xref: /openbmc/linux/drivers/ptp/ptp_chardev.c (revision b03afaa8)
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 		} else if (cmd == PTP_PEROUT_REQUEST) {
222 			req.perout.flags &= PTP_PEROUT_V1_VALID_FLAGS;
223 			req.perout.rsv[0] = 0;
224 			req.perout.rsv[1] = 0;
225 			req.perout.rsv[2] = 0;
226 			req.perout.rsv[3] = 0;
227 		}
228 		if (req.perout.index >= ops->n_per_out) {
229 			err = -EINVAL;
230 			break;
231 		}
232 		req.type = PTP_CLK_REQ_PEROUT;
233 		enable = req.perout.period.sec || req.perout.period.nsec;
234 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
235 			return -ERESTARTSYS;
236 		err = ops->enable(ops, &req, enable);
237 		mutex_unlock(&ptp->pincfg_mux);
238 		break;
239 
240 	case PTP_ENABLE_PPS:
241 	case PTP_ENABLE_PPS2:
242 		memset(&req, 0, sizeof(req));
243 
244 		if (!capable(CAP_SYS_TIME))
245 			return -EPERM;
246 		req.type = PTP_CLK_REQ_PPS;
247 		enable = arg ? 1 : 0;
248 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
249 			return -ERESTARTSYS;
250 		err = ops->enable(ops, &req, enable);
251 		mutex_unlock(&ptp->pincfg_mux);
252 		break;
253 
254 	case PTP_SYS_OFFSET_PRECISE:
255 	case PTP_SYS_OFFSET_PRECISE2:
256 		if (!ptp->info->getcrosststamp) {
257 			err = -EOPNOTSUPP;
258 			break;
259 		}
260 		err = ptp->info->getcrosststamp(ptp->info, &xtstamp);
261 		if (err)
262 			break;
263 
264 		memset(&precise_offset, 0, sizeof(precise_offset));
265 		ts = ktime_to_timespec64(xtstamp.device);
266 		precise_offset.device.sec = ts.tv_sec;
267 		precise_offset.device.nsec = ts.tv_nsec;
268 		ts = ktime_to_timespec64(xtstamp.sys_realtime);
269 		precise_offset.sys_realtime.sec = ts.tv_sec;
270 		precise_offset.sys_realtime.nsec = ts.tv_nsec;
271 		ts = ktime_to_timespec64(xtstamp.sys_monoraw);
272 		precise_offset.sys_monoraw.sec = ts.tv_sec;
273 		precise_offset.sys_monoraw.nsec = ts.tv_nsec;
274 		if (copy_to_user((void __user *)arg, &precise_offset,
275 				 sizeof(precise_offset)))
276 			err = -EFAULT;
277 		break;
278 
279 	case PTP_SYS_OFFSET_EXTENDED:
280 	case PTP_SYS_OFFSET_EXTENDED2:
281 		if (!ptp->info->gettimex64) {
282 			err = -EOPNOTSUPP;
283 			break;
284 		}
285 		extoff = memdup_user((void __user *)arg, sizeof(*extoff));
286 		if (IS_ERR(extoff)) {
287 			err = PTR_ERR(extoff);
288 			extoff = NULL;
289 			break;
290 		}
291 		if (extoff->n_samples > PTP_MAX_SAMPLES
292 		    || extoff->rsv[0] || extoff->rsv[1] || extoff->rsv[2]) {
293 			err = -EINVAL;
294 			break;
295 		}
296 		for (i = 0; i < extoff->n_samples; i++) {
297 			err = ptp->info->gettimex64(ptp->info, &ts, &sts);
298 			if (err)
299 				goto out;
300 			extoff->ts[i][0].sec = sts.pre_ts.tv_sec;
301 			extoff->ts[i][0].nsec = sts.pre_ts.tv_nsec;
302 			extoff->ts[i][1].sec = ts.tv_sec;
303 			extoff->ts[i][1].nsec = ts.tv_nsec;
304 			extoff->ts[i][2].sec = sts.post_ts.tv_sec;
305 			extoff->ts[i][2].nsec = sts.post_ts.tv_nsec;
306 		}
307 		if (copy_to_user((void __user *)arg, extoff, sizeof(*extoff)))
308 			err = -EFAULT;
309 		break;
310 
311 	case PTP_SYS_OFFSET:
312 	case PTP_SYS_OFFSET2:
313 		sysoff = memdup_user((void __user *)arg, sizeof(*sysoff));
314 		if (IS_ERR(sysoff)) {
315 			err = PTR_ERR(sysoff);
316 			sysoff = NULL;
317 			break;
318 		}
319 		if (sysoff->n_samples > PTP_MAX_SAMPLES) {
320 			err = -EINVAL;
321 			break;
322 		}
323 		pct = &sysoff->ts[0];
324 		for (i = 0; i < sysoff->n_samples; i++) {
325 			ktime_get_real_ts64(&ts);
326 			pct->sec = ts.tv_sec;
327 			pct->nsec = ts.tv_nsec;
328 			pct++;
329 			if (ops->gettimex64)
330 				err = ops->gettimex64(ops, &ts, NULL);
331 			else
332 				err = ops->gettime64(ops, &ts);
333 			if (err)
334 				goto out;
335 			pct->sec = ts.tv_sec;
336 			pct->nsec = ts.tv_nsec;
337 			pct++;
338 		}
339 		ktime_get_real_ts64(&ts);
340 		pct->sec = ts.tv_sec;
341 		pct->nsec = ts.tv_nsec;
342 		if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff)))
343 			err = -EFAULT;
344 		break;
345 
346 	case PTP_PIN_GETFUNC:
347 	case PTP_PIN_GETFUNC2:
348 		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
349 			err = -EFAULT;
350 			break;
351 		}
352 		if ((pd.rsv[0] || pd.rsv[1] || pd.rsv[2]
353 				|| pd.rsv[3] || pd.rsv[4])
354 			&& cmd == PTP_PIN_GETFUNC2) {
355 			err = -EINVAL;
356 			break;
357 		} else if (cmd == PTP_PIN_GETFUNC) {
358 			pd.rsv[0] = 0;
359 			pd.rsv[1] = 0;
360 			pd.rsv[2] = 0;
361 			pd.rsv[3] = 0;
362 			pd.rsv[4] = 0;
363 		}
364 		pin_index = pd.index;
365 		if (pin_index >= ops->n_pins) {
366 			err = -EINVAL;
367 			break;
368 		}
369 		pin_index = array_index_nospec(pin_index, ops->n_pins);
370 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
371 			return -ERESTARTSYS;
372 		pd = ops->pin_config[pin_index];
373 		mutex_unlock(&ptp->pincfg_mux);
374 		if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
375 			err = -EFAULT;
376 		break;
377 
378 	case PTP_PIN_SETFUNC:
379 	case PTP_PIN_SETFUNC2:
380 		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
381 			err = -EFAULT;
382 			break;
383 		}
384 		if ((pd.rsv[0] || pd.rsv[1] || pd.rsv[2]
385 				|| pd.rsv[3] || pd.rsv[4])
386 			&& cmd == PTP_PIN_SETFUNC2) {
387 			err = -EINVAL;
388 			break;
389 		} else if (cmd == PTP_PIN_SETFUNC) {
390 			pd.rsv[0] = 0;
391 			pd.rsv[1] = 0;
392 			pd.rsv[2] = 0;
393 			pd.rsv[3] = 0;
394 			pd.rsv[4] = 0;
395 		}
396 		pin_index = pd.index;
397 		if (pin_index >= ops->n_pins) {
398 			err = -EINVAL;
399 			break;
400 		}
401 		pin_index = array_index_nospec(pin_index, ops->n_pins);
402 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
403 			return -ERESTARTSYS;
404 		err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
405 		mutex_unlock(&ptp->pincfg_mux);
406 		break;
407 
408 	default:
409 		err = -ENOTTY;
410 		break;
411 	}
412 
413 out:
414 	kfree(extoff);
415 	kfree(sysoff);
416 	return err;
417 }
418 
419 __poll_t ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
420 {
421 	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
422 
423 	poll_wait(fp, &ptp->tsev_wq, wait);
424 
425 	return queue_cnt(&ptp->tsevq) ? EPOLLIN : 0;
426 }
427 
428 #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
429 
430 ssize_t ptp_read(struct posix_clock *pc,
431 		 uint rdflags, char __user *buf, size_t cnt)
432 {
433 	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
434 	struct timestamp_event_queue *queue = &ptp->tsevq;
435 	struct ptp_extts_event *event;
436 	unsigned long flags;
437 	size_t qcnt, i;
438 	int result;
439 
440 	if (cnt % sizeof(struct ptp_extts_event) != 0)
441 		return -EINVAL;
442 
443 	if (cnt > EXTTS_BUFSIZE)
444 		cnt = EXTTS_BUFSIZE;
445 
446 	cnt = cnt / sizeof(struct ptp_extts_event);
447 
448 	if (mutex_lock_interruptible(&ptp->tsevq_mux))
449 		return -ERESTARTSYS;
450 
451 	if (wait_event_interruptible(ptp->tsev_wq,
452 				     ptp->defunct || queue_cnt(queue))) {
453 		mutex_unlock(&ptp->tsevq_mux);
454 		return -ERESTARTSYS;
455 	}
456 
457 	if (ptp->defunct) {
458 		mutex_unlock(&ptp->tsevq_mux);
459 		return -ENODEV;
460 	}
461 
462 	event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
463 	if (!event) {
464 		mutex_unlock(&ptp->tsevq_mux);
465 		return -ENOMEM;
466 	}
467 
468 	spin_lock_irqsave(&queue->lock, flags);
469 
470 	qcnt = queue_cnt(queue);
471 
472 	if (cnt > qcnt)
473 		cnt = qcnt;
474 
475 	for (i = 0; i < cnt; i++) {
476 		event[i] = queue->buf[queue->head];
477 		queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
478 	}
479 
480 	spin_unlock_irqrestore(&queue->lock, flags);
481 
482 	cnt = cnt * sizeof(struct ptp_extts_event);
483 
484 	mutex_unlock(&ptp->tsevq_mux);
485 
486 	result = cnt;
487 	if (copy_to_user(buf, event, cnt))
488 		result = -EFAULT;
489 
490 	kfree(event);
491 	return result;
492 }
493