can: kvaser_usb: Add devlink port support

Register each CAN channel of the device as an devlink physical port.
This makes it easier to get device information for a given network
interface (i.e. can2).

Example output:
  $ devlink dev
  usb/1-1.3:1.0

  $ devlink port
  usb/1-1.3:1.0/0: type eth netdev can0 flavour physical port 0 splittable false
  usb/1-1.3:1.0/1: type eth netdev can1 flavour physical port 1 splittable false

  $ devlink port show can1
  usb/1-1.3:1.0/1: type eth netdev can1 flavour physical port 0 splittable false

  $ devlink dev info
  usb/1-1.3:1.0:
    driver kvaser_usb
    serial_number 1020
    versions:
        fixed:
          board.rev 1
          board.id 7330130009653
        running:
          fw 3.22.527

  $ ethtool -i can1
  driver: kvaser_usb
  version: 6.12.10-arch1-1
  firmware-version: 3.22.527
  expansion-rom-version:
  bus-info: 1-1.3:1.0
  supports-statistics: no
  supports-test: no
  supports-eeprom-access: no
  supports-register-dump: no
  supports-priv-flags: no

Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Jimmy Assarsson <extja@kvaser.com>
Link: https://patch.msgid.link/20250725123452.41-11-extja@kvaser.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

Author: Jimmy Assarsson

drivers/net/can/usb/kvaser_usb/kvaser_usb.h

@@ -131,6 +131,7 @@ struct kvaser_usb {
 
 struct kvaser_usb_net_priv {
 	struct can_priv can;
+	struct devlink_port devlink_port;
 	struct can_berr_counter bec;
 
 	/* subdriver-specific data */
@@ -229,6 +230,9 @@ extern const struct kvaser_usb_dev_ops kvaser_usb_leaf_dev_ops;
 
 extern const struct devlink_ops kvaser_usb_devlink_ops;
 
+int kvaser_usb_devlink_port_register(struct kvaser_usb_net_priv *priv);
+void kvaser_usb_devlink_port_unregister(struct kvaser_usb_net_priv *priv);
+
 void kvaser_usb_unlink_tx_urbs(struct kvaser_usb_net_priv *priv);
 
 int kvaser_usb_recv_cmd(const struct kvaser_usb *dev, void *cmd, int len,

drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c

@@ -818,6 +818,7 @@ static void kvaser_usb_remove_interfaces(struct kvaser_usb *dev)
 		if (ops->dev_remove_channel)
 			ops->dev_remove_channel(priv);
 
+		kvaser_usb_devlink_port_unregister(priv);
 		free_candev(priv->netdev);
 	}
 }
@@ -891,20 +892,28 @@ static int kvaser_usb_init_one(struct kvaser_usb *dev, int channel)
 	if (ops->dev_init_channel) {
 		err = ops->dev_init_channel(priv);
 		if (err)
-			goto err;
+			goto candev_free;
+	}
+
+	err = kvaser_usb_devlink_port_register(priv);
+	if (err) {
+		dev_err(&dev->intf->dev, "Failed to register devlink port\n");
+		goto candev_free;
 	}
 
 	err = register_candev(netdev);
 	if (err) {
 		dev_err(&dev->intf->dev, "Failed to register CAN device\n");
-		goto err;
+		goto unregister_devlink_port;
 	}
 
 	netdev_dbg(netdev, "device registered\n");
 
 	return 0;
 
-err:
+unregister_devlink_port:
+	kvaser_usb_devlink_port_unregister(priv);
+candev_free:
 	free_candev(netdev);
 	dev->nets[channel] = NULL;
 	return err;

drivers/net/can/usb/kvaser_usb/kvaser_usb_devlink.c

@@ -5,6 +5,7 @@
  */
 #include "kvaser_usb.h"
 
+#include <linux/netdevice.h>
 #include <net/devlink.h>
 
 #define KVASER_USB_EAN_MSB 0x00073301
@@ -60,3 +61,27 @@ static int kvaser_usb_devlink_info_get(struct devlink *devlink,
 const struct devlink_ops kvaser_usb_devlink_ops = {
 	.info_get = kvaser_usb_devlink_info_get,
 };
+
+int kvaser_usb_devlink_port_register(struct kvaser_usb_net_priv *priv)
+{
+	int ret;
+	struct devlink_port_attrs attrs = {
+		.flavour = DEVLINK_PORT_FLAVOUR_PHYSICAL,
+		.phys.port_number = priv->channel,
+	};
+	devlink_port_attrs_set(&priv->devlink_port, &attrs);
+
+	ret = devlink_port_register(priv_to_devlink(priv->dev),
+				    &priv->devlink_port, priv->channel);
+	if (ret)
+		return ret;
+
+	SET_NETDEV_DEVLINK_PORT(priv->netdev, &priv->devlink_port);
+
+	return 0;
+}
+
+void kvaser_usb_devlink_port_unregister(struct kvaser_usb_net_priv *priv)
+{
+	devlink_port_unregister(&priv->devlink_port);
+}