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_gpio.h>
34 #include <linux/of_net.h>
35 
36 #include "fec.h"
37 
38 /* FEC 1588 register bits */
39 #define FEC_T_CTRL_SLAVE                0x00002000
40 #define FEC_T_CTRL_CAPTURE              0x00000800
41 #define FEC_T_CTRL_RESTART              0x00000200
42 #define FEC_T_CTRL_PERIOD_RST           0x00000030
43 #define FEC_T_CTRL_PERIOD_EN		0x00000010
44 #define FEC_T_CTRL_ENABLE               0x00000001
45 
46 #define FEC_T_INC_MASK                  0x0000007f
47 #define FEC_T_INC_OFFSET                0
48 #define FEC_T_INC_CORR_MASK             0x00007f00
49 #define FEC_T_INC_CORR_OFFSET           8
50 
51 #define FEC_T_CTRL_PINPER		0x00000080
52 #define FEC_T_TF0_MASK			0x00000001
53 #define FEC_T_TF0_OFFSET		0
54 #define FEC_T_TF1_MASK			0x00000002
55 #define FEC_T_TF1_OFFSET		1
56 #define FEC_T_TF2_MASK			0x00000004
57 #define FEC_T_TF2_OFFSET		2
58 #define FEC_T_TF3_MASK			0x00000008
59 #define FEC_T_TF3_OFFSET		3
60 #define FEC_T_TDRE_MASK			0x00000001
61 #define FEC_T_TDRE_OFFSET		0
62 #define FEC_T_TMODE_MASK		0x0000003C
63 #define FEC_T_TMODE_OFFSET		2
64 #define FEC_T_TIE_MASK			0x00000040
65 #define FEC_T_TIE_OFFSET		6
66 #define FEC_T_TF_MASK			0x00000080
67 #define FEC_T_TF_OFFSET			7
68 
69 #define FEC_ATIME_CTRL		0x400
70 #define FEC_ATIME		0x404
71 #define FEC_ATIME_EVT_OFFSET	0x408
72 #define FEC_ATIME_EVT_PERIOD	0x40c
73 #define FEC_ATIME_CORR		0x410
74 #define FEC_ATIME_INC		0x414
75 #define FEC_TS_TIMESTAMP	0x418
76 
77 #define FEC_TGSR		0x604
78 #define FEC_TCSR(n)		(0x608 + n * 0x08)
79 #define FEC_TCCR(n)		(0x60C + n * 0x08)
80 #define MAX_TIMER_CHANNEL	3
81 #define FEC_TMODE_TOGGLE	0x05
82 #define FEC_HIGH_PULSE		0x0F
83 
84 #define FEC_CC_MULT	(1 << 31)
85 #define FEC_COUNTER_PERIOD	(1 << 31)
86 #define PPS_OUPUT_RELOAD_PERIOD	NSEC_PER_SEC
87 #define FEC_CHANNLE_0		0
88 #define DEFAULT_PPS_CHANNEL	FEC_CHANNLE_0
89 
90 #define FEC_PTP_MAX_NSEC_PERIOD		4000000000ULL
91 #define FEC_PTP_MAX_NSEC_COUNTER	0x80000000ULL
92 
93 /**
94  * fec_ptp_enable_pps
95  * @fep: the fec_enet_private structure handle
96  * @enable: enable the channel pps output
97  *
98  * This function enble the PPS ouput on the timer channel.
99  */
100 static int fec_ptp_enable_pps(struct fec_enet_private *fep, uint enable)
101 {
102 	unsigned long flags;
103 	u32 val, tempval;
104 	struct timespec64 ts;
105 	u64 ns;
106 
107 	if (fep->pps_enable == enable)
108 		return 0;
109 
110 	fep->pps_channel = DEFAULT_PPS_CHANNEL;
111 	fep->reload_period = PPS_OUPUT_RELOAD_PERIOD;
112 
113 	spin_lock_irqsave(&fep->tmreg_lock, flags);
114 
115 	if (enable) {
116 		/* clear capture or output compare interrupt status if have.
117 		 */
118 		writel(FEC_T_TF_MASK, fep->hwp + FEC_TCSR(fep->pps_channel));
119 
120 		/* It is recommended to double check the TMODE field in the
121 		 * TCSR register to be cleared before the first compare counter
122 		 * is written into TCCR register. Just add a double check.
123 		 */
124 		val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
125 		do {
126 			val &= ~(FEC_T_TMODE_MASK);
127 			writel(val, fep->hwp + FEC_TCSR(fep->pps_channel));
128 			val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
129 		} while (val & FEC_T_TMODE_MASK);
130 
131 		/* Dummy read counter to update the counter */
132 		timecounter_read(&fep->tc);
133 		/* We want to find the first compare event in the next
134 		 * second point. So we need to know what the ptp time
135 		 * is now and how many nanoseconds is ahead to get next second.
136 		 * The remaining nanosecond ahead before the next second would be
137 		 * NSEC_PER_SEC - ts.tv_nsec. Add the remaining nanoseconds
138 		 * to current timer would be next second.
139 		 */
140 		tempval = fep->cc.read(&fep->cc);
141 		/* Convert the ptp local counter to 1588 timestamp */
142 		ns = timecounter_cyc2time(&fep->tc, tempval);
143 		ts = ns_to_timespec64(ns);
144 
145 		/* The tempval is  less than 3 seconds, and  so val is less than
146 		 * 4 seconds. No overflow for 32bit calculation.
147 		 */
148 		val = NSEC_PER_SEC - (u32)ts.tv_nsec + tempval;
149 
150 		/* Need to consider the situation that the current time is
151 		 * very close to the second point, which means NSEC_PER_SEC
152 		 * - ts.tv_nsec is close to be zero(For example 20ns); Since the timer
153 		 * is still running when we calculate the first compare event, it is
154 		 * possible that the remaining nanoseonds run out before the compare
155 		 * counter is calculated and written into TCCR register. To avoid
156 		 * this possibility, we will set the compare event to be the next
157 		 * of next second. The current setting is 31-bit timer and wrap
158 		 * around over 2 seconds. So it is okay to set the next of next
159 		 * seond for the timer.
160 		 */
161 		val += NSEC_PER_SEC;
162 
163 		/* We add (2 * NSEC_PER_SEC - (u32)ts.tv_nsec) to current
164 		 * ptp counter, which maybe cause 32-bit wrap. Since the
165 		 * (NSEC_PER_SEC - (u32)ts.tv_nsec) is less than 2 second.
166 		 * We can ensure the wrap will not cause issue. If the offset
167 		 * is bigger than fep->cc.mask would be a error.
168 		 */
169 		val &= fep->cc.mask;
170 		writel(val, fep->hwp + FEC_TCCR(fep->pps_channel));
171 
172 		/* Calculate the second the compare event timestamp */
173 		fep->next_counter = (val + fep->reload_period) & fep->cc.mask;
174 
175 		/* * Enable compare event when overflow */
176 		val = readl(fep->hwp + FEC_ATIME_CTRL);
177 		val |= FEC_T_CTRL_PINPER;
178 		writel(val, fep->hwp + FEC_ATIME_CTRL);
179 
180 		/* Compare channel setting. */
181 		val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
182 		val |= (1 << FEC_T_TF_OFFSET | 1 << FEC_T_TIE_OFFSET);
183 		val &= ~(1 << FEC_T_TDRE_OFFSET);
184 		val &= ~(FEC_T_TMODE_MASK);
185 		val |= (FEC_HIGH_PULSE << FEC_T_TMODE_OFFSET);
186 		writel(val, fep->hwp + FEC_TCSR(fep->pps_channel));
187 
188 		/* Write the second compare event timestamp and calculate
189 		 * the third timestamp. Refer the TCCR register detail in the spec.
190 		 */
191 		writel(fep->next_counter, fep->hwp + FEC_TCCR(fep->pps_channel));
192 		fep->next_counter = (fep->next_counter + fep->reload_period) & fep->cc.mask;
193 	} else {
194 		writel(0, fep->hwp + FEC_TCSR(fep->pps_channel));
195 	}
196 
197 	fep->pps_enable = enable;
198 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
199 
200 	return 0;
201 }
202 
203 static int fec_ptp_pps_perout(struct fec_enet_private *fep)
204 {
205 	u32 compare_val, ptp_hc, temp_val;
206 	u64 curr_time;
207 	unsigned long flags;
208 
209 	spin_lock_irqsave(&fep->tmreg_lock, flags);
210 
211 	/* Update time counter */
212 	timecounter_read(&fep->tc);
213 
214 	/* Get the current ptp hardware time counter */
215 	temp_val = readl(fep->hwp + FEC_ATIME_CTRL);
216 	temp_val |= FEC_T_CTRL_CAPTURE;
217 	writel(temp_val, fep->hwp + FEC_ATIME_CTRL);
218 	if (fep->quirks & FEC_QUIRK_BUG_CAPTURE)
219 		udelay(1);
220 
221 	ptp_hc = readl(fep->hwp + FEC_ATIME);
222 
223 	/* Convert the ptp local counter to 1588 timestamp */
224 	curr_time = timecounter_cyc2time(&fep->tc, ptp_hc);
225 
226 	/* If the pps start time less than current time add 100ms, just return.
227 	 * Because the software might not able to set the comparison time into
228 	 * the FEC_TCCR register in time and missed the start time.
229 	 */
230 	if (fep->perout_stime < curr_time + 100 * NSEC_PER_MSEC) {
231 		dev_err(&fep->pdev->dev, "Current time is too close to the start time!\n");
232 		spin_unlock_irqrestore(&fep->tmreg_lock, flags);
233 		return -1;
234 	}
235 
236 	compare_val = fep->perout_stime - curr_time + ptp_hc;
237 	compare_val &= fep->cc.mask;
238 
239 	writel(compare_val, fep->hwp + FEC_TCCR(fep->pps_channel));
240 	fep->next_counter = (compare_val + fep->reload_period) & fep->cc.mask;
241 
242 	/* Enable compare event when overflow */
243 	temp_val = readl(fep->hwp + FEC_ATIME_CTRL);
244 	temp_val |= FEC_T_CTRL_PINPER;
245 	writel(temp_val, fep->hwp + FEC_ATIME_CTRL);
246 
247 	/* Compare channel setting. */
248 	temp_val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
249 	temp_val |= (1 << FEC_T_TF_OFFSET | 1 << FEC_T_TIE_OFFSET);
250 	temp_val &= ~(1 << FEC_T_TDRE_OFFSET);
251 	temp_val &= ~(FEC_T_TMODE_MASK);
252 	temp_val |= (FEC_TMODE_TOGGLE << FEC_T_TMODE_OFFSET);
253 	writel(temp_val, fep->hwp + FEC_TCSR(fep->pps_channel));
254 
255 	/* Write the second compare event timestamp and calculate
256 	 * the third timestamp. Refer the TCCR register detail in the spec.
257 	 */
258 	writel(fep->next_counter, fep->hwp + FEC_TCCR(fep->pps_channel));
259 	fep->next_counter = (fep->next_counter + fep->reload_period) & fep->cc.mask;
260 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
261 
262 	return 0;
263 }
264 
265 static enum hrtimer_restart fec_ptp_pps_perout_handler(struct hrtimer *timer)
266 {
267 	struct fec_enet_private *fep = container_of(timer,
268 					struct fec_enet_private, perout_timer);
269 
270 	fec_ptp_pps_perout(fep);
271 
272 	return HRTIMER_NORESTART;
273 }
274 
275 /**
276  * fec_ptp_read - read raw cycle counter (to be used by time counter)
277  * @cc: the cyclecounter structure
278  *
279  * this function reads the cyclecounter registers and is called by the
280  * cyclecounter structure used to construct a ns counter from the
281  * arbitrary fixed point registers
282  */
283 static u64 fec_ptp_read(const struct cyclecounter *cc)
284 {
285 	struct fec_enet_private *fep =
286 		container_of(cc, struct fec_enet_private, cc);
287 	u32 tempval;
288 
289 	tempval = readl(fep->hwp + FEC_ATIME_CTRL);
290 	tempval |= FEC_T_CTRL_CAPTURE;
291 	writel(tempval, fep->hwp + FEC_ATIME_CTRL);
292 
293 	if (fep->quirks & FEC_QUIRK_BUG_CAPTURE)
294 		udelay(1);
295 
296 	return readl(fep->hwp + FEC_ATIME);
297 }
298 
299 /**
300  * fec_ptp_start_cyclecounter - create the cycle counter from hw
301  * @ndev: network device
302  *
303  * this function initializes the timecounter and cyclecounter
304  * structures for use in generated a ns counter from the arbitrary
305  * fixed point cycles registers in the hardware.
306  */
307 void fec_ptp_start_cyclecounter(struct net_device *ndev)
308 {
309 	struct fec_enet_private *fep = netdev_priv(ndev);
310 	unsigned long flags;
311 	int inc;
312 
313 	inc = 1000000000 / fep->cycle_speed;
314 
315 	/* grab the ptp lock */
316 	spin_lock_irqsave(&fep->tmreg_lock, flags);
317 
318 	/* 1ns counter */
319 	writel(inc << FEC_T_INC_OFFSET, fep->hwp + FEC_ATIME_INC);
320 
321 	/* use 31-bit timer counter */
322 	writel(FEC_COUNTER_PERIOD, fep->hwp + FEC_ATIME_EVT_PERIOD);
323 
324 	writel(FEC_T_CTRL_ENABLE | FEC_T_CTRL_PERIOD_RST,
325 		fep->hwp + FEC_ATIME_CTRL);
326 
327 	memset(&fep->cc, 0, sizeof(fep->cc));
328 	fep->cc.read = fec_ptp_read;
329 	fep->cc.mask = CLOCKSOURCE_MASK(31);
330 	fep->cc.shift = 31;
331 	fep->cc.mult = FEC_CC_MULT;
332 
333 	/* reset the ns time counter */
334 	timecounter_init(&fep->tc, &fep->cc, 0);
335 
336 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
337 }
338 
339 /**
340  * fec_ptp_adjfine - adjust ptp cycle frequency
341  * @ptp: the ptp clock structure
342  * @scaled_ppm: scaled parts per million adjustment from base
343  *
344  * Adjust the frequency of the ptp cycle counter by the
345  * indicated amount from the base frequency.
346  *
347  * Scaled parts per million is ppm with a 16-bit binary fractional field.
348  *
349  * Because ENET hardware frequency adjust is complex,
350  * using software method to do that.
351  */
352 static int fec_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
353 {
354 	s32 ppb = scaled_ppm_to_ppb(scaled_ppm);
355 	unsigned long flags;
356 	int neg_adj = 0;
357 	u32 i, tmp;
358 	u32 corr_inc, corr_period;
359 	u32 corr_ns;
360 	u64 lhs, rhs;
361 
362 	struct fec_enet_private *fep =
363 	    container_of(ptp, struct fec_enet_private, ptp_caps);
364 
365 	if (ppb == 0)
366 		return 0;
367 
368 	if (ppb < 0) {
369 		ppb = -ppb;
370 		neg_adj = 1;
371 	}
372 
373 	/* In theory, corr_inc/corr_period = ppb/NSEC_PER_SEC;
374 	 * Try to find the corr_inc  between 1 to fep->ptp_inc to
375 	 * meet adjustment requirement.
376 	 */
377 	lhs = NSEC_PER_SEC;
378 	rhs = (u64)ppb * (u64)fep->ptp_inc;
379 	for (i = 1; i <= fep->ptp_inc; i++) {
380 		if (lhs >= rhs) {
381 			corr_inc = i;
382 			corr_period = div_u64(lhs, rhs);
383 			break;
384 		}
385 		lhs += NSEC_PER_SEC;
386 	}
387 	/* Not found? Set it to high value - double speed
388 	 * correct in every clock step.
389 	 */
390 	if (i > fep->ptp_inc) {
391 		corr_inc = fep->ptp_inc;
392 		corr_period = 1;
393 	}
394 
395 	if (neg_adj)
396 		corr_ns = fep->ptp_inc - corr_inc;
397 	else
398 		corr_ns = fep->ptp_inc + corr_inc;
399 
400 	spin_lock_irqsave(&fep->tmreg_lock, flags);
401 
402 	tmp = readl(fep->hwp + FEC_ATIME_INC) & FEC_T_INC_MASK;
403 	tmp |= corr_ns << FEC_T_INC_CORR_OFFSET;
404 	writel(tmp, fep->hwp + FEC_ATIME_INC);
405 	corr_period = corr_period > 1 ? corr_period - 1 : corr_period;
406 	writel(corr_period, fep->hwp + FEC_ATIME_CORR);
407 	/* dummy read to update the timer. */
408 	timecounter_read(&fep->tc);
409 
410 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
411 
412 	return 0;
413 }
414 
415 /**
416  * fec_ptp_adjtime
417  * @ptp: the ptp clock structure
418  * @delta: offset to adjust the cycle counter by
419  *
420  * adjust the timer by resetting the timecounter structure.
421  */
422 static int fec_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
423 {
424 	struct fec_enet_private *fep =
425 	    container_of(ptp, struct fec_enet_private, ptp_caps);
426 	unsigned long flags;
427 
428 	spin_lock_irqsave(&fep->tmreg_lock, flags);
429 	timecounter_adjtime(&fep->tc, delta);
430 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
431 
432 	return 0;
433 }
434 
435 /**
436  * fec_ptp_gettime
437  * @ptp: the ptp clock structure
438  * @ts: timespec structure to hold the current time value
439  *
440  * read the timecounter and return the correct value on ns,
441  * after converting it into a struct timespec.
442  */
443 static int fec_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
444 {
445 	struct fec_enet_private *fep =
446 	    container_of(ptp, struct fec_enet_private, ptp_caps);
447 	u64 ns;
448 	unsigned long flags;
449 
450 	mutex_lock(&fep->ptp_clk_mutex);
451 	/* Check the ptp clock */
452 	if (!fep->ptp_clk_on) {
453 		mutex_unlock(&fep->ptp_clk_mutex);
454 		return -EINVAL;
455 	}
456 	spin_lock_irqsave(&fep->tmreg_lock, flags);
457 	ns = timecounter_read(&fep->tc);
458 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
459 	mutex_unlock(&fep->ptp_clk_mutex);
460 
461 	*ts = ns_to_timespec64(ns);
462 
463 	return 0;
464 }
465 
466 /**
467  * fec_ptp_settime
468  * @ptp: the ptp clock structure
469  * @ts: the timespec containing the new time for the cycle counter
470  *
471  * reset the timecounter to use a new base value instead of the kernel
472  * wall timer value.
473  */
474 static int fec_ptp_settime(struct ptp_clock_info *ptp,
475 			   const struct timespec64 *ts)
476 {
477 	struct fec_enet_private *fep =
478 	    container_of(ptp, struct fec_enet_private, ptp_caps);
479 
480 	u64 ns;
481 	unsigned long flags;
482 	u32 counter;
483 
484 	mutex_lock(&fep->ptp_clk_mutex);
485 	/* Check the ptp clock */
486 	if (!fep->ptp_clk_on) {
487 		mutex_unlock(&fep->ptp_clk_mutex);
488 		return -EINVAL;
489 	}
490 
491 	ns = timespec64_to_ns(ts);
492 	/* Get the timer value based on timestamp.
493 	 * Update the counter with the masked value.
494 	 */
495 	counter = ns & fep->cc.mask;
496 
497 	spin_lock_irqsave(&fep->tmreg_lock, flags);
498 	writel(counter, fep->hwp + FEC_ATIME);
499 	timecounter_init(&fep->tc, &fep->cc, ns);
500 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
501 	mutex_unlock(&fep->ptp_clk_mutex);
502 	return 0;
503 }
504 
505 static int fec_ptp_pps_disable(struct fec_enet_private *fep, uint channel)
506 {
507 	unsigned long flags;
508 
509 	spin_lock_irqsave(&fep->tmreg_lock, flags);
510 	writel(0, fep->hwp + FEC_TCSR(channel));
511 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
512 
513 	return 0;
514 }
515 
516 /**
517  * fec_ptp_enable
518  * @ptp: the ptp clock structure
519  * @rq: the requested feature to change
520  * @on: whether to enable or disable the feature
521  *
522  */
523 static int fec_ptp_enable(struct ptp_clock_info *ptp,
524 			  struct ptp_clock_request *rq, int on)
525 {
526 	struct fec_enet_private *fep =
527 	    container_of(ptp, struct fec_enet_private, ptp_caps);
528 	ktime_t timeout;
529 	struct timespec64 start_time, period;
530 	u64 curr_time, delta, period_ns;
531 	unsigned long flags;
532 	int ret = 0;
533 
534 	if (rq->type == PTP_CLK_REQ_PPS) {
535 		ret = fec_ptp_enable_pps(fep, on);
536 
537 		return ret;
538 	} else if (rq->type == PTP_CLK_REQ_PEROUT) {
539 		/* Reject requests with unsupported flags */
540 		if (rq->perout.flags)
541 			return -EOPNOTSUPP;
542 
543 		if (rq->perout.index != DEFAULT_PPS_CHANNEL)
544 			return -EOPNOTSUPP;
545 
546 		fep->pps_channel = DEFAULT_PPS_CHANNEL;
547 		period.tv_sec = rq->perout.period.sec;
548 		period.tv_nsec = rq->perout.period.nsec;
549 		period_ns = timespec64_to_ns(&period);
550 
551 		/* FEC PTP timer only has 31 bits, so if the period exceed
552 		 * 4s is not supported.
553 		 */
554 		if (period_ns > FEC_PTP_MAX_NSEC_PERIOD) {
555 			dev_err(&fep->pdev->dev, "The period must equal to or less than 4s!\n");
556 			return -EOPNOTSUPP;
557 		}
558 
559 		fep->reload_period = div_u64(period_ns, 2);
560 		if (on && fep->reload_period) {
561 			/* Convert 1588 timestamp to ns*/
562 			start_time.tv_sec = rq->perout.start.sec;
563 			start_time.tv_nsec = rq->perout.start.nsec;
564 			fep->perout_stime = timespec64_to_ns(&start_time);
565 
566 			mutex_lock(&fep->ptp_clk_mutex);
567 			if (!fep->ptp_clk_on) {
568 				dev_err(&fep->pdev->dev, "Error: PTP clock is closed!\n");
569 				mutex_unlock(&fep->ptp_clk_mutex);
570 				return -EOPNOTSUPP;
571 			}
572 			spin_lock_irqsave(&fep->tmreg_lock, flags);
573 			/* Read current timestamp */
574 			curr_time = timecounter_read(&fep->tc);
575 			spin_unlock_irqrestore(&fep->tmreg_lock, flags);
576 			mutex_unlock(&fep->ptp_clk_mutex);
577 
578 			/* Calculate time difference */
579 			delta = fep->perout_stime - curr_time;
580 
581 			if (fep->perout_stime <= curr_time) {
582 				dev_err(&fep->pdev->dev, "Start time must larger than current time!\n");
583 				return -EINVAL;
584 			}
585 
586 			/* Because the timer counter of FEC only has 31-bits, correspondingly,
587 			 * the time comparison register FEC_TCCR also only low 31 bits can be
588 			 * set. If the start time of pps signal exceeds current time more than
589 			 * 0x80000000 ns, a software timer is used and the timer expires about
590 			 * 1 second before the start time to be able to set FEC_TCCR.
591 			 */
592 			if (delta > FEC_PTP_MAX_NSEC_COUNTER) {
593 				timeout = ns_to_ktime(delta - NSEC_PER_SEC);
594 				hrtimer_start(&fep->perout_timer, timeout, HRTIMER_MODE_REL);
595 			} else {
596 				return fec_ptp_pps_perout(fep);
597 			}
598 		} else {
599 			fec_ptp_pps_disable(fep, fep->pps_channel);
600 		}
601 
602 		return 0;
603 	} else {
604 		return -EOPNOTSUPP;
605 	}
606 }
607 
608 int fec_ptp_set(struct net_device *ndev, struct kernel_hwtstamp_config *config,
609 		struct netlink_ext_ack *extack)
610 {
611 	struct fec_enet_private *fep = netdev_priv(ndev);
612 
613 	switch (config->tx_type) {
614 	case HWTSTAMP_TX_OFF:
615 		fep->hwts_tx_en = 0;
616 		break;
617 	case HWTSTAMP_TX_ON:
618 		fep->hwts_tx_en = 1;
619 		break;
620 	default:
621 		return -ERANGE;
622 	}
623 
624 	switch (config->rx_filter) {
625 	case HWTSTAMP_FILTER_NONE:
626 		fep->hwts_rx_en = 0;
627 		break;
628 
629 	default:
630 		fep->hwts_rx_en = 1;
631 		config->rx_filter = HWTSTAMP_FILTER_ALL;
632 		break;
633 	}
634 
635 	return 0;
636 }
637 
638 void fec_ptp_get(struct net_device *ndev, struct kernel_hwtstamp_config *config)
639 {
640 	struct fec_enet_private *fep = netdev_priv(ndev);
641 
642 	config->flags = 0;
643 	config->tx_type = fep->hwts_tx_en ? HWTSTAMP_TX_ON : HWTSTAMP_TX_OFF;
644 	config->rx_filter = (fep->hwts_rx_en ?
645 			     HWTSTAMP_FILTER_ALL : HWTSTAMP_FILTER_NONE);
646 }
647 
648 /*
649  * fec_time_keep - call timecounter_read every second to avoid timer overrun
650  *                 because ENET just support 32bit counter, will timeout in 4s
651  */
652 static void fec_time_keep(struct work_struct *work)
653 {
654 	struct delayed_work *dwork = to_delayed_work(work);
655 	struct fec_enet_private *fep = container_of(dwork, struct fec_enet_private, time_keep);
656 	unsigned long flags;
657 
658 	mutex_lock(&fep->ptp_clk_mutex);
659 	if (fep->ptp_clk_on) {
660 		spin_lock_irqsave(&fep->tmreg_lock, flags);
661 		timecounter_read(&fep->tc);
662 		spin_unlock_irqrestore(&fep->tmreg_lock, flags);
663 	}
664 	mutex_unlock(&fep->ptp_clk_mutex);
665 
666 	schedule_delayed_work(&fep->time_keep, HZ);
667 }
668 
669 /* This function checks the pps event and reloads the timer compare counter. */
670 static irqreturn_t fec_pps_interrupt(int irq, void *dev_id)
671 {
672 	struct net_device *ndev = dev_id;
673 	struct fec_enet_private *fep = netdev_priv(ndev);
674 	u32 val;
675 	u8 channel = fep->pps_channel;
676 	struct ptp_clock_event event;
677 
678 	val = readl(fep->hwp + FEC_TCSR(channel));
679 	if (val & FEC_T_TF_MASK) {
680 		/* Write the next next compare(not the next according the spec)
681 		 * value to the register
682 		 */
683 		writel(fep->next_counter, fep->hwp + FEC_TCCR(channel));
684 		do {
685 			writel(val, fep->hwp + FEC_TCSR(channel));
686 		} while (readl(fep->hwp + FEC_TCSR(channel)) & FEC_T_TF_MASK);
687 
688 		/* Update the counter; */
689 		fep->next_counter = (fep->next_counter + fep->reload_period) &
690 				fep->cc.mask;
691 
692 		event.type = PTP_CLOCK_PPS;
693 		ptp_clock_event(fep->ptp_clock, &event);
694 		return IRQ_HANDLED;
695 	}
696 
697 	return IRQ_NONE;
698 }
699 
700 /**
701  * fec_ptp_init
702  * @pdev: The FEC network adapter
703  * @irq_idx: the interrupt index
704  *
705  * This function performs the required steps for enabling ptp
706  * support. If ptp support has already been loaded it simply calls the
707  * cyclecounter init routine and exits.
708  */
709 
710 void fec_ptp_init(struct platform_device *pdev, int irq_idx)
711 {
712 	struct net_device *ndev = platform_get_drvdata(pdev);
713 	struct fec_enet_private *fep = netdev_priv(ndev);
714 	int irq;
715 	int ret;
716 
717 	fep->ptp_caps.owner = THIS_MODULE;
718 	strscpy(fep->ptp_caps.name, "fec ptp", sizeof(fep->ptp_caps.name));
719 
720 	fep->ptp_caps.max_adj = 250000000;
721 	fep->ptp_caps.n_alarm = 0;
722 	fep->ptp_caps.n_ext_ts = 0;
723 	fep->ptp_caps.n_per_out = 1;
724 	fep->ptp_caps.n_pins = 0;
725 	fep->ptp_caps.pps = 1;
726 	fep->ptp_caps.adjfine = fec_ptp_adjfine;
727 	fep->ptp_caps.adjtime = fec_ptp_adjtime;
728 	fep->ptp_caps.gettime64 = fec_ptp_gettime;
729 	fep->ptp_caps.settime64 = fec_ptp_settime;
730 	fep->ptp_caps.enable = fec_ptp_enable;
731 
732 	fep->cycle_speed = clk_get_rate(fep->clk_ptp);
733 	if (!fep->cycle_speed) {
734 		fep->cycle_speed = NSEC_PER_SEC;
735 		dev_err(&fep->pdev->dev, "clk_ptp clock rate is zero\n");
736 	}
737 	fep->ptp_inc = NSEC_PER_SEC / fep->cycle_speed;
738 
739 	spin_lock_init(&fep->tmreg_lock);
740 
741 	fec_ptp_start_cyclecounter(ndev);
742 
743 	INIT_DELAYED_WORK(&fep->time_keep, fec_time_keep);
744 
745 	hrtimer_init(&fep->perout_timer, CLOCK_REALTIME, HRTIMER_MODE_REL);
746 	fep->perout_timer.function = fec_ptp_pps_perout_handler;
747 
748 	irq = platform_get_irq_byname_optional(pdev, "pps");
749 	if (irq < 0)
750 		irq = platform_get_irq_optional(pdev, irq_idx);
751 	/* Failure to get an irq is not fatal,
752 	 * only the PTP_CLOCK_PPS clock events should stop
753 	 */
754 	if (irq >= 0) {
755 		ret = devm_request_irq(&pdev->dev, irq, fec_pps_interrupt,
756 				       0, pdev->name, ndev);
757 		if (ret < 0)
758 			dev_warn(&pdev->dev, "request for pps irq failed(%d)\n",
759 				 ret);
760 	}
761 
762 	fep->ptp_clock = ptp_clock_register(&fep->ptp_caps, &pdev->dev);
763 	if (IS_ERR(fep->ptp_clock)) {
764 		fep->ptp_clock = NULL;
765 		dev_err(&pdev->dev, "ptp_clock_register failed\n");
766 	}
767 
768 	schedule_delayed_work(&fep->time_keep, HZ);
769 }
770 
771 void fec_ptp_stop(struct platform_device *pdev)
772 {
773 	struct net_device *ndev = platform_get_drvdata(pdev);
774 	struct fec_enet_private *fep = netdev_priv(ndev);
775 
776 	cancel_delayed_work_sync(&fep->time_keep);
777 	hrtimer_cancel(&fep->perout_timer);
778 	if (fep->ptp_clock)
779 		ptp_clock_unregister(fep->ptp_clock);
780 }
781