xref: /openbmc/linux/drivers/ptp/ptp_ines.c (revision 505b0877)
1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // Copyright (C) 2018 MOSER-BAER AG
4 //
5 
6 #define pr_fmt(fmt) "InES_PTP: " fmt
7 
8 #include <linux/ethtool.h>
9 #include <linux/export.h>
10 #include <linux/if_vlan.h>
11 #include <linux/mii_timestamper.h>
12 #include <linux/module.h>
13 #include <linux/net_tstamp.h>
14 #include <linux/of.h>
15 #include <linux/of_address.h>
16 #include <linux/of_irq.h>
17 #include <linux/phy.h>
18 #include <linux/platform_device.h>
19 #include <linux/ptp_classify.h>
20 #include <linux/ptp_clock_kernel.h>
21 #include <linux/stddef.h>
22 
23 MODULE_DESCRIPTION("Driver for the ZHAW InES PTP time stamping IP core");
24 MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
25 MODULE_VERSION("1.0");
26 MODULE_LICENSE("GPL");
27 
28 /* GLOBAL register */
29 #define MCAST_MAC_SELECT_SHIFT	2
30 #define MCAST_MAC_SELECT_MASK	0x3
31 #define IO_RESET		BIT(1)
32 #define PTP_RESET		BIT(0)
33 
34 /* VERSION register */
35 #define IF_MAJOR_VER_SHIFT	12
36 #define IF_MAJOR_VER_MASK	0xf
37 #define IF_MINOR_VER_SHIFT	8
38 #define IF_MINOR_VER_MASK	0xf
39 #define FPGA_MAJOR_VER_SHIFT	4
40 #define FPGA_MAJOR_VER_MASK	0xf
41 #define FPGA_MINOR_VER_SHIFT	0
42 #define FPGA_MINOR_VER_MASK	0xf
43 
44 /* INT_STAT register */
45 #define RX_INTR_STATUS_3	BIT(5)
46 #define RX_INTR_STATUS_2	BIT(4)
47 #define RX_INTR_STATUS_1	BIT(3)
48 #define TX_INTR_STATUS_3	BIT(2)
49 #define TX_INTR_STATUS_2	BIT(1)
50 #define TX_INTR_STATUS_1	BIT(0)
51 
52 /* INT_MSK register */
53 #define RX_INTR_MASK_3		BIT(5)
54 #define RX_INTR_MASK_2		BIT(4)
55 #define RX_INTR_MASK_1		BIT(3)
56 #define TX_INTR_MASK_3		BIT(2)
57 #define TX_INTR_MASK_2		BIT(1)
58 #define TX_INTR_MASK_1		BIT(0)
59 
60 /* BUF_STAT register */
61 #define RX_FIFO_NE_3		BIT(5)
62 #define RX_FIFO_NE_2		BIT(4)
63 #define RX_FIFO_NE_1		BIT(3)
64 #define TX_FIFO_NE_3		BIT(2)
65 #define TX_FIFO_NE_2		BIT(1)
66 #define TX_FIFO_NE_1		BIT(0)
67 
68 /* PORT_CONF register */
69 #define CM_ONE_STEP		BIT(6)
70 #define PHY_SPEED_SHIFT		4
71 #define PHY_SPEED_MASK		0x3
72 #define P2P_DELAY_WR_POS_SHIFT	2
73 #define P2P_DELAY_WR_POS_MASK	0x3
74 #define PTP_MODE_SHIFT		0
75 #define PTP_MODE_MASK		0x3
76 
77 /* TS_STAT_TX register */
78 #define TS_ENABLE		BIT(15)
79 #define DATA_READ_POS_SHIFT	8
80 #define DATA_READ_POS_MASK	0x1f
81 #define DISCARDED_EVENTS_SHIFT	4
82 #define DISCARDED_EVENTS_MASK	0xf
83 
84 #define INES_N_PORTS		3
85 #define INES_REGISTER_SIZE	0x80
86 #define INES_PORT_OFFSET	0x20
87 #define INES_PORT_SIZE		0x20
88 #define INES_FIFO_DEPTH		90
89 #define INES_MAX_EVENTS		100
90 
91 #define BC_PTP_V1		0
92 #define BC_PTP_V2		1
93 #define TC_E2E_PTP_V2		2
94 #define TC_P2P_PTP_V2		3
95 
96 #define PHY_SPEED_10		0
97 #define PHY_SPEED_100		1
98 #define PHY_SPEED_1000		2
99 
100 #define PORT_CONF \
101 	((PHY_SPEED_1000 << PHY_SPEED_SHIFT) | (BC_PTP_V2 << PTP_MODE_SHIFT))
102 
103 #define ines_read32(s, r)	__raw_readl((void __iomem *)&s->regs->r)
104 #define ines_write32(s, v, r)	__raw_writel(v, (void __iomem *)&s->regs->r)
105 
106 #define MESSAGE_TYPE_SYNC		1
107 #define MESSAGE_TYPE_P_DELAY_REQ	2
108 #define MESSAGE_TYPE_P_DELAY_RESP	3
109 #define MESSAGE_TYPE_DELAY_REQ		4
110 
111 #define SYNC				0x0
112 #define DELAY_REQ			0x1
113 #define PDELAY_REQ			0x2
114 #define PDELAY_RESP			0x3
115 
116 static LIST_HEAD(ines_clocks);
117 static DEFINE_MUTEX(ines_clocks_lock);
118 
119 struct ines_global_regs {
120 	u32 id;
121 	u32 test;
122 	u32 global;
123 	u32 version;
124 	u32 test2;
125 	u32 int_stat;
126 	u32 int_msk;
127 	u32 buf_stat;
128 };
129 
130 struct ines_port_registers {
131 	u32 port_conf;
132 	u32 p_delay;
133 	u32 ts_stat_tx;
134 	u32 ts_stat_rx;
135 	u32 ts_tx;
136 	u32 ts_rx;
137 };
138 
139 struct ines_timestamp {
140 	struct list_head list;
141 	unsigned long	tmo;
142 	u16		tag;
143 	u64		sec;
144 	u64		nsec;
145 	u64		clkid;
146 	u16		portnum;
147 	u16		seqid;
148 };
149 
150 struct ines_port {
151 	struct ines_port_registers	*regs;
152 	struct mii_timestamper		mii_ts;
153 	struct ines_clock		*clock;
154 	bool				rxts_enabled;
155 	bool				txts_enabled;
156 	unsigned int			index;
157 	struct delayed_work		ts_work;
158 	/* lock protects event list and tx_skb */
159 	spinlock_t			lock;
160 	struct sk_buff			*tx_skb;
161 	struct list_head		events;
162 	struct list_head		pool;
163 	struct ines_timestamp		pool_data[INES_MAX_EVENTS];
164 };
165 
166 struct ines_clock {
167 	struct ines_port		port[INES_N_PORTS];
168 	struct ines_global_regs __iomem	*regs;
169 	void __iomem			*base;
170 	struct device_node		*node;
171 	struct device			*dev;
172 	struct list_head		list;
173 };
174 
175 static bool ines_match(struct sk_buff *skb, unsigned int ptp_class,
176 		       struct ines_timestamp *ts, struct device *dev);
177 static int ines_rxfifo_read(struct ines_port *port);
178 static u64 ines_rxts64(struct ines_port *port, unsigned int words);
179 static bool ines_timestamp_expired(struct ines_timestamp *ts);
180 static u64 ines_txts64(struct ines_port *port, unsigned int words);
181 static void ines_txtstamp_work(struct work_struct *work);
182 static bool is_sync_pdelay_resp(struct sk_buff *skb, int type);
183 static u8 tag_to_msgtype(u8 tag);
184 
185 static void ines_clock_cleanup(struct ines_clock *clock)
186 {
187 	struct ines_port *port;
188 	int i;
189 
190 	for (i = 0; i < INES_N_PORTS; i++) {
191 		port = &clock->port[i];
192 		cancel_delayed_work_sync(&port->ts_work);
193 	}
194 }
195 
196 static int ines_clock_init(struct ines_clock *clock, struct device *device,
197 			   void __iomem *addr)
198 {
199 	struct device_node *node = device->of_node;
200 	unsigned long port_addr;
201 	struct ines_port *port;
202 	int i, j;
203 
204 	INIT_LIST_HEAD(&clock->list);
205 	clock->node = node;
206 	clock->dev  = device;
207 	clock->base = addr;
208 	clock->regs = clock->base;
209 
210 	for (i = 0; i < INES_N_PORTS; i++) {
211 		port = &clock->port[i];
212 		port_addr = (unsigned long) clock->base +
213 			INES_PORT_OFFSET + i * INES_PORT_SIZE;
214 		port->regs = (struct ines_port_registers *) port_addr;
215 		port->clock = clock;
216 		port->index = i;
217 		INIT_DELAYED_WORK(&port->ts_work, ines_txtstamp_work);
218 		spin_lock_init(&port->lock);
219 		INIT_LIST_HEAD(&port->events);
220 		INIT_LIST_HEAD(&port->pool);
221 		for (j = 0; j < INES_MAX_EVENTS; j++)
222 			list_add(&port->pool_data[j].list, &port->pool);
223 	}
224 
225 	ines_write32(clock, 0xBEEF, test);
226 	ines_write32(clock, 0xBEEF, test2);
227 
228 	dev_dbg(device, "ID      0x%x\n", ines_read32(clock, id));
229 	dev_dbg(device, "TEST    0x%x\n", ines_read32(clock, test));
230 	dev_dbg(device, "VERSION 0x%x\n", ines_read32(clock, version));
231 	dev_dbg(device, "TEST2   0x%x\n", ines_read32(clock, test2));
232 
233 	for (i = 0; i < INES_N_PORTS; i++) {
234 		port = &clock->port[i];
235 		ines_write32(port, PORT_CONF, port_conf);
236 	}
237 
238 	return 0;
239 }
240 
241 static struct ines_port *ines_find_port(struct device_node *node, u32 index)
242 {
243 	struct ines_port *port = NULL;
244 	struct ines_clock *clock;
245 	struct list_head *this;
246 
247 	mutex_lock(&ines_clocks_lock);
248 	list_for_each(this, &ines_clocks) {
249 		clock = list_entry(this, struct ines_clock, list);
250 		if (clock->node == node) {
251 			port = &clock->port[index];
252 			break;
253 		}
254 	}
255 	mutex_unlock(&ines_clocks_lock);
256 	return port;
257 }
258 
259 static u64 ines_find_rxts(struct ines_port *port, struct sk_buff *skb, int type)
260 {
261 	struct list_head *this, *next;
262 	struct ines_timestamp *ts;
263 	unsigned long flags;
264 	u64 ns = 0;
265 
266 	if (type == PTP_CLASS_NONE)
267 		return 0;
268 
269 	spin_lock_irqsave(&port->lock, flags);
270 	ines_rxfifo_read(port);
271 	list_for_each_safe(this, next, &port->events) {
272 		ts = list_entry(this, struct ines_timestamp, list);
273 		if (ines_timestamp_expired(ts)) {
274 			list_del_init(&ts->list);
275 			list_add(&ts->list, &port->pool);
276 			continue;
277 		}
278 		if (ines_match(skb, type, ts, port->clock->dev)) {
279 			ns = ts->sec * 1000000000ULL + ts->nsec;
280 			list_del_init(&ts->list);
281 			list_add(&ts->list, &port->pool);
282 			break;
283 		}
284 	}
285 	spin_unlock_irqrestore(&port->lock, flags);
286 
287 	return ns;
288 }
289 
290 static u64 ines_find_txts(struct ines_port *port, struct sk_buff *skb)
291 {
292 	unsigned int class = ptp_classify_raw(skb), i;
293 	u32 data_rd_pos, buf_stat, mask, ts_stat_tx;
294 	struct ines_timestamp ts;
295 	unsigned long flags;
296 	u64 ns = 0;
297 
298 	mask = TX_FIFO_NE_1 << port->index;
299 
300 	spin_lock_irqsave(&port->lock, flags);
301 
302 	for (i = 0; i < INES_FIFO_DEPTH; i++) {
303 
304 		buf_stat = ines_read32(port->clock, buf_stat);
305 		if (!(buf_stat & mask)) {
306 			dev_dbg(port->clock->dev,
307 				  "Tx timestamp FIFO unexpectedly empty\n");
308 			break;
309 		}
310 		ts_stat_tx = ines_read32(port, ts_stat_tx);
311 		data_rd_pos = (ts_stat_tx >> DATA_READ_POS_SHIFT) &
312 			DATA_READ_POS_MASK;
313 		if (data_rd_pos) {
314 			dev_err(port->clock->dev,
315 				"unexpected Tx read pos %u\n", data_rd_pos);
316 			break;
317 		}
318 
319 		ts.tag     = ines_read32(port, ts_tx);
320 		ts.sec     = ines_txts64(port, 3);
321 		ts.nsec    = ines_txts64(port, 2);
322 		ts.clkid   = ines_txts64(port, 4);
323 		ts.portnum = ines_read32(port, ts_tx);
324 		ts.seqid   = ines_read32(port, ts_tx);
325 
326 		if (ines_match(skb, class, &ts, port->clock->dev)) {
327 			ns = ts.sec * 1000000000ULL + ts.nsec;
328 			break;
329 		}
330 	}
331 
332 	spin_unlock_irqrestore(&port->lock, flags);
333 	return ns;
334 }
335 
336 static int ines_hwtstamp(struct mii_timestamper *mii_ts, struct ifreq *ifr)
337 {
338 	struct ines_port *port = container_of(mii_ts, struct ines_port, mii_ts);
339 	u32 cm_one_step = 0, port_conf, ts_stat_rx, ts_stat_tx;
340 	struct hwtstamp_config cfg;
341 	unsigned long flags;
342 
343 	if (copy_from_user(&cfg, ifr->ifr_data, sizeof(cfg)))
344 		return -EFAULT;
345 
346 	/* reserved for future extensions */
347 	if (cfg.flags)
348 		return -EINVAL;
349 
350 	switch (cfg.tx_type) {
351 	case HWTSTAMP_TX_OFF:
352 		ts_stat_tx = 0;
353 		break;
354 	case HWTSTAMP_TX_ON:
355 		ts_stat_tx = TS_ENABLE;
356 		break;
357 	case HWTSTAMP_TX_ONESTEP_P2P:
358 		ts_stat_tx = TS_ENABLE;
359 		cm_one_step = CM_ONE_STEP;
360 		break;
361 	default:
362 		return -ERANGE;
363 	}
364 
365 	switch (cfg.rx_filter) {
366 	case HWTSTAMP_FILTER_NONE:
367 		ts_stat_rx = 0;
368 		break;
369 	case HWTSTAMP_FILTER_ALL:
370 	case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
371 	case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
372 	case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
373 		return -ERANGE;
374 	case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
375 	case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
376 	case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
377 	case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
378 	case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
379 	case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
380 	case HWTSTAMP_FILTER_PTP_V2_EVENT:
381 	case HWTSTAMP_FILTER_PTP_V2_SYNC:
382 	case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
383 		ts_stat_rx = TS_ENABLE;
384 		cfg.rx_filter = HWTSTAMP_FILTER_PTP_V2_EVENT;
385 		break;
386 	default:
387 		return -ERANGE;
388 	}
389 
390 	spin_lock_irqsave(&port->lock, flags);
391 
392 	port_conf = ines_read32(port, port_conf);
393 	port_conf &= ~CM_ONE_STEP;
394 	port_conf |= cm_one_step;
395 
396 	ines_write32(port, port_conf, port_conf);
397 	ines_write32(port, ts_stat_rx, ts_stat_rx);
398 	ines_write32(port, ts_stat_tx, ts_stat_tx);
399 
400 	port->rxts_enabled = ts_stat_rx == TS_ENABLE;
401 	port->txts_enabled = ts_stat_tx == TS_ENABLE;
402 
403 	spin_unlock_irqrestore(&port->lock, flags);
404 
405 	return copy_to_user(ifr->ifr_data, &cfg, sizeof(cfg)) ? -EFAULT : 0;
406 }
407 
408 static void ines_link_state(struct mii_timestamper *mii_ts,
409 			    struct phy_device *phydev)
410 {
411 	struct ines_port *port = container_of(mii_ts, struct ines_port, mii_ts);
412 	u32 port_conf, speed_conf;
413 	unsigned long flags;
414 
415 	switch (phydev->speed) {
416 	case SPEED_10:
417 		speed_conf = PHY_SPEED_10 << PHY_SPEED_SHIFT;
418 		break;
419 	case SPEED_100:
420 		speed_conf = PHY_SPEED_100 << PHY_SPEED_SHIFT;
421 		break;
422 	case SPEED_1000:
423 		speed_conf = PHY_SPEED_1000 << PHY_SPEED_SHIFT;
424 		break;
425 	default:
426 		dev_err(port->clock->dev, "bad speed: %d\n", phydev->speed);
427 		return;
428 	}
429 	spin_lock_irqsave(&port->lock, flags);
430 
431 	port_conf = ines_read32(port, port_conf);
432 	port_conf &= ~(0x3 << PHY_SPEED_SHIFT);
433 	port_conf |= speed_conf;
434 
435 	ines_write32(port, port_conf, port_conf);
436 
437 	spin_unlock_irqrestore(&port->lock, flags);
438 }
439 
440 static bool ines_match(struct sk_buff *skb, unsigned int ptp_class,
441 		       struct ines_timestamp *ts, struct device *dev)
442 {
443 	struct ptp_header *hdr;
444 	u16 portn, seqid;
445 	u8 msgtype;
446 	u64 clkid;
447 
448 	if (unlikely(ptp_class & PTP_CLASS_V1))
449 		return false;
450 
451 	hdr = ptp_parse_header(skb, ptp_class);
452 	if (!hdr)
453 		return false;
454 
455 	msgtype = ptp_get_msgtype(hdr, ptp_class);
456 	clkid = be64_to_cpup((__be64 *)&hdr->source_port_identity.clock_identity.id[0]);
457 	portn = be16_to_cpu(hdr->source_port_identity.port_number);
458 	seqid = be16_to_cpu(hdr->sequence_id);
459 
460 	if (tag_to_msgtype(ts->tag & 0x7) != msgtype) {
461 		dev_dbg(dev, "msgtype mismatch ts %hhu != skb %hhu\n",
462 			tag_to_msgtype(ts->tag & 0x7), msgtype);
463 		return false;
464 	}
465 	if (ts->clkid != clkid) {
466 		dev_dbg(dev, "clkid mismatch ts %llx != skb %llx\n",
467 			ts->clkid, clkid);
468 		return false;
469 	}
470 	if (ts->portnum != portn) {
471 		dev_dbg(dev, "portn mismatch ts %hu != skb %hu\n",
472 			ts->portnum, portn);
473 		return false;
474 	}
475 	if (ts->seqid != seqid) {
476 		dev_dbg(dev, "seqid mismatch ts %hu != skb %hu\n",
477 			ts->seqid, seqid);
478 		return false;
479 	}
480 
481 	return true;
482 }
483 
484 static bool ines_rxtstamp(struct mii_timestamper *mii_ts,
485 			  struct sk_buff *skb, int type)
486 {
487 	struct ines_port *port = container_of(mii_ts, struct ines_port, mii_ts);
488 	struct skb_shared_hwtstamps *ssh;
489 	u64 ns;
490 
491 	if (!port->rxts_enabled)
492 		return false;
493 
494 	ns = ines_find_rxts(port, skb, type);
495 	if (!ns)
496 		return false;
497 
498 	ssh = skb_hwtstamps(skb);
499 	ssh->hwtstamp = ns_to_ktime(ns);
500 	netif_rx(skb);
501 
502 	return true;
503 }
504 
505 static int ines_rxfifo_read(struct ines_port *port)
506 {
507 	u32 data_rd_pos, buf_stat, mask, ts_stat_rx;
508 	struct ines_timestamp *ts;
509 	unsigned int i;
510 
511 	mask = RX_FIFO_NE_1 << port->index;
512 
513 	for (i = 0; i < INES_FIFO_DEPTH; i++) {
514 		if (list_empty(&port->pool)) {
515 			dev_err(port->clock->dev, "event pool is empty\n");
516 			return -1;
517 		}
518 		buf_stat = ines_read32(port->clock, buf_stat);
519 		if (!(buf_stat & mask))
520 			break;
521 
522 		ts_stat_rx = ines_read32(port, ts_stat_rx);
523 		data_rd_pos = (ts_stat_rx >> DATA_READ_POS_SHIFT) &
524 			DATA_READ_POS_MASK;
525 		if (data_rd_pos) {
526 			dev_err(port->clock->dev, "unexpected Rx read pos %u\n",
527 				data_rd_pos);
528 			break;
529 		}
530 
531 		ts = list_first_entry(&port->pool, struct ines_timestamp, list);
532 		ts->tmo     = jiffies + HZ;
533 		ts->tag     = ines_read32(port, ts_rx);
534 		ts->sec     = ines_rxts64(port, 3);
535 		ts->nsec    = ines_rxts64(port, 2);
536 		ts->clkid   = ines_rxts64(port, 4);
537 		ts->portnum = ines_read32(port, ts_rx);
538 		ts->seqid   = ines_read32(port, ts_rx);
539 
540 		list_del_init(&ts->list);
541 		list_add_tail(&ts->list, &port->events);
542 	}
543 
544 	return 0;
545 }
546 
547 static u64 ines_rxts64(struct ines_port *port, unsigned int words)
548 {
549 	unsigned int i;
550 	u64 result;
551 	u16 word;
552 
553 	word = ines_read32(port, ts_rx);
554 	result = word;
555 	words--;
556 	for (i = 0; i < words; i++) {
557 		word = ines_read32(port, ts_rx);
558 		result <<= 16;
559 		result |= word;
560 	}
561 	return result;
562 }
563 
564 static bool ines_timestamp_expired(struct ines_timestamp *ts)
565 {
566 	return time_after(jiffies, ts->tmo);
567 }
568 
569 static int ines_ts_info(struct mii_timestamper *mii_ts,
570 			struct ethtool_ts_info *info)
571 {
572 	info->so_timestamping =
573 		SOF_TIMESTAMPING_TX_HARDWARE |
574 		SOF_TIMESTAMPING_TX_SOFTWARE |
575 		SOF_TIMESTAMPING_RX_HARDWARE |
576 		SOF_TIMESTAMPING_RX_SOFTWARE |
577 		SOF_TIMESTAMPING_SOFTWARE |
578 		SOF_TIMESTAMPING_RAW_HARDWARE;
579 
580 	info->phc_index = -1;
581 
582 	info->tx_types =
583 		(1 << HWTSTAMP_TX_OFF) |
584 		(1 << HWTSTAMP_TX_ON) |
585 		(1 << HWTSTAMP_TX_ONESTEP_P2P);
586 
587 	info->rx_filters =
588 		(1 << HWTSTAMP_FILTER_NONE) |
589 		(1 << HWTSTAMP_FILTER_PTP_V2_EVENT);
590 
591 	return 0;
592 }
593 
594 static u64 ines_txts64(struct ines_port *port, unsigned int words)
595 {
596 	unsigned int i;
597 	u64 result;
598 	u16 word;
599 
600 	word = ines_read32(port, ts_tx);
601 	result = word;
602 	words--;
603 	for (i = 0; i < words; i++) {
604 		word = ines_read32(port, ts_tx);
605 		result <<= 16;
606 		result |= word;
607 	}
608 	return result;
609 }
610 
611 static bool ines_txts_onestep(struct ines_port *port, struct sk_buff *skb, int type)
612 {
613 	unsigned long flags;
614 	u32 port_conf;
615 
616 	spin_lock_irqsave(&port->lock, flags);
617 	port_conf = ines_read32(port, port_conf);
618 	spin_unlock_irqrestore(&port->lock, flags);
619 
620 	if (port_conf & CM_ONE_STEP)
621 		return is_sync_pdelay_resp(skb, type);
622 
623 	return false;
624 }
625 
626 static void ines_txtstamp(struct mii_timestamper *mii_ts,
627 			  struct sk_buff *skb, int type)
628 {
629 	struct ines_port *port = container_of(mii_ts, struct ines_port, mii_ts);
630 	struct sk_buff *old_skb = NULL;
631 	unsigned long flags;
632 
633 	if (!port->txts_enabled || ines_txts_onestep(port, skb, type)) {
634 		kfree_skb(skb);
635 		return;
636 	}
637 
638 	spin_lock_irqsave(&port->lock, flags);
639 
640 	if (port->tx_skb)
641 		old_skb = port->tx_skb;
642 
643 	port->tx_skb = skb;
644 
645 	spin_unlock_irqrestore(&port->lock, flags);
646 
647 	kfree_skb(old_skb);
648 
649 	schedule_delayed_work(&port->ts_work, 1);
650 }
651 
652 static void ines_txtstamp_work(struct work_struct *work)
653 {
654 	struct ines_port *port =
655 		container_of(work, struct ines_port, ts_work.work);
656 	struct skb_shared_hwtstamps ssh;
657 	struct sk_buff *skb;
658 	unsigned long flags;
659 	u64 ns;
660 
661 	spin_lock_irqsave(&port->lock, flags);
662 	skb = port->tx_skb;
663 	port->tx_skb = NULL;
664 	spin_unlock_irqrestore(&port->lock, flags);
665 
666 	ns = ines_find_txts(port, skb);
667 	if (!ns) {
668 		kfree_skb(skb);
669 		return;
670 	}
671 	ssh.hwtstamp = ns_to_ktime(ns);
672 	skb_complete_tx_timestamp(skb, &ssh);
673 }
674 
675 static bool is_sync_pdelay_resp(struct sk_buff *skb, int type)
676 {
677 	struct ptp_header *hdr;
678 	u8 msgtype;
679 
680 	hdr = ptp_parse_header(skb, type);
681 	if (!hdr)
682 		return false;
683 
684 	msgtype = ptp_get_msgtype(hdr, type);
685 
686 	switch ((msgtype & 0xf)) {
687 	case SYNC:
688 	case PDELAY_RESP:
689 		return true;
690 	default:
691 		return false;
692 	}
693 }
694 
695 static u8 tag_to_msgtype(u8 tag)
696 {
697 	switch (tag) {
698 	case MESSAGE_TYPE_SYNC:
699 		return SYNC;
700 	case MESSAGE_TYPE_P_DELAY_REQ:
701 		return PDELAY_REQ;
702 	case MESSAGE_TYPE_P_DELAY_RESP:
703 		return PDELAY_RESP;
704 	case MESSAGE_TYPE_DELAY_REQ:
705 		return DELAY_REQ;
706 	}
707 	return 0xf;
708 }
709 
710 static struct mii_timestamper *ines_ptp_probe_channel(struct device *device,
711 						      unsigned int index)
712 {
713 	struct device_node *node = device->of_node;
714 	struct ines_port *port;
715 
716 	if (index > INES_N_PORTS - 1) {
717 		dev_err(device, "bad port index %u\n", index);
718 		return ERR_PTR(-EINVAL);
719 	}
720 	port = ines_find_port(node, index);
721 	if (!port) {
722 		dev_err(device, "missing port index %u\n", index);
723 		return ERR_PTR(-ENODEV);
724 	}
725 	port->mii_ts.rxtstamp = ines_rxtstamp;
726 	port->mii_ts.txtstamp = ines_txtstamp;
727 	port->mii_ts.hwtstamp = ines_hwtstamp;
728 	port->mii_ts.link_state = ines_link_state;
729 	port->mii_ts.ts_info = ines_ts_info;
730 
731 	return &port->mii_ts;
732 }
733 
734 static void ines_ptp_release_channel(struct device *device,
735 				     struct mii_timestamper *mii_ts)
736 {
737 }
738 
739 static struct mii_timestamping_ctrl ines_ctrl = {
740 	.probe_channel = ines_ptp_probe_channel,
741 	.release_channel = ines_ptp_release_channel,
742 };
743 
744 static int ines_ptp_ctrl_probe(struct platform_device *pld)
745 {
746 	struct ines_clock *clock;
747 	void __iomem *addr;
748 	int err = 0;
749 
750 	addr = devm_platform_ioremap_resource(pld, 0);
751 	if (IS_ERR(addr)) {
752 		err = PTR_ERR(addr);
753 		goto out;
754 	}
755 	clock = kzalloc(sizeof(*clock), GFP_KERNEL);
756 	if (!clock) {
757 		err = -ENOMEM;
758 		goto out;
759 	}
760 	if (ines_clock_init(clock, &pld->dev, addr)) {
761 		kfree(clock);
762 		err = -ENOMEM;
763 		goto out;
764 	}
765 	err = register_mii_tstamp_controller(&pld->dev, &ines_ctrl);
766 	if (err) {
767 		kfree(clock);
768 		goto out;
769 	}
770 	mutex_lock(&ines_clocks_lock);
771 	list_add_tail(&ines_clocks, &clock->list);
772 	mutex_unlock(&ines_clocks_lock);
773 
774 	dev_set_drvdata(&pld->dev, clock);
775 out:
776 	return err;
777 }
778 
779 static int ines_ptp_ctrl_remove(struct platform_device *pld)
780 {
781 	struct ines_clock *clock = dev_get_drvdata(&pld->dev);
782 
783 	unregister_mii_tstamp_controller(&pld->dev);
784 	mutex_lock(&ines_clocks_lock);
785 	list_del(&clock->list);
786 	mutex_unlock(&ines_clocks_lock);
787 	ines_clock_cleanup(clock);
788 	kfree(clock);
789 	return 0;
790 }
791 
792 static const struct of_device_id ines_ptp_ctrl_of_match[] = {
793 	{ .compatible = "ines,ptp-ctrl" },
794 	{ }
795 };
796 
797 MODULE_DEVICE_TABLE(of, ines_ptp_ctrl_of_match);
798 
799 static struct platform_driver ines_ptp_ctrl_driver = {
800 	.probe  = ines_ptp_ctrl_probe,
801 	.remove = ines_ptp_ctrl_remove,
802 	.driver = {
803 		.name = "ines_ptp_ctrl",
804 		.of_match_table = of_match_ptr(ines_ptp_ctrl_of_match),
805 	},
806 };
807 module_platform_driver(ines_ptp_ctrl_driver);
808