Re: [PATCH v3 04/15] ACPI: Document ACPI device specific properties

Arnd Bergmann
2014-10-04T10:59:59Z

On Saturday 04 October 2014 02:13:23 Rafael J. Wysocki wrote:
> > Because people get the format wrong regardless of documentation. The
> > format:
> >
> > Package () {
> > Package () { ^ref1, data, data },
> > Package () { ^ref2, data },
> > Package () { ^ref3, data, data, data },
> > }
> >
> > Is superior to the format:
> >
> > Package () { ^ref1, data, data, ^ref2, data, ^ref3, data, data, data }
> >
> > Because in the former you have delimiters that can be used to verify
> > each tuple. Imagine someone misses a data element for one of these
> > tuples. In the former layout you can detect this easily while in the
> > latter you cannot.
>
> I agree with this particular thing (although other people seem to have
> problems with too many package nesting levels) but I'm not sure what that
> has to do with the example given above (let me quote again):
>
> > Putting everything to a single package results this:
> >
> > Package () { "pwms", Package () {"led-red", ^PWM0, 0, 10, "led-green", ^PWM0, 1, 10 }}
> >
> > But I think the below looks better:
> >
> > Package () { "pwms", Package () {^PWM0, 0, 10, ^PWM0, 1, 10 }}
> > Package () { "pwm-names", Package () {"led-red", "led-green"}}
> >
> > and it is trivial to match with the corresponding DT fragment.
>
> that I was commenting. Both cases contains the
>
> Package () { ^ref1, data, data, ^ref2, data, ^ref3, data, data, data }
>
> format that you don't like, don't they?
>

There are two independent issues:

a) avoiding the need for "pwm-names" by embedding the name in the
"pwms" property

b) avoiding the need for "#pwm-cells" by having explicit separators between
entries in a "pwms" property.

It would be possible to do one but not the other.

Arnd
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