[mirror_ubuntu-artful-kernel.git] / drivers / net / ethernet / ti / cpts.c

/*
 * 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"

#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);
		} else if (time_after(jiffies, skb_cb->tmo)) {
			/* timeout any expired skbs over 1s */
			dev_dbg(cpts->dev,
				"expiring tx timestamp mtype %u seqid %04x\n",
				mtype, seqid);
			__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;
			}
		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.%09lu\n", ts.tv_sec, ts.tv_nsec);
	return (long)delay;
}

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,
	.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);

	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_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_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_PTR(PTR_ERR(cpts->refclk));
	}

	clk_prepare(cpts->refclk);

	cpts->cc.read = cpts_systim_read;
	cpts->cc.mask = CLOCKSOURCE_MASK(32);
	cpts->info = cpts_info;

	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>");
Commit	Line	Data
87c0e764 RC	1	/*
	2	* TI Common Platform Time Sync
	3	*
	4	* Copyright (C) 2012 Richard Cochran <richardcochran@gmail.com>
	5	*
	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.
	10	*
	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.
	15	*
	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
	19	*/
	20	#include <linux/err.h>
	21	#include <linux/if.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>
79eb9d28 AS	29	#include <linux/if_ether.h>
79eb9d28 AS	30	#include <linux/if_vlan.h>
87c0e764	31
87c0e764 RC	32	#include "cpts.h"
87c0e764 RC	33
0d5f54fe GS	34	#define CPTS_SKB_TX_WORK_TIMEOUT 1 /* jiffies */
	35
	36	struct cpts_skb_cb_data {
	37	unsigned long tmo;
	38	};
	39
391fd6ca GS	40	#define cpts_read32(c, r) readl_relaxed(&c->reg->r)
391fd6ca GS	41	#define cpts_write32(c, v, r) writel_relaxed(v, &c->reg->r)
87c0e764	42
0d5f54fe GS	43	static int cpts_match(struct sk_buff *skb, unsigned int ptp_class,
	44	u16 ts_seqid, u8 ts_msgtype);
	45
87c0e764 RC	46	static int event_expired(struct cpts_event *event)
	47	{
	48	return time_after(jiffies, event->tmo);
	49	}
	50
	51	static int event_type(struct cpts_event *event)
	52	{
	53	return (event->high >> EVENT_TYPE_SHIFT) & EVENT_TYPE_MASK;
	54	}
	55
	56	static int cpts_fifo_pop(struct cpts cpts, u32 high, u32 *low)
	57	{
	58	u32 r = cpts_read32(cpts, intstat_raw);
	59
	60	if (r & TS_PEND_RAW) {
	61	*high = cpts_read32(cpts, event_high);
	62	*low = cpts_read32(cpts, event_low);
	63	cpts_write32(cpts, EVENT_POP, event_pop);
	64	return 0;
	65	}
	66	return -1;
	67	}
	68
e4439fa8 WK	69	static int cpts_purge_events(struct cpts *cpts)
	70	{
	71	struct list_head this, next;
	72	struct cpts_event *event;
	73	int removed = 0;
	74
	75	list_for_each_safe(this, next, &cpts->events) {
	76	event = list_entry(this, struct cpts_event, list);
	77	if (event_expired(event)) {
	78	list_del_init(&event->list);
	79	list_add(&event->list, &cpts->pool);
	80	++removed;
	81	}
	82	}
	83
	84	if (removed)
	85	pr_debug("cpts: event pool cleaned up %d\n", removed);
	86	return removed ? 0 : -1;
	87	}
	88
0d5f54fe GS	89	static bool cpts_match_tx_ts(struct cpts cpts, struct cpts_event event)
	90	{
	91	struct sk_buff skb, tmp;
	92	u16 seqid;
	93	u8 mtype;
	94	bool found = false;
	95
	96	mtype = (event->high >> MESSAGE_TYPE_SHIFT) & MESSAGE_TYPE_MASK;
	97	seqid = (event->high >> SEQUENCE_ID_SHIFT) & SEQUENCE_ID_MASK;
	98
	99	/* no need to grab txq.lock as access is always done under cpts->lock */
	100	skb_queue_walk_safe(&cpts->txq, skb, tmp) {
	101	struct skb_shared_hwtstamps ssh;
	102	unsigned int class = ptp_classify_raw(skb);
	103	struct cpts_skb_cb_data *skb_cb =
	104	(struct cpts_skb_cb_data *)skb->cb;
	105
	106	if (cpts_match(skb, class, seqid, mtype)) {
	107	u64 ns = timecounter_cyc2time(&cpts->tc, event->low);
	108
	109	memset(&ssh, 0, sizeof(ssh));
	110	ssh.hwtstamp = ns_to_ktime(ns);
	111	skb_tstamp_tx(skb, &ssh);
	112	found = true;
	113	__skb_unlink(skb, &cpts->txq);
	114	dev_consume_skb_any(skb);
	115	dev_dbg(cpts->dev, "match tx timestamp mtype %u seqid %04x\n",
	116	mtype, seqid);
	117	} else if (time_after(jiffies, skb_cb->tmo)) {
	118	/* timeout any expired skbs over 1s */
	119	dev_dbg(cpts->dev,
	120	"expiring tx timestamp mtype %u seqid %04x\n",
	121	mtype, seqid);
	122	__skb_unlink(skb, &cpts->txq);
	123	dev_consume_skb_any(skb);
	124	}
	125	}
	126
	127	return found;
	128	}
	129
87c0e764 RC	130	/*
	131	* Returns zero if matching event type was found.
	132	*/
	133	static int cpts_fifo_read(struct cpts *cpts, int match)
	134	{
	135	int i, type = -1;
	136	u32 hi, lo;
	137	struct cpts_event *event;
	138
	139	for (i = 0; i < CPTS_FIFO_DEPTH; i++) {
	140	if (cpts_fifo_pop(cpts, &hi, &lo))
	141	break;
e4439fa8 WK	142
	143	if (list_empty(&cpts->pool) && cpts_purge_events(cpts)) {
	144	pr_err("cpts: event pool empty\n");
87c0e764 RC	145	return -1;
87c0e764 RC	146	}
e4439fa8	147
87c0e764 RC	148	event = list_first_entry(&cpts->pool, struct cpts_event, list);
	149	event->tmo = jiffies + 2;
	150	event->high = hi;
	151	event->low = lo;
	152	type = event_type(event);
	153	switch (type) {
0d5f54fe GS	154	case CPTS_EV_TX:
	155	if (cpts_match_tx_ts(cpts, event)) {
	156	/* if the new event matches an existing skb,
	157	* then don't queue it
	158	*/
	159	break;
	160	}
87c0e764 RC	161	case CPTS_EV_PUSH:
87c0e764 RC	162	case CPTS_EV_RX:
87c0e764 RC	163	list_del_init(&event->list);
	164	list_add_tail(&event->list, &cpts->events);
	165	break;
	166	case CPTS_EV_ROLL:
	167	case CPTS_EV_HALF:
	168	case CPTS_EV_HW:
	169	break;
	170	default:
07f42258	171	pr_err("cpts: unknown event type\n");
87c0e764 RC	172	break;
	173	}
	174	if (type == match)
	175	break;
	176	}
	177	return type == match ? 0 : -1;
	178	}
	179
a5a1d1c2	180	static u64 cpts_systim_read(const struct cyclecounter *cc)
87c0e764 RC	181	{
	182	u64 val = 0;
	183	struct cpts_event *event;
	184	struct list_head this, next;
	185	struct cpts *cpts = container_of(cc, struct cpts, cc);
	186
	187	cpts_write32(cpts, TS_PUSH, ts_push);
	188	if (cpts_fifo_read(cpts, CPTS_EV_PUSH))
	189	pr_err("cpts: unable to obtain a time stamp\n");
	190
	191	list_for_each_safe(this, next, &cpts->events) {
	192	event = list_entry(this, struct cpts_event, list);
	193	if (event_type(event) == CPTS_EV_PUSH) {
	194	list_del_init(&event->list);
	195	list_add(&event->list, &cpts->pool);
	196	val = event->low;
	197	break;
	198	}
	199	}
	200
	201	return val;
	202	}
	203
	204	/* PTP clock operations */
	205
	206	static int cpts_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
	207	{
	208	u64 adj;
	209	u32 diff, mult;
	210	int neg_adj = 0;
	211	unsigned long flags;
	212	struct cpts *cpts = container_of(ptp, struct cpts, info);
	213
	214	if (ppb < 0) {
	215	neg_adj = 1;
	216	ppb = -ppb;
	217	}
	218	mult = cpts->cc_mult;
	219	adj = mult;
	220	adj *= ppb;
	221	diff = div_u64(adj, 1000000000ULL);
	222
	223	spin_lock_irqsave(&cpts->lock, flags);
	224
	225	timecounter_read(&cpts->tc);
	226
	227	cpts->cc.mult = neg_adj ? mult - diff : mult + diff;
	228
	229	spin_unlock_irqrestore(&cpts->lock, flags);
	230
	231	return 0;
	232	}
	233
	234	static int cpts_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
	235	{
87c0e764 RC	236	unsigned long flags;
	237	struct cpts *cpts = container_of(ptp, struct cpts, info);
	238
	239	spin_lock_irqsave(&cpts->lock, flags);
f25a30be	240	timecounter_adjtime(&cpts->tc, delta);
87c0e764 RC	241	spin_unlock_irqrestore(&cpts->lock, flags);
	242
	243	return 0;
	244	}
	245
a5c79c26	246	static int cpts_ptp_gettime(struct ptp_clock_info ptp, struct timespec64 ts)
87c0e764 RC	247	{
87c0e764 RC	248	u64 ns;
87c0e764 RC	249	unsigned long flags;
	250	struct cpts *cpts = container_of(ptp, struct cpts, info);
	251
	252	spin_lock_irqsave(&cpts->lock, flags);
	253	ns = timecounter_read(&cpts->tc);
	254	spin_unlock_irqrestore(&cpts->lock, flags);
	255
84d923ce	256	*ts = ns_to_timespec64(ns);
87c0e764 RC	257
	258	return 0;
	259	}
	260
	261	static int cpts_ptp_settime(struct ptp_clock_info *ptp,
a5c79c26	262	const struct timespec64 *ts)
87c0e764 RC	263	{
	264	u64 ns;
	265	unsigned long flags;
	266	struct cpts *cpts = container_of(ptp, struct cpts, info);
	267
84d923ce	268	ns = timespec64_to_ns(ts);
87c0e764 RC	269
	270	spin_lock_irqsave(&cpts->lock, flags);
	271	timecounter_init(&cpts->tc, &cpts->cc, ns);
	272	spin_unlock_irqrestore(&cpts->lock, flags);
	273
	274	return 0;
	275	}
	276
	277	static int cpts_ptp_enable(struct ptp_clock_info *ptp,
	278	struct ptp_clock_request *rq, int on)
	279	{
	280	return -EOPNOTSUPP;
	281	}
	282
999f1292 GS	283	static long cpts_overflow_check(struct ptp_clock_info *ptp)
	284	{
	285	struct cpts *cpts = container_of(ptp, struct cpts, info);
	286	unsigned long delay = cpts->ov_check_period;
	287	struct timespec64 ts;
0d5f54fe GS	288	unsigned long flags;
	289
	290	spin_lock_irqsave(&cpts->lock, flags);
	291	ts = ns_to_timespec64(timecounter_read(&cpts->tc));
	292
	293	if (!skb_queue_empty(&cpts->txq))
	294	delay = CPTS_SKB_TX_WORK_TIMEOUT;
	295	spin_unlock_irqrestore(&cpts->lock, flags);
999f1292	296
999f1292 GS	297	pr_debug("cpts overflow check at %lld.%09lu\n", ts.tv_sec, ts.tv_nsec);
	298	return (long)delay;
	299	}
	300
87c0e764 RC	301	static struct ptp_clock_info cpts_info = {
	302	.owner = THIS_MODULE,
	303	.name = "CTPS timer",
	304	.max_adj = 1000000,
	305	.n_ext_ts = 0,
4986b4f0	306	.n_pins = 0,
87c0e764 RC	307	.pps = 0,
	308	.adjfreq = cpts_ptp_adjfreq,
	309	.adjtime = cpts_ptp_adjtime,
a5c79c26 RC	310	.gettime64 = cpts_ptp_gettime,
a5c79c26 RC	311	.settime64 = cpts_ptp_settime,
87c0e764	312	.enable = cpts_ptp_enable,
999f1292	313	.do_aux_work = cpts_overflow_check,
87c0e764 RC	314	};
87c0e764 RC	315
87c0e764 RC	316	static int cpts_match(struct sk_buff *skb, unsigned int ptp_class,
	317	u16 ts_seqid, u8 ts_msgtype)
	318	{
	319	u16 *seqid;
ae5c6c6d	320	unsigned int offset = 0;
87c0e764 RC	321	u8 msgtype, data = skb->data;
87c0e764 RC	322
ae5c6c6d SS	323	if (ptp_class & PTP_CLASS_VLAN)
	324	offset += VLAN_HLEN;
	325
	326	switch (ptp_class & PTP_CLASS_PMASK) {
	327	case PTP_CLASS_IPV4:
cca04b28	328	offset += ETH_HLEN + IPV4_HLEN(data + offset) + UDP_HLEN;
87c0e764	329	break;
ae5c6c6d SS	330	case PTP_CLASS_IPV6:
ae5c6c6d SS	331	offset += ETH_HLEN + IP6_HLEN + UDP_HLEN;
87c0e764	332	break;
ae5c6c6d SS	333	case PTP_CLASS_L2:
ae5c6c6d SS	334	offset += ETH_HLEN;
87c0e764 RC	335	break;
	336	default:
	337	return 0;
	338	}
	339
	340	if (skb->len + ETH_HLEN < offset + OFF_PTP_SEQUENCE_ID + sizeof(*seqid))
	341	return 0;
	342
	343	if (unlikely(ptp_class & PTP_CLASS_V1))
	344	msgtype = data + offset + OFF_PTP_CONTROL;
	345	else
	346	msgtype = data + offset;
	347
	348	seqid = (u16 *)(data + offset + OFF_PTP_SEQUENCE_ID);
	349
	350	return (ts_msgtype == (msgtype & 0xf) && ts_seqid == ntohs(seqid));
	351	}
	352
	353	static u64 cpts_find_ts(struct cpts cpts, struct sk_buff skb, int ev_type)
	354	{
	355	u64 ns = 0;
	356	struct cpts_event *event;
	357	struct list_head this, next;
164d8c66	358	unsigned int class = ptp_classify_raw(skb);
87c0e764 RC	359	unsigned long flags;
	360	u16 seqid;
	361	u8 mtype;
	362
	363	if (class == PTP_CLASS_NONE)
	364	return 0;
	365
	366	spin_lock_irqsave(&cpts->lock, flags);
a93439cc	367	cpts_fifo_read(cpts, -1);
87c0e764 RC	368	list_for_each_safe(this, next, &cpts->events) {
	369	event = list_entry(this, struct cpts_event, list);
	370	if (event_expired(event)) {
	371	list_del_init(&event->list);
	372	list_add(&event->list, &cpts->pool);
	373	continue;
	374	}
	375	mtype = (event->high >> MESSAGE_TYPE_SHIFT) & MESSAGE_TYPE_MASK;
	376	seqid = (event->high >> SEQUENCE_ID_SHIFT) & SEQUENCE_ID_MASK;
	377	if (ev_type == event_type(event) &&
	378	cpts_match(skb, class, seqid, mtype)) {
	379	ns = timecounter_cyc2time(&cpts->tc, event->low);
	380	list_del_init(&event->list);
	381	list_add(&event->list, &cpts->pool);
	382	break;
	383	}
	384	}
0d5f54fe GS	385
	386	if (ev_type == CPTS_EV_TX && !ns) {
	387	struct cpts_skb_cb_data *skb_cb =
	388	(struct cpts_skb_cb_data *)skb->cb;
	389	/* Not found, add frame to queue for processing later.
	390	* The periodic FIFO check will handle this.
	391	*/
	392	skb_get(skb);
	393	/* get the timestamp for timeouts */
	394	skb_cb->tmo = jiffies + msecs_to_jiffies(100);
	395	__skb_queue_tail(&cpts->txq, skb);
	396	ptp_schedule_worker(cpts->clock, 0);
	397	}
87c0e764 RC	398	spin_unlock_irqrestore(&cpts->lock, flags);
	399
	400	return ns;
	401	}
	402
	403	void cpts_rx_timestamp(struct cpts cpts, struct sk_buff skb)
	404	{
	405	u64 ns;
	406	struct skb_shared_hwtstamps *ssh;
	407
	408	if (!cpts->rx_enable)
	409	return;
	410	ns = cpts_find_ts(cpts, skb, CPTS_EV_RX);
	411	if (!ns)
	412	return;
	413	ssh = skb_hwtstamps(skb);
	414	memset(ssh, 0, sizeof(*ssh));
	415	ssh->hwtstamp = ns_to_ktime(ns);
	416	}
c8395d4e	417	EXPORT_SYMBOL_GPL(cpts_rx_timestamp);
87c0e764 RC	418
	419	void cpts_tx_timestamp(struct cpts cpts, struct sk_buff skb)
	420	{
	421	u64 ns;
	422	struct skb_shared_hwtstamps ssh;
	423
	424	if (!(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
	425	return;
	426	ns = cpts_find_ts(cpts, skb, CPTS_EV_TX);
	427	if (!ns)
	428	return;
	429	memset(&ssh, 0, sizeof(ssh));
	430	ssh.hwtstamp = ns_to_ktime(ns);
	431	skb_tstamp_tx(skb, &ssh);
	432	}
c8395d4e	433	EXPORT_SYMBOL_GPL(cpts_tx_timestamp);
87c0e764	434
8a2c9a5a	435	int cpts_register(struct cpts *cpts)
87c0e764	436	{
87c0e764	437	int err, i;
87c0e764	438
0d5f54fe	439	skb_queue_head_init(&cpts->txq);
87c0e764 RC	440	INIT_LIST_HEAD(&cpts->events);
	441	INIT_LIST_HEAD(&cpts->pool);
	442	for (i = 0; i < CPTS_MAX_EVENTS; i++)
	443	list_add(&cpts->pool_data[i].list, &cpts->pool);
	444
8a2c9a5a GS	445	clk_enable(cpts->refclk);
8a2c9a5a GS	446
87c0e764 RC	447	cpts_write32(cpts, CPTS_EN, control);
	448	cpts_write32(cpts, TS_PEND_EN, int_enable);
	449
87c0e764	450	timecounter_init(&cpts->tc, &cpts->cc, ktime_to_ns(ktime_get_real()));
87c0e764	451
8a2c9a5a	452	cpts->clock = ptp_clock_register(&cpts->info, cpts->dev);
6c691405 GS	453	if (IS_ERR(cpts->clock)) {
	454	err = PTR_ERR(cpts->clock);
	455	cpts->clock = NULL;
	456	goto err_ptp;
	457	}
87c0e764	458	cpts->phc_index = ptp_clock_index(cpts->clock);
6c691405	459
999f1292	460	ptp_schedule_worker(cpts->clock, cpts->ov_check_period);
87c0e764	461	return 0;
6c691405 GS	462
6c691405 GS	463	err_ptp:
8a2c9a5a	464	clk_disable(cpts->refclk);
6c691405	465	return err;
87c0e764	466	}
c8395d4e	467	EXPORT_SYMBOL_GPL(cpts_register);
87c0e764 RC	468
	469	void cpts_unregister(struct cpts *cpts)
	470	{
8a2c9a5a GS	471	if (WARN_ON(!cpts->clock))
	472	return;
	473
8a2c9a5a GS	474	ptp_clock_unregister(cpts->clock);
8a2c9a5a GS	475	cpts->clock = NULL;
8fcd6891 GS	476
	477	cpts_write32(cpts, 0, int_enable);
	478	cpts_write32(cpts, 0, control);
	479
0d5f54fe GS	480	/* Drop all packet */
	481	skb_queue_purge(&cpts->txq);
	482
8a2c9a5a	483	clk_disable(cpts->refclk);
87c0e764	484	}
c8395d4e GS	485	EXPORT_SYMBOL_GPL(cpts_unregister);
c8395d4e GS	486
88f0f0b0 GS	487	static void cpts_calc_mult_shift(struct cpts *cpts)
	488	{
	489	u64 frac, maxsec, ns;
	490	u32 freq;
	491
	492	freq = clk_get_rate(cpts->refclk);
	493
	494	/* Calc the maximum number of seconds which we can run before
	495	* wrapping around.
	496	*/
	497	maxsec = cpts->cc.mask;
	498	do_div(maxsec, freq);
	499	/* limit conversation rate to 10 sec as higher values will produce
	500	* too small mult factors and so reduce the conversion accuracy
	501	*/
	502	if (maxsec > 10)
	503	maxsec = 10;
	504
20138cf9 GS	505	/* Calc overflow check period (maxsec / 2) */
	506	cpts->ov_check_period = (HZ * maxsec) / 2;
	507	dev_info(cpts->dev, "cpts: overflow check period %lu (jiffies)\n",
	508	cpts->ov_check_period);
	509
88f0f0b0 GS	510	if (cpts->cc.mult \|\| cpts->cc.shift)
	511	return;
	512
	513	clocks_calc_mult_shift(&cpts->cc.mult, &cpts->cc.shift,
	514	freq, NSEC_PER_SEC, maxsec);
	515
	516	frac = 0;
	517	ns = cyclecounter_cyc2ns(&cpts->cc, freq, cpts->cc.mask, &frac);
	518
	519	dev_info(cpts->dev,
	520	"CPTS: ref_clk_freq:%u calc_mult:%u calc_shift:%u error:%lld nsec/sec\n",
	521	freq, cpts->cc.mult, cpts->cc.shift, (ns - NSEC_PER_SEC));
	522	}
	523
4a88fb95 GS	524	static int cpts_of_parse(struct cpts cpts, struct device_node node)
	525	{
	526	int ret = -EINVAL;
	527	u32 prop;
	528
88f0f0b0 GS	529	if (!of_property_read_u32(node, "cpts_clock_mult", &prop))
88f0f0b0 GS	530	cpts->cc.mult = prop;
4a88fb95	531
88f0f0b0 GS	532	if (!of_property_read_u32(node, "cpts_clock_shift", &prop))
	533	cpts->cc.shift = prop;
	534
	535	if ((cpts->cc.mult && !cpts->cc.shift) \|\|
	536	(!cpts->cc.mult && cpts->cc.shift))
	537	goto of_error;
4a88fb95 GS	538
	539	return 0;
	540
	541	of_error:
	542	dev_err(cpts->dev, "CPTS: Missing property in the DT.\n");
	543	return ret;
	544	}
	545
8a2c9a5a	546	struct cpts cpts_create(struct device dev, void __iomem *regs,
4a88fb95	547	struct device_node *node)
8a2c9a5a GS	548	{
8a2c9a5a GS	549	struct cpts *cpts;
4a88fb95	550	int ret;
8a2c9a5a GS	551
	552	cpts = devm_kzalloc(dev, sizeof(*cpts), GFP_KERNEL);
	553	if (!cpts)
	554	return ERR_PTR(-ENOMEM);
	555
	556	cpts->dev = dev;
	557	cpts->reg = (struct cpsw_cpts __iomem *)regs;
	558	spin_lock_init(&cpts->lock);
8a2c9a5a	559
4a88fb95 GS	560	ret = cpts_of_parse(cpts, node);
	561	if (ret)
	562	return ERR_PTR(ret);
	563
8a2c9a5a GS	564	cpts->refclk = devm_clk_get(dev, "cpts");
	565	if (IS_ERR(cpts->refclk)) {
	566	dev_err(dev, "Failed to get cpts refclk\n");
	567	return ERR_PTR(PTR_ERR(cpts->refclk));
	568	}
	569
	570	clk_prepare(cpts->refclk);
	571
	572	cpts->cc.read = cpts_systim_read;
	573	cpts->cc.mask = CLOCKSOURCE_MASK(32);
88f0f0b0 GS	574	cpts->info = cpts_info;
	575
	576	cpts_calc_mult_shift(cpts);
4a88fb95 GS	577	/* save cc.mult original value as it can be modified
	578	* by cpts_ptp_adjfreq().
	579	*/
	580	cpts->cc_mult = cpts->cc.mult;
8a2c9a5a GS	581
	582	return cpts;
	583	}
	584	EXPORT_SYMBOL_GPL(cpts_create);
	585
	586	void cpts_release(struct cpts *cpts)
	587	{
	588	if (!cpts)
	589	return;
	590
	591	if (WARN_ON(!cpts->refclk))
	592	return;
	593
	594	clk_unprepare(cpts->refclk);
	595	}
	596	EXPORT_SYMBOL_GPL(cpts_release);
	597
c8395d4e GS	598	MODULE_LICENSE("GPL v2");
	599	MODULE_DESCRIPTION("TI CPTS driver");
	600	MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");