can: etas_es58x: add devlink support

Add basic support for devlink at the device level. The callbacks of
struct devlink_ops will be implemented next.
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20221130174658.29282-2-mailhol.vincent@wanadoo.frSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/usb/Kconfig

@@ -30,6 +30,7 @@ config CAN_ESD_USB
 config CAN_ETAS_ES58X
 	tristate "ETAS ES58X CAN/USB interfaces"
 	select CRC16
+	select NET_DEVLINK
 	help
 	  This driver supports the ES581.4, ES582.1 and ES584.1 interfaces
 	  from ETAS GmbH (https://www.etas.com/en/products/es58x.php).

drivers/net/can/usb/etas_es58x/Makefile

 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_CAN_ETAS_ES58X) += etas_es58x.o
-etas_es58x-y = es58x_core.o es581_4.o es58x_fd.o
+etas_es58x-y = es58x_core.o es58x_devlink.o es581_4.o es58x_fd.o

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

@@ -16,6 +16,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/usb.h>
+#include <net/devlink.h>
 
 #include "es58x_core.h"
 
@@ -2177,6 +2178,7 @@ static struct es58x_device *es58x_init_es58x_dev(struct usb_interface *intf,
 {
 	struct device *dev = &intf->dev;
 	struct es58x_device *es58x_dev;
+	struct devlink *devlink;
 	const struct es58x_parameters *param;
 	const struct es58x_operators *ops;
 	struct usb_device *udev = interface_to_usbdev(intf);
@@ -2199,11 +2201,12 @@ static struct es58x_device *es58x_init_es58x_dev(struct usb_interface *intf,
 		ops = &es581_4_ops;
 	}
 
-	es58x_dev = devm_kzalloc(dev, es58x_sizeof_es58x_device(param),
-				 GFP_KERNEL);
-	if (!es58x_dev)
+	devlink = devlink_alloc(&es58x_dl_ops, es58x_sizeof_es58x_device(param),
+				dev);
+	if (!devlink)
 		return ERR_PTR(-ENOMEM);
 
+	es58x_dev = devlink_priv(devlink);
 	es58x_dev->param = param;
 	es58x_dev->ops = ops;
 	es58x_dev->dev = dev;
@@ -2250,6 +2253,8 @@ static int es58x_probe(struct usb_interface *intf,
 	if (ret)
 		return ret;
 
+	devlink_register(priv_to_devlink(es58x_dev));
+
 	for (ch_idx = 0; ch_idx < es58x_dev->num_can_ch; ch_idx++) {
 		ret = es58x_init_netdev(es58x_dev, ch_idx);
 		if (ret) {
@@ -2275,8 +2280,10 @@ static void es58x_disconnect(struct usb_interface *intf)
 	dev_info(&intf->dev, "Disconnecting %s %s\n",
 		 es58x_dev->udev->manufacturer, es58x_dev->udev->product);
 
+	devlink_unregister(priv_to_devlink(es58x_dev));
 	es58x_free_netdevs(es58x_dev);
 	es58x_free_urbs(es58x_dev);
+	devlink_free(priv_to_devlink(es58x_dev));
 	usb_set_intfdata(intf, NULL);
 }
 

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

@@ -674,6 +674,7 @@ static inline enum es58x_flag es58x_get_flags(const struct sk_buff *skb)
 	return es58x_flags;
 }
 
+/* es58x_core.c. */
 int es58x_can_get_echo_skb(struct net_device *netdev, u32 packet_idx,
 			   u64 *tstamps, unsigned int pkts);
 int es58x_tx_ack_msg(struct net_device *netdev, u16 tx_free_entries,
@@ -691,9 +692,14 @@ int es58x_rx_cmd_ret_u32(struct net_device *netdev,
 int es58x_send_msg(struct es58x_device *es58x_dev, u8 cmd_type, u8 cmd_id,
 		   const void *msg, u16 cmd_len, int channel_idx);
 
+/* es58x_devlink.c. */
+extern const struct devlink_ops es58x_dl_ops;
+
+/* es581_4.c. */
 extern const struct es58x_parameters es581_4_param;
 extern const struct es58x_operators es581_4_ops;
 
+/* es58x_fd.c. */
 extern const struct es58x_parameters es58x_fd_param;
 extern const struct es58x_operators es58x_fd_ops;
 

drivers/net/can/usb/etas_es58x/es58x_devlink.c

+// SPDX-License-Identifier: GPL-2.0
+
+/* Driver for ETAS GmbH ES58X USB CAN(-FD) Bus Interfaces.
+ *
+ * File es58x_devlink.c: report the product information using devlink.
+ *
+ * Copyright (c) 2022 Vincent Mailhol <mailhol.vincent@wanadoo.fr>
+ */
+
+#include <net/devlink.h>
+
+const struct devlink_ops es58x_dl_ops = {
+};