can: peak_canfd: advertise timestamping capabilities and add ioctl support

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

The canonical way to add hardware timestamp support is to implement
ethtool_ops::get_ts_info() in order to advertise the timestamping
capabilities and to implement net_device_ops::ndo_eth_ioctl() as
requested in [1]. Currently, the driver only supports hardware RX
timestamps [2] but not hardware TX. For this reason, the generic
function can_ethtool_op_get_ts_info_hwts() and can_eth_ioctl_hwts()
can not be reused and instead this patch adds peak_get_ts_info() and
peak_eth_ioctl().

[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
[2] https://lore.kernel.org/linux-can/20220727084257.brcbbf7lksoeekbr@pengutronix.de/

CC: Stephane Grosjean <s.grosjean@peak-system.com>
Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20220727101641.198847-14-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

diff --git a/drivers/net/can/peak_canfd/peak_canfd.c b/drivers/net/can/peak_canfd/peak_canfd.c
index afb9adb..f8420cc 100644 (file)
--- a/drivers/net/can/peak_canfd/peak_canfd.c
+++ b/drivers/net/can/peak_canfd/peak_canfd.c
@@ -7,6 +7,7 @@
 
 #include <linux/can.h>
 #include <linux/can/dev.h>
+#include <linux/ethtool.h>
 
 #include "peak_canfd_user.h"
 
@@ -742,13 +743,59 @@ static netdev_tx_t peak_canfd_start_xmit(struct sk_buff *skb,
        return NETDEV_TX_OK;
 }
 
+static int peak_eth_ioctl(struct net_device *netdev, struct ifreq *ifr, int cmd)
+{
+       struct hwtstamp_config hwts_cfg = { 0 };
+
+       switch (cmd) {
+       case SIOCSHWTSTAMP: /* set */
+               if (copy_from_user(&hwts_cfg, ifr->ifr_data, sizeof(hwts_cfg)))
+                       return -EFAULT;
+               if (hwts_cfg.tx_type == HWTSTAMP_TX_OFF &&
+                   hwts_cfg.rx_filter == HWTSTAMP_FILTER_ALL)
+                       return 0;
+               return -ERANGE;
+
+       case SIOCGHWTSTAMP: /* get */
+               hwts_cfg.tx_type = HWTSTAMP_TX_OFF;
+               hwts_cfg.rx_filter = HWTSTAMP_FILTER_ALL;
+               if (copy_to_user(ifr->ifr_data, &hwts_cfg, sizeof(hwts_cfg)))
+                       return -EFAULT;
+               return 0;
+
+       default:
+               return -EOPNOTSUPP;
+       }
+}
+
 static const struct net_device_ops peak_canfd_netdev_ops = {
        .ndo_open = peak_canfd_open,
        .ndo_stop = peak_canfd_close,
+       .ndo_eth_ioctl = peak_eth_ioctl,
        .ndo_start_xmit = peak_canfd_start_xmit,
        .ndo_change_mtu = can_change_mtu,
 };
 
+static int peak_get_ts_info(struct net_device *dev,
+                           struct ethtool_ts_info *info)
+{
+       info->so_timestamping =
+               SOF_TIMESTAMPING_TX_SOFTWARE |
+               SOF_TIMESTAMPING_RX_SOFTWARE |
+               SOF_TIMESTAMPING_SOFTWARE |
+               SOF_TIMESTAMPING_RX_HARDWARE |
+               SOF_TIMESTAMPING_RAW_HARDWARE;
+       info->phc_index = -1;
+       info->tx_types = BIT(HWTSTAMP_TX_OFF);
+       info->rx_filters = BIT(HWTSTAMP_FILTER_ALL);
+
+       return 0;
+}
+
+static const struct ethtool_ops peak_canfd_ethtool_ops = {
+       .get_ts_info = peak_get_ts_info,
+};
+
 struct net_device *alloc_peak_canfd_dev(int sizeof_priv, int index,
                                        int echo_skb_max)
 {
@@ -789,6 +836,7 @@ struct net_device *alloc_peak_canfd_dev(int sizeof_priv, int index,
 
        ndev->flags |= IFF_ECHO;
        ndev->netdev_ops = &peak_canfd_netdev_ops;
+       ndev->ethtool_ops = &peak_canfd_ethtool_ops;
        ndev->dev_id = index;
 
        return ndev;