xref: /linux/drivers/ptp/ptp_chardev.c (revision f8e17c17b81070f38062dce79ca7f4541851dadd)
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 		if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
140 			err = -EFAULT;
141 		break;
142 
143 	case PTP_EXTTS_REQUEST:
144 	case PTP_EXTTS_REQUEST2:
145 		memset(&req, 0, sizeof(req));
146 
147 		if (copy_from_user(&req.extts, (void __user *)arg,
148 				   sizeof(req.extts))) {
149 			err = -EFAULT;
150 			break;
151 		}
152 		if (cmd == PTP_EXTTS_REQUEST2) {
153 			/* Tell the drivers to check the flags carefully. */
154 			req.extts.flags |= PTP_STRICT_FLAGS;
155 			/* Make sure no reserved bit is set. */
156 			if ((req.extts.flags & ~PTP_EXTTS_VALID_FLAGS) ||
157 			    req.extts.rsv[0] || req.extts.rsv[1]) {
158 				err = -EINVAL;
159 				break;
160 			}
161 			/* Ensure one of the rising/falling edge bits is set. */
162 			if ((req.extts.flags & PTP_ENABLE_FEATURE) &&
163 			    (req.extts.flags & PTP_EXTTS_EDGES) == 0) {
164 				err = -EINVAL;
165 				break;
166 			}
167 		} else if (cmd == PTP_EXTTS_REQUEST) {
168 			req.extts.flags &= PTP_EXTTS_V1_VALID_FLAGS;
169 			req.extts.rsv[0] = 0;
170 			req.extts.rsv[1] = 0;
171 		}
172 		if (req.extts.index >= ops->n_ext_ts) {
173 			err = -EINVAL;
174 			break;
175 		}
176 		req.type = PTP_CLK_REQ_EXTTS;
177 		enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
178 		err = ops->enable(ops, &req, enable);
179 		break;
180 
181 	case PTP_PEROUT_REQUEST:
182 	case PTP_PEROUT_REQUEST2:
183 		memset(&req, 0, sizeof(req));
184 
185 		if (copy_from_user(&req.perout, (void __user *)arg,
186 				   sizeof(req.perout))) {
187 			err = -EFAULT;
188 			break;
189 		}
190 		if (((req.perout.flags & ~PTP_PEROUT_VALID_FLAGS) ||
191 			req.perout.rsv[0] || req.perout.rsv[1] ||
192 			req.perout.rsv[2] || req.perout.rsv[3]) &&
193 			cmd == PTP_PEROUT_REQUEST2) {
194 			err = -EINVAL;
195 			break;
196 		} else if (cmd == PTP_PEROUT_REQUEST) {
197 			req.perout.flags &= PTP_PEROUT_V1_VALID_FLAGS;
198 			req.perout.rsv[0] = 0;
199 			req.perout.rsv[1] = 0;
200 			req.perout.rsv[2] = 0;
201 			req.perout.rsv[3] = 0;
202 		}
203 		if (req.perout.index >= ops->n_per_out) {
204 			err = -EINVAL;
205 			break;
206 		}
207 		req.type = PTP_CLK_REQ_PEROUT;
208 		enable = req.perout.period.sec || req.perout.period.nsec;
209 		err = ops->enable(ops, &req, enable);
210 		break;
211 
212 	case PTP_ENABLE_PPS:
213 	case PTP_ENABLE_PPS2:
214 		memset(&req, 0, sizeof(req));
215 
216 		if (!capable(CAP_SYS_TIME))
217 			return -EPERM;
218 		req.type = PTP_CLK_REQ_PPS;
219 		enable = arg ? 1 : 0;
220 		err = ops->enable(ops, &req, enable);
221 		break;
222 
223 	case PTP_SYS_OFFSET_PRECISE:
224 	case PTP_SYS_OFFSET_PRECISE2:
225 		if (!ptp->info->getcrosststamp) {
226 			err = -EOPNOTSUPP;
227 			break;
228 		}
229 		err = ptp->info->getcrosststamp(ptp->info, &xtstamp);
230 		if (err)
231 			break;
232 
233 		memset(&precise_offset, 0, sizeof(precise_offset));
234 		ts = ktime_to_timespec64(xtstamp.device);
235 		precise_offset.device.sec = ts.tv_sec;
236 		precise_offset.device.nsec = ts.tv_nsec;
237 		ts = ktime_to_timespec64(xtstamp.sys_realtime);
238 		precise_offset.sys_realtime.sec = ts.tv_sec;
239 		precise_offset.sys_realtime.nsec = ts.tv_nsec;
240 		ts = ktime_to_timespec64(xtstamp.sys_monoraw);
241 		precise_offset.sys_monoraw.sec = ts.tv_sec;
242 		precise_offset.sys_monoraw.nsec = ts.tv_nsec;
243 		if (copy_to_user((void __user *)arg, &precise_offset,
244 				 sizeof(precise_offset)))
245 			err = -EFAULT;
246 		break;
247 
248 	case PTP_SYS_OFFSET_EXTENDED:
249 	case PTP_SYS_OFFSET_EXTENDED2:
250 		if (!ptp->info->gettimex64) {
251 			err = -EOPNOTSUPP;
252 			break;
253 		}
254 		extoff = memdup_user((void __user *)arg, sizeof(*extoff));
255 		if (IS_ERR(extoff)) {
256 			err = PTR_ERR(extoff);
257 			extoff = NULL;
258 			break;
259 		}
260 		if (extoff->n_samples > PTP_MAX_SAMPLES
261 		    || extoff->rsv[0] || extoff->rsv[1] || extoff->rsv[2]) {
262 			err = -EINVAL;
263 			break;
264 		}
265 		for (i = 0; i < extoff->n_samples; i++) {
266 			err = ptp->info->gettimex64(ptp->info, &ts, &sts);
267 			if (err)
268 				goto out;
269 			extoff->ts[i][0].sec = sts.pre_ts.tv_sec;
270 			extoff->ts[i][0].nsec = sts.pre_ts.tv_nsec;
271 			extoff->ts[i][1].sec = ts.tv_sec;
272 			extoff->ts[i][1].nsec = ts.tv_nsec;
273 			extoff->ts[i][2].sec = sts.post_ts.tv_sec;
274 			extoff->ts[i][2].nsec = sts.post_ts.tv_nsec;
275 		}
276 		if (copy_to_user((void __user *)arg, extoff, sizeof(*extoff)))
277 			err = -EFAULT;
278 		break;
279 
280 	case PTP_SYS_OFFSET:
281 	case PTP_SYS_OFFSET2:
282 		sysoff = memdup_user((void __user *)arg, sizeof(*sysoff));
283 		if (IS_ERR(sysoff)) {
284 			err = PTR_ERR(sysoff);
285 			sysoff = NULL;
286 			break;
287 		}
288 		if (sysoff->n_samples > PTP_MAX_SAMPLES) {
289 			err = -EINVAL;
290 			break;
291 		}
292 		pct = &sysoff->ts[0];
293 		for (i = 0; i < sysoff->n_samples; i++) {
294 			ktime_get_real_ts64(&ts);
295 			pct->sec = ts.tv_sec;
296 			pct->nsec = ts.tv_nsec;
297 			pct++;
298 			if (ops->gettimex64)
299 				err = ops->gettimex64(ops, &ts, NULL);
300 			else
301 				err = ops->gettime64(ops, &ts);
302 			if (err)
303 				goto out;
304 			pct->sec = ts.tv_sec;
305 			pct->nsec = ts.tv_nsec;
306 			pct++;
307 		}
308 		ktime_get_real_ts64(&ts);
309 		pct->sec = ts.tv_sec;
310 		pct->nsec = ts.tv_nsec;
311 		if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff)))
312 			err = -EFAULT;
313 		break;
314 
315 	case PTP_PIN_GETFUNC:
316 	case PTP_PIN_GETFUNC2:
317 		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
318 			err = -EFAULT;
319 			break;
320 		}
321 		if ((pd.rsv[0] || pd.rsv[1] || pd.rsv[2]
322 				|| pd.rsv[3] || pd.rsv[4])
323 			&& cmd == PTP_PIN_GETFUNC2) {
324 			err = -EINVAL;
325 			break;
326 		} else if (cmd == PTP_PIN_GETFUNC) {
327 			pd.rsv[0] = 0;
328 			pd.rsv[1] = 0;
329 			pd.rsv[2] = 0;
330 			pd.rsv[3] = 0;
331 			pd.rsv[4] = 0;
332 		}
333 		pin_index = pd.index;
334 		if (pin_index >= ops->n_pins) {
335 			err = -EINVAL;
336 			break;
337 		}
338 		pin_index = array_index_nospec(pin_index, ops->n_pins);
339 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
340 			return -ERESTARTSYS;
341 		pd = ops->pin_config[pin_index];
342 		mutex_unlock(&ptp->pincfg_mux);
343 		if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
344 			err = -EFAULT;
345 		break;
346 
347 	case PTP_PIN_SETFUNC:
348 	case PTP_PIN_SETFUNC2:
349 		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
350 			err = -EFAULT;
351 			break;
352 		}
353 		if ((pd.rsv[0] || pd.rsv[1] || pd.rsv[2]
354 				|| pd.rsv[3] || pd.rsv[4])
355 			&& cmd == PTP_PIN_SETFUNC2) {
356 			err = -EINVAL;
357 			break;
358 		} else if (cmd == PTP_PIN_SETFUNC) {
359 			pd.rsv[0] = 0;
360 			pd.rsv[1] = 0;
361 			pd.rsv[2] = 0;
362 			pd.rsv[3] = 0;
363 			pd.rsv[4] = 0;
364 		}
365 		pin_index = pd.index;
366 		if (pin_index >= ops->n_pins) {
367 			err = -EINVAL;
368 			break;
369 		}
370 		pin_index = array_index_nospec(pin_index, ops->n_pins);
371 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
372 			return -ERESTARTSYS;
373 		err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
374 		mutex_unlock(&ptp->pincfg_mux);
375 		break;
376 
377 	default:
378 		err = -ENOTTY;
379 		break;
380 	}
381 
382 out:
383 	kfree(extoff);
384 	kfree(sysoff);
385 	return err;
386 }
387 
388 __poll_t ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
389 {
390 	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
391 
392 	poll_wait(fp, &ptp->tsev_wq, wait);
393 
394 	return queue_cnt(&ptp->tsevq) ? EPOLLIN : 0;
395 }
396 
397 #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
398 
399 ssize_t ptp_read(struct posix_clock *pc,
400 		 uint rdflags, char __user *buf, size_t cnt)
401 {
402 	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
403 	struct timestamp_event_queue *queue = &ptp->tsevq;
404 	struct ptp_extts_event *event;
405 	unsigned long flags;
406 	size_t qcnt, i;
407 	int result;
408 
409 	if (cnt % sizeof(struct ptp_extts_event) != 0)
410 		return -EINVAL;
411 
412 	if (cnt > EXTTS_BUFSIZE)
413 		cnt = EXTTS_BUFSIZE;
414 
415 	cnt = cnt / sizeof(struct ptp_extts_event);
416 
417 	if (mutex_lock_interruptible(&ptp->tsevq_mux))
418 		return -ERESTARTSYS;
419 
420 	if (wait_event_interruptible(ptp->tsev_wq,
421 				     ptp->defunct || queue_cnt(queue))) {
422 		mutex_unlock(&ptp->tsevq_mux);
423 		return -ERESTARTSYS;
424 	}
425 
426 	if (ptp->defunct) {
427 		mutex_unlock(&ptp->tsevq_mux);
428 		return -ENODEV;
429 	}
430 
431 	event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
432 	if (!event) {
433 		mutex_unlock(&ptp->tsevq_mux);
434 		return -ENOMEM;
435 	}
436 
437 	spin_lock_irqsave(&queue->lock, flags);
438 
439 	qcnt = queue_cnt(queue);
440 
441 	if (cnt > qcnt)
442 		cnt = qcnt;
443 
444 	for (i = 0; i < cnt; i++) {
445 		event[i] = queue->buf[queue->head];
446 		queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
447 	}
448 
449 	spin_unlock_irqrestore(&queue->lock, flags);
450 
451 	cnt = cnt * sizeof(struct ptp_extts_event);
452 
453 	mutex_unlock(&ptp->tsevq_mux);
454 
455 	result = cnt;
456 	if (copy_to_user(buf, event, cnt))
457 		result = -EFAULT;
458 
459 	kfree(event);
460 	return result;
461 }
462