On Wed, May 31, 2023 at 08:18:14AM +0200, Alexander Stein wrote: > Hi, > > Am Dienstag, 30. Mai 2023, 17:19:45 CEST schrieb Uwe Kleine-König: > > For active low lines the semantic of output-low and output-high is hard > > to grasp because there is a double negation involved and so output-low > > is actually a request to drive the line high (aka inactive). > > > > So introduce output-inactive and output-active with the same semantic as > > output-low and output-high respectively have today, but with a more > > sensible name. > > > > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx> > > --- > > Documentation/devicetree/bindings/gpio/gpio.txt | 16 +++++++++++----- > > 1 file changed, 11 insertions(+), 5 deletions(-) > > > > diff --git a/Documentation/devicetree/bindings/gpio/gpio.txt > > b/Documentation/devicetree/bindings/gpio/gpio.txt index > > d82c32217fff..2f037bbd3ffa 100644 > > --- a/Documentation/devicetree/bindings/gpio/gpio.txt > > +++ b/Documentation/devicetree/bindings/gpio/gpio.txt > > @@ -209,15 +209,21 @@ Required properties: > > - gpios: Store the GPIO information (id, flags, ...) for each GPIO to > > affect. Shall contain an integer multiple of the number of > cells > > specified in its parent node (GPIO controller node). > > + > > Only one of the following properties scanned in the order shown below. > > This means that when multiple properties are present they will be searched > > in the order presented below and the first match is taken as the intended > > configuration. > > -- input: A property specifying to set the GPIO direction as input. > > -- output-low A property specifying to set the GPIO direction as output > > with - the value low. > > -- output-high A property specifying to set the GPIO direction as output > > with - the value high. > > +- input: A property specifying to set the GPIO direction as > > input. +- output-inactive: A property specifying to set the GPIO > > direction as output + with the inactive value > (depending on the > > line's polarity, + which is active-high by default) > > +- output-active: A property specifying to set the GPIO direction as > > output + with the active value. > > I know this is essentially just renaming currently existing properties. > But these mutual exclusive (boolean) properties make it impossible to change > them in DT overlay. Any ideas how to support changing the output level onGPIO > hogs in DT overlay? The universal way to address this would be to make it possible in dtbos to delete properties (and nodes). Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-König | Industrial Linux Solutions | https://www.pengutronix.de/ |
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