summaryrefslogtreecommitdiffstats
path: root/drivers/net/ethernet/ti/cpts.c
blob: 054f78295d1d4834a7cff29e2469c2072c4f2f51 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
/*
 * TI Common Platform Time Sync
 *
 * Copyright (C) 2012 Richard Cochran <richardcochran@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#include <linux/err.h>
#include <linux/if.h>
#include <linux/hrtimer.h>
#include <linux/module.h>
#include <linux/net_tstamp.h>
#include <linux/ptp_classify.h>
#include <linux/time.h>
#include <linux/uaccess.h>
#include <linux/workqueue.h>
#include <linux/if_ether.h>
#include <linux/if_vlan.h>

#include "cpts.h"

#define CPTS_SKB_TX_WORK_TIMEOUT 1 /* jiffies */

struct cpts_skb_cb_data {
	unsigned long tmo;
};

#define cpts_read32(c, r)	readl_relaxed(&c->reg->r)
#define cpts_write32(c, v, r)	writel_relaxed(v, &c->reg->r)

static int cpts_match(struct sk_buff *skb, unsigned int ptp_class,
		      u16 ts_seqid, u8 ts_msgtype);

static int event_expired(struct cpts_event *event)
{
	return time_after(jiffies, event->tmo);
}

static int event_type(struct cpts_event *event)
{
	return (event->high >> EVENT_TYPE_SHIFT) & EVENT_TYPE_MASK;
}

static int cpts_fifo_pop(struct cpts *cpts, u32 *high, u32 *low)
{
	u32 r = cpts_read32(cpts, intstat_raw);

	if (r & TS_PEND_RAW) {
		*high = cpts_read32(cpts, event_high);
		*low  = cpts_read32(cpts, event_low);
		cpts_write32(cpts, EVENT_POP, event_pop);
		return 0;
	}
	return -1;
}

static int cpts_purge_events(struct cpts *cpts)
{
	struct list_head *this, *next;
	struct cpts_event *event;
	int removed = 0;

	list_for_each_safe(this, next, &cpts->events) {
		event = list_entry(this, struct cpts_event, list);
		if (event_expired(event)) {
			list_del_init(&event->list);
			list_add(&event->list, &cpts->pool);
			++removed;
		}
	}

	if (removed)
		pr_debug("cpts: event pool cleaned up %d\n", removed);
	return removed ? 0 : -1;
}

static void cpts_purge_txq(struct cpts *cpts)
{
	struct cpts_skb_cb_data *skb_cb;
	struct sk_buff *skb, *tmp;
	int removed = 0;

	skb_queue_walk_safe(&cpts->txq, skb, tmp) {
		skb_cb = (struct cpts_skb_cb_data *)skb->cb;
		if (time_after(jiffies, skb_cb->tmo)) {
			__skb_unlink(skb, &cpts->txq);
			dev_consume_skb_any(skb);
			++removed;
		}
	}

	if (removed)
		dev_dbg(cpts->dev, "txq cleaned up %d\n", removed);
}

static bool cpts_match_tx_ts(struct cpts *cpts, struct cpts_event *event)
{
	struct sk_buff *skb, *tmp;
	u16 seqid;
	u8 mtype;
	bool found = false;

	mtype = (event->high >> MESSAGE_TYPE_SHIFT) & MESSAGE_TYPE_MASK;
	seqid = (event->high >> SEQUENCE_ID_SHIFT) & SEQUENCE_ID_MASK;

	/* no need to grab txq.lock as access is always done under cpts->lock */
	skb_queue_walk_safe(&cpts->txq, skb, tmp) {
		struct skb_shared_hwtstamps ssh;
		unsigned int class = ptp_classify_raw(skb);
		struct cpts_skb_cb_data *skb_cb =
					(struct cpts_skb_cb_data *)skb->cb;

		if (cpts_match(skb, class, seqid, mtype)) {
			u64 ns = timecounter_cyc2time(&cpts->tc, event->low);

			memset(&ssh, 0, sizeof(ssh));
			ssh.hwtstamp = ns_to_ktime(ns);
			skb_tstamp_tx(skb, &ssh);
			found = true;
			__skb_unlink(skb, &cpts->txq);
			dev_consume_skb_any(skb);
			dev_dbg(cpts->dev, "match tx timestamp mtype %u seqid %04x\n",
				mtype, seqid);
			break;
		}

		if (time_after(jiffies, skb_cb->tmo)) {
			/* timeout any expired skbs over 1s */
			dev_dbg(cpts->dev, "expiring tx timestamp from txq\n");
			__skb_unlink(skb, &cpts->txq);
			dev_consume_skb_any(skb);
		}
	}

	return found;
}

/*
 * Returns zero if matching event type was found.
 */
static int cpts_fifo_read(struct cpts *cpts, int match)
{
	int i, type = -1;
	u32 hi, lo;
	struct cpts_event *event;

	for (i = 0; i < CPTS_FIFO_DEPTH; i++) {
		if (cpts_fifo_pop(cpts, &hi, &lo))
			break;

		if (list_empty(&cpts->pool) && cpts_purge_events(cpts)) {
			pr_err("cpts: event pool empty\n");
			return -1;
		}

		event = list_first_entry(&cpts->pool, struct cpts_event, list);
		event->tmo = jiffies + 2;
		event->high = hi;
		event->low = lo;
		type = event_type(event);
		switch (type) {
		case CPTS_EV_TX:
			if (cpts_match_tx_ts(cpts, event)) {
				/* if the new event matches an existing skb,
				 * then don't queue it
				 */
				break;
			}
			/* fall through */
		case CPTS_EV_PUSH:
		case CPTS_EV_RX:
			list_del_init(&event->list);
			list_add_tail(&event->list, &cpts->events);
			break;
		case CPTS_EV_ROLL:
		case CPTS_EV_HALF:
		case CPTS_EV_HW:
			break;
		default:
			pr_err("cpts: unknown event type\n");
			break;
		}
		if (type == match)
			break;
	}
	return type == match ? 0 : -1;
}

static u64 cpts_systim_read(const struct cyclecounter *cc)
{
	u64 val = 0;
	struct cpts_event *event;
	struct list_head *this, *next;
	struct cpts *cpts = container_of(cc, struct cpts, cc);

	cpts_write32(cpts, TS_PUSH, ts_push);
	if (cpts_fifo_read(cpts, CPTS_EV_PUSH))
		pr_err("cpts: unable to obtain a time stamp\n");

	list_for_each_safe(this, next, &cpts->events) {
		event = list_entry(this, struct cpts_event, list);
		if (event_type(event) == CPTS_EV_PUSH) {
			list_del_init(&event->list);
			list_add(&event->list, &cpts->pool);
			val = event->low;
			break;
		}
	}

	return val;
}

/* PTP clock operations */

static int cpts_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
{
	u64 adj;
	u32 diff, mult;
	int neg_adj = 0;
	unsigned long flags;
	struct cpts *cpts = container_of(ptp, struct cpts, info);

	if (ppb < 0) {
		neg_adj = 1;
		ppb = -ppb;
	}
	mult = cpts->cc_mult;
	adj = mult;
	adj *= ppb;
	diff = div_u64(adj, 1000000000ULL);

	spin_lock_irqsave(&cpts->lock, flags);

	timecounter_read(&cpts->tc);

	cpts->cc.mult = neg_adj ? mult - diff : mult + diff;

	spin_unlock_irqrestore(&cpts->lock, flags);

	return 0;
}

static int cpts_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
{
	unsigned long flags;
	struct cpts *cpts = container_of(ptp, struct cpts, info);

	spin_lock_irqsave(&cpts->lock, flags);
	timecounter_adjtime(&cpts->tc, delta);
	spin_unlock_irqrestore(&cpts->lock, flags);

	return 0;
}

static int cpts_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
{
	u64 ns;
	unsigned long flags;
	struct cpts *cpts = container_of(ptp, struct cpts, info);

	spin_lock_irqsave(&cpts->lock, flags);
	ns = timecounter_read(&cpts->tc);
	spin_unlock_irqrestore(&cpts->lock, flags);

	*ts = ns_to_timespec64(ns);

	return 0;
}

static int cpts_ptp_settime(struct ptp_clock_info *ptp,
			    const struct timespec64 *ts)
{
	u64 ns;
	unsigned long flags;
	struct cpts *cpts = container_of(ptp, struct cpts, info);

	ns = timespec64_to_ns(ts);

	spin_lock_irqsave(&cpts->lock, flags);
	timecounter_init(&cpts->tc, &cpts->cc, ns);
	spin_unlock_irqrestore(&cpts->lock, flags);

	return 0;
}

static int cpts_ptp_enable(struct ptp_clock_info *ptp,
			   struct ptp_clock_request *rq, int on)
{
	return -EOPNOTSUPP;
}

static long cpts_overflow_check(struct ptp_clock_info *ptp)
{
	struct cpts *cpts = container_of(ptp, struct cpts, info);
	unsigned long delay = cpts->ov_check_period;
	struct timespec64 ts;
	unsigned long flags;

	spin_lock_irqsave(&cpts->lock, flags);
	ts = ns_to_timespec64(timecounter_read(&cpts->tc));

	if (!skb_queue_empty(&cpts->txq)) {
		cpts_purge_txq(cpts);
		if (!skb_queue_empty(&cpts->txq))
			delay = CPTS_SKB_TX_WORK_TIMEOUT;
	}
	spin_unlock_irqrestore(&cpts->lock, flags);

	pr_debug("cpts overflow check at %lld.%09ld\n",
		 (long long)ts.tv_sec, ts.tv_nsec);
	return (long)delay;
}

static const struct ptp_clock_info cpts_info = {
	.owner		= THIS_MODULE,
	.name		= "CTPS timer",
	.max_adj	= 1000000,
	.n_ext_ts	= 0,
	.n_pins		= 0,
	.pps		= 0,
	.adjfreq	= cpts_ptp_adjfreq,
	.adjtime	= cpts_ptp_adjtime,
	.gettime64	= cpts_ptp_gettime,
	.settime64	= cpts_ptp_settime,
	.enable		= cpts_ptp_enable,
	.do_aux_work	= cpts_overflow_check,
};

static int cpts_match(struct sk_buff *skb, unsigned int ptp_class,
		      u16 ts_seqid, u8 ts_msgtype)
{
	u16 *seqid;
	unsigned int offset = 0;
	u8 *msgtype, *data = skb->data;

	if (ptp_class & PTP_CLASS_VLAN)
		offset += VLAN_HLEN;

	switch (ptp_class & PTP_CLASS_PMASK) {
	case PTP_CLASS_IPV4:
		offset += ETH_HLEN + IPV4_HLEN(data + offset) + UDP_HLEN;
		break;
	case PTP_CLASS_IPV6:
		offset += ETH_HLEN + IP6_HLEN + UDP_HLEN;
		break;
	case PTP_CLASS_L2:
		offset += ETH_HLEN;
		break;
	default:
		return 0;
	}

	if (skb->len + ETH_HLEN < offset + OFF_PTP_SEQUENCE_ID + sizeof(*seqid))
		return 0;

	if (unlikely(ptp_class & PTP_CLASS_V1))
		msgtype = data + offset + OFF_PTP_CONTROL;
	else
		msgtype = data + offset;

	seqid = (u16 *)(data + offset + OFF_PTP_SEQUENCE_ID);

	return (ts_msgtype == (*msgtype & 0xf) && ts_seqid == ntohs(*seqid));
}

static u64 cpts_find_ts(struct cpts *cpts, struct sk_buff *skb, int ev_type)
{
	u64 ns = 0;
	struct cpts_event *event;
	struct list_head *this, *next;
	unsigned int class = ptp_classify_raw(skb);
	unsigned long flags;
	u16 seqid;
	u8 mtype;

	if (class == PTP_CLASS_NONE)
		return 0;

	spin_lock_irqsave(&cpts->lock, flags);
	cpts_fifo_read(cpts, -1);
	list_for_each_safe(this, next, &cpts->events) {
		event = list_entry(this, struct cpts_event, list);
		if (event_expired(event)) {
			list_del_init(&event->list);
			list_add(&event->list, &cpts->pool);
			continue;
		}
		mtype = (event->high >> MESSAGE_TYPE_SHIFT) & MESSAGE_TYPE_MASK;
		seqid = (event->high >> SEQUENCE_ID_SHIFT) & SEQUENCE_ID_MASK;
		if (ev_type == event_type(event) &&
		    cpts_match(skb, class, seqid, mtype)) {
			ns = timecounter_cyc2time(&cpts->tc, event->low);
			list_del_init(&event->list);
			list_add(&event->list, &cpts->pool);
			break;
		}
	}

	if (ev_type == CPTS_EV_TX && !ns) {
		struct cpts_skb_cb_data *skb_cb =
				(struct cpts_skb_cb_data *)skb->cb;
		/* Not found, add frame to queue for processing later.
		 * The periodic FIFO check will handle this.
		 */
		skb_get(skb);
		/* get the timestamp for timeouts */
		skb_cb->tmo = jiffies + msecs_to_jiffies(100);
		__skb_queue_tail(&cpts->txq, skb);
		ptp_schedule_worker(cpts->clock, 0);
	}
	spin_unlock_irqrestore(&cpts->lock, flags);

	return ns;
}

void cpts_rx_timestamp(struct cpts *cpts, struct sk_buff *skb)
{
	u64 ns;
	struct skb_shared_hwtstamps *ssh;

	ns = cpts_find_ts(cpts, skb, CPTS_EV_RX);
	if (!ns)
		return;
	ssh = skb_hwtstamps(skb);
	memset(ssh, 0, sizeof(*ssh));
	ssh->hwtstamp = ns_to_ktime(ns);
}
EXPORT_SYMBOL_GPL(cpts_rx_timestamp);

void cpts_tx_timestamp(struct cpts *cpts, struct sk_buff *skb)
{
	u64 ns;
	struct skb_shared_hwtstamps ssh;

	if (!(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
		return;
	ns = cpts_find_ts(cpts, skb, CPTS_EV_TX);
	if (!ns)
		return;
	memset(&ssh, 0, sizeof(ssh));
	ssh.hwtstamp = ns_to_ktime(ns);
	skb_tstamp_tx(skb, &ssh);
}
EXPORT_SYMBOL_GPL(cpts_tx_timestamp);

int cpts_register(struct cpts *cpts)
{
	int err, i;

	skb_queue_head_init(&cpts->txq);
	INIT_LIST_HEAD(&cpts->events);
	INIT_LIST_HEAD(&cpts->pool);
	for (i = 0; i < CPTS_MAX_EVENTS; i++)
		list_add(&cpts->pool_data[i].list, &cpts->pool);

	clk_enable(cpts->refclk);

	cpts_write32(cpts, CPTS_EN, control);
	cpts_write32(cpts, TS_PEND_EN, int_enable);

	timecounter_init(&cpts->tc, &cpts->cc, ktime_to_ns(ktime_get_real()));

	cpts->clock = ptp_clock_register(&cpts->info, cpts->dev);
	if (IS_ERR(cpts->clock)) {
		err = PTR_ERR(cpts->clock);
		cpts->clock = NULL;
		goto err_ptp;
	}
	cpts->phc_index = ptp_clock_index(cpts->clock);

	ptp_schedule_worker(cpts->clock, cpts->ov_check_period);
	return 0;

err_ptp:
	clk_disable(cpts->refclk);
	return err;
}
EXPORT_SYMBOL_GPL(cpts_register);

void cpts_unregister(struct cpts *cpts)
{
	if (WARN_ON(!cpts->clock))
		return;

	ptp_clock_unregister(cpts->clock);
	cpts->clock = NULL;

	cpts_write32(cpts, 0, int_enable);
	cpts_write32(cpts, 0, control);

	/* Drop all packet */
	skb_queue_purge(&cpts->txq);

	clk_disable(cpts->refclk);
}
EXPORT_SYMBOL_GPL(cpts_unregister);

static void cpts_calc_mult_shift(struct cpts *cpts)
{
	u64 frac, maxsec, ns;
	u32 freq;

	freq = clk_get_rate(cpts->refclk);

	/* Calc the maximum number of seconds which we can run before
	 * wrapping around.
	 */
	maxsec = cpts->cc.mask;
	do_div(maxsec, freq);
	/* limit conversation rate to 10 sec as higher values will produce
	 * too small mult factors and so reduce the conversion accuracy
	 */
	if (maxsec > 10)
		maxsec = 10;

	/* Calc overflow check period (maxsec / 2) */
	cpts->ov_check_period = (HZ * maxsec) / 2;
	dev_info(cpts->dev, "cpts: overflow check period %lu (jiffies)\n",
		 cpts->ov_check_period);

	if (cpts->cc.mult || cpts->cc.shift)
		return;

	clocks_calc_mult_shift(&cpts->cc.mult, &cpts->cc.shift,
			       freq, NSEC_PER_SEC, maxsec);

	frac = 0;
	ns = cyclecounter_cyc2ns(&cpts->cc, freq, cpts->cc.mask, &frac);

	dev_info(cpts->dev,
		 "CPTS: ref_clk_freq:%u calc_mult:%u calc_shift:%u error:%lld nsec/sec\n",
		 freq, cpts->cc.mult, cpts->cc.shift, (ns - NSEC_PER_SEC));
}

static int cpts_of_parse(struct cpts *cpts, struct device_node *node)
{
	int ret = -EINVAL;
	u32 prop;

	if (!of_property_read_u32(node, "cpts_clock_mult", &prop))
		cpts->cc.mult = prop;

	if (!of_property_read_u32(node, "cpts_clock_shift", &prop))
		cpts->cc.shift = prop;

	if ((cpts->cc.mult && !cpts->cc.shift) ||
	    (!cpts->cc.mult && cpts->cc.shift))
		goto of_error;

	return 0;

of_error:
	dev_err(cpts->dev, "CPTS: Missing property in the DT.\n");
	return ret;
}

struct cpts *cpts_create(struct device *dev, void __iomem *regs,
			 struct device_node *node)
{
	struct cpts *cpts;
	int ret;

	cpts = devm_kzalloc(dev, sizeof(*cpts), GFP_KERNEL);
	if (!cpts)
		return ERR_PTR(-ENOMEM);

	cpts->dev = dev;
	cpts->reg = (struct cpsw_cpts __iomem *)regs;
	spin_lock_init(&cpts->lock);

	ret = cpts_of_parse(cpts, node);
	if (ret)
		return ERR_PTR(ret);

	cpts->refclk = devm_clk_get(dev, "cpts");
	if (IS_ERR(cpts->refclk)) {
		dev_err(dev, "Failed to get cpts refclk\n");
		return ERR_CAST(cpts->refclk);
	}

	clk_prepare(cpts->refclk);

	cpts->cc.read = cpts_systim_read;
	cpts->cc.mask = CLOCKSOURCE_MASK(32);
	cpts->info = cpts_info;

	cpts_calc_mult_shift(cpts);
	/* save cc.mult original value as it can be modified
	 * by cpts_ptp_adjfreq().
	 */
	cpts->cc_mult = cpts->cc.mult;

	return cpts;
}
EXPORT_SYMBOL_GPL(cpts_create);

void cpts_release(struct cpts *cpts)
{
	if (!cpts)
		return;

	if (WARN_ON(!cpts->refclk))
		return;

	clk_unprepare(cpts->refclk);
}
EXPORT_SYMBOL_GPL(cpts_release);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("TI CPTS driver");
MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");