Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753864Ab3IJEo2 (ORCPT ); Tue, 10 Sep 2013 00:44:28 -0400 Received: from mail.active-venture.com ([67.228.131.205]:57650 "EHLO mail.active-venture.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752848Ab3IJEo1 (ORCPT ); Tue, 10 Sep 2013 00:44:27 -0400 X-Originating-IP: 108.223.40.66 Message-ID: <522EA3A8.7040508@roeck-us.net> Date: Mon, 09 Sep 2013 21:44:24 -0700 From: Guenter Roeck User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130803 Thunderbird/17.0.8 MIME-Version: 1.0 To: Stephen Warren CC: Wei Ni , Mark Brown , "khali@linux-fr.org" , "lm-sensors@lm-sensors.org" , "linux-tegra@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v3 1/2] hwmon: (lm90) Add power control References: <1378722552-10357-1-git-send-email-wni@nvidia.com> <1378722552-10357-2-git-send-email-wni@nvidia.com> <20130909111242.GW29403@sirena.org.uk> <522DB253.6000707@roeck-us.net> <20130909135022.GZ29403@sirena.org.uk> <20130909155043.GA18975@roeck-us.net> <522E9059.3070305@nvidia.com> <522E93D6.2010304@roeck-us.net> <522E94AE.7000804@wwwdotorg.org> <522E97CE.4070300@roeck-us.net> <522E9C84.9070405@wwwdotorg.org> In-Reply-To: <522E9C84.9070405@wwwdotorg.org> 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: 1535 Lines: 39 On 09/09/2013 09:13 PM, Stephen Warren wrote: > On 09/09/2013 09:53 PM, Guenter Roeck wrote: >> On 09/09/2013 08:40 PM, Stephen Warren wrote: >>> On 09/09/2013 09:36 PM, Guenter Roeck wrote: > ... >>>> My understanding is that by adding regulator support you essentially >>>> committed to adding regulators (if necessary dummy ones) for this driver >>>> to all those platforms. This is quite similar to other drivers in the >>>> same situation. Once you start along that route, you'll have to go it >>>> all the way. >>> >>> By using regulator_get_optional(), the regulator should be optional, >>> hence you only have to add it to platforms that need it. >>> >> >> Earlier comments suggest that this is not the intended use case for >> regulator_get_optional(). > > Isn't the issue only whether the optional aspect of the regulator is > implemented by: > > a) regulator_get_optional() returning failure, then the driver having to > check for that and either using or not-using the regulator. > > b) regulator_get_optional() returning a dummy regulator automatically > when none is specified in DT or the regulator lookup table, and hence > the driver can always call regulator_enable/disable on the returned value. > I don't know. The regulator folks would have to answer that. Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/