drivers/net/ethernet/ti/cpts.c - kernel/bruno - Git at Google

 /*
  * 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>
 #include <linux/if_ether.h>
 #include <linux/if_vlan.h>

 #include "cpts.h"

 #ifdef CONFIG_TI_CPTS

 #define cpts_read32(c, r)	__raw_readl(&c->reg->r)
 #define cpts_write32(c, v, r)	__raw_writel(v, &c->reg->r)

 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:
 			pr_err("cpts: unknown event type\n");
 			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);
 	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 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,
 };

 static void cpts_overflow_check(struct work_struct *work)
 {
 	struct timespec64 ts;
 	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);
 	pr_debug("cpts overflow check at %lld.%09lu\n", ts.tv_sec, ts.tv_nsec);
 	schedule_delayed_work(&cpts->overflow_work, CPTS_OVERFLOW_PERIOD);
 }

 static void cpts_clk_init(struct device *dev, struct cpts *cpts)
 {
 	cpts->refclk = devm_clk_get(dev, "cpts");
 	if (IS_ERR(cpts->refclk)) {
 		dev_err(dev, "Failed to get cpts refclk\n");
 		cpts->refclk = NULL;
 		return;
 	}
 	clk_prepare_enable(cpts->refclk);
 }

 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;
 	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, 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);

 	cpts_clk_init(dev, cpts);
 	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
 }
	/*
	* 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>
	#include <linux/if_ether.h>
	#include <linux/if_vlan.h>

	#include "cpts.h"

	#ifdef CONFIG_TI_CPTS

	#define cpts_read32(c, r) __raw_readl(&c->reg->r)
	#define cpts_write32(c, v, r) __raw_writel(v, &c->reg->r)

	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:
	pr_err("cpts: unknown event type\n");
	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);
	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 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,
	};

	static void cpts_overflow_check(struct work_struct *work)
	{
	struct timespec64 ts;
	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);
	pr_debug("cpts overflow check at %lld.%09lu\n", ts.tv_sec, ts.tv_nsec);
	schedule_delayed_work(&cpts->overflow_work, CPTS_OVERFLOW_PERIOD);
	}

	static void cpts_clk_init(struct device dev, struct cpts cpts)
	{
	cpts->refclk = devm_clk_get(dev, "cpts");
	if (IS_ERR(cpts->refclk)) {
	dev_err(dev, "Failed to get cpts refclk\n");
	cpts->refclk = NULL;
	return;
	}
	clk_prepare_enable(cpts->refclk);
	}

	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;
	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, 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);

	cpts_clk_init(dev, cpts);
	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
	}