Hi Sakari, On 12/31/2011 12:35 PM, Sakari Ailus wrote: > On Sat, Dec 31, 2011 at 02:57:31PM +0800, Scott Jiang wrote: >> 2011/12/31 Sakari Ailus <sakari.ailus@xxxxxx>: >>> On Fri, Dec 30, 2011 at 03:20:43PM +0800, Scott Jiang wrote: >>>> Our bridge driver needs to know line clock count including active >>>> lines and blanking area. >>>> I can compute active clock count according to pixel format, but how >>>> can I get this in blanking area in current framework? >>> >>> Such information is not available currently over the V4L2 subdev interface. >>> Please see this patchset: >>> >>> <URL:http://www.spinics.net/lists/linux-media/msg41765.html> >>> >>> Patches 7 and 8 are probably the most interesting for you. This is an RFC >>> patchset so the final implementation could well still change. >>> >> Hi Sakari, >> >> Thanks for your reply. Your patch added VBLANK and HBLANK control, but >> my case isn't a user control. >> That is to say, you can't specify a blanking control value for sensor. > > I the case of your bridge, that may not be possible, but that's the only one > I've heard of so I think it's definitely a special case. In that case the > sensor driver can't be allowed to change the blanking periods while > streaming is ongoing. I agree, it's just a matter of adding proper logic at the sensor driver. However it might be a bit tricky, the bridge would have to validate blanking values before actually enabling streaming. > framesamples proposed by Sylwester for v4l2_mbus_framefmt could, and > probably should, be exposed as a control with similar property. Yeah, I'm going to try to add it to your proposed image source control class. >> And you added pixel clock rate in mbus format, I think if I add two >> more parametres such as VBLANK lines and HBLANK clocks I can solve >> this problem. In fact, active lines and blanking lines are essential >> params to define an image. > > Only the active lines and rows are, blanking period is just an idle period > where no image data is transferred. It does not affect the resulting image > in any way. -- Regards, Sylwester -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
