xref: /openbmc/linux/drivers/net/ethernet/ti/cpts.c (revision a4539207)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * TI Common Platform Time Sync
4  *
5  * Copyright (C) 2012 Richard Cochran <richardcochran@gmail.com>
6  *
7  */
8 #include <linux/clk-provider.h>
9 #include <linux/err.h>
10 #include <linux/if.h>
11 #include <linux/hrtimer.h>
12 #include <linux/module.h>
13 #include <linux/net_tstamp.h>
14 #include <linux/ptp_classify.h>
15 #include <linux/time.h>
16 #include <linux/uaccess.h>
17 #include <linux/workqueue.h>
18 #include <linux/if_ether.h>
19 #include <linux/if_vlan.h>
20 
21 #include "cpts.h"
22 
23 #define CPTS_SKB_TX_WORK_TIMEOUT 1 /* jiffies */
24 #define CPTS_SKB_RX_TX_TMO 100 /*ms */
25 #define CPTS_EVENT_RX_TX_TIMEOUT (100) /* ms */
26 
27 struct cpts_skb_cb_data {
28 	u32 skb_mtype_seqid;
29 	unsigned long tmo;
30 };
31 
32 #define cpts_read32(c, r)	readl_relaxed(&c->reg->r)
33 #define cpts_write32(c, v, r)	writel_relaxed(v, &c->reg->r)
34 
cpts_event_port(struct cpts_event * event)35 static int cpts_event_port(struct cpts_event *event)
36 {
37 	return (event->high >> PORT_NUMBER_SHIFT) & PORT_NUMBER_MASK;
38 }
39 
event_expired(struct cpts_event * event)40 static int event_expired(struct cpts_event *event)
41 {
42 	return time_after(jiffies, event->tmo);
43 }
44 
event_type(struct cpts_event * event)45 static int event_type(struct cpts_event *event)
46 {
47 	return (event->high >> EVENT_TYPE_SHIFT) & EVENT_TYPE_MASK;
48 }
49 
cpts_fifo_pop(struct cpts * cpts,u32 * high,u32 * low)50 static int cpts_fifo_pop(struct cpts *cpts, u32 *high, u32 *low)
51 {
52 	u32 r = cpts_read32(cpts, intstat_raw);
53 
54 	if (r & TS_PEND_RAW) {
55 		*high = cpts_read32(cpts, event_high);
56 		*low  = cpts_read32(cpts, event_low);
57 		cpts_write32(cpts, EVENT_POP, event_pop);
58 		return 0;
59 	}
60 	return -1;
61 }
62 
cpts_purge_events(struct cpts * cpts)63 static int cpts_purge_events(struct cpts *cpts)
64 {
65 	struct list_head *this, *next;
66 	struct cpts_event *event;
67 	int removed = 0;
68 
69 	list_for_each_safe(this, next, &cpts->events) {
70 		event = list_entry(this, struct cpts_event, list);
71 		if (event_expired(event)) {
72 			list_del_init(&event->list);
73 			list_add(&event->list, &cpts->pool);
74 			++removed;
75 		}
76 	}
77 
78 	if (removed)
79 		dev_dbg(cpts->dev, "cpts: event pool cleaned up %d\n", removed);
80 	return removed ? 0 : -1;
81 }
82 
cpts_purge_txq(struct cpts * cpts)83 static void cpts_purge_txq(struct cpts *cpts)
84 {
85 	struct cpts_skb_cb_data *skb_cb;
86 	struct sk_buff *skb, *tmp;
87 	int removed = 0;
88 
89 	skb_queue_walk_safe(&cpts->txq, skb, tmp) {
90 		skb_cb = (struct cpts_skb_cb_data *)skb->cb;
91 		if (time_after(jiffies, skb_cb->tmo)) {
92 			__skb_unlink(skb, &cpts->txq);
93 			dev_consume_skb_any(skb);
94 			++removed;
95 		}
96 	}
97 
98 	if (removed)
99 		dev_dbg(cpts->dev, "txq cleaned up %d\n", removed);
100 }
101 
102 /*
103  * Returns zero if matching event type was found.
104  */
cpts_fifo_read(struct cpts * cpts,int match)105 static int cpts_fifo_read(struct cpts *cpts, int match)
106 {
107 	struct ptp_clock_event pevent;
108 	bool need_schedule = false;
109 	struct cpts_event *event;
110 	unsigned long flags;
111 	int i, type = -1;
112 	u32 hi, lo;
113 
114 	spin_lock_irqsave(&cpts->lock, flags);
115 
116 	for (i = 0; i < CPTS_FIFO_DEPTH; i++) {
117 		if (cpts_fifo_pop(cpts, &hi, &lo))
118 			break;
119 
120 		if (list_empty(&cpts->pool) && cpts_purge_events(cpts)) {
121 			dev_warn(cpts->dev, "cpts: event pool empty\n");
122 			break;
123 		}
124 
125 		event = list_first_entry(&cpts->pool, struct cpts_event, list);
126 		event->high = hi;
127 		event->low = lo;
128 		event->timestamp = timecounter_cyc2time(&cpts->tc, event->low);
129 		type = event_type(event);
130 
131 		dev_dbg(cpts->dev, "CPTS_EV: %d high:%08X low:%08x\n",
132 			type, event->high, event->low);
133 		switch (type) {
134 		case CPTS_EV_PUSH:
135 			WRITE_ONCE(cpts->cur_timestamp, lo);
136 			timecounter_read(&cpts->tc);
137 			if (cpts->mult_new) {
138 				cpts->cc.mult = cpts->mult_new;
139 				cpts->mult_new = 0;
140 			}
141 			if (!cpts->irq_poll)
142 				complete(&cpts->ts_push_complete);
143 			break;
144 		case CPTS_EV_TX:
145 		case CPTS_EV_RX:
146 			event->tmo = jiffies +
147 				msecs_to_jiffies(CPTS_EVENT_RX_TX_TIMEOUT);
148 
149 			list_del_init(&event->list);
150 			list_add_tail(&event->list, &cpts->events);
151 			need_schedule = true;
152 			break;
153 		case CPTS_EV_ROLL:
154 		case CPTS_EV_HALF:
155 			break;
156 		case CPTS_EV_HW:
157 			pevent.timestamp = event->timestamp;
158 			pevent.type = PTP_CLOCK_EXTTS;
159 			pevent.index = cpts_event_port(event) - 1;
160 			ptp_clock_event(cpts->clock, &pevent);
161 			break;
162 		default:
163 			dev_err(cpts->dev, "cpts: unknown event type\n");
164 			break;
165 		}
166 		if (type == match)
167 			break;
168 	}
169 
170 	spin_unlock_irqrestore(&cpts->lock, flags);
171 
172 	if (!cpts->irq_poll && need_schedule)
173 		ptp_schedule_worker(cpts->clock, 0);
174 
175 	return type == match ? 0 : -1;
176 }
177 
cpts_misc_interrupt(struct cpts * cpts)178 void cpts_misc_interrupt(struct cpts *cpts)
179 {
180 	cpts_fifo_read(cpts, -1);
181 }
182 EXPORT_SYMBOL_GPL(cpts_misc_interrupt);
183 
cpts_systim_read(const struct cyclecounter * cc)184 static u64 cpts_systim_read(const struct cyclecounter *cc)
185 {
186 	struct cpts *cpts = container_of(cc, struct cpts, cc);
187 
188 	return READ_ONCE(cpts->cur_timestamp);
189 }
190 
cpts_update_cur_time(struct cpts * cpts,int match,struct ptp_system_timestamp * sts)191 static void cpts_update_cur_time(struct cpts *cpts, int match,
192 				 struct ptp_system_timestamp *sts)
193 {
194 	unsigned long flags;
195 
196 	reinit_completion(&cpts->ts_push_complete);
197 
198 	/* use spin_lock_irqsave() here as it has to run very fast */
199 	spin_lock_irqsave(&cpts->lock, flags);
200 	ptp_read_system_prets(sts);
201 	cpts_write32(cpts, TS_PUSH, ts_push);
202 	cpts_read32(cpts, ts_push);
203 	ptp_read_system_postts(sts);
204 	spin_unlock_irqrestore(&cpts->lock, flags);
205 
206 	if (cpts->irq_poll && cpts_fifo_read(cpts, match) && match != -1)
207 		dev_err(cpts->dev, "cpts: unable to obtain a time stamp\n");
208 
209 	if (!cpts->irq_poll &&
210 	    !wait_for_completion_timeout(&cpts->ts_push_complete, HZ))
211 		dev_err(cpts->dev, "cpts: obtain a time stamp timeout\n");
212 }
213 
214 /* PTP clock operations */
215 
cpts_ptp_adjfine(struct ptp_clock_info * ptp,long scaled_ppm)216 static int cpts_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
217 {
218 	struct cpts *cpts = container_of(ptp, struct cpts, info);
219 
220 	mutex_lock(&cpts->ptp_clk_mutex);
221 
222 	cpts->mult_new = adjust_by_scaled_ppm(cpts->cc_mult, scaled_ppm);
223 
224 	cpts_update_cur_time(cpts, CPTS_EV_PUSH, NULL);
225 
226 	mutex_unlock(&cpts->ptp_clk_mutex);
227 	return 0;
228 }
229 
cpts_ptp_adjtime(struct ptp_clock_info * ptp,s64 delta)230 static int cpts_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
231 {
232 	struct cpts *cpts = container_of(ptp, struct cpts, info);
233 
234 	mutex_lock(&cpts->ptp_clk_mutex);
235 	timecounter_adjtime(&cpts->tc, delta);
236 	mutex_unlock(&cpts->ptp_clk_mutex);
237 
238 	return 0;
239 }
240 
cpts_ptp_gettimeex(struct ptp_clock_info * ptp,struct timespec64 * ts,struct ptp_system_timestamp * sts)241 static int cpts_ptp_gettimeex(struct ptp_clock_info *ptp,
242 			      struct timespec64 *ts,
243 			      struct ptp_system_timestamp *sts)
244 {
245 	struct cpts *cpts = container_of(ptp, struct cpts, info);
246 	u64 ns;
247 
248 	mutex_lock(&cpts->ptp_clk_mutex);
249 
250 	cpts_update_cur_time(cpts, CPTS_EV_PUSH, sts);
251 
252 	ns = timecounter_read(&cpts->tc);
253 	mutex_unlock(&cpts->ptp_clk_mutex);
254 
255 	*ts = ns_to_timespec64(ns);
256 
257 	return 0;
258 }
259 
cpts_ptp_settime(struct ptp_clock_info * ptp,const struct timespec64 * ts)260 static int cpts_ptp_settime(struct ptp_clock_info *ptp,
261 			    const struct timespec64 *ts)
262 {
263 	struct cpts *cpts = container_of(ptp, struct cpts, info);
264 	u64 ns;
265 
266 	ns = timespec64_to_ns(ts);
267 
268 	mutex_lock(&cpts->ptp_clk_mutex);
269 	timecounter_init(&cpts->tc, &cpts->cc, ns);
270 	mutex_unlock(&cpts->ptp_clk_mutex);
271 
272 	return 0;
273 }
274 
cpts_extts_enable(struct cpts * cpts,u32 index,int on)275 static int cpts_extts_enable(struct cpts *cpts, u32 index, int on)
276 {
277 	u32 v;
278 
279 	if (((cpts->hw_ts_enable & BIT(index)) >> index) == on)
280 		return 0;
281 
282 	mutex_lock(&cpts->ptp_clk_mutex);
283 
284 	v = cpts_read32(cpts, control);
285 	if (on) {
286 		v |= BIT(8 + index);
287 		cpts->hw_ts_enable |= BIT(index);
288 	} else {
289 		v &= ~BIT(8 + index);
290 		cpts->hw_ts_enable &= ~BIT(index);
291 	}
292 	cpts_write32(cpts, v, control);
293 
294 	mutex_unlock(&cpts->ptp_clk_mutex);
295 
296 	return 0;
297 }
298 
cpts_ptp_enable(struct ptp_clock_info * ptp,struct ptp_clock_request * rq,int on)299 static int cpts_ptp_enable(struct ptp_clock_info *ptp,
300 			   struct ptp_clock_request *rq, int on)
301 {
302 	struct cpts *cpts = container_of(ptp, struct cpts, info);
303 
304 	switch (rq->type) {
305 	case PTP_CLK_REQ_EXTTS:
306 		return cpts_extts_enable(cpts, rq->extts.index, on);
307 	default:
308 		break;
309 	}
310 
311 	return -EOPNOTSUPP;
312 }
313 
cpts_match_tx_ts(struct cpts * cpts,struct cpts_event * event)314 static bool cpts_match_tx_ts(struct cpts *cpts, struct cpts_event *event)
315 {
316 	struct sk_buff_head txq_list;
317 	struct sk_buff *skb, *tmp;
318 	unsigned long flags;
319 	bool found = false;
320 	u32 mtype_seqid;
321 
322 	mtype_seqid = event->high &
323 		      ((MESSAGE_TYPE_MASK << MESSAGE_TYPE_SHIFT) |
324 		       (SEQUENCE_ID_MASK << SEQUENCE_ID_SHIFT) |
325 		       (EVENT_TYPE_MASK << EVENT_TYPE_SHIFT));
326 
327 	__skb_queue_head_init(&txq_list);
328 
329 	spin_lock_irqsave(&cpts->txq.lock, flags);
330 	skb_queue_splice_init(&cpts->txq, &txq_list);
331 	spin_unlock_irqrestore(&cpts->txq.lock, flags);
332 
333 	skb_queue_walk_safe(&txq_list, skb, tmp) {
334 		struct skb_shared_hwtstamps ssh;
335 		struct cpts_skb_cb_data *skb_cb =
336 					(struct cpts_skb_cb_data *)skb->cb;
337 
338 		if (mtype_seqid == skb_cb->skb_mtype_seqid) {
339 			memset(&ssh, 0, sizeof(ssh));
340 			ssh.hwtstamp = ns_to_ktime(event->timestamp);
341 			skb_tstamp_tx(skb, &ssh);
342 			found = true;
343 			__skb_unlink(skb, &txq_list);
344 			dev_consume_skb_any(skb);
345 			dev_dbg(cpts->dev, "match tx timestamp mtype_seqid %08x\n",
346 				mtype_seqid);
347 			break;
348 		}
349 
350 		if (time_after(jiffies, skb_cb->tmo)) {
351 			/* timeout any expired skbs over 1s */
352 			dev_dbg(cpts->dev, "expiring tx timestamp from txq\n");
353 			__skb_unlink(skb, &txq_list);
354 			dev_consume_skb_any(skb);
355 		}
356 	}
357 
358 	spin_lock_irqsave(&cpts->txq.lock, flags);
359 	skb_queue_splice(&txq_list, &cpts->txq);
360 	spin_unlock_irqrestore(&cpts->txq.lock, flags);
361 
362 	return found;
363 }
364 
cpts_process_events(struct cpts * cpts)365 static void cpts_process_events(struct cpts *cpts)
366 {
367 	struct list_head *this, *next;
368 	struct cpts_event *event;
369 	LIST_HEAD(events_free);
370 	unsigned long flags;
371 	LIST_HEAD(events);
372 
373 	spin_lock_irqsave(&cpts->lock, flags);
374 	list_splice_init(&cpts->events, &events);
375 	spin_unlock_irqrestore(&cpts->lock, flags);
376 
377 	list_for_each_safe(this, next, &events) {
378 		event = list_entry(this, struct cpts_event, list);
379 		if (cpts_match_tx_ts(cpts, event) ||
380 		    time_after(jiffies, event->tmo)) {
381 			list_del_init(&event->list);
382 			list_add(&event->list, &events_free);
383 		}
384 	}
385 
386 	spin_lock_irqsave(&cpts->lock, flags);
387 	list_splice_tail(&events, &cpts->events);
388 	list_splice_tail(&events_free, &cpts->pool);
389 	spin_unlock_irqrestore(&cpts->lock, flags);
390 }
391 
cpts_overflow_check(struct ptp_clock_info * ptp)392 static long cpts_overflow_check(struct ptp_clock_info *ptp)
393 {
394 	struct cpts *cpts = container_of(ptp, struct cpts, info);
395 	unsigned long delay = cpts->ov_check_period;
396 	unsigned long flags;
397 	u64 ns;
398 
399 	mutex_lock(&cpts->ptp_clk_mutex);
400 
401 	cpts_update_cur_time(cpts, -1, NULL);
402 	ns = timecounter_read(&cpts->tc);
403 
404 	cpts_process_events(cpts);
405 
406 	spin_lock_irqsave(&cpts->txq.lock, flags);
407 	if (!skb_queue_empty(&cpts->txq)) {
408 		cpts_purge_txq(cpts);
409 		if (!skb_queue_empty(&cpts->txq))
410 			delay = CPTS_SKB_TX_WORK_TIMEOUT;
411 	}
412 	spin_unlock_irqrestore(&cpts->txq.lock, flags);
413 
414 	dev_dbg(cpts->dev, "cpts overflow check at %lld\n", ns);
415 	mutex_unlock(&cpts->ptp_clk_mutex);
416 	return (long)delay;
417 }
418 
419 static const struct ptp_clock_info cpts_info = {
420 	.owner		= THIS_MODULE,
421 	.name		= "CTPS timer",
422 	.max_adj	= 1000000,
423 	.n_ext_ts	= 0,
424 	.n_pins		= 0,
425 	.pps		= 0,
426 	.adjfine	= cpts_ptp_adjfine,
427 	.adjtime	= cpts_ptp_adjtime,
428 	.gettimex64	= cpts_ptp_gettimeex,
429 	.settime64	= cpts_ptp_settime,
430 	.enable		= cpts_ptp_enable,
431 	.do_aux_work	= cpts_overflow_check,
432 };
433 
cpts_skb_get_mtype_seqid(struct sk_buff * skb,u32 * mtype_seqid)434 static int cpts_skb_get_mtype_seqid(struct sk_buff *skb, u32 *mtype_seqid)
435 {
436 	unsigned int ptp_class = ptp_classify_raw(skb);
437 	struct ptp_header *hdr;
438 	u8 msgtype;
439 	u16 seqid;
440 
441 	if (ptp_class == PTP_CLASS_NONE)
442 		return 0;
443 
444 	hdr = ptp_parse_header(skb, ptp_class);
445 	if (!hdr)
446 		return 0;
447 
448 	msgtype = ptp_get_msgtype(hdr, ptp_class);
449 	seqid	= ntohs(hdr->sequence_id);
450 
451 	*mtype_seqid  = (msgtype & MESSAGE_TYPE_MASK) << MESSAGE_TYPE_SHIFT;
452 	*mtype_seqid |= (seqid & SEQUENCE_ID_MASK) << SEQUENCE_ID_SHIFT;
453 
454 	return 1;
455 }
456 
cpts_find_ts(struct cpts * cpts,struct sk_buff * skb,int ev_type,u32 skb_mtype_seqid)457 static u64 cpts_find_ts(struct cpts *cpts, struct sk_buff *skb,
458 			int ev_type, u32 skb_mtype_seqid)
459 {
460 	struct list_head *this, *next;
461 	struct cpts_event *event;
462 	unsigned long flags;
463 	u32 mtype_seqid;
464 	u64 ns = 0;
465 
466 	cpts_fifo_read(cpts, -1);
467 	spin_lock_irqsave(&cpts->lock, flags);
468 	list_for_each_safe(this, next, &cpts->events) {
469 		event = list_entry(this, struct cpts_event, list);
470 		if (event_expired(event)) {
471 			list_del_init(&event->list);
472 			list_add(&event->list, &cpts->pool);
473 			continue;
474 		}
475 
476 		mtype_seqid = event->high &
477 			      ((MESSAGE_TYPE_MASK << MESSAGE_TYPE_SHIFT) |
478 			       (SEQUENCE_ID_MASK << SEQUENCE_ID_SHIFT) |
479 			       (EVENT_TYPE_MASK << EVENT_TYPE_SHIFT));
480 
481 		if (mtype_seqid == skb_mtype_seqid) {
482 			ns = event->timestamp;
483 			list_del_init(&event->list);
484 			list_add(&event->list, &cpts->pool);
485 			break;
486 		}
487 	}
488 	spin_unlock_irqrestore(&cpts->lock, flags);
489 
490 	return ns;
491 }
492 
cpts_rx_timestamp(struct cpts * cpts,struct sk_buff * skb)493 void cpts_rx_timestamp(struct cpts *cpts, struct sk_buff *skb)
494 {
495 	struct cpts_skb_cb_data *skb_cb = (struct cpts_skb_cb_data *)skb->cb;
496 	struct skb_shared_hwtstamps *ssh;
497 	int ret;
498 	u64 ns;
499 
500 	/* cpts_rx_timestamp() is called before eth_type_trans(), so
501 	 * skb MAC Hdr properties are not configured yet. Hence need to
502 	 * reset skb MAC header here
503 	 */
504 	skb_reset_mac_header(skb);
505 	ret = cpts_skb_get_mtype_seqid(skb, &skb_cb->skb_mtype_seqid);
506 	if (!ret)
507 		return;
508 
509 	skb_cb->skb_mtype_seqid |= (CPTS_EV_RX << EVENT_TYPE_SHIFT);
510 
511 	dev_dbg(cpts->dev, "%s mtype seqid %08x\n",
512 		__func__, skb_cb->skb_mtype_seqid);
513 
514 	ns = cpts_find_ts(cpts, skb, CPTS_EV_RX, skb_cb->skb_mtype_seqid);
515 	if (!ns)
516 		return;
517 	ssh = skb_hwtstamps(skb);
518 	memset(ssh, 0, sizeof(*ssh));
519 	ssh->hwtstamp = ns_to_ktime(ns);
520 }
521 EXPORT_SYMBOL_GPL(cpts_rx_timestamp);
522 
cpts_tx_timestamp(struct cpts * cpts,struct sk_buff * skb)523 void cpts_tx_timestamp(struct cpts *cpts, struct sk_buff *skb)
524 {
525 	struct cpts_skb_cb_data *skb_cb = (struct cpts_skb_cb_data *)skb->cb;
526 	int ret;
527 
528 	if (!(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
529 		return;
530 
531 	ret = cpts_skb_get_mtype_seqid(skb, &skb_cb->skb_mtype_seqid);
532 	if (!ret)
533 		return;
534 
535 	skb_cb->skb_mtype_seqid |= (CPTS_EV_TX << EVENT_TYPE_SHIFT);
536 
537 	dev_dbg(cpts->dev, "%s mtype seqid %08x\n",
538 		__func__, skb_cb->skb_mtype_seqid);
539 
540 	/* Always defer TX TS processing to PTP worker */
541 	skb_get(skb);
542 	/* get the timestamp for timeouts */
543 	skb_cb->tmo = jiffies + msecs_to_jiffies(CPTS_SKB_RX_TX_TMO);
544 	skb_queue_tail(&cpts->txq, skb);
545 	ptp_schedule_worker(cpts->clock, 0);
546 }
547 EXPORT_SYMBOL_GPL(cpts_tx_timestamp);
548 
cpts_register(struct cpts * cpts)549 int cpts_register(struct cpts *cpts)
550 {
551 	int err, i;
552 
553 	skb_queue_head_init(&cpts->txq);
554 	INIT_LIST_HEAD(&cpts->events);
555 	INIT_LIST_HEAD(&cpts->pool);
556 	for (i = 0; i < CPTS_MAX_EVENTS; i++)
557 		list_add(&cpts->pool_data[i].list, &cpts->pool);
558 
559 	err = clk_enable(cpts->refclk);
560 	if (err)
561 		return err;
562 
563 	cpts_write32(cpts, CPTS_EN, control);
564 	cpts_write32(cpts, TS_PEND_EN, int_enable);
565 
566 	timecounter_init(&cpts->tc, &cpts->cc, ktime_get_real_ns());
567 
568 	cpts->clock = ptp_clock_register(&cpts->info, cpts->dev);
569 	if (IS_ERR(cpts->clock)) {
570 		err = PTR_ERR(cpts->clock);
571 		cpts->clock = NULL;
572 		goto err_ptp;
573 	}
574 	cpts->phc_index = ptp_clock_index(cpts->clock);
575 
576 	ptp_schedule_worker(cpts->clock, cpts->ov_check_period);
577 	return 0;
578 
579 err_ptp:
580 	clk_disable(cpts->refclk);
581 	return err;
582 }
583 EXPORT_SYMBOL_GPL(cpts_register);
584 
cpts_unregister(struct cpts * cpts)585 void cpts_unregister(struct cpts *cpts)
586 {
587 	if (WARN_ON(!cpts->clock))
588 		return;
589 
590 	ptp_clock_unregister(cpts->clock);
591 	cpts->clock = NULL;
592 	cpts->phc_index = -1;
593 
594 	cpts_write32(cpts, 0, int_enable);
595 	cpts_write32(cpts, 0, control);
596 
597 	/* Drop all packet */
598 	skb_queue_purge(&cpts->txq);
599 
600 	clk_disable(cpts->refclk);
601 }
602 EXPORT_SYMBOL_GPL(cpts_unregister);
603 
cpts_calc_mult_shift(struct cpts * cpts)604 static void cpts_calc_mult_shift(struct cpts *cpts)
605 {
606 	u64 frac, maxsec, ns;
607 	u32 freq;
608 
609 	freq = clk_get_rate(cpts->refclk);
610 
611 	/* Calc the maximum number of seconds which we can run before
612 	 * wrapping around.
613 	 */
614 	maxsec = cpts->cc.mask;
615 	do_div(maxsec, freq);
616 	/* limit conversation rate to 10 sec as higher values will produce
617 	 * too small mult factors and so reduce the conversion accuracy
618 	 */
619 	if (maxsec > 10)
620 		maxsec = 10;
621 
622 	/* Calc overflow check period (maxsec / 2) */
623 	cpts->ov_check_period = (HZ * maxsec) / 2;
624 	dev_info(cpts->dev, "cpts: overflow check period %lu (jiffies)\n",
625 		 cpts->ov_check_period);
626 
627 	if (cpts->cc.mult || cpts->cc.shift)
628 		return;
629 
630 	clocks_calc_mult_shift(&cpts->cc.mult, &cpts->cc.shift,
631 			       freq, NSEC_PER_SEC, maxsec);
632 
633 	frac = 0;
634 	ns = cyclecounter_cyc2ns(&cpts->cc, freq, cpts->cc.mask, &frac);
635 
636 	dev_info(cpts->dev,
637 		 "CPTS: ref_clk_freq:%u calc_mult:%u calc_shift:%u error:%lld nsec/sec\n",
638 		 freq, cpts->cc.mult, cpts->cc.shift, (ns - NSEC_PER_SEC));
639 }
640 
cpts_of_mux_clk_setup(struct cpts * cpts,struct device_node * node)641 static int cpts_of_mux_clk_setup(struct cpts *cpts, struct device_node *node)
642 {
643 	struct device_node *refclk_np;
644 	const char **parent_names;
645 	unsigned int num_parents;
646 	struct clk_hw *clk_hw;
647 	int ret = -EINVAL;
648 	u32 *mux_table;
649 
650 	refclk_np = of_get_child_by_name(node, "cpts-refclk-mux");
651 	if (!refclk_np)
652 		/* refclk selection supported not for all SoCs */
653 		return 0;
654 
655 	num_parents = of_clk_get_parent_count(refclk_np);
656 	if (num_parents < 1) {
657 		dev_err(cpts->dev, "mux-clock %s must have parents\n",
658 			refclk_np->name);
659 		goto mux_fail;
660 	}
661 
662 	parent_names = devm_kcalloc(cpts->dev, num_parents,
663 				    sizeof(*parent_names), GFP_KERNEL);
664 
665 	mux_table = devm_kcalloc(cpts->dev, num_parents, sizeof(*mux_table),
666 				 GFP_KERNEL);
667 	if (!mux_table || !parent_names) {
668 		ret = -ENOMEM;
669 		goto mux_fail;
670 	}
671 
672 	of_clk_parent_fill(refclk_np, parent_names, num_parents);
673 
674 	ret = of_property_read_variable_u32_array(refclk_np, "ti,mux-tbl",
675 						  mux_table,
676 						  num_parents, num_parents);
677 	if (ret < 0)
678 		goto mux_fail;
679 
680 	clk_hw = clk_hw_register_mux_table(cpts->dev, refclk_np->name,
681 					   parent_names, num_parents,
682 					   0,
683 					   &cpts->reg->rftclk_sel, 0, 0x1F,
684 					   0, mux_table, NULL);
685 	if (IS_ERR(clk_hw)) {
686 		ret = PTR_ERR(clk_hw);
687 		goto mux_fail;
688 	}
689 
690 	ret = devm_add_action_or_reset(cpts->dev,
691 				       (void(*)(void *))clk_hw_unregister_mux,
692 				       clk_hw);
693 	if (ret) {
694 		dev_err(cpts->dev, "add clkmux unreg action %d", ret);
695 		goto mux_fail;
696 	}
697 
698 	ret = of_clk_add_hw_provider(refclk_np, of_clk_hw_simple_get, clk_hw);
699 	if (ret)
700 		goto mux_fail;
701 
702 	ret = devm_add_action_or_reset(cpts->dev,
703 				       (void(*)(void *))of_clk_del_provider,
704 				       refclk_np);
705 	if (ret) {
706 		dev_err(cpts->dev, "add clkmux provider unreg action %d", ret);
707 		goto mux_fail;
708 	}
709 
710 	return ret;
711 
712 mux_fail:
713 	of_node_put(refclk_np);
714 	return ret;
715 }
716 
cpts_of_parse(struct cpts * cpts,struct device_node * node)717 static int cpts_of_parse(struct cpts *cpts, struct device_node *node)
718 {
719 	int ret = -EINVAL;
720 	u32 prop;
721 
722 	if (!of_property_read_u32(node, "cpts_clock_mult", &prop))
723 		cpts->cc.mult = prop;
724 
725 	if (!of_property_read_u32(node, "cpts_clock_shift", &prop))
726 		cpts->cc.shift = prop;
727 
728 	if ((cpts->cc.mult && !cpts->cc.shift) ||
729 	    (!cpts->cc.mult && cpts->cc.shift))
730 		goto of_error;
731 
732 	return cpts_of_mux_clk_setup(cpts, node);
733 
734 of_error:
735 	dev_err(cpts->dev, "CPTS: Missing property in the DT.\n");
736 	return ret;
737 }
738 
cpts_create(struct device * dev,void __iomem * regs,struct device_node * node,u32 n_ext_ts)739 struct cpts *cpts_create(struct device *dev, void __iomem *regs,
740 			 struct device_node *node, u32 n_ext_ts)
741 {
742 	struct cpts *cpts;
743 	int ret;
744 
745 	cpts = devm_kzalloc(dev, sizeof(*cpts), GFP_KERNEL);
746 	if (!cpts)
747 		return ERR_PTR(-ENOMEM);
748 
749 	cpts->dev = dev;
750 	cpts->reg = (struct cpsw_cpts __iomem *)regs;
751 	cpts->irq_poll = true;
752 	spin_lock_init(&cpts->lock);
753 	mutex_init(&cpts->ptp_clk_mutex);
754 	init_completion(&cpts->ts_push_complete);
755 
756 	ret = cpts_of_parse(cpts, node);
757 	if (ret)
758 		return ERR_PTR(ret);
759 
760 	cpts->refclk = devm_get_clk_from_child(dev, node, "cpts");
761 	if (IS_ERR(cpts->refclk))
762 		/* try get clk from dev node for compatibility */
763 		cpts->refclk = devm_clk_get(dev, "cpts");
764 
765 	if (IS_ERR(cpts->refclk)) {
766 		dev_err(dev, "Failed to get cpts refclk %ld\n",
767 			PTR_ERR(cpts->refclk));
768 		return ERR_CAST(cpts->refclk);
769 	}
770 
771 	ret = clk_prepare(cpts->refclk);
772 	if (ret)
773 		return ERR_PTR(ret);
774 
775 	cpts->cc.read = cpts_systim_read;
776 	cpts->cc.mask = CLOCKSOURCE_MASK(32);
777 	cpts->info = cpts_info;
778 	cpts->phc_index = -1;
779 
780 	if (n_ext_ts)
781 		cpts->info.n_ext_ts = n_ext_ts;
782 
783 	cpts_calc_mult_shift(cpts);
784 	/* save cc.mult original value as it can be modified
785 	 * by cpts_ptp_adjfine().
786 	 */
787 	cpts->cc_mult = cpts->cc.mult;
788 
789 	return cpts;
790 }
791 EXPORT_SYMBOL_GPL(cpts_create);
792 
cpts_release(struct cpts * cpts)793 void cpts_release(struct cpts *cpts)
794 {
795 	if (!cpts)
796 		return;
797 
798 	if (WARN_ON(!cpts->refclk))
799 		return;
800 
801 	clk_unprepare(cpts->refclk);
802 }
803 EXPORT_SYMBOL_GPL(cpts_release);
804 
805 MODULE_LICENSE("GPL v2");
806 MODULE_DESCRIPTION("TI CPTS driver");
807 MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
808