xref: /linux/drivers/ptp/ptp_chardev.c (revision 8795a739e5c72abeec51caf36b6df2b37e5720c5)
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 (((req.extts.flags & ~PTP_EXTTS_VALID_FLAGS) ||
153 			req.extts.rsv[0] || req.extts.rsv[1]) &&
154 			cmd == PTP_EXTTS_REQUEST2) {
155 			err = -EINVAL;
156 			break;
157 		} else if (cmd == PTP_EXTTS_REQUEST) {
158 			req.extts.flags &= PTP_EXTTS_V1_VALID_FLAGS;
159 			req.extts.rsv[0] = 0;
160 			req.extts.rsv[1] = 0;
161 		}
162 		if (req.extts.index >= ops->n_ext_ts) {
163 			err = -EINVAL;
164 			break;
165 		}
166 		req.type = PTP_CLK_REQ_EXTTS;
167 		enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
168 		err = ops->enable(ops, &req, enable);
169 		break;
170 
171 	case PTP_PEROUT_REQUEST:
172 	case PTP_PEROUT_REQUEST2:
173 		memset(&req, 0, sizeof(req));
174 
175 		if (copy_from_user(&req.perout, (void __user *)arg,
176 				   sizeof(req.perout))) {
177 			err = -EFAULT;
178 			break;
179 		}
180 		if (((req.perout.flags & ~PTP_PEROUT_VALID_FLAGS) ||
181 			req.perout.rsv[0] || req.perout.rsv[1] ||
182 			req.perout.rsv[2] || req.perout.rsv[3]) &&
183 			cmd == PTP_PEROUT_REQUEST2) {
184 			err = -EINVAL;
185 			break;
186 		} else if (cmd == PTP_PEROUT_REQUEST) {
187 			req.perout.flags &= PTP_PEROUT_V1_VALID_FLAGS;
188 			req.perout.rsv[0] = 0;
189 			req.perout.rsv[1] = 0;
190 			req.perout.rsv[2] = 0;
191 			req.perout.rsv[3] = 0;
192 		}
193 		if (req.perout.index >= ops->n_per_out) {
194 			err = -EINVAL;
195 			break;
196 		}
197 		req.type = PTP_CLK_REQ_PEROUT;
198 		enable = req.perout.period.sec || req.perout.period.nsec;
199 		err = ops->enable(ops, &req, enable);
200 		break;
201 
202 	case PTP_ENABLE_PPS:
203 	case PTP_ENABLE_PPS2:
204 		memset(&req, 0, sizeof(req));
205 
206 		if (!capable(CAP_SYS_TIME))
207 			return -EPERM;
208 		req.type = PTP_CLK_REQ_PPS;
209 		enable = arg ? 1 : 0;
210 		err = ops->enable(ops, &req, enable);
211 		break;
212 
213 	case PTP_SYS_OFFSET_PRECISE:
214 	case PTP_SYS_OFFSET_PRECISE2:
215 		if (!ptp->info->getcrosststamp) {
216 			err = -EOPNOTSUPP;
217 			break;
218 		}
219 		err = ptp->info->getcrosststamp(ptp->info, &xtstamp);
220 		if (err)
221 			break;
222 
223 		memset(&precise_offset, 0, sizeof(precise_offset));
224 		ts = ktime_to_timespec64(xtstamp.device);
225 		precise_offset.device.sec = ts.tv_sec;
226 		precise_offset.device.nsec = ts.tv_nsec;
227 		ts = ktime_to_timespec64(xtstamp.sys_realtime);
228 		precise_offset.sys_realtime.sec = ts.tv_sec;
229 		precise_offset.sys_realtime.nsec = ts.tv_nsec;
230 		ts = ktime_to_timespec64(xtstamp.sys_monoraw);
231 		precise_offset.sys_monoraw.sec = ts.tv_sec;
232 		precise_offset.sys_monoraw.nsec = ts.tv_nsec;
233 		if (copy_to_user((void __user *)arg, &precise_offset,
234 				 sizeof(precise_offset)))
235 			err = -EFAULT;
236 		break;
237 
238 	case PTP_SYS_OFFSET_EXTENDED:
239 	case PTP_SYS_OFFSET_EXTENDED2:
240 		if (!ptp->info->gettimex64) {
241 			err = -EOPNOTSUPP;
242 			break;
243 		}
244 		extoff = memdup_user((void __user *)arg, sizeof(*extoff));
245 		if (IS_ERR(extoff)) {
246 			err = PTR_ERR(extoff);
247 			extoff = NULL;
248 			break;
249 		}
250 		if (extoff->n_samples > PTP_MAX_SAMPLES
251 		    || extoff->rsv[0] || extoff->rsv[1] || extoff->rsv[2]) {
252 			err = -EINVAL;
253 			break;
254 		}
255 		for (i = 0; i < extoff->n_samples; i++) {
256 			err = ptp->info->gettimex64(ptp->info, &ts, &sts);
257 			if (err)
258 				goto out;
259 			extoff->ts[i][0].sec = sts.pre_ts.tv_sec;
260 			extoff->ts[i][0].nsec = sts.pre_ts.tv_nsec;
261 			extoff->ts[i][1].sec = ts.tv_sec;
262 			extoff->ts[i][1].nsec = ts.tv_nsec;
263 			extoff->ts[i][2].sec = sts.post_ts.tv_sec;
264 			extoff->ts[i][2].nsec = sts.post_ts.tv_nsec;
265 		}
266 		if (copy_to_user((void __user *)arg, extoff, sizeof(*extoff)))
267 			err = -EFAULT;
268 		break;
269 
270 	case PTP_SYS_OFFSET:
271 	case PTP_SYS_OFFSET2:
272 		sysoff = memdup_user((void __user *)arg, sizeof(*sysoff));
273 		if (IS_ERR(sysoff)) {
274 			err = PTR_ERR(sysoff);
275 			sysoff = NULL;
276 			break;
277 		}
278 		if (sysoff->n_samples > PTP_MAX_SAMPLES) {
279 			err = -EINVAL;
280 			break;
281 		}
282 		pct = &sysoff->ts[0];
283 		for (i = 0; i < sysoff->n_samples; i++) {
284 			ktime_get_real_ts64(&ts);
285 			pct->sec = ts.tv_sec;
286 			pct->nsec = ts.tv_nsec;
287 			pct++;
288 			if (ops->gettimex64)
289 				err = ops->gettimex64(ops, &ts, NULL);
290 			else
291 				err = ops->gettime64(ops, &ts);
292 			if (err)
293 				goto out;
294 			pct->sec = ts.tv_sec;
295 			pct->nsec = ts.tv_nsec;
296 			pct++;
297 		}
298 		ktime_get_real_ts64(&ts);
299 		pct->sec = ts.tv_sec;
300 		pct->nsec = ts.tv_nsec;
301 		if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff)))
302 			err = -EFAULT;
303 		break;
304 
305 	case PTP_PIN_GETFUNC:
306 	case PTP_PIN_GETFUNC2:
307 		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
308 			err = -EFAULT;
309 			break;
310 		}
311 		if ((pd.rsv[0] || pd.rsv[1] || pd.rsv[2]
312 				|| pd.rsv[3] || pd.rsv[4])
313 			&& cmd == PTP_PIN_GETFUNC2) {
314 			err = -EINVAL;
315 			break;
316 		} else if (cmd == PTP_PIN_GETFUNC) {
317 			pd.rsv[0] = 0;
318 			pd.rsv[1] = 0;
319 			pd.rsv[2] = 0;
320 			pd.rsv[3] = 0;
321 			pd.rsv[4] = 0;
322 		}
323 		pin_index = pd.index;
324 		if (pin_index >= ops->n_pins) {
325 			err = -EINVAL;
326 			break;
327 		}
328 		pin_index = array_index_nospec(pin_index, ops->n_pins);
329 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
330 			return -ERESTARTSYS;
331 		pd = ops->pin_config[pin_index];
332 		mutex_unlock(&ptp->pincfg_mux);
333 		if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
334 			err = -EFAULT;
335 		break;
336 
337 	case PTP_PIN_SETFUNC:
338 	case PTP_PIN_SETFUNC2:
339 		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
340 			err = -EFAULT;
341 			break;
342 		}
343 		if ((pd.rsv[0] || pd.rsv[1] || pd.rsv[2]
344 				|| pd.rsv[3] || pd.rsv[4])
345 			&& cmd == PTP_PIN_SETFUNC2) {
346 			err = -EINVAL;
347 			break;
348 		} else if (cmd == PTP_PIN_SETFUNC) {
349 			pd.rsv[0] = 0;
350 			pd.rsv[1] = 0;
351 			pd.rsv[2] = 0;
352 			pd.rsv[3] = 0;
353 			pd.rsv[4] = 0;
354 		}
355 		pin_index = pd.index;
356 		if (pin_index >= ops->n_pins) {
357 			err = -EINVAL;
358 			break;
359 		}
360 		pin_index = array_index_nospec(pin_index, ops->n_pins);
361 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
362 			return -ERESTARTSYS;
363 		err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
364 		mutex_unlock(&ptp->pincfg_mux);
365 		break;
366 
367 	default:
368 		err = -ENOTTY;
369 		break;
370 	}
371 
372 out:
373 	kfree(extoff);
374 	kfree(sysoff);
375 	return err;
376 }
377 
378 __poll_t ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
379 {
380 	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
381 
382 	poll_wait(fp, &ptp->tsev_wq, wait);
383 
384 	return queue_cnt(&ptp->tsevq) ? EPOLLIN : 0;
385 }
386 
387 #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
388 
389 ssize_t ptp_read(struct posix_clock *pc,
390 		 uint rdflags, char __user *buf, size_t cnt)
391 {
392 	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
393 	struct timestamp_event_queue *queue = &ptp->tsevq;
394 	struct ptp_extts_event *event;
395 	unsigned long flags;
396 	size_t qcnt, i;
397 	int result;
398 
399 	if (cnt % sizeof(struct ptp_extts_event) != 0)
400 		return -EINVAL;
401 
402 	if (cnt > EXTTS_BUFSIZE)
403 		cnt = EXTTS_BUFSIZE;
404 
405 	cnt = cnt / sizeof(struct ptp_extts_event);
406 
407 	if (mutex_lock_interruptible(&ptp->tsevq_mux))
408 		return -ERESTARTSYS;
409 
410 	if (wait_event_interruptible(ptp->tsev_wq,
411 				     ptp->defunct || queue_cnt(queue))) {
412 		mutex_unlock(&ptp->tsevq_mux);
413 		return -ERESTARTSYS;
414 	}
415 
416 	if (ptp->defunct) {
417 		mutex_unlock(&ptp->tsevq_mux);
418 		return -ENODEV;
419 	}
420 
421 	event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
422 	if (!event) {
423 		mutex_unlock(&ptp->tsevq_mux);
424 		return -ENOMEM;
425 	}
426 
427 	spin_lock_irqsave(&queue->lock, flags);
428 
429 	qcnt = queue_cnt(queue);
430 
431 	if (cnt > qcnt)
432 		cnt = qcnt;
433 
434 	for (i = 0; i < cnt; i++) {
435 		event[i] = queue->buf[queue->head];
436 		queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
437 	}
438 
439 	spin_unlock_irqrestore(&queue->lock, flags);
440 
441 	cnt = cnt * sizeof(struct ptp_extts_event);
442 
443 	mutex_unlock(&ptp->tsevq_mux);
444 
445 	result = cnt;
446 	if (copy_to_user(buf, event, cnt))
447 		result = -EFAULT;
448 
449 	kfree(event);
450 	return result;
451 }
452