Re: [PATCHv7][ 2/2] video: backlight: gpio-backlight: Add DT support.

[Alexander Shiyan]

> On Thu, Dec 05, 2013 at 06:55:09PM +0100, Denis Carikli wrote:
> [...]
> > +Optional properties:
> > +  - default-state: The initial state of the backlight.
> > +    Valid values are "on", "off", and "keep".
> > +    The "keep" setting will keep the backlight at whatever its current
> > +    state is, without producing a glitch. The default is keep if this
> > +    property is not present.
> 
> I'm not sure if "on", "off" and "keep" are a good choice for this
> binding. Having strings for these tristate values seems suboptimal.
> Other bindings have chosen a representation that, transposed to this
> use-case, would read something like this:
> 
> 	- default-state: The initial state of the backlight. Valid
> 	  values:
> 	  - 0: off
> 	  - 1: on
> 
> 	If the "default-state" property is not present, the default
> 	will be to keep the current backlight state.
> 
> Which is in fact the exact behaviour that your binding describes, but
> it's much more intuitive in my opinion.

Why we cannot use GPIO bindings for active level here?
What a reason for "keep" state? Can this be an additional property?

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