Re: [PATCH v4 0/7] typec: tcpm: Add sink side support for PPS

From: Heikki Krogerus
Date: Tue Jan 30 2018 - 08:25:15 EST


On Tue, Jan 02, 2018 at 03:50:48PM +0000, Adam Thomson wrote:
> This patch set adds sink side support for the PPS feature introduced in the
> USB PD 3.0 specification.
>
> The source PPS supply is represented using the Power Supply framework to provide
> access and control APIs for dealing with it's operating voltage and current,
> and switching between a standard PDO and PPS APDO operation. During standard PDO
> operation the voltage and current is read-only, but for APDO PPS these are
> writable as well to allow for control.
>
> It should be noted that the keepalive for PPS is not handled within TCPM. The
> expectation is that the external user will be required to ensure re-requests
> occur regularly to ensure PPS remains and the source does not hard reset.

Sorry for the late reply. I don't have any major problems with these
other than with 6/7. The documentation should be for the psy class,
not tcpm. I'm also not comfortable with the "select POWER_SUPPLY", but
if Guenter does not think it's a problem, I'm fine with it. I guess we
can always, for example, introduce stubs for the power_supply*
functions, and drop the dependency later.

But as usual with tcpm.c, Guenter needs to give his ACK.

Oh yes, and Sebastian needs to ACK the power_supply changes or course.


Thanks,

--
heikki