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Commit 9be05c7f authored by Oliver Hartkopp's avatar Oliver Hartkopp Committed by Marc Kleine-Budde
Browse files

can: bcm: add documentation for CAN FD support 



Signed-off-by: default avatarOliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: default avatarMarc Kleine-Budde <mkl@pengutronix.de>
parent 6f3b911d

Documentation/networking/can.txt

+24 −1
Original line number Diff line number Diff line
@@ -31,6 +31,7 @@ This file contains 
      4.2.4 Broadcast Manager message sequence transmission

      4.2.5 Broadcast Manager receive filter timers

      4.2.6 Broadcast Manager multiplex message receive filter

      4.2.7 Broadcast Manager CAN FD support

    4.3 connected transport protocols (SOCK_SEQPACKET)

    4.4 unconnected transport protocols (SOCK_DGRAM)
@@ -799,7 +800,7 @@ solution for a couple of reasons: 
    } mytxmsg;



    (..)

    mytxmsg.nframes = 4;

    mytxmsg.msg_head.nframes = 4;

    (..)



    write(s, &mytxmsg, sizeof(mytxmsg));
@@ -852,6 +853,28 @@ solution for a couple of reasons: 


    write(s, &msg, sizeof(msg));



  4.2.7 Broadcast Manager CAN FD support



  The programming API of the CAN_BCM depends on struct can_frame which is

  given as array directly behind the bcm_msg_head structure. To follow this

  schema for the CAN FD frames a new flag 'CAN_FD_FRAME' in the bcm_msg_head

  flags indicates that the concatenated CAN frame structures behind the

  bcm_msg_head are defined as struct canfd_frame.



    struct {

            struct bcm_msg_head msg_head;

            struct canfd_frame frame[5];

    } msg;



    msg.msg_head.opcode  = RX_SETUP;

    msg.msg_head.can_id  = 0x42;

    msg.msg_head.flags   = CAN_FD_FRAME;

    msg.msg_head.nframes = 5;

    (..)



  When using CAN FD frames for multiplex filtering the MUX mask is still

  expected in the first 64 bit of the struct canfd_frame data section.



  4.3 connected transport protocols (SOCK_SEQPACKET)

  4.4 unconnected transport protocols (SOCK_DGRAM)