From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Lechner Subject: Re: [PATCH 3/3] Input: pwm-beeper: add optional enable gpio Date: Fri, 6 Jan 2017 11:45:15 -0600 Message-ID: <79167ff5-64c2-c753-6341-beef32d3bb54@lechnology.com> References: <1483670635-25060-1-git-send-email-david@lechnology.com> <1483670635-25060-4-git-send-email-david@lechnology.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-input-owner@vger.kernel.org To: Andy Shevchenko Cc: Dmitry Torokhov , Rob Herring , Mark Rutland , linux-input , devicetree , "linux-kernel@vger.kernel.org" List-Id: devicetree@vger.kernel.org On 01/06/2017 11:28 AM, Andy Shevchenko wrote: > On Fri, Jan 6, 2017 at 4:43 AM, David Lechner wrote: >> This adds an optional enable gpio to the pwm-beeper device. This gpio is >> used in cases where the beeper needs to be switched on before using it. > > Isn't it a property of pin muxing? You may want to turn if off when not making a sound to save power. > >> For >> example, there may be an amplifier that is not always powered on. > > This looks like GPIO based fixed voltage regulator. Yes, I think a regulator could work here just as well. > >> >> Tested on LEGO MINDSTORMS EV3, which has a speaker connected to PWM through >> an amplifier. The amplifier has an enable pin that is connected to a gpio. >