xref: /openbmc/linux/drivers/net/dsa/mv88e6xxx/ptp.c (revision 6d99a79c)
1 /*
2  * Marvell 88E6xxx Switch PTP support
3  *
4  * Copyright (c) 2008 Marvell Semiconductor
5  *
6  * Copyright (c) 2017 National Instruments
7  *      Erik Hons <erik.hons@ni.com>
8  *      Brandon Streiff <brandon.streiff@ni.com>
9  *      Dane Wagner <dane.wagner@ni.com>
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  */
16 
17 #include "chip.h"
18 #include "global2.h"
19 #include "hwtstamp.h"
20 #include "ptp.h"
21 
22 /* Raw timestamps are in units of 8-ns clock periods. */
23 #define CC_SHIFT	28
24 #define CC_MULT		(8 << CC_SHIFT)
25 #define CC_MULT_NUM	(1 << 9)
26 #define CC_MULT_DEM	15625ULL
27 
28 #define TAI_EVENT_WORK_INTERVAL msecs_to_jiffies(100)
29 
30 #define cc_to_chip(cc) container_of(cc, struct mv88e6xxx_chip, tstamp_cc)
31 #define dw_overflow_to_chip(dw) container_of(dw, struct mv88e6xxx_chip, \
32 					     overflow_work)
33 #define dw_tai_event_to_chip(dw) container_of(dw, struct mv88e6xxx_chip, \
34 					      tai_event_work)
35 
36 static int mv88e6xxx_tai_read(struct mv88e6xxx_chip *chip, int addr,
37 			      u16 *data, int len)
38 {
39 	if (!chip->info->ops->avb_ops->tai_read)
40 		return -EOPNOTSUPP;
41 
42 	return chip->info->ops->avb_ops->tai_read(chip, addr, data, len);
43 }
44 
45 static int mv88e6xxx_tai_write(struct mv88e6xxx_chip *chip, int addr, u16 data)
46 {
47 	if (!chip->info->ops->avb_ops->tai_write)
48 		return -EOPNOTSUPP;
49 
50 	return chip->info->ops->avb_ops->tai_write(chip, addr, data);
51 }
52 
53 /* TODO: places where this are called should be using pinctrl */
54 static int mv88e6352_set_gpio_func(struct mv88e6xxx_chip *chip, int pin,
55 				   int func, int input)
56 {
57 	int err;
58 
59 	if (!chip->info->ops->gpio_ops)
60 		return -EOPNOTSUPP;
61 
62 	err = chip->info->ops->gpio_ops->set_dir(chip, pin, input);
63 	if (err)
64 		return err;
65 
66 	return chip->info->ops->gpio_ops->set_pctl(chip, pin, func);
67 }
68 
69 static u64 mv88e6352_ptp_clock_read(const struct cyclecounter *cc)
70 {
71 	struct mv88e6xxx_chip *chip = cc_to_chip(cc);
72 	u16 phc_time[2];
73 	int err;
74 
75 	err = mv88e6xxx_tai_read(chip, MV88E6XXX_TAI_TIME_LO, phc_time,
76 				 ARRAY_SIZE(phc_time));
77 	if (err)
78 		return 0;
79 	else
80 		return ((u32)phc_time[1] << 16) | phc_time[0];
81 }
82 
83 static u64 mv88e6165_ptp_clock_read(const struct cyclecounter *cc)
84 {
85 	struct mv88e6xxx_chip *chip = cc_to_chip(cc);
86 	u16 phc_time[2];
87 	int err;
88 
89 	err = mv88e6xxx_tai_read(chip, MV88E6XXX_PTP_GC_TIME_LO, phc_time,
90 				 ARRAY_SIZE(phc_time));
91 	if (err)
92 		return 0;
93 	else
94 		return ((u32)phc_time[1] << 16) | phc_time[0];
95 }
96 
97 /* mv88e6352_config_eventcap - configure TAI event capture
98  * @event: PTP_CLOCK_PPS (internal) or PTP_CLOCK_EXTTS (external)
99  * @rising: zero for falling-edge trigger, else rising-edge trigger
100  *
101  * This will also reset the capture sequence counter.
102  */
103 static int mv88e6352_config_eventcap(struct mv88e6xxx_chip *chip, int event,
104 				     int rising)
105 {
106 	u16 global_config;
107 	u16 cap_config;
108 	int err;
109 
110 	chip->evcap_config = MV88E6XXX_TAI_CFG_CAP_OVERWRITE |
111 			     MV88E6XXX_TAI_CFG_CAP_CTR_START;
112 	if (!rising)
113 		chip->evcap_config |= MV88E6XXX_TAI_CFG_EVREQ_FALLING;
114 
115 	global_config = (chip->evcap_config | chip->trig_config);
116 	err = mv88e6xxx_tai_write(chip, MV88E6XXX_TAI_CFG, global_config);
117 	if (err)
118 		return err;
119 
120 	if (event == PTP_CLOCK_PPS) {
121 		cap_config = MV88E6XXX_TAI_EVENT_STATUS_CAP_TRIG;
122 	} else if (event == PTP_CLOCK_EXTTS) {
123 		/* if STATUS_CAP_TRIG is unset we capture PTP_EVREQ events */
124 		cap_config = 0;
125 	} else {
126 		return -EINVAL;
127 	}
128 
129 	/* Write the capture config; this also clears the capture counter */
130 	err = mv88e6xxx_tai_write(chip, MV88E6XXX_TAI_EVENT_STATUS,
131 				  cap_config);
132 
133 	return err;
134 }
135 
136 static void mv88e6352_tai_event_work(struct work_struct *ugly)
137 {
138 	struct delayed_work *dw = to_delayed_work(ugly);
139 	struct mv88e6xxx_chip *chip = dw_tai_event_to_chip(dw);
140 	struct ptp_clock_event ev;
141 	u16 status[4];
142 	u32 raw_ts;
143 	int err;
144 
145 	mutex_lock(&chip->reg_lock);
146 	err = mv88e6xxx_tai_read(chip, MV88E6XXX_TAI_EVENT_STATUS,
147 				 status, ARRAY_SIZE(status));
148 	mutex_unlock(&chip->reg_lock);
149 
150 	if (err) {
151 		dev_err(chip->dev, "failed to read TAI status register\n");
152 		return;
153 	}
154 	if (status[0] & MV88E6XXX_TAI_EVENT_STATUS_ERROR) {
155 		dev_warn(chip->dev, "missed event capture\n");
156 		return;
157 	}
158 	if (!(status[0] & MV88E6XXX_TAI_EVENT_STATUS_VALID))
159 		goto out;
160 
161 	raw_ts = ((u32)status[2] << 16) | status[1];
162 
163 	/* Clear the valid bit so the next timestamp can come in */
164 	status[0] &= ~MV88E6XXX_TAI_EVENT_STATUS_VALID;
165 	mutex_lock(&chip->reg_lock);
166 	err = mv88e6xxx_tai_write(chip, MV88E6XXX_TAI_EVENT_STATUS, status[0]);
167 	mutex_unlock(&chip->reg_lock);
168 
169 	/* This is an external timestamp */
170 	ev.type = PTP_CLOCK_EXTTS;
171 
172 	/* We only have one timestamping channel. */
173 	ev.index = 0;
174 	mutex_lock(&chip->reg_lock);
175 	ev.timestamp = timecounter_cyc2time(&chip->tstamp_tc, raw_ts);
176 	mutex_unlock(&chip->reg_lock);
177 
178 	ptp_clock_event(chip->ptp_clock, &ev);
179 out:
180 	schedule_delayed_work(&chip->tai_event_work, TAI_EVENT_WORK_INTERVAL);
181 }
182 
183 static int mv88e6xxx_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
184 {
185 	struct mv88e6xxx_chip *chip = ptp_to_chip(ptp);
186 	int neg_adj = 0;
187 	u32 diff, mult;
188 	u64 adj;
189 
190 	if (scaled_ppm < 0) {
191 		neg_adj = 1;
192 		scaled_ppm = -scaled_ppm;
193 	}
194 	mult = CC_MULT;
195 	adj = CC_MULT_NUM;
196 	adj *= scaled_ppm;
197 	diff = div_u64(adj, CC_MULT_DEM);
198 
199 	mutex_lock(&chip->reg_lock);
200 
201 	timecounter_read(&chip->tstamp_tc);
202 	chip->tstamp_cc.mult = neg_adj ? mult - diff : mult + diff;
203 
204 	mutex_unlock(&chip->reg_lock);
205 
206 	return 0;
207 }
208 
209 static int mv88e6xxx_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
210 {
211 	struct mv88e6xxx_chip *chip = ptp_to_chip(ptp);
212 
213 	mutex_lock(&chip->reg_lock);
214 	timecounter_adjtime(&chip->tstamp_tc, delta);
215 	mutex_unlock(&chip->reg_lock);
216 
217 	return 0;
218 }
219 
220 static int mv88e6xxx_ptp_gettime(struct ptp_clock_info *ptp,
221 				 struct timespec64 *ts)
222 {
223 	struct mv88e6xxx_chip *chip = ptp_to_chip(ptp);
224 	u64 ns;
225 
226 	mutex_lock(&chip->reg_lock);
227 	ns = timecounter_read(&chip->tstamp_tc);
228 	mutex_unlock(&chip->reg_lock);
229 
230 	*ts = ns_to_timespec64(ns);
231 
232 	return 0;
233 }
234 
235 static int mv88e6xxx_ptp_settime(struct ptp_clock_info *ptp,
236 				 const struct timespec64 *ts)
237 {
238 	struct mv88e6xxx_chip *chip = ptp_to_chip(ptp);
239 	u64 ns;
240 
241 	ns = timespec64_to_ns(ts);
242 
243 	mutex_lock(&chip->reg_lock);
244 	timecounter_init(&chip->tstamp_tc, &chip->tstamp_cc, ns);
245 	mutex_unlock(&chip->reg_lock);
246 
247 	return 0;
248 }
249 
250 static int mv88e6352_ptp_enable_extts(struct mv88e6xxx_chip *chip,
251 				      struct ptp_clock_request *rq, int on)
252 {
253 	int rising = (rq->extts.flags & PTP_RISING_EDGE);
254 	int func;
255 	int pin;
256 	int err;
257 
258 	pin = ptp_find_pin(chip->ptp_clock, PTP_PF_EXTTS, rq->extts.index);
259 
260 	if (pin < 0)
261 		return -EBUSY;
262 
263 	mutex_lock(&chip->reg_lock);
264 
265 	if (on) {
266 		func = MV88E6352_G2_SCRATCH_GPIO_PCTL_EVREQ;
267 
268 		err = mv88e6352_set_gpio_func(chip, pin, func, true);
269 		if (err)
270 			goto out;
271 
272 		schedule_delayed_work(&chip->tai_event_work,
273 				      TAI_EVENT_WORK_INTERVAL);
274 
275 		err = mv88e6352_config_eventcap(chip, PTP_CLOCK_EXTTS, rising);
276 	} else {
277 		func = MV88E6352_G2_SCRATCH_GPIO_PCTL_GPIO;
278 
279 		err = mv88e6352_set_gpio_func(chip, pin, func, true);
280 
281 		cancel_delayed_work_sync(&chip->tai_event_work);
282 	}
283 
284 out:
285 	mutex_unlock(&chip->reg_lock);
286 
287 	return err;
288 }
289 
290 static int mv88e6352_ptp_enable(struct ptp_clock_info *ptp,
291 				struct ptp_clock_request *rq, int on)
292 {
293 	struct mv88e6xxx_chip *chip = ptp_to_chip(ptp);
294 
295 	switch (rq->type) {
296 	case PTP_CLK_REQ_EXTTS:
297 		return mv88e6352_ptp_enable_extts(chip, rq, on);
298 	default:
299 		return -EOPNOTSUPP;
300 	}
301 }
302 
303 static int mv88e6352_ptp_verify(struct ptp_clock_info *ptp, unsigned int pin,
304 				enum ptp_pin_function func, unsigned int chan)
305 {
306 	switch (func) {
307 	case PTP_PF_NONE:
308 	case PTP_PF_EXTTS:
309 		break;
310 	case PTP_PF_PEROUT:
311 	case PTP_PF_PHYSYNC:
312 		return -EOPNOTSUPP;
313 	}
314 	return 0;
315 }
316 
317 const struct mv88e6xxx_ptp_ops mv88e6352_ptp_ops = {
318 	.clock_read = mv88e6352_ptp_clock_read,
319 	.ptp_enable = mv88e6352_ptp_enable,
320 	.ptp_verify = mv88e6352_ptp_verify,
321 	.event_work = mv88e6352_tai_event_work,
322 	.port_enable = mv88e6352_hwtstamp_port_enable,
323 	.port_disable = mv88e6352_hwtstamp_port_disable,
324 	.n_ext_ts = 1,
325 	.arr0_sts_reg = MV88E6XXX_PORT_PTP_ARR0_STS,
326 	.arr1_sts_reg = MV88E6XXX_PORT_PTP_ARR1_STS,
327 	.dep_sts_reg = MV88E6XXX_PORT_PTP_DEP_STS,
328 	.rx_filters = (1 << HWTSTAMP_FILTER_NONE) |
329 		(1 << HWTSTAMP_FILTER_PTP_V2_L4_EVENT) |
330 		(1 << HWTSTAMP_FILTER_PTP_V2_L4_SYNC) |
331 		(1 << HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ) |
332 		(1 << HWTSTAMP_FILTER_PTP_V2_L2_EVENT) |
333 		(1 << HWTSTAMP_FILTER_PTP_V2_L2_SYNC) |
334 		(1 << HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ) |
335 		(1 << HWTSTAMP_FILTER_PTP_V2_EVENT) |
336 		(1 << HWTSTAMP_FILTER_PTP_V2_SYNC) |
337 		(1 << HWTSTAMP_FILTER_PTP_V2_DELAY_REQ),
338 };
339 
340 const struct mv88e6xxx_ptp_ops mv88e6165_ptp_ops = {
341 	.clock_read = mv88e6165_ptp_clock_read,
342 	.global_enable = mv88e6165_global_enable,
343 	.global_disable = mv88e6165_global_disable,
344 	.arr0_sts_reg = MV88E6165_PORT_PTP_ARR0_STS,
345 	.arr1_sts_reg = MV88E6165_PORT_PTP_ARR1_STS,
346 	.dep_sts_reg = MV88E6165_PORT_PTP_DEP_STS,
347 	.rx_filters = (1 << HWTSTAMP_FILTER_NONE) |
348 		(1 << HWTSTAMP_FILTER_PTP_V2_L2_EVENT) |
349 		(1 << HWTSTAMP_FILTER_PTP_V2_L2_SYNC) |
350 		(1 << HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ) |
351 		(1 << HWTSTAMP_FILTER_PTP_V2_EVENT) |
352 		(1 << HWTSTAMP_FILTER_PTP_V2_SYNC) |
353 		(1 << HWTSTAMP_FILTER_PTP_V2_DELAY_REQ),
354 };
355 
356 static u64 mv88e6xxx_ptp_clock_read(const struct cyclecounter *cc)
357 {
358 	struct mv88e6xxx_chip *chip = cc_to_chip(cc);
359 
360 	if (chip->info->ops->ptp_ops->clock_read)
361 		return chip->info->ops->ptp_ops->clock_read(cc);
362 
363 	return 0;
364 }
365 
366 /* With a 125MHz input clock, the 32-bit timestamp counter overflows in ~34.3
367  * seconds; this task forces periodic reads so that we don't miss any.
368  */
369 #define MV88E6XXX_TAI_OVERFLOW_PERIOD (HZ * 16)
370 static void mv88e6xxx_ptp_overflow_check(struct work_struct *work)
371 {
372 	struct delayed_work *dw = to_delayed_work(work);
373 	struct mv88e6xxx_chip *chip = dw_overflow_to_chip(dw);
374 	struct timespec64 ts;
375 
376 	mv88e6xxx_ptp_gettime(&chip->ptp_clock_info, &ts);
377 
378 	schedule_delayed_work(&chip->overflow_work,
379 			      MV88E6XXX_TAI_OVERFLOW_PERIOD);
380 }
381 
382 int mv88e6xxx_ptp_setup(struct mv88e6xxx_chip *chip)
383 {
384 	const struct mv88e6xxx_ptp_ops *ptp_ops = chip->info->ops->ptp_ops;
385 	int i;
386 
387 	/* Set up the cycle counter */
388 	memset(&chip->tstamp_cc, 0, sizeof(chip->tstamp_cc));
389 	chip->tstamp_cc.read	= mv88e6xxx_ptp_clock_read;
390 	chip->tstamp_cc.mask	= CYCLECOUNTER_MASK(32);
391 	chip->tstamp_cc.mult	= CC_MULT;
392 	chip->tstamp_cc.shift	= CC_SHIFT;
393 
394 	timecounter_init(&chip->tstamp_tc, &chip->tstamp_cc,
395 			 ktime_to_ns(ktime_get_real()));
396 
397 	INIT_DELAYED_WORK(&chip->overflow_work, mv88e6xxx_ptp_overflow_check);
398 	if (ptp_ops->event_work)
399 		INIT_DELAYED_WORK(&chip->tai_event_work, ptp_ops->event_work);
400 
401 	chip->ptp_clock_info.owner = THIS_MODULE;
402 	snprintf(chip->ptp_clock_info.name, sizeof(chip->ptp_clock_info.name),
403 		 dev_name(chip->dev));
404 	chip->ptp_clock_info.max_adj	= 1000000;
405 
406 	chip->ptp_clock_info.n_ext_ts	= ptp_ops->n_ext_ts;
407 	chip->ptp_clock_info.n_per_out	= 0;
408 	chip->ptp_clock_info.n_pins	= mv88e6xxx_num_gpio(chip);
409 	chip->ptp_clock_info.pps	= 0;
410 
411 	for (i = 0; i < chip->ptp_clock_info.n_pins; ++i) {
412 		struct ptp_pin_desc *ppd = &chip->pin_config[i];
413 
414 		snprintf(ppd->name, sizeof(ppd->name), "mv88e6xxx_gpio%d", i);
415 		ppd->index = i;
416 		ppd->func = PTP_PF_NONE;
417 	}
418 	chip->ptp_clock_info.pin_config = chip->pin_config;
419 
420 	chip->ptp_clock_info.adjfine	= mv88e6xxx_ptp_adjfine;
421 	chip->ptp_clock_info.adjtime	= mv88e6xxx_ptp_adjtime;
422 	chip->ptp_clock_info.gettime64	= mv88e6xxx_ptp_gettime;
423 	chip->ptp_clock_info.settime64	= mv88e6xxx_ptp_settime;
424 	chip->ptp_clock_info.enable	= ptp_ops->ptp_enable;
425 	chip->ptp_clock_info.verify	= ptp_ops->ptp_verify;
426 	chip->ptp_clock_info.do_aux_work = mv88e6xxx_hwtstamp_work;
427 
428 	chip->ptp_clock = ptp_clock_register(&chip->ptp_clock_info, chip->dev);
429 	if (IS_ERR(chip->ptp_clock))
430 		return PTR_ERR(chip->ptp_clock);
431 
432 	schedule_delayed_work(&chip->overflow_work,
433 			      MV88E6XXX_TAI_OVERFLOW_PERIOD);
434 
435 	return 0;
436 }
437 
438 void mv88e6xxx_ptp_free(struct mv88e6xxx_chip *chip)
439 {
440 	if (chip->ptp_clock) {
441 		cancel_delayed_work_sync(&chip->overflow_work);
442 		if (chip->info->ops->ptp_ops->event_work)
443 			cancel_delayed_work_sync(&chip->tai_event_work);
444 
445 		ptp_clock_unregister(chip->ptp_clock);
446 		chip->ptp_clock = NULL;
447 	}
448 }
449