On 15/12/16 15:34, Peter Rosin wrote:

On 2016-12-15 15:04, Jon Hunter wrote:

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On 15/12/16 12:04, Peter Rosin wrote:

...

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                              The only other option is to add another
property called something like 'ti,ac-detect-override-pol' to specify
the polarity you want.

How is that helping? It's no different that just saying active-low for
boards that do not invert ACOK (which is what I currently do in my dts,
but I hate doing it since it doesn't match dt docs and is therefore just
wrong).

By providing a means for the user to specify the polarity for their
board. Of course the documentation would need to be updated as well. I
think all solutions will be ugly if we need to preserve compatibility.

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To be honest, I am not sure how this type of thing is normally handled.
So probably best to put together a patch with whatever option you feel
best and explain why this is needed and see what the dev-tree folks say.

I suspect that at the end of the day documentation is less important than
regressions. But if there are more than one implementation of the same
spec and Linux is not following it, it's kind of harsh to change the spec
to match Linux. I doubt that there are any other users in this case though,
but what do I know?

I'll send a patch re-documenting ti,ac-detect-gpios to specify AC absence
instead of AC presence, let's see what the dt people thinks...

Fine with me and of course that works for Tegra, but how does that
ultimately help you? How do you tell the driver to use active-high
instead of the default which is not active-low?

Oh, you didn't know that gpiod_set_value/gpiod_get_value takes care of
active high/low automatically. That explains the disconnect.

Ah I see. Yes I see that now in the gpiod_get_value().

Thanks!
Jon

-- 
nvpublic