2 * posix-clock.c - support for dynamic clock devices
4 * Copyright (C) 2010 OMICRON electronics GmbH
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 #include <linux/device.h>
21 #include <linux/export.h>
22 #include <linux/file.h>
23 #include <linux/posix-clock.h>
24 #include <linux/slab.h>
25 #include <linux/syscalls.h>
26 #include <linux/uaccess.h>
29 * Returns NULL if the posix_clock instance attached to 'fp' is old and stale.
31 static struct posix_clock *get_posix_clock(struct file *fp)
33 struct posix_clock *clk = fp->private_data;
35 down_read(&clk->rwsem);
45 static void put_posix_clock(struct posix_clock *clk)
50 static ssize_t posix_clock_read(struct file *fp, char __user *buf,
51 size_t count, loff_t *ppos)
53 struct posix_clock *clk = get_posix_clock(fp);
60 err = clk->ops.read(clk, fp->f_flags, buf, count);
67 static unsigned int posix_clock_poll(struct file *fp, poll_table *wait)
69 struct posix_clock *clk = get_posix_clock(fp);
70 unsigned int result = 0;
76 result = clk->ops.poll(clk, fp, wait);
83 static int posix_clock_fasync(int fd, struct file *fp, int on)
85 struct posix_clock *clk = get_posix_clock(fp);
92 err = clk->ops.fasync(clk, fd, fp, on);
99 static int posix_clock_mmap(struct file *fp, struct vm_area_struct *vma)
101 struct posix_clock *clk = get_posix_clock(fp);
108 err = clk->ops.mmap(clk, vma);
110 put_posix_clock(clk);
115 static long posix_clock_ioctl(struct file *fp,
116 unsigned int cmd, unsigned long arg)
118 struct posix_clock *clk = get_posix_clock(fp);
125 err = clk->ops.ioctl(clk, cmd, arg);
127 put_posix_clock(clk);
133 static long posix_clock_compat_ioctl(struct file *fp,
134 unsigned int cmd, unsigned long arg)
136 struct posix_clock *clk = get_posix_clock(fp);
143 err = clk->ops.ioctl(clk, cmd, arg);
145 put_posix_clock(clk);
151 static int posix_clock_open(struct inode *inode, struct file *fp)
154 struct posix_clock *clk =
155 container_of(inode->i_cdev, struct posix_clock, cdev);
157 down_read(&clk->rwsem);
164 err = clk->ops.open(clk, fp->f_mode);
169 get_device(clk->dev);
170 fp->private_data = clk;
173 up_read(&clk->rwsem);
177 static int posix_clock_release(struct inode *inode, struct file *fp)
179 struct posix_clock *clk = fp->private_data;
182 if (clk->ops.release)
183 err = clk->ops.release(clk);
185 put_device(clk->dev);
187 fp->private_data = NULL;
192 static const struct file_operations posix_clock_file_operations = {
193 .owner = THIS_MODULE,
195 .read = posix_clock_read,
196 .poll = posix_clock_poll,
197 .unlocked_ioctl = posix_clock_ioctl,
198 .open = posix_clock_open,
199 .release = posix_clock_release,
200 .fasync = posix_clock_fasync,
201 .mmap = posix_clock_mmap,
203 .compat_ioctl = posix_clock_compat_ioctl,
207 int posix_clock_register(struct posix_clock *clk, struct device *dev)
211 init_rwsem(&clk->rwsem);
213 cdev_init(&clk->cdev, &posix_clock_file_operations);
214 err = cdev_device_add(&clk->cdev, dev);
216 pr_err("%s unable to add device %d:%d\n",
217 dev_name(dev), MAJOR(dev->devt), MINOR(dev->devt));
220 clk->cdev.owner = clk->ops.owner;
225 EXPORT_SYMBOL_GPL(posix_clock_register);
227 void posix_clock_unregister(struct posix_clock *clk)
229 cdev_device_del(&clk->cdev, clk->dev);
231 down_write(&clk->rwsem);
233 up_write(&clk->rwsem);
235 put_device(clk->dev);
237 EXPORT_SYMBOL_GPL(posix_clock_unregister);
239 struct posix_clock_desc {
241 struct posix_clock *clk;
244 static int get_clock_desc(const clockid_t id, struct posix_clock_desc *cd)
246 struct file *fp = fget(CLOCKID_TO_FD(id));
252 if (fp->f_op->open != posix_clock_open || !fp->private_data)
256 cd->clk = get_posix_clock(fp);
258 err = cd->clk ? 0 : -ENODEV;
265 static void put_clock_desc(struct posix_clock_desc *cd)
267 put_posix_clock(cd->clk);
271 static int pc_clock_adjtime(clockid_t id, struct timex *tx)
273 struct posix_clock_desc cd;
276 err = get_clock_desc(id, &cd);
280 if ((cd.fp->f_mode & FMODE_WRITE) == 0) {
285 if (cd.clk->ops.clock_adjtime)
286 err = cd.clk->ops.clock_adjtime(cd.clk, tx);
295 static int pc_clock_gettime(clockid_t id, struct timespec *ts)
297 struct posix_clock_desc cd;
298 struct timespec64 ts64;
301 err = get_clock_desc(id, &cd);
305 if (cd.clk->ops.clock_gettime) {
306 err = cd.clk->ops.clock_gettime(cd.clk, &ts64);
307 *ts = timespec64_to_timespec(ts64);
317 static int pc_clock_getres(clockid_t id, struct timespec *ts)
319 struct posix_clock_desc cd;
320 struct timespec64 ts64;
323 err = get_clock_desc(id, &cd);
327 if (cd.clk->ops.clock_getres) {
328 err = cd.clk->ops.clock_getres(cd.clk, &ts64);
329 *ts = timespec64_to_timespec(ts64);
339 static int pc_clock_settime(clockid_t id, const struct timespec *ts)
341 struct timespec64 ts64 = timespec_to_timespec64(*ts);
342 struct posix_clock_desc cd;
345 err = get_clock_desc(id, &cd);
349 if ((cd.fp->f_mode & FMODE_WRITE) == 0) {
354 if (cd.clk->ops.clock_settime)
355 err = cd.clk->ops.clock_settime(cd.clk, &ts64);
364 static int pc_timer_create(struct k_itimer *kit)
366 clockid_t id = kit->it_clock;
367 struct posix_clock_desc cd;
370 err = get_clock_desc(id, &cd);
374 if (cd.clk->ops.timer_create)
375 err = cd.clk->ops.timer_create(cd.clk, kit);
384 static int pc_timer_delete(struct k_itimer *kit)
386 clockid_t id = kit->it_clock;
387 struct posix_clock_desc cd;
390 err = get_clock_desc(id, &cd);
394 if (cd.clk->ops.timer_delete)
395 err = cd.clk->ops.timer_delete(cd.clk, kit);
404 static void pc_timer_gettime(struct k_itimer *kit, struct itimerspec *ts)
406 clockid_t id = kit->it_clock;
407 struct posix_clock_desc cd;
408 struct itimerspec64 ts64;
410 if (get_clock_desc(id, &cd))
413 if (cd.clk->ops.timer_gettime) {
414 cd.clk->ops.timer_gettime(cd.clk, kit, &ts64);
415 *ts = itimerspec64_to_itimerspec(&ts64);
420 static int pc_timer_settime(struct k_itimer *kit, int flags,
421 struct itimerspec *ts, struct itimerspec *old)
423 struct itimerspec64 ts64 = itimerspec_to_itimerspec64(ts);
424 clockid_t id = kit->it_clock;
425 struct posix_clock_desc cd;
426 struct itimerspec64 old64;
429 err = get_clock_desc(id, &cd);
433 if (cd.clk->ops.timer_settime) {
434 err = cd.clk->ops.timer_settime(cd.clk, kit, flags, &ts64, &old64);
436 *old = itimerspec64_to_itimerspec(&old64);
446 struct k_clock clock_posix_dynamic = {
447 .clock_getres = pc_clock_getres,
448 .clock_set = pc_clock_settime,
449 .clock_get = pc_clock_gettime,
450 .clock_adj = pc_clock_adjtime,
451 .timer_create = pc_timer_create,
452 .timer_set = pc_timer_settime,
453 .timer_del = pc_timer_delete,
454 .timer_get = pc_timer_gettime,