Merge patch series "can: at91: add can_state_get_by_berr_counter() helper, cleanup...

Marc Kleine-Budde <mkl@pengutronix.de> says:

This series first introduces the can_state_get_by_berr_counter()
helper function. It returns the current TX and RX state depending on
the provided CAN bit error counters. It will be later used by the
at91_can driver.

The remaining patches of this series first clean up the at91_can
driver, clean up the bus- and line error (including bus-off) handling,
and then convert it use the rx_offload helper. The driver works better
under high system load and the order of received CAN frames is better
maintained.

Due to a hardware limitation the converted driver could trigger a race
condition in the can_restart() CAN bus-off handler. The patch series
[1] fixes the issue.

[1] https://lore.kernel.org/all/20231005-can-dev-fix-can-restart-v2-0-91b5c1fd922c@pengutronix.de

Changes in v2:
- 1/27: can_state_err_to_state(): use symbolic error values instead of
  plain numbers (Thanks Vincent)
- 27/27: fix patch description and typos (Thanks Vincent)
- Link to v1: https://lore.kernel.org/all/20231004-at91_can-rx_offload-v1-0-c32bf99097db@pengutronix.de

Link: https://lore.kernel.org/all/20231005-at91_can-rx_offload-v2-0-9987d53600e0@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>