A growing number of CAN controllers do not have support for individual RX
hardware filters based on the Remote Transmission Request (RTR) bit. This
leads to various work-arounds on the driver level mixing hardware and
software filtering.
As the use of RTR frames is discouraged by CAN in Automation (CiA) - and
not even supported by newer standards, e.g. CAN FD - this often leads to
unnecessary overhead, added complexity, and worst-case to non-portable
behavior between various CAN controller drivers.
Instead, move to a simpler approach where the ability to accept/reject RTR
frames is globally configured via Kconfig. By default, all incoming RTR
frames are rejected at the driver level, a setting which can be supported
in hardware by most in-tree CAN controllers drivers.
Legacy applications or protocol implementations, where RTR reception is
required, can now select CONFIG_CAN_ACCEPT_RTR to accept incoming RTR
frames matching added CAN filters. These applications or protocols will
need to distinguish between RTR and data frames in their respective CAN RX
frame handling routines.
Signed-off-by: Henrik Brix Andersen <hebad@vestas.com>
Remove the CAN_FILTER_FDF flag for filtering on classic CAN/CAN FD frames
as it is not supported natively by any known CAN controller.
Applications can still filter on classic CAN/CAN FD frames in their receive
callback functions as needed.
Fixes: #64554
Signed-off-by: Henrik Brix Andersen <hebad@vestas.com>
Unify spelling of CAN Flexible Data-rate abbreviation to "CAN FD" instead
of "CAN-FD". The former aligns with the CAN in Automation (CiA)
recommendation.
Signed-off-by: Henrik Brix Andersen <hebad@vestas.com>
Move the test definitions, frames, and filters to common.h/common.c and
reuse them between the classic CAN and CAN-FD API tests.
Signed-off-by: Henrik Brix Andersen <hebad@vestas.com>
