From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthias Kaehlcke Subject: Re: [PATCH v1] regulator: Add driver for voltage controlled regulators Date: Mon, 27 Feb 2017 10:53:10 -0800 Message-ID: <20170227185310.GA153648@google.com> References: <20170210204348.107871-1-mka@chromium.org> <20170222002214.sejshtotyiobn6n2@rob-hp-laptop> <20170225031919.GB56005@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Content-Disposition: inline In-Reply-To: <20170225031919.GB56005-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Rob Herring Cc: Liam Girdwood , Mark Brown , Mark Rutland , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Douglas Anderson , Brian Norris , Guenter Roeck , Dmitry Torokhov List-Id: devicetree@vger.kernel.org El Fri, Feb 24, 2017 at 07:19:19PM -0800 Matthias Kaehlcke ha dit: > El Tue, Feb 21, 2017 at 06:22:14PM -0600 Rob Herring ha dit: > > > > > +Optional properties: > > > +-------------------- > > > ... > > > +- min-slew-down-rate : Describes how slowly the regulator voltage will decay > > > + down in the worst case (lightest expected load). > > > + Specified in uV / us (like main regulator ramp rate). > > > + This value is required when ovp-threshold-percent is > > > + specified. > > > > Don't we have a standard prop for this or that's just for ramp? > > regulator-ramp-delay is related, but not exactly the same. The > ramp-delay is applied at the end of an up- or downward transition, > while this prop only specifies the downward rate and is applied in > between partial transitions towards the final voltage. > > We possibly could use ramp-delay and add a set_voltage_time() op to > vctrl to prevent the core code from adding the "normal" ramp-delay at > the end of the transition. However it could be confusing that vctrl > handles the ramp-delay differently than other drivers, especially we > don't want a delay in the upward transition for vctrl. But maybe > nobody would care about the different behavior, as long as the > regulator does its job ... Actually the behavior of a delay on the downward transition and no delay on the upward transition is hardware specific. Other users of this driver might need a standard ramp delay, therefore I think it's not a good idea to (re-)use this property in vctrl. Matthias -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html