xref: /linux/drivers/ptp/ptp_fc3.c (revision 409c38d4f156740bf3165fd6ceae4fa6425eebf4)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * PTP hardware clock driver for the FemtoClock3 family of timing and
4  * synchronization devices.
5  *
6  * Copyright (C) 2023 Integrated Device Technology, Inc., a Renesas Company.
7  */
8 #include <linux/firmware.h>
9 #include <linux/platform_device.h>
10 #include <linux/module.h>
11 #include <linux/ptp_clock_kernel.h>
12 #include <linux/delay.h>
13 #include <linux/jiffies.h>
14 #include <linux/kernel.h>
15 #include <linux/timekeeping.h>
16 #include <linux/string.h>
17 #include <linux/of.h>
18 #include <linux/bitfield.h>
19 #include <linux/mfd/rsmu.h>
20 #include <linux/mfd/idtRC38xxx_reg.h>
21 #include <asm/unaligned.h>
22 
23 #include "ptp_private.h"
24 #include "ptp_fc3.h"
25 
26 MODULE_DESCRIPTION("Driver for IDT FemtoClock3(TM) family");
27 MODULE_AUTHOR("IDT support-1588 <IDT-support-1588@lm.renesas.com>");
28 MODULE_VERSION("1.0");
29 MODULE_LICENSE("GPL");
30 
31 /*
32  * The name of the firmware file to be loaded
33  * over-rides any automatic selection
34  */
35 static char *firmware;
36 module_param(firmware, charp, 0);
37 
38 static s64 ns2counters(struct idtfc3 *idtfc3, s64 nsec, u32 *sub_ns)
39 {
40 	s64 sync;
41 	s32 rem;
42 
43 	if (likely(nsec >= 0)) {
44 		sync = div_u64_rem(nsec, idtfc3->ns_per_sync, &rem);
45 		*sub_ns = rem;
46 	} else {
47 		sync = -div_u64_rem(-nsec - 1, idtfc3->ns_per_sync, &rem) - 1;
48 		*sub_ns = idtfc3->ns_per_sync - rem - 1;
49 	}
50 
51 	return sync * idtfc3->ns_per_sync;
52 }
53 
54 static s64 tdc_meas2offset(struct idtfc3 *idtfc3, u64 meas_read)
55 {
56 	s64 coarse, fine;
57 
58 	fine = sign_extend64(FIELD_GET(FINE_MEAS_MASK, meas_read), 12);
59 	coarse = sign_extend64(FIELD_GET(COARSE_MEAS_MASK, meas_read), (39 - 13));
60 
61 	fine = div64_s64(fine * NSEC_PER_SEC, idtfc3->tdc_apll_freq * 62LL);
62 	coarse = div64_s64(coarse * NSEC_PER_SEC, idtfc3->time_ref_freq);
63 
64 	return coarse + fine;
65 }
66 
67 static s64 tdc_offset2phase(struct idtfc3 *idtfc3, s64 offset_ns)
68 {
69 	if (offset_ns > idtfc3->ns_per_sync / 2)
70 		offset_ns -= idtfc3->ns_per_sync;
71 
72 	return offset_ns * idtfc3->tdc_offset_sign;
73 }
74 
75 static int idtfc3_set_lpf_mode(struct idtfc3 *idtfc3, u8 mode)
76 {
77 	int err;
78 
79 	if (mode >= LPF_INVALID)
80 		return -EINVAL;
81 
82 	if (idtfc3->lpf_mode == mode)
83 		return 0;
84 
85 	err = regmap_bulk_write(idtfc3->regmap, LPF_MODE_CNFG, &mode, sizeof(mode));
86 	if (err)
87 		return err;
88 
89 	idtfc3->lpf_mode = mode;
90 
91 	return 0;
92 }
93 
94 static int idtfc3_enable_lpf(struct idtfc3 *idtfc3, bool enable)
95 {
96 	u8 val;
97 	int err;
98 
99 	err = regmap_bulk_read(idtfc3->regmap, LPF_CTRL, &val, sizeof(val));
100 	if (err)
101 		return err;
102 
103 	if (enable == true)
104 		val |= LPF_EN;
105 	else
106 		val &= ~LPF_EN;
107 
108 	return regmap_bulk_write(idtfc3->regmap, LPF_CTRL, &val, sizeof(val));
109 }
110 
111 static int idtfc3_get_time_ref_freq(struct idtfc3 *idtfc3)
112 {
113 	int err;
114 	u8 buf[4];
115 	u8 time_ref_div;
116 	u8 time_clk_div;
117 
118 	err = regmap_bulk_read(idtfc3->regmap, TIME_CLOCK_MEAS_DIV_CNFG, buf, sizeof(buf));
119 	if (err)
120 		return err;
121 	time_ref_div = FIELD_GET(TIME_REF_DIV_MASK, get_unaligned_le32(buf)) + 1;
122 
123 	err = regmap_bulk_read(idtfc3->regmap, TIME_CLOCK_COUNT, buf, 1);
124 	if (err)
125 		return err;
126 	time_clk_div = (buf[0] & TIME_CLOCK_COUNT_MASK) + 1;
127 	idtfc3->time_ref_freq = idtfc3->hw_param.time_clk_freq *
128 				time_clk_div / time_ref_div;
129 
130 	return 0;
131 }
132 
133 static int idtfc3_get_tdc_offset_sign(struct idtfc3 *idtfc3)
134 {
135 	int err;
136 	u8 buf[4];
137 	u32 val;
138 	u8 sig1, sig2;
139 
140 	err = regmap_bulk_read(idtfc3->regmap, TIME_CLOCK_TDC_FANOUT_CNFG, buf, sizeof(buf));
141 	if (err)
142 		return err;
143 
144 	val = get_unaligned_le32(buf);
145 	if ((val & TIME_SYNC_TO_TDC_EN) != TIME_SYNC_TO_TDC_EN) {
146 		dev_err(idtfc3->dev, "TIME_SYNC_TO_TDC_EN is off !!!");
147 		return -EINVAL;
148 	}
149 
150 	sig1 = FIELD_GET(SIG1_MUX_SEL_MASK, val);
151 	sig2 = FIELD_GET(SIG2_MUX_SEL_MASK, val);
152 
153 	if ((sig1 == sig2) || ((sig1 != TIME_SYNC) && (sig2 != TIME_SYNC))) {
154 		dev_err(idtfc3->dev, "Invalid tdc_mux_sel sig1=%d sig2=%d", sig1, sig2);
155 		return -EINVAL;
156 	} else if (sig1 == TIME_SYNC) {
157 		idtfc3->tdc_offset_sign = 1;
158 	} else if (sig2 == TIME_SYNC) {
159 		idtfc3->tdc_offset_sign = -1;
160 	}
161 
162 	return 0;
163 }
164 
165 static int idtfc3_lpf_bw(struct idtfc3 *idtfc3, u8 shift, u8 mult)
166 {
167 	u8 val = FIELD_PREP(LPF_BW_SHIFT, shift) | FIELD_PREP(LPF_BW_MULT, mult);
168 
169 	return regmap_bulk_write(idtfc3->regmap, LPF_BW_CNFG, &val, sizeof(val));
170 }
171 
172 static int idtfc3_enable_tdc(struct idtfc3 *idtfc3, bool enable, u8 meas_mode)
173 {
174 	int err;
175 	u8 val = 0;
176 
177 	/* Disable TDC first */
178 	err = regmap_bulk_write(idtfc3->regmap, TIME_CLOCK_MEAS_CTRL, &val, sizeof(val));
179 	if (err)
180 		return err;
181 
182 	if (enable == false)
183 		return idtfc3_lpf_bw(idtfc3, LPF_BW_SHIFT_DEFAULT, LPF_BW_MULT_DEFAULT);
184 
185 	if (meas_mode >= MEAS_MODE_INVALID)
186 		return -EINVAL;
187 
188 	/* Change TDC meas mode */
189 	err = regmap_bulk_write(idtfc3->regmap, TIME_CLOCK_MEAS_CNFG,
190 				&meas_mode, sizeof(meas_mode));
191 	if (err)
192 		return err;
193 
194 	/* Enable TDC */
195 	val = TDC_MEAS_EN;
196 	if (meas_mode == CONTINUOUS)
197 		val |= TDC_MEAS_START;
198 	err = regmap_bulk_write(idtfc3->regmap, TIME_CLOCK_MEAS_CTRL, &val, sizeof(val));
199 	if (err)
200 		return err;
201 
202 	return idtfc3_lpf_bw(idtfc3, LPF_BW_SHIFT_1PPS, LPF_BW_MULT_DEFAULT);
203 }
204 
205 static bool get_tdc_meas(struct idtfc3 *idtfc3, s64 *offset_ns)
206 {
207 	bool valid = false;
208 	u8 buf[9];
209 	u8 val;
210 	int err;
211 
212 	while (true) {
213 		err = regmap_bulk_read(idtfc3->regmap, TDC_FIFO_STS,
214 				       &val, sizeof(val));
215 		if (err)
216 			return false;
217 
218 		if (val & FIFO_EMPTY)
219 			break;
220 
221 		err = regmap_bulk_read(idtfc3->regmap, TDC_FIFO_READ_REQ,
222 				       &buf, sizeof(buf));
223 		if (err)
224 			return false;
225 
226 		valid = true;
227 	}
228 
229 	if (valid)
230 		*offset_ns = tdc_meas2offset(idtfc3, get_unaligned_le64(&buf[1]));
231 
232 	return valid;
233 }
234 
235 static int check_tdc_fifo_overrun(struct idtfc3 *idtfc3)
236 {
237 	u8 val;
238 	int err;
239 
240 	/* Check if FIFO is overrun */
241 	err = regmap_bulk_read(idtfc3->regmap, TDC_FIFO_STS, &val, sizeof(val));
242 	if (err)
243 		return err;
244 
245 	if (!(val & FIFO_FULL))
246 		return 0;
247 
248 	dev_warn(idtfc3->dev, "TDC FIFO overrun !!!");
249 
250 	err = idtfc3_enable_tdc(idtfc3, true, CONTINUOUS);
251 	if (err)
252 		return err;
253 
254 	return 0;
255 }
256 
257 static int get_tdc_meas_continuous(struct idtfc3 *idtfc3)
258 {
259 	int err;
260 	s64 offset_ns;
261 	struct ptp_clock_event event;
262 
263 	err = check_tdc_fifo_overrun(idtfc3);
264 	if (err)
265 		return err;
266 
267 	if (get_tdc_meas(idtfc3, &offset_ns) && offset_ns >= 0) {
268 		event.index = 0;
269 		event.offset = tdc_offset2phase(idtfc3, offset_ns);
270 		event.type = PTP_CLOCK_EXTOFF;
271 		ptp_clock_event(idtfc3->ptp_clock, &event);
272 	}
273 
274 	return 0;
275 }
276 
277 static int idtfc3_read_subcounter(struct idtfc3 *idtfc3)
278 {
279 	u8 buf[5] = {0};
280 	int err;
281 
282 	err = regmap_bulk_read(idtfc3->regmap, TOD_COUNTER_READ_REQ,
283 			       &buf, sizeof(buf));
284 	if (err)
285 		return err;
286 
287 	/* sync_counter_value is [31:82] and sub_sync_counter_value is [0:30] */
288 	return get_unaligned_le32(&buf[1]) & SUB_SYNC_COUNTER_MASK;
289 }
290 
291 static int idtfc3_tod_update_is_done(struct idtfc3 *idtfc3)
292 {
293 	int err;
294 	u8 req;
295 
296 	err = read_poll_timeout_atomic(regmap_bulk_read, err, !req, USEC_PER_MSEC,
297 				       idtfc3->tc_write_timeout, true, idtfc3->regmap,
298 				       TOD_SYNC_LOAD_REQ_CTRL, &req, 1);
299 	if (err)
300 		dev_err(idtfc3->dev, "TOD counter write timeout !!!");
301 
302 	return err;
303 }
304 
305 static int idtfc3_write_subcounter(struct idtfc3 *idtfc3, u32 counter)
306 {
307 	u8 buf[18] = {0};
308 	int err;
309 
310 	/* sync_counter_value is [31:82] and sub_sync_counter_value is [0:30] */
311 	put_unaligned_le32(counter & SUB_SYNC_COUNTER_MASK, &buf[0]);
312 
313 	buf[16] = SUB_SYNC_LOAD_ENABLE | SYNC_LOAD_ENABLE;
314 	buf[17] = SYNC_LOAD_REQ;
315 
316 	err = regmap_bulk_write(idtfc3->regmap, TOD_SYNC_LOAD_VAL_CTRL,
317 				&buf, sizeof(buf));
318 	if (err)
319 		return err;
320 
321 	return idtfc3_tod_update_is_done(idtfc3);
322 }
323 
324 static int idtfc3_timecounter_update(struct idtfc3 *idtfc3, u32 counter, s64 ns)
325 {
326 	int err;
327 
328 	err = idtfc3_write_subcounter(idtfc3, counter);
329 	if (err)
330 		return err;
331 
332 	/* Update time counter */
333 	idtfc3->ns = ns;
334 	idtfc3->last_counter = counter;
335 
336 	return 0;
337 }
338 
339 static int idtfc3_timecounter_read(struct idtfc3 *idtfc3)
340 {
341 	int now, delta;
342 
343 	now = idtfc3_read_subcounter(idtfc3);
344 	if (now < 0)
345 		return now;
346 
347 	/* calculate the delta since the last idtfc3_timecounter_read(): */
348 	if (now >= idtfc3->last_counter)
349 		delta = now - idtfc3->last_counter;
350 	else
351 		delta = idtfc3->sub_sync_count - idtfc3->last_counter + now;
352 
353 	/* Update time counter */
354 	idtfc3->ns += delta * idtfc3->ns_per_counter;
355 	idtfc3->last_counter = now;
356 
357 	return 0;
358 }
359 
360 static int _idtfc3_gettime(struct idtfc3 *idtfc3, struct timespec64 *ts)
361 {
362 	int err;
363 
364 	err = idtfc3_timecounter_read(idtfc3);
365 	if (err)
366 		return err;
367 
368 	*ts = ns_to_timespec64(idtfc3->ns);
369 
370 	return 0;
371 }
372 
373 static int idtfc3_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
374 {
375 	struct idtfc3 *idtfc3 = container_of(ptp, struct idtfc3, caps);
376 	int err;
377 
378 	mutex_lock(idtfc3->lock);
379 	err = _idtfc3_gettime(idtfc3, ts);
380 	mutex_unlock(idtfc3->lock);
381 
382 	return err;
383 }
384 
385 static int _idtfc3_settime(struct idtfc3 *idtfc3, const struct timespec64 *ts)
386 {
387 	s64 offset_ns, now_ns;
388 	u32 counter, sub_ns;
389 	int now;
390 
391 	if (timespec64_valid(ts) == false) {
392 		dev_err(idtfc3->dev, "%s: invalid timespec", __func__);
393 		return -EINVAL;
394 	}
395 
396 	now = idtfc3_read_subcounter(idtfc3);
397 	if (now < 0)
398 		return now;
399 
400 	offset_ns = (idtfc3->sub_sync_count - now) * idtfc3->ns_per_counter;
401 	now_ns = timespec64_to_ns(ts);
402 	(void)ns2counters(idtfc3, offset_ns + now_ns, &sub_ns);
403 
404 	counter = sub_ns / idtfc3->ns_per_counter;
405 	return idtfc3_timecounter_update(idtfc3, counter, now_ns);
406 }
407 
408 static int idtfc3_settime(struct ptp_clock_info *ptp, const struct timespec64 *ts)
409 {
410 	struct idtfc3 *idtfc3 = container_of(ptp, struct idtfc3, caps);
411 	int err;
412 
413 	mutex_lock(idtfc3->lock);
414 	err = _idtfc3_settime(idtfc3, ts);
415 	mutex_unlock(idtfc3->lock);
416 
417 	return err;
418 }
419 
420 static int _idtfc3_adjtime(struct idtfc3 *idtfc3, s64 delta)
421 {
422 	/*
423 	 * The TOD counter can be synchronously loaded with any value,
424 	 * to be loaded on the next Time Sync pulse
425 	 */
426 	s64 sync_ns;
427 	u32 sub_ns;
428 	u32 counter;
429 
430 	if (idtfc3->ns + delta < 0) {
431 		dev_err(idtfc3->dev, "%lld ns adj is too large", delta);
432 		return -EINVAL;
433 	}
434 
435 	sync_ns = ns2counters(idtfc3, delta + idtfc3->ns_per_sync, &sub_ns);
436 
437 	counter = sub_ns / idtfc3->ns_per_counter;
438 	return idtfc3_timecounter_update(idtfc3, counter, idtfc3->ns + sync_ns +
439 									counter * idtfc3->ns_per_counter);
440 }
441 
442 static int idtfc3_adjtime(struct ptp_clock_info *ptp, s64 delta)
443 {
444 	struct idtfc3 *idtfc3 = container_of(ptp, struct idtfc3, caps);
445 	int err;
446 
447 	mutex_lock(idtfc3->lock);
448 	err = _idtfc3_adjtime(idtfc3, delta);
449 	mutex_unlock(idtfc3->lock);
450 
451 	return err;
452 }
453 
454 static int _idtfc3_adjphase(struct idtfc3 *idtfc3, s32 delta)
455 {
456 	u8 buf[8] = {0};
457 	int err;
458 	s64 pcw;
459 
460 	err = idtfc3_set_lpf_mode(idtfc3, LPF_WP);
461 	if (err)
462 		return err;
463 
464 	/*
465 	 * Phase Control Word unit is: 10^9 / (TDC_APLL_FREQ * 124)
466 	 *
467 	 *       delta * TDC_APLL_FREQ * 124
468 	 * PCW = ---------------------------
469 	 *                  10^9
470 	 *
471 	 */
472 	pcw = div_s64((s64)delta * idtfc3->tdc_apll_freq * 124, NSEC_PER_SEC);
473 
474 	put_unaligned_le64(pcw, buf);
475 
476 	return regmap_bulk_write(idtfc3->regmap, LPF_WR_PHASE_CTRL, buf, sizeof(buf));
477 }
478 
479 static int idtfc3_adjphase(struct ptp_clock_info *ptp, s32 delta)
480 {
481 	struct idtfc3 *idtfc3 = container_of(ptp, struct idtfc3, caps);
482 	int err;
483 
484 	mutex_lock(idtfc3->lock);
485 	err = _idtfc3_adjphase(idtfc3, delta);
486 	mutex_unlock(idtfc3->lock);
487 
488 	return err;
489 }
490 
491 static int _idtfc3_adjfine(struct idtfc3 *idtfc3, long scaled_ppm)
492 {
493 	u8 buf[8] = {0};
494 	int err;
495 	s64 fcw;
496 
497 	err = idtfc3_set_lpf_mode(idtfc3, LPF_WF);
498 	if (err)
499 		return err;
500 
501 	/*
502 	 * Frequency Control Word unit is: 2^-44 * 10^6 ppm
503 	 *
504 	 * adjfreq:
505 	 *       ppb * 2^44
506 	 * FCW = ----------
507 	 *          10^9
508 	 *
509 	 * adjfine:
510 	 *       ppm_16 * 2^28
511 	 * FCW = -------------
512 	 *           10^6
513 	 */
514 	fcw = scaled_ppm * BIT(28);
515 	fcw = div_s64(fcw, 1000000);
516 
517 	put_unaligned_le64(fcw, buf);
518 
519 	return regmap_bulk_write(idtfc3->regmap, LPF_WR_FREQ_CTRL, buf, sizeof(buf));
520 }
521 
522 static int idtfc3_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
523 {
524 	struct idtfc3 *idtfc3 = container_of(ptp, struct idtfc3, caps);
525 	int err;
526 
527 	mutex_lock(idtfc3->lock);
528 	err = _idtfc3_adjfine(idtfc3, scaled_ppm);
529 	mutex_unlock(idtfc3->lock);
530 
531 	return err;
532 }
533 
534 static int idtfc3_enable(struct ptp_clock_info *ptp,
535 			 struct ptp_clock_request *rq, int on)
536 {
537 	struct idtfc3 *idtfc3 = container_of(ptp, struct idtfc3, caps);
538 	int err = -EOPNOTSUPP;
539 
540 	mutex_lock(idtfc3->lock);
541 	switch (rq->type) {
542 	case PTP_CLK_REQ_PEROUT:
543 		if (!on)
544 			err = 0;
545 		/* Only accept a 1-PPS aligned to the second. */
546 		else if (rq->perout.start.nsec || rq->perout.period.sec != 1 ||
547 			 rq->perout.period.nsec)
548 			err = -ERANGE;
549 		else
550 			err = 0;
551 		break;
552 	case PTP_CLK_REQ_EXTTS:
553 		if (on) {
554 			/* Only accept requests for external phase offset */
555 			if ((rq->extts.flags & PTP_EXT_OFFSET) != (PTP_EXT_OFFSET))
556 				err = -EOPNOTSUPP;
557 			else
558 				err = idtfc3_enable_tdc(idtfc3, true, CONTINUOUS);
559 		} else {
560 			err = idtfc3_enable_tdc(idtfc3, false, MEAS_MODE_INVALID);
561 		}
562 		break;
563 	default:
564 		break;
565 	}
566 	mutex_unlock(idtfc3->lock);
567 
568 	if (err)
569 		dev_err(idtfc3->dev, "Failed in %s with err %d!", __func__, err);
570 
571 	return err;
572 }
573 
574 static long idtfc3_aux_work(struct ptp_clock_info *ptp)
575 {
576 	struct idtfc3 *idtfc3 = container_of(ptp, struct idtfc3, caps);
577 	static int tdc_get;
578 
579 	mutex_lock(idtfc3->lock);
580 	tdc_get %= TDC_GET_PERIOD;
581 	if ((tdc_get == 0) || (tdc_get == TDC_GET_PERIOD / 2))
582 		idtfc3_timecounter_read(idtfc3);
583 	get_tdc_meas_continuous(idtfc3);
584 	tdc_get++;
585 	mutex_unlock(idtfc3->lock);
586 
587 	return idtfc3->tc_update_period;
588 }
589 
590 static const struct ptp_clock_info idtfc3_caps = {
591 	.owner		= THIS_MODULE,
592 	.max_adj	= MAX_FFO_PPB,
593 	.n_per_out	= 1,
594 	.n_ext_ts	= 1,
595 	.adjphase	= &idtfc3_adjphase,
596 	.adjfine	= &idtfc3_adjfine,
597 	.adjtime	= &idtfc3_adjtime,
598 	.gettime64	= &idtfc3_gettime,
599 	.settime64	= &idtfc3_settime,
600 	.enable		= &idtfc3_enable,
601 	.do_aux_work	= &idtfc3_aux_work,
602 };
603 
604 static int idtfc3_hw_calibrate(struct idtfc3 *idtfc3)
605 {
606 	int err = 0;
607 	u8 val;
608 
609 	mdelay(10);
610 	/*
611 	 * Toggle TDC_DAC_RECAL_REQ:
612 	 * (1) set tdc_en to 1
613 	 * (2) set tdc_dac_recal_req to 0
614 	 * (3) set tdc_dac_recal_req to 1
615 	 */
616 	val = TDC_EN;
617 	err = regmap_bulk_write(idtfc3->regmap, TDC_CTRL,
618 				&val, sizeof(val));
619 	if (err)
620 		return err;
621 	val = TDC_EN | TDC_DAC_RECAL_REQ;
622 	err = regmap_bulk_write(idtfc3->regmap, TDC_CTRL,
623 				&val, sizeof(val));
624 	if (err)
625 		return err;
626 	mdelay(10);
627 
628 	/*
629 	 * Toggle APLL_REINIT:
630 	 * (1) set apll_reinit to 0
631 	 * (2) set apll_reinit to 1
632 	 */
633 	val = 0;
634 	err = regmap_bulk_write(idtfc3->regmap, SOFT_RESET_CTRL,
635 				&val, sizeof(val));
636 	if (err)
637 		return err;
638 	val = APLL_REINIT;
639 	err = regmap_bulk_write(idtfc3->regmap, SOFT_RESET_CTRL,
640 				&val, sizeof(val));
641 	if (err)
642 		return err;
643 	mdelay(10);
644 
645 	return err;
646 }
647 
648 static int idtfc3_init_timecounter(struct idtfc3 *idtfc3)
649 {
650 	int err;
651 	u32 period_ms;
652 
653 	period_ms = idtfc3->sub_sync_count * MSEC_PER_SEC /
654 			idtfc3->hw_param.time_clk_freq;
655 
656 	idtfc3->tc_update_period = msecs_to_jiffies(period_ms / TDC_GET_PERIOD);
657 	idtfc3->tc_write_timeout = period_ms * USEC_PER_MSEC;
658 
659 	err = idtfc3_timecounter_update(idtfc3, 0, 0);
660 	if (err)
661 		return err;
662 
663 	err = idtfc3_timecounter_read(idtfc3);
664 	if (err)
665 		return err;
666 
667 	ptp_schedule_worker(idtfc3->ptp_clock, idtfc3->tc_update_period);
668 
669 	return 0;
670 }
671 
672 static int idtfc3_get_tdc_apll_freq(struct idtfc3 *idtfc3)
673 {
674 	int err;
675 	u8 tdc_fb_div_int;
676 	u8 tdc_ref_div;
677 	struct idtfc3_hw_param *param = &idtfc3->hw_param;
678 
679 	err = regmap_bulk_read(idtfc3->regmap, TDC_REF_DIV_CNFG,
680 				&tdc_ref_div, sizeof(tdc_ref_div));
681 	if (err)
682 		return err;
683 
684 	err = regmap_bulk_read(idtfc3->regmap, TDC_FB_DIV_INT_CNFG,
685 				&tdc_fb_div_int, sizeof(tdc_fb_div_int));
686 	if (err)
687 		return err;
688 
689 	tdc_fb_div_int &= TDC_FB_DIV_INT_MASK;
690 	tdc_ref_div &= TDC_REF_DIV_CONFIG_MASK;
691 
692 	idtfc3->tdc_apll_freq = div_u64(param->xtal_freq * (u64)tdc_fb_div_int,
693 					1 << tdc_ref_div);
694 
695 	return 0;
696 }
697 
698 static int idtfc3_get_fod(struct idtfc3 *idtfc3)
699 {
700 	int err;
701 	u8 fod;
702 
703 	err = regmap_bulk_read(idtfc3->regmap, TIME_CLOCK_SRC, &fod, sizeof(fod));
704 	if (err)
705 		return err;
706 
707 	switch (fod) {
708 	case 0:
709 		idtfc3->fod_n = FOD_0;
710 		break;
711 	case 1:
712 		idtfc3->fod_n = FOD_1;
713 		break;
714 	case 2:
715 		idtfc3->fod_n = FOD_2;
716 		break;
717 	default:
718 		return -EINVAL;
719 	}
720 
721 	return 0;
722 }
723 
724 static int idtfc3_get_sync_count(struct idtfc3 *idtfc3)
725 {
726 	int err;
727 	u8 buf[4];
728 
729 	err = regmap_bulk_read(idtfc3->regmap, SUB_SYNC_GEN_CNFG, buf, sizeof(buf));
730 	if (err)
731 		return err;
732 
733 	idtfc3->sub_sync_count = (get_unaligned_le32(buf) & SUB_SYNC_COUNTER_MASK) + 1;
734 	idtfc3->ns_per_counter = NSEC_PER_SEC / idtfc3->hw_param.time_clk_freq;
735 	idtfc3->ns_per_sync = idtfc3->sub_sync_count * idtfc3->ns_per_counter;
736 
737 	return 0;
738 }
739 
740 static int idtfc3_setup_hw_param(struct idtfc3 *idtfc3)
741 {
742 	int err;
743 
744 	err = idtfc3_get_fod(idtfc3);
745 	if (err)
746 		return err;
747 
748 	err = idtfc3_get_sync_count(idtfc3);
749 	if (err)
750 		return err;
751 
752 	err = idtfc3_get_time_ref_freq(idtfc3);
753 	if (err)
754 		return err;
755 
756 	return idtfc3_get_tdc_apll_freq(idtfc3);
757 }
758 
759 static int idtfc3_configure_hw(struct idtfc3 *idtfc3)
760 {
761 	int err = 0;
762 
763 	err = idtfc3_hw_calibrate(idtfc3);
764 	if (err)
765 		return err;
766 
767 	err = idtfc3_enable_lpf(idtfc3, true);
768 	if (err)
769 		return err;
770 
771 	err = idtfc3_enable_tdc(idtfc3, false, MEAS_MODE_INVALID);
772 	if (err)
773 		return err;
774 
775 	err = idtfc3_get_tdc_offset_sign(idtfc3);
776 	if (err)
777 		return err;
778 
779 	return idtfc3_setup_hw_param(idtfc3);
780 }
781 
782 static int idtfc3_set_overhead(struct idtfc3 *idtfc3)
783 {
784 	s64 current_ns = 0;
785 	s64 lowest_ns = 0;
786 	int err;
787 	u8 i;
788 	ktime_t start;
789 	ktime_t stop;
790 	ktime_t diff;
791 
792 	char buf[18] = {0};
793 
794 	for (i = 0; i < 5; i++) {
795 		start = ktime_get_raw();
796 
797 		err = regmap_bulk_write(idtfc3->regmap, TOD_SYNC_LOAD_VAL_CTRL,
798 					&buf, sizeof(buf));
799 		if (err)
800 			return err;
801 
802 		stop = ktime_get_raw();
803 
804 		diff = ktime_sub(stop, start);
805 
806 		current_ns = ktime_to_ns(diff);
807 
808 		if (i == 0) {
809 			lowest_ns = current_ns;
810 		} else {
811 			if (current_ns < lowest_ns)
812 				lowest_ns = current_ns;
813 		}
814 	}
815 
816 	idtfc3->tod_write_overhead = lowest_ns;
817 
818 	return err;
819 }
820 
821 static int idtfc3_enable_ptp(struct idtfc3 *idtfc3)
822 {
823 	int err;
824 
825 	idtfc3->caps = idtfc3_caps;
826 	snprintf(idtfc3->caps.name, sizeof(idtfc3->caps.name), "IDT FC3W");
827 	idtfc3->ptp_clock = ptp_clock_register(&idtfc3->caps, NULL);
828 
829 	if (IS_ERR(idtfc3->ptp_clock)) {
830 		err = PTR_ERR(idtfc3->ptp_clock);
831 		idtfc3->ptp_clock = NULL;
832 		return err;
833 	}
834 
835 	err = idtfc3_set_overhead(idtfc3);
836 	if (err)
837 		return err;
838 
839 	err = idtfc3_init_timecounter(idtfc3);
840 	if (err)
841 		return err;
842 
843 	dev_info(idtfc3->dev, "TIME_SYNC_CHANNEL registered as ptp%d",
844 		 idtfc3->ptp_clock->index);
845 
846 	return 0;
847 }
848 
849 static int idtfc3_load_firmware(struct idtfc3 *idtfc3)
850 {
851 	char fname[128] = FW_FILENAME;
852 	const struct firmware *fw;
853 	struct idtfc3_fwrc *rec;
854 	u16 addr;
855 	u8 val;
856 	int err;
857 	s32 len;
858 
859 	idtfc3_default_hw_param(&idtfc3->hw_param);
860 
861 	if (firmware) /* module parameter */
862 		snprintf(fname, sizeof(fname), "%s", firmware);
863 
864 	dev_info(idtfc3->dev, "requesting firmware '%s'\n", fname);
865 
866 	err = request_firmware(&fw, fname, idtfc3->dev);
867 
868 	if (err) {
869 		dev_err(idtfc3->dev,
870 			"requesting firmware failed with err %d!\n", err);
871 		return err;
872 	}
873 
874 	dev_dbg(idtfc3->dev, "firmware size %zu bytes\n", fw->size);
875 
876 	rec = (struct idtfc3_fwrc *)fw->data;
877 
878 	for (len = fw->size; len > 0; len -= sizeof(*rec)) {
879 		if (rec->reserved) {
880 			dev_err(idtfc3->dev,
881 				"bad firmware, reserved field non-zero\n");
882 			err = -EINVAL;
883 		} else {
884 			val = rec->value;
885 			addr = rec->hiaddr << 8 | rec->loaddr;
886 
887 			rec++;
888 
889 			err = idtfc3_set_hw_param(&idtfc3->hw_param, addr, val);
890 		}
891 
892 		if (err != -EINVAL) {
893 			err = 0;
894 
895 			/* Max register */
896 			if (addr >= 0xE88)
897 				continue;
898 
899 			err = regmap_bulk_write(idtfc3->regmap, addr,
900 						&val, sizeof(val));
901 		}
902 
903 		if (err)
904 			goto out;
905 	}
906 
907 	err = idtfc3_configure_hw(idtfc3);
908 out:
909 	release_firmware(fw);
910 	return err;
911 }
912 
913 static int idtfc3_read_device_id(struct idtfc3 *idtfc3, u16 *device_id)
914 {
915 	int err;
916 	u8 buf[2] = {0};
917 
918 	err = regmap_bulk_read(idtfc3->regmap, DEVICE_ID,
919 			       &buf, sizeof(buf));
920 	if (err) {
921 		dev_err(idtfc3->dev, "%s failed with %d", __func__, err);
922 		return err;
923 	}
924 
925 	*device_id = get_unaligned_le16(buf);
926 
927 	return 0;
928 }
929 
930 static int idtfc3_check_device_compatibility(struct idtfc3 *idtfc3)
931 {
932 	int err;
933 	u16 device_id;
934 
935 	err = idtfc3_read_device_id(idtfc3, &device_id);
936 	if (err)
937 		return err;
938 
939 	if ((device_id & DEVICE_ID_MASK) == 0) {
940 		dev_err(idtfc3->dev, "invalid device");
941 		return -EINVAL;
942 	}
943 
944 	return 0;
945 }
946 
947 static int idtfc3_probe(struct platform_device *pdev)
948 {
949 	struct rsmu_ddata *ddata = dev_get_drvdata(pdev->dev.parent);
950 	struct idtfc3 *idtfc3;
951 	int err;
952 
953 	idtfc3 = devm_kzalloc(&pdev->dev, sizeof(struct idtfc3), GFP_KERNEL);
954 
955 	if (!idtfc3)
956 		return -ENOMEM;
957 
958 	idtfc3->dev = &pdev->dev;
959 	idtfc3->mfd = pdev->dev.parent;
960 	idtfc3->lock = &ddata->lock;
961 	idtfc3->regmap = ddata->regmap;
962 
963 	mutex_lock(idtfc3->lock);
964 
965 	err = idtfc3_check_device_compatibility(idtfc3);
966 	if (err) {
967 		mutex_unlock(idtfc3->lock);
968 		return err;
969 	}
970 
971 	err = idtfc3_load_firmware(idtfc3);
972 	if (err) {
973 		if (err == -ENOENT) {
974 			mutex_unlock(idtfc3->lock);
975 			return -EPROBE_DEFER;
976 		}
977 		dev_warn(idtfc3->dev, "loading firmware failed with %d", err);
978 	}
979 
980 	err = idtfc3_enable_ptp(idtfc3);
981 	if (err) {
982 		dev_err(idtfc3->dev, "idtfc3_enable_ptp failed with %d", err);
983 		mutex_unlock(idtfc3->lock);
984 		return err;
985 	}
986 
987 	mutex_unlock(idtfc3->lock);
988 
989 	if (err) {
990 		ptp_clock_unregister(idtfc3->ptp_clock);
991 		return err;
992 	}
993 
994 	platform_set_drvdata(pdev, idtfc3);
995 
996 	return 0;
997 }
998 
999 static int idtfc3_remove(struct platform_device *pdev)
1000 {
1001 	struct idtfc3 *idtfc3 = platform_get_drvdata(pdev);
1002 
1003 	ptp_clock_unregister(idtfc3->ptp_clock);
1004 
1005 	return 0;
1006 }
1007 
1008 static struct platform_driver idtfc3_driver = {
1009 	.driver = {
1010 		.name = "rc38xxx-phc",
1011 	},
1012 	.probe = idtfc3_probe,
1013 	.remove	= idtfc3_remove,
1014 };
1015 
1016 module_platform_driver(idtfc3_driver);
1017