xref: /openbmc/linux/drivers/net/dsa/mv88e6xxx/ptp.c (revision b830f94f)
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 /* Raw timestamps are in units of 8-ns clock periods. */
19 #define CC_SHIFT	28
20 #define CC_MULT		(8 << CC_SHIFT)
21 #define CC_MULT_NUM	(1 << 9)
22 #define CC_MULT_DEM	15625ULL
23 
24 #define TAI_EVENT_WORK_INTERVAL msecs_to_jiffies(100)
25 
26 #define cc_to_chip(cc) container_of(cc, struct mv88e6xxx_chip, tstamp_cc)
27 #define dw_overflow_to_chip(dw) container_of(dw, struct mv88e6xxx_chip, \
28 					     overflow_work)
29 #define dw_tai_event_to_chip(dw) container_of(dw, struct mv88e6xxx_chip, \
30 					      tai_event_work)
31 
32 static int mv88e6xxx_tai_read(struct mv88e6xxx_chip *chip, int addr,
33 			      u16 *data, int len)
34 {
35 	if (!chip->info->ops->avb_ops->tai_read)
36 		return -EOPNOTSUPP;
37 
38 	return chip->info->ops->avb_ops->tai_read(chip, addr, data, len);
39 }
40 
41 static int mv88e6xxx_tai_write(struct mv88e6xxx_chip *chip, int addr, u16 data)
42 {
43 	if (!chip->info->ops->avb_ops->tai_write)
44 		return -EOPNOTSUPP;
45 
46 	return chip->info->ops->avb_ops->tai_write(chip, addr, data);
47 }
48 
49 /* TODO: places where this are called should be using pinctrl */
50 static int mv88e6352_set_gpio_func(struct mv88e6xxx_chip *chip, int pin,
51 				   int func, int input)
52 {
53 	int err;
54 
55 	if (!chip->info->ops->gpio_ops)
56 		return -EOPNOTSUPP;
57 
58 	err = chip->info->ops->gpio_ops->set_dir(chip, pin, input);
59 	if (err)
60 		return err;
61 
62 	return chip->info->ops->gpio_ops->set_pctl(chip, pin, func);
63 }
64 
65 static u64 mv88e6352_ptp_clock_read(const struct cyclecounter *cc)
66 {
67 	struct mv88e6xxx_chip *chip = cc_to_chip(cc);
68 	u16 phc_time[2];
69 	int err;
70 
71 	err = mv88e6xxx_tai_read(chip, MV88E6XXX_TAI_TIME_LO, phc_time,
72 				 ARRAY_SIZE(phc_time));
73 	if (err)
74 		return 0;
75 	else
76 		return ((u32)phc_time[1] << 16) | phc_time[0];
77 }
78 
79 static u64 mv88e6165_ptp_clock_read(const struct cyclecounter *cc)
80 {
81 	struct mv88e6xxx_chip *chip = cc_to_chip(cc);
82 	u16 phc_time[2];
83 	int err;
84 
85 	err = mv88e6xxx_tai_read(chip, MV88E6XXX_PTP_GC_TIME_LO, phc_time,
86 				 ARRAY_SIZE(phc_time));
87 	if (err)
88 		return 0;
89 	else
90 		return ((u32)phc_time[1] << 16) | phc_time[0];
91 }
92 
93 /* mv88e6352_config_eventcap - configure TAI event capture
94  * @event: PTP_CLOCK_PPS (internal) or PTP_CLOCK_EXTTS (external)
95  * @rising: zero for falling-edge trigger, else rising-edge trigger
96  *
97  * This will also reset the capture sequence counter.
98  */
99 static int mv88e6352_config_eventcap(struct mv88e6xxx_chip *chip, int event,
100 				     int rising)
101 {
102 	u16 global_config;
103 	u16 cap_config;
104 	int err;
105 
106 	chip->evcap_config = MV88E6XXX_TAI_CFG_CAP_OVERWRITE |
107 			     MV88E6XXX_TAI_CFG_CAP_CTR_START;
108 	if (!rising)
109 		chip->evcap_config |= MV88E6XXX_TAI_CFG_EVREQ_FALLING;
110 
111 	global_config = (chip->evcap_config | chip->trig_config);
112 	err = mv88e6xxx_tai_write(chip, MV88E6XXX_TAI_CFG, global_config);
113 	if (err)
114 		return err;
115 
116 	if (event == PTP_CLOCK_PPS) {
117 		cap_config = MV88E6XXX_TAI_EVENT_STATUS_CAP_TRIG;
118 	} else if (event == PTP_CLOCK_EXTTS) {
119 		/* if STATUS_CAP_TRIG is unset we capture PTP_EVREQ events */
120 		cap_config = 0;
121 	} else {
122 		return -EINVAL;
123 	}
124 
125 	/* Write the capture config; this also clears the capture counter */
126 	err = mv88e6xxx_tai_write(chip, MV88E6XXX_TAI_EVENT_STATUS,
127 				  cap_config);
128 
129 	return err;
130 }
131 
132 static void mv88e6352_tai_event_work(struct work_struct *ugly)
133 {
134 	struct delayed_work *dw = to_delayed_work(ugly);
135 	struct mv88e6xxx_chip *chip = dw_tai_event_to_chip(dw);
136 	struct ptp_clock_event ev;
137 	u16 status[4];
138 	u32 raw_ts;
139 	int err;
140 
141 	mv88e6xxx_reg_lock(chip);
142 	err = mv88e6xxx_tai_read(chip, MV88E6XXX_TAI_EVENT_STATUS,
143 				 status, ARRAY_SIZE(status));
144 	mv88e6xxx_reg_unlock(chip);
145 
146 	if (err) {
147 		dev_err(chip->dev, "failed to read TAI status register\n");
148 		return;
149 	}
150 	if (status[0] & MV88E6XXX_TAI_EVENT_STATUS_ERROR) {
151 		dev_warn(chip->dev, "missed event capture\n");
152 		return;
153 	}
154 	if (!(status[0] & MV88E6XXX_TAI_EVENT_STATUS_VALID))
155 		goto out;
156 
157 	raw_ts = ((u32)status[2] << 16) | status[1];
158 
159 	/* Clear the valid bit so the next timestamp can come in */
160 	status[0] &= ~MV88E6XXX_TAI_EVENT_STATUS_VALID;
161 	mv88e6xxx_reg_lock(chip);
162 	err = mv88e6xxx_tai_write(chip, MV88E6XXX_TAI_EVENT_STATUS, status[0]);
163 	mv88e6xxx_reg_unlock(chip);
164 
165 	/* This is an external timestamp */
166 	ev.type = PTP_CLOCK_EXTTS;
167 
168 	/* We only have one timestamping channel. */
169 	ev.index = 0;
170 	mv88e6xxx_reg_lock(chip);
171 	ev.timestamp = timecounter_cyc2time(&chip->tstamp_tc, raw_ts);
172 	mv88e6xxx_reg_unlock(chip);
173 
174 	ptp_clock_event(chip->ptp_clock, &ev);
175 out:
176 	schedule_delayed_work(&chip->tai_event_work, TAI_EVENT_WORK_INTERVAL);
177 }
178 
179 static int mv88e6xxx_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
180 {
181 	struct mv88e6xxx_chip *chip = ptp_to_chip(ptp);
182 	int neg_adj = 0;
183 	u32 diff, mult;
184 	u64 adj;
185 
186 	if (scaled_ppm < 0) {
187 		neg_adj = 1;
188 		scaled_ppm = -scaled_ppm;
189 	}
190 	mult = CC_MULT;
191 	adj = CC_MULT_NUM;
192 	adj *= scaled_ppm;
193 	diff = div_u64(adj, CC_MULT_DEM);
194 
195 	mv88e6xxx_reg_lock(chip);
196 
197 	timecounter_read(&chip->tstamp_tc);
198 	chip->tstamp_cc.mult = neg_adj ? mult - diff : mult + diff;
199 
200 	mv88e6xxx_reg_unlock(chip);
201 
202 	return 0;
203 }
204 
205 static int mv88e6xxx_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
206 {
207 	struct mv88e6xxx_chip *chip = ptp_to_chip(ptp);
208 
209 	mv88e6xxx_reg_lock(chip);
210 	timecounter_adjtime(&chip->tstamp_tc, delta);
211 	mv88e6xxx_reg_unlock(chip);
212 
213 	return 0;
214 }
215 
216 static int mv88e6xxx_ptp_gettime(struct ptp_clock_info *ptp,
217 				 struct timespec64 *ts)
218 {
219 	struct mv88e6xxx_chip *chip = ptp_to_chip(ptp);
220 	u64 ns;
221 
222 	mv88e6xxx_reg_lock(chip);
223 	ns = timecounter_read(&chip->tstamp_tc);
224 	mv88e6xxx_reg_unlock(chip);
225 
226 	*ts = ns_to_timespec64(ns);
227 
228 	return 0;
229 }
230 
231 static int mv88e6xxx_ptp_settime(struct ptp_clock_info *ptp,
232 				 const struct timespec64 *ts)
233 {
234 	struct mv88e6xxx_chip *chip = ptp_to_chip(ptp);
235 	u64 ns;
236 
237 	ns = timespec64_to_ns(ts);
238 
239 	mv88e6xxx_reg_lock(chip);
240 	timecounter_init(&chip->tstamp_tc, &chip->tstamp_cc, ns);
241 	mv88e6xxx_reg_unlock(chip);
242 
243 	return 0;
244 }
245 
246 static int mv88e6352_ptp_enable_extts(struct mv88e6xxx_chip *chip,
247 				      struct ptp_clock_request *rq, int on)
248 {
249 	int rising = (rq->extts.flags & PTP_RISING_EDGE);
250 	int func;
251 	int pin;
252 	int err;
253 
254 	pin = ptp_find_pin(chip->ptp_clock, PTP_PF_EXTTS, rq->extts.index);
255 
256 	if (pin < 0)
257 		return -EBUSY;
258 
259 	mv88e6xxx_reg_lock(chip);
260 
261 	if (on) {
262 		func = MV88E6352_G2_SCRATCH_GPIO_PCTL_EVREQ;
263 
264 		err = mv88e6352_set_gpio_func(chip, pin, func, true);
265 		if (err)
266 			goto out;
267 
268 		schedule_delayed_work(&chip->tai_event_work,
269 				      TAI_EVENT_WORK_INTERVAL);
270 
271 		err = mv88e6352_config_eventcap(chip, PTP_CLOCK_EXTTS, rising);
272 	} else {
273 		func = MV88E6352_G2_SCRATCH_GPIO_PCTL_GPIO;
274 
275 		err = mv88e6352_set_gpio_func(chip, pin, func, true);
276 
277 		cancel_delayed_work_sync(&chip->tai_event_work);
278 	}
279 
280 out:
281 	mv88e6xxx_reg_unlock(chip);
282 
283 	return err;
284 }
285 
286 static int mv88e6352_ptp_enable(struct ptp_clock_info *ptp,
287 				struct ptp_clock_request *rq, int on)
288 {
289 	struct mv88e6xxx_chip *chip = ptp_to_chip(ptp);
290 
291 	switch (rq->type) {
292 	case PTP_CLK_REQ_EXTTS:
293 		return mv88e6352_ptp_enable_extts(chip, rq, on);
294 	default:
295 		return -EOPNOTSUPP;
296 	}
297 }
298 
299 static int mv88e6352_ptp_verify(struct ptp_clock_info *ptp, unsigned int pin,
300 				enum ptp_pin_function func, unsigned int chan)
301 {
302 	switch (func) {
303 	case PTP_PF_NONE:
304 	case PTP_PF_EXTTS:
305 		break;
306 	case PTP_PF_PEROUT:
307 	case PTP_PF_PHYSYNC:
308 		return -EOPNOTSUPP;
309 	}
310 	return 0;
311 }
312 
313 const struct mv88e6xxx_ptp_ops mv88e6352_ptp_ops = {
314 	.clock_read = mv88e6352_ptp_clock_read,
315 	.ptp_enable = mv88e6352_ptp_enable,
316 	.ptp_verify = mv88e6352_ptp_verify,
317 	.event_work = mv88e6352_tai_event_work,
318 	.port_enable = mv88e6352_hwtstamp_port_enable,
319 	.port_disable = mv88e6352_hwtstamp_port_disable,
320 	.n_ext_ts = 1,
321 	.arr0_sts_reg = MV88E6XXX_PORT_PTP_ARR0_STS,
322 	.arr1_sts_reg = MV88E6XXX_PORT_PTP_ARR1_STS,
323 	.dep_sts_reg = MV88E6XXX_PORT_PTP_DEP_STS,
324 	.rx_filters = (1 << HWTSTAMP_FILTER_NONE) |
325 		(1 << HWTSTAMP_FILTER_PTP_V2_L4_EVENT) |
326 		(1 << HWTSTAMP_FILTER_PTP_V2_L4_SYNC) |
327 		(1 << HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ) |
328 		(1 << HWTSTAMP_FILTER_PTP_V2_L2_EVENT) |
329 		(1 << HWTSTAMP_FILTER_PTP_V2_L2_SYNC) |
330 		(1 << HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ) |
331 		(1 << HWTSTAMP_FILTER_PTP_V2_EVENT) |
332 		(1 << HWTSTAMP_FILTER_PTP_V2_SYNC) |
333 		(1 << HWTSTAMP_FILTER_PTP_V2_DELAY_REQ),
334 };
335 
336 const struct mv88e6xxx_ptp_ops mv88e6165_ptp_ops = {
337 	.clock_read = mv88e6165_ptp_clock_read,
338 	.global_enable = mv88e6165_global_enable,
339 	.global_disable = mv88e6165_global_disable,
340 	.arr0_sts_reg = MV88E6165_PORT_PTP_ARR0_STS,
341 	.arr1_sts_reg = MV88E6165_PORT_PTP_ARR1_STS,
342 	.dep_sts_reg = MV88E6165_PORT_PTP_DEP_STS,
343 	.rx_filters = (1 << HWTSTAMP_FILTER_NONE) |
344 		(1 << HWTSTAMP_FILTER_PTP_V2_L2_EVENT) |
345 		(1 << HWTSTAMP_FILTER_PTP_V2_L2_SYNC) |
346 		(1 << HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ) |
347 		(1 << HWTSTAMP_FILTER_PTP_V2_EVENT) |
348 		(1 << HWTSTAMP_FILTER_PTP_V2_SYNC) |
349 		(1 << HWTSTAMP_FILTER_PTP_V2_DELAY_REQ),
350 };
351 
352 static u64 mv88e6xxx_ptp_clock_read(const struct cyclecounter *cc)
353 {
354 	struct mv88e6xxx_chip *chip = cc_to_chip(cc);
355 
356 	if (chip->info->ops->ptp_ops->clock_read)
357 		return chip->info->ops->ptp_ops->clock_read(cc);
358 
359 	return 0;
360 }
361 
362 /* With a 125MHz input clock, the 32-bit timestamp counter overflows in ~34.3
363  * seconds; this task forces periodic reads so that we don't miss any.
364  */
365 #define MV88E6XXX_TAI_OVERFLOW_PERIOD (HZ * 16)
366 static void mv88e6xxx_ptp_overflow_check(struct work_struct *work)
367 {
368 	struct delayed_work *dw = to_delayed_work(work);
369 	struct mv88e6xxx_chip *chip = dw_overflow_to_chip(dw);
370 	struct timespec64 ts;
371 
372 	mv88e6xxx_ptp_gettime(&chip->ptp_clock_info, &ts);
373 
374 	schedule_delayed_work(&chip->overflow_work,
375 			      MV88E6XXX_TAI_OVERFLOW_PERIOD);
376 }
377 
378 int mv88e6xxx_ptp_setup(struct mv88e6xxx_chip *chip)
379 {
380 	const struct mv88e6xxx_ptp_ops *ptp_ops = chip->info->ops->ptp_ops;
381 	int i;
382 
383 	/* Set up the cycle counter */
384 	memset(&chip->tstamp_cc, 0, sizeof(chip->tstamp_cc));
385 	chip->tstamp_cc.read	= mv88e6xxx_ptp_clock_read;
386 	chip->tstamp_cc.mask	= CYCLECOUNTER_MASK(32);
387 	chip->tstamp_cc.mult	= CC_MULT;
388 	chip->tstamp_cc.shift	= CC_SHIFT;
389 
390 	timecounter_init(&chip->tstamp_tc, &chip->tstamp_cc,
391 			 ktime_to_ns(ktime_get_real()));
392 
393 	INIT_DELAYED_WORK(&chip->overflow_work, mv88e6xxx_ptp_overflow_check);
394 	if (ptp_ops->event_work)
395 		INIT_DELAYED_WORK(&chip->tai_event_work, ptp_ops->event_work);
396 
397 	chip->ptp_clock_info.owner = THIS_MODULE;
398 	snprintf(chip->ptp_clock_info.name, sizeof(chip->ptp_clock_info.name),
399 		 "%s", dev_name(chip->dev));
400 	chip->ptp_clock_info.max_adj	= 1000000;
401 
402 	chip->ptp_clock_info.n_ext_ts	= ptp_ops->n_ext_ts;
403 	chip->ptp_clock_info.n_per_out	= 0;
404 	chip->ptp_clock_info.n_pins	= mv88e6xxx_num_gpio(chip);
405 	chip->ptp_clock_info.pps	= 0;
406 
407 	for (i = 0; i < chip->ptp_clock_info.n_pins; ++i) {
408 		struct ptp_pin_desc *ppd = &chip->pin_config[i];
409 
410 		snprintf(ppd->name, sizeof(ppd->name), "mv88e6xxx_gpio%d", i);
411 		ppd->index = i;
412 		ppd->func = PTP_PF_NONE;
413 	}
414 	chip->ptp_clock_info.pin_config = chip->pin_config;
415 
416 	chip->ptp_clock_info.adjfine	= mv88e6xxx_ptp_adjfine;
417 	chip->ptp_clock_info.adjtime	= mv88e6xxx_ptp_adjtime;
418 	chip->ptp_clock_info.gettime64	= mv88e6xxx_ptp_gettime;
419 	chip->ptp_clock_info.settime64	= mv88e6xxx_ptp_settime;
420 	chip->ptp_clock_info.enable	= ptp_ops->ptp_enable;
421 	chip->ptp_clock_info.verify	= ptp_ops->ptp_verify;
422 	chip->ptp_clock_info.do_aux_work = mv88e6xxx_hwtstamp_work;
423 
424 	chip->ptp_clock = ptp_clock_register(&chip->ptp_clock_info, chip->dev);
425 	if (IS_ERR(chip->ptp_clock))
426 		return PTR_ERR(chip->ptp_clock);
427 
428 	schedule_delayed_work(&chip->overflow_work,
429 			      MV88E6XXX_TAI_OVERFLOW_PERIOD);
430 
431 	return 0;
432 }
433 
434 void mv88e6xxx_ptp_free(struct mv88e6xxx_chip *chip)
435 {
436 	if (chip->ptp_clock) {
437 		cancel_delayed_work_sync(&chip->overflow_work);
438 		if (chip->info->ops->ptp_ops->event_work)
439 			cancel_delayed_work_sync(&chip->tai_event_work);
440 
441 		ptp_clock_unregister(chip->ptp_clock);
442 		chip->ptp_clock = NULL;
443 	}
444 }
445