From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lucas Stach Subject: Re: [PATCH 2/4] cpufreq: add i.MX5 cpufreq driver Date: Mon, 26 May 2014 17:28:35 +0200 Message-ID: <1401118115.4829.60.camel@weser.hi.pengutronix.de> References: <1401099308-9658-1-git-send-email-l.stach@pengutronix.de> <1401099308-9658-2-git-send-email-l.stach@pengutronix.de> <1401101131.4829.29.camel@weser.hi.pengutronix.de> <1401107748.4829.39.camel@weser.hi.pengutronix.de> <1401109863.4829.46.camel@weser.hi.pengutronix.de> <1401112697.4829.56.camel@weser.hi.pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Viresh Kumar Cc: Mark Rutland , "devicetree@vger.kernel.org" , Pawel Moll , "linux-pm@vger.kernel.org" , Ian Campbell , "Rafael J. Wysocki" , Rob Herring , "linux-arm-kernel@lists.infradead.org" , Sascha Hauer , Kumar Gala , Shawn Guo List-Id: devicetree@vger.kernel.org Am Montag, den 26.05.2014, 20:52 +0530 schrieb Viresh Kumar: > On 26 May 2014 19:28, Lucas Stach wrote: > > Right, the OPP in my example define the minimum required voltage for > > each frequency. This is in accordance to the OPP binding. But for this > > chip the datasheet explicitly says that it is ok to power the cpu rail > > with up to 1.4V, regardless of the current operating frequency. So this > > 1.4V is really the upper bound I would like to pass to the regulator > > framework. This ensures that the driver still works properly even if the > > external regulator can't scale down to the minimum (or in other words > > optimal) voltage. > > One more query. You have mentioned earlier and I just wanted to confirm > this. In your platform/board regulator only supports one voltage, i.e. 1.4 uV, > and it we can't get lower values out of regulator ? > > If that's the case, why are you looking to use regulator at all? The platform I'm working on supports cpu rail voltage regulation just fine. I just want to make sure that the driver works properly on platforms where this isn't the case. As the datasheet explicitly allows this case I want to make sure to not introduce a software only restriction, where there isn't any in hardware. Regards, Lucas -- Pengutronix e.K. | Lucas Stach | Industrial Linux Solutions | http://www.pengutronix.de/ |