From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH v3 1/2] hwmon: (lm90) Add power control Date: Mon, 09 Sep 2013 22:13:56 -0600 Message-ID: <522E9C84.9070405@wwwdotorg.org> 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> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <522E97CE.4070300-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Guenter Roeck Cc: Wei Ni , Mark Brown , "khali-PUYAD+kWke1g9hUCZPvPmw@public.gmane.org" , "lm-sensors-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org" , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-tegra@vger.kernel.org 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.