On 02.10.14 00:39, Scott Wood wrote: > On Wed, 2014-10-01 at 15:27 +0200, Alexander Graf wrote: >> The generic Linux framework to power off the machine is a function pointer >> called pm_power_off. The trick about this pointer is that device drivers can >> potentially implement it rather than board files. >> >> Today on PowerPC we set pm_power_off to invoke our generic full machine power >> off logic which then calls ppc_md.power_off to invoke machine specific power >> off. >> >> However, when we want to add a power off GPIO via the "gpio-poweroff" driver, >> this card house falls apart. That driver only registers itself if >> pm_power_off >> is NULL to ensure it doesn't override board specific logic. However, since we >> always set pm_power_off to the generic power off logic (which will just not >> power off the machine if no ppc_md.power_off call is implemented), we can't >> implement power off via the generic GPIO power off driver. >> >> To fix this up, let's get rid of the ppc_md.power_off logic and just always >> use >> pm_power_off as was intended. Then individual drivers such as the GPIO power >> off >> driver can implement power off logic via that function pointer. >> >> With this patch set applied and a few patches on top of QEMU that implement a >> power off GPIO on the virt e500 machine, I can successfully turn off my >> virtual >> machine after halt. > > Are there any plans to handle restart similarly?
I don't see an immediate need for it, as we do have access to reset via the guts device. I also don't see any generic driver in Linux that would implement reset via a gpio controller device, so apparently it's not incredibly common to implement reset via gpio. Alex _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
