Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932244AbcKVJHR (ORCPT ); Tue, 22 Nov 2016 04:07:17 -0500 Received: from hqemgate14.nvidia.com ([216.228.121.143]:14617 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755057AbcKVJHN (ORCPT ); Tue, 22 Nov 2016 04:07:13 -0500 X-PGP-Universal: processed; by hqnvupgp07.nvidia.com on Mon, 21 Nov 2016 13:05:51 -0800 Message-ID: <583406CC.9080306@nvidia.com> Date: Tue, 22 Nov 2016 14:20:20 +0530 From: Laxman Dewangan User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: Rob Herring CC: , , , , "Douglas Anderson" , Aleksandr Frid Subject: Re: [PATCH V2 1/2] regulator: pwm: DT: Add ramp delay for exponential voltage transition References: <1479479756-10755-1-git-send-email-ldewangan@nvidia.com> <20161121161727.y6pvydowiyeyy7qs@rob-hp-laptop> In-Reply-To: <20161121161727.y6pvydowiyeyy7qs@rob-hp-laptop> X-Originating-IP: [10.19.65.30] X-ClientProxiedBy: BGMAIL104.nvidia.com (10.25.59.13) To bgmail102.nvidia.com (10.25.59.11) Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2767 Lines: 57 On Monday 21 November 2016 09:47 PM, Rob Herring wrote: > On Fri, Nov 18, 2016 at 08:05:55PM +0530, Laxman Dewangan wrote: >> Some PWM regulator has the exponential transition in voltage change as >> opposite to fixed slew-rate linear transition on other regulators. >> For such PWM regulators, add the property to tell that voltage change >> is exponential and having fixed delay for any level of change. >> >> Signed-off-by: Laxman Dewangan >> CC: Douglas Anderson >> CC: Aleksandr Frid >> >> --- >> This patch is continuation of discussion on patch >> regulator: pwm: Fix regulator ramp delay for continuous mode >> https://patchwork.kernel.org/patch/9216857/ >> where is it discussed to have separate property for PWM which has >> exponential voltage transition. >> >> Changes from V1: >> - Pass the flag to tell that voltage ramp is exponential instead of >> providing delay. >> --- >> .../devicetree/bindings/regulator/pwm-regulator.txt | 12 ++++++++++++ >> 1 file changed, 12 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/regulator/pwm-regulator.txt b/Documentation/devicetree/bindings/regulator/pwm-regulator.txt >> index 3aeba9f..2d9ef3a 100644 >> --- a/Documentation/devicetree/bindings/regulator/pwm-regulator.txt >> +++ b/Documentation/devicetree/bindings/regulator/pwm-regulator.txt >> @@ -54,6 +54,18 @@ Optional properties: >> -------------------- >> - enable-gpios: GPIO to use to enable/disable the regulator >> >> +- voltage-ramp-exponential: Boolean, Some of PWM regulator has the exponential >> + transition in voltage ramp as opposite to fixed >> + slew-rate linear transition on other regulators. >> + For such PWM regulator, presence of this property will >> + tell that value of the regulator ramp delay provided by >> + DT property "regulator-ramp-delay" is exponential and >> + fixed delay for any voltage level change. >> + If PWM regulator supports the fixed linear slew rate >> + then this property should be absent from DT node and >> + property "regulator-ramp-delay" is used as linear slew >> + rate. > Sorry, but on further thought, I don't think we should mix different > units for the same property. Also, the fact that the ramp is exponential > is irrelevant. You just want an absolute delay time rather than a rate, > right? So instead, how about just "regulator-ramp-time-us". Roughly what > you had in v1, but not PWM specific. Can we say "regulator-settling-time-us" and make it generic i.e. part of the regulator core instead of PWM regulator specific? So no change for "regulator-ramp-delay". new property "regulator-settling-time-us" for fixed settling time in any voltage level change.