Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753073AbcJJPio (ORCPT ); Mon, 10 Oct 2016 11:38:44 -0400 Received: from mail-oi0-f65.google.com ([209.85.218.65]:36813 "EHLO mail-oi0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752586AbcJJPim (ORCPT ); Mon, 10 Oct 2016 11:38:42 -0400 Date: Mon, 10 Oct 2016 10:20:55 -0500 From: Rob Herring To: Schrempf Frieder Cc: "dmitry.torokhov@gmail.com" , "pawel.moll@arm.com" , "ijc+devicetree@hellion.org.uk" , "galak@codeaurora.org" , "luis@debethencourt.com" , "linux-input@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v2 2/3] input: pwm-beeper: add documentation for volume devicetree bindings Message-ID: <20161010152055.GA6868@rob-hp-laptop> References: <1475831223-6006-1-git-send-email-frieder.schrempf@exceet.de> <1475831223-6006-3-git-send-email-frieder.schrempf@exceet.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1475831223-6006-3-git-send-email-frieder.schrempf@exceet.de> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1859 Lines: 48 On Fri, Oct 07, 2016 at 09:08:17AM +0000, Schrempf Frieder wrote: > This patch adds the documentation for the devicetree bindings to set > the volume levels. > > Signed-off-by: Frieder Schrempf > --- > Changes in v2: > - split into 3 separate patches > - make volume properties optional > > .../devicetree/bindings/input/pwm-beeper.txt | 22 ++++++++++++++++++++++ > 1 file changed, 22 insertions(+) > > diff --git a/Documentation/devicetree/bindings/input/pwm-beeper.txt b/Documentation/devicetree/bindings/input/pwm-beeper.txt > index be332ae..6d8ba4e 100644 > --- a/Documentation/devicetree/bindings/input/pwm-beeper.txt > +++ b/Documentation/devicetree/bindings/input/pwm-beeper.txt > @@ -5,3 +5,25 @@ Registers a PWM device as beeper. > Required properties: > - compatible: should be "pwm-beeper" > - pwms: phandle to the physical PWM device > + > +Optional properties: > +- volume-levels: Array of distinct volume levels. These need to be in the > + range of 0 to 500, while 0 means 0% duty cycle (mute) and 500 means > + 50% duty cycle (max volume). > + Please note that the actual volume of most beepers is highly > + non-linear, which means that low volume levels are probably somewhere > + in the range of 1 to 30 (0.1-3% duty cycle). What does the index correspond to? The linear volume? > +- default-volume-level: the default volume level (index into the > + array defined by the "volume-levels" property) > + > +The volume level can be set via sysfs under /sys/class/input/inputX/volume. > +The maximum volume level index can be read from /sys/class/input/inputX/max_volume_level. > + > +Example: > + > + pwm-beeper { > + compatible = "pwm-beeper"; > + pwms = <&pwm4 0 5000>; > + volume-levels = <0 8 20 40 500>; > + default-volume-level = <4>; > + }; > -- > 1.9.1