Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754384Ab3EYJR5 (ORCPT ); Sat, 25 May 2013 05:17:57 -0400 Received: from mail-ve0-f169.google.com ([209.85.128.169]:61210 "EHLO mail-ve0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751664Ab3EYJRy (ORCPT ); Sat, 25 May 2013 05:17:54 -0400 MIME-Version: 1.0 In-Reply-To: <519F4AE7.8000003@gmail.com> References: <1368710287-8741-1-git-send-email-prabhakar.csengg@gmail.com> <519F4AE7.8000003@gmail.com> From: Prabhakar Lad Date: Sat, 25 May 2013 14:47:33 +0530 Message-ID: Subject: Re: [PATCH RFC v2] media: OF: add sync-on-green endpoint property To: Sylwester Nawrocki Cc: LMML , LKML , DLOS , Mauro Carvalho Chehab , Hans Verkuil , Laurent Pinchart , Guennadi Liakhovetski , Sakari Ailus , Grant Likely , Rob Herring , Rob Landley , devicetree-discuss@lists.ozlabs.org, linux-doc@vger.kernel.org, Kyungmin Park Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2817 Lines: 85 Hi Sylwester, On Fri, May 24, 2013 at 4:41 PM, Sylwester Nawrocki wrote: > Prabhakar, > > > On 05/16/2013 03:18 PM, Lad Prabhakar wrote: >> >> From: Lad, Prabhakar >> >> This patch adds "sync-on-green" property as part of >> endpoint properties and also support to parse them in the parser. > > >> --- a/Documentation/devicetree/bindings/media/video-interfaces.txt >> +++ b/Documentation/devicetree/bindings/media/video-interfaces.txt >> @@ -101,6 +101,8 @@ Optional endpoint properties >> array contains only one entry. >> - clock-noncontinuous: a boolean property to allow MIPI CSI-2 >> non-continuous >> clock mode. >> +-sync-on-green: a boolean property indicating to sync with the green >> signal in >> + RGB. > > > Are you sure this is what you need for the TVP7002 chip ? > Yes > I think we should differentiate between analog and digital signals and the > related > device's configuration. AFAIU for the analog part there can be various video > sychronisation methods, i.e. ways in which the synchronisation signals are > transmitted along side the video component (RGB or luma/chroma) signals. > According > to [1] (presumably not most reliable source of information) there are > following > methods of transmitting sync signals: > > - Separate sync > - Composite sync > - Sync-on-green (SOG) > - Sync-on-luminance > - Sync-on-composite > > And all these seem to refer to analog video signal. > I was about to add all these but as per Laurent mentioned we can add this whenever there is a need of it. > From looking at Figure 8 "TVP7002 Application Example" in the TVP7002's > datasheet > ([2], p. 52) and your initial TVP7002 patches it looks like what you want is > to > specify polarity of the SOGOUT signal, so the processor that receives this > signal > can properly interpret it, is it correct ? > Yes > If so then wouldn't it be more appropriate to define e.g. 'sog-active' > property > and media bus flags: > V4L2_MBUS_SYNC_ON_GREEN_ACTIVE_LOW > V4L2_MBUS_SYNC_ON_GREEN_ACTIVE_HIGH > ? > Agreed I'll add these flags. > And for synchronisation method on the analog part we could perhaps define > 'component-sync' or similar property that would enumerate all possible > synchronisation methods. We might as well use separate boolean properties, > but I'm a bit concerned about the increasing number of properties that need > to be parsed for each parallel video bus "endpoint". > I am not clear on it can please elaborate more on this. Regards, --Prabhakar Lad -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/