vcan: add CAN FD support

- move the length calculation from dlc to real length (using canfd_frame)
- allow to switch the driver between CAN and CAN FD (change of MTU)

---
 drivers/net/can/vcan.c |   27 ++++++++++++++++++++-------
 1 file changed, 20 insertions(+), 7 deletions(-)

index ea2d942..4f93c0b 100644
@@ -70,13 +70,12 @@ MODULE_PARM_DESC(echo, "Echo sent frames (for testing). Default: 0 (Off)");
  static void vcan_rx(struct sk_buff *skb, struct net_device *dev)
 {
-	struct can_frame *cf = (struct can_frame *)skb->data;
+	struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
 	struct net_device_stats *stats = &dev->stats;
  	stats->rx_packets++;
-	stats->rx_bytes += cf->can_dlc;
+	stats->rx_bytes += cfd->len;
 -	skb->protocol  = htons(ETH_P_CAN);
 	skb->pkt_type  = PACKET_BROADCAST;
 	skb->dev       = dev;
 	skb->ip_summed = CHECKSUM_UNNECESSARY;

@@ -86,7 +85,7 @@ static void vcan_rx(struct sk_buff *skb, struct net_device *dev)
  static netdev_tx_t vcan_tx(struct sk_buff *skb, struct net_device *dev)
 {
-	struct can_frame *cf = (struct can_frame *)skb->data;
+	struct canfd_frame *cfd = (struct canfd_frame *)skb->data;
 	struct net_device_stats *stats = &dev->stats;
 	int loop;
 @@ -94,7 +93,7 @@ static netdev_tx_t vcan_tx(struct sk_buff *skb, struct net_device *dev)
 		return NETDEV_TX_OK;

stats->tx_packets++;
- stats->tx_bytes += cf->can_dlc;
+ stats->tx_bytes += cfd->len;
/* set flag whether this packet has to be looped back */
loop = skb->pkt_type == PACKET_LOOPBACK;
@@ -108,7 +107,7 @@ static netdev_tx_t vcan_tx(struct sk_buff *skb, struct net_device *dev)
* CAN core already did the echo for us
*/
stats->rx_packets++;
- stats->rx_bytes += cf->can_dlc;
+ stats->rx_bytes += cfd->len;
}
kfree_skb(skb);
return NETDEV_TX_OK;
@@ -133,14 +132,28 @@ static netdev_tx_t vcan_tx(struct sk_buff *skb, struct net_device *dev)
return NETDEV_TX_OK;
}
+static int vcan_change_mtu(struct net_device *dev, int new_mtu)
+{
+ /* Do not allow changing the MTU while running */
+ if (dev->flags & IFF_UP)
+ return -EBUSY;
+
+ if (new_mtu != CAN_MTU && new_mtu != CANFD_MTU)
+ return -EINVAL;
+
+ dev->mtu = new_mtu;
+ return 0;
+}
+
static const struct net_device_ops vcan_netdev_ops = {
.ndo_start_xmit = vcan_tx,
+ .ndo_change_mtu = vcan_change_mtu,
};
static void vcan_setup(struct net_device *dev)
{
dev->type = ARPHRD_CAN;
- dev->mtu = sizeof(struct can_frame);
+ dev->mtu = CAN_MTU;
dev->hard_header_len = 0;
dev->addr_len = 0;
dev->tx_queue_len = 0;

1.7.10.4