Hi Douglas,

On Wed, Jun 07, 2023 at 02:49:22PM -0700, Douglas Anderson wrote:

The big motivation for this patch series is mostly described in the patch
("drm/panel: Add a way for other devices to follow panel state"), but to
quickly summarize here: for touchscreens that are connected to a panel we
need the ability to power sequence the two device together. This is not a
new need, but so far we've managed to get by through a combination of
inefficiency, added costs, or perhaps just a little bit of brokenness.
It's time to do better. This patch series allows us to do better.

Assuming that people think this patch series looks OK, we'll have to
figure out the right way to land it. The panel patches and i2c-hid
patches will go through very different trees and so either we'll need
an Ack from one side or the other or someone to create a tag for the
other tree to pull in. This will _probably_ require the true drm-misc
maintainers to get involved, not a lowly committer. ;-)

Version 2 of this patch series doesn't change too much. At a high level:
* I added all the forgotten "static" to functions.
* I've hopefully made the bindings better.
* I've integrated into fw_devlink.
* I cleaned up a few descriptions / comments.

This still needs someone to say that the idea looks OK or to suggest
an alternative that solves the problems. ;-)

Thanks for working on this.

I haven't seen in any of your commit messages how the panels were
actually "packaged" together?

Do a panel model typically come together with the i2c-hid support, or is
it added at manufacture time?

If it's the latter, it's indeed a fairly loose connection and we need
your work.

If it's the former though and we don't expect a given panel reference to
always (or never) come with a touchscreen attached, I guess we can have
something much simpler with a bunch of helpers that would register a
i2c-hid device and would be called by the panel driver itself.

And then, since everything is self-contained managing the power state
becomes easier as well.

Maxime