2 * TI Common Platform Time Sync
4 * Copyright (C) 2012 Richard Cochran <richardcochran@gmail.com>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 #include <linux/err.h>
22 #include <linux/hrtimer.h>
23 #include <linux/module.h>
24 #include <linux/net_tstamp.h>
25 #include <linux/ptp_classify.h>
26 #include <linux/time.h>
27 #include <linux/uaccess.h>
28 #include <linux/workqueue.h>
29 #include <linux/if_ether.h>
30 #include <linux/if_vlan.h>
34 #define cpts_read32(c, r) readl_relaxed(&c->reg->r)
35 #define cpts_write32(c, v, r) writel_relaxed(v, &c->reg->r)
37 static int event_expired(struct cpts_event *event)
39 return time_after(jiffies, event->tmo);
42 static int event_type(struct cpts_event *event)
44 return (event->high >> EVENT_TYPE_SHIFT) & EVENT_TYPE_MASK;
47 static int cpts_fifo_pop(struct cpts *cpts, u32 *high, u32 *low)
49 u32 r = cpts_read32(cpts, intstat_raw);
51 if (r & TS_PEND_RAW) {
52 *high = cpts_read32(cpts, event_high);
53 *low = cpts_read32(cpts, event_low);
54 cpts_write32(cpts, EVENT_POP, event_pop);
60 static int cpts_purge_events(struct cpts *cpts)
62 struct list_head *this, *next;
63 struct cpts_event *event;
66 list_for_each_safe(this, next, &cpts->events) {
67 event = list_entry(this, struct cpts_event, list);
68 if (event_expired(event)) {
69 list_del_init(&event->list);
70 list_add(&event->list, &cpts->pool);
76 pr_debug("cpts: event pool cleaned up %d\n", removed);
77 return removed ? 0 : -1;
81 * Returns zero if matching event type was found.
83 static int cpts_fifo_read(struct cpts *cpts, int match)
87 struct cpts_event *event;
89 for (i = 0; i < CPTS_FIFO_DEPTH; i++) {
90 if (cpts_fifo_pop(cpts, &hi, &lo))
93 if (list_empty(&cpts->pool) && cpts_purge_events(cpts)) {
94 pr_err("cpts: event pool empty\n");
98 event = list_first_entry(&cpts->pool, struct cpts_event, list);
99 event->tmo = jiffies + 2;
102 type = event_type(event);
107 list_del_init(&event->list);
108 list_add_tail(&event->list, &cpts->events);
115 pr_err("cpts: unknown event type\n");
121 return type == match ? 0 : -1;
124 static u64 cpts_systim_read(const struct cyclecounter *cc)
127 struct cpts_event *event;
128 struct list_head *this, *next;
129 struct cpts *cpts = container_of(cc, struct cpts, cc);
131 cpts_write32(cpts, TS_PUSH, ts_push);
132 if (cpts_fifo_read(cpts, CPTS_EV_PUSH))
133 pr_err("cpts: unable to obtain a time stamp\n");
135 list_for_each_safe(this, next, &cpts->events) {
136 event = list_entry(this, struct cpts_event, list);
137 if (event_type(event) == CPTS_EV_PUSH) {
138 list_del_init(&event->list);
139 list_add(&event->list, &cpts->pool);
148 /* PTP clock operations */
150 static int cpts_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
156 struct cpts *cpts = container_of(ptp, struct cpts, info);
162 mult = cpts->cc_mult;
165 diff = div_u64(adj, 1000000000ULL);
167 spin_lock_irqsave(&cpts->lock, flags);
169 timecounter_read(&cpts->tc);
171 cpts->cc.mult = neg_adj ? mult - diff : mult + diff;
173 spin_unlock_irqrestore(&cpts->lock, flags);
178 static int cpts_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
181 struct cpts *cpts = container_of(ptp, struct cpts, info);
183 spin_lock_irqsave(&cpts->lock, flags);
184 timecounter_adjtime(&cpts->tc, delta);
185 spin_unlock_irqrestore(&cpts->lock, flags);
190 static int cpts_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts)
194 struct cpts *cpts = container_of(ptp, struct cpts, info);
196 spin_lock_irqsave(&cpts->lock, flags);
197 ns = timecounter_read(&cpts->tc);
198 spin_unlock_irqrestore(&cpts->lock, flags);
200 *ts = ns_to_timespec64(ns);
205 static int cpts_ptp_settime(struct ptp_clock_info *ptp,
206 const struct timespec64 *ts)
210 struct cpts *cpts = container_of(ptp, struct cpts, info);
212 ns = timespec64_to_ns(ts);
214 spin_lock_irqsave(&cpts->lock, flags);
215 timecounter_init(&cpts->tc, &cpts->cc, ns);
216 spin_unlock_irqrestore(&cpts->lock, flags);
221 static int cpts_ptp_enable(struct ptp_clock_info *ptp,
222 struct ptp_clock_request *rq, int on)
227 static struct ptp_clock_info cpts_info = {
228 .owner = THIS_MODULE,
229 .name = "CTPS timer",
234 .adjfreq = cpts_ptp_adjfreq,
235 .adjtime = cpts_ptp_adjtime,
236 .gettime64 = cpts_ptp_gettime,
237 .settime64 = cpts_ptp_settime,
238 .enable = cpts_ptp_enable,
241 static void cpts_overflow_check(struct work_struct *work)
243 struct timespec64 ts;
244 struct cpts *cpts = container_of(work, struct cpts, overflow_work.work);
246 cpts_ptp_gettime(&cpts->info, &ts);
247 pr_debug("cpts overflow check at %lld.%09lu\n", ts.tv_sec, ts.tv_nsec);
248 schedule_delayed_work(&cpts->overflow_work, cpts->ov_check_period);
251 static int cpts_match(struct sk_buff *skb, unsigned int ptp_class,
252 u16 ts_seqid, u8 ts_msgtype)
255 unsigned int offset = 0;
256 u8 *msgtype, *data = skb->data;
258 if (ptp_class & PTP_CLASS_VLAN)
261 switch (ptp_class & PTP_CLASS_PMASK) {
263 offset += ETH_HLEN + IPV4_HLEN(data + offset) + UDP_HLEN;
266 offset += ETH_HLEN + IP6_HLEN + UDP_HLEN;
275 if (skb->len + ETH_HLEN < offset + OFF_PTP_SEQUENCE_ID + sizeof(*seqid))
278 if (unlikely(ptp_class & PTP_CLASS_V1))
279 msgtype = data + offset + OFF_PTP_CONTROL;
281 msgtype = data + offset;
283 seqid = (u16 *)(data + offset + OFF_PTP_SEQUENCE_ID);
285 return (ts_msgtype == (*msgtype & 0xf) && ts_seqid == ntohs(*seqid));
288 static u64 cpts_find_ts(struct cpts *cpts, struct sk_buff *skb, int ev_type)
291 struct cpts_event *event;
292 struct list_head *this, *next;
293 unsigned int class = ptp_classify_raw(skb);
298 if (class == PTP_CLASS_NONE)
301 spin_lock_irqsave(&cpts->lock, flags);
302 cpts_fifo_read(cpts, CPTS_EV_PUSH);
303 list_for_each_safe(this, next, &cpts->events) {
304 event = list_entry(this, struct cpts_event, list);
305 if (event_expired(event)) {
306 list_del_init(&event->list);
307 list_add(&event->list, &cpts->pool);
310 mtype = (event->high >> MESSAGE_TYPE_SHIFT) & MESSAGE_TYPE_MASK;
311 seqid = (event->high >> SEQUENCE_ID_SHIFT) & SEQUENCE_ID_MASK;
312 if (ev_type == event_type(event) &&
313 cpts_match(skb, class, seqid, mtype)) {
314 ns = timecounter_cyc2time(&cpts->tc, event->low);
315 list_del_init(&event->list);
316 list_add(&event->list, &cpts->pool);
320 spin_unlock_irqrestore(&cpts->lock, flags);
325 void cpts_rx_timestamp(struct cpts *cpts, struct sk_buff *skb)
328 struct skb_shared_hwtstamps *ssh;
330 if (!cpts->rx_enable)
332 ns = cpts_find_ts(cpts, skb, CPTS_EV_RX);
335 ssh = skb_hwtstamps(skb);
336 memset(ssh, 0, sizeof(*ssh));
337 ssh->hwtstamp = ns_to_ktime(ns);
339 EXPORT_SYMBOL_GPL(cpts_rx_timestamp);
341 void cpts_tx_timestamp(struct cpts *cpts, struct sk_buff *skb)
344 struct skb_shared_hwtstamps ssh;
346 if (!(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
348 ns = cpts_find_ts(cpts, skb, CPTS_EV_TX);
351 memset(&ssh, 0, sizeof(ssh));
352 ssh.hwtstamp = ns_to_ktime(ns);
353 skb_tstamp_tx(skb, &ssh);
355 EXPORT_SYMBOL_GPL(cpts_tx_timestamp);
357 int cpts_register(struct cpts *cpts)
361 INIT_LIST_HEAD(&cpts->events);
362 INIT_LIST_HEAD(&cpts->pool);
363 for (i = 0; i < CPTS_MAX_EVENTS; i++)
364 list_add(&cpts->pool_data[i].list, &cpts->pool);
366 clk_enable(cpts->refclk);
368 cpts_write32(cpts, CPTS_EN, control);
369 cpts_write32(cpts, TS_PEND_EN, int_enable);
371 timecounter_init(&cpts->tc, &cpts->cc, ktime_to_ns(ktime_get_real()));
373 cpts->clock = ptp_clock_register(&cpts->info, cpts->dev);
374 if (IS_ERR(cpts->clock)) {
375 err = PTR_ERR(cpts->clock);
379 cpts->phc_index = ptp_clock_index(cpts->clock);
381 schedule_delayed_work(&cpts->overflow_work, cpts->ov_check_period);
385 clk_disable(cpts->refclk);
388 EXPORT_SYMBOL_GPL(cpts_register);
390 void cpts_unregister(struct cpts *cpts)
392 if (WARN_ON(!cpts->clock))
395 cancel_delayed_work_sync(&cpts->overflow_work);
397 ptp_clock_unregister(cpts->clock);
400 cpts_write32(cpts, 0, int_enable);
401 cpts_write32(cpts, 0, control);
403 clk_disable(cpts->refclk);
405 EXPORT_SYMBOL_GPL(cpts_unregister);
407 static void cpts_calc_mult_shift(struct cpts *cpts)
409 u64 frac, maxsec, ns;
412 freq = clk_get_rate(cpts->refclk);
414 /* Calc the maximum number of seconds which we can run before
417 maxsec = cpts->cc.mask;
418 do_div(maxsec, freq);
419 /* limit conversation rate to 10 sec as higher values will produce
420 * too small mult factors and so reduce the conversion accuracy
425 /* Calc overflow check period (maxsec / 2) */
426 cpts->ov_check_period = (HZ * maxsec) / 2;
427 dev_info(cpts->dev, "cpts: overflow check period %lu (jiffies)\n",
428 cpts->ov_check_period);
430 if (cpts->cc.mult || cpts->cc.shift)
433 clocks_calc_mult_shift(&cpts->cc.mult, &cpts->cc.shift,
434 freq, NSEC_PER_SEC, maxsec);
437 ns = cyclecounter_cyc2ns(&cpts->cc, freq, cpts->cc.mask, &frac);
440 "CPTS: ref_clk_freq:%u calc_mult:%u calc_shift:%u error:%lld nsec/sec\n",
441 freq, cpts->cc.mult, cpts->cc.shift, (ns - NSEC_PER_SEC));
444 static int cpts_of_parse(struct cpts *cpts, struct device_node *node)
449 if (!of_property_read_u32(node, "cpts_clock_mult", &prop))
450 cpts->cc.mult = prop;
452 if (!of_property_read_u32(node, "cpts_clock_shift", &prop))
453 cpts->cc.shift = prop;
455 if ((cpts->cc.mult && !cpts->cc.shift) ||
456 (!cpts->cc.mult && cpts->cc.shift))
462 dev_err(cpts->dev, "CPTS: Missing property in the DT.\n");
466 struct cpts *cpts_create(struct device *dev, void __iomem *regs,
467 struct device_node *node)
472 cpts = devm_kzalloc(dev, sizeof(*cpts), GFP_KERNEL);
474 return ERR_PTR(-ENOMEM);
477 cpts->reg = (struct cpsw_cpts __iomem *)regs;
478 spin_lock_init(&cpts->lock);
479 INIT_DELAYED_WORK(&cpts->overflow_work, cpts_overflow_check);
481 ret = cpts_of_parse(cpts, node);
485 cpts->refclk = devm_clk_get(dev, "cpts");
486 if (IS_ERR(cpts->refclk)) {
487 dev_err(dev, "Failed to get cpts refclk\n");
488 return ERR_PTR(PTR_ERR(cpts->refclk));
491 clk_prepare(cpts->refclk);
493 cpts->cc.read = cpts_systim_read;
494 cpts->cc.mask = CLOCKSOURCE_MASK(32);
495 cpts->info = cpts_info;
497 cpts_calc_mult_shift(cpts);
498 /* save cc.mult original value as it can be modified
499 * by cpts_ptp_adjfreq().
501 cpts->cc_mult = cpts->cc.mult;
505 EXPORT_SYMBOL_GPL(cpts_create);
507 void cpts_release(struct cpts *cpts)
512 if (WARN_ON(!cpts->refclk))
515 clk_unprepare(cpts->refclk);
517 EXPORT_SYMBOL_GPL(cpts_release);
519 MODULE_LICENSE("GPL v2");
520 MODULE_DESCRIPTION("TI CPTS driver");
521 MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");