From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mailout3.w1.samsung.com ([210.118.77.13]:13667 "EHLO mailout3.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752834Ab1ISIhT (ORCPT ); Mon, 19 Sep 2011 04:37:19 -0400 MIME-version: 1.0 Content-transfer-encoding: 7BIT Content-type: text/plain; charset=UTF-8 Received: from euspt1 ([210.118.77.13]) by mailout3.w1.samsung.com (Sun Java(tm) System Messaging Server 6.3-8.04 (built Jul 29 2009; 32bit)) with ESMTP id <0LRR000VDHA57J00@mailout3.w1.samsung.com> for linux-media@vger.kernel.org; Mon, 19 Sep 2011 09:37:17 +0100 (BST) Received: from linux.samsung.com ([106.116.38.10]) by spt1.w1.samsung.com (iPlanet Messaging Server 5.2 Patch 2 (built Jul 14 2004)) with ESMTPA id <0LRR00LXKHA4S5@spt1.w1.samsung.com> for linux-media@vger.kernel.org; Mon, 19 Sep 2011 09:37:17 +0100 (BST) Date: Mon, 19 Sep 2011 10:37:16 +0200 From: Sylwester Nawrocki Subject: Re: [PATCH/RFC 1/2] v4l2: Add the parallel bus HREF signal polarity flags In-reply-to: <201109190102.04870.laurent.pinchart@ideasonboard.com> To: Laurent Pinchart Cc: Sylwester Nawrocki , linux-media@vger.kernel.org, m.szyprowski@samsung.com, kyungmin.park@samsung.com, g.liakhovetski@gmx.de, sw0312.kim@samsung.com, riverful.kim@samsung.com Message-id: <4E76FF3C.9020703@samsung.com> References: <1316194123-21185-1-git-send-email-s.nawrocki@samsung.com> <201109171254.49003.laurent.pinchart@ideasonboard.com> <4E748D82.8040006@gmail.com> <201109190102.04870.laurent.pinchart@ideasonboard.com> Sender: linux-media-owner@vger.kernel.org List-ID: On 09/19/2011 01:02 AM, Laurent Pinchart wrote: > On Saturday 17 September 2011 14:07:30 Sylwester Nawrocki wrote: >> On 09/17/2011 12:54 PM, Laurent Pinchart wrote: >>> On Friday 16 September 2011 19:28:42 Sylwester Nawrocki wrote: >>>> HREF is a signal indicating valid data during single line transmission. >>>> Add corresponding flags for this signal to the set of mediabus signal >>>> polarity flags. >>> >>> So that's a data valid signal that gates the pixel data ? The OMAP3 ISP >>> has a >> >> Yes, it's "horizontal window reference" signal, it's well described in this >> datasheet: http://www.morninghan.com/pdf/OV2640FSL_DS_(1_3).pdf > > In that specific case I would likely connect to HREF signal to the ISP HSYNC > signal and ignore the sensor HSYNC signal completely :-) > >> AFAICS there can be also its vertical counterpart - VREF. > > OK, your HREF signal is thus completely unrelated to my DVAL signal. DVAL > really qualifies pixel. For instance, if the sensor outputs pixels at half the > pixel rate, DVAL would switch at every pixel clock cycle during a line. Yeah, sounds it's entirely different. > >> Many devices seem to use this terminology. However, I realize, not all, as >> you're pointing out. So perhaps it's time for some naming contest now.. >> :-) >> >>> similar signal called WEN, and I've seen other chips using DVAL. Your >>> patch looks good to me, except maybe for the signal name that could be >>> made a bit more explicit (I'm not sure what most chips use though). >> >> I'm pretty OK with HREF/VREF. But I'm open to any better suggestions. >> >> Maybe >> >> V4L2_MBUS_LINE_VALID_ACTIVE_HIGH >> V4L2_MBUS_LINE_VALID_ACTIVE_LOW >> >> V4L2_MBUS_FRAME_VALID_ACTIVE_HIGH >> V4L2_MBUS_FRAME_VALID_ACTIVE_LOW >> >> ? >> Some of Aptina sensor datasheets describes those signals as >> LINE_VALID/FRAME_VALID, (www.aptina.com/assets/downloadDocument.do?id=76). > > LINE_VALID/FRAME_VALID are HSYNC/VSYNC. I would say these are rather inverted horizontal/vertical blanking signal. > >>>> Signed-off-by: Sylwester Nawrocki >>>> Signed-off-by: Kyungmin Park >>>> --- >>>> >>>> include/media/v4l2-mediabus.h | 14 ++++++++------ >>>> 1 files changed, 8 insertions(+), 6 deletions(-) >>>> >>>> diff --git a/include/media/v4l2-mediabus.h >>>> b/include/media/v4l2-mediabus.h index 6114007..41d8771 100644 >>>> --- a/include/media/v4l2-mediabus.h >>>> +++ b/include/media/v4l2-mediabus.h >>>> @@ -26,12 +26,14 @@ >>>> >>>> /* Note: in BT.656 mode HSYNC and VSYNC are unused */ >> >> I've forgotten to update this: >> >> /* Note: in BT.656 mode HSYNC, HREF and VSYNC are unused */ >> >>>> #define V4L2_MBUS_HSYNC_ACTIVE_HIGH (1<< 2) >>>> #define V4L2_MBUS_HSYNC_ACTIVE_LOW (1<< 3) >>>> >>>> -#define V4L2_MBUS_VSYNC_ACTIVE_HIGH (1<< 4) >>>> -#define V4L2_MBUS_VSYNC_ACTIVE_LOW (1<< 5) >>>> -#define V4L2_MBUS_PCLK_SAMPLE_RISING (1<< 6) >>>> -#define V4L2_MBUS_PCLK_SAMPLE_FALLING (1<< 7) >>>> -#define V4L2_MBUS_DATA_ACTIVE_HIGH (1<< 8) >>>> -#define V4L2_MBUS_DATA_ACTIVE_LOW (1<< 9) >>>> +#define V4L2_MBUS_HREF_ACTIVE_HIGH (1<< 4) >>>> +#define V4L2_MBUS_HREF_ACTIVE_LOW (1<< 5) >>>> +#define V4L2_MBUS_VSYNC_ACTIVE_HIGH (1<< 6) >>>> +#define V4L2_MBUS_VSYNC_ACTIVE_LOW (1<< 7) >>>> +#define V4L2_MBUS_PCLK_SAMPLE_RISING (1<< 8) >>>> +#define V4L2_MBUS_PCLK_SAMPLE_FALLING (1<< 9) >>>> +#define V4L2_MBUS_DATA_ACTIVE_HIGH (1<< 10) >>>> +#define V4L2_MBUS_DATA_ACTIVE_LOW (1<< 11) > Thanks -- Sylwester Nawrocki Samsung Poland R&D Center