Hi Xingyu, I am trying to establish some clarity about what to do here. The trusted firmware review has now been accepted https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3405. I could try to add your mentioned extra operation indexes to the ATF watchdog, to try to establish a standard ATF smc watchdog interface. Hypothetically then your linux driver could connect to any of the ATF watchdogs, apart from the meson indirection layer. I do not quite understand the meson layer to be honest, would we run the meson layer on non-amlogic SOCs? It looks feasible to strip the meson part from your driver so that it works on more socs, please correct me if I am wrong. Alternatively we could also add these extra operation indexes to this linux driver. Unfortunately I would not have a way to test that. Thanks Evan On Tue, Feb 25, 2020 at 6:43 PM Xingyu Chen <xingyu.chen@xxxxxxxxxxx> wrote: > > 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 > > .
