From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vladimir Zapolskiy Date: Sat, 07 Jan 2017 23:32:00 +0000 Subject: Re: [PATCH 0/4] video: ARM CLCD: add support of an optional GPIO to enable panel Message-Id: <252ad888-fa9d-695a-58ed-46806e4374fd@mleia.com> List-Id: References: <20161221032717.13154-1-vz@mleia.com> <20170102142228.GI14217@n2100.armlinux.org.uk> In-Reply-To: <20170102142228.GI14217@n2100.armlinux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org On 01/02/2017 04:22 PM, Russell King - ARM Linux wrote: > On Fri, Dec 30, 2016 at 09:23:59AM +0100, Linus Walleij wrote: >> On Wed, Dec 21, 2016 at 4:27 AM, Vladimir Zapolskiy wrote: >> >>> The changeset contains a number of cleanups, changed semantics of >>> init_panel() callback, which allows to simplify getting of panel >>> properties from panel device tree node, and a handling of optional >>> "enable-gpios" panel property, the latter is described in >>> display/panel/panel-dpi.txt device tree binding documentation, but >>> it has been unsupported by the ARM CLCD driver. >>> >>> Vladimir Zapolskiy (4): >>> video: ARM CLCD: sort included headers out alphabetically >>> video: ARM CLCD: use panel device node for panel initialization >>> video: ARM CLCD: use panel device node for getting backlight and mode >>> video: ARM CLCD: add support of an optional GPIO to enable panel >> >> As you may have seen Tomi has stepped down as FBDEV maintainer and >> this subsystem is now orphaned. >> >> I guess Andrew Morton merges patches for it in this case, he usually does. >> >> But what we should actually do is create a new DRM driver for CLCD >> in drivers/gpu/drm/arm/clcd* >> >> It's maybe not a small undertaking :( >> >> But in case you're interested in the job, I will pitch in and test the result >> on all ARM reference designs plus Nomadik. > > A DRM driver for it would probably be a good idea, but dealing with all > the weird and wonderful connection arrangements may not be that easy... > Linus, Russell, I've immediately encountered a problem while porting the driver to DRM, because LPC18xx/LPC43xx SoCs are powered by Cortex-M3/M4 cores and DRM framework has build and runtime dependencies on MMU. That said, in short term I would expect a continuation of support for the legacy CLCD framebuffer driver, which works fine on MMU-less SoCs. -- With best wishes, Vladimir