Hi Linus,

On Fri, Nov 24, 2017 at 10:30:40AM +0100, Linus Walleij wrote:

The goal I'm working toward is to rid the kernel of the global
GPIO numberspace.

This means GPIO lines should be references by the local offset
on the GPIO chip.

This patch set starts to move gpio_keys toward using GPIO
look-up tables instead of global GPIO numbers to find their
GPIOs.

As an example I did (I think) the necessary patches to
convert DaVinci and i.MX to use this. There are several users
also x86 platform devices.

Strategy:

- Merge the patch to input/keyboard/gpio_keys* to support
  using descriptors from board files.

- Refactor the whole universe to get proper names on GPIO
  chips, and reference the GPIO lines with local offsets using
  tables, as in the example patches in this series. These
  can trickle in after the first patch is merged in Input.
  The work to be done can be seen if you type:
  git grep gpio_keys_platform_data

- When all are refactored, remove the "gpio" and "active low"
  members from the platform data and delete the associated
  legacy GPIO handling in the input driver for gpio_keys.

Posting this with the examples to get buy-in from Dmitry
before I go and spend time refactoring the world.

I think this is a worthy goal, but I wonder if we could get static GPIO
descriptors work with fwnode_get_named_gpiod() so we could retire the
platform data parsing altogether. We'd need to extend static device
properties to have notion of children though.

Thanks.

-- 
Dmitry