can: kvaser_usb: advertise timestamping capabilities and add ioctl support

Currently, userland has no method to query which timestamping features
are supported by the kvaser_usb driver (aside maybe of getting RX
messages and observe whether or not hardware timestamps stay at zero).

The canonical way for a network driver to advertise what kind of
timestamping it supports is to implement
ethtool_ops::get_ts_info(). Here, we use the CAN specific
can_ethtool_op_get_ts_info_hwts() function to achieve this.

In addition, the driver currently does not support the hardware
timestamps ioctls. According to [1], SIOCSHWTSTAMP is "must" and
SIOCGHWTSTAMP is "should". This patch fills up that gap by
implementing net_device_ops::ndo_eth_ioctl() using the CAN specific
function can_eth_ioctl_hwts().

[1] kernel doc Timestamping, section 3.1: "Hardware Timestamping
Implementation: Device Drivers"
Link: https://docs.kernel.org/networking/timestamping.html#hardware-timestamping-implementation-device-drivers
CC: Jimmy Assarsson <extja@kvaser.com>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20220727101641.198847-13-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb.h b/drivers/net/can/usb/kvaser_usb/kvaser_usb.h
index eefcbe3aadce752ea513a8501bc38aa776dd2a17..841da29cef939b363be58aaffa36458e9857cb35 100644 (file)
--- a/drivers/net/can/usb/kvaser_usb/kvaser_usb.h
+++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb.h
@@ -39,6 +39,7 @@
 #define KVASER_USB_QUIRK_HAS_SILENT_MODE       BIT(0)
 #define KVASER_USB_QUIRK_HAS_TXRX_ERRORS       BIT(1)
 #define KVASER_USB_QUIRK_IGNORE_CLK_FREQ       BIT(2)
+#define KVASER_USB_QUIRK_HAS_HARDWARE_TIMESTAMP        BIT(3)
 
 /* Device capabilities */
 #define KVASER_USB_CAP_BERR_CAP                        0x01

diff --git a/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c b/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
index ce60b16ac8eea7f0f39811f54f87331b2107cb5b..824cab80aa02fc979a20ff98ca9b24f264e1e9b2 100644 (file)
--- a/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
+++ b/drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c
@@ -13,6 +13,7 @@
 
 #include <linux/completion.h>
 #include <linux/device.h>
+#include <linux/ethtool.h>
 #include <linux/gfp.h>
 #include <linux/if.h>
 #include <linux/kernel.h>
@@ -89,7 +90,7 @@
 #define USB_HYBRID_PRO_CANLIN_PRODUCT_ID       278
 
 static const struct kvaser_usb_driver_info kvaser_usb_driver_info_hydra = {
-       .quirks = 0,
+       .quirks = KVASER_USB_QUIRK_HAS_HARDWARE_TIMESTAMP,
        .ops = &kvaser_usb_hydra_dev_ops,
 };
 
@@ -665,6 +666,22 @@ static const struct net_device_ops kvaser_usb_netdev_ops = {
        .ndo_change_mtu = can_change_mtu,
 };
 
+static const struct net_device_ops kvaser_usb_netdev_ops_hwts = {
+       .ndo_open = kvaser_usb_open,
+       .ndo_stop = kvaser_usb_close,
+       .ndo_eth_ioctl = can_eth_ioctl_hwts,
+       .ndo_start_xmit = kvaser_usb_start_xmit,
+       .ndo_change_mtu = can_change_mtu,
+};
+
+static const struct ethtool_ops kvaser_usb_ethtool_ops = {
+       .get_ts_info = ethtool_op_get_ts_info,
+};
+
+static const struct ethtool_ops kvaser_usb_ethtool_ops_hwts = {
+       .get_ts_info = can_ethtool_op_get_ts_info_hwts,
+};
+
 static void kvaser_usb_remove_interfaces(struct kvaser_usb *dev)
 {
        int i;
@@ -742,7 +759,13 @@ static int kvaser_usb_init_one(struct kvaser_usb *dev, int channel)
        netdev->flags |= IFF_ECHO;
 
        netdev->netdev_ops = &kvaser_usb_netdev_ops;
-
+       if (driver_info->quirks & KVASER_USB_QUIRK_HAS_HARDWARE_TIMESTAMP) {
+               netdev->netdev_ops = &kvaser_usb_netdev_ops_hwts;
+               netdev->ethtool_ops = &kvaser_usb_ethtool_ops_hwts;
+       } else {
+               netdev->netdev_ops = &kvaser_usb_netdev_ops;
+               netdev->ethtool_ops = &kvaser_usb_ethtool_ops;
+       }
        SET_NETDEV_DEV(netdev, &dev->intf->dev);
        netdev->dev_id = channel;