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path: root/drivers/isdn/mISDN/timerdev.c
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Diffstat (limited to 'drivers/isdn/mISDN/timerdev.c')
-rw-r--r--drivers/isdn/mISDN/timerdev.c301
1 files changed, 301 insertions, 0 deletions
diff --git a/drivers/isdn/mISDN/timerdev.c b/drivers/isdn/mISDN/timerdev.c
new file mode 100644
index 000000000000..b5fabc7019d8
--- /dev/null
+++ b/drivers/isdn/mISDN/timerdev.c
@@ -0,0 +1,301 @@
1/*
2 *
3 * general timer device for using in ISDN stacks
4 *
5 * Author Karsten Keil <kkeil@novell.com>
6 *
7 * Copyright 2008 by Karsten Keil <kkeil@novell.com>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 */
19
20#include <linux/poll.h>
21#include <linux/vmalloc.h>
22#include <linux/timer.h>
23#include <linux/miscdevice.h>
24#include <linux/module.h>
25#include <linux/mISDNif.h>
26
27static int *debug;
28
29
30struct mISDNtimerdev {
31 int next_id;
32 struct list_head pending;
33 struct list_head expired;
34 wait_queue_head_t wait;
35 u_int work;
36 spinlock_t lock; /* protect lists */
37};
38
39struct mISDNtimer {
40 struct list_head list;
41 struct mISDNtimerdev *dev;
42 struct timer_list tl;
43 int id;
44};
45
46static int
47mISDN_open(struct inode *ino, struct file *filep)
48{
49 struct mISDNtimerdev *dev;
50
51 if (*debug & DEBUG_TIMER)
52 printk(KERN_DEBUG "%s(%p,%p)\n", __func__, ino, filep);
53 dev = kmalloc(sizeof(struct mISDNtimerdev) , GFP_KERNEL);
54 if (!dev)
55 return -ENOMEM;
56 dev->next_id = 1;
57 INIT_LIST_HEAD(&dev->pending);
58 INIT_LIST_HEAD(&dev->expired);
59 spin_lock_init(&dev->lock);
60 dev->work = 0;
61 init_waitqueue_head(&dev->wait);
62 filep->private_data = dev;
63 __module_get(THIS_MODULE);
64 return 0;
65}
66
67static int
68mISDN_close(struct inode *ino, struct file *filep)
69{
70 struct mISDNtimerdev *dev = filep->private_data;
71 struct mISDNtimer *timer, *next;
72
73 if (*debug & DEBUG_TIMER)
74 printk(KERN_DEBUG "%s(%p,%p)\n", __func__, ino, filep);
75 list_for_each_entry_safe(timer, next, &dev->pending, list) {
76 del_timer(&timer->tl);
77 kfree(timer);
78 }
79 list_for_each_entry_safe(timer, next, &dev->expired, list) {
80 kfree(timer);
81 }
82 kfree(dev);
83 module_put(THIS_MODULE);
84 return 0;
85}
86
87static ssize_t
88mISDN_read(struct file *filep, char *buf, size_t count, loff_t *off)
89{
90 struct mISDNtimerdev *dev = filep->private_data;
91 struct mISDNtimer *timer;
92 u_long flags;
93 int ret = 0;
94
95 if (*debug & DEBUG_TIMER)
96 printk(KERN_DEBUG "%s(%p, %p, %d, %p)\n", __func__,
97 filep, buf, (int)count, off);
98 if (*off != filep->f_pos)
99 return -ESPIPE;
100
101 if (list_empty(&dev->expired) && (dev->work == 0)) {
102 if (filep->f_flags & O_NONBLOCK)
103 return -EAGAIN;
104 wait_event_interruptible(dev->wait, (dev->work ||
105 !list_empty(&dev->expired)));
106 if (signal_pending(current))
107 return -ERESTARTSYS;
108 }
109 if (count < sizeof(int))
110 return -ENOSPC;
111 if (dev->work)
112 dev->work = 0;
113 if (!list_empty(&dev->expired)) {
114 spin_lock_irqsave(&dev->lock, flags);
115 timer = (struct mISDNtimer *)dev->expired.next;
116 list_del(&timer->list);
117 spin_unlock_irqrestore(&dev->lock, flags);
118 if (put_user(timer->id, (int *)buf))
119 ret = -EFAULT;
120 else
121 ret = sizeof(int);
122 kfree(timer);
123 }
124 return ret;
125}
126
127static loff_t
128mISDN_llseek(struct file *filep, loff_t offset, int orig)
129{
130 return -ESPIPE;
131}
132
133static ssize_t
134mISDN_write(struct file *filep, const char *buf, size_t count, loff_t *off)
135{
136 return -EOPNOTSUPP;
137}
138
139static unsigned int
140mISDN_poll(struct file *filep, poll_table *wait)
141{
142 struct mISDNtimerdev *dev = filep->private_data;
143 unsigned int mask = POLLERR;
144
145 if (*debug & DEBUG_TIMER)
146 printk(KERN_DEBUG "%s(%p, %p)\n", __func__, filep, wait);
147 if (dev) {
148 poll_wait(filep, &dev->wait, wait);
149 mask = 0;
150 if (dev->work || !list_empty(&dev->expired))
151 mask |= (POLLIN | POLLRDNORM);
152 if (*debug & DEBUG_TIMER)
153 printk(KERN_DEBUG "%s work(%d) empty(%d)\n", __func__,
154 dev->work, list_empty(&dev->expired));
155 }
156 return mask;
157}
158
159static void
160dev_expire_timer(struct mISDNtimer *timer)
161{
162 u_long flags;
163
164 spin_lock_irqsave(&timer->dev->lock, flags);
165 list_del(&timer->list);
166 list_add_tail(&timer->list, &timer->dev->expired);
167 spin_unlock_irqrestore(&timer->dev->lock, flags);
168 wake_up_interruptible(&timer->dev->wait);
169}
170
171static int
172misdn_add_timer(struct mISDNtimerdev *dev, int timeout)
173{
174 int id;
175 u_long flags;
176 struct mISDNtimer *timer;
177
178 if (!timeout) {
179 dev->work = 1;
180 wake_up_interruptible(&dev->wait);
181 id = 0;
182 } else {
183 timer = kzalloc(sizeof(struct mISDNtimer), GFP_KERNEL);
184 if (!timer)
185 return -ENOMEM;
186 spin_lock_irqsave(&dev->lock, flags);
187 timer->id = dev->next_id++;
188 if (dev->next_id < 0)
189 dev->next_id = 1;
190 list_add_tail(&timer->list, &dev->pending);
191 spin_unlock_irqrestore(&dev->lock, flags);
192 timer->dev = dev;
193 timer->tl.data = (long)timer;
194 timer->tl.function = (void *) dev_expire_timer;
195 init_timer(&timer->tl);
196 timer->tl.expires = jiffies + ((HZ * (u_long)timeout) / 1000);
197 add_timer(&timer->tl);
198 id = timer->id;
199 }
200 return id;
201}
202
203static int
204misdn_del_timer(struct mISDNtimerdev *dev, int id)
205{
206 u_long flags;
207 struct mISDNtimer *timer;
208 int ret = 0;
209
210 spin_lock_irqsave(&dev->lock, flags);
211 list_for_each_entry(timer, &dev->pending, list) {
212 if (timer->id == id) {
213 list_del_init(&timer->list);
214 del_timer(&timer->tl);
215 ret = timer->id;
216 kfree(timer);
217 goto unlock;
218 }
219 }
220unlock:
221 spin_unlock_irqrestore(&dev->lock, flags);
222 return ret;
223}
224
225static int
226mISDN_ioctl(struct inode *inode, struct file *filep, unsigned int cmd,
227 unsigned long arg)
228{
229 struct mISDNtimerdev *dev = filep->private_data;
230 int id, tout, ret = 0;
231
232
233 if (*debug & DEBUG_TIMER)
234 printk(KERN_DEBUG "%s(%p, %x, %lx)\n", __func__,
235 filep, cmd, arg);
236 switch (cmd) {
237 case IMADDTIMER:
238 if (get_user(tout, (int __user *)arg)) {
239 ret = -EFAULT;
240 break;
241 }
242 id = misdn_add_timer(dev, tout);
243 if (*debug & DEBUG_TIMER)
244 printk(KERN_DEBUG "%s add %d id %d\n", __func__,
245 tout, id);
246 if (id < 0) {
247 ret = id;
248 break;
249 }
250 if (put_user(id, (int __user *)arg))
251 ret = -EFAULT;
252 break;
253 case IMDELTIMER:
254 if (get_user(id, (int __user *)arg)) {
255 ret = -EFAULT;
256 break;
257 }
258 if (*debug & DEBUG_TIMER)
259 printk(KERN_DEBUG "%s del id %d\n", __func__, id);
260 id = misdn_del_timer(dev, id);
261 if (put_user(id, (int __user *)arg))
262 ret = -EFAULT;
263 break;
264 default:
265 ret = -EINVAL;
266 }
267 return ret;
268}
269
270static struct file_operations mISDN_fops = {
271 .llseek = mISDN_llseek,
272 .read = mISDN_read,
273 .write = mISDN_write,
274 .poll = mISDN_poll,
275 .ioctl = mISDN_ioctl,
276 .open = mISDN_open,
277 .release = mISDN_close,
278};
279
280static struct miscdevice mISDNtimer = {
281 .minor = MISC_DYNAMIC_MINOR,
282 .name = "mISDNtimer",
283 .fops = &mISDN_fops,
284};
285
286int
287mISDN_inittimer(int *deb)
288{
289 int err;
290
291 debug = deb;
292 err = misc_register(&mISDNtimer);
293 if (err)
294 printk(KERN_WARNING "mISDN: Could not register timer device\n");
295 return err;
296}
297
298void mISDN_timer_cleanup(void)
299{
300 misc_deregister(&mISDNtimer);
301}