cpts.c 9.6 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28
/*
 * TI Common Platform Time Sync
 *
 * Copyright (C) 2012 Richard Cochran <richardcochran@gmail.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#include <linux/err.h>
#include <linux/if.h>
#include <linux/hrtimer.h>
#include <linux/module.h>
#include <linux/net_tstamp.h>
#include <linux/ptp_classify.h>
#include <linux/time.h>
#include <linux/uaccess.h>
#include <linux/workqueue.h>
29 30
#include <linux/if_ether.h>
#include <linux/if_vlan.h>
31 32 33 34 35

#include "cpts.h"

#ifdef CONFIG_TI_CPTS

36 37
#define cpts_read32(c, r)	readl_relaxed(&c->reg->r)
#define cpts_write32(c, v, r)	writel_relaxed(v, &c->reg->r)
38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94

static int event_expired(struct cpts_event *event)
{
	return time_after(jiffies, event->tmo);
}

static int event_type(struct cpts_event *event)
{
	return (event->high >> EVENT_TYPE_SHIFT) & EVENT_TYPE_MASK;
}

static int cpts_fifo_pop(struct cpts *cpts, u32 *high, u32 *low)
{
	u32 r = cpts_read32(cpts, intstat_raw);

	if (r & TS_PEND_RAW) {
		*high = cpts_read32(cpts, event_high);
		*low  = cpts_read32(cpts, event_low);
		cpts_write32(cpts, EVENT_POP, event_pop);
		return 0;
	}
	return -1;
}

/*
 * Returns zero if matching event type was found.
 */
static int cpts_fifo_read(struct cpts *cpts, int match)
{
	int i, type = -1;
	u32 hi, lo;
	struct cpts_event *event;

	for (i = 0; i < CPTS_FIFO_DEPTH; i++) {
		if (cpts_fifo_pop(cpts, &hi, &lo))
			break;
		if (list_empty(&cpts->pool)) {
			pr_err("cpts: event pool is empty\n");
			return -1;
		}
		event = list_first_entry(&cpts->pool, struct cpts_event, list);
		event->tmo = jiffies + 2;
		event->high = hi;
		event->low = lo;
		type = event_type(event);
		switch (type) {
		case CPTS_EV_PUSH:
		case CPTS_EV_RX:
		case CPTS_EV_TX:
			list_del_init(&event->list);
			list_add_tail(&event->list, &cpts->events);
			break;
		case CPTS_EV_ROLL:
		case CPTS_EV_HALF:
		case CPTS_EV_HW:
			break;
		default:
M
Masanari Iida 已提交
95
			pr_err("cpts: unknown event type\n");
96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163
			break;
		}
		if (type == match)
			break;
	}
	return type == match ? 0 : -1;
}

static cycle_t cpts_systim_read(const struct cyclecounter *cc)
{
	u64 val = 0;
	struct cpts_event *event;
	struct list_head *this, *next;
	struct cpts *cpts = container_of(cc, struct cpts, cc);

	cpts_write32(cpts, TS_PUSH, ts_push);
	if (cpts_fifo_read(cpts, CPTS_EV_PUSH))
		pr_err("cpts: unable to obtain a time stamp\n");

	list_for_each_safe(this, next, &cpts->events) {
		event = list_entry(this, struct cpts_event, list);
		if (event_type(event) == CPTS_EV_PUSH) {
			list_del_init(&event->list);
			list_add(&event->list, &cpts->pool);
			val = event->low;
			break;
		}
	}

	return val;
}

/* PTP clock operations */

static int cpts_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
{
	u64 adj;
	u32 diff, mult;
	int neg_adj = 0;
	unsigned long flags;
	struct cpts *cpts = container_of(ptp, struct cpts, info);

	if (ppb < 0) {
		neg_adj = 1;
		ppb = -ppb;
	}
	mult = cpts->cc_mult;
	adj = mult;
	adj *= ppb;
	diff = div_u64(adj, 1000000000ULL);

	spin_lock_irqsave(&cpts->lock, flags);

	timecounter_read(&cpts->tc);

	cpts->cc.mult = neg_adj ? mult - diff : mult + diff;

	spin_unlock_irqrestore(&cpts->lock, flags);

	return 0;
}

static int cpts_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
{
	unsigned long flags;
	struct cpts *cpts = container_of(ptp, struct cpts, info);

	spin_lock_irqsave(&cpts->lock, flags);
164
	timecounter_adjtime(&cpts->tc, delta);
165 166 167 168 169
	spin_unlock_irqrestore(&cpts->lock, flags);

	return 0;
}

170
static int cpts_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
171 172 173 174 175 176 177 178 179
{
	u64 ns;
	unsigned long flags;
	struct cpts *cpts = container_of(ptp, struct cpts, info);

	spin_lock_irqsave(&cpts->lock, flags);
	ns = timecounter_read(&cpts->tc);
	spin_unlock_irqrestore(&cpts->lock, flags);

180
	*ts = ns_to_timespec64(ns);
181 182 183 184 185

	return 0;
}

static int cpts_ptp_settime(struct ptp_clock_info *ptp,
186
			    const struct timespec64 *ts)
187 188 189 190 191
{
	u64 ns;
	unsigned long flags;
	struct cpts *cpts = container_of(ptp, struct cpts, info);

192
	ns = timespec64_to_ns(ts);
193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211

	spin_lock_irqsave(&cpts->lock, flags);
	timecounter_init(&cpts->tc, &cpts->cc, ns);
	spin_unlock_irqrestore(&cpts->lock, flags);

	return 0;
}

static int cpts_ptp_enable(struct ptp_clock_info *ptp,
			   struct ptp_clock_request *rq, int on)
{
	return -EOPNOTSUPP;
}

static struct ptp_clock_info cpts_info = {
	.owner		= THIS_MODULE,
	.name		= "CTPS timer",
	.max_adj	= 1000000,
	.n_ext_ts	= 0,
212
	.n_pins		= 0,
213 214 215
	.pps		= 0,
	.adjfreq	= cpts_ptp_adjfreq,
	.adjtime	= cpts_ptp_adjtime,
216 217
	.gettime64	= cpts_ptp_gettime,
	.settime64	= cpts_ptp_settime,
218 219 220 221 222
	.enable		= cpts_ptp_enable,
};

static void cpts_overflow_check(struct work_struct *work)
{
223
	struct timespec64 ts;
224 225 226 227 228
	struct cpts *cpts = container_of(work, struct cpts, overflow_work.work);

	cpts_write32(cpts, CPTS_EN, control);
	cpts_write32(cpts, TS_PEND_EN, int_enable);
	cpts_ptp_gettime(&cpts->info, &ts);
229
	pr_debug("cpts overflow check at %lld.%09lu\n", ts.tv_sec, ts.tv_nsec);
230 231 232
	schedule_delayed_work(&cpts->overflow_work, CPTS_OVERFLOW_PERIOD);
}

233
static void cpts_clk_init(struct device *dev, struct cpts *cpts)
234
{
235
	cpts->refclk = devm_clk_get(dev, "cpts");
236
	if (IS_ERR(cpts->refclk)) {
237
		dev_err(dev, "Failed to get cpts refclk\n");
238 239 240
		cpts->refclk = NULL;
		return;
	}
R
Richard Cochran 已提交
241
	clk_prepare_enable(cpts->refclk);
242 243 244 245 246 247 248 249 250 251 252
}

static void cpts_clk_release(struct cpts *cpts)
{
	clk_disable(cpts->refclk);
}

static int cpts_match(struct sk_buff *skb, unsigned int ptp_class,
		      u16 ts_seqid, u8 ts_msgtype)
{
	u16 *seqid;
253
	unsigned int offset = 0;
254 255
	u8 *msgtype, *data = skb->data;

256 257 258 259 260
	if (ptp_class & PTP_CLASS_VLAN)
		offset += VLAN_HLEN;

	switch (ptp_class & PTP_CLASS_PMASK) {
	case PTP_CLASS_IPV4:
261
		offset += ETH_HLEN + IPV4_HLEN(data + offset) + UDP_HLEN;
262
		break;
263 264
	case PTP_CLASS_IPV6:
		offset += ETH_HLEN + IP6_HLEN + UDP_HLEN;
265
		break;
266 267
	case PTP_CLASS_L2:
		offset += ETH_HLEN;
268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290
		break;
	default:
		return 0;
	}

	if (skb->len + ETH_HLEN < offset + OFF_PTP_SEQUENCE_ID + sizeof(*seqid))
		return 0;

	if (unlikely(ptp_class & PTP_CLASS_V1))
		msgtype = data + offset + OFF_PTP_CONTROL;
	else
		msgtype = data + offset;

	seqid = (u16 *)(data + offset + OFF_PTP_SEQUENCE_ID);

	return (ts_msgtype == (*msgtype & 0xf) && ts_seqid == ntohs(*seqid));
}

static u64 cpts_find_ts(struct cpts *cpts, struct sk_buff *skb, int ev_type)
{
	u64 ns = 0;
	struct cpts_event *event;
	struct list_head *this, *next;
291
	unsigned int class = ptp_classify_raw(skb);
292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381
	unsigned long flags;
	u16 seqid;
	u8 mtype;

	if (class == PTP_CLASS_NONE)
		return 0;

	spin_lock_irqsave(&cpts->lock, flags);
	cpts_fifo_read(cpts, CPTS_EV_PUSH);
	list_for_each_safe(this, next, &cpts->events) {
		event = list_entry(this, struct cpts_event, list);
		if (event_expired(event)) {
			list_del_init(&event->list);
			list_add(&event->list, &cpts->pool);
			continue;
		}
		mtype = (event->high >> MESSAGE_TYPE_SHIFT) & MESSAGE_TYPE_MASK;
		seqid = (event->high >> SEQUENCE_ID_SHIFT) & SEQUENCE_ID_MASK;
		if (ev_type == event_type(event) &&
		    cpts_match(skb, class, seqid, mtype)) {
			ns = timecounter_cyc2time(&cpts->tc, event->low);
			list_del_init(&event->list);
			list_add(&event->list, &cpts->pool);
			break;
		}
	}
	spin_unlock_irqrestore(&cpts->lock, flags);

	return ns;
}

void cpts_rx_timestamp(struct cpts *cpts, struct sk_buff *skb)
{
	u64 ns;
	struct skb_shared_hwtstamps *ssh;

	if (!cpts->rx_enable)
		return;
	ns = cpts_find_ts(cpts, skb, CPTS_EV_RX);
	if (!ns)
		return;
	ssh = skb_hwtstamps(skb);
	memset(ssh, 0, sizeof(*ssh));
	ssh->hwtstamp = ns_to_ktime(ns);
}

void cpts_tx_timestamp(struct cpts *cpts, struct sk_buff *skb)
{
	u64 ns;
	struct skb_shared_hwtstamps ssh;

	if (!(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
		return;
	ns = cpts_find_ts(cpts, skb, CPTS_EV_TX);
	if (!ns)
		return;
	memset(&ssh, 0, sizeof(ssh));
	ssh.hwtstamp = ns_to_ktime(ns);
	skb_tstamp_tx(skb, &ssh);
}

#endif /*CONFIG_TI_CPTS*/

int cpts_register(struct device *dev, struct cpts *cpts,
		  u32 mult, u32 shift)
{
#ifdef CONFIG_TI_CPTS
	int err, i;
	unsigned long flags;

	cpts->info = cpts_info;
	cpts->clock = ptp_clock_register(&cpts->info, dev);
	if (IS_ERR(cpts->clock)) {
		err = PTR_ERR(cpts->clock);
		cpts->clock = NULL;
		return err;
	}
	spin_lock_init(&cpts->lock);

	cpts->cc.read = cpts_systim_read;
	cpts->cc.mask = CLOCKSOURCE_MASK(32);
	cpts->cc_mult = mult;
	cpts->cc.mult = mult;
	cpts->cc.shift = shift;

	INIT_LIST_HEAD(&cpts->events);
	INIT_LIST_HEAD(&cpts->pool);
	for (i = 0; i < CPTS_MAX_EVENTS; i++)
		list_add(&cpts->pool_data[i].list, &cpts->pool);

382
	cpts_clk_init(dev, cpts);
383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408
	cpts_write32(cpts, CPTS_EN, control);
	cpts_write32(cpts, TS_PEND_EN, int_enable);

	spin_lock_irqsave(&cpts->lock, flags);
	timecounter_init(&cpts->tc, &cpts->cc, ktime_to_ns(ktime_get_real()));
	spin_unlock_irqrestore(&cpts->lock, flags);

	INIT_DELAYED_WORK(&cpts->overflow_work, cpts_overflow_check);
	schedule_delayed_work(&cpts->overflow_work, CPTS_OVERFLOW_PERIOD);

	cpts->phc_index = ptp_clock_index(cpts->clock);
#endif
	return 0;
}

void cpts_unregister(struct cpts *cpts)
{
#ifdef CONFIG_TI_CPTS
	if (cpts->clock) {
		ptp_clock_unregister(cpts->clock);
		cancel_delayed_work_sync(&cpts->overflow_work);
	}
	if (cpts->refclk)
		cpts_clk_release(cpts);
#endif
}