Thank you for your kind explanation Hans. Problem is omap3 camera subsystem is making device node for every int device attached to it. Before I have been using v4l2 int device, I implemented S_INPUT/G_INPUT/ENUMINPUT by my own for other CPUs like S3C64XX (just for demo..not opened on public domain yet) In that case, I considered camera interface as a capture device, and every camera devices as input devices for capture device. So using enuminput I could query how many devices do I have for input, and even camera device's name could be get. I made only one device node for camera interface because it was exactly camera interface that I open, not camera module attached on it. Furthermore, CPU's camera video processing H/W cannot process data from multiple cameras at the same time. So no need to make device node for every single camera module attached on it. For these kinds of reason, I think also omap3 camera subsystem should make only one device node for the same category of int device(or subdev for now?). I mean single device node for sensors, single device node for lens controllers, single device node for strobes. I hope I made myself clear. Honestly it is quite hard to explain (even in my language) Cheers,
Nate On Tue, Mar 3, 2009 at 4:36 PM, Hans Verkuil <hverk...@xs4all.nl> wrote: > On Tuesday 03 March 2009 06:13:11 DongSoo(Nathaniel) Kim wrote: >> Thank you for your reply. >> >> This is quite confusing because in case of mine, I wanna make >> switchable between different cameras attached to omap camera >> interface. >> Which idea do I have to follow? Comparing with multiple video input >> devices and multiple cameras attached to single camera interface is >> giving me no answer. >> >> Perhaps multiple cameras with single camera interface couldn't make >> sense at the first place because single camera interface can go with >> only one camera module at one time. >> But we are using like that. I mean dual cameras with single camera >> interface. There is no choice except that when we are using dual >> camera without stereo camera controller. > > If you have multiple inputs (cameras in this case) that the user can choose > from, then you need to implement S_INPUT/G_INPUT/ENUMINPUTS. That's what > they are there for. Any decent V4L2 app should support these ioctls. > >> By the way, I cannot find any API documents about >> VIDIOC_INT_S_VIDEO_ROUTING but it seems to be all about "how to route >> between input device with output device". > > The description of this internal ioctl is in v4l2-common.h. It is used to > tell the i2c module how it is hooked up to the rest of the system. I.e. > what pin(s) is used for the input signal and what pin(s) is used for the > output signal. > > Typically the main v4l2 driver will map a user-level input (as set with > VIDIOC_S_INPUT) to the low-level routing information and pass that on to > the i2c device using VIDIOC_INT_S_VIDEO_ROUTING. > > Regards, > > Hans > >> What exactly I need is "how to make switchable with multiple camera as >> an input for camera interface", which means just about an input >> device. In my opinion, those are different issues each other..(Am I >> right?) >> Cheers, >> >> Nate >> >> On Tue, Mar 3, 2009 at 12:53 PM, Hiremath, Vaibhav <hvaib...@ti.com> > wrote: >> > Thanks, >> > Vaibhav Hiremath >> > >> >> -----Original Message----- >> >> From: linux-omap-ow...@vger.kernel.org [mailto:linux-omap- >> >> ow...@vger.kernel.org] On Behalf Of DongSoo(Nathaniel) Kim >> >> Sent: Tuesday, March 03, 2009 8:18 AM >> >> To: Tuukka.O Toivonen >> >> Cc: Aguirre Rodriguez, Sergio Alberto; linux-o...@vger.kernel.org; >> >> Ailus Sakari (Nokia-D/Helsinki); Nagalla, Hari >> >> Subject: Re: [REVIEW PATCH 11/14] OMAP34XXCAM: Add driver >> >> >> >> Hi Tuukka, >> >> >> >> I understand that it is a huge thing to support VIDIOC_S_INPUT. >> >> But without that, we don't have any proper "V4L2" api to get >> >> information about how many devices are attached to camera interface, >> >> and names of input devices...and so on. Because VIDIOC_ENUMINPUT and >> >> VIDIOC_G_INPUT needs VIDIOC_S_INPUT for prior. Of course we can >> >> refer >> >> to sysfs, but using only single set of APIs like V4L2 looks more >> >> decent. >> >> >> >> What do you think about this? >> >> If you think that it is a big burden, can I make a patch for this? >> >> Cheers, >> > >> > [Hiremath, Vaibhav] You may want to refer to the thread on this >> > subject. >> > >> > http://marc.info/?l=linux-omap&m=122772175002777&w=2 >> > http://marc.info/?l=linux-omap&m=122823846806440&w=2 >> > >> >> Nate >> >> >> >> On Mon, Feb 23, 2009 at 5:50 PM, Tuukka.O Toivonen >> >> >> >> <tuukka.o.toivo...@nokia.com> wrote: >> >> > On Monday 23 February 2009 10:08:54 ext DongSoo(Nathaniel) Kim >> >> >> >> wrote: >> >> >> So, logically it does not make sense with making device nodes of >> >> >> >> every >> >> >> >> >> single slave attached with OMAP3camera interface. Because they >> >> >> >> can't >> >> >> >> >> be opened at the same time,even if it is possible it should not >> >> >> >> work >> >> >> >> >> properly. >> >> >> >> >> >> So.. how about making only single device node like /dev/video0 >> >> >> >> for >> >> >> >> >> OMAP3 camera interface and make it switchable through V4L2 API. >> >> >> >> Like >> >> >> >> >> VIDIOC_S_INPUT? >> >> > >> >> > You are right that if the OMAP3 has several camera sensors >> >> >> >> attached >> >> >> >> > to its camera interface, generally just one can be used at once. >> >> > >> >> > However, from user's perspective those are still distinct >> >> > cameras. Many v4l2 applications don't support VIDIOC_S_INPUT >> >> > or at least it will be more difficult to use than just pointing >> >> > an app to the correct video device. Logically they are two >> >> > independent cameras, which can't be used simultaneously >> >> > due to HW restrictions. >> >> > >> >> > - Tuukka >> >> >> >> -- >> >> ======================================================== >> >> DongSoo(Nathaniel), Kim >> >> Engineer >> >> Mobile S/W Platform Lab. S/W centre >> >> Telecommunication R&D Centre >> >> Samsung Electronics CO., LTD. >> >> e-mail : dongsoo....@gmail.com >> >> dongsoo45....@samsung.com >> >> ======================================================== >> >> -- >> >> To unsubscribe from this list: send the line "unsubscribe linux- >> >> omap" in >> >> the body of a message to majord...@vger.kernel.org >> >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > -- > Hans Verkuil - video4linux developer - sponsored by TANDBERG > -- ======================================================== DongSoo(Nathaniel), Kim Engineer Mobile S/W Platform Lab. S/W centre Telecommunication R&D Centre Samsung Electronics CO., LTD. e-mail : dongsoo....@gmail.com dongsoo45....@samsung.com ======================================================== -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
