Skeleton power control machine configuration

[Xo Wang]

On Thu, Sep 22, 2016 at 10:26 PM, Joel Stanley <joel at jms.id.au> wrote:
> Hey Xo,
>
> On Fri, Sep 23, 2016 at 10:28 AM, Xo Wang <xow at google.com> wrote:
>> Hi folks,
>>
>> I was adding power sequencing and buttons for our P9 machine and I
>> noticed that Firestone, Garrison, and Witherspoon had patches to
>> op-pwrctl that replaced the net names on the power pins, added more
>> reset complexes, etc.
>>
>> https://github.com/openbmc/openbmc/blob/master/meta-openbmc-machines/meta-openpower/meta-ibm/meta-witherspoon/recipes-phosphor/skeleton/skeleton/0001-Set-witherspoon-power-pin-and-pgood-nets.patch
>> https://github.com/openbmc/openbmc/blob/ced4c34ee252d0036b714425eecb0ed8bb528750/meta-openbmc-machines/meta-openpower/meta-ibm/meta-garrison/recipes-phosphor/skeleton/skeleton/0001-Add-power-control-support-for-the-Garrison-system.patch
>>
>> I didn't want to do the same for our machine. I propose moving machine
>> specific options to the Python configuration so we can eliminate the
>> skeleton patches.
>
> Great! This was an area of concern for me as well.
>
> I'm not sure what the future plans are for this part of the codebase.
> I think that fixing it to remove the out of tree patches and enable
> new machines is great for the time being. We should check with Patrick
> and Brad as to their plans for the future, so we don't waste time on
> code that will be reworked.
>

This looked like the shortest path to per-machine power config until
we designed something new, so I just went and implemented it. I
thought Patrick did mention rewriting but you're right, we need this
part to work pretty soon.

>>
>> I mailed my prototype to the Gerrit that adds a dbus call to
>> system_manager, C bindings, and power control logic to handle the
>> abstraction. Please take a look.
>>
>> https://gerrit.openbmc-project.xyz/#/c/605/
>> https://gerrit.openbmc-project.xyz/#/c/606/
>> https://gerrit.openbmc-project.xyz/#/c/607/
>> https://gerrit.openbmc-project.xyz/#/c/608/
>>
>> I'm planning to also extend the GPIO/net name abstraction to reset and
>> power buttons, since they're also using net names directly in their
>> sources.
>
> I had a brief look at the patches and they look good to me. I left
> some minor comments in gerrit.
>
> In the future we want to ensure that all of the GPIOs are configured
> correctly to a known state at BMC boot.

To add to that, we might want to experiment with reset tolerance
registers to protect systems against blips from unexpected BMC warm
resets.

>
> Cheers,
>
> Joel

cheers
xo