Re: Query about Open drain flag with active LOW

[Laxman Dewangan <ldewangan@nvidia.com>]

On Tuesday 28 March 2017 06:38 PM, Linus Walleij wrote:
> On Tue, Mar 28, 2017 at 11:03 AM, Laxman Dewangan <ldewangan@nvidia.com> wrote:
>
>
>
> I think it should be
>          if (of_flags & OF_GPIO_SINGLE_ENDED) {
>                  if (of_flags & OF_GPIO_ACTIVE_LOW)
>                          *flags |= GPIO_OPEN_SOURCE;
>                  else
>                          *flags |= GPIO_OPEN_DRAIN;
>          }
>
>
> Similar change is needed in the dtbinding gpio header also to invert the
> ACTIVE state with open drain/source.
> OK I think there are no real users of this feature yet, so it would be great if
> you could send a patch, especially if you also have hardware so you can test it.
>

Thinking more, active low/high for line is independent of the open 
drain/source behavior.
Per my understanding, Active low/high depends on the how external device 
provides signal or glue logic designed. Open drain/source is kind of 
setting pin state between GND or VDD or high impedance.

Let me send patch on decoupling the active HIGH/LOW with open 
drain/source and discuss more in the patch.


Thanks,
Laxman




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