From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sascha Hauer Date: Thu, 05 Jul 2012 06:20:11 +0000 Subject: Re: [PATCH] pwm-backlight: add regulator and GPIO support Message-Id: <20120705062011.GI30009@pengutronix.de> List-Id: References: <1340976167-27298-1-git-send-email-acourbot@nvidia.com> <20120704104840.GJ24458@pengutronix.de> <4FF43692.2040805@nvidia.com> <20120704130056.GC30009@pengutronix.de> <4FF45DDF.9000306@nvidia.com> <20120704152451.GA7333@sirena.org.uk> <4FF4FDC0.8020405@nvidia.com> In-Reply-To: <4FF4FDC0.8020405-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Alex Courbot Cc: Mark Brown , Thierry Reding , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-fbdev-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" On Thu, Jul 05, 2012 at 11:36:48AM +0900, Alex Courbot wrote: > On 07/05/2012 12:24 AM, Mark Brown wrote: > >On Thu, Jul 05, 2012 at 12:14:39AM +0900, Alex Courbot wrote: > >>On Wed 04 Jul 2012 10:00:56 PM JST, Sascha Hauer wrote: > > > >>>Also please be aware that using a regulator in the pwm backlight will > >>>instantly break all existing users. That's hardly your fault though. > > > >>Sorry, I don't see why. Could you elaborate on this? > > > >All existing machines will start failing during probe as they won't be > >able to find the regulator - you should ideally make sure everyone in > >mainline gets an appropriate regulator set up. > > Oh, that is a mistake of mine then. Driver probe should continue if > no regulator is declared (but should fail if some other error > occured). I want to maintain backward compatibility with current > users of the driver, so regulator/gpio specification should be > optional. I think the only way doing this is to add a flag to platform_data. I don't know if that's accepted though. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |