xref: /openbmc/linux/drivers/net/dsa/mv88e6xxx/ptp.c (revision e15a5365)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Marvell 88E6xxx Switch PTP support
4  *
5  * Copyright (c) 2008 Marvell Semiconductor
6  *
7  * Copyright (c) 2017 National Instruments
8  *      Erik Hons <erik.hons@ni.com>
9  *      Brandon Streiff <brandon.streiff@ni.com>
10  *      Dane Wagner <dane.wagner@ni.com>
11  */
12 
13 #include "chip.h"
14 #include "global2.h"
15 #include "hwtstamp.h"
16 #include "ptp.h"
17 
18 #define MV88E6XXX_MAX_ADJ_PPB	1000000
19 
20 /* Family MV88E6250:
21  * Raw timestamps are in units of 10-ns clock periods.
22  *
23  * clkadj = scaled_ppm * 10*2^28 / (10^6 * 2^16)
24  * simplifies to
25  * clkadj = scaled_ppm * 2^7 / 5^5
26  */
27 #define MV88E6250_CC_SHIFT	28
28 #define MV88E6250_CC_MULT	(10 << MV88E6250_CC_SHIFT)
29 #define MV88E6250_CC_MULT_NUM	(1 << 7)
30 #define MV88E6250_CC_MULT_DEM	3125ULL
31 
32 /* Other families:
33  * Raw timestamps are in units of 8-ns clock periods.
34  *
35  * clkadj = scaled_ppm * 8*2^28 / (10^6 * 2^16)
36  * simplifies to
37  * clkadj = scaled_ppm * 2^9 / 5^6
38  */
39 #define MV88E6XXX_CC_SHIFT	28
40 #define MV88E6XXX_CC_MULT	(8 << MV88E6XXX_CC_SHIFT)
41 #define MV88E6XXX_CC_MULT_NUM	(1 << 9)
42 #define MV88E6XXX_CC_MULT_DEM	15625ULL
43 
44 #define TAI_EVENT_WORK_INTERVAL msecs_to_jiffies(100)
45 
46 #define cc_to_chip(cc) container_of(cc, struct mv88e6xxx_chip, tstamp_cc)
47 #define dw_overflow_to_chip(dw) container_of(dw, struct mv88e6xxx_chip, \
48 					     overflow_work)
49 #define dw_tai_event_to_chip(dw) container_of(dw, struct mv88e6xxx_chip, \
50 					      tai_event_work)
51 
52 static int mv88e6xxx_tai_read(struct mv88e6xxx_chip *chip, int addr,
53 			      u16 *data, int len)
54 {
55 	if (!chip->info->ops->avb_ops->tai_read)
56 		return -EOPNOTSUPP;
57 
58 	return chip->info->ops->avb_ops->tai_read(chip, addr, data, len);
59 }
60 
61 static int mv88e6xxx_tai_write(struct mv88e6xxx_chip *chip, int addr, u16 data)
62 {
63 	if (!chip->info->ops->avb_ops->tai_write)
64 		return -EOPNOTSUPP;
65 
66 	return chip->info->ops->avb_ops->tai_write(chip, addr, data);
67 }
68 
69 /* TODO: places where this are called should be using pinctrl */
70 static int mv88e6352_set_gpio_func(struct mv88e6xxx_chip *chip, int pin,
71 				   int func, int input)
72 {
73 	int err;
74 
75 	if (!chip->info->ops->gpio_ops)
76 		return -EOPNOTSUPP;
77 
78 	err = chip->info->ops->gpio_ops->set_dir(chip, pin, input);
79 	if (err)
80 		return err;
81 
82 	return chip->info->ops->gpio_ops->set_pctl(chip, pin, func);
83 }
84 
85 static u64 mv88e6352_ptp_clock_read(const struct cyclecounter *cc)
86 {
87 	struct mv88e6xxx_chip *chip = cc_to_chip(cc);
88 	u16 phc_time[2];
89 	int err;
90 
91 	err = mv88e6xxx_tai_read(chip, MV88E6XXX_TAI_TIME_LO, phc_time,
92 				 ARRAY_SIZE(phc_time));
93 	if (err)
94 		return 0;
95 	else
96 		return ((u32)phc_time[1] << 16) | phc_time[0];
97 }
98 
99 static u64 mv88e6165_ptp_clock_read(const struct cyclecounter *cc)
100 {
101 	struct mv88e6xxx_chip *chip = cc_to_chip(cc);
102 	u16 phc_time[2];
103 	int err;
104 
105 	err = mv88e6xxx_tai_read(chip, MV88E6XXX_PTP_GC_TIME_LO, phc_time,
106 				 ARRAY_SIZE(phc_time));
107 	if (err)
108 		return 0;
109 	else
110 		return ((u32)phc_time[1] << 16) | phc_time[0];
111 }
112 
113 /* mv88e6352_config_eventcap - configure TAI event capture
114  * @event: PTP_CLOCK_PPS (internal) or PTP_CLOCK_EXTTS (external)
115  * @rising: zero for falling-edge trigger, else rising-edge trigger
116  *
117  * This will also reset the capture sequence counter.
118  */
119 static int mv88e6352_config_eventcap(struct mv88e6xxx_chip *chip, int event,
120 				     int rising)
121 {
122 	u16 global_config;
123 	u16 cap_config;
124 	int err;
125 
126 	chip->evcap_config = MV88E6XXX_TAI_CFG_CAP_OVERWRITE |
127 			     MV88E6XXX_TAI_CFG_CAP_CTR_START;
128 	if (!rising)
129 		chip->evcap_config |= MV88E6XXX_TAI_CFG_EVREQ_FALLING;
130 
131 	global_config = (chip->evcap_config | chip->trig_config);
132 	err = mv88e6xxx_tai_write(chip, MV88E6XXX_TAI_CFG, global_config);
133 	if (err)
134 		return err;
135 
136 	if (event == PTP_CLOCK_PPS) {
137 		cap_config = MV88E6XXX_TAI_EVENT_STATUS_CAP_TRIG;
138 	} else if (event == PTP_CLOCK_EXTTS) {
139 		/* if STATUS_CAP_TRIG is unset we capture PTP_EVREQ events */
140 		cap_config = 0;
141 	} else {
142 		return -EINVAL;
143 	}
144 
145 	/* Write the capture config; this also clears the capture counter */
146 	err = mv88e6xxx_tai_write(chip, MV88E6XXX_TAI_EVENT_STATUS,
147 				  cap_config);
148 
149 	return err;
150 }
151 
152 static void mv88e6352_tai_event_work(struct work_struct *ugly)
153 {
154 	struct delayed_work *dw = to_delayed_work(ugly);
155 	struct mv88e6xxx_chip *chip = dw_tai_event_to_chip(dw);
156 	struct ptp_clock_event ev;
157 	u16 status[4];
158 	u32 raw_ts;
159 	int err;
160 
161 	mv88e6xxx_reg_lock(chip);
162 	err = mv88e6xxx_tai_read(chip, MV88E6XXX_TAI_EVENT_STATUS,
163 				 status, ARRAY_SIZE(status));
164 	mv88e6xxx_reg_unlock(chip);
165 
166 	if (err) {
167 		dev_err(chip->dev, "failed to read TAI status register\n");
168 		return;
169 	}
170 	if (status[0] & MV88E6XXX_TAI_EVENT_STATUS_ERROR) {
171 		dev_warn(chip->dev, "missed event capture\n");
172 		return;
173 	}
174 	if (!(status[0] & MV88E6XXX_TAI_EVENT_STATUS_VALID))
175 		goto out;
176 
177 	raw_ts = ((u32)status[2] << 16) | status[1];
178 
179 	/* Clear the valid bit so the next timestamp can come in */
180 	status[0] &= ~MV88E6XXX_TAI_EVENT_STATUS_VALID;
181 	mv88e6xxx_reg_lock(chip);
182 	err = mv88e6xxx_tai_write(chip, MV88E6XXX_TAI_EVENT_STATUS, status[0]);
183 	mv88e6xxx_reg_unlock(chip);
184 
185 	/* This is an external timestamp */
186 	ev.type = PTP_CLOCK_EXTTS;
187 
188 	/* We only have one timestamping channel. */
189 	ev.index = 0;
190 	mv88e6xxx_reg_lock(chip);
191 	ev.timestamp = timecounter_cyc2time(&chip->tstamp_tc, raw_ts);
192 	mv88e6xxx_reg_unlock(chip);
193 
194 	ptp_clock_event(chip->ptp_clock, &ev);
195 out:
196 	schedule_delayed_work(&chip->tai_event_work, TAI_EVENT_WORK_INTERVAL);
197 }
198 
199 static int mv88e6xxx_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
200 {
201 	struct mv88e6xxx_chip *chip = ptp_to_chip(ptp);
202 	const struct mv88e6xxx_ptp_ops *ptp_ops = chip->info->ops->ptp_ops;
203 	int neg_adj = 0;
204 	u32 diff, mult;
205 	u64 adj;
206 
207 	if (scaled_ppm < 0) {
208 		neg_adj = 1;
209 		scaled_ppm = -scaled_ppm;
210 	}
211 
212 	mult = ptp_ops->cc_mult;
213 	adj = ptp_ops->cc_mult_num;
214 	adj *= scaled_ppm;
215 	diff = div_u64(adj, ptp_ops->cc_mult_dem);
216 
217 	mv88e6xxx_reg_lock(chip);
218 
219 	timecounter_read(&chip->tstamp_tc);
220 	chip->tstamp_cc.mult = neg_adj ? mult - diff : mult + diff;
221 
222 	mv88e6xxx_reg_unlock(chip);
223 
224 	return 0;
225 }
226 
227 static int mv88e6xxx_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
228 {
229 	struct mv88e6xxx_chip *chip = ptp_to_chip(ptp);
230 
231 	mv88e6xxx_reg_lock(chip);
232 	timecounter_adjtime(&chip->tstamp_tc, delta);
233 	mv88e6xxx_reg_unlock(chip);
234 
235 	return 0;
236 }
237 
238 static int mv88e6xxx_ptp_gettime(struct ptp_clock_info *ptp,
239 				 struct timespec64 *ts)
240 {
241 	struct mv88e6xxx_chip *chip = ptp_to_chip(ptp);
242 	u64 ns;
243 
244 	mv88e6xxx_reg_lock(chip);
245 	ns = timecounter_read(&chip->tstamp_tc);
246 	mv88e6xxx_reg_unlock(chip);
247 
248 	*ts = ns_to_timespec64(ns);
249 
250 	return 0;
251 }
252 
253 static int mv88e6xxx_ptp_settime(struct ptp_clock_info *ptp,
254 				 const struct timespec64 *ts)
255 {
256 	struct mv88e6xxx_chip *chip = ptp_to_chip(ptp);
257 	u64 ns;
258 
259 	ns = timespec64_to_ns(ts);
260 
261 	mv88e6xxx_reg_lock(chip);
262 	timecounter_init(&chip->tstamp_tc, &chip->tstamp_cc, ns);
263 	mv88e6xxx_reg_unlock(chip);
264 
265 	return 0;
266 }
267 
268 static int mv88e6352_ptp_enable_extts(struct mv88e6xxx_chip *chip,
269 				      struct ptp_clock_request *rq, int on)
270 {
271 	int rising = (rq->extts.flags & PTP_RISING_EDGE);
272 	int func;
273 	int pin;
274 	int err;
275 
276 	/* Reject requests with unsupported flags */
277 	if (rq->extts.flags & ~(PTP_ENABLE_FEATURE |
278 				PTP_RISING_EDGE |
279 				PTP_FALLING_EDGE |
280 				PTP_STRICT_FLAGS))
281 		return -EOPNOTSUPP;
282 
283 	/* Reject requests to enable time stamping on both edges. */
284 	if ((rq->extts.flags & PTP_STRICT_FLAGS) &&
285 	    (rq->extts.flags & PTP_ENABLE_FEATURE) &&
286 	    (rq->extts.flags & PTP_EXTTS_EDGES) == PTP_EXTTS_EDGES)
287 		return -EOPNOTSUPP;
288 
289 	pin = ptp_find_pin(chip->ptp_clock, PTP_PF_EXTTS, rq->extts.index);
290 
291 	if (pin < 0)
292 		return -EBUSY;
293 
294 	mv88e6xxx_reg_lock(chip);
295 
296 	if (on) {
297 		func = MV88E6352_G2_SCRATCH_GPIO_PCTL_EVREQ;
298 
299 		err = mv88e6352_set_gpio_func(chip, pin, func, true);
300 		if (err)
301 			goto out;
302 
303 		schedule_delayed_work(&chip->tai_event_work,
304 				      TAI_EVENT_WORK_INTERVAL);
305 
306 		err = mv88e6352_config_eventcap(chip, PTP_CLOCK_EXTTS, rising);
307 	} else {
308 		func = MV88E6352_G2_SCRATCH_GPIO_PCTL_GPIO;
309 
310 		err = mv88e6352_set_gpio_func(chip, pin, func, true);
311 
312 		cancel_delayed_work_sync(&chip->tai_event_work);
313 	}
314 
315 out:
316 	mv88e6xxx_reg_unlock(chip);
317 
318 	return err;
319 }
320 
321 static int mv88e6352_ptp_enable(struct ptp_clock_info *ptp,
322 				struct ptp_clock_request *rq, int on)
323 {
324 	struct mv88e6xxx_chip *chip = ptp_to_chip(ptp);
325 
326 	switch (rq->type) {
327 	case PTP_CLK_REQ_EXTTS:
328 		return mv88e6352_ptp_enable_extts(chip, rq, on);
329 	default:
330 		return -EOPNOTSUPP;
331 	}
332 }
333 
334 static int mv88e6352_ptp_verify(struct ptp_clock_info *ptp, unsigned int pin,
335 				enum ptp_pin_function func, unsigned int chan)
336 {
337 	switch (func) {
338 	case PTP_PF_NONE:
339 	case PTP_PF_EXTTS:
340 		break;
341 	case PTP_PF_PEROUT:
342 	case PTP_PF_PHYSYNC:
343 		return -EOPNOTSUPP;
344 	}
345 	return 0;
346 }
347 
348 const struct mv88e6xxx_ptp_ops mv88e6165_ptp_ops = {
349 	.clock_read = mv88e6165_ptp_clock_read,
350 	.global_enable = mv88e6165_global_enable,
351 	.global_disable = mv88e6165_global_disable,
352 	.arr0_sts_reg = MV88E6165_PORT_PTP_ARR0_STS,
353 	.arr1_sts_reg = MV88E6165_PORT_PTP_ARR1_STS,
354 	.dep_sts_reg = MV88E6165_PORT_PTP_DEP_STS,
355 	.rx_filters = (1 << HWTSTAMP_FILTER_NONE) |
356 		(1 << HWTSTAMP_FILTER_PTP_V2_L2_EVENT) |
357 		(1 << HWTSTAMP_FILTER_PTP_V2_L2_SYNC) |
358 		(1 << HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ) |
359 		(1 << HWTSTAMP_FILTER_PTP_V2_EVENT) |
360 		(1 << HWTSTAMP_FILTER_PTP_V2_SYNC) |
361 		(1 << HWTSTAMP_FILTER_PTP_V2_DELAY_REQ),
362 	.cc_shift = MV88E6XXX_CC_SHIFT,
363 	.cc_mult = MV88E6XXX_CC_MULT,
364 	.cc_mult_num = MV88E6XXX_CC_MULT_NUM,
365 	.cc_mult_dem = MV88E6XXX_CC_MULT_DEM,
366 };
367 
368 const struct mv88e6xxx_ptp_ops mv88e6250_ptp_ops = {
369 	.clock_read = mv88e6352_ptp_clock_read,
370 	.ptp_enable = mv88e6352_ptp_enable,
371 	.ptp_verify = mv88e6352_ptp_verify,
372 	.event_work = mv88e6352_tai_event_work,
373 	.port_enable = mv88e6352_hwtstamp_port_enable,
374 	.port_disable = mv88e6352_hwtstamp_port_disable,
375 	.n_ext_ts = 1,
376 	.arr0_sts_reg = MV88E6XXX_PORT_PTP_ARR0_STS,
377 	.arr1_sts_reg = MV88E6XXX_PORT_PTP_ARR1_STS,
378 	.dep_sts_reg = MV88E6XXX_PORT_PTP_DEP_STS,
379 	.rx_filters = (1 << HWTSTAMP_FILTER_NONE) |
380 		(1 << HWTSTAMP_FILTER_PTP_V2_L4_EVENT) |
381 		(1 << HWTSTAMP_FILTER_PTP_V2_L4_SYNC) |
382 		(1 << HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ) |
383 		(1 << HWTSTAMP_FILTER_PTP_V2_L2_EVENT) |
384 		(1 << HWTSTAMP_FILTER_PTP_V2_L2_SYNC) |
385 		(1 << HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ) |
386 		(1 << HWTSTAMP_FILTER_PTP_V2_EVENT) |
387 		(1 << HWTSTAMP_FILTER_PTP_V2_SYNC) |
388 		(1 << HWTSTAMP_FILTER_PTP_V2_DELAY_REQ),
389 	.cc_shift = MV88E6250_CC_SHIFT,
390 	.cc_mult = MV88E6250_CC_MULT,
391 	.cc_mult_num = MV88E6250_CC_MULT_NUM,
392 	.cc_mult_dem = MV88E6250_CC_MULT_DEM,
393 };
394 
395 const struct mv88e6xxx_ptp_ops mv88e6352_ptp_ops = {
396 	.clock_read = mv88e6352_ptp_clock_read,
397 	.ptp_enable = mv88e6352_ptp_enable,
398 	.ptp_verify = mv88e6352_ptp_verify,
399 	.event_work = mv88e6352_tai_event_work,
400 	.port_enable = mv88e6352_hwtstamp_port_enable,
401 	.port_disable = mv88e6352_hwtstamp_port_disable,
402 	.n_ext_ts = 1,
403 	.arr0_sts_reg = MV88E6XXX_PORT_PTP_ARR0_STS,
404 	.arr1_sts_reg = MV88E6XXX_PORT_PTP_ARR1_STS,
405 	.dep_sts_reg = MV88E6XXX_PORT_PTP_DEP_STS,
406 	.rx_filters = (1 << HWTSTAMP_FILTER_NONE) |
407 		(1 << HWTSTAMP_FILTER_PTP_V2_L4_EVENT) |
408 		(1 << HWTSTAMP_FILTER_PTP_V2_L4_SYNC) |
409 		(1 << HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ) |
410 		(1 << HWTSTAMP_FILTER_PTP_V2_L2_EVENT) |
411 		(1 << HWTSTAMP_FILTER_PTP_V2_L2_SYNC) |
412 		(1 << HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ) |
413 		(1 << HWTSTAMP_FILTER_PTP_V2_EVENT) |
414 		(1 << HWTSTAMP_FILTER_PTP_V2_SYNC) |
415 		(1 << HWTSTAMP_FILTER_PTP_V2_DELAY_REQ),
416 	.cc_shift = MV88E6XXX_CC_SHIFT,
417 	.cc_mult = MV88E6XXX_CC_MULT,
418 	.cc_mult_num = MV88E6XXX_CC_MULT_NUM,
419 	.cc_mult_dem = MV88E6XXX_CC_MULT_DEM,
420 };
421 
422 static u64 mv88e6xxx_ptp_clock_read(const struct cyclecounter *cc)
423 {
424 	struct mv88e6xxx_chip *chip = cc_to_chip(cc);
425 
426 	if (chip->info->ops->ptp_ops->clock_read)
427 		return chip->info->ops->ptp_ops->clock_read(cc);
428 
429 	return 0;
430 }
431 
432 /* With a 125MHz input clock, the 32-bit timestamp counter overflows in ~34.3
433  * seconds; this task forces periodic reads so that we don't miss any.
434  */
435 #define MV88E6XXX_TAI_OVERFLOW_PERIOD (HZ * 16)
436 static void mv88e6xxx_ptp_overflow_check(struct work_struct *work)
437 {
438 	struct delayed_work *dw = to_delayed_work(work);
439 	struct mv88e6xxx_chip *chip = dw_overflow_to_chip(dw);
440 	struct timespec64 ts;
441 
442 	mv88e6xxx_ptp_gettime(&chip->ptp_clock_info, &ts);
443 
444 	schedule_delayed_work(&chip->overflow_work,
445 			      MV88E6XXX_TAI_OVERFLOW_PERIOD);
446 }
447 
448 int mv88e6xxx_ptp_setup(struct mv88e6xxx_chip *chip)
449 {
450 	const struct mv88e6xxx_ptp_ops *ptp_ops = chip->info->ops->ptp_ops;
451 	int i;
452 
453 	/* Set up the cycle counter */
454 	memset(&chip->tstamp_cc, 0, sizeof(chip->tstamp_cc));
455 	chip->tstamp_cc.read	= mv88e6xxx_ptp_clock_read;
456 	chip->tstamp_cc.mask	= CYCLECOUNTER_MASK(32);
457 	chip->tstamp_cc.mult	= ptp_ops->cc_mult;
458 	chip->tstamp_cc.shift	= ptp_ops->cc_shift;
459 
460 	timecounter_init(&chip->tstamp_tc, &chip->tstamp_cc,
461 			 ktime_to_ns(ktime_get_real()));
462 
463 	INIT_DELAYED_WORK(&chip->overflow_work, mv88e6xxx_ptp_overflow_check);
464 	if (ptp_ops->event_work)
465 		INIT_DELAYED_WORK(&chip->tai_event_work, ptp_ops->event_work);
466 
467 	chip->ptp_clock_info.owner = THIS_MODULE;
468 	snprintf(chip->ptp_clock_info.name, sizeof(chip->ptp_clock_info.name),
469 		 "%s", dev_name(chip->dev));
470 
471 	chip->ptp_clock_info.n_ext_ts	= ptp_ops->n_ext_ts;
472 	chip->ptp_clock_info.n_per_out	= 0;
473 	chip->ptp_clock_info.n_pins	= mv88e6xxx_num_gpio(chip);
474 	chip->ptp_clock_info.pps	= 0;
475 
476 	for (i = 0; i < chip->ptp_clock_info.n_pins; ++i) {
477 		struct ptp_pin_desc *ppd = &chip->pin_config[i];
478 
479 		snprintf(ppd->name, sizeof(ppd->name), "mv88e6xxx_gpio%d", i);
480 		ppd->index = i;
481 		ppd->func = PTP_PF_NONE;
482 	}
483 	chip->ptp_clock_info.pin_config = chip->pin_config;
484 
485 	chip->ptp_clock_info.max_adj    = MV88E6XXX_MAX_ADJ_PPB;
486 	chip->ptp_clock_info.adjfine	= mv88e6xxx_ptp_adjfine;
487 	chip->ptp_clock_info.adjtime	= mv88e6xxx_ptp_adjtime;
488 	chip->ptp_clock_info.gettime64	= mv88e6xxx_ptp_gettime;
489 	chip->ptp_clock_info.settime64	= mv88e6xxx_ptp_settime;
490 	chip->ptp_clock_info.enable	= ptp_ops->ptp_enable;
491 	chip->ptp_clock_info.verify	= ptp_ops->ptp_verify;
492 	chip->ptp_clock_info.do_aux_work = mv88e6xxx_hwtstamp_work;
493 
494 	chip->ptp_clock = ptp_clock_register(&chip->ptp_clock_info, chip->dev);
495 	if (IS_ERR(chip->ptp_clock))
496 		return PTR_ERR(chip->ptp_clock);
497 
498 	schedule_delayed_work(&chip->overflow_work,
499 			      MV88E6XXX_TAI_OVERFLOW_PERIOD);
500 
501 	return 0;
502 }
503 
504 void mv88e6xxx_ptp_free(struct mv88e6xxx_chip *chip)
505 {
506 	if (chip->ptp_clock) {
507 		cancel_delayed_work_sync(&chip->overflow_work);
508 		if (chip->info->ops->ptp_ops->event_work)
509 			cancel_delayed_work_sync(&chip->tai_event_work);
510 
511 		ptp_clock_unregister(chip->ptp_clock);
512 		chip->ptp_clock = NULL;
513 	}
514 }
515