Documentation/networking/can.rst

31 receive raw CAN frames, directly to/from the controller hardware.
32 Queueing of frames and higher-level transport protocols like ISO-TP
45 network layer as a network device, so that CAN frames from the
54 frames on different or the same CAN IDs.  Several sockets listening on
55 the same interface for frames with the same CAN ID are all passed the
56 same received matching CAN frames.  An application wishing to
60 CAN-IDs, frames, etc.
93   CAN frames between them, (sophisticated) queueing of CAN frames, and
142 Local Loopback of Sent Frames
160 some kind of local loopback of the sent CAN frames on the appropriate
164 transmission and reception of media dependent frames. Due to the
191 arbitration problems and error frames caused by the different
195 Frames that can optionally be passed to the user application in the
196 same way as other CAN frames. Whenever an error on the physical layer
198 creates an appropriate error message frame. Error messages frames can
289 be 0 (zero). In this case the socket receives CAN frames from every
295 Reading CAN frames from a bound CAN_RAW socket (see above) consists
317 Writing CAN frames can be done similarly, with the write(2) system call::
340 To write CAN frames on sockets bound to 'any' CAN interface the
373 switches the socket into a mode that allows the handling of CAN FD frames
374 and (legacy) CAN frames simultaneously (see :ref:`socketcan-rawfd`).
425 - The socket only receives valid data frames (=> no error message frames)
426 - The loopback of sent CAN frames is enabled (see :ref:`socketcan-local-loopback2`)
427 - The socket does not receive its own sent frames (in loopback mode)
439 The reception of CAN frames using CAN_RAW sockets can be controlled
474 To disable the reception of CAN frames on the selected CAN_RAW socket:
481 data causes the raw socket to discard the received CAN frames. But
509 both SFF frames with CAN ID 0x123 and EFF frames with 0xXXXXX123 can pass.
530 called Error Message Frames that can optionally be passed to the user
531 application in the same way as other CAN frames. The possible
563 When the local loopback is enabled, all the sent CAN frames are
565 frames' CAN-ID on this given interface to meet the multi user
566 needs. The reception of the CAN frames on the same socket that was
589 Once CAN_RAW_FD_FRAMES is enabled the application can send both CAN frames
590 and CAN FD frames. OTOH the application has to handle CAN and CAN FD frames
629 CANFD_MTU sized CAN FD frames.
636 socket option returns an error: No problem. You'll get legacy CAN frames
637 or CAN FD frames and can process them the same way.
640 CAN FD frames by checking if the device maximum transfer unit is CANFD_MTU.
653 frames are passed to user space that matched *all* given CAN filters. The
672 	CAN driver supports the echo of frames on driver level, see
687 Periodic transmission tasks of CAN frames or a sequence of CAN frames can be
691 A BCM socket is not intended for sending individual CAN frames using the
696 message header with a command ('opcode') followed by zero or more CAN frames.
708             struct can_frame frames[0];
711 The aligned payload 'frames' uses the same basic CAN frame structure defined
822 	subsequent frame in frames. This is intended as usage simplification. For
827 	Filter by can_id alone, no frames required (nframes=0).
843 	Send reply for RTR-request (placed in op->frames[0]).
860 Up to 256 CAN frames can be transmitted in a sequence in the case of a cyclic
861 TX task configuration. The number of CAN frames is provided in the 'nframes'
862 element of the BCM message head. The defined number of CAN frames are added
867     /* create a struct to set up a sequence of four CAN frames */
879 With every transmission the index in the array of CAN frames is increased
904 than one CAN frames can be passed in a RX_SETUP configuration message. The
906 have to match in the subsequent CAN frames with the received CAN frame.
907 If one of the subsequent CAN frames is matching the bits in that frame data
909 Up to 257 CAN frames (multiplex filter bit mask CAN frame plus 256 CAN
940 schema for the CAN FD frames a new flag 'CAN_FD_FRAME' in the bcm_msg_head
957 When using CAN FD frames for multiplex filtering the MUX mask is still
989   (e.g. current/maximum frames per second) this 1 second timer is
1001 lists to deliver received CAN frames to CAN protocol modules. These
1020     rcvlist_err - list for error message frames masks
1027     stats       - SocketCAN core statistics (rx/tx frames, match ratios, ...)
1041 frames received by CAN interfaces and to send CAN frames::
1043     can_rx_register   - subscribe CAN frames from a specific interface
1044     can_rx_unregister - unsubscribe CAN frames from a specific interface
1084 Local Loopback of Sent Frames
1090 set to prevent the PF_CAN core from locally echoing sent frames
1126 frames without real CAN controller hardware. Virtual CAN network
1310 by monitoring CAN error message frames and do a restart when
1333 CAN frames anyway. The payload length to the bus-relevant DLC mapping is
1344 N.B. CAN FD capable devices can also handle and send legacy CAN frames.