From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from perceval.ideasonboard.com ([95.142.166.194]:56911 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753078Ab2BQXWx (ORCPT ); Fri, 17 Feb 2012 18:22:53 -0500 From: Laurent Pinchart To: Sylwester Nawrocki Cc: Sakari Ailus , linux-media@vger.kernel.org, g.liakhovetski@gmx.de, m.szyprowski@samsung.com, riverful.kim@samsung.com, sw0312.kim@samsung.com, Kyungmin Park Subject: Re: [RFC/PATCH 1/6] V4L: Add V4L2_MBUS_FMT_VYUY_JPEG_I1_1X8 media bus format Date: Sat, 18 Feb 2012 00:22:06 +0100 Message-ID: <15287242.Y7HLBiloy7@avalon> In-Reply-To: <4F3E6395.4070208@samsung.com> References: <1329416639-19454-1-git-send-email-s.nawrocki@samsung.com> <20120216194615.GF7784@valkosipuli.localdomain> <4F3E6395.4070208@samsung.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-media-owner@vger.kernel.org List-ID: Hi Sylwester, On Friday 17 February 2012 15:26:29 Sylwester Nawrocki wrote: > On 02/16/2012 08:46 PM, Sakari Ailus wrote: > > On Thu, Feb 16, 2012 at 07:23:54PM +0100, Sylwester Nawrocki wrote: > >> This patch adds media bus pixel code for the interleaved JPEG/YUYV image > >> format used by S5C73MX Samsung cameras. The interleaved image data is > >> transferred on MIPI-CSI2 bus as User Defined Byte-based Data. > >> > >> Signed-off-by: Sylwester Nawrocki > >> Signed-off-by: Kyungmin Park > >> --- > >> > >> include/linux/v4l2-mediabus.h | 3 +++ > >> 1 files changed, 3 insertions(+), 0 deletions(-) > >> > >> diff --git a/include/linux/v4l2-mediabus.h > >> b/include/linux/v4l2-mediabus.h > >> index 5ea7f75..c2f0e4e 100644 > >> --- a/include/linux/v4l2-mediabus.h > >> +++ b/include/linux/v4l2-mediabus.h > >> @@ -92,6 +92,9 @@ enum v4l2_mbus_pixelcode { > >> > >> /* JPEG compressed formats - next is 0x4002 */ > >> V4L2_MBUS_FMT_JPEG_1X8 = 0x4001, > >> > >> + > >> + /* Interleaved JPEG and YUV formats - next is 0x4102 */ > >> + V4L2_MBUS_FMT_VYUY_JPEG_I1_1X8 = 0x4101, > >> > >> }; Please remember to update Documentation/DocBook/media/v4l/subdev-formats.xml. > > Thanks for the patch. Just a tiny comment: > > > > I'd go with a new hardware-specific buffer range, e.g. 0x5000. > > Sure, that makes more sense. But I guess you mean "format" not "buffer" > range ? > > > Guennadi also proposed an interesting idea: a "pass-through" format. Does > > your format have dimensions that the driver would use for something or is > > that just a blob? > > It's just a blob for the drivers, dimensions may be needed for subdevs to > compute overall size of data for example. But the host driver, in case of > Samsung devices, basically just needs to know the total size of frame data. > > I'm afraid the host would have to additionally configure subdevs in the data > pipeline in case of hardware-specific format, when we have used a single > binary blob media bus format identifier. For example MIPI-CSI2 data format > would have to be set up along the pipeline. There might be more attributes > in the future like this. Not sure if we want to go that path ? > > I'll try and see how it would look like with a single "pass-through" format. > Probably using g/s_mbus_config operations ? I'm not sure yet how all this should be handled exactly, but I'm pretty sure I don't want the CSI2 receiver drivers to handle all the vendor-specific blob- like formats explicitly. For instance your sensor could be used with the OMAP3 ISP, and I don't want to add support for V4L2_MBUS_FMT_VYUY_JPEG_I1_1X8 to the OMAP3 ISP CSI2 driver. We need a way for CSI2 receiver drivers to map blob formats automatically. Enumeration also needs to be handled, which makes the problem even more complex. -- Regards, Laurent Pinchart