blob: 6437703eb10fdfa484097a692af6ee2c20559b4b [file] [log] [blame]
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -07001/*
2 * PPS core file
3 *
4 *
5 * Copyright (C) 2005-2009 Rodolfo Giometti <giometti@linux.it>
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., 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21
Alexander Gordeev7f7cce72011-01-12 17:00:52 -080022#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -070023
24#include <linux/kernel.h>
25#include <linux/module.h>
26#include <linux/init.h>
27#include <linux/sched.h>
28#include <linux/uaccess.h>
29#include <linux/idr.h>
Alexander Gordeev2a5cd6e2011-01-12 17:00:53 -080030#include <linux/mutex.h>
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -070031#include <linux/cdev.h>
32#include <linux/poll.h>
33#include <linux/pps_kernel.h>
Alexander Gordeev083e5862011-01-12 17:00:53 -080034#include <linux/slab.h>
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -070035
Alexander Gordeev717c0332011-01-12 17:00:58 -080036#include "kc.h"
37
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -070038/*
39 * Local variables
40 */
41
42static dev_t pps_devt;
43static struct class *pps_class;
44
Alexander Gordeev2a5cd6e2011-01-12 17:00:53 -080045static DEFINE_MUTEX(pps_idr_lock);
Alexander Gordeev083e5862011-01-12 17:00:53 -080046static DEFINE_IDR(pps_idr);
47
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -070048/*
49 * Char device methods
50 */
51
52static unsigned int pps_cdev_poll(struct file *file, poll_table *wait)
53{
54 struct pps_device *pps = file->private_data;
55
56 poll_wait(file, &pps->queue, wait);
57
58 return POLLIN | POLLRDNORM;
59}
60
61static int pps_cdev_fasync(int fd, struct file *file, int on)
62{
63 struct pps_device *pps = file->private_data;
64 return fasync_helper(fd, file, on, &pps->async_queue);
65}
66
67static long pps_cdev_ioctl(struct file *file,
68 unsigned int cmd, unsigned long arg)
69{
70 struct pps_device *pps = file->private_data;
71 struct pps_kparams params;
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -070072 void __user *uarg = (void __user *) arg;
73 int __user *iuarg = (int __user *) arg;
74 int err;
75
76 switch (cmd) {
77 case PPS_GETPARAMS:
Alexander Gordeev7f7cce72011-01-12 17:00:52 -080078 dev_dbg(pps->dev, "PPS_GETPARAMS\n");
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -070079
Rodolfo Giometticbf83cc52009-11-11 14:26:52 -080080 spin_lock_irq(&pps->lock);
81
82 /* Get the current parameters */
83 params = pps->params;
84
85 spin_unlock_irq(&pps->lock);
86
87 err = copy_to_user(uarg, &params, sizeof(struct pps_kparams));
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -070088 if (err)
89 return -EFAULT;
90
91 break;
92
93 case PPS_SETPARAMS:
Alexander Gordeev7f7cce72011-01-12 17:00:52 -080094 dev_dbg(pps->dev, "PPS_SETPARAMS\n");
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -070095
96 /* Check the capabilities */
97 if (!capable(CAP_SYS_TIME))
98 return -EPERM;
99
100 err = copy_from_user(&params, uarg, sizeof(struct pps_kparams));
101 if (err)
102 return -EFAULT;
103 if (!(params.mode & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR))) {
Alexander Gordeev7f7cce72011-01-12 17:00:52 -0800104 dev_dbg(pps->dev, "capture mode unspecified (%x)\n",
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700105 params.mode);
106 return -EINVAL;
107 }
108
109 /* Check for supported capabilities */
110 if ((params.mode & ~pps->info.mode) != 0) {
Alexander Gordeev7f7cce72011-01-12 17:00:52 -0800111 dev_dbg(pps->dev, "unsupported capabilities (%x)\n",
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700112 params.mode);
113 return -EINVAL;
114 }
115
116 spin_lock_irq(&pps->lock);
117
118 /* Save the new parameters */
119 pps->params = params;
120
121 /* Restore the read only parameters */
122 if ((params.mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) {
123 /* section 3.3 of RFC 2783 interpreted */
Alexander Gordeev7f7cce72011-01-12 17:00:52 -0800124 dev_dbg(pps->dev, "time format unspecified (%x)\n",
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700125 params.mode);
126 pps->params.mode |= PPS_TSFMT_TSPEC;
127 }
128 if (pps->info.mode & PPS_CANWAIT)
129 pps->params.mode |= PPS_CANWAIT;
130 pps->params.api_version = PPS_API_VERS;
131
132 spin_unlock_irq(&pps->lock);
133
134 break;
135
136 case PPS_GETCAP:
Alexander Gordeev7f7cce72011-01-12 17:00:52 -0800137 dev_dbg(pps->dev, "PPS_GETCAP\n");
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700138
139 err = put_user(pps->info.mode, iuarg);
140 if (err)
141 return -EFAULT;
142
143 break;
144
Alexander Gordeev86d921f2011-01-12 17:00:49 -0800145 case PPS_FETCH: {
146 struct pps_fdata fdata;
Alexander Gordeev3003d552011-01-12 17:00:50 -0800147 unsigned int ev;
Alexander Gordeev86d921f2011-01-12 17:00:49 -0800148
Alexander Gordeev7f7cce72011-01-12 17:00:52 -0800149 dev_dbg(pps->dev, "PPS_FETCH\n");
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700150
151 err = copy_from_user(&fdata, uarg, sizeof(struct pps_fdata));
152 if (err)
153 return -EFAULT;
154
Alexander Gordeev3003d552011-01-12 17:00:50 -0800155 ev = pps->last_ev;
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700156
157 /* Manage the timeout */
158 if (fdata.timeout.flags & PPS_TIME_INVALID)
Alexander Gordeev3003d552011-01-12 17:00:50 -0800159 err = wait_event_interruptible(pps->queue,
160 ev != pps->last_ev);
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700161 else {
Alexander Gordeev86d921f2011-01-12 17:00:49 -0800162 unsigned long ticks;
163
Alexander Gordeev7f7cce72011-01-12 17:00:52 -0800164 dev_dbg(pps->dev, "timeout %lld.%09d\n",
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700165 (long long) fdata.timeout.sec,
166 fdata.timeout.nsec);
167 ticks = fdata.timeout.sec * HZ;
168 ticks += fdata.timeout.nsec / (NSEC_PER_SEC / HZ);
169
170 if (ticks != 0) {
171 err = wait_event_interruptible_timeout(
Alexander Gordeev3003d552011-01-12 17:00:50 -0800172 pps->queue,
173 ev != pps->last_ev,
174 ticks);
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700175 if (err == 0)
176 return -ETIMEDOUT;
177 }
178 }
179
180 /* Check for pending signals */
181 if (err == -ERESTARTSYS) {
Alexander Gordeev7f7cce72011-01-12 17:00:52 -0800182 dev_dbg(pps->dev, "pending signal caught\n");
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700183 return -EINTR;
184 }
185
186 /* Return the fetched timestamp */
187 spin_lock_irq(&pps->lock);
188
189 fdata.info.assert_sequence = pps->assert_sequence;
190 fdata.info.clear_sequence = pps->clear_sequence;
191 fdata.info.assert_tu = pps->assert_tu;
192 fdata.info.clear_tu = pps->clear_tu;
193 fdata.info.current_mode = pps->current_mode;
194
195 spin_unlock_irq(&pps->lock);
196
197 err = copy_to_user(uarg, &fdata, sizeof(struct pps_fdata));
198 if (err)
199 return -EFAULT;
200
201 break;
Alexander Gordeev86d921f2011-01-12 17:00:49 -0800202 }
Alexander Gordeev717c0332011-01-12 17:00:58 -0800203 case PPS_KC_BIND: {
204 struct pps_bind_args bind_args;
205
206 dev_dbg(pps->dev, "PPS_KC_BIND\n");
207
208 /* Check the capabilities */
209 if (!capable(CAP_SYS_TIME))
210 return -EPERM;
211
212 if (copy_from_user(&bind_args, uarg,
213 sizeof(struct pps_bind_args)))
214 return -EFAULT;
215
216 /* Check for supported capabilities */
217 if ((bind_args.edge & ~pps->info.mode) != 0) {
218 dev_err(pps->dev, "unsupported capabilities (%x)\n",
219 bind_args.edge);
220 return -EINVAL;
221 }
222
223 /* Validate parameters roughly */
224 if (bind_args.tsformat != PPS_TSFMT_TSPEC ||
225 (bind_args.edge & ~PPS_CAPTUREBOTH) != 0 ||
226 bind_args.consumer != PPS_KC_HARDPPS) {
227 dev_err(pps->dev, "invalid kernel consumer bind"
228 " parameters (%x)\n", bind_args.edge);
229 return -EINVAL;
230 }
231
232 err = pps_kc_bind(pps, &bind_args);
233 if (err < 0)
234 return err;
235
236 break;
237 }
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700238 default:
239 return -ENOTTY;
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700240 }
241
242 return 0;
243}
244
245static int pps_cdev_open(struct inode *inode, struct file *file)
246{
247 struct pps_device *pps = container_of(inode->i_cdev,
248 struct pps_device, cdev);
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700249 file->private_data = pps;
George Spelvind953e0e2013-02-12 02:27:20 -0500250 kobject_get(&pps->dev->kobj);
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700251 return 0;
252}
253
254static int pps_cdev_release(struct inode *inode, struct file *file)
255{
George Spelvind953e0e2013-02-12 02:27:20 -0500256 struct pps_device *pps = container_of(inode->i_cdev,
257 struct pps_device, cdev);
258 kobject_put(&pps->dev->kobj);
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700259 return 0;
260}
261
262/*
263 * Char device stuff
264 */
265
266static const struct file_operations pps_cdev_fops = {
267 .owner = THIS_MODULE,
268 .llseek = no_llseek,
269 .poll = pps_cdev_poll,
270 .fasync = pps_cdev_fasync,
271 .unlocked_ioctl = pps_cdev_ioctl,
272 .open = pps_cdev_open,
273 .release = pps_cdev_release,
274};
275
Alexander Gordeev083e5862011-01-12 17:00:53 -0800276static void pps_device_destruct(struct device *dev)
277{
278 struct pps_device *pps = dev_get_drvdata(dev);
279
George Spelvind953e0e2013-02-12 02:27:20 -0500280 cdev_del(&pps->cdev);
281
282 /* Now we can release the ID for re-use */
283 pr_debug("deallocating pps%d\n", pps->id);
Alexander Gordeev2a5cd6e2011-01-12 17:00:53 -0800284 mutex_lock(&pps_idr_lock);
Alexander Gordeev083e5862011-01-12 17:00:53 -0800285 idr_remove(&pps_idr, pps->id);
Alexander Gordeev2a5cd6e2011-01-12 17:00:53 -0800286 mutex_unlock(&pps_idr_lock);
Alexander Gordeev083e5862011-01-12 17:00:53 -0800287
288 kfree(dev);
289 kfree(pps);
290}
291
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700292int pps_register_cdev(struct pps_device *pps)
293{
294 int err;
Alexander Gordeev5e196d32011-01-12 17:00:51 -0800295 dev_t devt;
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700296
Alexander Gordeev2a5cd6e2011-01-12 17:00:53 -0800297 mutex_lock(&pps_idr_lock);
Alexander Gordeev083e5862011-01-12 17:00:53 -0800298 /* Get new ID for the new PPS source */
Alexander Gordeev2a5cd6e2011-01-12 17:00:53 -0800299 if (idr_pre_get(&pps_idr, GFP_KERNEL) == 0) {
300 mutex_unlock(&pps_idr_lock);
Alexander Gordeev083e5862011-01-12 17:00:53 -0800301 return -ENOMEM;
Alexander Gordeev2a5cd6e2011-01-12 17:00:53 -0800302 }
Alexander Gordeev083e5862011-01-12 17:00:53 -0800303
304 /* Now really allocate the PPS source.
305 * After idr_get_new() calling the new source will be freely available
306 * into the kernel.
307 */
Alexander Gordeev083e5862011-01-12 17:00:53 -0800308 err = idr_get_new(&pps_idr, pps, &pps->id);
Alexander Gordeev2a5cd6e2011-01-12 17:00:53 -0800309 mutex_unlock(&pps_idr_lock);
Alexander Gordeev083e5862011-01-12 17:00:53 -0800310
311 if (err < 0)
312 return err;
313
Fengguang Wu125c4c72012-10-04 17:13:15 -0700314 pps->id &= MAX_IDR_MASK;
Alexander Gordeev083e5862011-01-12 17:00:53 -0800315 if (pps->id >= PPS_MAX_SOURCES) {
316 pr_err("%s: too many PPS sources in the system\n",
317 pps->info.name);
318 err = -EBUSY;
319 goto free_idr;
320 }
321
Alexander Gordeev5e196d32011-01-12 17:00:51 -0800322 devt = MKDEV(MAJOR(pps_devt), pps->id);
323
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700324 cdev_init(&pps->cdev, &pps_cdev_fops);
325 pps->cdev.owner = pps->info.owner;
326
Alexander Gordeev5e196d32011-01-12 17:00:51 -0800327 err = cdev_add(&pps->cdev, devt, 1);
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700328 if (err) {
Alexander Gordeev7f7cce72011-01-12 17:00:52 -0800329 pr_err("%s: failed to add char device %d:%d\n",
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700330 pps->info.name, MAJOR(pps_devt), pps->id);
Alexander Gordeev083e5862011-01-12 17:00:53 -0800331 goto free_idr;
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700332 }
Alexander Gordeev5e196d32011-01-12 17:00:51 -0800333 pps->dev = device_create(pps_class, pps->info.dev, devt, pps,
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700334 "pps%d", pps->id);
Emil Goode668f06b2012-07-30 14:42:51 -0700335 if (IS_ERR(pps->dev)) {
336 err = PTR_ERR(pps->dev);
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700337 goto del_cdev;
Emil Goode668f06b2012-07-30 14:42:51 -0700338 }
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700339
George Spelvind953e0e2013-02-12 02:27:20 -0500340 /* Override the release function with our own */
Alexander Gordeev083e5862011-01-12 17:00:53 -0800341 pps->dev->release = pps_device_destruct;
342
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700343 pr_debug("source %s got cdev (%d:%d)\n", pps->info.name,
344 MAJOR(pps_devt), pps->id);
345
346 return 0;
347
348del_cdev:
349 cdev_del(&pps->cdev);
350
Alexander Gordeev083e5862011-01-12 17:00:53 -0800351free_idr:
Alexander Gordeev2a5cd6e2011-01-12 17:00:53 -0800352 mutex_lock(&pps_idr_lock);
Alexander Gordeev083e5862011-01-12 17:00:53 -0800353 idr_remove(&pps_idr, pps->id);
Alexander Gordeev2a5cd6e2011-01-12 17:00:53 -0800354 mutex_unlock(&pps_idr_lock);
Alexander Gordeev083e5862011-01-12 17:00:53 -0800355
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700356 return err;
357}
358
359void pps_unregister_cdev(struct pps_device *pps)
360{
George Spelvind953e0e2013-02-12 02:27:20 -0500361 pr_debug("unregistering pps%d\n", pps->id);
George Spelvin513b0322013-02-10 04:08:32 -0500362 pps->lookup_cookie = NULL;
Alexander Gordeev5e196d32011-01-12 17:00:51 -0800363 device_destroy(pps_class, pps->dev->devt);
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700364}
365
366/*
George Spelvin513b0322013-02-10 04:08:32 -0500367 * Look up a pps device by magic cookie.
368 * The cookie is usually a pointer to some enclosing device, but this
369 * code doesn't care; you should never be dereferencing it.
370 *
371 * This is a bit of a kludge that is currently used only by the PPS
372 * serial line discipline. It may need to be tweaked when a second user
373 * is found.
374 *
375 * There is no function interface for setting the lookup_cookie field.
376 * It's initialized to NULL when the pps device is created, and if a
377 * client wants to use it, just fill it in afterward.
378 *
379 * The cookie is automatically set to NULL in pps_unregister_source()
380 * so that it will not be used again, even if the pps device cannot
381 * be removed from the idr due to pending references holding the minor
382 * number in use.
383 */
384struct pps_device *pps_lookup_dev(void const *cookie)
385{
386 struct pps_device *pps;
387 unsigned id;
388
389 rcu_read_lock();
390 idr_for_each_entry(&pps_idr, pps, id)
391 if (cookie == pps->lookup_cookie)
392 break;
393 rcu_read_unlock();
394 return pps;
395}
396EXPORT_SYMBOL(pps_lookup_dev);
397
398/*
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700399 * Module stuff
400 */
401
402static void __exit pps_exit(void)
403{
404 class_destroy(pps_class);
405 unregister_chrdev_region(pps_devt, PPS_MAX_SOURCES);
406}
407
408static int __init pps_init(void)
409{
410 int err;
411
412 pps_class = class_create(THIS_MODULE, "pps");
Dan Carpenter7ad12562012-03-05 14:59:15 -0800413 if (IS_ERR(pps_class)) {
Alexander Gordeev7f7cce72011-01-12 17:00:52 -0800414 pr_err("failed to allocate class\n");
Dan Carpenter7ad12562012-03-05 14:59:15 -0800415 return PTR_ERR(pps_class);
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700416 }
417 pps_class->dev_attrs = pps_attrs;
418
419 err = alloc_chrdev_region(&pps_devt, 0, PPS_MAX_SOURCES, "pps");
420 if (err < 0) {
Alexander Gordeev7f7cce72011-01-12 17:00:52 -0800421 pr_err("failed to allocate char device region\n");
Rodolfo Giomettieae9d2b2009-06-17 16:28:37 -0700422 goto remove_class;
423 }
424
425 pr_info("LinuxPPS API ver. %d registered\n", PPS_API_VERS);
426 pr_info("Software ver. %s - Copyright 2005-2007 Rodolfo Giometti "
427 "<giometti@linux.it>\n", PPS_VERSION);
428
429 return 0;
430
431remove_class:
432 class_destroy(pps_class);
433
434 return err;
435}
436
437subsys_initcall(pps_init);
438module_exit(pps_exit);
439
440MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>");
441MODULE_DESCRIPTION("LinuxPPS support (RFC 2783) - ver. " PPS_VERSION);
442MODULE_LICENSE("GPL");