Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
7785925d | 2 | * w1_int.c |
1da177e4 LT |
3 | * |
4 | * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru> | |
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> |
1da177e4 LT |
26 | |
27 | #include "w1.h" | |
28 | #include "w1_log.h" | |
29 | #include "w1_netlink.h" | |
70d484bf | 30 | #include "w1_int.h" |
1da177e4 | 31 | |
9141f57c DF |
32 | static int w1_search_count = -1; /* Default is continual scan */ |
33 | module_param_named(search_count, w1_search_count, int, 0); | |
1da177e4 | 34 | |
6a158c0d DF |
35 | static int w1_enable_pullup = 1; |
36 | module_param_named(enable_pullup, w1_enable_pullup, int, 0); | |
37 | ||
7785925d EP |
38 | static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl, |
39 | struct device_driver *driver, | |
40 | struct device *device) | |
1da177e4 LT |
41 | { |
42 | struct w1_master *dev; | |
43 | int err; | |
44 | ||
45 | /* | |
46 | * We are in process context(kernel thread), so can sleep. | |
47 | */ | |
dd00cc48 | 48 | dev = kzalloc(sizeof(struct w1_master) + sizeof(struct w1_bus_master), GFP_KERNEL); |
1da177e4 LT |
49 | if (!dev) { |
50 | printk(KERN_ERR | |
51 | "Failed to allocate %zd bytes for new w1 device.\n", | |
52 | sizeof(struct w1_master)); | |
53 | return NULL; | |
54 | } | |
55 | ||
1da177e4 LT |
56 | |
57 | dev->bus_master = (struct w1_bus_master *)(dev + 1); | |
58 | ||
7785925d EP |
59 | dev->owner = THIS_MODULE; |
60 | dev->max_slave_count = slave_count; | |
61 | dev->slave_count = 0; | |
62 | dev->attempts = 0; | |
7785925d EP |
63 | dev->initialized = 0; |
64 | dev->id = id; | |
1da177e4 | 65 | dev->slave_ttl = slave_ttl; |
9141f57c | 66 | dev->search_count = w1_search_count; |
6a158c0d | 67 | dev->enable_pullup = w1_enable_pullup; |
1da177e4 | 68 | |
01e14d6d DF |
69 | /* 1 for w1_process to decrement |
70 | * 1 for __w1_remove_master_device to decrement | |
71 | */ | |
1da177e4 LT |
72 | atomic_set(&dev->refcnt, 2); |
73 | ||
74 | INIT_LIST_HEAD(&dev->slist); | |
abd52a13 | 75 | mutex_init(&dev->mutex); |
1da177e4 | 76 | |
1da177e4 LT |
77 | memcpy(&dev->dev, device, sizeof(struct device)); |
78 | snprintf(dev->dev.bus_id, sizeof(dev->dev.bus_id), | |
79 | "w1_bus_master%u", dev->id); | |
80 | snprintf(dev->name, sizeof(dev->name), "w1_bus_master%u", dev->id); | |
81 | ||
82 | dev->driver = driver; | |
83 | ||
1da177e4 | 84 | dev->seq = 1; |
1da177e4 LT |
85 | |
86 | err = device_register(&dev->dev); | |
87 | if (err) { | |
88 | printk(KERN_ERR "Failed to register master device. err=%d\n", err); | |
1da177e4 LT |
89 | memset(dev, 0, sizeof(struct w1_master)); |
90 | kfree(dev); | |
91 | dev = NULL; | |
92 | } | |
93 | ||
94 | return dev; | |
95 | } | |
96 | ||
2c5bfdac | 97 | static void w1_free_dev(struct w1_master *dev) |
1da177e4 LT |
98 | { |
99 | device_unregister(&dev->dev); | |
1da177e4 LT |
100 | } |
101 | ||
102 | int w1_add_master_device(struct w1_bus_master *master) | |
103 | { | |
af00a2d5 | 104 | struct w1_master *dev, *entry; |
1da177e4 LT |
105 | int retval = 0; |
106 | struct w1_netlink_msg msg; | |
af00a2d5 | 107 | int id, found; |
1da177e4 | 108 | |
be57ce26 EP |
109 | /* validate minimum functionality */ |
110 | if (!(master->touch_bit && master->reset_bus) && | |
c1f858b7 EP |
111 | !(master->write_bit && master->read_bit) && |
112 | !(master->write_byte && master->read_byte && master->reset_bus)) { | |
6adf87bd EP |
113 | printk(KERN_ERR "w1_add_master_device: invalid function set\n"); |
114 | return(-EINVAL); | |
be57ce26 | 115 | } |
6a158c0d DF |
116 | /* While it would be electrically possible to make a device that |
117 | * generated a strong pullup in bit bang mode, only hardare that | |
118 | * controls 1-wire time frames are even expected to support a strong | |
119 | * pullup. w1_io.c would need to support calling set_pullup before | |
120 | * the last write_bit operation of a w1_write_8 which it currently | |
121 | * doesn't. | |
122 | */ | |
123 | if (!master->write_byte && !master->touch_bit && master->set_pullup) { | |
124 | printk(KERN_ERR "w1_add_master_device: set_pullup requires " | |
125 | "write_byte or touch_bit, disabling\n"); | |
126 | master->set_pullup = NULL; | |
127 | } | |
be57ce26 | 128 | |
af00a2d5 DF |
129 | /* Lock until the device is added (or not) to w1_masters. */ |
130 | mutex_lock(&w1_mlock); | |
131 | /* Search for the first available id (starting at 1). */ | |
132 | id = 0; | |
133 | do { | |
134 | ++id; | |
135 | found = 0; | |
136 | list_for_each_entry(entry, &w1_masters, w1_master_entry) { | |
137 | if (entry->id == id) { | |
138 | found = 1; | |
139 | break; | |
140 | } | |
141 | } | |
142 | } while (found); | |
143 | ||
144 | dev = w1_alloc_dev(id, w1_max_slave_count, w1_max_slave_ttl, | |
145 | &w1_master_driver, &w1_master_device); | |
146 | if (!dev) { | |
147 | mutex_unlock(&w1_mlock); | |
1da177e4 | 148 | return -ENOMEM; |
af00a2d5 | 149 | } |
1da177e4 | 150 | |
01e14d6d | 151 | retval = w1_create_master_attributes(dev); |
af00a2d5 DF |
152 | if (retval) { |
153 | mutex_unlock(&w1_mlock); | |
01e14d6d | 154 | goto err_out_free_dev; |
af00a2d5 | 155 | } |
01e14d6d DF |
156 | |
157 | memcpy(dev->bus_master, master, sizeof(struct w1_bus_master)); | |
158 | ||
159 | dev->initialized = 1; | |
160 | ||
674a396c EP |
161 | dev->thread = kthread_run(&w1_process, dev, "%s", dev->name); |
162 | if (IS_ERR(dev->thread)) { | |
163 | retval = PTR_ERR(dev->thread); | |
1da177e4 LT |
164 | dev_err(&dev->dev, |
165 | "Failed to create new kernel thread. err=%d\n", | |
674a396c | 166 | retval); |
af00a2d5 | 167 | mutex_unlock(&w1_mlock); |
01e14d6d | 168 | goto err_out_rm_attr; |
1da177e4 LT |
169 | } |
170 | ||
1da177e4 | 171 | list_add(&dev->w1_master_entry, &w1_masters); |
abd52a13 | 172 | mutex_unlock(&w1_mlock); |
1da177e4 | 173 | |
12003375 | 174 | memset(&msg, 0, sizeof(msg)); |
1da177e4 | 175 | msg.id.mst.id = dev->id; |
1da177e4 LT |
176 | msg.type = W1_MASTER_ADD; |
177 | w1_netlink_send(dev, &msg); | |
178 | ||
179 | return 0; | |
180 | ||
01e14d6d | 181 | #if 0 /* Thread cleanup code, not required currently. */ |
1da177e4 | 182 | err_out_kill_thread: |
674a396c | 183 | kthread_stop(dev->thread); |
01e14d6d DF |
184 | #endif |
185 | err_out_rm_attr: | |
186 | w1_destroy_master_attributes(dev); | |
1da177e4 LT |
187 | err_out_free_dev: |
188 | w1_free_dev(dev); | |
189 | ||
190 | return retval; | |
191 | } | |
192 | ||
193 | void __w1_remove_master_device(struct w1_master *dev) | |
194 | { | |
1da177e4 | 195 | struct w1_netlink_msg msg; |
c30c9b15 | 196 | struct w1_slave *sl, *sln; |
1da177e4 | 197 | |
674a396c | 198 | kthread_stop(dev->thread); |
1da177e4 | 199 | |
c30c9b15 DF |
200 | mutex_lock(&w1_mlock); |
201 | list_del(&dev->w1_master_entry); | |
202 | mutex_unlock(&w1_mlock); | |
203 | ||
204 | mutex_lock(&dev->mutex); | |
205 | list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) | |
206 | w1_slave_detach(sl); | |
207 | w1_destroy_master_attributes(dev); | |
208 | mutex_unlock(&dev->mutex); | |
209 | atomic_dec(&dev->refcnt); | |
210 | ||
1da177e4 | 211 | while (atomic_read(&dev->refcnt)) { |
674a396c | 212 | dev_info(&dev->dev, "Waiting for %s to become free: refcnt=%d.\n", |
1da177e4 LT |
213 | dev->name, atomic_read(&dev->refcnt)); |
214 | ||
215 | if (msleep_interruptible(1000)) | |
216 | flush_signals(current); | |
217 | } | |
218 | ||
12003375 | 219 | memset(&msg, 0, sizeof(msg)); |
1da177e4 | 220 | msg.id.mst.id = dev->id; |
1da177e4 LT |
221 | msg.type = W1_MASTER_REMOVE; |
222 | w1_netlink_send(dev, &msg); | |
223 | ||
224 | w1_free_dev(dev); | |
225 | } | |
226 | ||
227 | void w1_remove_master_device(struct w1_bus_master *bm) | |
228 | { | |
59d9445e | 229 | struct w1_master *dev, *found = NULL; |
1da177e4 | 230 | |
7785925d | 231 | list_for_each_entry(dev, &w1_masters, w1_master_entry) { |
1da177e4 LT |
232 | if (!dev->initialized) |
233 | continue; | |
234 | ||
59d9445e EP |
235 | if (dev->bus_master->data == bm->data) { |
236 | found = dev; | |
1da177e4 | 237 | break; |
59d9445e | 238 | } |
1da177e4 LT |
239 | } |
240 | ||
59d9445e | 241 | if (!found) { |
1da177e4 LT |
242 | printk(KERN_ERR "Device doesn't exist.\n"); |
243 | return; | |
244 | } | |
245 | ||
59d9445e | 246 | __w1_remove_master_device(found); |
1da177e4 LT |
247 | } |
248 | ||
249 | EXPORT_SYMBOL(w1_add_master_device); | |
250 | EXPORT_SYMBOL(w1_remove_master_device); |