/* * TI Common Platform Time Sync * * Copyright (C) 2012 Richard Cochran * * 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 #include #include #include #include #include #include #include #include #include #include #include "cpts.h" #define CPTS_SKB_TX_WORK_TIMEOUT 1 /* jiffies */ struct cpts_skb_cb_data { unsigned long tmo; }; #define cpts_read32(c, r) readl_relaxed(&c->reg->r) #define cpts_write32(c, v, r) writel_relaxed(v, &c->reg->r) static int cpts_match(struct sk_buff *skb, unsigned int ptp_class, u16 ts_seqid, u8 ts_msgtype); 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; } static int cpts_purge_events(struct cpts *cpts) { struct list_head *this, *next; struct cpts_event *event; int removed = 0; 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); ++removed; } } if (removed) pr_debug("cpts: event pool cleaned up %d\n", removed); return removed ? 0 : -1; } static bool cpts_match_tx_ts(struct cpts *cpts, struct cpts_event *event) { struct sk_buff *skb, *tmp; u16 seqid; u8 mtype; bool found = false; mtype = (event->high >> MESSAGE_TYPE_SHIFT) & MESSAGE_TYPE_MASK; seqid = (event->high >> SEQUENCE_ID_SHIFT) & SEQUENCE_ID_MASK; /* no need to grab txq.lock as access is always done under cpts->lock */ skb_queue_walk_safe(&cpts->txq, skb, tmp) { struct skb_shared_hwtstamps ssh; unsigned int class = ptp_classify_raw(skb); struct cpts_skb_cb_data *skb_cb = (struct cpts_skb_cb_data *)skb->cb; if (cpts_match(skb, class, seqid, mtype)) { u64 ns = timecounter_cyc2time(&cpts->tc, event->low); memset(&ssh, 0, sizeof(ssh)); ssh.hwtstamp = ns_to_ktime(ns); skb_tstamp_tx(skb, &ssh); found = true; __skb_unlink(skb, &cpts->txq); dev_consume_skb_any(skb); dev_dbg(cpts->dev, "match tx timestamp mtype %u seqid %04x\n", mtype, seqid); break; } if (time_after(jiffies, skb_cb->tmo)) { /* timeout any expired skbs over 1s */ dev_dbg(cpts->dev, "expiring tx timestamp from txq\n"); __skb_unlink(skb, &cpts->txq); dev_consume_skb_any(skb); } } return found; } /* * 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) && cpts_purge_events(cpts)) { pr_err("cpts: event pool 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_TX: if (cpts_match_tx_ts(cpts, event)) { /* if the new event matches an existing skb, * then don't queue it */ break; } /* fall through */ case CPTS_EV_PUSH: case CPTS_EV_RX: 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: pr_err("cpts: unknown event type\n"); break; } if (type == match) break; } return type == match ? 0 : -1; } static u64 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); timecounter_adjtime(&cpts->tc, delta); spin_unlock_irqrestore(&cpts->lock, flags); return 0; } static int cpts_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts) { 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); *ts = ns_to_timespec64(ns); return 0; } static int cpts_ptp_settime(struct ptp_clock_info *ptp, const struct timespec64 *ts) { u64 ns; unsigned long flags; struct cpts *cpts = container_of(ptp, struct cpts, info); ns = timespec64_to_ns(ts); 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 long cpts_overflow_check(struct ptp_clock_info *ptp) { struct cpts *cpts = container_of(ptp, struct cpts, info); unsigned long delay = cpts->ov_check_period; struct timespec64 ts; unsigned long flags; spin_lock_irqsave(&cpts->lock, flags); ts = ns_to_timespec64(timecounter_read(&cpts->tc)); if (!skb_queue_empty(&cpts->txq)) delay = CPTS_SKB_TX_WORK_TIMEOUT; spin_unlock_irqrestore(&cpts->lock, flags); pr_debug("cpts overflow check at %lld.%09ld\n", (long long)ts.tv_sec, ts.tv_nsec); return (long)delay; } static const struct ptp_clock_info cpts_info = { .owner = THIS_MODULE, .name = "CTPS timer", .max_adj = 1000000, .n_ext_ts = 0, .n_pins = 0, .pps = 0, .adjfreq = cpts_ptp_adjfreq, .adjtime = cpts_ptp_adjtime, .gettime64 = cpts_ptp_gettime, .settime64 = cpts_ptp_settime, .enable = cpts_ptp_enable, .do_aux_work = cpts_overflow_check, }; static int cpts_match(struct sk_buff *skb, unsigned int ptp_class, u16 ts_seqid, u8 ts_msgtype) { u16 *seqid; unsigned int offset = 0; u8 *msgtype, *data = skb->data; if (ptp_class & PTP_CLASS_VLAN) offset += VLAN_HLEN; switch (ptp_class & PTP_CLASS_PMASK) { case PTP_CLASS_IPV4: offset += ETH_HLEN + IPV4_HLEN(data + offset) + UDP_HLEN; break; case PTP_CLASS_IPV6: offset += ETH_HLEN + IP6_HLEN + UDP_HLEN; break; case PTP_CLASS_L2: offset += ETH_HLEN; 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; unsigned int class = ptp_classify_raw(skb); unsigned long flags; u16 seqid; u8 mtype; if (class == PTP_CLASS_NONE) return 0; spin_lock_irqsave(&cpts->lock, flags); cpts_fifo_read(cpts, -1); 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; } } if (ev_type == CPTS_EV_TX && !ns) { struct cpts_skb_cb_data *skb_cb = (struct cpts_skb_cb_data *)skb->cb; /* Not found, add frame to queue for processing later. * The periodic FIFO check will handle this. */ skb_get(skb); /* get the timestamp for timeouts */ skb_cb->tmo = jiffies + msecs_to_jiffies(100); __skb_queue_tail(&cpts->txq, skb); ptp_schedule_worker(cpts->clock, 0); } 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); } EXPORT_SYMBOL_GPL(cpts_rx_timestamp); 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); } EXPORT_SYMBOL_GPL(cpts_tx_timestamp); int cpts_register(struct cpts *cpts) { int err, i; skb_queue_head_init(&cpts->txq); 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); err = clk_enable(cpts->refclk); if (err) return err; cpts_write32(cpts, CPTS_EN, control); cpts_write32(cpts, TS_PEND_EN, int_enable); timecounter_init(&cpts->tc, &cpts->cc, ktime_to_ns(ktime_get_real())); cpts->clock = ptp_clock_register(&cpts->info, cpts->dev); if (IS_ERR(cpts->clock)) { err = PTR_ERR(cpts->clock); cpts->clock = NULL; goto err_ptp; } cpts->phc_index = ptp_clock_index(cpts->clock); ptp_schedule_worker(cpts->clock, cpts->ov_check_period); return 0; err_ptp: clk_disable(cpts->refclk); return err; } EXPORT_SYMBOL_GPL(cpts_register); void cpts_unregister(struct cpts *cpts) { if (WARN_ON(!cpts->clock)) return; ptp_clock_unregister(cpts->clock); cpts->clock = NULL; cpts->phc_index = -1; cpts_write32(cpts, 0, int_enable); cpts_write32(cpts, 0, control); /* Drop all packet */ skb_queue_purge(&cpts->txq); clk_disable(cpts->refclk); } EXPORT_SYMBOL_GPL(cpts_unregister); static void cpts_calc_mult_shift(struct cpts *cpts) { u64 frac, maxsec, ns; u32 freq; freq = clk_get_rate(cpts->refclk); /* Calc the maximum number of seconds which we can run before * wrapping around. */ maxsec = cpts->cc.mask; do_div(maxsec, freq); /* limit conversation rate to 10 sec as higher values will produce * too small mult factors and so reduce the conversion accuracy */ if (maxsec > 10) maxsec = 10; /* Calc overflow check period (maxsec / 2) */ cpts->ov_check_period = (HZ * maxsec) / 2; dev_info(cpts->dev, "cpts: overflow check period %lu (jiffies)\n", cpts->ov_check_period); if (cpts->cc.mult || cpts->cc.shift) return; clocks_calc_mult_shift(&cpts->cc.mult, &cpts->cc.shift, freq, NSEC_PER_SEC, maxsec); frac = 0; ns = cyclecounter_cyc2ns(&cpts->cc, freq, cpts->cc.mask, &frac); dev_info(cpts->dev, "CPTS: ref_clk_freq:%u calc_mult:%u calc_shift:%u error:%lld nsec/sec\n", freq, cpts->cc.mult, cpts->cc.shift, (ns - NSEC_PER_SEC)); } static int cpts_of_parse(struct cpts *cpts, struct device_node *node) { int ret = -EINVAL; u32 prop; if (!of_property_read_u32(node, "cpts_clock_mult", &prop)) cpts->cc.mult = prop; if (!of_property_read_u32(node, "cpts_clock_shift", &prop)) cpts->cc.shift = prop; if ((cpts->cc.mult && !cpts->cc.shift) || (!cpts->cc.mult && cpts->cc.shift)) goto of_error; return 0; of_error: dev_err(cpts->dev, "CPTS: Missing property in the DT.\n"); return ret; } struct cpts *cpts_create(struct device *dev, void __iomem *regs, struct device_node *node) { struct cpts *cpts; int ret; cpts = devm_kzalloc(dev, sizeof(*cpts), GFP_KERNEL); if (!cpts) return ERR_PTR(-ENOMEM); cpts->dev = dev; cpts->reg = (struct cpsw_cpts __iomem *)regs; spin_lock_init(&cpts->lock); ret = cpts_of_parse(cpts, node); if (ret) return ERR_PTR(ret); cpts->refclk = devm_clk_get(dev, "cpts"); if (IS_ERR(cpts->refclk)) { dev_err(dev, "Failed to get cpts refclk\n"); return ERR_CAST(cpts->refclk); } ret = clk_prepare(cpts->refclk); if (ret) return ERR_PTR(ret); cpts->cc.read = cpts_systim_read; cpts->cc.mask = CLOCKSOURCE_MASK(32); cpts->info = cpts_info; cpts->phc_index = -1; cpts_calc_mult_shift(cpts); /* save cc.mult original value as it can be modified * by cpts_ptp_adjfreq(). */ cpts->cc_mult = cpts->cc.mult; return cpts; } EXPORT_SYMBOL_GPL(cpts_create); void cpts_release(struct cpts *cpts) { if (!cpts) return; if (WARN_ON(!cpts->refclk)) return; clk_unprepare(cpts->refclk); } EXPORT_SYMBOL_GPL(cpts_release); MODULE_LICENSE("GPL v2"); MODULE_DESCRIPTION("TI CPTS driver"); MODULE_AUTHOR("Richard Cochran ");