xref: /linux/drivers/net/ethernet/freescale/fec_ptp.c (revision bfd5bb6f90af092aa345b15cd78143956a13c2a8)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Fast Ethernet Controller (ENET) PTP driver for MX6x.
4  *
5  * Copyright (C) 2012 Freescale Semiconductor, Inc.
6  */
7 
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9 
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/string.h>
13 #include <linux/ptrace.h>
14 #include <linux/errno.h>
15 #include <linux/ioport.h>
16 #include <linux/slab.h>
17 #include <linux/interrupt.h>
18 #include <linux/pci.h>
19 #include <linux/delay.h>
20 #include <linux/netdevice.h>
21 #include <linux/etherdevice.h>
22 #include <linux/skbuff.h>
23 #include <linux/spinlock.h>
24 #include <linux/workqueue.h>
25 #include <linux/bitops.h>
26 #include <linux/io.h>
27 #include <linux/irq.h>
28 #include <linux/clk.h>
29 #include <linux/platform_device.h>
30 #include <linux/phy.h>
31 #include <linux/fec.h>
32 #include <linux/of.h>
33 #include <linux/of_device.h>
34 #include <linux/of_gpio.h>
35 #include <linux/of_net.h>
36 
37 #include "fec.h"
38 
39 /* FEC 1588 register bits */
40 #define FEC_T_CTRL_SLAVE                0x00002000
41 #define FEC_T_CTRL_CAPTURE              0x00000800
42 #define FEC_T_CTRL_RESTART              0x00000200
43 #define FEC_T_CTRL_PERIOD_RST           0x00000030
44 #define FEC_T_CTRL_PERIOD_EN		0x00000010
45 #define FEC_T_CTRL_ENABLE               0x00000001
46 
47 #define FEC_T_INC_MASK                  0x0000007f
48 #define FEC_T_INC_OFFSET                0
49 #define FEC_T_INC_CORR_MASK             0x00007f00
50 #define FEC_T_INC_CORR_OFFSET           8
51 
52 #define FEC_T_CTRL_PINPER		0x00000080
53 #define FEC_T_TF0_MASK			0x00000001
54 #define FEC_T_TF0_OFFSET		0
55 #define FEC_T_TF1_MASK			0x00000002
56 #define FEC_T_TF1_OFFSET		1
57 #define FEC_T_TF2_MASK			0x00000004
58 #define FEC_T_TF2_OFFSET		2
59 #define FEC_T_TF3_MASK			0x00000008
60 #define FEC_T_TF3_OFFSET		3
61 #define FEC_T_TDRE_MASK			0x00000001
62 #define FEC_T_TDRE_OFFSET		0
63 #define FEC_T_TMODE_MASK		0x0000003C
64 #define FEC_T_TMODE_OFFSET		2
65 #define FEC_T_TIE_MASK			0x00000040
66 #define FEC_T_TIE_OFFSET		6
67 #define FEC_T_TF_MASK			0x00000080
68 #define FEC_T_TF_OFFSET			7
69 
70 #define FEC_ATIME_CTRL		0x400
71 #define FEC_ATIME		0x404
72 #define FEC_ATIME_EVT_OFFSET	0x408
73 #define FEC_ATIME_EVT_PERIOD	0x40c
74 #define FEC_ATIME_CORR		0x410
75 #define FEC_ATIME_INC		0x414
76 #define FEC_TS_TIMESTAMP	0x418
77 
78 #define FEC_TGSR		0x604
79 #define FEC_TCSR(n)		(0x608 + n * 0x08)
80 #define FEC_TCCR(n)		(0x60C + n * 0x08)
81 #define MAX_TIMER_CHANNEL	3
82 #define FEC_TMODE_TOGGLE	0x05
83 #define FEC_HIGH_PULSE		0x0F
84 
85 #define FEC_CC_MULT	(1 << 31)
86 #define FEC_COUNTER_PERIOD	(1 << 31)
87 #define PPS_OUPUT_RELOAD_PERIOD	NSEC_PER_SEC
88 #define FEC_CHANNLE_0		0
89 #define DEFAULT_PPS_CHANNEL	FEC_CHANNLE_0
90 
91 /**
92  * fec_ptp_enable_pps
93  * @fep: the fec_enet_private structure handle
94  * @enable: enable the channel pps output
95  *
96  * This function enble the PPS ouput on the timer channel.
97  */
98 static int fec_ptp_enable_pps(struct fec_enet_private *fep, uint enable)
99 {
100 	unsigned long flags;
101 	u32 val, tempval;
102 	int inc;
103 	struct timespec64 ts;
104 	u64 ns;
105 	val = 0;
106 
107 	if (!(fep->hwts_tx_en || fep->hwts_rx_en)) {
108 		dev_err(&fep->pdev->dev, "No ptp stack is running\n");
109 		return -EINVAL;
110 	}
111 
112 	if (fep->pps_enable == enable)
113 		return 0;
114 
115 	fep->pps_channel = DEFAULT_PPS_CHANNEL;
116 	fep->reload_period = PPS_OUPUT_RELOAD_PERIOD;
117 	inc = fep->ptp_inc;
118 
119 	spin_lock_irqsave(&fep->tmreg_lock, flags);
120 
121 	if (enable) {
122 		/* clear capture or output compare interrupt status if have.
123 		 */
124 		writel(FEC_T_TF_MASK, fep->hwp + FEC_TCSR(fep->pps_channel));
125 
126 		/* It is recommended to double check the TMODE field in the
127 		 * TCSR register to be cleared before the first compare counter
128 		 * is written into TCCR register. Just add a double check.
129 		 */
130 		val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
131 		do {
132 			val &= ~(FEC_T_TMODE_MASK);
133 			writel(val, fep->hwp + FEC_TCSR(fep->pps_channel));
134 			val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
135 		} while (val & FEC_T_TMODE_MASK);
136 
137 		/* Dummy read counter to update the counter */
138 		timecounter_read(&fep->tc);
139 		/* We want to find the first compare event in the next
140 		 * second point. So we need to know what the ptp time
141 		 * is now and how many nanoseconds is ahead to get next second.
142 		 * The remaining nanosecond ahead before the next second would be
143 		 * NSEC_PER_SEC - ts.tv_nsec. Add the remaining nanoseconds
144 		 * to current timer would be next second.
145 		 */
146 		tempval = readl(fep->hwp + FEC_ATIME_CTRL);
147 		tempval |= FEC_T_CTRL_CAPTURE;
148 		writel(tempval, fep->hwp + FEC_ATIME_CTRL);
149 
150 		tempval = readl(fep->hwp + FEC_ATIME);
151 		/* Convert the ptp local counter to 1588 timestamp */
152 		ns = timecounter_cyc2time(&fep->tc, tempval);
153 		ts = ns_to_timespec64(ns);
154 
155 		/* The tempval is  less than 3 seconds, and  so val is less than
156 		 * 4 seconds. No overflow for 32bit calculation.
157 		 */
158 		val = NSEC_PER_SEC - (u32)ts.tv_nsec + tempval;
159 
160 		/* Need to consider the situation that the current time is
161 		 * very close to the second point, which means NSEC_PER_SEC
162 		 * - ts.tv_nsec is close to be zero(For example 20ns); Since the timer
163 		 * is still running when we calculate the first compare event, it is
164 		 * possible that the remaining nanoseonds run out before the compare
165 		 * counter is calculated and written into TCCR register. To avoid
166 		 * this possibility, we will set the compare event to be the next
167 		 * of next second. The current setting is 31-bit timer and wrap
168 		 * around over 2 seconds. So it is okay to set the next of next
169 		 * seond for the timer.
170 		 */
171 		val += NSEC_PER_SEC;
172 
173 		/* We add (2 * NSEC_PER_SEC - (u32)ts.tv_nsec) to current
174 		 * ptp counter, which maybe cause 32-bit wrap. Since the
175 		 * (NSEC_PER_SEC - (u32)ts.tv_nsec) is less than 2 second.
176 		 * We can ensure the wrap will not cause issue. If the offset
177 		 * is bigger than fep->cc.mask would be a error.
178 		 */
179 		val &= fep->cc.mask;
180 		writel(val, fep->hwp + FEC_TCCR(fep->pps_channel));
181 
182 		/* Calculate the second the compare event timestamp */
183 		fep->next_counter = (val + fep->reload_period) & fep->cc.mask;
184 
185 		/* * Enable compare event when overflow */
186 		val = readl(fep->hwp + FEC_ATIME_CTRL);
187 		val |= FEC_T_CTRL_PINPER;
188 		writel(val, fep->hwp + FEC_ATIME_CTRL);
189 
190 		/* Compare channel setting. */
191 		val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
192 		val |= (1 << FEC_T_TF_OFFSET | 1 << FEC_T_TIE_OFFSET);
193 		val &= ~(1 << FEC_T_TDRE_OFFSET);
194 		val &= ~(FEC_T_TMODE_MASK);
195 		val |= (FEC_HIGH_PULSE << FEC_T_TMODE_OFFSET);
196 		writel(val, fep->hwp + FEC_TCSR(fep->pps_channel));
197 
198 		/* Write the second compare event timestamp and calculate
199 		 * the third timestamp. Refer the TCCR register detail in the spec.
200 		 */
201 		writel(fep->next_counter, fep->hwp + FEC_TCCR(fep->pps_channel));
202 		fep->next_counter = (fep->next_counter + fep->reload_period) & fep->cc.mask;
203 	} else {
204 		writel(0, fep->hwp + FEC_TCSR(fep->pps_channel));
205 	}
206 
207 	fep->pps_enable = enable;
208 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
209 
210 	return 0;
211 }
212 
213 /**
214  * fec_ptp_read - read raw cycle counter (to be used by time counter)
215  * @cc: the cyclecounter structure
216  *
217  * this function reads the cyclecounter registers and is called by the
218  * cyclecounter structure used to construct a ns counter from the
219  * arbitrary fixed point registers
220  */
221 static u64 fec_ptp_read(const struct cyclecounter *cc)
222 {
223 	struct fec_enet_private *fep =
224 		container_of(cc, struct fec_enet_private, cc);
225 	const struct platform_device_id *id_entry =
226 		platform_get_device_id(fep->pdev);
227 	u32 tempval;
228 
229 	tempval = readl(fep->hwp + FEC_ATIME_CTRL);
230 	tempval |= FEC_T_CTRL_CAPTURE;
231 	writel(tempval, fep->hwp + FEC_ATIME_CTRL);
232 
233 	if (id_entry->driver_data & FEC_QUIRK_BUG_CAPTURE)
234 		udelay(1);
235 
236 	return readl(fep->hwp + FEC_ATIME);
237 }
238 
239 /**
240  * fec_ptp_start_cyclecounter - create the cycle counter from hw
241  * @ndev: network device
242  *
243  * this function initializes the timecounter and cyclecounter
244  * structures for use in generated a ns counter from the arbitrary
245  * fixed point cycles registers in the hardware.
246  */
247 void fec_ptp_start_cyclecounter(struct net_device *ndev)
248 {
249 	struct fec_enet_private *fep = netdev_priv(ndev);
250 	unsigned long flags;
251 	int inc;
252 
253 	inc = 1000000000 / fep->cycle_speed;
254 
255 	/* grab the ptp lock */
256 	spin_lock_irqsave(&fep->tmreg_lock, flags);
257 
258 	/* 1ns counter */
259 	writel(inc << FEC_T_INC_OFFSET, fep->hwp + FEC_ATIME_INC);
260 
261 	/* use 31-bit timer counter */
262 	writel(FEC_COUNTER_PERIOD, fep->hwp + FEC_ATIME_EVT_PERIOD);
263 
264 	writel(FEC_T_CTRL_ENABLE | FEC_T_CTRL_PERIOD_RST,
265 		fep->hwp + FEC_ATIME_CTRL);
266 
267 	memset(&fep->cc, 0, sizeof(fep->cc));
268 	fep->cc.read = fec_ptp_read;
269 	fep->cc.mask = CLOCKSOURCE_MASK(31);
270 	fep->cc.shift = 31;
271 	fep->cc.mult = FEC_CC_MULT;
272 
273 	/* reset the ns time counter */
274 	timecounter_init(&fep->tc, &fep->cc, ktime_to_ns(ktime_get_real()));
275 
276 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
277 }
278 
279 /**
280  * fec_ptp_adjfreq - adjust ptp cycle frequency
281  * @ptp: the ptp clock structure
282  * @ppb: parts per billion adjustment from base
283  *
284  * Adjust the frequency of the ptp cycle counter by the
285  * indicated ppb from the base frequency.
286  *
287  * Because ENET hardware frequency adjust is complex,
288  * using software method to do that.
289  */
290 static int fec_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
291 {
292 	unsigned long flags;
293 	int neg_adj = 0;
294 	u32 i, tmp;
295 	u32 corr_inc, corr_period;
296 	u32 corr_ns;
297 	u64 lhs, rhs;
298 
299 	struct fec_enet_private *fep =
300 	    container_of(ptp, struct fec_enet_private, ptp_caps);
301 
302 	if (ppb == 0)
303 		return 0;
304 
305 	if (ppb < 0) {
306 		ppb = -ppb;
307 		neg_adj = 1;
308 	}
309 
310 	/* In theory, corr_inc/corr_period = ppb/NSEC_PER_SEC;
311 	 * Try to find the corr_inc  between 1 to fep->ptp_inc to
312 	 * meet adjustment requirement.
313 	 */
314 	lhs = NSEC_PER_SEC;
315 	rhs = (u64)ppb * (u64)fep->ptp_inc;
316 	for (i = 1; i <= fep->ptp_inc; i++) {
317 		if (lhs >= rhs) {
318 			corr_inc = i;
319 			corr_period = div_u64(lhs, rhs);
320 			break;
321 		}
322 		lhs += NSEC_PER_SEC;
323 	}
324 	/* Not found? Set it to high value - double speed
325 	 * correct in every clock step.
326 	 */
327 	if (i > fep->ptp_inc) {
328 		corr_inc = fep->ptp_inc;
329 		corr_period = 1;
330 	}
331 
332 	if (neg_adj)
333 		corr_ns = fep->ptp_inc - corr_inc;
334 	else
335 		corr_ns = fep->ptp_inc + corr_inc;
336 
337 	spin_lock_irqsave(&fep->tmreg_lock, flags);
338 
339 	tmp = readl(fep->hwp + FEC_ATIME_INC) & FEC_T_INC_MASK;
340 	tmp |= corr_ns << FEC_T_INC_CORR_OFFSET;
341 	writel(tmp, fep->hwp + FEC_ATIME_INC);
342 	corr_period = corr_period > 1 ? corr_period - 1 : corr_period;
343 	writel(corr_period, fep->hwp + FEC_ATIME_CORR);
344 	/* dummy read to update the timer. */
345 	timecounter_read(&fep->tc);
346 
347 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
348 
349 	return 0;
350 }
351 
352 /**
353  * fec_ptp_adjtime
354  * @ptp: the ptp clock structure
355  * @delta: offset to adjust the cycle counter by
356  *
357  * adjust the timer by resetting the timecounter structure.
358  */
359 static int fec_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
360 {
361 	struct fec_enet_private *fep =
362 	    container_of(ptp, struct fec_enet_private, ptp_caps);
363 	unsigned long flags;
364 
365 	spin_lock_irqsave(&fep->tmreg_lock, flags);
366 	timecounter_adjtime(&fep->tc, delta);
367 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
368 
369 	return 0;
370 }
371 
372 /**
373  * fec_ptp_gettime
374  * @ptp: the ptp clock structure
375  * @ts: timespec structure to hold the current time value
376  *
377  * read the timecounter and return the correct value on ns,
378  * after converting it into a struct timespec.
379  */
380 static int fec_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
381 {
382 	struct fec_enet_private *adapter =
383 	    container_of(ptp, struct fec_enet_private, ptp_caps);
384 	u64 ns;
385 	unsigned long flags;
386 
387 	spin_lock_irqsave(&adapter->tmreg_lock, flags);
388 	ns = timecounter_read(&adapter->tc);
389 	spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
390 
391 	*ts = ns_to_timespec64(ns);
392 
393 	return 0;
394 }
395 
396 /**
397  * fec_ptp_settime
398  * @ptp: the ptp clock structure
399  * @ts: the timespec containing the new time for the cycle counter
400  *
401  * reset the timecounter to use a new base value instead of the kernel
402  * wall timer value.
403  */
404 static int fec_ptp_settime(struct ptp_clock_info *ptp,
405 			   const struct timespec64 *ts)
406 {
407 	struct fec_enet_private *fep =
408 	    container_of(ptp, struct fec_enet_private, ptp_caps);
409 
410 	u64 ns;
411 	unsigned long flags;
412 	u32 counter;
413 
414 	mutex_lock(&fep->ptp_clk_mutex);
415 	/* Check the ptp clock */
416 	if (!fep->ptp_clk_on) {
417 		mutex_unlock(&fep->ptp_clk_mutex);
418 		return -EINVAL;
419 	}
420 
421 	ns = timespec64_to_ns(ts);
422 	/* Get the timer value based on timestamp.
423 	 * Update the counter with the masked value.
424 	 */
425 	counter = ns & fep->cc.mask;
426 
427 	spin_lock_irqsave(&fep->tmreg_lock, flags);
428 	writel(counter, fep->hwp + FEC_ATIME);
429 	timecounter_init(&fep->tc, &fep->cc, ns);
430 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
431 	mutex_unlock(&fep->ptp_clk_mutex);
432 	return 0;
433 }
434 
435 /**
436  * fec_ptp_enable
437  * @ptp: the ptp clock structure
438  * @rq: the requested feature to change
439  * @on: whether to enable or disable the feature
440  *
441  */
442 static int fec_ptp_enable(struct ptp_clock_info *ptp,
443 			  struct ptp_clock_request *rq, int on)
444 {
445 	struct fec_enet_private *fep =
446 	    container_of(ptp, struct fec_enet_private, ptp_caps);
447 	int ret = 0;
448 
449 	if (rq->type == PTP_CLK_REQ_PPS) {
450 		ret = fec_ptp_enable_pps(fep, on);
451 
452 		return ret;
453 	}
454 	return -EOPNOTSUPP;
455 }
456 
457 int fec_ptp_set(struct net_device *ndev, struct ifreq *ifr)
458 {
459 	struct fec_enet_private *fep = netdev_priv(ndev);
460 
461 	struct hwtstamp_config config;
462 
463 	if (copy_from_user(&config, ifr->ifr_data, sizeof(config)))
464 		return -EFAULT;
465 
466 	/* reserved for future extensions */
467 	if (config.flags)
468 		return -EINVAL;
469 
470 	switch (config.tx_type) {
471 	case HWTSTAMP_TX_OFF:
472 		fep->hwts_tx_en = 0;
473 		break;
474 	case HWTSTAMP_TX_ON:
475 		fep->hwts_tx_en = 1;
476 		break;
477 	default:
478 		return -ERANGE;
479 	}
480 
481 	switch (config.rx_filter) {
482 	case HWTSTAMP_FILTER_NONE:
483 		if (fep->hwts_rx_en)
484 			fep->hwts_rx_en = 0;
485 		config.rx_filter = HWTSTAMP_FILTER_NONE;
486 		break;
487 
488 	default:
489 		fep->hwts_rx_en = 1;
490 		config.rx_filter = HWTSTAMP_FILTER_ALL;
491 		break;
492 	}
493 
494 	return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
495 	    -EFAULT : 0;
496 }
497 
498 int fec_ptp_get(struct net_device *ndev, struct ifreq *ifr)
499 {
500 	struct fec_enet_private *fep = netdev_priv(ndev);
501 	struct hwtstamp_config config;
502 
503 	config.flags = 0;
504 	config.tx_type = fep->hwts_tx_en ? HWTSTAMP_TX_ON : HWTSTAMP_TX_OFF;
505 	config.rx_filter = (fep->hwts_rx_en ?
506 			    HWTSTAMP_FILTER_ALL : HWTSTAMP_FILTER_NONE);
507 
508 	return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
509 		-EFAULT : 0;
510 }
511 
512 /**
513  * fec_time_keep - call timecounter_read every second to avoid timer overrun
514  *                 because ENET just support 32bit counter, will timeout in 4s
515  */
516 static void fec_time_keep(struct work_struct *work)
517 {
518 	struct delayed_work *dwork = to_delayed_work(work);
519 	struct fec_enet_private *fep = container_of(dwork, struct fec_enet_private, time_keep);
520 	u64 ns;
521 	unsigned long flags;
522 
523 	mutex_lock(&fep->ptp_clk_mutex);
524 	if (fep->ptp_clk_on) {
525 		spin_lock_irqsave(&fep->tmreg_lock, flags);
526 		ns = timecounter_read(&fep->tc);
527 		spin_unlock_irqrestore(&fep->tmreg_lock, flags);
528 	}
529 	mutex_unlock(&fep->ptp_clk_mutex);
530 
531 	schedule_delayed_work(&fep->time_keep, HZ);
532 }
533 
534 /* This function checks the pps event and reloads the timer compare counter. */
535 static irqreturn_t fec_pps_interrupt(int irq, void *dev_id)
536 {
537 	struct net_device *ndev = dev_id;
538 	struct fec_enet_private *fep = netdev_priv(ndev);
539 	u32 val;
540 	u8 channel = fep->pps_channel;
541 	struct ptp_clock_event event;
542 
543 	val = readl(fep->hwp + FEC_TCSR(channel));
544 	if (val & FEC_T_TF_MASK) {
545 		/* Write the next next compare(not the next according the spec)
546 		 * value to the register
547 		 */
548 		writel(fep->next_counter, fep->hwp + FEC_TCCR(channel));
549 		do {
550 			writel(val, fep->hwp + FEC_TCSR(channel));
551 		} while (readl(fep->hwp + FEC_TCSR(channel)) & FEC_T_TF_MASK);
552 
553 		/* Update the counter; */
554 		fep->next_counter = (fep->next_counter + fep->reload_period) &
555 				fep->cc.mask;
556 
557 		event.type = PTP_CLOCK_PPS;
558 		ptp_clock_event(fep->ptp_clock, &event);
559 		return IRQ_HANDLED;
560 	}
561 
562 	return IRQ_NONE;
563 }
564 
565 /**
566  * fec_ptp_init
567  * @ndev: The FEC network adapter
568  *
569  * This function performs the required steps for enabling ptp
570  * support. If ptp support has already been loaded it simply calls the
571  * cyclecounter init routine and exits.
572  */
573 
574 void fec_ptp_init(struct platform_device *pdev, int irq_idx)
575 {
576 	struct net_device *ndev = platform_get_drvdata(pdev);
577 	struct fec_enet_private *fep = netdev_priv(ndev);
578 	int irq;
579 	int ret;
580 
581 	fep->ptp_caps.owner = THIS_MODULE;
582 	snprintf(fep->ptp_caps.name, 16, "fec ptp");
583 
584 	fep->ptp_caps.max_adj = 250000000;
585 	fep->ptp_caps.n_alarm = 0;
586 	fep->ptp_caps.n_ext_ts = 0;
587 	fep->ptp_caps.n_per_out = 0;
588 	fep->ptp_caps.n_pins = 0;
589 	fep->ptp_caps.pps = 1;
590 	fep->ptp_caps.adjfreq = fec_ptp_adjfreq;
591 	fep->ptp_caps.adjtime = fec_ptp_adjtime;
592 	fep->ptp_caps.gettime64 = fec_ptp_gettime;
593 	fep->ptp_caps.settime64 = fec_ptp_settime;
594 	fep->ptp_caps.enable = fec_ptp_enable;
595 
596 	fep->cycle_speed = clk_get_rate(fep->clk_ptp);
597 	fep->ptp_inc = NSEC_PER_SEC / fep->cycle_speed;
598 
599 	spin_lock_init(&fep->tmreg_lock);
600 
601 	fec_ptp_start_cyclecounter(ndev);
602 
603 	INIT_DELAYED_WORK(&fep->time_keep, fec_time_keep);
604 
605 	irq = platform_get_irq_byname(pdev, "pps");
606 	if (irq < 0)
607 		irq = platform_get_irq(pdev, irq_idx);
608 	/* Failure to get an irq is not fatal,
609 	 * only the PTP_CLOCK_PPS clock events should stop
610 	 */
611 	if (irq >= 0) {
612 		ret = devm_request_irq(&pdev->dev, irq, fec_pps_interrupt,
613 				       0, pdev->name, ndev);
614 		if (ret < 0)
615 			dev_warn(&pdev->dev, "request for pps irq failed(%d)\n",
616 				 ret);
617 	}
618 
619 	fep->ptp_clock = ptp_clock_register(&fep->ptp_caps, &pdev->dev);
620 	if (IS_ERR(fep->ptp_clock)) {
621 		fep->ptp_clock = NULL;
622 		pr_err("ptp_clock_register failed\n");
623 	}
624 
625 	schedule_delayed_work(&fep->time_keep, HZ);
626 }
627 
628 void fec_ptp_stop(struct platform_device *pdev)
629 {
630 	struct net_device *ndev = platform_get_drvdata(pdev);
631 	struct fec_enet_private *fep = netdev_priv(ndev);
632 
633 	cancel_delayed_work_sync(&fep->time_keep);
634 	if (fep->ptp_clock)
635 		ptp_clock_unregister(fep->ptp_clock);
636 }
637