can: etas_es58x: add devlink port support

Add support for devlink port which extends the devlink support to the
network interface level. For now, the etas_es58x driver will only rely
on the default features that devlink port has to offer and not
implement additional feature ones.
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20221130174658.29282-3-mailhol.vincent@wanadoo.frSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/usb/etas_es58x/es58x_core.c

@@ -2039,10 +2039,16 @@ static int es58x_set_mode(struct net_device *netdev, enum can_mode mode)
  * @es58x_dev: ES58X device.
  * @priv: ES58X private parameters related to the network device.
  * @channel_idx: Index of the network device.
+ *
+ * Return: zero on success, errno if devlink port could not be
+ *	properly registered.
  */
-static void es58x_init_priv(struct es58x_device *es58x_dev,
-			    struct es58x_priv *priv, int channel_idx)
+static int es58x_init_priv(struct es58x_device *es58x_dev,
+			   struct es58x_priv *priv, int channel_idx)
 {
+	struct devlink_port_attrs attrs = {
+		.flavour = DEVLINK_PORT_FLAVOUR_PHYSICAL,
+	};
 	const struct es58x_parameters *param = es58x_dev->param;
 	struct can_priv *can = &priv->can;
 
@@ -2061,6 +2067,10 @@ static void es58x_init_priv(struct es58x_device *es58x_dev,
 	can->state = CAN_STATE_STOPPED;
 	can->ctrlmode_supported = param->ctrlmode_supported;
 	can->do_set_mode = es58x_set_mode;
+
+	devlink_port_attrs_set(&priv->devlink_port, &attrs);
+	return devlink_port_register(priv_to_devlink(es58x_dev),
+				     &priv->devlink_port, channel_idx);
 }
 
 /**
@@ -2084,7 +2094,10 @@ static int es58x_init_netdev(struct es58x_device *es58x_dev, int channel_idx)
 	}
 	SET_NETDEV_DEV(netdev, dev);
 	es58x_dev->netdev[channel_idx] = netdev;
-	es58x_init_priv(es58x_dev, es58x_priv(netdev), channel_idx);
+	ret = es58x_init_priv(es58x_dev, es58x_priv(netdev), channel_idx);
+	if (ret)
+		goto free_candev;
+	SET_NETDEV_DEVLINK_PORT(netdev, &es58x_priv(netdev)->devlink_port);
 
 	netdev->netdev_ops = &es58x_netdev_ops;
 	netdev->ethtool_ops = &es58x_ethtool_ops;
@@ -2092,16 +2105,20 @@ static int es58x_init_netdev(struct es58x_device *es58x_dev, int channel_idx)
 	netdev->dev_port = channel_idx;
 
 	ret = register_candev(netdev);
-	if (ret) {
-		es58x_dev->netdev[channel_idx] = NULL;
-		free_candev(netdev);
-		return ret;
-	}
+	if (ret)
+		goto devlink_port_unregister;
 
 	netdev_queue_set_dql_min_limit(netdev_get_tx_queue(netdev, 0),
 				       es58x_dev->param->dql_min_limit);
 
 	return ret;
+
+ devlink_port_unregister:
+	devlink_port_unregister(&es58x_priv(netdev)->devlink_port);
+ free_candev:
+	es58x_dev->netdev[channel_idx] = NULL;
+	free_candev(netdev);
+	return ret;
 }
 
 /**
@@ -2118,6 +2135,7 @@ static void es58x_free_netdevs(struct es58x_device *es58x_dev)
 		if (!netdev)
 			continue;
 		unregister_candev(netdev);
+		devlink_port_unregister(&es58x_priv(netdev)->devlink_port);
 		es58x_dev->netdev[i] = NULL;
 		free_candev(netdev);
 	}

drivers/net/can/usb/etas_es58x/es58x_core.h

@@ -17,6 +17,7 @@
 #include <linux/netdevice.h>
 #include <linux/types.h>
 #include <linux/usb.h>
+#include <net/devlink.h>
 
 #include "es581_4.h"
 #include "es58x_fd.h"
@@ -230,6 +231,7 @@ union es58x_urb_cmd {
  * @can: struct can_priv must be the first member (Socket CAN relies
  *	on the fact that function netdev_priv() returns a pointer to
  *	a struct can_priv).
+ * @devlink_port: devlink instance for the network interface.
  * @es58x_dev: pointer to the corresponding ES58X device.
  * @tx_urb: Used as a buffer to concatenate the TX messages and to do
  *	a bulk send. Please refer to es58x_start_xmit() for more
@@ -255,6 +257,7 @@ union es58x_urb_cmd {
  */
 struct es58x_priv {
 	struct can_priv can;
+	struct devlink_port devlink_port;
 	struct es58x_device *es58x_dev;
 	struct urb *tx_urb;