From 9be05c7f372940a2308e0301c5bdddab3022a449 Mon Sep 17 00:00:00 2001 From: Oliver Hartkopp Date: Fri, 17 Jun 2016 15:35:28 +0200 Subject: can: bcm: add documentation for CAN FD support Signed-off-by: Oliver Hartkopp Signed-off-by: Marc Kleine-Budde --- Documentation/networking/can.txt | 25 ++++++++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) (limited to 'Documentation/networking') diff --git a/Documentation/networking/can.txt b/Documentation/networking/can.txt index d58ff8467953..aa15b9ee2e70 100644 --- a/Documentation/networking/can.txt +++ b/Documentation/networking/can.txt @@ -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) -- cgit v1.2.3