On Thu, Jul 25, 2019 at 01:08:46PM +0200, Jean-Jacques Hiblot wrote: > Hi Rob, > > On 24/07/2019 18:47, Rob Herring wrote: > > On Mon, Jul 08, 2019 at 12:35:47PM +0200, Jean-Jacques Hiblot wrote: > > > Most of the LEDs are powered by a voltage/current regulator. describing in > > > the device-tree makes it possible for the LED core to enable/disable it > > > when needed. > > > > > > Signed-off-by: Jean-Jacques Hiblot <[email protected]> > > > --- > > > Documentation/devicetree/bindings/leds/common.txt | 5 +++++ > > > 1 file changed, 5 insertions(+) > > > > > > diff --git a/Documentation/devicetree/bindings/leds/common.txt > > > b/Documentation/devicetree/bindings/leds/common.txt > > > index 70876ac11367..e093a2b7eb90 100644 > > > --- a/Documentation/devicetree/bindings/leds/common.txt > > > +++ b/Documentation/devicetree/bindings/leds/common.txt > > > @@ -61,6 +61,11 @@ Optional properties for child nodes: > > > - panic-indicator : This property specifies that the LED should be used, > > > if at all possible, as a panic indicator. > > > +- power-supply : A voltage/current regulator used to to power the LED. > > > When a > > > + LED is turned off, the LED core disable its regulator. The > > > + same regulator can power many LED (or other) devices. It is > > > + turned off only when all of its users disabled it. > > Not sure this should be common. It wouldn't apply to cases where we have > > an LED controller parent nor gpio and pwm LEDs and those are most cases. > > It does make sense for GPIO and PWM bindings if the anode of LED is tied to > a regulated voltage and the cathod to the control line. > > The same is true for a certain class of true LED controller that do not > deliver power but act like current sinks. > > JJ > > > > > Perhaps what makes sense here is an regulator-led binding.
You didn't comment on this alternative... and I confess I'm not quite sure what Rob means by a regulator-led binding so I can't really comment either. Rob, is there any analogous example for a regulator-<something-else> binding to compare with? Daniel. > > > > > + > > > - trigger-sources : List of devices which should be used as a source > > > triggering > > > this LED activity. Some LEDs can be related to a > > > specific > > > device and should somehow indicate its state. E.g. > > > USB 2.0 > > > -- > > > 2.17.1 > > >
