Re: [RFC PATCH v2 0/7] of: Introduce hardware prober driver

[Doug Anderson]

Hi,

On Thu, Nov 9, 2023 at 2:06 AM Chen-Yu Tsai <wenst@xxxxxxxxxxxx> wrote:
>
> The driver as
> implemented currently doesn't deal with regulators or GPIO pins,
> since in the existing device trees they are either always on for
> regulators, or have GPIO hogs or pinmux and pinconfig directly
> tied to the pin controller.

I guess I won't object too much about this limitation for v1, but IMO
it would be good to get this sorted out since I think part of the
power of having the HW Prober is specifically that it can handle this
type of use case. You have a little bit of board-specific code that
knows how to turn on the regulators / GPIOs and can then probe the
devices.

Note: even if this is "board specific", it doesn't mean you couldn't
share code between boards. For instance, you could have a helper
function that would turn on regulators/GPIOs based on some type of
table and that helper function could be used across a whole pile of
Chromebooks. If a Chromebook is sufficiently different that it
couldn't use the helper function then it could call its own function,
but presumably it wouldn't be hard to support a bunch of boards
without much code.

As part of this, I think that your main "HW Prober" for Chromebooks
should be in "drivers/platform/chrome/". I think that the only things
that should be in the "drivers/of" directory should be helper
functions used by the Chromebook HW Probers.


-Doug