From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jean-Jacques Hiblot Subject: Re: [PATCH 2/2] dt-bindings: leds: document new "power-supply" property Date: Thu, 25 Jul 2019 13:08:46 +0200 Message-ID: <753b2c8d-e8fc-ec6e-f372-a84d4452fd33@ti.com> References: <20190708103547.23528-1-jjhiblot@ti.com> <20190708103547.23528-3-jjhiblot@ti.com> <20190724164757.GA3723@bogus> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20190724164757.GA3723@bogus> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Rob Herring Cc: jacek.anaszewski@gmail.com, pavel@ucw.cz, mark.rutland@arm.com, daniel.thompson@linaro.org, dmurphy@ti.com, linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org List-Id: devicetree@vger.kernel.org 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 >> --- >> 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. > >> + >> - 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 >>