Re: [RFC PATCH] [media] mt9v032: Add support for mt9v022 and mt9v024

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hello,

On Wednesday 28 May 2014 12:07:57 Guennadi Liakhovetski wrote:
> On Wed, 28 May 2014, Philipp Zabel wrote:
> > Am Dienstag, den 27.05.2014, 21:48 +0200 schrieb Guennadi Liakhovetski:
> > > On Mon, 26 May 2014, Philipp Zabel wrote:
> > > > From the looks of it, mt9v022 and mt9v032 are very similar,
> > > > as are mt9v024 and mt9v034. With minimal changes it is possible
> > > > to support mt9v02[24] with the same driver.
> > > 
> > > Are you aware of drivers/media/i2c/soc_camera/mt9v022.c?
> > 
> > Yes. Unfortunately this driver can't be used in a system without
> > soc_camera. It uses soc_camera helpers and doesn't implement pad ops
> > among others.
> 
> As I mentioned many times, this compatibility is a matter of someone just
> needing and finally doing this. If you need this, please, extend the
> mt9v022 driver to also work with non soc-camera hosts, if you need any
> help - please feel free to ask, I can send you my conversion code, that
> I've done for ov772x, but never managed to finalise testing,
> unfortunately.
>
> > > With this patch you'd duplicate support for both mt9v022 and mt9v024,
> > > which doesn't look like a good idea to me.
> > 
> > While this is true, given that the mt9v02x/3x sensors are so similar,
> > the support is already duplicated in all but name.
> > Would you suggest we should try to merge the mt9v032 and mt9v022
> > drivers?
> 
> Out of 3 options:
> 
> 1. extend mt9v022 to work with non soc-camera hosts
> 2. extend mt9v032 to also support mt9v022 and mt9v024
> 3. merge both mt9v022 and mt9v032 drivers
> 
> option 2 seems the worst to me. I'm ok with either 1 or 3, whereas 3 is
> more difficult than 1.

This topic has been discussed over and over. It indeed "just" requires someone 
to do it, although it might be more complex than that sounds.

We need to fix the infrastructure to make sensor drivers completely unaware of 
soc-camera. This isn't about extending the mt9v022 driver to work with non 
soc-camera hosts, it's about fixing soc-camera not to require any change to 
sensor drivers. Philipp, if you have time to work on that, we can discuss what 
needs to be done.

On the sensor side, we should have a single driver for the mt9v022, 024 and 
032 sensors. I would vote for merging the two drivers into 
drivers/media/i2c/mt9v032.c, as that one is closer to the goal of not being 
soc-camera specific.

-- 
Regards,

Laurent Pinchart