On Tue, Feb 20, 2018 at 1:19 PM, Baruch Siach [off-list ref] wrote:

From: Dave Stevenson <redacted>

Pi3 and Compute Module 3 have a GPIO expander that the
VPU communicates with.
There is a mailbox service that now allows control of this
expander, so add a kernel driver that can make use of it.

Reviewed-by: Stefan Wahren <redacted>
Signed-off-by: Dave Stevenson <redacted>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
---
v5:
  * Use the parent node to find the firmware

This v5 version applied to the GPIO tree for v4.17.

Yours,
Linus Walleij