[PATCH v4 11/14] can: kvaser_pciefd: advertise timestamping capabilities and add ioctl support

[Vincent Mailhol <mailhol.vincent@wanadoo.fr>]

Currently, userland has no method to query which timestamping features
are supported by the kvaser_pciefd 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>
---
 drivers/net/can/kvaser_pciefd.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/can/kvaser_pciefd.c b/drivers/net/can/kvaser_pciefd.c
index dcd2c9d50d5e..ed54c0b3c7d4 100644
--- a/drivers/net/can/kvaser_pciefd.c
+++ b/drivers/net/can/kvaser_pciefd.c
@@ -9,6 +9,7 @@
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/device.h>
+#include <linux/ethtool.h>
 #include <linux/pci.h>
 #include <linux/can/dev.h>
 #include <linux/timer.h>
@@ -919,10 +920,15 @@ static void kvaser_pciefd_bec_poll_timer(struct timer_list *data)
 static const struct net_device_ops kvaser_pciefd_netdev_ops = {
 	.ndo_open = kvaser_pciefd_open,
 	.ndo_stop = kvaser_pciefd_stop,
+	.ndo_eth_ioctl = can_eth_ioctl_hwts,
 	.ndo_start_xmit = kvaser_pciefd_start_xmit,
 	.ndo_change_mtu = can_change_mtu,
 };
 
+static const struct ethtool_ops kvaser_pciefd_ethtool_ops = {
+	.get_ts_info = can_ethtool_op_get_ts_info_hwts,
+};
+
 static int kvaser_pciefd_setup_can_ctrls(struct kvaser_pciefd *pcie)
 {
 	int i;
@@ -939,6 +945,7 @@ static int kvaser_pciefd_setup_can_ctrls(struct kvaser_pciefd *pcie)
 
 		can = netdev_priv(netdev);
 		netdev->netdev_ops = &kvaser_pciefd_netdev_ops;
+		netdev->ethtool_ops = &kvaser_pciefd_ethtool_ops;
 		can->reg_base = pcie->reg_base + KVASER_PCIEFD_KCAN0_BASE +
 				i * KVASER_PCIEFD_KCAN_BASE_OFFSET;
 
-- 
2.35.1