Hi, Julius
On 2020/2/25 9:23, Julius Werner wrote:
The SMC function ID may be solved by the DTS, but the wdt indexs(Eg:
SMCWD_INFO) are also different
for each vendor. The imx_sc_wdt.c is also use the SMC to operate the
WDT, but the wdt indexs(Eg: IMX_SIP_TIMER_START_WDOG)
are different from ours. IMO, If the ATF can implement a common hal
interface and index for watchdog, then writing a
common smc wdt driver will be easier to compatible with all vendors.
The MediaTek driver is still in flux (e.g. still being reviewed in
Trusted Firmware here:
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3405),
we can still change it. So if we can now decide on making this a
"standard" driver, we can change the MediaTek interface to match IMX
and standardize on that. (There are existing Chromebooks shipped with
a different interface, but we could handle those separately with
downstream patches. I think having a unified interface that will
prevent this problem in the future would be worth some extra
complication right now.)
If the ATF provides a common watchdog hal interface and index, I am
happy to match
the generic sec wdt driver. Compared to the current MTK wdt index [0],
the following
indexes need to be supported for meson wdt [1].
- *_INIT.
- *_GETTIMEOUT.
- *_RESETNOW. It is used to reset the system right now, similar to your
SOFT RESET.
For another platform-specific parameter "SMC function ID", the generic
sec wdt driver can get it from the dts, but if
the driver want to compatible with more vendors in the future, maybe we
should consider Guenter's suggestion at [2]
[0]: https://patchwork.kernel.org/patch/11395579/
[1]: https://patchwork.kernel.org/patch/11331271/
[2]:
https://lore.kernel.org/linux-watchdog/20200220155159.GB29658@xxxxxxxxxxxx/T/#md00328548222965054cd19ec7dda074f8fc09fe2
Best Regards
.
