can: peak_usb: add support of ethtool set_phys_id()

This patch makes it possible to specifically flash the LED of a CAN
port of the CAN-USB interfaces of PEAK-System.

Link: https://lore.kernel.org/r/20210309122141.3276927-1-mkl@pengutronix.deSigned-off-by: Stephane Grosjean <s.grosjean@peak-system.com>
[mkl: use common prefix PCAN_ for defines]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/usb/peak_usb/pcan_usb.c

@@ -11,6 +11,7 @@
 #include <linux/netdevice.h>
 #include <linux/usb.h>
 #include <linux/module.h>
+#include <linux/ethtool.h>
 
 #include <linux/can.h>
 #include <linux/can/dev.h>
@@ -40,6 +41,7 @@
 #define PCAN_USB_CMD_REGISTER	9
 #define PCAN_USB_CMD_EXT_VCC	10
 #define PCAN_USB_CMD_ERR_FR	11
+#define PCAN_USB_CMD_LED	12
 
 /* PCAN_USB_CMD_SET_BUS number arg */
 #define PCAN_USB_BUS_XCVER		2
@@ -248,6 +250,15 @@ static int pcan_usb_set_ext_vcc(struct peak_usb_device *dev, u8 onoff)
 	return pcan_usb_send_cmd(dev, PCAN_USB_CMD_EXT_VCC, PCAN_USB_SET, args);
 }
 
+static int pcan_usb_set_led(struct peak_usb_device *dev, u8 onoff)
+{
+	u8 args[PCAN_USB_CMD_ARGS_LEN] = {
+		[0] = !!onoff,
+	};
+
+	return pcan_usb_send_cmd(dev, PCAN_USB_CMD_LED, PCAN_USB_SET, args);
+}
+
 /*
  * set bittiming value to can
  */
@@ -971,6 +982,40 @@ static int pcan_usb_probe(struct usb_interface *intf)
 	return 0;
 }
 
+static int pcan_usb_set_phys_id(struct net_device *netdev,
+				enum ethtool_phys_id_state state)
+{
+	struct peak_usb_device *dev = netdev_priv(netdev);
+	int err = 0;
+
+	switch (state) {
+	case ETHTOOL_ID_ACTIVE:
+		/* call ON/OFF twice a second */
+		return 2;
+
+	case ETHTOOL_ID_OFF:
+		err = pcan_usb_set_led(dev, 0);
+		break;
+
+	case ETHTOOL_ID_ON:
+		fallthrough;
+
+	case ETHTOOL_ID_INACTIVE:
+		/* restore LED default */
+		err = pcan_usb_set_led(dev, 1);
+		break;
+
+	default:
+		break;
+	}
+
+	return err;
+}
+
+static const struct ethtool_ops pcan_usb_ethtool_ops = {
+	.set_phys_id = pcan_usb_set_phys_id,
+};
+
 /*
  * describe the PCAN-USB adapter
  */
@@ -1001,6 +1046,8 @@ const struct peak_usb_adapter pcan_usb = {
 	/* size of device private data */
 	.sizeof_dev_private = sizeof(struct pcan_usb),
 
+	.ethtool_ops = &pcan_usb_ethtool_ops,
+
 	/* timestamps usage */
 	.ts_used_bits = 16,
 	.ts_period = 24575, /* calibration period in ts. */

drivers/net/can/usb/peak_usb/pcan_usb_core.c

@@ -14,6 +14,7 @@
 #include <linux/module.h>
 #include <linux/netdevice.h>
 #include <linux/usb.h>
+#include <linux/ethtool.h>
 
 #include <linux/can.h>
 #include <linux/can/dev.h>
@@ -820,6 +821,9 @@ static int peak_usb_create_dev(const struct peak_usb_adapter *peak_usb_adapter,
 
 	netdev->flags |= IFF_ECHO; /* we support local echo */
 
+	/* add ethtool support */
+	netdev->ethtool_ops = peak_usb_adapter->ethtool_ops;
+
 	init_usb_anchor(&dev->rx_submitted);
 
 	init_usb_anchor(&dev->tx_submitted);

drivers/net/can/usb/peak_usb/pcan_usb_core.h

@@ -46,6 +46,8 @@ struct peak_usb_adapter {
 	const struct can_bittiming_const * const data_bittiming_const;
 	unsigned int ctrl_count;
 
+	const struct ethtool_ops *ethtool_ops;
+
 	int (*intf_probe)(struct usb_interface *intf);
 
 	int (*dev_init)(struct peak_usb_device *dev);

drivers/net/can/usb/peak_usb/pcan_usb_fd.c

@@ -7,6 +7,7 @@
 #include <linux/netdevice.h>
 #include <linux/usb.h>
 #include <linux/module.h>
+#include <linux/ethtool.h>
 
 #include <linux/can.h>
 #include <linux/can/dev.h>
@@ -1006,6 +1007,31 @@ static void pcan_usb_fd_free(struct peak_usb_device *dev)
 	}
 }
 
+/* blink LED's */
+static int pcan_usb_fd_set_phys_id(struct net_device *netdev,
+				   enum ethtool_phys_id_state state)
+{
+	struct peak_usb_device *dev = netdev_priv(netdev);
+	int err = 0;
+
+	switch (state) {
+	case ETHTOOL_ID_ACTIVE:
+		err = pcan_usb_fd_set_can_led(dev, PCAN_UFD_LED_FAST);
+		break;
+	case ETHTOOL_ID_INACTIVE:
+		err = pcan_usb_fd_set_can_led(dev, PCAN_UFD_LED_DEF);
+		break;
+	default:
+		break;
+	}
+
+	return err;
+}
+
+static const struct ethtool_ops pcan_usb_fd_ethtool_ops = {
+	.set_phys_id = pcan_usb_fd_set_phys_id,
+};
+
 /* describes the PCAN-USB FD adapter */
 static const struct can_bittiming_const pcan_usb_fd_const = {
 	.name = "pcan_usb_fd",
@@ -1047,6 +1073,8 @@ const struct peak_usb_adapter pcan_usb_fd = {
 	/* size of device private data */
 	.sizeof_dev_private = sizeof(struct pcan_usb_fd_device),
 
+	.ethtool_ops = &pcan_usb_fd_ethtool_ops,
+
 	/* timestamps usage */
 	.ts_used_bits = 32,
 	.ts_period = 1000000, /* calibration period in ts. */
@@ -1120,6 +1148,8 @@ const struct peak_usb_adapter pcan_usb_chip = {
 	/* size of device private data */
 	.sizeof_dev_private = sizeof(struct pcan_usb_fd_device),
 
+	.ethtool_ops = &pcan_usb_fd_ethtool_ops,
+
 	/* timestamps usage */
 	.ts_used_bits = 32,
 	.ts_period = 1000000, /* calibration period in ts. */
@@ -1193,6 +1223,8 @@ const struct peak_usb_adapter pcan_usb_pro_fd = {
 	/* size of device private data */
 	.sizeof_dev_private = sizeof(struct pcan_usb_fd_device),
 
+	.ethtool_ops = &pcan_usb_fd_ethtool_ops,
+
 	/* timestamps usage */
 	.ts_used_bits = 32,
 	.ts_period = 1000000, /* calibration period in ts. */
@@ -1266,6 +1298,8 @@ const struct peak_usb_adapter pcan_usb_x6 = {
 	/* size of device private data */
 	.sizeof_dev_private = sizeof(struct pcan_usb_fd_device),
 
+	.ethtool_ops = &pcan_usb_fd_ethtool_ops,
+
 	/* timestamps usage */
 	.ts_used_bits = 32,
 	.ts_period = 1000000, /* calibration period in ts. */

drivers/net/can/usb/peak_usb/pcan_usb_pro.c

@@ -9,6 +9,7 @@
 #include <linux/netdevice.h>
 #include <linux/usb.h>
 #include <linux/module.h>
+#include <linux/ethtool.h>
 
 #include <linux/can.h>
 #include <linux/can/dev.h>
@@ -906,7 +907,7 @@ static int pcan_usb_pro_init(struct peak_usb_device *dev)
 	usb_if->dev[dev->ctrl_idx] = dev;
 
 	/* set LED in default state (end of init phase) */
-	pcan_usb_pro_set_led(dev, 0, 1);
+	pcan_usb_pro_set_led(dev, PCAN_USBPRO_LED_DEVICE, 1);
 
 	kfree(bi);
 	kfree(fi);
@@ -990,6 +991,35 @@ int pcan_usb_pro_probe(struct usb_interface *intf)
 	return 0;
 }
 
+static int pcan_usb_pro_set_phys_id(struct net_device *netdev,
+				    enum ethtool_phys_id_state state)
+{
+	struct peak_usb_device *dev = netdev_priv(netdev);
+	int err = 0;
+
+	switch (state) {
+	case ETHTOOL_ID_ACTIVE:
+		/* fast blinking forever */
+		err = pcan_usb_pro_set_led(dev, PCAN_USBPRO_LED_BLINK_FAST,
+					   0xffffffff);
+		break;
+
+	case ETHTOOL_ID_INACTIVE:
+		/* restore LED default */
+		err = pcan_usb_pro_set_led(dev, PCAN_USBPRO_LED_DEVICE, 1);
+		break;
+
+	default:
+		break;
+	}
+
+	return err;
+}
+
+static const struct ethtool_ops pcan_usb_pro_ethtool_ops = {
+	.set_phys_id = pcan_usb_pro_set_phys_id,
+};
+
 /*
  * describe the PCAN-USB Pro adapter
  */
@@ -1018,6 +1048,8 @@ const struct peak_usb_adapter pcan_usb_pro = {
 	/* size of device private data */
 	.sizeof_dev_private = sizeof(struct pcan_usb_pro_device),
 
+	.ethtool_ops = &pcan_usb_pro_ethtool_ops,
+
 	/* timestamps usage */
 	.ts_used_bits = 32,
 	.ts_period = 1000000, /* calibration period in ts. */

drivers/net/can/usb/peak_usb/pcan_usb_pro.h

@@ -115,6 +115,12 @@ struct __packed pcan_usb_pro_devid {
 	__le32 serial_num;
 };
 
+#define PCAN_USBPRO_LED_DEVICE		0x00
+#define PCAN_USBPRO_LED_BLINK_FAST	0x01
+#define PCAN_USBPRO_LED_BLINK_SLOW	0x02
+#define PCAN_USBPRO_LED_ON		0x03
+#define PCAN_USBPRO_LED_OFF		0x04
+
 struct __packed pcan_usb_pro_setled {
 	u8  data_type;
 	u8  channel;