Re: [PATCH] powernv: Add OCC driver to mmap sensor area

From: Benjamin Herrenschmidt
Date: Mon Oct 02 2017 - 04:35:23 EST


On Mon, 2017-10-02 at 14:14 +1100, Stewart Smith wrote:
> Shilpasri G Bhat <shilpa.bhat@xxxxxxxxxxxxxxxxxx> writes:
> > This driver provides interface to mmap the OCC sensor area
> > to userspace to parse and read OCC inband sensors.
>
> Why?
>
> Is this for debug? If so, the existing exports interface should be used.
>
> If there's actual sensors, we already have two ways of exposing sensors
> to Linux: the OPAL_SENSOR API and the IMC API.
>
> Why this method and not use the existing ones?

More than that, a sensor should be exposed to userspace via hwmon, not
some random direct userspace map.

Ben.