Most flexcan IP cores support 2 RX modes:
- FIFO
- mailbox
The flexcan IP core on the MCF5441X cannot receive CAN RTR messages
via mailboxes. However the mailbox mode is more performant. The commit
| 1c45f5778a ("can: flexcan: add ethtool support to change rx-rtr setting during runtime")
added support to switch from FIFO to mailbox mode on these cores.
After testing the mailbox mode on the MCF5441X by Angelo Dureghello,
this patch marks it (without RTR capability) as supported. Further the
IP core overview table is updated, that RTR reception via mailboxes is
not supported.
Link: https://lore.kernel.org/all/20220121084425.3141218-1-mkl@pengutronix.de
Tested-by: Angelo Dureghello <angelo@kernel-space.org>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch adds ethtool support to get the number of message buffers
configured for reception/transmission, which may also depends on
runtime configurations such as the 'rx-rtr' flag state.
Link: https://lore.kernel.org/all/20220108181633.420433-1-dario.binacchi@amarulasolutions.com
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
[mkl: port to net-next/master, replace __sw_hweight64 by simpler calculation]
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This patch adds a private flag to the flexcan driver to switch the
"rx-rtr" setting on and off.
"rx-rtr" on - Receive RTR frames. (default)
The CAN controller can and will receive RTR frames.
On some IP cores the controller cannot receive RTR
frames in the more performant "RX mailbox" mode and
will use "RX FIFO" mode instead.
"rx-rtr" off - Waive ability to receive RTR frames. (not supported on all IP cores)
This mode activates the "RX mailbox mode" for better
performance, on some IP cores RTR frames cannot be
received anymore.
The "RX FIFO" mode uses a FIFO with a depth of 6 CAN frames.
The "RX mailbox" mode uses up to 62 mailboxes.
Link: https://lore.kernel.org/all/20220107193105.1699523-6-mkl@pengutronix.de
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Co-developed-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Most flexcan IP cores support 2 RX modes:
- FIFO
- mailbox
Some IP core versions cannot receive CAN RTR messages via mailboxes.
This patch adds quirks to document this.
This information will be used in a later patch to switch from FIFO to
more performant mailbox mode at the expense of losing the ability to
receive RTR messages. This trade off is beneficial in certain use
cases.
Link: https://lore.kernel.org/all/20220107193105.1699523-5-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Most flexcan IP cores support 2 RX modes:
- FIFO
- mailbox
The names for these modes were chosen to reflect the name of the
rx-offload mode they are using.
The name of the RX modes should better reflect their difference with
regards the flexcan IP core. So this patch renames the various
occurrences of OFF_FIFO to RX_FIFO and OFF_TIMESTAMP to RX_MAILBOX:
| FLEXCAN_TX_MB_RESERVED_OFF_FIFO -> FLEXCAN_TX_MB_RESERVED_RX_FIFO
| FLEXCAN_TX_MB_RESERVED_OFF_TIMESTAMP -> FLEXCAN_TX_MB_RESERVED_RX_MAILBOX
| FLEXCAN_QUIRK_USE_OFF_TIMESTAMP -> FLEXCAN_QUIRK_USE_RX_MAILBOX
Link: https://lore.kernel.org/all/20220107193105.1699523-4-mkl@pengutronix.de
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
This is a preparation patch for the upcoming support to change the
rx-rtr capability via the ethtool API.
Link: https://lore.kernel.org/all/20220107193105.1699523-3-mkl@pengutronix.de
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
