Re: Migrate from soc_camera to v4l2

Re: Migrate from soc_camera to v4l2

[Guennadi Liakhovetski]

On Wed, 13 Jul 2011, LBM wrote:

> my dear Guennadi
>      I'm wrong about that "v4l2-int-device",maybe it just "V4L2".  
>        Now i have a board of OMAP3530 and a cmos camera MT9M111,so i want to get the image from the mt9m111.
>  and ,I want to use the V4L2 API. But in the linux kernel 2.6.38,the driver of the mt9m111 is  a soc_camera.I see some thing about how to convert the soc_camera to V4L2,like "soc-camera: (partially) convert to v4l2-(sub)dev API".
>       Can you tell me how to migrate from soc_camera to v4l2,and
>      or do you tell me some experience about that?

Currently there's no standard way to make a driver to work with both 
soc-camera and (pure) v4l2-subdev APIs. It is being worked on:

http://www.spinics.net/lists/linux-media/msg34878.html

and, hopefully, beginning with the next kernel version 3.1 it will become 
at least theoretically possible. For now you just have to hack the driver 
yourself for your local uses by removing all soc-camera specific code and 
replacing it with your own glue, something along these lines:

http://thread.gmane.org/gmane.linux.drivers.video-input-infrastructure/11486/focus=11691

Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/

Re: Migrate from soc_camera to v4l2

[Teresa Gamez]

Hello Guennadi,

Am Mittwoch, den 13.07.2011, 09:14 +0200 schrieb Guennadi Liakhovetski:
> On Wed, 13 Jul 2011, LBM wrote:
> 
> > my dear Guennadi
> >      I'm wrong about that "v4l2-int-device",maybe it just "V4L2".  
> >        Now i have a board of OMAP3530 and a cmos camera MT9M111,so i want to get the image from the mt9m111.
> >  and ,I want to use the V4L2 API. But in the linux kernel 2.6.38,the driver of the mt9m111 is  a soc_camera.I see some thing about how to convert the soc_camera to V4L2,like "soc-camera: (partially) convert to v4l2-(sub)dev API".
> >       Can you tell me how to migrate from soc_camera to v4l2,and
> >      or do you tell me some experience about that?
> 
> Currently there's no standard way to make a driver to work with both 
> soc-camera and (pure) v4l2-subdev APIs. It is being worked on:
> 
> http://www.spinics.net/lists/linux-media/msg34878.html
> 
> and, hopefully, beginning with the next kernel version 3.1 it will become 
> at least theoretically possible. For now you just have to hack the driver 
> yourself for your local uses by removing all soc-camera specific code and 
> replacing it with your own glue, something along these lines:

We are also interested in the support of the MT9M111 and MT9V022 for OMAP-4460/OMAP-4430/OMAP-3525.
I have not taken a deeper look at it yet. But what do you mean by theoretically possible?
Could it work out of the box? Or is there more work to do? 

Regards,
Teresa

> http://thread.gmane.org/gmane.linux.drivers.video-input-infrastructure/11486/focus=11691
> 
> Thanks
> Guennadi
> ---
> Guennadi Liakhovetski, Ph.D.
> Freelance Open-Source Software Developer
> http://www.open-technology.de/
> --
> To unsubscribe from this list: send the line "unsubscribe linux-media" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: Migrate from soc_camera to v4l2

[Laurent Pinchart]

Hi Teresa,

On Friday 15 July 2011 15:37:19 Teresa Gamez wrote:
> Am Mittwoch, den 13.07.2011, 09:14 +0200 schrieb Guennadi Liakhovetski:
> > On Wed, 13 Jul 2011, LBM wrote:
> > > my dear Guennadi
> > > 
> > >      I'm wrong about that "v4l2-int-device",maybe it just "V4L2".
> > >      
> > >        Now i have a board of OMAP3530 and a cmos camera MT9M111,so i
> > >        want to get the image from the mt9m111.
> > >  
> > >  and ,I want to use the V4L2 API. But in the linux kernel 2.6.38,the
> > >  driver of the mt9m111 is  a soc_camera.I see some thing about how to
> > >  convert the soc_camera to V4L2,like "soc-camera: (partially) convert
> > >  to v4l2-(sub)dev API".
> > >  
> > >       Can you tell me how to migrate from soc_camera to v4l2,and
> > >      
> > >      or do you tell me some experience about that?
> > 
> > Currently there's no standard way to make a driver to work with both
> > soc-camera and (pure) v4l2-subdev APIs. It is being worked on:
> > 
> > http://www.spinics.net/lists/linux-media/msg34878.html
> > 
> > and, hopefully, beginning with the next kernel version 3.1 it will become
> > at least theoretically possible. For now you just have to hack the driver
> > yourself for your local uses by removing all soc-camera specific code and
> 
> > replacing it with your own glue, something along these lines:
> We are also interested in the support of the MT9M111 and MT9V022 for
> OMAP-4460/OMAP-4430/OMAP-3525. I have not taken a deeper look at it yet.
> But what do you mean by theoretically possible? Could it work out of the
> box? Or is there more work to do?

The OMAP4 has unfortunately no V4L2 driver, so OMAP4 support is pretty much 
impossible today. The situation might change, but unless someone is willing to 
fund a couple of developers to work on this full time, I don't expect a proper 
OMAP4 V4L2 driver before at least one year.

-- 
Regards,

Laurent Pinchart

Re: Migrate from soc_camera to v4l2

[Guennadi Liakhovetski]

Hello Teresa

On Fri, 15 Jul 2011, Teresa Gamez wrote:

> Hello Guennadi,
> 
> Am Mittwoch, den 13.07.2011, 09:14 +0200 schrieb Guennadi Liakhovetski:
> > On Wed, 13 Jul 2011, LBM wrote:
> > 
> > > my dear Guennadi
> > >      I'm wrong about that "v4l2-int-device",maybe it just "V4L2".  
> > >        Now i have a board of OMAP3530 and a cmos camera MT9M111,so i want to get the image from the mt9m111.
> > >  and ,I want to use the V4L2 API. But in the linux kernel 2.6.38,the driver of the mt9m111 is  a soc_camera.I see some thing about how to convert the soc_camera to V4L2,like "soc-camera: (partially) convert to v4l2-(sub)dev API".
> > >       Can you tell me how to migrate from soc_camera to v4l2,and
> > >      or do you tell me some experience about that?
> > 
> > Currently there's no standard way to make a driver to work with both 
> > soc-camera and (pure) v4l2-subdev APIs. It is being worked on:
> > 
> > http://www.spinics.net/lists/linux-media/msg34878.html
> > 
> > and, hopefully, beginning with the next kernel version 3.1 it will become 
> > at least theoretically possible. For now you just have to hack the driver 
> > yourself for your local uses by removing all soc-camera specific code and 
> > replacing it with your own glue, something along these lines:
> 
> We are also interested in the support of the MT9M111 and MT9V022 for OMAP-4460/OMAP-4430/OMAP-3525.
> I have not taken a deeper look at it yet. But what do you mean by theoretically possible?

By this I mean, that most important APIs, required for a "proper" 
conversion, suitable for the mainline, should be in place by then. 
Although there still might be one thing, preventing this: controls. 
Unfortunately, it looks like Hans haven't found the time yet to submit a 
new version of his soc-camera conversion to the new v4l2 control 
framework, and even if he did, it would be very difficult for me ATM to 
find time to review, merge and push it. So, I'm not sure if it would be 
possible to do a proper conversion without that, maybe not, then we'd 
have to work on controls conversion too.

> Could it work out of the box? Or is there more work to do? 

No, first the APIs have to be made compatible, then individual drivers 
have to be converted one by one.

Thanks
Guennadi

> 
> Regards,
> Teresa
> 
> > http://thread.gmane.org/gmane.linux.drivers.video-input-infrastructure/11486/focus=11691
> > 
> > Thanks
> > Guennadi
> > ---
> > Guennadi Liakhovetski, Ph.D.
> > Freelance Open-Source Software Developer
> > http://www.open-technology.de/
> > --
> > To unsubscribe from this list: send the line "unsubscribe linux-media" in
> > the body of a message to majordomo@vger.kernel.org
> > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 
> 

---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/

Re: Migrate from soc_camera to v4l2

[Hans Verkuil]

On Friday, July 15, 2011 17:31:13 Guennadi Liakhovetski wrote:
> Hello Teresa
> 
> On Fri, 15 Jul 2011, Teresa Gamez wrote:
> 
> > Hello Guennadi,
> > 
> > Am Mittwoch, den 13.07.2011, 09:14 +0200 schrieb Guennadi Liakhovetski:
> > > On Wed, 13 Jul 2011, LBM wrote:
> > > 
> > > > my dear Guennadi
> > > >      I'm wrong about that "v4l2-int-device",maybe it just "V4L2".  
> > > >        Now i have a board of OMAP3530 and a cmos camera MT9M111,so i want to get the image from the mt9m111.
> > > >  and ,I want to use the V4L2 API. But in the linux kernel 2.6.38,the driver of the mt9m111 is  a soc_camera.I see some thing about how to convert the soc_camera to V4L2,like "soc-camera: (partially) convert to v4l2-(sub)dev API".
> > > >       Can you tell me how to migrate from soc_camera to v4l2,and
> > > >      or do you tell me some experience about that?
> > > 
> > > Currently there's no standard way to make a driver to work with both 
> > > soc-camera and (pure) v4l2-subdev APIs. It is being worked on:
> > > 
> > > http://www.spinics.net/lists/linux-media/msg34878.html
> > > 
> > > and, hopefully, beginning with the next kernel version 3.1 it will become 
> > > at least theoretically possible. For now you just have to hack the driver 
> > > yourself for your local uses by removing all soc-camera specific code and 
> > > replacing it with your own glue, something along these lines:
> > 
> > We are also interested in the support of the MT9M111 and MT9V022 for OMAP-4460/OMAP-4430/OMAP-3525.
> > I have not taken a deeper look at it yet. But what do you mean by theoretically possible?
> 
> By this I mean, that most important APIs, required for a "proper" 
> conversion, suitable for the mainline, should be in place by then. 
> Although there still might be one thing, preventing this: controls. 
> Unfortunately, it looks like Hans haven't found the time yet to submit a 
> new version of his soc-camera conversion to the new v4l2 control 
> framework, and even if he did, it would be very difficult for me ATM to 
> find time to review, merge and push it.

This has been delayed by discussions on how to handle autogain/gain-like
controls (and my vacation as well). As soon as that has been resolved I can
continue with this.

A tree with a fairly up-to-date control conversion is here:

http://git.linuxtv.org/hverkuil/media_tree.git/shortlog/refs/heads/soc-camera

Missing is any support for the new control event, but that can wait until
the poll() changes are merged anyway.

> So, I'm not sure if it would be 
> possible to do a proper conversion without that, maybe not, then we'd 
> have to work on controls conversion too.

I'm pretty sure you need this.

Regards,

	Hans

> > Could it work out of the box? Or is there more work to do? 
> 
> No, first the APIs have to be made compatible, then individual drivers 
> have to be converted one by one.
> 
> Thanks
> Guennadi
> 
> > 
> > Regards,
> > Teresa
> > 
> > > http://thread.gmane.org/gmane.linux.drivers.video-input-infrastructure/11486/focus=11691
> > > 
> > > Thanks
> > > Guennadi
> > > ---
> > > Guennadi Liakhovetski, Ph.D.
> > > Freelance Open-Source Software Developer
> > > http://www.open-technology.de/
> > > --
> > > To unsubscribe from this list: send the line "unsubscribe linux-media" in
> > > the body of a message to majordomo@vger.kernel.org
> > > More majordomo info at  http://vger.kernel.org/majordomo-info.html
> > 
> > 
> 
> ---
> Guennadi Liakhovetski, Ph.D.
> Freelance Open-Source Software Developer
> http://www.open-technology.de/
> --
> To unsubscribe from this list: send the line "unsubscribe linux-media" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 
>