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