aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/net/dsa/sja1105/sja1105_ptp.c
blob: fac72af24baf57d0ad80c8a032904400663aeaa0 (plain) (blame)
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
624
625
626
627
628
629
630
631
632
633
634
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2019, Vladimir Oltean <olteanv@gmail.com>
 */
#include <linux/spi/spi.h>
#include "sja1105.h"

/* The adjfine API clamps ppb between [-32,768,000, 32,768,000], and
 * therefore scaled_ppm between [-2,147,483,648, 2,147,483,647].
 * Set the maximum supported ppb to a round value smaller than the maximum.
 *
 * Percentually speaking, this is a +/- 0.032x adjustment of the
 * free-running counter (0.968x to 1.032x).
 */
#define SJA1105_MAX_ADJ_PPB		32000000
#define SJA1105_SIZE_PTP_CMD		4

/*            This range is actually +/- SJA1105_MAX_ADJ_PPB
 *            divided by 1000 (ppb -> ppm) and with a 16-bit
 *            "fractional" part (actually fixed point).
 *                                    |
 *                                    v
 * Convert scaled_ppm from the +/- ((10^6) << 16) range
 * into the +/- (1 << 31) range.
 *
 * This forgoes a "ppb" numeric representation (up to NSEC_PER_SEC)
 * and defines the scaling factor between scaled_ppm and the actual
 * frequency adjustments of the PHC.
 *
 *   ptpclkrate = scaled_ppm * 2^31 / (10^6 * 2^16)
 *   simplifies to
 *   ptpclkrate = scaled_ppm * 2^9 / 5^6
 */
#define SJA1105_CC_MULT_NUM		(1 << 9)
#define SJA1105_CC_MULT_DEM		15625
#define SJA1105_CC_MULT			0x80000000

enum sja1105_ptp_clk_mode {
	PTP_ADD_MODE = 1,
	PTP_SET_MODE = 0,
};

#define ptp_caps_to_data(d) \
		container_of((d), struct sja1105_ptp_data, caps)
#define ptp_data_to_sja1105(d) \
		container_of((d), struct sja1105_private, ptp_data)

static int sja1105_init_avb_params(struct sja1105_private *priv,
				   bool on)
{
	struct sja1105_avb_params_entry *avb;
	struct sja1105_table *table;

	table = &priv->static_config.tables[BLK_IDX_AVB_PARAMS];

	/* Discard previous AVB Parameters Table */
	if (table->entry_count) {
		kfree(table->entries);
		table->entry_count = 0;
	}

	/* Configure the reception of meta frames only if requested */
	if (!on)
		return 0;

	table->entries = kcalloc(SJA1105_MAX_AVB_PARAMS_COUNT,
				 table->ops->unpacked_entry_size, GFP_KERNEL);
	if (!table->entries)
		return -ENOMEM;

	table->entry_count = SJA1105_MAX_AVB_PARAMS_COUNT;

	avb = table->entries;

	avb->destmeta = SJA1105_META_DMAC;
	avb->srcmeta  = SJA1105_META_SMAC;

	return 0;
}

/* Must be called only with priv->tagger_data.state bit
 * SJA1105_HWTS_RX_EN cleared
 */
static int sja1105_change_rxtstamping(struct sja1105_private *priv,
				      bool on)
{
	struct sja1105_general_params_entry *general_params;
	struct sja1105_table *table;
	int rc;

	table = &priv->static_config.tables[BLK_IDX_GENERAL_PARAMS];
	general_params = table->entries;
	general_params->send_meta1 = on;
	general_params->send_meta0 = on;

	rc = sja1105_init_avb_params(priv, on);
	if (rc < 0)
		return rc;

	/* Initialize the meta state machine to a known state */
	if (priv->tagger_data.stampable_skb) {
		kfree_skb(priv->tagger_data.stampable_skb);
		priv->tagger_data.stampable_skb = NULL;
	}

	return sja1105_static_config_reload(priv);
}

int sja1105_hwtstamp_set(struct dsa_switch *ds, int port, struct ifreq *ifr)
{
	struct sja1105_private *priv = ds->priv;
	struct hwtstamp_config config;
	bool rx_on;
	int rc;

	if (copy_from_user(&config, ifr->ifr_data, sizeof(config)))
		return -EFAULT;

	switch (config.tx_type) {
	case HWTSTAMP_TX_OFF:
		priv->ports[port].hwts_tx_en = false;
		break;
	case HWTSTAMP_TX_ON:
		priv->ports[port].hwts_tx_en = true;
		break;
	default:
		return -ERANGE;
	}

	switch (config.rx_filter) {
	case HWTSTAMP_FILTER_NONE:
		rx_on = false;
		break;
	default:
		rx_on = true;
		break;
	}

	if (rx_on != test_bit(SJA1105_HWTS_RX_EN, &priv->tagger_data.state)) {
		clear_bit(SJA1105_HWTS_RX_EN, &priv->tagger_data.state);

		rc = sja1105_change_rxtstamping(priv, rx_on);
		if (rc < 0) {
			dev_err(ds->dev,
				"Failed to change RX timestamping: %d\n", rc);
			return rc;
		}
		if (rx_on)
			set_bit(SJA1105_HWTS_RX_EN, &priv->tagger_data.state);
	}

	if (copy_to_user(ifr->ifr_data, &config, sizeof(config)))
		return -EFAULT;
	return 0;
}

int sja1105_hwtstamp_get(struct dsa_switch *ds, int port, struct ifreq *ifr)
{
	struct sja1105_private *priv = ds->priv;
	struct hwtstamp_config config;

	config.flags = 0;
	if (priv->ports[port].hwts_tx_en)
		config.tx_type = HWTSTAMP_TX_ON;
	else
		config.tx_type = HWTSTAMP_TX_OFF;
	if (test_bit(SJA1105_HWTS_RX_EN, &priv->tagger_data.state))
		config.rx_filter = HWTSTAMP_FILTER_PTP_V2_L2_EVENT;
	else
		config.rx_filter = HWTSTAMP_FILTER_NONE;

	return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
		-EFAULT : 0;
}

int sja1105_get_ts_info(struct dsa_switch *ds, int port,
			struct ethtool_ts_info *info)
{
	struct sja1105_private *priv = ds->priv;
	struct sja1105_ptp_data *ptp_data = &priv->ptp_data;

	/* Called during cleanup */
	if (!ptp_data->clock)
		return -ENODEV;

	info->so_timestamping = SOF_TIMESTAMPING_TX_HARDWARE |
				SOF_TIMESTAMPING_RX_HARDWARE |
				SOF_TIMESTAMPING_RAW_HARDWARE;
	info->tx_types = (1 << HWTSTAMP_TX_OFF) |
			 (1 << HWTSTAMP_TX_ON);
	info->rx_filters = (1 << HWTSTAMP_FILTER_NONE) |
			   (1 << HWTSTAMP_FILTER_PTP_V2_L2_EVENT);
	info->phc_index = ptp_clock_index(ptp_data->clock);
	return 0;
}

int sja1105et_ptp_cmd(const struct dsa_switch *ds,
		      const struct sja1105_ptp_cmd *cmd)
{
	const struct sja1105_private *priv = ds->priv;
	const struct sja1105_regs *regs = priv->info->regs;
	const int size = SJA1105_SIZE_PTP_CMD;
	u8 buf[SJA1105_SIZE_PTP_CMD] = {0};
	/* No need to keep this as part of the structure */
	u64 valid = 1;

	sja1105_pack(buf, &valid,           31, 31, size);
	sja1105_pack(buf, &cmd->resptp,      2,  2, size);
	sja1105_pack(buf, &cmd->corrclk4ts,  1,  1, size);
	sja1105_pack(buf, &cmd->ptpclkadd,   0,  0, size);

	return sja1105_xfer_buf(priv, SPI_WRITE, regs->ptp_control, buf,
				SJA1105_SIZE_PTP_CMD);
}

int sja1105pqrs_ptp_cmd(const struct dsa_switch *ds,
			const struct sja1105_ptp_cmd *cmd)
{
	const struct sja1105_private *priv = ds->priv;
	const struct sja1105_regs *regs = priv->info->regs;
	const int size = SJA1105_SIZE_PTP_CMD;
	u8 buf[SJA1105_SIZE_PTP_CMD] = {0};
	/* No need to keep this as part of the structure */
	u64 valid = 1;

	sja1105_pack(buf, &valid,           31, 31, size);
	sja1105_pack(buf, &cmd->resptp,      3,  3, size);
	sja1105_pack(buf, &cmd->corrclk4ts,  2,  2, size);
	sja1105_pack(buf, &cmd->ptpclkadd,   0,  0, size);

	return sja1105_xfer_buf(priv, SPI_WRITE, regs->ptp_control, buf,
				SJA1105_SIZE_PTP_CMD);
}

/* The switch returns partial timestamps (24 bits for SJA1105 E/T, which wrap
 * around in 0.135 seconds, and 32 bits for P/Q/R/S, wrapping around in 34.35
 * seconds).
 *
 * This receives the RX or TX MAC timestamps, provided by hardware as
 * the lower bits of the cycle counter, sampled at the time the timestamp was
 * collected.
 *
 * To reconstruct into a full 64-bit-wide timestamp, the cycle counter is
 * read and the high-order bits are filled in.
 *
 * Must be called within one wraparound period of the partial timestamp since
 * it was generated by the MAC.
 */
static u64 sja1105_tstamp_reconstruct(struct dsa_switch *ds, u64 now,
				      u64 ts_partial)
{
	struct sja1105_private *priv = ds->priv;
	u64 partial_tstamp_mask = CYCLECOUNTER_MASK(priv->info->ptp_ts_bits);
	u64 ts_reconstructed;

	ts_reconstructed = (now & ~partial_tstamp_mask) | ts_partial;

	/* Check lower bits of current cycle counter against the timestamp.
	 * If the current cycle counter is lower than the partial timestamp,
	 * then wraparound surely occurred and must be accounted for.
	 */
	if ((now & partial_tstamp_mask) <= ts_partial)
		ts_reconstructed -= (partial_tstamp_mask + 1);

	return ts_reconstructed;
}

/* Reads the SPI interface for an egress timestamp generated by the switch
 * for frames sent using management routes.
 *
 * SJA1105 E/T layout of the 4-byte SPI payload:
 *
 * 31    23    15    7     0
 * |     |     |     |     |
 * +-----+-----+-----+     ^
 *          ^              |
 *          |              |
 *  24-bit timestamp   Update bit
 *
 *
 * SJA1105 P/Q/R/S layout of the 8-byte SPI payload:
 *
 * 31    23    15    7     0     63    55    47    39    32
 * |     |     |     |     |     |     |     |     |     |
 *                         ^     +-----+-----+-----+-----+
 *                         |                 ^
 *                         |                 |
 *                    Update bit    32-bit timestamp
 *
 * Notice that the update bit is in the same place.
 * To have common code for E/T and P/Q/R/S for reading the timestamp,
 * we need to juggle with the offset and the bit indices.
 */
static int sja1105_ptpegr_ts_poll(struct dsa_switch *ds, int port, u64 *ts)
{
	struct sja1105_private *priv = ds->priv;
	const struct sja1105_regs *regs = priv->info->regs;
	int tstamp_bit_start, tstamp_bit_end;
	int timeout = 10;
	u8 packed_buf[8];
	u64 update;
	int rc;

	do {
		rc = sja1105_xfer_buf(priv, SPI_READ, regs->ptpegr_ts[port],
				      packed_buf, priv->info->ptpegr_ts_bytes);
		if (rc < 0)
			return rc;

		sja1105_unpack(packed_buf, &update, 0, 0,
			       priv->info->ptpegr_ts_bytes);
		if (update)
			break;

		usleep_range(10, 50);
	} while (--timeout);

	if (!timeout)
		return -ETIMEDOUT;

	/* Point the end bit to the second 32-bit word on P/Q/R/S,
	 * no-op on E/T.
	 */
	tstamp_bit_end = (priv->info->ptpegr_ts_bytes - 4) * 8;
	/* Shift the 24-bit timestamp on E/T to be collected from 31:8.
	 * No-op on P/Q/R/S.
	 */
	tstamp_bit_end += 32 - priv->info->ptp_ts_bits;
	tstamp_bit_start = tstamp_bit_end + priv->info->ptp_ts_bits - 1;

	*ts = 0;

	sja1105_unpack(packed_buf, ts, tstamp_bit_start, tstamp_bit_end,
		       priv->info->ptpegr_ts_bytes);

	return 0;
}

/* Caller must hold ptp_data->lock */
static int sja1105_ptpclkval_read(struct sja1105_private *priv, u64 *ticks,
				  struct ptp_system_timestamp *ptp_sts)
{
	const struct sja1105_regs *regs = priv->info->regs;

	return sja1105_xfer_u64(priv, SPI_READ, regs->ptpclkval, ticks,
				ptp_sts);
}

/* Caller must hold ptp_data->lock */
static int sja1105_ptpclkval_write(struct sja1105_private *priv, u64 ticks)
{
	const struct sja1105_regs *regs = priv->info->regs;

	return sja1105_xfer_u64(priv, SPI_WRITE, regs->ptpclkval, &ticks,
				NULL);
}

#define rxtstamp_to_tagger(d) \
	container_of((d), struct sja1105_tagger_data, rxtstamp_work)
#define tagger_to_sja1105(d) \
	container_of((d), struct sja1105_private, tagger_data)

static void sja1105_rxtstamp_work(struct work_struct *work)
{
	struct sja1105_tagger_data *tagger_data = rxtstamp_to_tagger(work);
	struct sja1105_private *priv = tagger_to_sja1105(tagger_data);
	struct sja1105_ptp_data *ptp_data = &priv->ptp_data;
	struct dsa_switch *ds = priv->ds;
	struct sk_buff *skb;

	mutex_lock(&ptp_data->lock);

	while ((skb = skb_dequeue(&tagger_data->skb_rxtstamp_queue)) != NULL) {
		struct skb_shared_hwtstamps *shwt = skb_hwtstamps(skb);
		u64 ticks, ts;
		int rc;

		rc = sja1105_ptpclkval_read(priv, &ticks, NULL);
		if (rc < 0) {
			dev_err(ds->dev, "Failed to read PTP clock: %d\n", rc);
			kfree_skb(skb);
			continue;
		}

		*shwt = (struct skb_shared_hwtstamps) {0};

		ts = SJA1105_SKB_CB(skb)->meta_tstamp;
		ts = sja1105_tstamp_reconstruct(ds, ticks, ts);

		shwt->hwtstamp = ns_to_ktime(sja1105_ticks_to_ns(ts));
		netif_rx_ni(skb);
	}

	mutex_unlock(&ptp_data->lock);
}

/* Called from dsa_skb_defer_rx_timestamp */
bool sja1105_port_rxtstamp(struct dsa_switch *ds, int port,
			   struct sk_buff *skb, unsigned int type)
{
	struct sja1105_private *priv = ds->priv;
	struct sja1105_tagger_data *tagger_data = &priv->tagger_data;

	if (!test_bit(SJA1105_HWTS_RX_EN, &tagger_data->state))
		return false;

	/* We need to read the full PTP clock to reconstruct the Rx
	 * timestamp. For that we need a sleepable context.
	 */
	skb_queue_tail(&tagger_data->skb_rxtstamp_queue, skb);
	schedule_work(&tagger_data->rxtstamp_work);
	return true;
}

/* Called from dsa_skb_tx_timestamp. This callback is just to make DSA clone
 * the skb and have it available in DSA_SKB_CB in the .port_deferred_xmit
 * callback, where we will timestamp it synchronously.
 */
bool sja1105_port_txtstamp(struct dsa_switch *ds, int port,
			   struct sk_buff *skb, unsigned int type)
{
	struct sja1105_private *priv = ds->priv;
	struct sja1105_port *sp = &priv->ports[port];

	if (!sp->hwts_tx_en)
		return false;

	return true;
}

int sja1105_ptp_reset(struct dsa_switch *ds)
{
	struct sja1105_private *priv = ds->priv;
	struct sja1105_ptp_data *ptp_data = &priv->ptp_data;
	struct sja1105_ptp_cmd cmd = ptp_data->cmd;
	int rc;

	mutex_lock(&ptp_data->lock);

	cmd.resptp = 1;
	dev_dbg(ds->dev, "Resetting PTP clock\n");
	rc = priv->info->ptp_cmd(ds, &cmd);

	mutex_unlock(&ptp_data->lock);

	return rc;
}

static int sja1105_ptp_gettimex(struct ptp_clock_info *ptp,
				struct timespec64 *ts,
				struct ptp_system_timestamp *ptp_sts)
{
	struct sja1105_ptp_data *ptp_data = ptp_caps_to_data(ptp);
	struct sja1105_private *priv = ptp_data_to_sja1105(ptp_data);
	u64 ticks = 0;
	int rc;

	mutex_lock(&ptp_data->lock);

	rc = sja1105_ptpclkval_read(priv, &ticks, ptp_sts);
	*ts = ns_to_timespec64(sja1105_ticks_to_ns(ticks));

	mutex_unlock(&ptp_data->lock);

	return rc;
}

/* Caller must hold ptp_data->lock */
static int sja1105_ptp_mode_set(struct sja1105_private *priv,
				enum sja1105_ptp_clk_mode mode)
{
	struct sja1105_ptp_data *ptp_data = &priv->ptp_data;

	if (ptp_data->cmd.ptpclkadd == mode)
		return 0;

	ptp_data->cmd.ptpclkadd = mode;

	return priv->info->ptp_cmd(priv->ds, &ptp_data->cmd);
}

/* Write to PTPCLKVAL while PTPCLKADD is 0 */
static int sja1105_ptp_settime(struct ptp_clock_info *ptp,
			       const struct timespec64 *ts)
{
	struct sja1105_ptp_data *ptp_data = ptp_caps_to_data(ptp);
	struct sja1105_private *priv = ptp_data_to_sja1105(ptp_data);
	u64 ticks = ns_to_sja1105_ticks(timespec64_to_ns(ts));
	int rc;

	mutex_lock(&ptp_data->lock);

	rc = sja1105_ptp_mode_set(priv, PTP_SET_MODE);
	if (rc < 0) {
		dev_err(priv->ds->dev, "Failed to put PTPCLK in set mode\n");
		goto out;
	}

	rc = sja1105_ptpclkval_write(priv, ticks);
out:
	mutex_unlock(&ptp_data->lock);

	return rc;
}

static int sja1105_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
{
	struct sja1105_ptp_data *ptp_data = ptp_caps_to_data(ptp);
	struct sja1105_private *priv = ptp_data_to_sja1105(ptp_data);
	const struct sja1105_regs *regs = priv->info->regs;
	u32 clkrate32;
	s64 clkrate;
	int rc;

	clkrate = (s64)scaled_ppm * SJA1105_CC_MULT_NUM;
	clkrate = div_s64(clkrate, SJA1105_CC_MULT_DEM);

	/* Take a +/- value and re-center it around 2^31. */
	clkrate = SJA1105_CC_MULT + clkrate;
	WARN_ON(abs(clkrate) >= GENMASK_ULL(31, 0));
	clkrate32 = clkrate;

	mutex_lock(&ptp_data->lock);

	rc = sja1105_xfer_u32(priv, SPI_WRITE, regs->ptpclkrate, &clkrate32,
			      NULL);

	mutex_unlock(&ptp_data->lock);

	return rc;
}

/* Write to PTPCLKVAL while PTPCLKADD is 1 */
static int sja1105_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
{
	struct sja1105_ptp_data *ptp_data = ptp_caps_to_data(ptp);
	struct sja1105_private *priv = ptp_data_to_sja1105(ptp_data);
	s64 ticks = ns_to_sja1105_ticks(delta);
	int rc;

	mutex_lock(&ptp_data->lock);

	rc = sja1105_ptp_mode_set(priv, PTP_ADD_MODE);
	if (rc < 0) {
		dev_err(priv->ds->dev, "Failed to put PTPCLK in add mode\n");
		goto out;
	}

	rc = sja1105_ptpclkval_write(priv, ticks);

out:
	mutex_unlock(&ptp_data->lock);

	return rc;
}

int sja1105_ptp_clock_register(struct dsa_switch *ds)
{
	struct sja1105_private *priv = ds->priv;
	struct sja1105_tagger_data *tagger_data = &priv->tagger_data;
	struct sja1105_ptp_data *ptp_data = &priv->ptp_data;

	ptp_data->caps = (struct ptp_clock_info) {
		.owner		= THIS_MODULE,
		.name		= "SJA1105 PHC",
		.adjfine	= sja1105_ptp_adjfine,
		.adjtime	= sja1105_ptp_adjtime,
		.gettimex64	= sja1105_ptp_gettimex,
		.settime64	= sja1105_ptp_settime,
		.max_adj	= SJA1105_MAX_ADJ_PPB,
	};

	skb_queue_head_init(&tagger_data->skb_rxtstamp_queue);
	INIT_WORK(&tagger_data->rxtstamp_work, sja1105_rxtstamp_work);
	spin_lock_init(&tagger_data->meta_lock);

	ptp_data->clock = ptp_clock_register(&ptp_data->caps, ds->dev);
	if (IS_ERR_OR_NULL(ptp_data->clock))
		return PTR_ERR(ptp_data->clock);

	ptp_data->cmd.corrclk4ts = true;
	ptp_data->cmd.ptpclkadd = PTP_SET_MODE;

	return sja1105_ptp_reset(ds);
}

void sja1105_ptp_clock_unregister(struct dsa_switch *ds)
{
	struct sja1105_private *priv = ds->priv;
	struct sja1105_ptp_data *ptp_data = &priv->ptp_data;

	if (IS_ERR_OR_NULL(ptp_data->clock))
		return;

	cancel_work_sync(&priv->tagger_data.rxtstamp_work);
	skb_queue_purge(&priv->tagger_data.skb_rxtstamp_queue);
	ptp_clock_unregister(ptp_data->clock);
	ptp_data->clock = NULL;
}

void sja1105_ptp_txtstamp_skb(struct dsa_switch *ds, int slot,
			      struct sk_buff *skb)
{
	struct sja1105_private *priv = ds->priv;
	struct sja1105_ptp_data *ptp_data = &priv->ptp_data;
	struct skb_shared_hwtstamps shwt = {0};
	u64 ticks, ts;
	int rc;

	skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;

	mutex_lock(&ptp_data->lock);

	rc = sja1105_ptpclkval_read(priv, &ticks, NULL);
	if (rc < 0) {
		dev_err(ds->dev, "Failed to read PTP clock: %d\n", rc);
		kfree_skb(skb);
		goto out;
	}

	rc = sja1105_ptpegr_ts_poll(ds, slot, &ts);
	if (rc < 0) {
		dev_err(ds->dev, "timed out polling for tstamp\n");
		kfree_skb(skb);
		goto out;
	}

	ts = sja1105_tstamp_reconstruct(ds, ticks, ts);

	shwt.hwtstamp = ns_to_ktime(sja1105_ticks_to_ns(ts));
	skb_complete_tx_timestamp(skb, &shwt);

out:
	mutex_unlock(&ptp_data->lock);
}