1 /*
2  * Fast Ethernet Controller (ENET) PTP driver for MX6x.
3  *
4  * Copyright (C) 2012 Freescale Semiconductor, Inc.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2, as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14  *
15  * You should have received a copy of the GNU General Public License along with
16  * this program; if not, write to the Free Software Foundation, Inc.,
17  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
18  */
19 
20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21 
22 #include <linux/module.h>
23 #include <linux/kernel.h>
24 #include <linux/string.h>
25 #include <linux/ptrace.h>
26 #include <linux/errno.h>
27 #include <linux/ioport.h>
28 #include <linux/slab.h>
29 #include <linux/interrupt.h>
30 #include <linux/pci.h>
31 #include <linux/delay.h>
32 #include <linux/netdevice.h>
33 #include <linux/etherdevice.h>
34 #include <linux/skbuff.h>
35 #include <linux/spinlock.h>
36 #include <linux/workqueue.h>
37 #include <linux/bitops.h>
38 #include <linux/io.h>
39 #include <linux/irq.h>
40 #include <linux/clk.h>
41 #include <linux/platform_device.h>
42 #include <linux/phy.h>
43 #include <linux/fec.h>
44 #include <linux/of.h>
45 #include <linux/of_device.h>
46 #include <linux/of_gpio.h>
47 #include <linux/of_net.h>
48 
49 #include "fec.h"
50 
51 /* FEC 1588 register bits */
52 #define FEC_T_CTRL_SLAVE                0x00002000
53 #define FEC_T_CTRL_CAPTURE              0x00000800
54 #define FEC_T_CTRL_RESTART              0x00000200
55 #define FEC_T_CTRL_PERIOD_RST           0x00000030
56 #define FEC_T_CTRL_PERIOD_EN		0x00000010
57 #define FEC_T_CTRL_ENABLE               0x00000001
58 
59 #define FEC_T_INC_MASK                  0x0000007f
60 #define FEC_T_INC_OFFSET                0
61 #define FEC_T_INC_CORR_MASK             0x00007f00
62 #define FEC_T_INC_CORR_OFFSET           8
63 
64 #define FEC_T_CTRL_PINPER		0x00000080
65 #define FEC_T_TF0_MASK			0x00000001
66 #define FEC_T_TF0_OFFSET		0
67 #define FEC_T_TF1_MASK			0x00000002
68 #define FEC_T_TF1_OFFSET		1
69 #define FEC_T_TF2_MASK			0x00000004
70 #define FEC_T_TF2_OFFSET		2
71 #define FEC_T_TF3_MASK			0x00000008
72 #define FEC_T_TF3_OFFSET		3
73 #define FEC_T_TDRE_MASK			0x00000001
74 #define FEC_T_TDRE_OFFSET		0
75 #define FEC_T_TMODE_MASK		0x0000003C
76 #define FEC_T_TMODE_OFFSET		2
77 #define FEC_T_TIE_MASK			0x00000040
78 #define FEC_T_TIE_OFFSET		6
79 #define FEC_T_TF_MASK			0x00000080
80 #define FEC_T_TF_OFFSET			7
81 
82 #define FEC_ATIME_CTRL		0x400
83 #define FEC_ATIME		0x404
84 #define FEC_ATIME_EVT_OFFSET	0x408
85 #define FEC_ATIME_EVT_PERIOD	0x40c
86 #define FEC_ATIME_CORR		0x410
87 #define FEC_ATIME_INC		0x414
88 #define FEC_TS_TIMESTAMP	0x418
89 
90 #define FEC_TGSR		0x604
91 #define FEC_TCSR(n)		(0x608 + n * 0x08)
92 #define FEC_TCCR(n)		(0x60C + n * 0x08)
93 #define MAX_TIMER_CHANNEL	3
94 #define FEC_TMODE_TOGGLE	0x05
95 #define FEC_HIGH_PULSE		0x0F
96 
97 #define FEC_CC_MULT	(1 << 31)
98 #define FEC_COUNTER_PERIOD	(1 << 31)
99 #define PPS_OUPUT_RELOAD_PERIOD	NSEC_PER_SEC
100 #define FEC_CHANNLE_0		0
101 #define DEFAULT_PPS_CHANNEL	FEC_CHANNLE_0
102 
103 /**
104  * fec_ptp_enable_pps
105  * @fep: the fec_enet_private structure handle
106  * @enable: enable the channel pps output
107  *
108  * This function enble the PPS ouput on the timer channel.
109  */
110 static int fec_ptp_enable_pps(struct fec_enet_private *fep, uint enable)
111 {
112 	unsigned long flags;
113 	u32 val, tempval;
114 	int inc;
115 	struct timespec64 ts;
116 	u64 ns;
117 	val = 0;
118 
119 	if (!(fep->hwts_tx_en || fep->hwts_rx_en)) {
120 		dev_err(&fep->pdev->dev, "No ptp stack is running\n");
121 		return -EINVAL;
122 	}
123 
124 	if (fep->pps_enable == enable)
125 		return 0;
126 
127 	fep->pps_channel = DEFAULT_PPS_CHANNEL;
128 	fep->reload_period = PPS_OUPUT_RELOAD_PERIOD;
129 	inc = fep->ptp_inc;
130 
131 	spin_lock_irqsave(&fep->tmreg_lock, flags);
132 
133 	if (enable) {
134 		/* clear capture or output compare interrupt status if have.
135 		 */
136 		writel(FEC_T_TF_MASK, fep->hwp + FEC_TCSR(fep->pps_channel));
137 
138 		/* It is recommended to double check the TMODE field in the
139 		 * TCSR register to be cleared before the first compare counter
140 		 * is written into TCCR register. Just add a double check.
141 		 */
142 		val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
143 		do {
144 			val &= ~(FEC_T_TMODE_MASK);
145 			writel(val, fep->hwp + FEC_TCSR(fep->pps_channel));
146 			val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
147 		} while (val & FEC_T_TMODE_MASK);
148 
149 		/* Dummy read counter to update the counter */
150 		timecounter_read(&fep->tc);
151 		/* We want to find the first compare event in the next
152 		 * second point. So we need to know what the ptp time
153 		 * is now and how many nanoseconds is ahead to get next second.
154 		 * The remaining nanosecond ahead before the next second would be
155 		 * NSEC_PER_SEC - ts.tv_nsec. Add the remaining nanoseconds
156 		 * to current timer would be next second.
157 		 */
158 		tempval = readl(fep->hwp + FEC_ATIME_CTRL);
159 		tempval |= FEC_T_CTRL_CAPTURE;
160 		writel(tempval, fep->hwp + FEC_ATIME_CTRL);
161 
162 		tempval = readl(fep->hwp + FEC_ATIME);
163 		/* Convert the ptp local counter to 1588 timestamp */
164 		ns = timecounter_cyc2time(&fep->tc, tempval);
165 		ts = ns_to_timespec64(ns);
166 
167 		/* The tempval is  less than 3 seconds, and  so val is less than
168 		 * 4 seconds. No overflow for 32bit calculation.
169 		 */
170 		val = NSEC_PER_SEC - (u32)ts.tv_nsec + tempval;
171 
172 		/* Need to consider the situation that the current time is
173 		 * very close to the second point, which means NSEC_PER_SEC
174 		 * - ts.tv_nsec is close to be zero(For example 20ns); Since the timer
175 		 * is still running when we calculate the first compare event, it is
176 		 * possible that the remaining nanoseonds run out before the compare
177 		 * counter is calculated and written into TCCR register. To avoid
178 		 * this possibility, we will set the compare event to be the next
179 		 * of next second. The current setting is 31-bit timer and wrap
180 		 * around over 2 seconds. So it is okay to set the next of next
181 		 * seond for the timer.
182 		 */
183 		val += NSEC_PER_SEC;
184 
185 		/* We add (2 * NSEC_PER_SEC - (u32)ts.tv_nsec) to current
186 		 * ptp counter, which maybe cause 32-bit wrap. Since the
187 		 * (NSEC_PER_SEC - (u32)ts.tv_nsec) is less than 2 second.
188 		 * We can ensure the wrap will not cause issue. If the offset
189 		 * is bigger than fep->cc.mask would be a error.
190 		 */
191 		val &= fep->cc.mask;
192 		writel(val, fep->hwp + FEC_TCCR(fep->pps_channel));
193 
194 		/* Calculate the second the compare event timestamp */
195 		fep->next_counter = (val + fep->reload_period) & fep->cc.mask;
196 
197 		/* * Enable compare event when overflow */
198 		val = readl(fep->hwp + FEC_ATIME_CTRL);
199 		val |= FEC_T_CTRL_PINPER;
200 		writel(val, fep->hwp + FEC_ATIME_CTRL);
201 
202 		/* Compare channel setting. */
203 		val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
204 		val |= (1 << FEC_T_TF_OFFSET | 1 << FEC_T_TIE_OFFSET);
205 		val &= ~(1 << FEC_T_TDRE_OFFSET);
206 		val &= ~(FEC_T_TMODE_MASK);
207 		val |= (FEC_HIGH_PULSE << FEC_T_TMODE_OFFSET);
208 		writel(val, fep->hwp + FEC_TCSR(fep->pps_channel));
209 
210 		/* Write the second compare event timestamp and calculate
211 		 * the third timestamp. Refer the TCCR register detail in the spec.
212 		 */
213 		writel(fep->next_counter, fep->hwp + FEC_TCCR(fep->pps_channel));
214 		fep->next_counter = (fep->next_counter + fep->reload_period) & fep->cc.mask;
215 	} else {
216 		writel(0, fep->hwp + FEC_TCSR(fep->pps_channel));
217 	}
218 
219 	fep->pps_enable = enable;
220 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
221 
222 	return 0;
223 }
224 
225 /**
226  * fec_ptp_read - read raw cycle counter (to be used by time counter)
227  * @cc: the cyclecounter structure
228  *
229  * this function reads the cyclecounter registers and is called by the
230  * cyclecounter structure used to construct a ns counter from the
231  * arbitrary fixed point registers
232  */
233 static u64 fec_ptp_read(const struct cyclecounter *cc)
234 {
235 	struct fec_enet_private *fep =
236 		container_of(cc, struct fec_enet_private, cc);
237 	const struct platform_device_id *id_entry =
238 		platform_get_device_id(fep->pdev);
239 	u32 tempval;
240 
241 	tempval = readl(fep->hwp + FEC_ATIME_CTRL);
242 	tempval |= FEC_T_CTRL_CAPTURE;
243 	writel(tempval, fep->hwp + FEC_ATIME_CTRL);
244 
245 	if (id_entry->driver_data & FEC_QUIRK_BUG_CAPTURE)
246 		udelay(1);
247 
248 	return readl(fep->hwp + FEC_ATIME);
249 }
250 
251 /**
252  * fec_ptp_start_cyclecounter - create the cycle counter from hw
253  * @ndev: network device
254  *
255  * this function initializes the timecounter and cyclecounter
256  * structures for use in generated a ns counter from the arbitrary
257  * fixed point cycles registers in the hardware.
258  */
259 void fec_ptp_start_cyclecounter(struct net_device *ndev)
260 {
261 	struct fec_enet_private *fep = netdev_priv(ndev);
262 	unsigned long flags;
263 	int inc;
264 
265 	inc = 1000000000 / fep->cycle_speed;
266 
267 	/* grab the ptp lock */
268 	spin_lock_irqsave(&fep->tmreg_lock, flags);
269 
270 	/* 1ns counter */
271 	writel(inc << FEC_T_INC_OFFSET, fep->hwp + FEC_ATIME_INC);
272 
273 	/* use 31-bit timer counter */
274 	writel(FEC_COUNTER_PERIOD, fep->hwp + FEC_ATIME_EVT_PERIOD);
275 
276 	writel(FEC_T_CTRL_ENABLE | FEC_T_CTRL_PERIOD_RST,
277 		fep->hwp + FEC_ATIME_CTRL);
278 
279 	memset(&fep->cc, 0, sizeof(fep->cc));
280 	fep->cc.read = fec_ptp_read;
281 	fep->cc.mask = CLOCKSOURCE_MASK(31);
282 	fep->cc.shift = 31;
283 	fep->cc.mult = FEC_CC_MULT;
284 
285 	/* reset the ns time counter */
286 	timecounter_init(&fep->tc, &fep->cc, ktime_to_ns(ktime_get_real()));
287 
288 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
289 }
290 
291 /**
292  * fec_ptp_adjfreq - adjust ptp cycle frequency
293  * @ptp: the ptp clock structure
294  * @ppb: parts per billion adjustment from base
295  *
296  * Adjust the frequency of the ptp cycle counter by the
297  * indicated ppb from the base frequency.
298  *
299  * Because ENET hardware frequency adjust is complex,
300  * using software method to do that.
301  */
302 static int fec_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
303 {
304 	unsigned long flags;
305 	int neg_adj = 0;
306 	u32 i, tmp;
307 	u32 corr_inc, corr_period;
308 	u32 corr_ns;
309 	u64 lhs, rhs;
310 
311 	struct fec_enet_private *fep =
312 	    container_of(ptp, struct fec_enet_private, ptp_caps);
313 
314 	if (ppb == 0)
315 		return 0;
316 
317 	if (ppb < 0) {
318 		ppb = -ppb;
319 		neg_adj = 1;
320 	}
321 
322 	/* In theory, corr_inc/corr_period = ppb/NSEC_PER_SEC;
323 	 * Try to find the corr_inc  between 1 to fep->ptp_inc to
324 	 * meet adjustment requirement.
325 	 */
326 	lhs = NSEC_PER_SEC;
327 	rhs = (u64)ppb * (u64)fep->ptp_inc;
328 	for (i = 1; i <= fep->ptp_inc; i++) {
329 		if (lhs >= rhs) {
330 			corr_inc = i;
331 			corr_period = div_u64(lhs, rhs);
332 			break;
333 		}
334 		lhs += NSEC_PER_SEC;
335 	}
336 	/* Not found? Set it to high value - double speed
337 	 * correct in every clock step.
338 	 */
339 	if (i > fep->ptp_inc) {
340 		corr_inc = fep->ptp_inc;
341 		corr_period = 1;
342 	}
343 
344 	if (neg_adj)
345 		corr_ns = fep->ptp_inc - corr_inc;
346 	else
347 		corr_ns = fep->ptp_inc + corr_inc;
348 
349 	spin_lock_irqsave(&fep->tmreg_lock, flags);
350 
351 	tmp = readl(fep->hwp + FEC_ATIME_INC) & FEC_T_INC_MASK;
352 	tmp |= corr_ns << FEC_T_INC_CORR_OFFSET;
353 	writel(tmp, fep->hwp + FEC_ATIME_INC);
354 	corr_period = corr_period > 1 ? corr_period - 1 : corr_period;
355 	writel(corr_period, fep->hwp + FEC_ATIME_CORR);
356 	/* dummy read to update the timer. */
357 	timecounter_read(&fep->tc);
358 
359 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
360 
361 	return 0;
362 }
363 
364 /**
365  * fec_ptp_adjtime
366  * @ptp: the ptp clock structure
367  * @delta: offset to adjust the cycle counter by
368  *
369  * adjust the timer by resetting the timecounter structure.
370  */
371 static int fec_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
372 {
373 	struct fec_enet_private *fep =
374 	    container_of(ptp, struct fec_enet_private, ptp_caps);
375 	unsigned long flags;
376 
377 	spin_lock_irqsave(&fep->tmreg_lock, flags);
378 	timecounter_adjtime(&fep->tc, delta);
379 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
380 
381 	return 0;
382 }
383 
384 /**
385  * fec_ptp_gettime
386  * @ptp: the ptp clock structure
387  * @ts: timespec structure to hold the current time value
388  *
389  * read the timecounter and return the correct value on ns,
390  * after converting it into a struct timespec.
391  */
392 static int fec_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
393 {
394 	struct fec_enet_private *adapter =
395 	    container_of(ptp, struct fec_enet_private, ptp_caps);
396 	u64 ns;
397 	unsigned long flags;
398 
399 	spin_lock_irqsave(&adapter->tmreg_lock, flags);
400 	ns = timecounter_read(&adapter->tc);
401 	spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
402 
403 	*ts = ns_to_timespec64(ns);
404 
405 	return 0;
406 }
407 
408 /**
409  * fec_ptp_settime
410  * @ptp: the ptp clock structure
411  * @ts: the timespec containing the new time for the cycle counter
412  *
413  * reset the timecounter to use a new base value instead of the kernel
414  * wall timer value.
415  */
416 static int fec_ptp_settime(struct ptp_clock_info *ptp,
417 			   const struct timespec64 *ts)
418 {
419 	struct fec_enet_private *fep =
420 	    container_of(ptp, struct fec_enet_private, ptp_caps);
421 
422 	u64 ns;
423 	unsigned long flags;
424 	u32 counter;
425 
426 	mutex_lock(&fep->ptp_clk_mutex);
427 	/* Check the ptp clock */
428 	if (!fep->ptp_clk_on) {
429 		mutex_unlock(&fep->ptp_clk_mutex);
430 		return -EINVAL;
431 	}
432 
433 	ns = timespec64_to_ns(ts);
434 	/* Get the timer value based on timestamp.
435 	 * Update the counter with the masked value.
436 	 */
437 	counter = ns & fep->cc.mask;
438 
439 	spin_lock_irqsave(&fep->tmreg_lock, flags);
440 	writel(counter, fep->hwp + FEC_ATIME);
441 	timecounter_init(&fep->tc, &fep->cc, ns);
442 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
443 	mutex_unlock(&fep->ptp_clk_mutex);
444 	return 0;
445 }
446 
447 /**
448  * fec_ptp_enable
449  * @ptp: the ptp clock structure
450  * @rq: the requested feature to change
451  * @on: whether to enable or disable the feature
452  *
453  */
454 static int fec_ptp_enable(struct ptp_clock_info *ptp,
455 			  struct ptp_clock_request *rq, int on)
456 {
457 	struct fec_enet_private *fep =
458 	    container_of(ptp, struct fec_enet_private, ptp_caps);
459 	int ret = 0;
460 
461 	if (rq->type == PTP_CLK_REQ_PPS) {
462 		ret = fec_ptp_enable_pps(fep, on);
463 
464 		return ret;
465 	}
466 	return -EOPNOTSUPP;
467 }
468 
469 /**
470  * fec_ptp_hwtstamp_ioctl - control hardware time stamping
471  * @ndev: pointer to net_device
472  * @ifreq: ioctl data
473  * @cmd: particular ioctl requested
474  */
475 int fec_ptp_set(struct net_device *ndev, struct ifreq *ifr)
476 {
477 	struct fec_enet_private *fep = netdev_priv(ndev);
478 
479 	struct hwtstamp_config config;
480 
481 	if (copy_from_user(&config, ifr->ifr_data, sizeof(config)))
482 		return -EFAULT;
483 
484 	/* reserved for future extensions */
485 	if (config.flags)
486 		return -EINVAL;
487 
488 	switch (config.tx_type) {
489 	case HWTSTAMP_TX_OFF:
490 		fep->hwts_tx_en = 0;
491 		break;
492 	case HWTSTAMP_TX_ON:
493 		fep->hwts_tx_en = 1;
494 		break;
495 	default:
496 		return -ERANGE;
497 	}
498 
499 	switch (config.rx_filter) {
500 	case HWTSTAMP_FILTER_NONE:
501 		if (fep->hwts_rx_en)
502 			fep->hwts_rx_en = 0;
503 		config.rx_filter = HWTSTAMP_FILTER_NONE;
504 		break;
505 
506 	default:
507 		fep->hwts_rx_en = 1;
508 		config.rx_filter = HWTSTAMP_FILTER_ALL;
509 		break;
510 	}
511 
512 	return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
513 	    -EFAULT : 0;
514 }
515 
516 int fec_ptp_get(struct net_device *ndev, struct ifreq *ifr)
517 {
518 	struct fec_enet_private *fep = netdev_priv(ndev);
519 	struct hwtstamp_config config;
520 
521 	config.flags = 0;
522 	config.tx_type = fep->hwts_tx_en ? HWTSTAMP_TX_ON : HWTSTAMP_TX_OFF;
523 	config.rx_filter = (fep->hwts_rx_en ?
524 			    HWTSTAMP_FILTER_ALL : HWTSTAMP_FILTER_NONE);
525 
526 	return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
527 		-EFAULT : 0;
528 }
529 
530 /**
531  * fec_time_keep - call timecounter_read every second to avoid timer overrun
532  *                 because ENET just support 32bit counter, will timeout in 4s
533  */
534 static void fec_time_keep(struct work_struct *work)
535 {
536 	struct delayed_work *dwork = to_delayed_work(work);
537 	struct fec_enet_private *fep = container_of(dwork, struct fec_enet_private, time_keep);
538 	u64 ns;
539 	unsigned long flags;
540 
541 	mutex_lock(&fep->ptp_clk_mutex);
542 	if (fep->ptp_clk_on) {
543 		spin_lock_irqsave(&fep->tmreg_lock, flags);
544 		ns = timecounter_read(&fep->tc);
545 		spin_unlock_irqrestore(&fep->tmreg_lock, flags);
546 	}
547 	mutex_unlock(&fep->ptp_clk_mutex);
548 
549 	schedule_delayed_work(&fep->time_keep, HZ);
550 }
551 
552 /**
553  * fec_ptp_init
554  * @ndev: The FEC network adapter
555  *
556  * This function performs the required steps for enabling ptp
557  * support. If ptp support has already been loaded it simply calls the
558  * cyclecounter init routine and exits.
559  */
560 
561 void fec_ptp_init(struct platform_device *pdev)
562 {
563 	struct net_device *ndev = platform_get_drvdata(pdev);
564 	struct fec_enet_private *fep = netdev_priv(ndev);
565 
566 	fep->ptp_caps.owner = THIS_MODULE;
567 	snprintf(fep->ptp_caps.name, 16, "fec ptp");
568 
569 	fep->ptp_caps.max_adj = 250000000;
570 	fep->ptp_caps.n_alarm = 0;
571 	fep->ptp_caps.n_ext_ts = 0;
572 	fep->ptp_caps.n_per_out = 0;
573 	fep->ptp_caps.n_pins = 0;
574 	fep->ptp_caps.pps = 1;
575 	fep->ptp_caps.adjfreq = fec_ptp_adjfreq;
576 	fep->ptp_caps.adjtime = fec_ptp_adjtime;
577 	fep->ptp_caps.gettime64 = fec_ptp_gettime;
578 	fep->ptp_caps.settime64 = fec_ptp_settime;
579 	fep->ptp_caps.enable = fec_ptp_enable;
580 
581 	fep->cycle_speed = clk_get_rate(fep->clk_ptp);
582 	fep->ptp_inc = NSEC_PER_SEC / fep->cycle_speed;
583 
584 	spin_lock_init(&fep->tmreg_lock);
585 
586 	fec_ptp_start_cyclecounter(ndev);
587 
588 	INIT_DELAYED_WORK(&fep->time_keep, fec_time_keep);
589 
590 	fep->ptp_clock = ptp_clock_register(&fep->ptp_caps, &pdev->dev);
591 	if (IS_ERR(fep->ptp_clock)) {
592 		fep->ptp_clock = NULL;
593 		pr_err("ptp_clock_register failed\n");
594 	}
595 
596 	schedule_delayed_work(&fep->time_keep, HZ);
597 }
598 
599 void fec_ptp_stop(struct platform_device *pdev)
600 {
601 	struct net_device *ndev = platform_get_drvdata(pdev);
602 	struct fec_enet_private *fep = netdev_priv(ndev);
603 
604 	cancel_delayed_work_sync(&fep->time_keep);
605 	if (fep->ptp_clock)
606 		ptp_clock_unregister(fep->ptp_clock);
607 }
608 
609 /**
610  * fec_ptp_check_pps_event
611  * @fep: the fec_enet_private structure handle
612  *
613  * This function check the pps event and reload the timer compare counter.
614  */
615 uint fec_ptp_check_pps_event(struct fec_enet_private *fep)
616 {
617 	u32 val;
618 	u8 channel = fep->pps_channel;
619 	struct ptp_clock_event event;
620 
621 	val = readl(fep->hwp + FEC_TCSR(channel));
622 	if (val & FEC_T_TF_MASK) {
623 		/* Write the next next compare(not the next according the spec)
624 		 * value to the register
625 		 */
626 		writel(fep->next_counter, fep->hwp + FEC_TCCR(channel));
627 		do {
628 			writel(val, fep->hwp + FEC_TCSR(channel));
629 		} while (readl(fep->hwp + FEC_TCSR(channel)) & FEC_T_TF_MASK);
630 
631 		/* Update the counter; */
632 		fep->next_counter = (fep->next_counter + fep->reload_period) & fep->cc.mask;
633 
634 		event.type = PTP_CLOCK_PPS;
635 		ptp_clock_event(fep->ptp_clock, &event);
636 		return 1;
637 	}
638 
639 	return 0;
640 }
641