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Commit | Line | Data |
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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> | |
25 | ||
26 | #include "w1.h" | |
27 | #include "w1_log.h" | |
28 | #include "w1_netlink.h" | |
29 | ||
30 | static u32 w1_ids = 1; | |
31 | ||
32 | extern struct device_driver w1_driver; | |
33 | extern struct bus_type w1_bus_type; | |
34 | extern struct device w1_device; | |
35 | extern int w1_max_slave_count; | |
36 | extern int w1_max_slave_ttl; | |
37 | extern struct list_head w1_masters; | |
38 | extern spinlock_t w1_mlock; | |
39 | ||
40 | extern int w1_process(void *); | |
41 | ||
7785925d EP |
42 | static struct w1_master * w1_alloc_dev(u32 id, int slave_count, int slave_ttl, |
43 | struct device_driver *driver, | |
44 | struct device *device) | |
1da177e4 LT |
45 | { |
46 | struct w1_master *dev; | |
47 | int err; | |
48 | ||
49 | /* | |
50 | * We are in process context(kernel thread), so can sleep. | |
51 | */ | |
52 | dev = kmalloc(sizeof(struct w1_master) + sizeof(struct w1_bus_master), GFP_KERNEL); | |
53 | if (!dev) { | |
54 | printk(KERN_ERR | |
55 | "Failed to allocate %zd bytes for new w1 device.\n", | |
56 | sizeof(struct w1_master)); | |
57 | return NULL; | |
58 | } | |
59 | ||
60 | memset(dev, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master)); | |
61 | ||
62 | dev->bus_master = (struct w1_bus_master *)(dev + 1); | |
63 | ||
7785925d EP |
64 | dev->owner = THIS_MODULE; |
65 | dev->max_slave_count = slave_count; | |
66 | dev->slave_count = 0; | |
67 | dev->attempts = 0; | |
68 | dev->kpid = -1; | |
69 | dev->initialized = 0; | |
70 | dev->id = id; | |
1da177e4 | 71 | dev->slave_ttl = slave_ttl; |
2a9d0c17 | 72 | dev->search_count = -1; /* continual scan */ |
1da177e4 LT |
73 | |
74 | atomic_set(&dev->refcnt, 2); | |
75 | ||
76 | INIT_LIST_HEAD(&dev->slist); | |
77 | init_MUTEX(&dev->mutex); | |
78 | ||
79 | init_completion(&dev->dev_released); | |
80 | init_completion(&dev->dev_exited); | |
81 | ||
82 | memcpy(&dev->dev, device, sizeof(struct device)); | |
83 | snprintf(dev->dev.bus_id, sizeof(dev->dev.bus_id), | |
84 | "w1_bus_master%u", dev->id); | |
85 | snprintf(dev->name, sizeof(dev->name), "w1_bus_master%u", dev->id); | |
86 | ||
87 | dev->driver = driver; | |
88 | ||
89 | dev->groups = 23; | |
90 | dev->seq = 1; | |
91 | dev->nls = netlink_kernel_create(NETLINK_NFLOG, NULL); | |
92 | if (!dev->nls) { | |
93 | printk(KERN_ERR "Failed to create new netlink socket(%u) for w1 master %s.\n", | |
94 | NETLINK_NFLOG, dev->dev.bus_id); | |
95 | } | |
96 | ||
97 | err = device_register(&dev->dev); | |
98 | if (err) { | |
99 | printk(KERN_ERR "Failed to register master device. err=%d\n", err); | |
100 | if (dev->nls && dev->nls->sk_socket) | |
101 | sock_release(dev->nls->sk_socket); | |
102 | memset(dev, 0, sizeof(struct w1_master)); | |
103 | kfree(dev); | |
104 | dev = NULL; | |
105 | } | |
106 | ||
107 | return dev; | |
108 | } | |
109 | ||
7785925d | 110 | static void w1_free_dev(struct w1_master *dev) |
1da177e4 LT |
111 | { |
112 | device_unregister(&dev->dev); | |
113 | if (dev->nls && dev->nls->sk_socket) | |
114 | sock_release(dev->nls->sk_socket); | |
115 | memset(dev, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master)); | |
116 | kfree(dev); | |
117 | } | |
118 | ||
119 | int w1_add_master_device(struct w1_bus_master *master) | |
120 | { | |
121 | struct w1_master *dev; | |
122 | int retval = 0; | |
123 | struct w1_netlink_msg msg; | |
124 | ||
be57ce26 EP |
125 | /* validate minimum functionality */ |
126 | if (!(master->touch_bit && master->reset_bus) && | |
127 | !(master->write_bit && master->read_bit)) | |
128 | { | |
129 | printk(KERN_ERR "w1_add_master_device: invalid function set\n"); | |
130 | return(-EINVAL); | |
131 | } | |
132 | ||
1da177e4 LT |
133 | dev = w1_alloc_dev(w1_ids++, w1_max_slave_count, w1_max_slave_ttl, &w1_driver, &w1_device); |
134 | if (!dev) | |
135 | return -ENOMEM; | |
136 | ||
137 | dev->kpid = kernel_thread(&w1_process, dev, 0); | |
138 | if (dev->kpid < 0) { | |
139 | dev_err(&dev->dev, | |
140 | "Failed to create new kernel thread. err=%d\n", | |
141 | dev->kpid); | |
142 | retval = dev->kpid; | |
143 | goto err_out_free_dev; | |
144 | } | |
145 | ||
146 | retval = w1_create_master_attributes(dev); | |
147 | if (retval) | |
148 | goto err_out_kill_thread; | |
149 | ||
150 | memcpy(dev->bus_master, master, sizeof(struct w1_bus_master)); | |
151 | ||
152 | dev->initialized = 1; | |
153 | ||
154 | spin_lock(&w1_mlock); | |
155 | list_add(&dev->w1_master_entry, &w1_masters); | |
156 | spin_unlock(&w1_mlock); | |
157 | ||
158 | msg.id.mst.id = dev->id; | |
159 | msg.id.mst.pid = dev->kpid; | |
160 | msg.type = W1_MASTER_ADD; | |
161 | w1_netlink_send(dev, &msg); | |
162 | ||
163 | return 0; | |
164 | ||
165 | err_out_kill_thread: | |
166 | dev->need_exit = 1; | |
167 | if (kill_proc(dev->kpid, SIGTERM, 1)) | |
168 | dev_err(&dev->dev, | |
169 | "Failed to send signal to w1 kernel thread %d.\n", | |
170 | dev->kpid); | |
171 | wait_for_completion(&dev->dev_exited); | |
172 | ||
173 | err_out_free_dev: | |
174 | w1_free_dev(dev); | |
175 | ||
176 | return retval; | |
177 | } | |
178 | ||
179 | void __w1_remove_master_device(struct w1_master *dev) | |
180 | { | |
181 | int err; | |
182 | struct w1_netlink_msg msg; | |
183 | ||
184 | dev->need_exit = 1; | |
185 | err = kill_proc(dev->kpid, SIGTERM, 1); | |
186 | if (err) | |
187 | dev_err(&dev->dev, | |
188 | "%s: Failed to send signal to w1 kernel thread %d.\n", | |
189 | __func__, dev->kpid); | |
190 | ||
191 | while (atomic_read(&dev->refcnt)) { | |
192 | printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n", | |
193 | dev->name, atomic_read(&dev->refcnt)); | |
194 | ||
195 | if (msleep_interruptible(1000)) | |
196 | flush_signals(current); | |
197 | } | |
198 | ||
199 | msg.id.mst.id = dev->id; | |
200 | msg.id.mst.pid = dev->kpid; | |
201 | msg.type = W1_MASTER_REMOVE; | |
202 | w1_netlink_send(dev, &msg); | |
203 | ||
204 | w1_free_dev(dev); | |
205 | } | |
206 | ||
207 | void w1_remove_master_device(struct w1_bus_master *bm) | |
208 | { | |
209 | struct w1_master *dev = NULL; | |
1da177e4 | 210 | |
7785925d | 211 | list_for_each_entry(dev, &w1_masters, w1_master_entry) { |
1da177e4 LT |
212 | if (!dev->initialized) |
213 | continue; | |
214 | ||
215 | if (dev->bus_master->data == bm->data) | |
216 | break; | |
217 | } | |
218 | ||
219 | if (!dev) { | |
220 | printk(KERN_ERR "Device doesn't exist.\n"); | |
221 | return; | |
222 | } | |
223 | ||
224 | __w1_remove_master_device(dev); | |
225 | } | |
226 | ||
227 | EXPORT_SYMBOL(w1_add_master_device); | |
228 | EXPORT_SYMBOL(w1_remove_master_device); |