Hello Vincent!
Very impressive! Thanks for the effort.
Together with the example in the dummyxl driver it should become quite
easy to integrate the netlink API into my XCANB driver hack for testing.
Picking up the dummyxl driver I wonder if it would make sense to
mainline this driver probably as can_nltest driver?!?
Of course this driver should be disabled or combined with some kernel
testing Kconfig stuff. But is it a great testing tool.
From what I can see with the bitrate and tdc configurations the
extension for CAN XL is ok.
If you take a look at this manual
https://github.com/linux-can/can-doc/blob/master/x_can/xcan_user_manual_v350.pdf
on page 268/304 you will find the PWM configuration which consists of
three values with 6 bits each. I assume this to be similar in all CAN XL
controllers.
The PWM feature switches the physical layer for a CAN XL transceiver in
the CAN XL data phase. This is a weird feature to do some PWM on the
controllers' TX data pin to be able to switch the physical layer while
maintaining the CAN transceiver package with 8 pin layout.
Additionally to this PWM configuration register, the PWM CAN XL
transceiver switch feature has to be enabled similar to the way we
enable 'fd on' or 'xl on' today.
You can see this bit called XLTR in the Operating Mode section on page
269/304 and 270/304 .
E.g. that might be named 'xltrx [on|off]' (default off)
Best regards,
Oliver
On 10.11.24 16:55, Vincent Mailhol wrote:
Because of popular request [1] and to celebrate the fact that I joined
the kernel web of trust this week [2], here is an RFC to introduce the
CAN XL netlink support.
The logic is simple. The CAN XL basically just reuse the same kind of
parameters as CAN FD: the databittiming and the TDC. So the series is
just a bunch of refactor to either:
- factorize code.
- rename some variable to differentiate between CAN FD and XL.
- make some function more generic to accept both CAN FD and XL.
The feature is working™: there is a dummy driver at the end of the
series to show the traffic from the userland to a driver. This said, I
did close to zero testing. Once I had one CAN XL frame reaching the
driver, I call it a day, and decided to send the work. Regardless, it
is Sunday night. If I do not send it now, that would be next week-end.
Probably some mistakes are hidden here and there, but this should be
enough for an RFC level.
Also, I am not fully happy that can_dbt_changelink() requires 8
parameters. I will probably revisit this later on. But for the moment,
I think this is acceptable for an RFC.
Overall, I do not want to rush this series. Linus should send the rc7
anytime soon, and the merge window will probably start in eight days.
I do not think this series will be finalized by then. I still need to
give a deeper look at ISO 11898-1:2024 [3] to check that everything is
good. However, if I receive positive feedback on this RFC, I would
probably like to have the first patch merged so that I do not have to
rebase that tree wide patch each time someone makes a change.
I will send a second RFC series for iplink2 just after this one. Stay
tuned!
[1] https://lore.kernel.org/linux-can/CAEQ16vpxthctdrpv0kBKEZJA8VNYffjGGPBGBY93RmKDD49bAQ@xxxxxxxxxxxxxx/
[2] https://git.kernel.org/pub/scm/docs/kernel/pgpkeys.git/commit/?id=81d335d3586c
[3] https://www.iso.org/fr/standard/86384.html
Vincent Mailhol (14):
can: dev: add struct data_bittiming_params to group FD parameters
can: netlink: replace tabulation by space in assignement
can: bittiming: rename CAN_CTRLMODE_TDC_MASK into
CAN_CTRLMODE_FD_TDC_MASK
can: bittiming: rename can_tdc_is_enabled() into
can_fd_tdc_is_enabled()
can: netlink: can_changelink(): rename tdc_mask into
fd_tdc_flag_provided
can: netlink: make can_tdc_changelink() FD agnostic
can: netlink: add can_dtb_changelink()
can: netlink: add can_validate_tdc()
can: netlink: make can_tdc_get_size() FD agnostic
can: netlink: make can_tdc_fill_info() FD agnostic
can: netlink: document which symbols are FD specific
can: netlink: add CAN XL support
can: netlink: add userland error messages
!!! DO NOT MERGE !!! can: add dummyxl driver
drivers/net/can/Kconfig | 8 +
drivers/net/can/Makefile | 1 +
drivers/net/can/ctucanfd/ctucanfd_base.c | 8 +-
drivers/net/can/dev/calc_bittiming.c | 2 +-
drivers/net/can/dev/dev.c | 12 +-
drivers/net/can/dev/netlink.c | 422 ++++++++++++------
drivers/net/can/dummyxl.c | 224 ++++++++++
drivers/net/can/flexcan/flexcan-core.c | 4 +-
drivers/net/can/ifi_canfd/ifi_canfd.c | 10 +-
drivers/net/can/kvaser_pciefd.c | 6 +-
drivers/net/can/m_can/m_can.c | 8 +-
drivers/net/can/peak_canfd/peak_canfd.c | 6 +-
drivers/net/can/rcar/rcar_canfd.c | 4 +-
.../net/can/rockchip/rockchip_canfd-core.c | 4 +-
.../can/rockchip/rockchip_canfd-timestamp.c | 2 +-
.../net/can/spi/mcp251xfd/mcp251xfd-core.c | 4 +-
drivers/net/can/usb/esd_usb.c | 6 +-
drivers/net/can/usb/etas_es58x/es58x_core.c | 4 +-
drivers/net/can/usb/etas_es58x/es58x_fd.c | 8 +-
drivers/net/can/usb/gs_usb.c | 8 +-
drivers/net/can/usb/kvaser_usb/kvaser_usb.h | 2 +-
.../net/can/usb/kvaser_usb/kvaser_usb_core.c | 6 +-
drivers/net/can/usb/peak_usb/pcan_usb_core.c | 6 +-
drivers/net/can/xilinx_can.c | 6 +-
include/linux/can/bittiming.h | 4 +-
include/linux/can/dev.h | 39 +-
include/uapi/linux/can/netlink.h | 21 +-
27 files changed, 606 insertions(+), 229 deletions(-)
create mode 100644 drivers/net/can/dummyxl.c
