text: // SPDX-License-Identifier: GPL-2.0+
  /*
   * TI Common Platform Time Sync
   *
   * Copyright (C) 2012 Richard Cochran <richardcochran@gmail.com>
   *
   */
  #include <linux/clk-provider.h>
  #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>
  #include <linux/if_ether.h>
  #include <linux/if_vlan.h>
  
  #include "cpts.h"
  
  #define CPTS_SKB_TX_WORK_TIMEOUT 1 /* jiffies */
  #define CPTS_SKB_RX_TX_TMO 100 /*ms */
  #define CPTS_EVENT_RX_TX_TIMEOUT (100) /* ms */
  
  struct cpts_skb_cb_data {
  	u32 skb_mtype_seqid;
  	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_event_port(struct cpts_event *event)
  {
  	return (event->high >> PORT_NUMBER_SHIFT) & PORT_NUMBER_MASK;
  }
  
  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)
  		dev_dbg(cpts->dev, "cpts: event pool cleaned up %d\n", removed);
  	return removed ? 0 : -1;
  }
  
  static void cpts_purge_txq(struct cpts *cpts)
  {
  	struct cpts_skb_cb_data *skb_cb;
  	struct sk_buff *skb, *tmp;
  	int removed = 0;
  
  	skb_queue_walk_safe(&cpts->txq, skb, tmp) {
  		skb_cb = (struct cpts_skb_cb_data *)skb->cb;
  		if (time_after(jiffies, skb_cb->tmo)) {
  			__skb_unlink(skb, &cpts->txq);
  			dev_consume_skb_any(skb);
  			++removed;
  		}
  	}
  
  	if (removed)
  		dev_dbg(cpts->dev, "txq cleaned up %d\n", removed);
  }
  
  /*
   * Returns zero if matching event type was found.
   */
  static int cpts_fifo_read(struct cpts *cpts, int match)
  {
  	struct ptp_clock_event pevent;
  	bool need_schedule = false;
  	struct cpts_event *event;
  	unsigned long flags;
  	int i, type = -1;
  	u32 hi, lo;
  
  	spin_lock_irqsave(&cpts->lock, flags);
  
  	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)) {
  			dev_warn(cpts->dev, "cpts: event pool empty\n");
  			break;
  		}
  
  		event = list_first_entry(&cpts->pool, struct cpts_event, list);
  		event->high = hi;
  		event->low = lo;
  		event->timestamp = timecounter_cyc2time(&cpts->tc, event->low);
  		type = event_type(event);
  
  		dev_dbg(cpts->dev, "CPTS_EV: %d high:%08X low:%08x\n",
  			type, event->high, event->low);
  		switch (type) {
  		case CPTS_EV_PUSH:
  			WRITE_ONCE(cpts->cur_timestamp, lo);
  			timecounter_read(&cpts->tc);
  			if (cpts->mult_new) {
  				cpts->cc.mult = cpts->mult_new;
  				cpts->mult_new = 0;
  			}
  			if (!cpts->irq_poll)
  				complete(&cpts->ts_push_complete);
  			break;
  		case CPTS_EV_TX:
  		case CPTS_EV_RX:
  			event->tmo = jiffies +
  				msecs_to_jiffies(CPTS_EVENT_RX_TX_TIMEOUT);
  
  			list_del_init(&event->list);
  			list_add_tail(&event->list, &cpts->events);
  			need_schedule = true;
  			break;
  		case CPTS_EV_ROLL:
  		case CPTS_EV_HALF:
  			break;
  		case CPTS_EV_HW:
  			pevent.timestamp = event->timestamp;
  			pevent.type = PTP_CLOCK_EXTTS;
  			pevent.index = cpts_event_port(event) - 1;
  			ptp_clock_event(cpts->clock, &pevent);
  			break;
  		default:
  			dev_err(cpts->dev, "cpts: unknown event type\n");
  			break;
  		}
  		if (type == match)
  			break;
  	}
  
  	spin_unlock_irqrestore(&cpts->lock, flags);
  
  	if (!cpts->irq_poll && need_schedule)
  		ptp_schedule_worker(cpts->clock, 0);
  
  	return type == match ? 0 : -1;
  }
  
  void cpts_misc_interrupt(struct cpts *cpts)
  {
  	cpts_fifo_read(cpts, -1);
  }
  EXPORT_SYMBOL_GPL(cpts_misc_interrupt);
  
  static u64 cpts_systim_read(const struct cyclecounter *cc)
  {
  	struct cpts *cpts = container_of(cc, struct cpts, cc);
  
  	return READ_ONCE(cpts->cur_timestamp);
  }
  
  static void cpts_update_cur_time(struct cpts *cpts, int match,
  				 struct ptp_system_timestamp *sts)
  {
  	unsigned long flags;
  
  	reinit_completion(&cpts->ts_push_complete);
  
  	/* use spin_lock_irqsave() here as it has to run very fast */
  	spin_lock_irqsave(&cpts->lock, flags);
  	ptp_read_system_prets(sts);
  	cpts_write32(cpts, TS_PUSH, ts_push);
  	cpts_read32(cpts, ts_push);
  	ptp_read_system_postts(sts);
  	spin_unlock_irqrestore(&cpts->lock, flags);
  
  	if (cpts->irq_poll && cpts_fifo_read(cpts, match) && match != -1)
  		dev_err(cpts->dev, "cpts: unable to obtain a time stamp\n");
  
  	if (!cpts->irq_poll &&
  	    !wait_for_completion_timeout(&cpts->ts_push_complete, HZ))
  		dev_err(cpts->dev, "cpts: obtain a time stamp timeout\n");
  }
  
  /* PTP clock operations */
  
  static int cpts_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
  {
  	struct cpts *cpts = container_of(ptp, struct cpts, info);
  	int neg_adj = 0;
  	u32 diff, mult;
  	u64 adj;
  
  	if (ppb < 0) {
  		neg_adj = 1;
  		ppb = -ppb;
  	}
  	mult = cpts->cc_mult;
  	adj = mult;
  	adj *= ppb;
  	diff = div_u64(adj, 1000000000ULL);
  
  	mutex_lock(&cpts->ptp_clk_mutex);
  
  	cpts->mult_new = neg_adj ? mult - diff : mult + diff;
  
  	cpts_update_cur_time(cpts, CPTS_EV_PUSH, NULL);
  
  	mutex_unlock(&cpts->ptp_clk_mutex);
  	return 0;
  }
  
  static int cpts_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
  {
  	struct cpts *cpts = container_of(ptp, struct cpts, info);
  
  	mutex_lock(&cpts->ptp_clk_mutex);
  	timecounter_adjtime(&cpts->tc, delta);
  	mutex_unlock(&cpts->ptp_clk_mutex);
  
  	return 0;
  }
  
  static int cpts_ptp_gettimeex(struct ptp_clock_info *ptp,
  			      struct timespec64 *ts,
  			      struct ptp_system_timestamp *sts)
  {
  	struct cpts *cpts = container_of(ptp, struct cpts, info);
  	u64 ns;
  
  	mutex_lock(&cpts->ptp_clk_mutex);
  
  	cpts_update_cur_time(cpts, CPTS_EV_PUSH, sts);
  
  	ns = timecounter_read(&cpts->tc);
  	mutex_unlock(&cpts->ptp_clk_mutex);
  
  	*ts = ns_to_timespec64(ns);
  
  	return 0;
  }
  
  static int cpts_ptp_settime(struct ptp_clock_info *ptp,
  			    const struct timespec64 *ts)
  {
  	struct cpts *cpts = container_of(ptp, struct cpts, info);
  	u64 ns;
  
  	ns = timespec64_to_ns(ts);
  
  	mutex_lock(&cpts->ptp_clk_mutex);
  	timecounter_init(&cpts->tc, &cpts->cc, ns);
  	mutex_unlock(&cpts->ptp_clk_mutex);
  
  	return 0;
  }
  
  static int cpts_extts_enable(struct cpts *cpts, u32 index, int on)
  {
  	u32 v;
  
  	if (((cpts->hw_ts_enable & BIT(index)) >> index) == on)
  		return 0;
  
  	mutex_lock(&cpts->ptp_clk_mutex);
  
  	v = cpts_read32(cpts, control);
  	if (on) {
  		v |= BIT(8 + index);
  		cpts->hw_ts_enable |= BIT(index);
  	} else {
  		v &= ~BIT(8 + index);
  		cpts->hw_ts_enable &= ~BIT(index);
  	}
  	cpts_write32(cpts, v, control);
  
  	mutex_unlock(&cpts->ptp_clk_mutex);
  
  	return 0;
  }
  
  static int cpts_ptp_enable(struct ptp_clock_info *ptp,
  			   struct ptp_clock_request *rq, int on)
  {
  	struct cpts *cpts = container_of(ptp, struct cpts, info);
  
  	switch (rq->type) {
  	case PTP_CLK_REQ_EXTTS:
  		return cpts_extts_enable(cpts, rq->extts.index, on);
  	default:
  		break;
  	}
  
  	return -EOPNOTSUPP;
  }
  
  static bool cpts_match_tx_ts(struct cpts *cpts, struct cpts_event *event)
  {
  	struct sk_buff_head txq_list;
  	struct sk_buff *skb, *tmp;
  	unsigned long flags;
  	bool found = false;
  	u32 mtype_seqid;
  
  	mtype_seqid = event->high &
  		      ((MESSAGE_TYPE_MASK << MESSAGE_TYPE_SHIFT) |
  		       (SEQUENCE_ID_MASK << SEQUENCE_ID_SHIFT) |
  		       (EVENT_TYPE_MASK << EVENT_TYPE_SHIFT));
  
  	__skb_queue_head_init(&txq_list);
  
  	spin_lock_irqsave(&cpts->txq.lock, flags);
  	skb_queue_splice_init(&cpts->txq, &txq_list);
  	spin_unlock_irqrestore(&cpts->txq.lock, flags);
  
  	skb_queue_walk_safe(&txq_list, skb, tmp) {
  		struct skb_shared_hwtstamps ssh;
  		struct cpts_skb_cb_data *skb_cb =
  					(struct cpts_skb_cb_data *)skb->cb;
  
  		if (mtype_seqid == skb_cb->skb_mtype_seqid) {
  			memset(&ssh, 0, sizeof(ssh));
  			ssh.hwtstamp = ns_to_ktime(event->timestamp);
  			skb_tstamp_tx(skb, &ssh);
  			found = true;
  			__skb_unlink(skb, &txq_list);
  			dev_consume_skb_any(skb);
  			dev_dbg(cpts->dev, "match tx timestamp mtype_seqid %08x\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, &txq_list);
  			dev_consume_skb_any(skb);
  		}
  	}
  
  	spin_lock_irqsave(&cpts->txq.lock, flags);
  	skb_queue_splice(&txq_list, &cpts->txq);
  	spin_unlock_irqrestore(&cpts->txq.lock, flags);
  
  	return found;
  }
  
  static void cpts_process_events(struct cpts *cpts)
  {
  	struct list_head *this, *next;
  	struct cpts_event *event;
  	LIST_HEAD(events_free);
  	unsigned long flags;
  	LIST_HEAD(events);
  
  	spin_lock_irqsave(&cpts->lock, flags);
  	list_splice_init(&cpts->events, &events);
  	spin_unlock_irqrestore(&cpts->lock, flags);
  
  	list_for_each_safe(this, next, &events) {
  		event = list_entry(this, struct cpts_event, list);
  		if (cpts_match_tx_ts(cpts, event) ||
  		    time_after(jiffies, event->tmo)) {
  			list_del_init(&event->list);
  			list_add(&event->list, &events_free);
  		}
  	}
  
  	spin_lock_irqsave(&cpts->lock, flags);
  	list_splice_tail(&events, &cpts->events);
  	list_splice_tail(&events_free, &cpts->pool);
  	spin_unlock_irqrestore(&cpts->lock, flags);
  }
  
  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;
  	unsigned long flags;
  	u64 ns;
  
  	mutex_lock(&cpts->ptp_clk_mutex);
  
  	cpts_update_cur_time(cpts, -1, NULL);
  	ns = timecounter_read(&cpts->tc);
  
  	cpts_process_events(cpts);
  
  	spin_lock_irqsave(&cpts->txq.lock, flags);
  	if (!skb_queue_empty(&cpts->txq)) {
  		cpts_purge_txq(cpts);
  		if (!skb_queue_empty(&cpts->txq))
  			delay = CPTS_SKB_TX_WORK_TIMEOUT;
  	}
  	spin_unlock_irqrestore(&cpts->txq.lock, flags);
  
  	dev_dbg(cpts->dev, "cpts overflow check at %lld\n", ns);
  	mutex_unlock(&cpts->ptp_clk_mutex);
  	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,
  	.gettimex64	= cpts_ptp_gettimeex,
  	.settime64	= cpts_ptp_settime,
  	.enable		= cpts_ptp_enable,
  	.do_aux_work	= cpts_overflow_check,
  };
  
  static int cpts_skb_get_mtype_seqid(struct sk_buff *skb, u32 *mtype_seqid)
  {
  	unsigned int ptp_class = ptp_classify_raw(skb);
  	struct ptp_header *hdr;
  	u8 msgtype;
  	u16 seqid;
  
  	if (ptp_class == PTP_CLASS_NONE)
  		return 0;
  
  	hdr = ptp_parse_header(skb, ptp_class);
  	if (!hdr)
  		return 0;
  
  	msgtype = ptp_get_msgtype(hdr, ptp_class);
  	seqid	= ntohs(hdr->sequence_id);
  
  	*mtype_seqid  = (msgtype & MESSAGE_TYPE_MASK) << MESSAGE_TYPE_SHIFT;
  	*mtype_seqid |= (seqid & SEQUENCE_ID_MASK) << SEQUENCE_ID_SHIFT;
  
  	return 1;
  }
  
  static u64 cpts_find_ts(struct cpts *cpts, struct sk_buff *skb,
  			int ev_type, u32 skb_mtype_seqid)
  {
  	struct list_head *this, *next;
  	struct cpts_event *event;
  	unsigned long flags;
  	u32 mtype_seqid;
  	u64 ns = 0;
  
  	cpts_fifo_read(cpts, -1);
  	spin_lock_irqsave(&cpts->lock, flags);
  	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_seqid = event->high &
  			      ((MESSAGE_TYPE_MASK << MESSAGE_TYPE_SHIFT) |
  			       (SEQUENCE_ID_MASK << SEQUENCE_ID_SHIFT) |
  			       (EVENT_TYPE_MASK << EVENT_TYPE_SHIFT));
  
  		if (mtype_seqid == skb_mtype_seqid) {
  			ns = event->timestamp;
  			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)
  {
  	struct cpts_skb_cb_data *skb_cb = (struct cpts_skb_cb_data *)skb->cb;
  	struct skb_shared_hwtstamps *ssh;
  	int ret;
  	u64 ns;
  
  	/* cpts_rx_timestamp() is called before eth_type_trans(), so
  	 * skb MAC Hdr properties are not configured yet. Hence need to
  	 * reset skb MAC header here
  	 */
  	skb_reset_mac_header(skb);
  	ret = cpts_skb_get_mtype_seqid(skb, &skb_cb->skb_mtype_seqid);
  	if (!ret)
  		return;
  
  	skb_cb->skb_mtype_seqid |= (CPTS_EV_RX << EVENT_TYPE_SHIFT);
  
  	dev_dbg(cpts->dev, "%s mtype seqid %08x\n",
  		__func__, skb_cb->skb_mtype_seqid);
  
  	ns = cpts_find_ts(cpts, skb, CPTS_EV_RX, skb_cb->skb_mtype_seqid);
  	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)
  {
  	struct cpts_skb_cb_data *skb_cb = (struct cpts_skb_cb_data *)skb->cb;
  	int ret;
  
  	if (!(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
  		return;
  
  	ret = cpts_skb_get_mtype_seqid(skb, &skb_cb->skb_mtype_seqid);
  	if (!ret)
  		return;
  
  	skb_cb->skb_mtype_seqid |= (CPTS_EV_TX << EVENT_TYPE_SHIFT);
  
  	dev_dbg(cpts->dev, "%s mtype seqid %08x\n",
  		__func__, skb_cb->skb_mtype_seqid);
  
  	/* Always defer TX TS processing to PTP worker */
  	skb_get(skb);
  	/* get the timestamp for timeouts */
  	skb_cb->tmo = jiffies + msecs_to_jiffies(CPTS_SKB_RX_TX_TMO);
  	skb_queue_tail(&cpts->txq, skb);
  	ptp_schedule_worker(cpts->clock, 0);
  }
  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);
  
  	clk_enable(cpts->refclk);
  
  	cpts_write32(cpts, CPTS_EN, control);
  	cpts_write32(cpts, TS_PEND_EN, int_enable);
  
  	timecounter_init(&cpts->tc, &cpts->cc, ktime_get_real_ns());
  
  	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_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_mux_clk_setup(struct cpts *cpts, struct device_node *node)
  {
  	struct device_node *refclk_np;
  	const char **parent_names;
  	unsigned int num_parents;
  	struct clk_hw *clk_hw;
  	int ret = -EINVAL;
  	u32 *mux_table;
  
  	refclk_np = of_get_child_by_name(node, "cpts-refclk-mux");
  	if (!refclk_np)
  		/* refclk selection supported not for all SoCs */
  		return 0;
  
  	num_parents = of_clk_get_parent_count(refclk_np);
  	if (num_parents < 1) {
  		dev_err(cpts->dev, "mux-clock %s must have parents\n",
  			refclk_np->name);
  		goto mux_fail;
  	}
  
  	parent_names = devm_kzalloc(cpts->dev, (sizeof(char *) * num_parents),
  				    GFP_KERNEL);
  
  	mux_table = devm_kzalloc(cpts->dev, sizeof(*mux_table) * num_parents,
  				 GFP_KERNEL);
  	if (!mux_table || !parent_names) {
  		ret = -ENOMEM;
  		goto mux_fail;
  	}
  
  	of_clk_parent_fill(refclk_np, parent_names, num_parents);
  
  	ret = of_property_read_variable_u32_array(refclk_np, "ti,mux-tbl",
  						  mux_table,
  						  num_parents, num_parents);
  	if (ret < 0)
  		goto mux_fail;
  
  	clk_hw = clk_hw_register_mux_table(cpts->dev, refclk_np->name,
  					   parent_names, num_parents,
  					   0,
  					   &cpts->reg->rftclk_sel, 0, 0x1F,
  					   0, mux_table, NULL);
  	if (IS_ERR(clk_hw)) {
  		ret = PTR_ERR(clk_hw);
  		goto mux_fail;
  	}
  
  	ret = devm_add_action_or_reset(cpts->dev,
  				       (void(*)(void *))clk_hw_unregister_mux,
  				       clk_hw);
  	if (ret) {
  		dev_err(cpts->dev, "add clkmux unreg action %d", ret);
  		goto mux_fail;
  	}
  
  	ret = of_clk_add_hw_provider(refclk_np, of_clk_hw_simple_get, clk_hw);
  	if (ret)
  		goto mux_fail;
  
  	ret = devm_add_action_or_reset(cpts->dev,
  				       (void(*)(void *))of_clk_del_provider,
  				       refclk_np);
  	if (ret) {
  		dev_err(cpts->dev, "add clkmux provider unreg action %d", ret);
  		goto mux_fail;
  	}
  
  	return ret;
  
  mux_fail:
  	of_node_put(refclk_np);
  	return ret;
  }
  
  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 cpts_of_mux_clk_setup(cpts, node);
  
  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, u32 n_ext_ts)
  {
  	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;
  	cpts->irq_poll = true;
  	spin_lock_init(&cpts->lock);
  	mutex_init(&cpts->ptp_clk_mutex);
  	init_completion(&cpts->ts_push_complete);
  
  	ret = cpts_of_parse(cpts, node);
  	if (ret)
  		return ERR_PTR(ret);
  
  	cpts->refclk = devm_get_clk_from_child(dev, node, "cpts");
  	if (IS_ERR(cpts->refclk))
  		/* try get clk from dev node for compatibility */
  		cpts->refclk = devm_clk_get(dev, "cpts");
  
  	if (IS_ERR(cpts->refclk)) {
  		dev_err(dev, "Failed to get cpts refclk %ld\n",
  			PTR_ERR(cpts->refclk));
  		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;
  
  	if (n_ext_ts)
  		cpts->info.n_ext_ts = n_ext_ts;
  
  	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 <richardcochran@gmail.com>");
  