can: flexcan: remove the auto stop mode for IMX93

IMX93 A0 chip involve the internal q-channel handshake in LPCG and
CCM to automatically handle the Flex-CAN IPG STOP signal. Only after
FLEX-CAN enter stop mode then can support the self-wakeup feature.
But meet issue when do the continue system PM stress test. When config
the CAN as wakeup source, the first time after system suspend, any data
on CAN bus can wakeup the system, this is as expect. But the second time
when system suspend, data on CAN bus can't wakeup the system. If continue
this test, we find in odd time system enter suspend, CAN can wakeup the
system, but in even number system enter suspend, CAN can't wakeup the
system. IC find a bug in the auto stop mode logic, and can't fix it easily.
So for the new imx93 A1, IC drop the auto stop mode and involve the
GPR to support stop mode (used before). IC define a bit in GPR which can
trigger the IPG STOP signal to Flex-CAN, let it go into stop mode.
And NXP claim to drop IMX93 A0, and only support IMX93 A1. So this patch
remove the auto stop mode, and add flag FLEXCAN_QUIRK_SETUP_STOP_MODE_GPR
to imx93.

Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Link: https://lore.kernel.org/all/20230726112458.3524165-2-haibo.chen@nxp.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: flexcan: add auto stop mode for IMX93 to support wakeup

IMX93 do not contain a GPR to config the stop mode, it will set
the flexcan into stop mode automatically once the ARM core go
into low power mode (WFI instruct) and gate off the flexcan
related clock automatically. But to let these logic work as
expect, before ARM core go into low power mode, need to make
sure the flexcan related clock keep on.

To support stop mode and wakeup feature on imx93, this patch
add a new fsl_imx93_devtype_data to separate from imx8mp.

Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Link: https://lore.kernel.org/all/1669116752-4260-1-git-send-email-haibo.chen@nxp.com
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: flexcan: fix typo: FLEXCAN_QUIRK_SUPPPORT_* -> FLEXCAN_QUIRK_SUPPORT_*

Fix typo "FLEXCAN_QUIRK_SUPPPORT_*" -> "FLEXCAN_QUIRK_SUPPORT_".

Link: https://lore.kernel.org/all/20220811093617.1861938-3-mkl@pengutronix.de
Fixes: f04aefd4659b ("can: flexcan: mark RX via mailboxes as supported on MCF5441X")
Fixes: c5c88591040e ("can: flexcan: add more quirks to describe RX path capabilities")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: flexcan: export flexcan_ethtool_ops and remove flexcan_set_ethtool_ops()

The function flexcan_set_ethtool_ops() does one thing: populate
net_device::ethtool_ops. Instead, it is possible to directly assign
this field and remove one function call and slightly reduce the object
size. To do so, export flexcan_ethtool_ops so it becomes visible to
flexcan-core.c.

Signed-off-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://lore.kernel.org/all/20220727104939.279022-4-mailhol.vincent@wanadoo.fr
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

can: flexcan: mark RX via mailboxes as supported on MCF5441X

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

| 1c45f5778a3b ("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>

can: flexcan: add ethtool support to change rx-rtr setting during runtime

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>