xref: /linux/drivers/ptp/ptp_chardev.c (revision 0678df8271820bcf8fb4f877129f05d68a237de4)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * PTP 1588 clock support - character device implementation.
4  *
5  * Copyright (C) 2010 OMICRON electronics GmbH
6  */
7 #include <linux/module.h>
8 #include <linux/posix-clock.h>
9 #include <linux/poll.h>
10 #include <linux/sched.h>
11 #include <linux/slab.h>
12 #include <linux/timekeeping.h>
13 #include <linux/debugfs.h>
14 
15 #include <linux/nospec.h>
16 
17 #include "ptp_private.h"
18 
19 static int ptp_disable_pinfunc(struct ptp_clock_info *ops,
20 			       enum ptp_pin_function func, unsigned int chan)
21 {
22 	struct ptp_clock_request rq;
23 	int err = 0;
24 
25 	memset(&rq, 0, sizeof(rq));
26 
27 	switch (func) {
28 	case PTP_PF_NONE:
29 		break;
30 	case PTP_PF_EXTTS:
31 		rq.type = PTP_CLK_REQ_EXTTS;
32 		rq.extts.index = chan;
33 		err = ops->enable(ops, &rq, 0);
34 		break;
35 	case PTP_PF_PEROUT:
36 		rq.type = PTP_CLK_REQ_PEROUT;
37 		rq.perout.index = chan;
38 		err = ops->enable(ops, &rq, 0);
39 		break;
40 	case PTP_PF_PHYSYNC:
41 		break;
42 	default:
43 		return -EINVAL;
44 	}
45 
46 	return err;
47 }
48 
49 int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
50 		    enum ptp_pin_function func, unsigned int chan)
51 {
52 	struct ptp_clock_info *info = ptp->info;
53 	struct ptp_pin_desc *pin1 = NULL, *pin2 = &info->pin_config[pin];
54 	unsigned int i;
55 
56 	/* Check to see if any other pin previously had this function. */
57 	for (i = 0; i < info->n_pins; i++) {
58 		if (info->pin_config[i].func == func &&
59 		    info->pin_config[i].chan == chan) {
60 			pin1 = &info->pin_config[i];
61 			break;
62 		}
63 	}
64 	if (pin1 && i == pin)
65 		return 0;
66 
67 	/* Check the desired function and channel. */
68 	switch (func) {
69 	case PTP_PF_NONE:
70 		break;
71 	case PTP_PF_EXTTS:
72 		if (chan >= info->n_ext_ts)
73 			return -EINVAL;
74 		break;
75 	case PTP_PF_PEROUT:
76 		if (chan >= info->n_per_out)
77 			return -EINVAL;
78 		break;
79 	case PTP_PF_PHYSYNC:
80 		if (chan != 0)
81 			return -EINVAL;
82 		break;
83 	default:
84 		return -EINVAL;
85 	}
86 
87 	if (info->verify(info, pin, func, chan)) {
88 		pr_err("driver cannot use function %u on pin %u\n", func, chan);
89 		return -EOPNOTSUPP;
90 	}
91 
92 	/* Disable whatever function was previously assigned. */
93 	if (pin1) {
94 		ptp_disable_pinfunc(info, func, chan);
95 		pin1->func = PTP_PF_NONE;
96 		pin1->chan = 0;
97 	}
98 	ptp_disable_pinfunc(info, pin2->func, pin2->chan);
99 	pin2->func = func;
100 	pin2->chan = chan;
101 
102 	return 0;
103 }
104 
105 int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
106 {
107 	struct ptp_clock *ptp =
108 		container_of(pccontext->clk, struct ptp_clock, clock);
109 	struct timestamp_event_queue *queue;
110 	char debugfsname[32];
111 	unsigned long flags;
112 
113 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
114 	if (!queue)
115 		return -EINVAL;
116 	queue->mask = bitmap_alloc(PTP_MAX_CHANNELS, GFP_KERNEL);
117 	if (!queue->mask) {
118 		kfree(queue);
119 		return -EINVAL;
120 	}
121 	bitmap_set(queue->mask, 0, PTP_MAX_CHANNELS);
122 	spin_lock_init(&queue->lock);
123 	spin_lock_irqsave(&ptp->tsevqs_lock, flags);
124 	list_add_tail(&queue->qlist, &ptp->tsevqs);
125 	spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
126 	pccontext->private_clkdata = queue;
127 
128 	/* Debugfs contents */
129 	sprintf(debugfsname, "0x%p", queue);
130 	queue->debugfs_instance =
131 		debugfs_create_dir(debugfsname, ptp->debugfs_root);
132 	queue->dfs_bitmap.array = (u32 *)queue->mask;
133 	queue->dfs_bitmap.n_elements =
134 		DIV_ROUND_UP(PTP_MAX_CHANNELS, BITS_PER_BYTE * sizeof(u32));
135 	debugfs_create_u32_array("mask", 0444, queue->debugfs_instance,
136 				 &queue->dfs_bitmap);
137 
138 	return 0;
139 }
140 
141 int ptp_release(struct posix_clock_context *pccontext)
142 {
143 	struct timestamp_event_queue *queue = pccontext->private_clkdata;
144 	unsigned long flags;
145 	struct ptp_clock *ptp =
146 		container_of(pccontext->clk, struct ptp_clock, clock);
147 
148 	debugfs_remove(queue->debugfs_instance);
149 	pccontext->private_clkdata = NULL;
150 	spin_lock_irqsave(&ptp->tsevqs_lock, flags);
151 	list_del(&queue->qlist);
152 	spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
153 	bitmap_free(queue->mask);
154 	kfree(queue);
155 	return 0;
156 }
157 
158 long ptp_ioctl(struct posix_clock_context *pccontext, unsigned int cmd,
159 	       unsigned long arg)
160 {
161 	struct ptp_clock *ptp =
162 		container_of(pccontext->clk, struct ptp_clock, clock);
163 	struct ptp_sys_offset_extended *extoff = NULL;
164 	struct ptp_sys_offset_precise precise_offset;
165 	struct system_device_crosststamp xtstamp;
166 	struct ptp_clock_info *ops = ptp->info;
167 	struct ptp_sys_offset *sysoff = NULL;
168 	struct timestamp_event_queue *tsevq;
169 	struct ptp_system_timestamp sts;
170 	struct ptp_clock_request req;
171 	struct ptp_clock_caps caps;
172 	struct ptp_clock_time *pct;
173 	unsigned int i, pin_index;
174 	struct ptp_pin_desc pd;
175 	struct timespec64 ts;
176 	int enable, err = 0;
177 
178 	tsevq = pccontext->private_clkdata;
179 
180 	switch (cmd) {
181 
182 	case PTP_CLOCK_GETCAPS:
183 	case PTP_CLOCK_GETCAPS2:
184 		memset(&caps, 0, sizeof(caps));
185 
186 		caps.max_adj = ptp->info->max_adj;
187 		caps.n_alarm = ptp->info->n_alarm;
188 		caps.n_ext_ts = ptp->info->n_ext_ts;
189 		caps.n_per_out = ptp->info->n_per_out;
190 		caps.pps = ptp->info->pps;
191 		caps.n_pins = ptp->info->n_pins;
192 		caps.cross_timestamping = ptp->info->getcrosststamp != NULL;
193 		caps.adjust_phase = ptp->info->adjphase != NULL &&
194 				    ptp->info->getmaxphase != NULL;
195 		if (caps.adjust_phase)
196 			caps.max_phase_adj = ptp->info->getmaxphase(ptp->info);
197 		if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
198 			err = -EFAULT;
199 		break;
200 
201 	case PTP_EXTTS_REQUEST:
202 	case PTP_EXTTS_REQUEST2:
203 		memset(&req, 0, sizeof(req));
204 
205 		if (copy_from_user(&req.extts, (void __user *)arg,
206 				   sizeof(req.extts))) {
207 			err = -EFAULT;
208 			break;
209 		}
210 		if (cmd == PTP_EXTTS_REQUEST2) {
211 			/* Tell the drivers to check the flags carefully. */
212 			req.extts.flags |= PTP_STRICT_FLAGS;
213 			/* Make sure no reserved bit is set. */
214 			if ((req.extts.flags & ~PTP_EXTTS_VALID_FLAGS) ||
215 			    req.extts.rsv[0] || req.extts.rsv[1]) {
216 				err = -EINVAL;
217 				break;
218 			}
219 			/* Ensure one of the rising/falling edge bits is set. */
220 			if ((req.extts.flags & PTP_ENABLE_FEATURE) &&
221 			    (req.extts.flags & PTP_EXTTS_EDGES) == 0) {
222 				err = -EINVAL;
223 				break;
224 			}
225 		} else if (cmd == PTP_EXTTS_REQUEST) {
226 			req.extts.flags &= PTP_EXTTS_V1_VALID_FLAGS;
227 			req.extts.rsv[0] = 0;
228 			req.extts.rsv[1] = 0;
229 		}
230 		if (req.extts.index >= ops->n_ext_ts) {
231 			err = -EINVAL;
232 			break;
233 		}
234 		req.type = PTP_CLK_REQ_EXTTS;
235 		enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
236 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
237 			return -ERESTARTSYS;
238 		err = ops->enable(ops, &req, enable);
239 		mutex_unlock(&ptp->pincfg_mux);
240 		break;
241 
242 	case PTP_PEROUT_REQUEST:
243 	case PTP_PEROUT_REQUEST2:
244 		memset(&req, 0, sizeof(req));
245 
246 		if (copy_from_user(&req.perout, (void __user *)arg,
247 				   sizeof(req.perout))) {
248 			err = -EFAULT;
249 			break;
250 		}
251 		if (cmd == PTP_PEROUT_REQUEST2) {
252 			struct ptp_perout_request *perout = &req.perout;
253 
254 			if (perout->flags & ~PTP_PEROUT_VALID_FLAGS) {
255 				err = -EINVAL;
256 				break;
257 			}
258 			/*
259 			 * The "on" field has undefined meaning if
260 			 * PTP_PEROUT_DUTY_CYCLE isn't set, we must still treat
261 			 * it as reserved, which must be set to zero.
262 			 */
263 			if (!(perout->flags & PTP_PEROUT_DUTY_CYCLE) &&
264 			    (perout->rsv[0] || perout->rsv[1] ||
265 			     perout->rsv[2] || perout->rsv[3])) {
266 				err = -EINVAL;
267 				break;
268 			}
269 			if (perout->flags & PTP_PEROUT_DUTY_CYCLE) {
270 				/* The duty cycle must be subunitary. */
271 				if (perout->on.sec > perout->period.sec ||
272 				    (perout->on.sec == perout->period.sec &&
273 				     perout->on.nsec > perout->period.nsec)) {
274 					err = -ERANGE;
275 					break;
276 				}
277 			}
278 			if (perout->flags & PTP_PEROUT_PHASE) {
279 				/*
280 				 * The phase should be specified modulo the
281 				 * period, therefore anything equal or larger
282 				 * than 1 period is invalid.
283 				 */
284 				if (perout->phase.sec > perout->period.sec ||
285 				    (perout->phase.sec == perout->period.sec &&
286 				     perout->phase.nsec >= perout->period.nsec)) {
287 					err = -ERANGE;
288 					break;
289 				}
290 			}
291 		} else if (cmd == PTP_PEROUT_REQUEST) {
292 			req.perout.flags &= PTP_PEROUT_V1_VALID_FLAGS;
293 			req.perout.rsv[0] = 0;
294 			req.perout.rsv[1] = 0;
295 			req.perout.rsv[2] = 0;
296 			req.perout.rsv[3] = 0;
297 		}
298 		if (req.perout.index >= ops->n_per_out) {
299 			err = -EINVAL;
300 			break;
301 		}
302 		req.type = PTP_CLK_REQ_PEROUT;
303 		enable = req.perout.period.sec || req.perout.period.nsec;
304 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
305 			return -ERESTARTSYS;
306 		err = ops->enable(ops, &req, enable);
307 		mutex_unlock(&ptp->pincfg_mux);
308 		break;
309 
310 	case PTP_ENABLE_PPS:
311 	case PTP_ENABLE_PPS2:
312 		memset(&req, 0, sizeof(req));
313 
314 		if (!capable(CAP_SYS_TIME))
315 			return -EPERM;
316 		req.type = PTP_CLK_REQ_PPS;
317 		enable = arg ? 1 : 0;
318 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
319 			return -ERESTARTSYS;
320 		err = ops->enable(ops, &req, enable);
321 		mutex_unlock(&ptp->pincfg_mux);
322 		break;
323 
324 	case PTP_SYS_OFFSET_PRECISE:
325 	case PTP_SYS_OFFSET_PRECISE2:
326 		if (!ptp->info->getcrosststamp) {
327 			err = -EOPNOTSUPP;
328 			break;
329 		}
330 		err = ptp->info->getcrosststamp(ptp->info, &xtstamp);
331 		if (err)
332 			break;
333 
334 		memset(&precise_offset, 0, sizeof(precise_offset));
335 		ts = ktime_to_timespec64(xtstamp.device);
336 		precise_offset.device.sec = ts.tv_sec;
337 		precise_offset.device.nsec = ts.tv_nsec;
338 		ts = ktime_to_timespec64(xtstamp.sys_realtime);
339 		precise_offset.sys_realtime.sec = ts.tv_sec;
340 		precise_offset.sys_realtime.nsec = ts.tv_nsec;
341 		ts = ktime_to_timespec64(xtstamp.sys_monoraw);
342 		precise_offset.sys_monoraw.sec = ts.tv_sec;
343 		precise_offset.sys_monoraw.nsec = ts.tv_nsec;
344 		if (copy_to_user((void __user *)arg, &precise_offset,
345 				 sizeof(precise_offset)))
346 			err = -EFAULT;
347 		break;
348 
349 	case PTP_SYS_OFFSET_EXTENDED:
350 	case PTP_SYS_OFFSET_EXTENDED2:
351 		if (!ptp->info->gettimex64) {
352 			err = -EOPNOTSUPP;
353 			break;
354 		}
355 		extoff = memdup_user((void __user *)arg, sizeof(*extoff));
356 		if (IS_ERR(extoff)) {
357 			err = PTR_ERR(extoff);
358 			extoff = NULL;
359 			break;
360 		}
361 		if (extoff->n_samples > PTP_MAX_SAMPLES
362 		    || extoff->rsv[0] || extoff->rsv[1] || extoff->rsv[2]) {
363 			err = -EINVAL;
364 			break;
365 		}
366 		for (i = 0; i < extoff->n_samples; i++) {
367 			err = ptp->info->gettimex64(ptp->info, &ts, &sts);
368 			if (err)
369 				goto out;
370 			extoff->ts[i][0].sec = sts.pre_ts.tv_sec;
371 			extoff->ts[i][0].nsec = sts.pre_ts.tv_nsec;
372 			extoff->ts[i][1].sec = ts.tv_sec;
373 			extoff->ts[i][1].nsec = ts.tv_nsec;
374 			extoff->ts[i][2].sec = sts.post_ts.tv_sec;
375 			extoff->ts[i][2].nsec = sts.post_ts.tv_nsec;
376 		}
377 		if (copy_to_user((void __user *)arg, extoff, sizeof(*extoff)))
378 			err = -EFAULT;
379 		break;
380 
381 	case PTP_SYS_OFFSET:
382 	case PTP_SYS_OFFSET2:
383 		sysoff = memdup_user((void __user *)arg, sizeof(*sysoff));
384 		if (IS_ERR(sysoff)) {
385 			err = PTR_ERR(sysoff);
386 			sysoff = NULL;
387 			break;
388 		}
389 		if (sysoff->n_samples > PTP_MAX_SAMPLES) {
390 			err = -EINVAL;
391 			break;
392 		}
393 		pct = &sysoff->ts[0];
394 		for (i = 0; i < sysoff->n_samples; i++) {
395 			ktime_get_real_ts64(&ts);
396 			pct->sec = ts.tv_sec;
397 			pct->nsec = ts.tv_nsec;
398 			pct++;
399 			if (ops->gettimex64)
400 				err = ops->gettimex64(ops, &ts, NULL);
401 			else
402 				err = ops->gettime64(ops, &ts);
403 			if (err)
404 				goto out;
405 			pct->sec = ts.tv_sec;
406 			pct->nsec = ts.tv_nsec;
407 			pct++;
408 		}
409 		ktime_get_real_ts64(&ts);
410 		pct->sec = ts.tv_sec;
411 		pct->nsec = ts.tv_nsec;
412 		if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff)))
413 			err = -EFAULT;
414 		break;
415 
416 	case PTP_PIN_GETFUNC:
417 	case PTP_PIN_GETFUNC2:
418 		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
419 			err = -EFAULT;
420 			break;
421 		}
422 		if ((pd.rsv[0] || pd.rsv[1] || pd.rsv[2]
423 				|| pd.rsv[3] || pd.rsv[4])
424 			&& cmd == PTP_PIN_GETFUNC2) {
425 			err = -EINVAL;
426 			break;
427 		} else if (cmd == PTP_PIN_GETFUNC) {
428 			pd.rsv[0] = 0;
429 			pd.rsv[1] = 0;
430 			pd.rsv[2] = 0;
431 			pd.rsv[3] = 0;
432 			pd.rsv[4] = 0;
433 		}
434 		pin_index = pd.index;
435 		if (pin_index >= ops->n_pins) {
436 			err = -EINVAL;
437 			break;
438 		}
439 		pin_index = array_index_nospec(pin_index, ops->n_pins);
440 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
441 			return -ERESTARTSYS;
442 		pd = ops->pin_config[pin_index];
443 		mutex_unlock(&ptp->pincfg_mux);
444 		if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
445 			err = -EFAULT;
446 		break;
447 
448 	case PTP_PIN_SETFUNC:
449 	case PTP_PIN_SETFUNC2:
450 		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
451 			err = -EFAULT;
452 			break;
453 		}
454 		if ((pd.rsv[0] || pd.rsv[1] || pd.rsv[2]
455 				|| pd.rsv[3] || pd.rsv[4])
456 			&& cmd == PTP_PIN_SETFUNC2) {
457 			err = -EINVAL;
458 			break;
459 		} else if (cmd == PTP_PIN_SETFUNC) {
460 			pd.rsv[0] = 0;
461 			pd.rsv[1] = 0;
462 			pd.rsv[2] = 0;
463 			pd.rsv[3] = 0;
464 			pd.rsv[4] = 0;
465 		}
466 		pin_index = pd.index;
467 		if (pin_index >= ops->n_pins) {
468 			err = -EINVAL;
469 			break;
470 		}
471 		pin_index = array_index_nospec(pin_index, ops->n_pins);
472 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
473 			return -ERESTARTSYS;
474 		err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
475 		mutex_unlock(&ptp->pincfg_mux);
476 		break;
477 
478 	case PTP_MASK_CLEAR_ALL:
479 		bitmap_clear(tsevq->mask, 0, PTP_MAX_CHANNELS);
480 		break;
481 
482 	case PTP_MASK_EN_SINGLE:
483 		if (copy_from_user(&i, (void __user *)arg, sizeof(i))) {
484 			err = -EFAULT;
485 			break;
486 		}
487 		if (i >= PTP_MAX_CHANNELS) {
488 			err = -EFAULT;
489 			break;
490 		}
491 		set_bit(i, tsevq->mask);
492 		break;
493 
494 	default:
495 		err = -ENOTTY;
496 		break;
497 	}
498 
499 out:
500 	kfree(extoff);
501 	kfree(sysoff);
502 	return err;
503 }
504 
505 __poll_t ptp_poll(struct posix_clock_context *pccontext, struct file *fp,
506 		  poll_table *wait)
507 {
508 	struct ptp_clock *ptp =
509 		container_of(pccontext->clk, struct ptp_clock, clock);
510 	struct timestamp_event_queue *queue;
511 
512 	queue = pccontext->private_clkdata;
513 	if (!queue)
514 		return EPOLLERR;
515 
516 	poll_wait(fp, &ptp->tsev_wq, wait);
517 
518 	return queue_cnt(queue) ? EPOLLIN : 0;
519 }
520 
521 #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
522 
523 ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags,
524 		 char __user *buf, size_t cnt)
525 {
526 	struct ptp_clock *ptp =
527 		container_of(pccontext->clk, struct ptp_clock, clock);
528 	struct timestamp_event_queue *queue;
529 	struct ptp_extts_event *event;
530 	unsigned long flags;
531 	size_t qcnt, i;
532 	int result;
533 
534 	queue = pccontext->private_clkdata;
535 	if (!queue) {
536 		result = -EINVAL;
537 		goto exit;
538 	}
539 
540 	if (cnt % sizeof(struct ptp_extts_event) != 0) {
541 		result = -EINVAL;
542 		goto exit;
543 	}
544 
545 	if (cnt > EXTTS_BUFSIZE)
546 		cnt = EXTTS_BUFSIZE;
547 
548 	cnt = cnt / sizeof(struct ptp_extts_event);
549 
550 	if (wait_event_interruptible(ptp->tsev_wq,
551 				     ptp->defunct || queue_cnt(queue))) {
552 		return -ERESTARTSYS;
553 	}
554 
555 	if (ptp->defunct) {
556 		result = -ENODEV;
557 		goto exit;
558 	}
559 
560 	event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
561 	if (!event) {
562 		result = -ENOMEM;
563 		goto exit;
564 	}
565 
566 	spin_lock_irqsave(&queue->lock, flags);
567 
568 	qcnt = queue_cnt(queue);
569 
570 	if (cnt > qcnt)
571 		cnt = qcnt;
572 
573 	for (i = 0; i < cnt; i++) {
574 		event[i] = queue->buf[queue->head];
575 		queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
576 	}
577 
578 	spin_unlock_irqrestore(&queue->lock, flags);
579 
580 	cnt = cnt * sizeof(struct ptp_extts_event);
581 
582 	result = cnt;
583 	if (copy_to_user(buf, event, cnt)) {
584 		result = -EFAULT;
585 		goto free_event;
586 	}
587 
588 free_event:
589 	kfree(event);
590 exit:
591 	return result;
592 }
593