xref: /openbmc/linux/drivers/ptp/ptp_chardev.c (revision 82df5b73)
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 (((req.perout.flags & ~PTP_PEROUT_VALID_FLAGS) ||
195 			req.perout.rsv[0] || req.perout.rsv[1] ||
196 			req.perout.rsv[2] || req.perout.rsv[3]) &&
197 			cmd == PTP_PEROUT_REQUEST2) {
198 			err = -EINVAL;
199 			break;
200 		} else if (cmd == PTP_PEROUT_REQUEST) {
201 			req.perout.flags &= PTP_PEROUT_V1_VALID_FLAGS;
202 			req.perout.rsv[0] = 0;
203 			req.perout.rsv[1] = 0;
204 			req.perout.rsv[2] = 0;
205 			req.perout.rsv[3] = 0;
206 		}
207 		if (req.perout.index >= ops->n_per_out) {
208 			err = -EINVAL;
209 			break;
210 		}
211 		req.type = PTP_CLK_REQ_PEROUT;
212 		enable = req.perout.period.sec || req.perout.period.nsec;
213 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
214 			return -ERESTARTSYS;
215 		err = ops->enable(ops, &req, enable);
216 		mutex_unlock(&ptp->pincfg_mux);
217 		break;
218 
219 	case PTP_ENABLE_PPS:
220 	case PTP_ENABLE_PPS2:
221 		memset(&req, 0, sizeof(req));
222 
223 		if (!capable(CAP_SYS_TIME))
224 			return -EPERM;
225 		req.type = PTP_CLK_REQ_PPS;
226 		enable = arg ? 1 : 0;
227 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
228 			return -ERESTARTSYS;
229 		err = ops->enable(ops, &req, enable);
230 		mutex_unlock(&ptp->pincfg_mux);
231 		break;
232 
233 	case PTP_SYS_OFFSET_PRECISE:
234 	case PTP_SYS_OFFSET_PRECISE2:
235 		if (!ptp->info->getcrosststamp) {
236 			err = -EOPNOTSUPP;
237 			break;
238 		}
239 		err = ptp->info->getcrosststamp(ptp->info, &xtstamp);
240 		if (err)
241 			break;
242 
243 		memset(&precise_offset, 0, sizeof(precise_offset));
244 		ts = ktime_to_timespec64(xtstamp.device);
245 		precise_offset.device.sec = ts.tv_sec;
246 		precise_offset.device.nsec = ts.tv_nsec;
247 		ts = ktime_to_timespec64(xtstamp.sys_realtime);
248 		precise_offset.sys_realtime.sec = ts.tv_sec;
249 		precise_offset.sys_realtime.nsec = ts.tv_nsec;
250 		ts = ktime_to_timespec64(xtstamp.sys_monoraw);
251 		precise_offset.sys_monoraw.sec = ts.tv_sec;
252 		precise_offset.sys_monoraw.nsec = ts.tv_nsec;
253 		if (copy_to_user((void __user *)arg, &precise_offset,
254 				 sizeof(precise_offset)))
255 			err = -EFAULT;
256 		break;
257 
258 	case PTP_SYS_OFFSET_EXTENDED:
259 	case PTP_SYS_OFFSET_EXTENDED2:
260 		if (!ptp->info->gettimex64) {
261 			err = -EOPNOTSUPP;
262 			break;
263 		}
264 		extoff = memdup_user((void __user *)arg, sizeof(*extoff));
265 		if (IS_ERR(extoff)) {
266 			err = PTR_ERR(extoff);
267 			extoff = NULL;
268 			break;
269 		}
270 		if (extoff->n_samples > PTP_MAX_SAMPLES
271 		    || extoff->rsv[0] || extoff->rsv[1] || extoff->rsv[2]) {
272 			err = -EINVAL;
273 			break;
274 		}
275 		for (i = 0; i < extoff->n_samples; i++) {
276 			err = ptp->info->gettimex64(ptp->info, &ts, &sts);
277 			if (err)
278 				goto out;
279 			extoff->ts[i][0].sec = sts.pre_ts.tv_sec;
280 			extoff->ts[i][0].nsec = sts.pre_ts.tv_nsec;
281 			extoff->ts[i][1].sec = ts.tv_sec;
282 			extoff->ts[i][1].nsec = ts.tv_nsec;
283 			extoff->ts[i][2].sec = sts.post_ts.tv_sec;
284 			extoff->ts[i][2].nsec = sts.post_ts.tv_nsec;
285 		}
286 		if (copy_to_user((void __user *)arg, extoff, sizeof(*extoff)))
287 			err = -EFAULT;
288 		break;
289 
290 	case PTP_SYS_OFFSET:
291 	case PTP_SYS_OFFSET2:
292 		sysoff = memdup_user((void __user *)arg, sizeof(*sysoff));
293 		if (IS_ERR(sysoff)) {
294 			err = PTR_ERR(sysoff);
295 			sysoff = NULL;
296 			break;
297 		}
298 		if (sysoff->n_samples > PTP_MAX_SAMPLES) {
299 			err = -EINVAL;
300 			break;
301 		}
302 		pct = &sysoff->ts[0];
303 		for (i = 0; i < sysoff->n_samples; i++) {
304 			ktime_get_real_ts64(&ts);
305 			pct->sec = ts.tv_sec;
306 			pct->nsec = ts.tv_nsec;
307 			pct++;
308 			if (ops->gettimex64)
309 				err = ops->gettimex64(ops, &ts, NULL);
310 			else
311 				err = ops->gettime64(ops, &ts);
312 			if (err)
313 				goto out;
314 			pct->sec = ts.tv_sec;
315 			pct->nsec = ts.tv_nsec;
316 			pct++;
317 		}
318 		ktime_get_real_ts64(&ts);
319 		pct->sec = ts.tv_sec;
320 		pct->nsec = ts.tv_nsec;
321 		if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff)))
322 			err = -EFAULT;
323 		break;
324 
325 	case PTP_PIN_GETFUNC:
326 	case PTP_PIN_GETFUNC2:
327 		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
328 			err = -EFAULT;
329 			break;
330 		}
331 		if ((pd.rsv[0] || pd.rsv[1] || pd.rsv[2]
332 				|| pd.rsv[3] || pd.rsv[4])
333 			&& cmd == PTP_PIN_GETFUNC2) {
334 			err = -EINVAL;
335 			break;
336 		} else if (cmd == PTP_PIN_GETFUNC) {
337 			pd.rsv[0] = 0;
338 			pd.rsv[1] = 0;
339 			pd.rsv[2] = 0;
340 			pd.rsv[3] = 0;
341 			pd.rsv[4] = 0;
342 		}
343 		pin_index = pd.index;
344 		if (pin_index >= ops->n_pins) {
345 			err = -EINVAL;
346 			break;
347 		}
348 		pin_index = array_index_nospec(pin_index, ops->n_pins);
349 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
350 			return -ERESTARTSYS;
351 		pd = ops->pin_config[pin_index];
352 		mutex_unlock(&ptp->pincfg_mux);
353 		if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
354 			err = -EFAULT;
355 		break;
356 
357 	case PTP_PIN_SETFUNC:
358 	case PTP_PIN_SETFUNC2:
359 		if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
360 			err = -EFAULT;
361 			break;
362 		}
363 		if ((pd.rsv[0] || pd.rsv[1] || pd.rsv[2]
364 				|| pd.rsv[3] || pd.rsv[4])
365 			&& cmd == PTP_PIN_SETFUNC2) {
366 			err = -EINVAL;
367 			break;
368 		} else if (cmd == PTP_PIN_SETFUNC) {
369 			pd.rsv[0] = 0;
370 			pd.rsv[1] = 0;
371 			pd.rsv[2] = 0;
372 			pd.rsv[3] = 0;
373 			pd.rsv[4] = 0;
374 		}
375 		pin_index = pd.index;
376 		if (pin_index >= ops->n_pins) {
377 			err = -EINVAL;
378 			break;
379 		}
380 		pin_index = array_index_nospec(pin_index, ops->n_pins);
381 		if (mutex_lock_interruptible(&ptp->pincfg_mux))
382 			return -ERESTARTSYS;
383 		err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
384 		mutex_unlock(&ptp->pincfg_mux);
385 		break;
386 
387 	default:
388 		err = -ENOTTY;
389 		break;
390 	}
391 
392 out:
393 	kfree(extoff);
394 	kfree(sysoff);
395 	return err;
396 }
397 
398 __poll_t ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
399 {
400 	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
401 
402 	poll_wait(fp, &ptp->tsev_wq, wait);
403 
404 	return queue_cnt(&ptp->tsevq) ? EPOLLIN : 0;
405 }
406 
407 #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
408 
409 ssize_t ptp_read(struct posix_clock *pc,
410 		 uint rdflags, char __user *buf, size_t cnt)
411 {
412 	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
413 	struct timestamp_event_queue *queue = &ptp->tsevq;
414 	struct ptp_extts_event *event;
415 	unsigned long flags;
416 	size_t qcnt, i;
417 	int result;
418 
419 	if (cnt % sizeof(struct ptp_extts_event) != 0)
420 		return -EINVAL;
421 
422 	if (cnt > EXTTS_BUFSIZE)
423 		cnt = EXTTS_BUFSIZE;
424 
425 	cnt = cnt / sizeof(struct ptp_extts_event);
426 
427 	if (mutex_lock_interruptible(&ptp->tsevq_mux))
428 		return -ERESTARTSYS;
429 
430 	if (wait_event_interruptible(ptp->tsev_wq,
431 				     ptp->defunct || queue_cnt(queue))) {
432 		mutex_unlock(&ptp->tsevq_mux);
433 		return -ERESTARTSYS;
434 	}
435 
436 	if (ptp->defunct) {
437 		mutex_unlock(&ptp->tsevq_mux);
438 		return -ENODEV;
439 	}
440 
441 	event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
442 	if (!event) {
443 		mutex_unlock(&ptp->tsevq_mux);
444 		return -ENOMEM;
445 	}
446 
447 	spin_lock_irqsave(&queue->lock, flags);
448 
449 	qcnt = queue_cnt(queue);
450 
451 	if (cnt > qcnt)
452 		cnt = qcnt;
453 
454 	for (i = 0; i < cnt; i++) {
455 		event[i] = queue->buf[queue->head];
456 		queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
457 	}
458 
459 	spin_unlock_irqrestore(&queue->lock, flags);
460 
461 	cnt = cnt * sizeof(struct ptp_extts_event);
462 
463 	mutex_unlock(&ptp->tsevq_mux);
464 
465 	result = cnt;
466 	if (copy_to_user(buf, event, cnt))
467 		result = -EFAULT;
468 
469 	kfree(event);
470 	return result;
471 }
472