Re: [PATCH] gpio: mockup: use device properties instead of platform_data

[Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>]

On Tue, Sep 25, 2018 at 10:53:30AM +0200, Linus Walleij wrote:
> On Mon, Sep 24, 2018 at 9:35 AM Bartosz Golaszewski <brgl@xxxxxxxx> wrote:
> > niedz., 23 wrz 2018 o 13:17 Bartosz Golaszewski <brgl@xxxxxxxx> napisał(a):
> > >
> > > Some users want to introduce device tree support to the mockup driver.
> > > Let's make it easier by switching to using generic device properties.
> > > The driver stays compatible with previous use cases and after this
> > > conversion there'll be no need to change the way probing of mockup
> > > GPIO chips works.
> > >
> > > Tested with libgpiod test suite.
> > >
> > > Signed-off-by: Bartosz Golaszewski <brgl@xxxxxxxx>
> (...)
> > Linus, I just noticed that we either need to drop the check for
> > -ENOENT or add an else that returns on any other error. I'll need to
> > send a v2
> 
> OK business as usual.
> 
> > but I'll let you first tell me if you like the general idea.
> 
> I don't know, I'm a bit ignorant about the idea, scope and
> ambition with device properties.
> 
> In my book this relates to the fwnode concept, but maybe
> I'm wrong?

I think you are right.

> Mika, please fill us in here. The device properties in gpiolib
> came in the patch
> "gpio: Rework of_gpiochip_set_names() to use device property accessors"

I'm not sure what to answer to be honest :) The idea behind that patch
was that we would be able to use the same properties (DT properties,
ACPI _DSD properties, or possibly built-in properties) to set names for
GPIOs.