1; | |
128 | break; | |
129 | } | |
130 | } | |
131 | } while (found); | |
132 | ||
133 | dev = w1_alloc_dev(id, w1_max_slave_count, w1_max_slave_ttl, | |
134 | &w1_master_driver, &w1_master_device); | |
135 | if (!dev) { | |
136 | mutex_unlock(&w1_mlock); | |
1da177e4 | 137 | return -ENOMEM; |
af00a2d5 | 138 | } |
1da177e4 | 139 | |
01e14d6d | 140 | retval = w1_create_master_attributes(dev); |
af00a2d5 DF |
141 | if (retval) { |
142 | mutex_unlock(&w1_mlock); | |
01e14d6d | 143 | goto err_out_free_dev; |
af00a2d5 | 144 | } |
01e14d6d DF |
145 | |
146 | memcpy(dev->bus_master, master, sizeof(struct w1_bus_master)); | |
147 | ||
148 | dev->initialized = 1; | |
149 | ||
674a396c EP |
150 | dev->thread = kthread_run(&w1_process, dev, "%s", dev->name); |
151 | if (IS_ERR(dev->thread)) { | |
152 | retval = PTR_ERR(dev->thread); | |
1da177e4 LT |
153 | dev_err(&dev->dev, |
154 | "Failed to create new kernel thread. err=%d\n", | |
674a396c | 155 | retval); |
af00a2d5 | 156 | mutex_unlock(&w1_mlock); |
01e14d6d | 157 | goto err_out_rm_attr; |
1da177e4 LT |
158 | } |
159 | ||
1da177e4 | 160 | list_add(&dev->w1_master_entry, &w1_masters); |
abd52a13 | 161 | mutex_unlock(&w1_mlock); |
1da177e4 | 162 | |
12003375 | 163 | memset(&msg, 0, sizeof(msg)); |
1da177e4 | 164 | msg.id.mst.id = dev->id; |
1da177e4 LT |
165 | msg.type = W1_MASTER_ADD; |
166 | w1_netlink_send(dev, &msg); | |
167 | ||
168 | return 0; | |
169 | ||
01e14d6d | 170 | #if 0 /* Thread cleanup code, not required currently. */ |
1da177e4 | 171 | err_out_kill_thread: |
42105698 | 172 | set_bit(W1_ABORT_SEARCH, &dev->flags); |
674a396c | 173 | kthread_stop(dev->thread); |
01e14d6d DF |
174 | #endif |
175 | err_out_rm_attr: | |
176 | w1_destroy_master_attributes(dev); | |
1da177e4 LT |
177 | err_out_free_dev: |
178 | w1_free_dev(dev); | |
179 | ||
180 | return retval; | |
181 | } | |
182 | ||
183 | void __w1_remove_master_device(struct w1_master *dev) | |
184 | { | |
1da177e4 | 185 | struct w1_netlink_msg msg; |
c30c9b15 | 186 | struct w1_slave *sl, *sln; |
1da177e4 | 187 | |
c30c9b15 DF |
188 | mutex_lock(&w1_mlock); |
189 | list_del(&dev->w1_master_entry); | |
190 | mutex_unlock(&w1_mlock); | |
191 | ||
9fcbbac5 DF |
192 | set_bit(W1_ABORT_SEARCH, &dev->flags); |
193 | kthread_stop(dev->thread); | |
194 | ||
c30c9b15 | 195 | mutex_lock(&dev->mutex); |
9fcbbac5 DF |
196 | mutex_lock(&dev->list_mutex); |
197 | list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) { | |
198 | mutex_unlock(&dev->list_mutex); | |
c30c9b15 | 199 | w1_slave_detach(sl); |
9fcbbac5 DF |
200 | mutex_lock(&dev->list_mutex); |
201 | } | |
c30c9b15 | 202 | w1_destroy_master_attributes(dev); |
9fcbbac5 | 203 | mutex_unlock(&dev->list_mutex); |
c30c9b15 DF |
204 | mutex_unlock(&dev->mutex); |
205 | atomic_dec(&dev->refcnt); | |
206 | ||
1da177e4 | 207 | while (atomic_read(&dev->refcnt)) { |
674a396c | 208 | dev_info(&dev->dev, "Waiting for %s to become free: refcnt=%d.\n", |
1da177e4 LT |
209 | dev->name, atomic_read(&dev->refcnt)); |
210 | ||
211 | if (msleep_interruptible(1000)) | |
212 | flush_signals(current); | |
a0f10464 | 213 | mutex_lock(&dev->list_mutex); |
9fcbbac5 | 214 | w1_process_callbacks(dev); |
a0f10464 | 215 | mutex_unlock(&dev->list_mutex); |
1da177e4 | 216 | } |
a0f10464 | 217 | mutex_lock(&dev->list_mutex); |
9fcbbac5 | 218 | w1_process_callbacks(dev); |
a0f10464 | 219 | mutex_unlock(&dev->list_mutex); |
1da177e4 | 220 | |
12003375 | 221 | memset(&msg, 0, sizeof(msg)); |
1da177e4 | 222 | msg.id.mst.id = dev->id; |
1da177e4 LT |
223 | msg.type = W1_MASTER_REMOVE; |
224 | w1_netlink_send(dev, &msg); | |
225 | ||
226 | w1_free_dev(dev); | |
227 | } | |
228 | ||
b3be177a DF |
229 | /** |
230 | * w1_remove_master_device() - unregister a master device | |
231 | * @bm: master bus device to remove | |
232 | */ | |
1da177e4 LT |
233 | void w1_remove_master_device(struct w1_bus_master *bm) |
234 | { | |
59d9445e | 235 | struct w1_master *dev, *found = NULL; |
1da177e4 | 236 | |
7785925d | 237 | list_for_each_entry(dev, &w1_masters, w1_master_entry) { |
1da177e4 LT |
238 | if (!dev->initialized) |
239 | continue; | |
240 | ||
59d9445e EP |
241 | if (dev->bus_master->data == bm->data) { |
242 | found = dev; | |
1da177e4 | 243 | break; |
59d9445e | 244 | } |
1da177e4 LT |
245 | } |
246 | ||
59d9445e | 247 | if (!found) { |
fdc9167a | 248 | pr_err("Device doesn't exist.\n"); |
1da177e4 LT |
249 | return; |
250 | } | |
251 | ||
59d9445e | 252 | __w1_remove_master_device(found); |
1da177e4 LT |
253 | } |
254 | ||
255 | EXPORT_SYMBOL(w1_add_master_device); | |
256 | EXPORT_SYMBOL(w1_remove_master_device); |