net: dsa: forward hardware timestamping ioctls to switch driver

This patch adds support to the dsa slave network device so that
switch drivers can implement the SIOC[GS]HWTSTAMP ioctls and the
ethtool timestamp-info interface.
Signed-off-by: Brandon Streiff <brandon.streiff@ni.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/dsa.h

@@ -19,6 +19,7 @@
 #include <linux/workqueue.h>
 #include <linux/of.h>
 #include <linux/ethtool.h>
+#include <linux/net_tstamp.h>
 #include <net/devlink.h>
 #include <net/switchdev.h>
 
@@ -367,6 +368,12 @@ struct dsa_switch_ops {
 	int	(*set_wol)(struct dsa_switch *ds, int port,
 			   struct ethtool_wolinfo *w);
 
+	/*
+	 * ethtool timestamp info
+	 */
+	int	(*get_ts_info)(struct dsa_switch *ds, int port,
+			       struct ethtool_ts_info *ts);
+
 	/*
 	 * Suspend and resume
 	 */
@@ -469,6 +476,14 @@ struct dsa_switch_ops {
 					 int port, struct net_device *br);
 	void	(*crosschip_bridge_leave)(struct dsa_switch *ds, int sw_index,
 					  int port, struct net_device *br);
+
+	/*
+	 * PTP functionality
+	 */
+	int	(*port_hwtstamp_get)(struct dsa_switch *ds, int port,
+				     struct ifreq *ifr);
+	int	(*port_hwtstamp_set)(struct dsa_switch *ds, int port,
+				     struct ifreq *ifr);
 };
 
 struct dsa_switch_driver {

net/dsa/slave.c

@@ -255,6 +255,22 @@ dsa_slave_fdb_dump(struct sk_buff *skb, struct netlink_callback *cb,
 
 static int dsa_slave_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 {
+	struct dsa_slave_priv *p = netdev_priv(dev);
+	struct dsa_switch *ds = p->dp->ds;
+	int port = p->dp->index;
+
+	/* Pass through to switch driver if it supports timestamping */
+	switch (cmd) {
+	case SIOCGHWTSTAMP:
+		if (ds->ops->port_hwtstamp_get)
+			return ds->ops->port_hwtstamp_get(ds, port, ifr);
+		break;
+	case SIOCSHWTSTAMP:
+		if (ds->ops->port_hwtstamp_set)
+			return ds->ops->port_hwtstamp_set(ds, port, ifr);
+		break;
+	}
+
 	if (!dev->phydev)
 		return -ENODEV;
 
@@ -918,6 +934,18 @@ static int dsa_slave_set_rxnfc(struct net_device *dev,
 	return ds->ops->set_rxnfc(ds, dp->index, nfc);
 }
 
+static int dsa_slave_get_ts_info(struct net_device *dev,
+				 struct ethtool_ts_info *ts)
+{
+	struct dsa_slave_priv *p = netdev_priv(dev);
+	struct dsa_switch *ds = p->dp->ds;
+
+	if (!ds->ops->get_ts_info)
+		return -EOPNOTSUPP;
+
+	return ds->ops->get_ts_info(ds, p->dp->index, ts);
+}
+
 static const struct ethtool_ops dsa_slave_ethtool_ops = {
 	.get_drvinfo		= dsa_slave_get_drvinfo,
 	.get_regs_len		= dsa_slave_get_regs_len,
@@ -938,6 +966,7 @@ static const struct ethtool_ops dsa_slave_ethtool_ops = {
 	.set_link_ksettings	= phy_ethtool_set_link_ksettings,
 	.get_rxnfc		= dsa_slave_get_rxnfc,
 	.set_rxnfc		= dsa_slave_set_rxnfc,
+	.get_ts_info		= dsa_slave_get_ts_info,
 };
 
 /* legacy way, bypassing the bridge *****************************************/