mt9t031-VPFE integration issues...

mt9t031-VPFE integration issues...

[Karicheri, Muralidharan]

Hi Guennadi,

I am currently integrating latest MT9T031 driver to vpfe_capture driver and see following issues:-

1) Currently MT9T031 Kconfig configuration variable has a dependency on SOC_CAMERA. We need to remove this dependency since this sensor can be used on other platforms like DM6446/DM355/DM365. This is trivial and I can send a patch to remove the dependency.

2) The code still has reference to soc_camera_device and associated changes. I think this should be removed so that it can be used on other platforms as well. I am expecting these will go away once the bus parameter as well data format related RFCs are approved. If this is true, I can wait until the same is approved. If not, we need to work together so that this driver can be integrated with vpfe capture driver.

Please let me know what you think on this.

Regards,
Murali Karicheri
Software Design Engineer
Texas Instruments Inc.
Germantown, MD 20874
email: m-karicheri2@ti.com

Re: mt9t031-VPFE integration issues...

[Guennadi Liakhovetski]

Hi Murali

On Fri, 2 Oct 2009, Karicheri, Muralidharan wrote:

> I am currently integrating latest MT9T031 driver to vpfe_capture driver 
> and see following issues:-
> 
> 1) Currently MT9T031 Kconfig configuration variable has a dependency on 
> SOC_CAMERA. We need to remove this dependency since this sensor can be 
> used on other platforms like DM6446/DM355/DM365. This is trivial and I 
> can send a patch to remove the dependency.
> 
> 2) The code still has reference to soc_camera_device and associated 
> changes. I think this should be removed so that it can be used on other 
> platforms as well. I am expecting these will go away once the bus 
> parameter as well data format related RFCs are approved. If this is 
> true, I can wait until the same is approved. If not, we need to work 
> together so that this driver can be integrated with vpfe capture driver.

You're certainly right - soc-camera based drivers, including mt9t031, 
still depend on the soc-camera core, although most of the API has been 
converted to v4l2-subdev. Yes, the two biggest issues are bus-parameter 
and data-format negotiation. Also, we'll have to find a way to supply the 
data to the drivers, that is currently set in platform code. So, ideally, 
yes, we have to wait until the respective RFCs get implemented and until 
soc-camera gets completely converted, but if this is something urgent - 
maybe it would be acceptable to start modifying some drivers for "dual 
operation" - either with soc-camera API or in pure v4l2-subdev mode. This 
would be a bit of an extra work, and I don't know what others think about 
this. So, if you can wait, perhaps, this would be the best.

Thanks
Guennadi
---
Guennadi Liakhovetski

Re: mt9t031-VPFE integration issues...

[Guennadi Liakhovetski]

On Sat, 10 Nov 2012, Carmignani Dario wrote:

> Hi,
> 
> thanks for the answer.
> 
> Sorry, but I actually have not so clear how I can use soc-camera sensor driver
> with, for example, vpfe for dm365.
> 
> Can you please give me some hints?

Sorry, I'm not working with those systems. I don't even have access to 
non-soc-camera systems with soc-camera-based sensors. Basically you'll 
have to take a mainline camera-enabled dm365-based board (if there are 
any) as an example and use struct soc_camera_link as platform data for the 
ov772x driver. I think, Laurent (cc'ed) has a git-tree online somewhere 
with an example, using soc-camera originated sensor drivers with a 
non-soc-camera system. Try to find his mail about this on the list.

Thanks
Guennadi

> Thanks very much
> 
> Dario
> 
> > ------------------------------------------------------------------------
> > 
> > 	Guennadi Liakhovetski <mailto:g.liakhovetski@gmx.de>
> > 10 novembre 2012 13:44
> > 
> > 
> > > Hi,
> > > 
> > > I've just wrote you a while ago.
> > > 
> > > I'm working on a different sensor, but that is based on soc-camera
> > > framework
> > > as well: ov772x.
> > > 
> > > I've tried to remove in the ov772x driver the most part of the dependecy
> > > from
> > > soc-camera. But I guess that I've remove also the bus negotiation, without
> > > substituting it with something else.
> > > 
> > > Have you tried to do something similar on MT9t031 sensor?
> > 
> > In principle it's not too difficult to use soc-camera sensor drivers with
> > non-soc-camera hosts, it should be possible already now without any sensor
> > driver (most drivers, including ov772x; mt9t031 would be a bit more
> > difficult because of its power management, but if you don't need it, it
> > can be disabled) modifications. However, currencly such driver re-use is
> > not very elegant or natural. Work is in progress to improve it. So, you
> > can either try now or wait until those improvements are in place, don't
> > hold your breath though.
> > 
> > Thanks
> > Guennadi
> > 
> > > Thanks in advance
> > > 
> > > 
> > > Regards,
> > > 
> > > Dario
> > > 
> > 
> > ---
> > Guennadi Liakhovetski, Ph.D.
> > Freelance Open-Source Software Developer
> > http://www.open-technology.de/
> > 
> > ------------------------------------------------------------------------
> > 
> > 	Carmignani Dario <mailto:carmignani.dario@gmail.com>
> > 10 novembre 2012 12:32
> > 
> > 
> > Hi,
> > 
> > I've just wrote you a while ago.
> > 
> > I'm working on a different sensor, but that is based on soc-camera framework
> > as well: ov772x.
> > 
> > I've tried to remove in the ov772x driver the most part of the dependecy
> > from soc-camera. But I guess that I've remove also the bus negotiation,
> > without substituting it with something else.
> > 
> > Have you tried to do something similar on MT9t031 sensor?
> > 
> > Thanks in advance
> > 
> > 
> > Regards,
> > 
> > Dario
> 

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

Re: mt9t031-VPFE integration issues...

[Laurent Pinchart]

Hi Dario,

On Saturday 10 November 2012 16:58:05 Dario Carmignani wrote:
> Hi,
> Thank you.
> 
> The main issue I have is that when I use vpfe system and soc camera at the
> same time, I'm able to register ov772x i2c address with soc system, but vpfe
> seems not to be able to register ov772x device because it is now linked to
> the soc. But maybe I'm not doing the right thing.

I've hacked the ov772x driver for use with the OMAP3 ISP driver. You can find 
the patches at 
http://git.linuxtv.org/pinchartl/media.git/shortlog/refs/heads/board/beagle/ov772x. 
They're not upstreamable as-is, work is in progress to implement a proper 
solution, but that will still need time. I don't expect a solution in mainline 
before v3.9, if not v3.10.

> Il giorno 10-nov-2012 14:56, "Guennadi Liakhovetski" <g.liakhovetski@gmx.de>
> ha scritto:
> > On Sat, 10 Nov 2012, Carmignani Dario wrote:
> > > Hi,
> > > 
> > > thanks for the answer.
> > > 
> > > Sorry, but I actually have not so clear how I can use soc-camera sensor
> > > driver with, for example, vpfe for dm365.
> > > 
> > > Can you please give me some hints?
> > 
> > Sorry, I'm not working with those systems. I don't even have access to
> > non-soc-camera systems with soc-camera-based sensors. Basically you'll
> > have to take a mainline camera-enabled dm365-based board (if there are
> > any) as an example and use struct soc_camera_link as platform data for the
> > ov772x driver. I think, Laurent (cc'ed) has a git-tree online somewhere
> > with an example, using soc-camera originated sensor drivers with a
> > non-soc-camera system. Try to find his mail about this on the list.
> >
> > > > Guennadi Liakhovetski <mailto:g.liakhovetski@gmx.de>
> > > > 10 novembre 2012 13:44
> > > > 
> > > > > Hi,
> > > > > 
> > > > > I've just wrote you a while ago.
> > > > > 
> > > > > I'm working on a different sensor, but that is based on soc-camera
> > > > > framework as well: ov772x.
> > > > > 
> > > > > I've tried to remove in the ov772x driver the most part of the
> > > > > dependecy from soc-camera. But I guess that I've remove also the bus
> > > > > negotiation, without substituting it with something else.
> > > > > 
> > > > > Have you tried to do something similar on MT9t031 sensor?
> > > > 
> > > > In principle it's not too difficult to use soc-camera sensor drivers
> > > > with non-soc-camera hosts, it should be possible already now without
> > > > any sensor driver (most drivers, including ov772x; mt9t031 would be a
> > > > bit more difficult because of its power management, but if you don't
> > > > need it, it can be disabled) modifications. However, currencly such
> > > > driver re-use is not very elegant or natural. Work is in progress to
> > > > improve it. So, you can either try now or wait until those
> > > > improvements are in place, don't hold your breath though.

-- 
Regards,

Laurent Pinchart