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)

Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

1 files changed, 20 insertions, 7 deletions

diff --git a/drivers/net/can/vcan.c b/drivers/net/can/vcan.c
index ea2d94285936..4f93c0be0053 100644
--- a/drivers/net/can/vcan.c
+++ b/drivers/net/can/vcan.c
@@ -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;