From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ezequiel Garcia Subject: Re: [PATCH 8/8] drm/tilcdc: panel: Add support for enable GPIO Date: Fri, 11 Jul 2014 14:38:59 -0300 Message-ID: <20140711173859.GA869@arch.cereza> References: <1405088334-11215-1-git-send-email-ezequiel@vanguardiasur.com.ar> <1405088334-11215-9-git-send-email-ezequiel@vanguardiasur.com.ar> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Fabio Estevam Cc: Ezequiel Garcia , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Russell King , Daniel Vetter , DRI mailing list List-Id: devicetree@vger.kernel.org Hello Fabio, On 11 Jul 12:08 PM, Fabio Estevam wrote: > On Fri, Jul 11, 2014 at 11:18 AM, Ezequiel Garcia > wrote: > > In order to support the "enable GPIO" available in many panel devic= es, > > this commit adds a proper devicetree binding. > > > > By providing an enable GPIO in the devicetree, the driver can now t= urn > > off and on the panel device, and/or the backlight device. Both the > > backlight and the GPIO are optional properties. > > + panel_mod->enable_gpio =3D devm_gpiod_get(&pdev->dev, "enab= le"); > > + if (IS_ERR(panel_mod->enable_gpio)) { > > + ret =3D PTR_ERR(panel_mod->enable_gpio); > > + if (ret !=3D -ENOENT) { >=20 > Shouldn't this be controlled by a regulator instead? What if the pane= l > is powered from a PMIC output? I'm not sure I understand how is that related. I have a New Heaven LCD = panel (NHD-4.3-480272EF-ATXL#-T) and it has a signal called "Display On/Off" = that I'm using to enable and disable the panel from a GPIO. This is useful when switching the output from the panel to the HDMI for instance, and turn off the display panel when the output goes to the HD= MI. Probably I'm missing something, I can't really see how regulators fit h= ere. Thanks! --=20 Ezequiel Garc=EDa, Free Electrons Embedded Linux, Kernel and Android Engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe devicetree" i= n the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html