From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans Verkuil Date: Tue, 09 Oct 2012 11:00:24 +0000 Subject: Re: [PATCH 05/14] media: add a V4L2 OF parser Message-Id: <201210091300.24124.hverkuil@xs4all.nl> List-Id: References: <1348754853-28619-1-git-send-email-g.liakhovetski@gmx.de> <5073FDC8.8090909@samsung.com> In-Reply-To: <5073FDC8.8090909@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Sylwester Nawrocki Cc: Guennadi Liakhovetski , linux-media@vger.kernel.org, devicetree-discuss@lists.ozlabs.org, Laurent Pinchart , Magnus Damm , linux-sh@vger.kernel.org, Mark Brown , Stephen Warren , Arnd Bergmann , Grant Likely , Thomas Abraham , Tomasz Figa On Tue 9 October 2012 12:34:48 Sylwester Nawrocki wrote: > Hi Guennadi, > > On 10/08/2012 11:40 AM, Guennadi Liakhovetski wrote: > > On Fri, 5 Oct 2012, Sylwester Nawrocki wrote: > >> I would really like to see more than one user until we add any core code. > >> No that it couldn't be changed afterwards, but it would be nice to ensure > >> the concepts are right and proven in real life. > > > > Unfortunately I don't have any more systems on which I could easily enough > > try this. I've got a beagleboard with a camera, but I don't think I'm a > > particularly good candidate for implementing DT support for OMAP3 camera > > drivers;-) Apart from that I've only got soc-camera based systems, of > > which none are _really_ DT-ready... At best I could try an i.MX31 based > > board, but that doesn't have a very well developed .dts and that would be > > soc-camera too anyway. > > I certainly wouldn't expect you would do all the job. I mean it would be good > to possibly have some other developers adding device tree support based on that > new bindings and new infrastructure related to them. > > There have been recently some progress in device tree support for Exynos SoCs, > including common clock framework support and we hope to add FDT support to the > Samsung SoC camera devices during this kernel cycle, based on the newly designed > media bindings. This is going to be a second attempt, after our initial RFC from > May [1]. It would still be SoC specific implementation, but not soc-camera based. > > I wasn't a big fan of this asynchronous sub-devices probing, but it now seems > to be a most complete solution to me. I think it just need to be done right > at the v4l2-core so individual drivers don't get complicated too much. After investigating this some more I think I agree with that. There are some things where we should probably ask for advice from the i2c subsystem devs, I'm thinking of putting the driver back into the deferred-probe state in particular. Creating v4l2-core support for this is crucial as it is quite complex and without core support this is going to be a nightmare for drivers. Regards, Hans