[PATCH v2 00/10] can: netlink: add CAN XL

[Vincent Mailhol <mailhol@kernel.org>]

Following all the refactoring on the CAN netlink done in series [1],
[2] and [3], this is now time to finally introduce the CAN XL netlink
interface.

Similarly to how CAN FD reuses the bittiming logic of Classical CAN,
CAN XL also reuses the entirety of CAN FD features, and, on top of
that, adds new features which are specific to CAN XL.

Patch #1 is a small clean-up which makes can_calc_bittiming() use
NL_SET_ERR_MSG() instead of netdev_err().

Patch #2 adds a check in can_dev_dropped_skb() to drop CAN FD frames
when CAN FD is turned off.

Patch #3 adds CAN_CTRLMODE_RESTRICTED. Note that contrary to the other
CAN_CTRL_MODE_XL_* that are introduced in the later patches, this
control mode is not specific to CAN XL. The nuance is that because
this restricted mode was only added in ISO 11898-1:2024, it is made
mandatory for CAN XL devices but optional for other protocols. This is
why this patch is added as a preparation before introducing the core
CAN XL logic.

Patch #4 adds all the CAN XL features which are inherited from CAN FD:
the nominal bittiming, the data bittiming and the TDC.

Patch #5 and #6 add two new CAN control modes which are specific to
CAN XL: CAN_CTRLMODE_XL_TMS, CAN_CTRLMODE_XL_ERR_SIGNAL respectively.

Finally, patch #7 to #10 add the PWM logic.

[1] can: netlink: preparation before introduction of CAN XL
Link: https://lore.kernel.org/linux-can/20241112165118.586613-7-mailhol.vincent@wanadoo.fr/

[2] can: rework the CAN MTU logic (CAN XL preparation step 2/3)
Link: https://lore.kernel.org/linux-can/20250923-can-fix-mtu-v3-0-581bde113f52@kernel.org/

[3] can: netlink: preparation before introduction of CAN XL step 3/3
Link: https://lore.kernel.org/linux-can/20250923-canxl-netlink-prep-v4-0-e720d28f66fe@kernel.org/

---
Changes in v2:

  - Add a new patch #1.

  - In patch #9, add a return statement to can_calc_tdco() when
    CONFIG_CAN_CALC_BITTIMING is not set. This fixes a warning as
    reported by the kernel test robot:

      Link: https://lore.kernel.org/linux-can/202510140553.qo3f0I9s-lkp@intel.com/

    While at it, add an error message.

Link to v1: https://lore.kernel.org/r/20251013-canxl-netlink-v1-0-f422b7e2729f@kernel.org

Changes in v1:

   - Add PWM

   - Add the CAN_CTRLMODE_RESTRICTED, CAN_CTRLMODE_XL_TMS and
     CAN_CTRLMODE_XL_ERR_SIGNAL control modes.

   - A lot has changed since the original RFC was sent in November
     last year.  The preparation patches went in a separate series as
     explained in the cover letter, and what used to be a single patch
     to introduce CAN XL is now a full series. A few additional
     details are added to the individual patches, but overall I did
     not keep track of all the changes over the last year. You may as
     well consider this as a new series.
   
Link to RFC: https://lore.kernel.org/linux-can/20241110155902.72807-16-mailhol.vincent@wanadoo.fr/

---
Vincent Mailhol (10):
      can: bittiming: apply NL_SET_ERR_MSG() to can_calc_bittiming()
      can: dev: can_dev_dropped_skb: drop CAN FD skbs if FD is off
      can: netlink: add CAN_CTRLMODE_RESTRICTED
      can: netlink: add initial CAN XL support
      can: netlink: add CAN_CTRLMODE_XL_TMS flag
      can: netlink: add CAN_CTRLMODE_XL_ERR_SIGNAL
      can: bittiming: add PWM parameters
      can: bittiming: add PWM validation
      can: calc_bittiming: add PWM calculation
      can: netlink: add PWM netlink interface

 drivers/net/can/dev/bittiming.c      |  63 +++++++
 drivers/net/can/dev/calc_bittiming.c |  36 ++++
 drivers/net/can/dev/dev.c            |  20 +-
 drivers/net/can/dev/netlink.c        | 357 +++++++++++++++++++++++++++++++++--
 include/linux/can/bittiming.h        |  81 +++++++-
 include/linux/can/dev.h              |  49 +++--
 include/uapi/linux/can/netlink.h     |  35 ++++
 7 files changed, 599 insertions(+), 42 deletions(-)
---
base-commit: ffee675aceb9f44b0502a8bec912abb0c4f4af62
change-id: 20241229-canxl-netlink-bc640af10673

Best regards,
-- 
Vincent Mailhol <mailhol@kernel.org>