1 files changed, 609 insertions, 0 deletions

diff --git a/drivers/net/ethernet/ti/cpts.c b/drivers/net/ethernet/ti/cpts.c
new file mode 100644
index 000000000..01cc92f6a
--- /dev/null
+++ b/drivers/net/ethernet/ti/cpts.c
@@ -0,0 +1,609 @@
+/*
+ * 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);
+			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 <richardcochran@gmail.com>");