[PATCH v1 23/24] can: peak_canfd: 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 peak_canfd driver (aside maybe of getting RX
messages and obseverse whever 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: Stephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
---
 drivers/net/can/peak_canfd/peak_canfd.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/can/peak_canfd/peak_canfd.c b/drivers/net/can/peak_canfd/peak_canfd.c
index 9b94d5b4be2d..b0915cc80cc8 100644
--- a/drivers/net/can/peak_canfd/peak_canfd.c
+++ b/drivers/net/can/peak_canfd/peak_canfd.c
@@ -746,6 +746,7 @@ static netdev_tx_t peak_canfd_start_xmit(struct sk_buff *skb,
 static const struct net_device_ops peak_canfd_netdev_ops = {
 	.ndo_open = peak_canfd_open,
 	.ndo_stop = peak_canfd_close,
+	.ndo_eth_ioctl = can_eth_ioctl_hwts,
 	.ndo_start_xmit = peak_canfd_start_xmit,
 	.ndo_change_mtu = can_change_mtu,
 };
@@ -758,6 +759,7 @@ static void peak_canfd_get_drvinfo(struct net_device *netdev,
 
 static const struct ethtool_ops peak_canfd_ethtool_ops = {
 	.get_drvinfo = peak_canfd_get_drvinfo,
+	.get_ts_info = can_ethtool_op_get_ts_info_hwts,
 };
 
 struct net_device *alloc_peak_canfd_dev(int sizeof_priv, int index,
-- 
2.35.1