On Wed, Feb 19, 2020 at 03:04:54PM -0800, Julius Werner wrote: > > You are not the first 'watchdog in firmware accessed via an SMC call'. > > Is there some more detail about what implementation this is? Part of > > TF-A? Defined by some spec (I can dream)? > > This is just some random implementation written by me because we > needed one. I would like it to be the new generic implementation, but > it sounds like people here prefer the naming to be MediaTek specific > (at least for now). The other SMC watchdog we're aware of is > imx_sc_wdt but unfortunately that seems to hardcode platform-specific There is one more pending, for Meson SMC. https://patchwork.kernel.org/project/linux-watchdog/list/?series=227733 Unfortunately it uses Meson firmware API functions, though it has pretty much the same functionality since those ultimately end up calling arm_smccc_smc(). Guenter > details in the interface (at least in the pretimeout SMC) so we can't > just expand that. With this driver I tried to directly wrap the kernel > watchdog interface so it should be platform-agnostic and possible to > expand this driver to other platforms later if desired. The SMC > function ID would still always have to be platform-specific, > unfortunately (but we could pass it in through the device tree), since > the Arm SMC spec doesn't really leave any room for OS-generic SMCs > like this.
