From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756228Ab2APTdO (ORCPT ); Mon, 16 Jan 2012 14:33:14 -0500 Received: from opensource.wolfsonmicro.com ([80.75.67.52]:59132 "EHLO opensource.wolfsonmicro.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755630Ab2APTdM (ORCPT ); Mon, 16 Jan 2012 14:33:12 -0500 Date: Mon, 16 Jan 2012 19:33:09 +0000 From: Mark Brown To: Thomas Abraham Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, rpurdie@rpsys.net, linux-samsung-soc@vger.kernel.org, grant.likely@secretlab.ca, rob.herring@calxeda.com, kgene.kim@samsung.com, jg1.han@samsung.com, kyungmin.park@samsung.com, cbou@mail.ru, kwangwoo.lee@gmail.com, augulis.darius@gmail.com, ben-linux@fluff.org, lars@metafoo.de, patches@linaro.org Subject: Re: [PATCH v2 1/2] backlight: lcd: add driver for raster-type lcd's with gpio controlled panel reset Message-ID: <20120116193309.GG3514@opensource.wolfsonmicro.com> References: <1326354211-27064-1-git-send-email-thomas.abraham@linaro.org> <1326354211-27064-2-git-send-email-thomas.abraham@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1326354211-27064-2-git-send-email-thomas.abraham@linaro.org> X-Cookie: You will contract a rare disease. User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 12, 2012 at 01:13:30PM +0530, Thomas Abraham wrote: > + /* set regulator voltage if specified */ > + if (pd->min_uV || pd->max_uV) > + if (regulator_set_voltage(lp->regulator, > + pd->min_uV, pd->max_uV)) > + dev_info(lp->dev, > + "voltage set failed\n"); > + if (regulator_enable(lp->regulator)) > + dev_info(lp->dev, "regulator enable failed\n"); You should really pay more attention to the errors here, especially for the enable - this function does return an error code so you could usefully tell the caller about failures. > + /* > + * If power to lcd and/or lcd interface is controlled using a regulator, > + * get the handle to the regulator for later use during power switching. > + */ > + lp->regulator = regulator_get(dev, "vcc-lcd"); > + if (IS_ERR(lp->regulator)) > + dev_info(dev, "could not find regulator\n"); It's much better style to assume that there will be a regulator in the code and let the core worry about stubbing it out. Given that you don't offer any support for varying the voltage dynamically I'd suggest just removing the set_voltage() support for now - if someone adds it they can always add additional properties and worry about handling that situation then.