xref: /openbmc/linux/drivers/ptp/ptp_chardev.c (revision 842ed298)
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 		if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
141 			err = -EFAULT;
142 		break;
143 
144 	case PTP_EXTTS_REQUEST:
145 	case PTP_EXTTS_REQUEST2:
146 		memset(&req, 0, sizeof(req));
147 
148 		if (copy_from_user(&req.extts, (void __user *)arg,
149 				   sizeof(req.extts))) {
150 			err = -EFAULT;
151 			break;
152 		}
153 		if (cmd == PTP_EXTTS_REQUEST2) {
154 			/* Tell the drivers to check the flags carefully. */
155 			req.extts.flags |= PTP_STRICT_FLAGS;
156 			/* Make sure no reserved bit is set. */
157 			if ((req.extts.flags & ~PTP_EXTTS_VALID_FLAGS) ||
158 			    req.extts.rsv[0] || req.extts.rsv[1]) {
159 				err = -EINVAL;
160 				break;
161 			}
162 			/* Ensure one of the rising/falling edge bits is set. */
163 			if ((req.extts.flags & PTP_ENABLE_FEATURE) &&
164 			    (req.extts.flags & PTP_EXTTS_EDGES) == 0) {
165 				err = -EINVAL;
166 				break;
167 			}
168 		} else if (cmd == PTP_EXTTS_REQUEST) {
169 			req.extts.flags &= PTP_EXTTS_V1_VALID_FLAGS;
170 			req.extts.rsv[0] = 0;
171 			req.extts.rsv[1] = 0;
172 		}
173 		if (req.extts.index >= ops->n_ext_ts) {
174 			err = -EINVAL;
175 			break;
176 		}
177 		req.type = PTP_CLK_REQ_EXTTS;
178 		enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
179 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
180 			return -ERESTARTSYS;
181 		err = ops->enable(ops, &req, enable);
182 		mutex_unlock(&ptp->pincfg_mux);
183 		break;
184 
185 	case PTP_PEROUT_REQUEST:
186 	case PTP_PEROUT_REQUEST2:
187 		memset(&req, 0, sizeof(req));
188 
189 		if (copy_from_user(&req.perout, (void __user *)arg,
190 				   sizeof(req.perout))) {
191 			err = -EFAULT;
192 			break;
193 		}
194 		if (cmd == PTP_PEROUT_REQUEST2) {
195 			struct ptp_perout_request *perout = &req.perout;
196 
197 			if (perout->flags & ~PTP_PEROUT_VALID_FLAGS) {
198 				err = -EINVAL;
199 				break;
200 			}
201 			/*
202 			 * The "on" field has undefined meaning if
203 			 * PTP_PEROUT_DUTY_CYCLE isn't set, we must still treat
204 			 * it as reserved, which must be set to zero.
205 			 */
206 			if (!(perout->flags & PTP_PEROUT_DUTY_CYCLE) &&
207 			    (perout->rsv[0] || perout->rsv[1] ||
208 			     perout->rsv[2] || perout->rsv[3])) {
209 				err = -EINVAL;
210 				break;
211 			}
212 			if (perout->flags & PTP_PEROUT_DUTY_CYCLE) {
213 				/* The duty cycle must be subunitary. */
214 				if (perout->on.sec > perout->period.sec ||
215 				    (perout->on.sec == perout->period.sec &&
216 				     perout->on.nsec > perout->period.nsec)) {
217 					err = -ERANGE;
218 					break;
219 				}
220 			}
221 			if (perout->flags & PTP_PEROUT_PHASE) {
222 				/*
223 				 * The phase should be specified modulo the
224 				 * period, therefore anything equal or larger
225 				 * than 1 period is invalid.
226 				 */
227 				if (perout->phase.sec > perout->period.sec ||
228 				    (perout->phase.sec == perout->period.sec &&
229 				     perout->phase.nsec >= perout->period.nsec)) {
230 					err = -ERANGE;
231 					break;
232 				}
233 			}
234 		} else if (cmd == PTP_PEROUT_REQUEST) {
235 			req.perout.flags &= PTP_PEROUT_V1_VALID_FLAGS;
236 			req.perout.rsv[0] = 0;
237 			req.perout.rsv[1] = 0;
238 			req.perout.rsv[2] = 0;
239 			req.perout.rsv[3] = 0;
240 		}
241 		if (req.perout.index >= ops->n_per_out) {
242 			err = -EINVAL;
243 			break;
244 		}
245 		req.type = PTP_CLK_REQ_PEROUT;
246 		enable = req.perout.period.sec || req.perout.period.nsec;
247 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
248 			return -ERESTARTSYS;
249 		err = ops->enable(ops, &req, enable);
250 		mutex_unlock(&ptp->pincfg_mux);
251 		break;
252 
253 	case PTP_ENABLE_PPS:
254 	case PTP_ENABLE_PPS2:
255 		memset(&req, 0, sizeof(req));
256 
257 		if (!capable(CAP_SYS_TIME))
258 			return -EPERM;
259 		req.type = PTP_CLK_REQ_PPS;
260 		enable = arg ? 1 : 0;
261 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
262 			return -ERESTARTSYS;
263 		err = ops->enable(ops, &req, enable);
264 		mutex_unlock(&ptp->pincfg_mux);
265 		break;
266 
267 	case PTP_SYS_OFFSET_PRECISE:
268 	case PTP_SYS_OFFSET_PRECISE2:
269 		if (!ptp->info->getcrosststamp) {
270 			err = -EOPNOTSUPP;
271 			break;
272 		}
273 		err = ptp->info->getcrosststamp(ptp->info, &xtstamp);
274 		if (err)
275 			break;
276 
277 		memset(&precise_offset, 0, sizeof(precise_offset));
278 		ts = ktime_to_timespec64(xtstamp.device);
279 		precise_offset.device.sec = ts.tv_sec;
280 		precise_offset.device.nsec = ts.tv_nsec;
281 		ts = ktime_to_timespec64(xtstamp.sys_realtime);
282 		precise_offset.sys_realtime.sec = ts.tv_sec;
283 		precise_offset.sys_realtime.nsec = ts.tv_nsec;
284 		ts = ktime_to_timespec64(xtstamp.sys_monoraw);
285 		precise_offset.sys_monoraw.sec = ts.tv_sec;
286 		precise_offset.sys_monoraw.nsec = ts.tv_nsec;
287 		if (copy_to_user((void __user *)arg, &precise_offset,
288 				 sizeof(precise_offset)))
289 			err = -EFAULT;
290 		break;
291 
292 	case PTP_SYS_OFFSET_EXTENDED:
293 	case PTP_SYS_OFFSET_EXTENDED2:
294 		if (!ptp->info->gettimex64) {
295 			err = -EOPNOTSUPP;
296 			break;
297 		}
298 		extoff = memdup_user((void __user *)arg, sizeof(*extoff));
299 		if (IS_ERR(extoff)) {
300 			err = PTR_ERR(extoff);
301 			extoff = NULL;
302 			break;
303 		}
304 		if (extoff->n_samples > PTP_MAX_SAMPLES
305 		    || extoff->rsv[0] || extoff->rsv[1] || extoff->rsv[2]) {
306 			err = -EINVAL;
307 			break;
308 		}
309 		for (i = 0; i < extoff->n_samples; i++) {
310 			err = ptp->info->gettimex64(ptp->info, &ts, &sts);
311 			if (err)
312 				goto out;
313 			extoff->ts[i][0].sec = sts.pre_ts.tv_sec;
314 			extoff->ts[i][0].nsec = sts.pre_ts.tv_nsec;
315 			extoff->ts[i][1].sec = ts.tv_sec;
316 			extoff->ts[i][1].nsec = ts.tv_nsec;
317 			extoff->ts[i][2].sec = sts.post_ts.tv_sec;
318 			extoff->ts[i][2].nsec = sts.post_ts.tv_nsec;
319 		}
320 		if (copy_to_user((void __user *)arg, extoff, sizeof(*extoff)))
321 			err = -EFAULT;
322 		break;
323 
324 	case PTP_SYS_OFFSET:
325 	case PTP_SYS_OFFSET2:
326 		sysoff = memdup_user((void __user *)arg, sizeof(*sysoff));
327 		if (IS_ERR(sysoff)) {
328 			err = PTR_ERR(sysoff);
329 			sysoff = NULL;
330 			break;
331 		}
332 		if (sysoff->n_samples > PTP_MAX_SAMPLES) {
333 			err = -EINVAL;
334 			break;
335 		}
336 		pct = &sysoff->ts[0];
337 		for (i = 0; i < sysoff->n_samples; i++) {
338 			ktime_get_real_ts64(&ts);
339 			pct->sec = ts.tv_sec;
340 			pct->nsec = ts.tv_nsec;
341 			pct++;
342 			if (ops->gettimex64)
343 				err = ops->gettimex64(ops, &ts, NULL);
344 			else
345 				err = ops->gettime64(ops, &ts);
346 			if (err)
347 				goto out;
348 			pct->sec = ts.tv_sec;
349 			pct->nsec = ts.tv_nsec;
350 			pct++;
351 		}
352 		ktime_get_real_ts64(&ts);
353 		pct->sec = ts.tv_sec;
354 		pct->nsec = ts.tv_nsec;
355 		if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff)))
356 			err = -EFAULT;
357 		break;
358 
359 	case PTP_PIN_GETFUNC:
360 	case PTP_PIN_GETFUNC2:
361 		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
362 			err = -EFAULT;
363 			break;
364 		}
365 		if ((pd.rsv[0] || pd.rsv[1] || pd.rsv[2]
366 				|| pd.rsv[3] || pd.rsv[4])
367 			&& cmd == PTP_PIN_GETFUNC2) {
368 			err = -EINVAL;
369 			break;
370 		} else if (cmd == PTP_PIN_GETFUNC) {
371 			pd.rsv[0] = 0;
372 			pd.rsv[1] = 0;
373 			pd.rsv[2] = 0;
374 			pd.rsv[3] = 0;
375 			pd.rsv[4] = 0;
376 		}
377 		pin_index = pd.index;
378 		if (pin_index >= ops->n_pins) {
379 			err = -EINVAL;
380 			break;
381 		}
382 		pin_index = array_index_nospec(pin_index, ops->n_pins);
383 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
384 			return -ERESTARTSYS;
385 		pd = ops->pin_config[pin_index];
386 		mutex_unlock(&ptp->pincfg_mux);
387 		if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
388 			err = -EFAULT;
389 		break;
390 
391 	case PTP_PIN_SETFUNC:
392 	case PTP_PIN_SETFUNC2:
393 		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
394 			err = -EFAULT;
395 			break;
396 		}
397 		if ((pd.rsv[0] || pd.rsv[1] || pd.rsv[2]
398 				|| pd.rsv[3] || pd.rsv[4])
399 			&& cmd == PTP_PIN_SETFUNC2) {
400 			err = -EINVAL;
401 			break;
402 		} else if (cmd == PTP_PIN_SETFUNC) {
403 			pd.rsv[0] = 0;
404 			pd.rsv[1] = 0;
405 			pd.rsv[2] = 0;
406 			pd.rsv[3] = 0;
407 			pd.rsv[4] = 0;
408 		}
409 		pin_index = pd.index;
410 		if (pin_index >= ops->n_pins) {
411 			err = -EINVAL;
412 			break;
413 		}
414 		pin_index = array_index_nospec(pin_index, ops->n_pins);
415 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
416 			return -ERESTARTSYS;
417 		err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
418 		mutex_unlock(&ptp->pincfg_mux);
419 		break;
420 
421 	default:
422 		err = -ENOTTY;
423 		break;
424 	}
425 
426 out:
427 	kfree(extoff);
428 	kfree(sysoff);
429 	return err;
430 }
431 
432 __poll_t ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
433 {
434 	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
435 
436 	poll_wait(fp, &ptp->tsev_wq, wait);
437 
438 	return queue_cnt(&ptp->tsevq) ? EPOLLIN : 0;
439 }
440 
441 #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
442 
443 ssize_t ptp_read(struct posix_clock *pc,
444 		 uint rdflags, char __user *buf, size_t cnt)
445 {
446 	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
447 	struct timestamp_event_queue *queue = &ptp->tsevq;
448 	struct ptp_extts_event *event;
449 	unsigned long flags;
450 	size_t qcnt, i;
451 	int result;
452 
453 	if (cnt % sizeof(struct ptp_extts_event) != 0)
454 		return -EINVAL;
455 
456 	if (cnt > EXTTS_BUFSIZE)
457 		cnt = EXTTS_BUFSIZE;
458 
459 	cnt = cnt / sizeof(struct ptp_extts_event);
460 
461 	if (mutex_lock_interruptible(&ptp->tsevq_mux))
462 		return -ERESTARTSYS;
463 
464 	if (wait_event_interruptible(ptp->tsev_wq,
465 				     ptp->defunct || queue_cnt(queue))) {
466 		mutex_unlock(&ptp->tsevq_mux);
467 		return -ERESTARTSYS;
468 	}
469 
470 	if (ptp->defunct) {
471 		mutex_unlock(&ptp->tsevq_mux);
472 		return -ENODEV;
473 	}
474 
475 	event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
476 	if (!event) {
477 		mutex_unlock(&ptp->tsevq_mux);
478 		return -ENOMEM;
479 	}
480 
481 	spin_lock_irqsave(&queue->lock, flags);
482 
483 	qcnt = queue_cnt(queue);
484 
485 	if (cnt > qcnt)
486 		cnt = qcnt;
487 
488 	for (i = 0; i < cnt; i++) {
489 		event[i] = queue->buf[queue->head];
490 		queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
491 	}
492 
493 	spin_unlock_irqrestore(&queue->lock, flags);
494 
495 	cnt = cnt * sizeof(struct ptp_extts_event);
496 
497 	mutex_unlock(&ptp->tsevq_mux);
498 
499 	result = cnt;
500 	if (copy_to_user(buf, event, cnt))
501 		result = -EFAULT;
502 
503 	kfree(event);
504 	return result;
505 }
506