xref: /linux/drivers/ptp/ptp_chardev.c (revision d99ff463ecf651437e9e4abe68f331dfb6b5bd9d)
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 
14 #include <linux/nospec.h>
15 
16 #include "ptp_private.h"
17 
18 static int ptp_disable_pinfunc(struct ptp_clock_info *ops,
19 			       enum ptp_pin_function func, unsigned int chan)
20 {
21 	struct ptp_clock_request rq;
22 	int err = 0;
23 
24 	memset(&rq, 0, sizeof(rq));
25 
26 	switch (func) {
27 	case PTP_PF_NONE:
28 		break;
29 	case PTP_PF_EXTTS:
30 		rq.type = PTP_CLK_REQ_EXTTS;
31 		rq.extts.index = chan;
32 		err = ops->enable(ops, &rq, 0);
33 		break;
34 	case PTP_PF_PEROUT:
35 		rq.type = PTP_CLK_REQ_PEROUT;
36 		rq.perout.index = chan;
37 		err = ops->enable(ops, &rq, 0);
38 		break;
39 	case PTP_PF_PHYSYNC:
40 		break;
41 	default:
42 		return -EINVAL;
43 	}
44 
45 	return err;
46 }
47 
48 int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
49 		    enum ptp_pin_function func, unsigned int chan)
50 {
51 	struct ptp_clock_info *info = ptp->info;
52 	struct ptp_pin_desc *pin1 = NULL, *pin2 = &info->pin_config[pin];
53 	unsigned int i;
54 
55 	/* Check to see if any other pin previously had this function. */
56 	for (i = 0; i < info->n_pins; i++) {
57 		if (info->pin_config[i].func == func &&
58 		    info->pin_config[i].chan == chan) {
59 			pin1 = &info->pin_config[i];
60 			break;
61 		}
62 	}
63 	if (pin1 && i == pin)
64 		return 0;
65 
66 	/* Check the desired function and channel. */
67 	switch (func) {
68 	case PTP_PF_NONE:
69 		break;
70 	case PTP_PF_EXTTS:
71 		if (chan >= info->n_ext_ts)
72 			return -EINVAL;
73 		break;
74 	case PTP_PF_PEROUT:
75 		if (chan >= info->n_per_out)
76 			return -EINVAL;
77 		break;
78 	case PTP_PF_PHYSYNC:
79 		if (chan != 0)
80 			return -EINVAL;
81 		break;
82 	default:
83 		return -EINVAL;
84 	}
85 
86 	if (info->verify(info, pin, func, chan)) {
87 		pr_err("driver cannot use function %u on pin %u\n", func, chan);
88 		return -EOPNOTSUPP;
89 	}
90 
91 	/* Disable whatever function was previously assigned. */
92 	if (pin1) {
93 		ptp_disable_pinfunc(info, func, chan);
94 		pin1->func = PTP_PF_NONE;
95 		pin1->chan = 0;
96 	}
97 	ptp_disable_pinfunc(info, pin2->func, pin2->chan);
98 	pin2->func = func;
99 	pin2->chan = chan;
100 
101 	return 0;
102 }
103 
104 int ptp_open(struct posix_clock *pc, fmode_t fmode)
105 {
106 	return 0;
107 }
108 
109 long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
110 {
111 	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
112 	struct ptp_sys_offset_extended *extoff = NULL;
113 	struct ptp_sys_offset_precise precise_offset;
114 	struct system_device_crosststamp xtstamp;
115 	struct ptp_clock_info *ops = ptp->info;
116 	struct ptp_sys_offset *sysoff = NULL;
117 	struct ptp_system_timestamp sts;
118 	struct ptp_clock_request req;
119 	struct ptp_clock_caps caps;
120 	struct ptp_clock_time *pct;
121 	unsigned int i, pin_index;
122 	struct ptp_pin_desc pd;
123 	struct timespec64 ts;
124 	int enable, err = 0;
125 
126 	switch (cmd) {
127 
128 	case PTP_CLOCK_GETCAPS:
129 	case PTP_CLOCK_GETCAPS2:
130 		memset(&caps, 0, sizeof(caps));
131 
132 		caps.max_adj = ptp->info->max_adj;
133 		caps.n_alarm = ptp->info->n_alarm;
134 		caps.n_ext_ts = ptp->info->n_ext_ts;
135 		caps.n_per_out = ptp->info->n_per_out;
136 		caps.pps = ptp->info->pps;
137 		caps.n_pins = ptp->info->n_pins;
138 		caps.cross_timestamping = ptp->info->getcrosststamp != NULL;
139 		caps.adjust_phase = ptp->info->adjphase != NULL &&
140 				    ptp->info->getmaxphase != NULL;
141 		if (caps.adjust_phase)
142 			caps.max_phase_adj = ptp->info->getmaxphase(ptp->info);
143 		if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
144 			err = -EFAULT;
145 		break;
146 
147 	case PTP_EXTTS_REQUEST:
148 	case PTP_EXTTS_REQUEST2:
149 		memset(&req, 0, sizeof(req));
150 
151 		if (copy_from_user(&req.extts, (void __user *)arg,
152 				   sizeof(req.extts))) {
153 			err = -EFAULT;
154 			break;
155 		}
156 		if (cmd == PTP_EXTTS_REQUEST2) {
157 			/* Tell the drivers to check the flags carefully. */
158 			req.extts.flags |= PTP_STRICT_FLAGS;
159 			/* Make sure no reserved bit is set. */
160 			if ((req.extts.flags & ~PTP_EXTTS_VALID_FLAGS) ||
161 			    req.extts.rsv[0] || req.extts.rsv[1]) {
162 				err = -EINVAL;
163 				break;
164 			}
165 			/* Ensure one of the rising/falling edge bits is set. */
166 			if ((req.extts.flags & PTP_ENABLE_FEATURE) &&
167 			    (req.extts.flags & PTP_EXTTS_EDGES) == 0) {
168 				err = -EINVAL;
169 				break;
170 			}
171 		} else if (cmd == PTP_EXTTS_REQUEST) {
172 			req.extts.flags &= PTP_EXTTS_V1_VALID_FLAGS;
173 			req.extts.rsv[0] = 0;
174 			req.extts.rsv[1] = 0;
175 		}
176 		if (req.extts.index >= ops->n_ext_ts) {
177 			err = -EINVAL;
178 			break;
179 		}
180 		req.type = PTP_CLK_REQ_EXTTS;
181 		enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
182 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
183 			return -ERESTARTSYS;
184 		err = ops->enable(ops, &req, enable);
185 		mutex_unlock(&ptp->pincfg_mux);
186 		break;
187 
188 	case PTP_PEROUT_REQUEST:
189 	case PTP_PEROUT_REQUEST2:
190 		memset(&req, 0, sizeof(req));
191 
192 		if (copy_from_user(&req.perout, (void __user *)arg,
193 				   sizeof(req.perout))) {
194 			err = -EFAULT;
195 			break;
196 		}
197 		if (cmd == PTP_PEROUT_REQUEST2) {
198 			struct ptp_perout_request *perout = &req.perout;
199 
200 			if (perout->flags & ~PTP_PEROUT_VALID_FLAGS) {
201 				err = -EINVAL;
202 				break;
203 			}
204 			/*
205 			 * The "on" field has undefined meaning if
206 			 * PTP_PEROUT_DUTY_CYCLE isn't set, we must still treat
207 			 * it as reserved, which must be set to zero.
208 			 */
209 			if (!(perout->flags & PTP_PEROUT_DUTY_CYCLE) &&
210 			    (perout->rsv[0] || perout->rsv[1] ||
211 			     perout->rsv[2] || perout->rsv[3])) {
212 				err = -EINVAL;
213 				break;
214 			}
215 			if (perout->flags & PTP_PEROUT_DUTY_CYCLE) {
216 				/* The duty cycle must be subunitary. */
217 				if (perout->on.sec > perout->period.sec ||
218 				    (perout->on.sec == perout->period.sec &&
219 				     perout->on.nsec > perout->period.nsec)) {
220 					err = -ERANGE;
221 					break;
222 				}
223 			}
224 			if (perout->flags & PTP_PEROUT_PHASE) {
225 				/*
226 				 * The phase should be specified modulo the
227 				 * period, therefore anything equal or larger
228 				 * than 1 period is invalid.
229 				 */
230 				if (perout->phase.sec > perout->period.sec ||
231 				    (perout->phase.sec == perout->period.sec &&
232 				     perout->phase.nsec >= perout->period.nsec)) {
233 					err = -ERANGE;
234 					break;
235 				}
236 			}
237 		} else if (cmd == PTP_PEROUT_REQUEST) {
238 			req.perout.flags &= PTP_PEROUT_V1_VALID_FLAGS;
239 			req.perout.rsv[0] = 0;
240 			req.perout.rsv[1] = 0;
241 			req.perout.rsv[2] = 0;
242 			req.perout.rsv[3] = 0;
243 		}
244 		if (req.perout.index >= ops->n_per_out) {
245 			err = -EINVAL;
246 			break;
247 		}
248 		req.type = PTP_CLK_REQ_PEROUT;
249 		enable = req.perout.period.sec || req.perout.period.nsec;
250 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
251 			return -ERESTARTSYS;
252 		err = ops->enable(ops, &req, enable);
253 		mutex_unlock(&ptp->pincfg_mux);
254 		break;
255 
256 	case PTP_ENABLE_PPS:
257 	case PTP_ENABLE_PPS2:
258 		memset(&req, 0, sizeof(req));
259 
260 		if (!capable(CAP_SYS_TIME))
261 			return -EPERM;
262 		req.type = PTP_CLK_REQ_PPS;
263 		enable = arg ? 1 : 0;
264 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
265 			return -ERESTARTSYS;
266 		err = ops->enable(ops, &req, enable);
267 		mutex_unlock(&ptp->pincfg_mux);
268 		break;
269 
270 	case PTP_SYS_OFFSET_PRECISE:
271 	case PTP_SYS_OFFSET_PRECISE2:
272 		if (!ptp->info->getcrosststamp) {
273 			err = -EOPNOTSUPP;
274 			break;
275 		}
276 		err = ptp->info->getcrosststamp(ptp->info, &xtstamp);
277 		if (err)
278 			break;
279 
280 		memset(&precise_offset, 0, sizeof(precise_offset));
281 		ts = ktime_to_timespec64(xtstamp.device);
282 		precise_offset.device.sec = ts.tv_sec;
283 		precise_offset.device.nsec = ts.tv_nsec;
284 		ts = ktime_to_timespec64(xtstamp.sys_realtime);
285 		precise_offset.sys_realtime.sec = ts.tv_sec;
286 		precise_offset.sys_realtime.nsec = ts.tv_nsec;
287 		ts = ktime_to_timespec64(xtstamp.sys_monoraw);
288 		precise_offset.sys_monoraw.sec = ts.tv_sec;
289 		precise_offset.sys_monoraw.nsec = ts.tv_nsec;
290 		if (copy_to_user((void __user *)arg, &precise_offset,
291 				 sizeof(precise_offset)))
292 			err = -EFAULT;
293 		break;
294 
295 	case PTP_SYS_OFFSET_EXTENDED:
296 	case PTP_SYS_OFFSET_EXTENDED2:
297 		if (!ptp->info->gettimex64) {
298 			err = -EOPNOTSUPP;
299 			break;
300 		}
301 		extoff = memdup_user((void __user *)arg, sizeof(*extoff));
302 		if (IS_ERR(extoff)) {
303 			err = PTR_ERR(extoff);
304 			extoff = NULL;
305 			break;
306 		}
307 		if (extoff->n_samples > PTP_MAX_SAMPLES
308 		    || extoff->rsv[0] || extoff->rsv[1] || extoff->rsv[2]) {
309 			err = -EINVAL;
310 			break;
311 		}
312 		for (i = 0; i < extoff->n_samples; i++) {
313 			err = ptp->info->gettimex64(ptp->info, &ts, &sts);
314 			if (err)
315 				goto out;
316 			extoff->ts[i][0].sec = sts.pre_ts.tv_sec;
317 			extoff->ts[i][0].nsec = sts.pre_ts.tv_nsec;
318 			extoff->ts[i][1].sec = ts.tv_sec;
319 			extoff->ts[i][1].nsec = ts.tv_nsec;
320 			extoff->ts[i][2].sec = sts.post_ts.tv_sec;
321 			extoff->ts[i][2].nsec = sts.post_ts.tv_nsec;
322 		}
323 		if (copy_to_user((void __user *)arg, extoff, sizeof(*extoff)))
324 			err = -EFAULT;
325 		break;
326 
327 	case PTP_SYS_OFFSET:
328 	case PTP_SYS_OFFSET2:
329 		sysoff = memdup_user((void __user *)arg, sizeof(*sysoff));
330 		if (IS_ERR(sysoff)) {
331 			err = PTR_ERR(sysoff);
332 			sysoff = NULL;
333 			break;
334 		}
335 		if (sysoff->n_samples > PTP_MAX_SAMPLES) {
336 			err = -EINVAL;
337 			break;
338 		}
339 		pct = &sysoff->ts[0];
340 		for (i = 0; i < sysoff->n_samples; i++) {
341 			ktime_get_real_ts64(&ts);
342 			pct->sec = ts.tv_sec;
343 			pct->nsec = ts.tv_nsec;
344 			pct++;
345 			if (ops->gettimex64)
346 				err = ops->gettimex64(ops, &ts, NULL);
347 			else
348 				err = ops->gettime64(ops, &ts);
349 			if (err)
350 				goto out;
351 			pct->sec = ts.tv_sec;
352 			pct->nsec = ts.tv_nsec;
353 			pct++;
354 		}
355 		ktime_get_real_ts64(&ts);
356 		pct->sec = ts.tv_sec;
357 		pct->nsec = ts.tv_nsec;
358 		if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff)))
359 			err = -EFAULT;
360 		break;
361 
362 	case PTP_PIN_GETFUNC:
363 	case PTP_PIN_GETFUNC2:
364 		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
365 			err = -EFAULT;
366 			break;
367 		}
368 		if ((pd.rsv[0] || pd.rsv[1] || pd.rsv[2]
369 				|| pd.rsv[3] || pd.rsv[4])
370 			&& cmd == PTP_PIN_GETFUNC2) {
371 			err = -EINVAL;
372 			break;
373 		} else if (cmd == PTP_PIN_GETFUNC) {
374 			pd.rsv[0] = 0;
375 			pd.rsv[1] = 0;
376 			pd.rsv[2] = 0;
377 			pd.rsv[3] = 0;
378 			pd.rsv[4] = 0;
379 		}
380 		pin_index = pd.index;
381 		if (pin_index >= ops->n_pins) {
382 			err = -EINVAL;
383 			break;
384 		}
385 		pin_index = array_index_nospec(pin_index, ops->n_pins);
386 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
387 			return -ERESTARTSYS;
388 		pd = ops->pin_config[pin_index];
389 		mutex_unlock(&ptp->pincfg_mux);
390 		if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
391 			err = -EFAULT;
392 		break;
393 
394 	case PTP_PIN_SETFUNC:
395 	case PTP_PIN_SETFUNC2:
396 		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
397 			err = -EFAULT;
398 			break;
399 		}
400 		if ((pd.rsv[0] || pd.rsv[1] || pd.rsv[2]
401 				|| pd.rsv[3] || pd.rsv[4])
402 			&& cmd == PTP_PIN_SETFUNC2) {
403 			err = -EINVAL;
404 			break;
405 		} else if (cmd == PTP_PIN_SETFUNC) {
406 			pd.rsv[0] = 0;
407 			pd.rsv[1] = 0;
408 			pd.rsv[2] = 0;
409 			pd.rsv[3] = 0;
410 			pd.rsv[4] = 0;
411 		}
412 		pin_index = pd.index;
413 		if (pin_index >= ops->n_pins) {
414 			err = -EINVAL;
415 			break;
416 		}
417 		pin_index = array_index_nospec(pin_index, ops->n_pins);
418 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
419 			return -ERESTARTSYS;
420 		err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
421 		mutex_unlock(&ptp->pincfg_mux);
422 		break;
423 
424 	default:
425 		err = -ENOTTY;
426 		break;
427 	}
428 
429 out:
430 	kfree(extoff);
431 	kfree(sysoff);
432 	return err;
433 }
434 
435 __poll_t ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
436 {
437 	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
438 
439 	poll_wait(fp, &ptp->tsev_wq, wait);
440 
441 	return queue_cnt(&ptp->tsevq) ? EPOLLIN : 0;
442 }
443 
444 #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
445 
446 ssize_t ptp_read(struct posix_clock *pc,
447 		 uint rdflags, char __user *buf, size_t cnt)
448 {
449 	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
450 	struct timestamp_event_queue *queue = &ptp->tsevq;
451 	struct ptp_extts_event *event;
452 	unsigned long flags;
453 	size_t qcnt, i;
454 	int result;
455 
456 	if (cnt % sizeof(struct ptp_extts_event) != 0)
457 		return -EINVAL;
458 
459 	if (cnt > EXTTS_BUFSIZE)
460 		cnt = EXTTS_BUFSIZE;
461 
462 	cnt = cnt / sizeof(struct ptp_extts_event);
463 
464 	if (mutex_lock_interruptible(&ptp->tsevq_mux))
465 		return -ERESTARTSYS;
466 
467 	if (wait_event_interruptible(ptp->tsev_wq,
468 				     ptp->defunct || queue_cnt(queue))) {
469 		mutex_unlock(&ptp->tsevq_mux);
470 		return -ERESTARTSYS;
471 	}
472 
473 	if (ptp->defunct) {
474 		mutex_unlock(&ptp->tsevq_mux);
475 		return -ENODEV;
476 	}
477 
478 	event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
479 	if (!event) {
480 		mutex_unlock(&ptp->tsevq_mux);
481 		return -ENOMEM;
482 	}
483 
484 	spin_lock_irqsave(&queue->lock, flags);
485 
486 	qcnt = queue_cnt(queue);
487 
488 	if (cnt > qcnt)
489 		cnt = qcnt;
490 
491 	for (i = 0; i < cnt; i++) {
492 		event[i] = queue->buf[queue->head];
493 		queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
494 	}
495 
496 	spin_unlock_irqrestore(&queue->lock, flags);
497 
498 	cnt = cnt * sizeof(struct ptp_extts_event);
499 
500 	mutex_unlock(&ptp->tsevq_mux);
501 
502 	result = cnt;
503 	if (copy_to_user(buf, event, cnt))
504 		result = -EFAULT;
505 
506 	kfree(event);
507 	return result;
508 }
509