diff options
| author | Oliver Hartkopp <socketcan@hartkopp.net> | 2017-04-11 15:43:43 +0200 |
|---|---|---|
| committer | Marc Kleine-Budde <mkl@pengutronix.de> | 2021-05-27 09:42:21 +0200 |
| commit | 02546884221279da2725e87e35348290470363d7 (patch) | |
| tree | 51c10f14227c19228ad727b55840392669a2b8ae /include | |
| parent | 7e97d274db920df479e222fed10e7b242f90ffb0 (diff) | |
can: uapi: introduce CANFD_FDF flag for mixed content in struct canfd_frame
The struct can_frame and struct canfd_frame intentionally share the
same layout to be able to write CAN frame content into a CAN FD frame
structure. When this is done the former differentiation via CAN_MTU /
CANFD_MTU is lost. CANFD_FDF allows programmers to mark CAN FD frames
in the case of using struct canfd_frame for mixed CAN/CAN FD
content (dual use).
N.B. the Kernel APIs do NOT provide mixed CAN / CAN FD content inside
of struct canfd_frame therefore the CANFD_FDF flag is disregarded by
Linux.
Link: https://lore.kernel.org/r/20170411134343.3089-1-socketcan@hartkopp.net
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'include')
| -rw-r--r-- | include/uapi/linux/can.h | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/include/uapi/linux/can.h b/include/uapi/linux/can.h index ac5d7a31671f..90801ada2bbe 100644 --- a/include/uapi/linux/can.h +++ b/include/uapi/linux/can.h @@ -135,9 +135,18 @@ struct can_frame { * controller only the CANFD_BRS bit is relevant for real CAN controllers when * building a CAN FD frame for transmission. Setting the CANFD_ESI bit can make * sense for virtual CAN interfaces to test applications with echoed frames. + * + * The struct can_frame and struct canfd_frame intentionally share the same + * layout to be able to write CAN frame content into a CAN FD frame structure. + * When this is done the former differentiation via CAN_MTU / CANFD_MTU gets + * lost. CANFD_FDF allows programmers to mark CAN FD frames in the case of + * using struct canfd_frame for mixed CAN / CAN FD content (dual use). + * N.B. the Kernel APIs do NOT provide mixed CAN / CAN FD content inside of + * struct canfd_frame therefore the CANFD_FDF flag is disregarded by Linux. */ #define CANFD_BRS 0x01 /* bit rate switch (second bitrate for payload data) */ #define CANFD_ESI 0x02 /* error state indicator of the transmitting node */ +#define CANFD_FDF 0x04 /* mark CAN FD for dual use of struct canfd_frame */ /** * struct canfd_frame - CAN flexible data rate frame structure |