1 files changed, 295 insertions, 0 deletions
diff --git a/drivers/ptp/ptp_vclock.c b/drivers/ptp/ptp_vclock.c
new file mode 100644
index 000000000000..1c0ed4805c0a
--- /dev/null
+++ b/drivers/ptp/ptp_vclock.c
@@ -0,0 +1,295 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * PTP virtual clock driver
+ *
+ * Copyright 2021 NXP
+ */
+#include <linux/slab.h>
+#include <linux/hashtable.h>
+#include "ptp_private.h"
+
+#define PTP_VCLOCK_CC_SHIFT		31
+#define PTP_VCLOCK_CC_MULT		(1 << PTP_VCLOCK_CC_SHIFT)
+#define PTP_VCLOCK_FADJ_SHIFT		9
+#define PTP_VCLOCK_FADJ_DENOMINATOR	15625ULL
+#define PTP_VCLOCK_REFRESH_INTERVAL	(HZ * 2)
+
+/* protects vclock_hash addition/deletion */
+static DEFINE_SPINLOCK(vclock_hash_lock);
+
+static DEFINE_READ_MOSTLY_HASHTABLE(vclock_hash, 8);
+
+static void ptp_vclock_hash_add(struct ptp_vclock *vclock)
+{
+	spin_lock(&vclock_hash_lock);
+
+	hlist_add_head_rcu(&vclock->vclock_hash_node,
+			   &vclock_hash[vclock->clock->index % HASH_SIZE(vclock_hash)]);
+
+	spin_unlock(&vclock_hash_lock);
+}
+
+static void ptp_vclock_hash_del(struct ptp_vclock *vclock)
+{
+	spin_lock(&vclock_hash_lock);
+
+	hlist_del_init_rcu(&vclock->vclock_hash_node);
+
+	spin_unlock(&vclock_hash_lock);
+
+	synchronize_rcu();
+}
+
+static int ptp_vclock_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
+{
+	struct ptp_vclock *vclock = info_to_vclock(ptp);
+	unsigned long flags;
+	s64 adj;
+
+	adj = (s64)scaled_ppm << PTP_VCLOCK_FADJ_SHIFT;
+	adj = div_s64(adj, PTP_VCLOCK_FADJ_DENOMINATOR);
+
+	spin_lock_irqsave(&vclock->lock, flags);
+	timecounter_read(&vclock->tc);
+	vclock->cc.mult = PTP_VCLOCK_CC_MULT + adj;
+	spin_unlock_irqrestore(&vclock->lock, flags);
+
+	return 0;
+}
+
+static int ptp_vclock_adjtime(struct ptp_clock_info *ptp, s64 delta)
+{
+	struct ptp_vclock *vclock = info_to_vclock(ptp);
+	unsigned long flags;
+
+	spin_lock_irqsave(&vclock->lock, flags);
+	timecounter_adjtime(&vclock->tc, delta);
+	spin_unlock_irqrestore(&vclock->lock, flags);
+
+	return 0;
+}
+
+static int ptp_vclock_gettime(struct ptp_clock_info *ptp,
+			      struct timespec64 *ts)
+{
+	struct ptp_vclock *vclock = info_to_vclock(ptp);
+	unsigned long flags;
+	u64 ns;
+
+	spin_lock_irqsave(&vclock->lock, flags);
+	ns = timecounter_read(&vclock->tc);
+	spin_unlock_irqrestore(&vclock->lock, flags);
+	*ts = ns_to_timespec64(ns);
+
+	return 0;
+}
+
+static int ptp_vclock_gettimex(struct ptp_clock_info *ptp,
+			       struct timespec64 *ts,
+			       struct ptp_system_timestamp *sts)
+{
+	struct ptp_vclock *vclock = info_to_vclock(ptp);
+	struct ptp_clock *pptp = vclock->pclock;
+	struct timespec64 pts;
+	unsigned long flags;
+	int err;
+	u64 ns;
+
+	err = pptp->info->getcyclesx64(pptp->info, &pts, sts);
+	if (err)
+		return err;
+
+	spin_lock_irqsave(&vclock->lock, flags);
+	ns = timecounter_cyc2time(&vclock->tc, timespec64_to_ns(&pts));
+	spin_unlock_irqrestore(&vclock->lock, flags);
+
+	*ts = ns_to_timespec64(ns);
+
+	return 0;
+}
+
+static int ptp_vclock_settime(struct ptp_clock_info *ptp,
+			      const struct timespec64 *ts)
+{
+	struct ptp_vclock *vclock = info_to_vclock(ptp);
+	u64 ns = timespec64_to_ns(ts);
+	unsigned long flags;
+
+	spin_lock_irqsave(&vclock->lock, flags);
+	timecounter_init(&vclock->tc, &vclock->cc, ns);
+	spin_unlock_irqrestore(&vclock->lock, flags);
+
+	return 0;
+}
+
+static int ptp_vclock_getcrosststamp(struct ptp_clock_info *ptp,
+				     struct system_device_crosststamp *xtstamp)
+{
+	struct ptp_vclock *vclock = info_to_vclock(ptp);
+	struct ptp_clock *pptp = vclock->pclock;
+	unsigned long flags;
+	int err;
+	u64 ns;
+
+	err = pptp->info->getcrosscycles(pptp->info, xtstamp);
+	if (err)
+		return err;
+
+	spin_lock_irqsave(&vclock->lock, flags);
+	ns = timecounter_cyc2time(&vclock->tc, ktime_to_ns(xtstamp->device));
+	spin_unlock_irqrestore(&vclock->lock, flags);
+
+	xtstamp->device = ns_to_ktime(ns);
+
+	return 0;
+}
+
+static long ptp_vclock_refresh(struct ptp_clock_info *ptp)
+{
+	struct ptp_vclock *vclock = info_to_vclock(ptp);
+	struct timespec64 ts;
+
+	ptp_vclock_gettime(&vclock->info, &ts);
+
+	return PTP_VCLOCK_REFRESH_INTERVAL;
+}
+
+static const struct ptp_clock_info ptp_vclock_info = {
+	.owner		= THIS_MODULE,
+	.name		= "ptp virtual clock",
+	.max_adj	= 500000000,
+	.adjfine	= ptp_vclock_adjfine,
+	.adjtime	= ptp_vclock_adjtime,
+	.settime64	= ptp_vclock_settime,
+	.do_aux_work	= ptp_vclock_refresh,
+};
+
+static u64 ptp_vclock_read(const struct cyclecounter *cc)
+{
+	struct ptp_vclock *vclock = cc_to_vclock(cc);
+	struct ptp_clock *ptp = vclock->pclock;
+	struct timespec64 ts = {};
+
+	ptp->info->getcycles64(ptp->info, &ts);
+
+	return timespec64_to_ns(&ts);
+}
+
+static const struct cyclecounter ptp_vclock_cc = {
+	.read	= ptp_vclock_read,
+	.mask	= CYCLECOUNTER_MASK(32),
+	.mult	= PTP_VCLOCK_CC_MULT,
+	.shift	= PTP_VCLOCK_CC_SHIFT,
+};
+
+struct ptp_vclock *ptp_vclock_register(struct ptp_clock *pclock)
+{
+	struct ptp_vclock *vclock;
+
+	vclock = kzalloc(sizeof(*vclock), GFP_KERNEL);
+	if (!vclock)
+		return NULL;
+
+	vclock->pclock = pclock;
+	vclock->info = ptp_vclock_info;
+	if (pclock->info->getcyclesx64)
+		vclock->info.gettimex64 = ptp_vclock_gettimex;
+	else
+		vclock->info.gettime64 = ptp_vclock_gettime;
+	if (pclock->info->getcrosscycles)
+		vclock->info.getcrosststamp = ptp_vclock_getcrosststamp;
+	vclock->cc = ptp_vclock_cc;
+
+	snprintf(vclock->info.name, PTP_CLOCK_NAME_LEN, "ptp%d_virt",
+		 pclock->index);
+
+	INIT_HLIST_NODE(&vclock->vclock_hash_node);
+
+	spin_lock_init(&vclock->lock);
+
+	vclock->clock = ptp_clock_register(&vclock->info, &pclock->dev);
+	if (IS_ERR_OR_NULL(vclock->clock)) {
+		kfree(vclock);
+		return NULL;
+	}
+
+	timecounter_init(&vclock->tc, &vclock->cc, 0);
+	ptp_schedule_worker(vclock->clock, PTP_VCLOCK_REFRESH_INTERVAL);
+
+	ptp_vclock_hash_add(vclock);
+
+	return vclock;
+}
+
+void ptp_vclock_unregister(struct ptp_vclock *vclock)
+{
+	ptp_vclock_hash_del(vclock);
+
+	ptp_clock_unregister(vclock->clock);
+	kfree(vclock);
+}
+
+#if IS_BUILTIN(CONFIG_PTP_1588_CLOCK)
+int ptp_get_vclocks_index(int pclock_index, int **vclock_index)
+{
+	char name[PTP_CLOCK_NAME_LEN] = "";
+	struct ptp_clock *ptp;
+	struct device *dev;
+	int num = 0;
+
+	if (pclock_index < 0)
+		return num;
+
+	snprintf(name, PTP_CLOCK_NAME_LEN, "ptp%d", pclock_index);
+	dev = class_find_device_by_name(ptp_class, name);
+	if (!dev)
+		return num;
+
+	ptp = dev_get_drvdata(dev);
+
+	if (mutex_lock_interruptible(&ptp->n_vclocks_mux)) {
+		put_device(dev);
+		return num;
+	}
+
+	*vclock_index = kzalloc(sizeof(int) * ptp->n_vclocks, GFP_KERNEL);
+	if (!(*vclock_index))
+		goto out;
+
+	memcpy(*vclock_index, ptp->vclock_index, sizeof(int) * ptp->n_vclocks);
+	num = ptp->n_vclocks;
+out:
+	mutex_unlock(&ptp->n_vclocks_mux);
+	put_device(dev);
+	return num;
+}
+EXPORT_SYMBOL(ptp_get_vclocks_index);
+
+ktime_t ptp_convert_timestamp(const ktime_t *hwtstamp, int vclock_index)
+{
+	unsigned int hash = vclock_index % HASH_SIZE(vclock_hash);
+	struct ptp_vclock *vclock;
+	unsigned long flags;
+	u64 ns;
+	u64 vclock_ns = 0;
+
+	ns = ktime_to_ns(*hwtstamp);
+
+	rcu_read_lock();
+
+	hlist_for_each_entry_rcu(vclock, &vclock_hash[hash], vclock_hash_node) {
+		if (vclock->clock->index != vclock_index)
+			continue;
+
+		spin_lock_irqsave(&vclock->lock, flags);
+		vclock_ns = timecounter_cyc2time(&vclock->tc, ns);
+		spin_unlock_irqrestore(&vclock->lock, flags);
+		break;
+	}
+
+	rcu_read_unlock();
+
+	return ns_to_ktime(vclock_ns);
+}
+EXPORT_SYMBOL(ptp_convert_timestamp);
+#endif