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 #define FEC_PTP_MAX_NSEC_PERIOD		4000000000ULL
92 #define FEC_PTP_MAX_NSEC_COUNTER	0x80000000ULL
93 
94 /**
95  * fec_ptp_enable_pps
96  * @fep: the fec_enet_private structure handle
97  * @enable: enable the channel pps output
98  *
99  * This function enble the PPS ouput on the timer channel.
100  */
101 static int fec_ptp_enable_pps(struct fec_enet_private *fep, uint enable)
102 {
103 	unsigned long flags;
104 	u32 val, tempval;
105 	struct timespec64 ts;
106 	u64 ns;
107 
108 	if (fep->pps_enable == enable)
109 		return 0;
110 
111 	fep->pps_channel = DEFAULT_PPS_CHANNEL;
112 	fep->reload_period = PPS_OUPUT_RELOAD_PERIOD;
113 
114 	spin_lock_irqsave(&fep->tmreg_lock, flags);
115 
116 	if (enable) {
117 		/* clear capture or output compare interrupt status if have.
118 		 */
119 		writel(FEC_T_TF_MASK, fep->hwp + FEC_TCSR(fep->pps_channel));
120 
121 		/* It is recommended to double check the TMODE field in the
122 		 * TCSR register to be cleared before the first compare counter
123 		 * is written into TCCR register. Just add a double check.
124 		 */
125 		val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
126 		do {
127 			val &= ~(FEC_T_TMODE_MASK);
128 			writel(val, fep->hwp + FEC_TCSR(fep->pps_channel));
129 			val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
130 		} while (val & FEC_T_TMODE_MASK);
131 
132 		/* Dummy read counter to update the counter */
133 		timecounter_read(&fep->tc);
134 		/* We want to find the first compare event in the next
135 		 * second point. So we need to know what the ptp time
136 		 * is now and how many nanoseconds is ahead to get next second.
137 		 * The remaining nanosecond ahead before the next second would be
138 		 * NSEC_PER_SEC - ts.tv_nsec. Add the remaining nanoseconds
139 		 * to current timer would be next second.
140 		 */
141 		tempval = fep->cc.read(&fep->cc);
142 		/* Convert the ptp local counter to 1588 timestamp */
143 		ns = timecounter_cyc2time(&fep->tc, tempval);
144 		ts = ns_to_timespec64(ns);
145 
146 		/* The tempval is  less than 3 seconds, and  so val is less than
147 		 * 4 seconds. No overflow for 32bit calculation.
148 		 */
149 		val = NSEC_PER_SEC - (u32)ts.tv_nsec + tempval;
150 
151 		/* Need to consider the situation that the current time is
152 		 * very close to the second point, which means NSEC_PER_SEC
153 		 * - ts.tv_nsec is close to be zero(For example 20ns); Since the timer
154 		 * is still running when we calculate the first compare event, it is
155 		 * possible that the remaining nanoseonds run out before the compare
156 		 * counter is calculated and written into TCCR register. To avoid
157 		 * this possibility, we will set the compare event to be the next
158 		 * of next second. The current setting is 31-bit timer and wrap
159 		 * around over 2 seconds. So it is okay to set the next of next
160 		 * seond for the timer.
161 		 */
162 		val += NSEC_PER_SEC;
163 
164 		/* We add (2 * NSEC_PER_SEC - (u32)ts.tv_nsec) to current
165 		 * ptp counter, which maybe cause 32-bit wrap. Since the
166 		 * (NSEC_PER_SEC - (u32)ts.tv_nsec) is less than 2 second.
167 		 * We can ensure the wrap will not cause issue. If the offset
168 		 * is bigger than fep->cc.mask would be a error.
169 		 */
170 		val &= fep->cc.mask;
171 		writel(val, fep->hwp + FEC_TCCR(fep->pps_channel));
172 
173 		/* Calculate the second the compare event timestamp */
174 		fep->next_counter = (val + fep->reload_period) & fep->cc.mask;
175 
176 		/* * Enable compare event when overflow */
177 		val = readl(fep->hwp + FEC_ATIME_CTRL);
178 		val |= FEC_T_CTRL_PINPER;
179 		writel(val, fep->hwp + FEC_ATIME_CTRL);
180 
181 		/* Compare channel setting. */
182 		val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
183 		val |= (1 << FEC_T_TF_OFFSET | 1 << FEC_T_TIE_OFFSET);
184 		val &= ~(1 << FEC_T_TDRE_OFFSET);
185 		val &= ~(FEC_T_TMODE_MASK);
186 		val |= (FEC_HIGH_PULSE << FEC_T_TMODE_OFFSET);
187 		writel(val, fep->hwp + FEC_TCSR(fep->pps_channel));
188 
189 		/* Write the second compare event timestamp and calculate
190 		 * the third timestamp. Refer the TCCR register detail in the spec.
191 		 */
192 		writel(fep->next_counter, fep->hwp + FEC_TCCR(fep->pps_channel));
193 		fep->next_counter = (fep->next_counter + fep->reload_period) & fep->cc.mask;
194 	} else {
195 		writel(0, fep->hwp + FEC_TCSR(fep->pps_channel));
196 	}
197 
198 	fep->pps_enable = enable;
199 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
200 
201 	return 0;
202 }
203 
204 static int fec_ptp_pps_perout(struct fec_enet_private *fep)
205 {
206 	u32 compare_val, ptp_hc, temp_val;
207 	u64 curr_time;
208 	unsigned long flags;
209 
210 	spin_lock_irqsave(&fep->tmreg_lock, flags);
211 
212 	/* Update time counter */
213 	timecounter_read(&fep->tc);
214 
215 	/* Get the current ptp hardware time counter */
216 	temp_val = readl(fep->hwp + FEC_ATIME_CTRL);
217 	temp_val |= FEC_T_CTRL_CAPTURE;
218 	writel(temp_val, fep->hwp + FEC_ATIME_CTRL);
219 	if (fep->quirks & FEC_QUIRK_BUG_CAPTURE)
220 		udelay(1);
221 
222 	ptp_hc = readl(fep->hwp + FEC_ATIME);
223 
224 	/* Convert the ptp local counter to 1588 timestamp */
225 	curr_time = timecounter_cyc2time(&fep->tc, ptp_hc);
226 
227 	/* If the pps start time less than current time add 100ms, just return.
228 	 * Because the software might not able to set the comparison time into
229 	 * the FEC_TCCR register in time and missed the start time.
230 	 */
231 	if (fep->perout_stime < curr_time + 100 * NSEC_PER_MSEC) {
232 		dev_err(&fep->pdev->dev, "Current time is too close to the start time!\n");
233 		spin_unlock_irqrestore(&fep->tmreg_lock, flags);
234 		return -1;
235 	}
236 
237 	compare_val = fep->perout_stime - curr_time + ptp_hc;
238 	compare_val &= fep->cc.mask;
239 
240 	writel(compare_val, fep->hwp + FEC_TCCR(fep->pps_channel));
241 	fep->next_counter = (compare_val + fep->reload_period) & fep->cc.mask;
242 
243 	/* Enable compare event when overflow */
244 	temp_val = readl(fep->hwp + FEC_ATIME_CTRL);
245 	temp_val |= FEC_T_CTRL_PINPER;
246 	writel(temp_val, fep->hwp + FEC_ATIME_CTRL);
247 
248 	/* Compare channel setting. */
249 	temp_val = readl(fep->hwp + FEC_TCSR(fep->pps_channel));
250 	temp_val |= (1 << FEC_T_TF_OFFSET | 1 << FEC_T_TIE_OFFSET);
251 	temp_val &= ~(1 << FEC_T_TDRE_OFFSET);
252 	temp_val &= ~(FEC_T_TMODE_MASK);
253 	temp_val |= (FEC_TMODE_TOGGLE << FEC_T_TMODE_OFFSET);
254 	writel(temp_val, fep->hwp + FEC_TCSR(fep->pps_channel));
255 
256 	/* Write the second compare event timestamp and calculate
257 	 * the third timestamp. Refer the TCCR register detail in the spec.
258 	 */
259 	writel(fep->next_counter, fep->hwp + FEC_TCCR(fep->pps_channel));
260 	fep->next_counter = (fep->next_counter + fep->reload_period) & fep->cc.mask;
261 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
262 
263 	return 0;
264 }
265 
266 static enum hrtimer_restart fec_ptp_pps_perout_handler(struct hrtimer *timer)
267 {
268 	struct fec_enet_private *fep = container_of(timer,
269 					struct fec_enet_private, perout_timer);
270 
271 	fec_ptp_pps_perout(fep);
272 
273 	return HRTIMER_NORESTART;
274 }
275 
276 /**
277  * fec_ptp_read - read raw cycle counter (to be used by time counter)
278  * @cc: the cyclecounter structure
279  *
280  * this function reads the cyclecounter registers and is called by the
281  * cyclecounter structure used to construct a ns counter from the
282  * arbitrary fixed point registers
283  */
284 static u64 fec_ptp_read(const struct cyclecounter *cc)
285 {
286 	struct fec_enet_private *fep =
287 		container_of(cc, struct fec_enet_private, cc);
288 	u32 tempval;
289 
290 	tempval = readl(fep->hwp + FEC_ATIME_CTRL);
291 	tempval |= FEC_T_CTRL_CAPTURE;
292 	writel(tempval, fep->hwp + FEC_ATIME_CTRL);
293 
294 	if (fep->quirks & FEC_QUIRK_BUG_CAPTURE)
295 		udelay(1);
296 
297 	return readl(fep->hwp + FEC_ATIME);
298 }
299 
300 /**
301  * fec_ptp_start_cyclecounter - create the cycle counter from hw
302  * @ndev: network device
303  *
304  * this function initializes the timecounter and cyclecounter
305  * structures for use in generated a ns counter from the arbitrary
306  * fixed point cycles registers in the hardware.
307  */
308 void fec_ptp_start_cyclecounter(struct net_device *ndev)
309 {
310 	struct fec_enet_private *fep = netdev_priv(ndev);
311 	unsigned long flags;
312 	int inc;
313 
314 	inc = 1000000000 / fep->cycle_speed;
315 
316 	/* grab the ptp lock */
317 	spin_lock_irqsave(&fep->tmreg_lock, flags);
318 
319 	/* 1ns counter */
320 	writel(inc << FEC_T_INC_OFFSET, fep->hwp + FEC_ATIME_INC);
321 
322 	/* use 31-bit timer counter */
323 	writel(FEC_COUNTER_PERIOD, fep->hwp + FEC_ATIME_EVT_PERIOD);
324 
325 	writel(FEC_T_CTRL_ENABLE | FEC_T_CTRL_PERIOD_RST,
326 		fep->hwp + FEC_ATIME_CTRL);
327 
328 	memset(&fep->cc, 0, sizeof(fep->cc));
329 	fep->cc.read = fec_ptp_read;
330 	fep->cc.mask = CLOCKSOURCE_MASK(31);
331 	fep->cc.shift = 31;
332 	fep->cc.mult = FEC_CC_MULT;
333 
334 	/* reset the ns time counter */
335 	timecounter_init(&fep->tc, &fep->cc, 0);
336 
337 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
338 }
339 
340 /**
341  * fec_ptp_adjfreq - adjust ptp cycle frequency
342  * @ptp: the ptp clock structure
343  * @ppb: parts per billion adjustment from base
344  *
345  * Adjust the frequency of the ptp cycle counter by the
346  * indicated ppb from the base frequency.
347  *
348  * Because ENET hardware frequency adjust is complex,
349  * using software method to do that.
350  */
351 static int fec_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
352 {
353 	unsigned long flags;
354 	int neg_adj = 0;
355 	u32 i, tmp;
356 	u32 corr_inc, corr_period;
357 	u32 corr_ns;
358 	u64 lhs, rhs;
359 
360 	struct fec_enet_private *fep =
361 	    container_of(ptp, struct fec_enet_private, ptp_caps);
362 
363 	if (ppb == 0)
364 		return 0;
365 
366 	if (ppb < 0) {
367 		ppb = -ppb;
368 		neg_adj = 1;
369 	}
370 
371 	/* In theory, corr_inc/corr_period = ppb/NSEC_PER_SEC;
372 	 * Try to find the corr_inc  between 1 to fep->ptp_inc to
373 	 * meet adjustment requirement.
374 	 */
375 	lhs = NSEC_PER_SEC;
376 	rhs = (u64)ppb * (u64)fep->ptp_inc;
377 	for (i = 1; i <= fep->ptp_inc; i++) {
378 		if (lhs >= rhs) {
379 			corr_inc = i;
380 			corr_period = div_u64(lhs, rhs);
381 			break;
382 		}
383 		lhs += NSEC_PER_SEC;
384 	}
385 	/* Not found? Set it to high value - double speed
386 	 * correct in every clock step.
387 	 */
388 	if (i > fep->ptp_inc) {
389 		corr_inc = fep->ptp_inc;
390 		corr_period = 1;
391 	}
392 
393 	if (neg_adj)
394 		corr_ns = fep->ptp_inc - corr_inc;
395 	else
396 		corr_ns = fep->ptp_inc + corr_inc;
397 
398 	spin_lock_irqsave(&fep->tmreg_lock, flags);
399 
400 	tmp = readl(fep->hwp + FEC_ATIME_INC) & FEC_T_INC_MASK;
401 	tmp |= corr_ns << FEC_T_INC_CORR_OFFSET;
402 	writel(tmp, fep->hwp + FEC_ATIME_INC);
403 	corr_period = corr_period > 1 ? corr_period - 1 : corr_period;
404 	writel(corr_period, fep->hwp + FEC_ATIME_CORR);
405 	/* dummy read to update the timer. */
406 	timecounter_read(&fep->tc);
407 
408 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
409 
410 	return 0;
411 }
412 
413 /**
414  * fec_ptp_adjtime
415  * @ptp: the ptp clock structure
416  * @delta: offset to adjust the cycle counter by
417  *
418  * adjust the timer by resetting the timecounter structure.
419  */
420 static int fec_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
421 {
422 	struct fec_enet_private *fep =
423 	    container_of(ptp, struct fec_enet_private, ptp_caps);
424 	unsigned long flags;
425 
426 	spin_lock_irqsave(&fep->tmreg_lock, flags);
427 	timecounter_adjtime(&fep->tc, delta);
428 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
429 
430 	return 0;
431 }
432 
433 /**
434  * fec_ptp_gettime
435  * @ptp: the ptp clock structure
436  * @ts: timespec structure to hold the current time value
437  *
438  * read the timecounter and return the correct value on ns,
439  * after converting it into a struct timespec.
440  */
441 static int fec_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
442 {
443 	struct fec_enet_private *adapter =
444 	    container_of(ptp, struct fec_enet_private, ptp_caps);
445 	u64 ns;
446 	unsigned long flags;
447 
448 	mutex_lock(&adapter->ptp_clk_mutex);
449 	/* Check the ptp clock */
450 	if (!adapter->ptp_clk_on) {
451 		mutex_unlock(&adapter->ptp_clk_mutex);
452 		return -EINVAL;
453 	}
454 	spin_lock_irqsave(&adapter->tmreg_lock, flags);
455 	ns = timecounter_read(&adapter->tc);
456 	spin_unlock_irqrestore(&adapter->tmreg_lock, flags);
457 	mutex_unlock(&adapter->ptp_clk_mutex);
458 
459 	*ts = ns_to_timespec64(ns);
460 
461 	return 0;
462 }
463 
464 /**
465  * fec_ptp_settime
466  * @ptp: the ptp clock structure
467  * @ts: the timespec containing the new time for the cycle counter
468  *
469  * reset the timecounter to use a new base value instead of the kernel
470  * wall timer value.
471  */
472 static int fec_ptp_settime(struct ptp_clock_info *ptp,
473 			   const struct timespec64 *ts)
474 {
475 	struct fec_enet_private *fep =
476 	    container_of(ptp, struct fec_enet_private, ptp_caps);
477 
478 	u64 ns;
479 	unsigned long flags;
480 	u32 counter;
481 
482 	mutex_lock(&fep->ptp_clk_mutex);
483 	/* Check the ptp clock */
484 	if (!fep->ptp_clk_on) {
485 		mutex_unlock(&fep->ptp_clk_mutex);
486 		return -EINVAL;
487 	}
488 
489 	ns = timespec64_to_ns(ts);
490 	/* Get the timer value based on timestamp.
491 	 * Update the counter with the masked value.
492 	 */
493 	counter = ns & fep->cc.mask;
494 
495 	spin_lock_irqsave(&fep->tmreg_lock, flags);
496 	writel(counter, fep->hwp + FEC_ATIME);
497 	timecounter_init(&fep->tc, &fep->cc, ns);
498 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
499 	mutex_unlock(&fep->ptp_clk_mutex);
500 	return 0;
501 }
502 
503 static int fec_ptp_pps_disable(struct fec_enet_private *fep, uint channel)
504 {
505 	unsigned long flags;
506 
507 	spin_lock_irqsave(&fep->tmreg_lock, flags);
508 	writel(0, fep->hwp + FEC_TCSR(channel));
509 	spin_unlock_irqrestore(&fep->tmreg_lock, flags);
510 
511 	return 0;
512 }
513 
514 /**
515  * fec_ptp_enable
516  * @ptp: the ptp clock structure
517  * @rq: the requested feature to change
518  * @on: whether to enable or disable the feature
519  *
520  */
521 static int fec_ptp_enable(struct ptp_clock_info *ptp,
522 			  struct ptp_clock_request *rq, int on)
523 {
524 	struct fec_enet_private *fep =
525 	    container_of(ptp, struct fec_enet_private, ptp_caps);
526 	ktime_t timeout;
527 	struct timespec64 start_time, period;
528 	u64 curr_time, delta, period_ns;
529 	unsigned long flags;
530 	int ret = 0;
531 
532 	if (rq->type == PTP_CLK_REQ_PPS) {
533 		ret = fec_ptp_enable_pps(fep, on);
534 
535 		return ret;
536 	} else if (rq->type == PTP_CLK_REQ_PEROUT) {
537 		/* Reject requests with unsupported flags */
538 		if (rq->perout.flags)
539 			return -EOPNOTSUPP;
540 
541 		if (rq->perout.index != DEFAULT_PPS_CHANNEL)
542 			return -EOPNOTSUPP;
543 
544 		fep->pps_channel = DEFAULT_PPS_CHANNEL;
545 		period.tv_sec = rq->perout.period.sec;
546 		period.tv_nsec = rq->perout.period.nsec;
547 		period_ns = timespec64_to_ns(&period);
548 
549 		/* FEC PTP timer only has 31 bits, so if the period exceed
550 		 * 4s is not supported.
551 		 */
552 		if (period_ns > FEC_PTP_MAX_NSEC_PERIOD) {
553 			dev_err(&fep->pdev->dev, "The period must equal to or less than 4s!\n");
554 			return -EOPNOTSUPP;
555 		}
556 
557 		fep->reload_period = div_u64(period_ns, 2);
558 		if (on && fep->reload_period) {
559 			/* Convert 1588 timestamp to ns*/
560 			start_time.tv_sec = rq->perout.start.sec;
561 			start_time.tv_nsec = rq->perout.start.nsec;
562 			fep->perout_stime = timespec64_to_ns(&start_time);
563 
564 			mutex_lock(&fep->ptp_clk_mutex);
565 			if (!fep->ptp_clk_on) {
566 				dev_err(&fep->pdev->dev, "Error: PTP clock is closed!\n");
567 				mutex_unlock(&fep->ptp_clk_mutex);
568 				return -EOPNOTSUPP;
569 			}
570 			spin_lock_irqsave(&fep->tmreg_lock, flags);
571 			/* Read current timestamp */
572 			curr_time = timecounter_read(&fep->tc);
573 			spin_unlock_irqrestore(&fep->tmreg_lock, flags);
574 			mutex_unlock(&fep->ptp_clk_mutex);
575 
576 			/* Calculate time difference */
577 			delta = fep->perout_stime - curr_time;
578 
579 			if (fep->perout_stime <= curr_time) {
580 				dev_err(&fep->pdev->dev, "Start time must larger than current time!\n");
581 				return -EINVAL;
582 			}
583 
584 			/* Because the timer counter of FEC only has 31-bits, correspondingly,
585 			 * the time comparison register FEC_TCCR also only low 31 bits can be
586 			 * set. If the start time of pps signal exceeds current time more than
587 			 * 0x80000000 ns, a software timer is used and the timer expires about
588 			 * 1 second before the start time to be able to set FEC_TCCR.
589 			 */
590 			if (delta > FEC_PTP_MAX_NSEC_COUNTER) {
591 				timeout = ns_to_ktime(delta - NSEC_PER_SEC);
592 				hrtimer_start(&fep->perout_timer, timeout, HRTIMER_MODE_REL);
593 			} else {
594 				return fec_ptp_pps_perout(fep);
595 			}
596 		} else {
597 			fec_ptp_pps_disable(fep, fep->pps_channel);
598 		}
599 
600 		return 0;
601 	} else {
602 		return -EOPNOTSUPP;
603 	}
604 }
605 
606 /**
607  * fec_ptp_disable_hwts - disable hardware time stamping
608  * @ndev: pointer to net_device
609  */
610 void fec_ptp_disable_hwts(struct net_device *ndev)
611 {
612 	struct fec_enet_private *fep = netdev_priv(ndev);
613 
614 	fep->hwts_tx_en = 0;
615 	fep->hwts_rx_en = 0;
616 }
617 
618 int fec_ptp_set(struct net_device *ndev, struct ifreq *ifr)
619 {
620 	struct fec_enet_private *fep = netdev_priv(ndev);
621 
622 	struct hwtstamp_config config;
623 
624 	if (copy_from_user(&config, ifr->ifr_data, sizeof(config)))
625 		return -EFAULT;
626 
627 	switch (config.tx_type) {
628 	case HWTSTAMP_TX_OFF:
629 		fep->hwts_tx_en = 0;
630 		break;
631 	case HWTSTAMP_TX_ON:
632 		fep->hwts_tx_en = 1;
633 		break;
634 	default:
635 		return -ERANGE;
636 	}
637 
638 	switch (config.rx_filter) {
639 	case HWTSTAMP_FILTER_NONE:
640 		fep->hwts_rx_en = 0;
641 		break;
642 
643 	default:
644 		fep->hwts_rx_en = 1;
645 		config.rx_filter = HWTSTAMP_FILTER_ALL;
646 		break;
647 	}
648 
649 	return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
650 	    -EFAULT : 0;
651 }
652 
653 int fec_ptp_get(struct net_device *ndev, struct ifreq *ifr)
654 {
655 	struct fec_enet_private *fep = netdev_priv(ndev);
656 	struct hwtstamp_config config;
657 
658 	config.flags = 0;
659 	config.tx_type = fep->hwts_tx_en ? HWTSTAMP_TX_ON : HWTSTAMP_TX_OFF;
660 	config.rx_filter = (fep->hwts_rx_en ?
661 			    HWTSTAMP_FILTER_ALL : HWTSTAMP_FILTER_NONE);
662 
663 	return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
664 		-EFAULT : 0;
665 }
666 
667 /*
668  * fec_time_keep - call timecounter_read every second to avoid timer overrun
669  *                 because ENET just support 32bit counter, will timeout in 4s
670  */
671 static void fec_time_keep(struct work_struct *work)
672 {
673 	struct delayed_work *dwork = to_delayed_work(work);
674 	struct fec_enet_private *fep = container_of(dwork, struct fec_enet_private, time_keep);
675 	unsigned long flags;
676 
677 	mutex_lock(&fep->ptp_clk_mutex);
678 	if (fep->ptp_clk_on) {
679 		spin_lock_irqsave(&fep->tmreg_lock, flags);
680 		timecounter_read(&fep->tc);
681 		spin_unlock_irqrestore(&fep->tmreg_lock, flags);
682 	}
683 	mutex_unlock(&fep->ptp_clk_mutex);
684 
685 	schedule_delayed_work(&fep->time_keep, HZ);
686 }
687 
688 /* This function checks the pps event and reloads the timer compare counter. */
689 static irqreturn_t fec_pps_interrupt(int irq, void *dev_id)
690 {
691 	struct net_device *ndev = dev_id;
692 	struct fec_enet_private *fep = netdev_priv(ndev);
693 	u32 val;
694 	u8 channel = fep->pps_channel;
695 	struct ptp_clock_event event;
696 
697 	val = readl(fep->hwp + FEC_TCSR(channel));
698 	if (val & FEC_T_TF_MASK) {
699 		/* Write the next next compare(not the next according the spec)
700 		 * value to the register
701 		 */
702 		writel(fep->next_counter, fep->hwp + FEC_TCCR(channel));
703 		do {
704 			writel(val, fep->hwp + FEC_TCSR(channel));
705 		} while (readl(fep->hwp + FEC_TCSR(channel)) & FEC_T_TF_MASK);
706 
707 		/* Update the counter; */
708 		fep->next_counter = (fep->next_counter + fep->reload_period) &
709 				fep->cc.mask;
710 
711 		event.type = PTP_CLOCK_PPS;
712 		ptp_clock_event(fep->ptp_clock, &event);
713 		return IRQ_HANDLED;
714 	}
715 
716 	return IRQ_NONE;
717 }
718 
719 /**
720  * fec_ptp_init
721  * @pdev: The FEC network adapter
722  * @irq_idx: the interrupt index
723  *
724  * This function performs the required steps for enabling ptp
725  * support. If ptp support has already been loaded it simply calls the
726  * cyclecounter init routine and exits.
727  */
728 
729 void fec_ptp_init(struct platform_device *pdev, int irq_idx)
730 {
731 	struct net_device *ndev = platform_get_drvdata(pdev);
732 	struct fec_enet_private *fep = netdev_priv(ndev);
733 	int irq;
734 	int ret;
735 
736 	fep->ptp_caps.owner = THIS_MODULE;
737 	strscpy(fep->ptp_caps.name, "fec ptp", sizeof(fep->ptp_caps.name));
738 
739 	fep->ptp_caps.max_adj = 250000000;
740 	fep->ptp_caps.n_alarm = 0;
741 	fep->ptp_caps.n_ext_ts = 0;
742 	fep->ptp_caps.n_per_out = 1;
743 	fep->ptp_caps.n_pins = 0;
744 	fep->ptp_caps.pps = 1;
745 	fep->ptp_caps.adjfreq = fec_ptp_adjfreq;
746 	fep->ptp_caps.adjtime = fec_ptp_adjtime;
747 	fep->ptp_caps.gettime64 = fec_ptp_gettime;
748 	fep->ptp_caps.settime64 = fec_ptp_settime;
749 	fep->ptp_caps.enable = fec_ptp_enable;
750 
751 	fep->cycle_speed = clk_get_rate(fep->clk_ptp);
752 	if (!fep->cycle_speed) {
753 		fep->cycle_speed = NSEC_PER_SEC;
754 		dev_err(&fep->pdev->dev, "clk_ptp clock rate is zero\n");
755 	}
756 	fep->ptp_inc = NSEC_PER_SEC / fep->cycle_speed;
757 
758 	spin_lock_init(&fep->tmreg_lock);
759 
760 	fec_ptp_start_cyclecounter(ndev);
761 
762 	INIT_DELAYED_WORK(&fep->time_keep, fec_time_keep);
763 
764 	hrtimer_init(&fep->perout_timer, CLOCK_REALTIME, HRTIMER_MODE_REL);
765 	fep->perout_timer.function = fec_ptp_pps_perout_handler;
766 
767 	irq = platform_get_irq_byname_optional(pdev, "pps");
768 	if (irq < 0)
769 		irq = platform_get_irq_optional(pdev, irq_idx);
770 	/* Failure to get an irq is not fatal,
771 	 * only the PTP_CLOCK_PPS clock events should stop
772 	 */
773 	if (irq >= 0) {
774 		ret = devm_request_irq(&pdev->dev, irq, fec_pps_interrupt,
775 				       0, pdev->name, ndev);
776 		if (ret < 0)
777 			dev_warn(&pdev->dev, "request for pps irq failed(%d)\n",
778 				 ret);
779 	}
780 
781 	fep->ptp_clock = ptp_clock_register(&fep->ptp_caps, &pdev->dev);
782 	if (IS_ERR(fep->ptp_clock)) {
783 		fep->ptp_clock = NULL;
784 		dev_err(&pdev->dev, "ptp_clock_register failed\n");
785 	}
786 
787 	schedule_delayed_work(&fep->time_keep, HZ);
788 }
789 
790 void fec_ptp_stop(struct platform_device *pdev)
791 {
792 	struct net_device *ndev = platform_get_drvdata(pdev);
793 	struct fec_enet_private *fep = netdev_priv(ndev);
794 
795 	cancel_delayed_work_sync(&fep->time_keep);
796 	hrtimer_cancel(&fep->perout_timer);
797 	if (fep->ptp_clock)
798 		ptp_clock_unregister(fep->ptp_clock);
799 }
800