Re: [PATCH 5/6] mx31moboard: camera support

[Valentin Longchamp <valentin.longchamp@epfl.ch>]

Hi Guennadi,

Valentin Longchamp wrote:
> Guennadi Liakhovetski wrote:
> 
>> 3. to support switching inputs, significant modifications to soc_camera.c 
>> would be required. I read Nate's argument before, that as long as clients 
>> can only be accessed one at a time, this should be presented by multiple 
>> inputs rather than multiple device nodes. Somebody else from the V4L folk 
>> has also confirmed this opinion. In principle I don't feel strongly either 
>> way. But currently soc-camera uses a one i2c client to one device node 
>> model, and I'm somewhat reluctant to change this before we're done with 
>> the v4l2-subdev conversion.
>>
> 
> Sure, one step at a time. So for now the switching is not possible with 
> soc_camera.
> 
> My problem is that both cameras have the same I2C address since they are 
> the same.
> 
> Would I need to declare 2 i2c_device with the same address (I'm not sure 
> it would even work ...) used by two _client_ platform_devices or would I 
> have to have the two platform devices pointing to the same i2c_device ?
> 

I've finally had time to test all this. My current problem with 
registering the two cameras is that they both have the same i2c address, 
and soc_camera calls v4l2_i2c_new_subdev_board where in my case the same 
address on the same i2c tries to be registered and of course fails.

We would need a way in soc_camera not to register a new i2c client for 
device but use an existing one (but that's what you don't want to change 
for now as you state it in your above last sentence). I just want to 
point this out once more so that you know there is interest about this 
for the next soc_camera works.

So my current solution for mainline inclusion is to register only one 
camera device node without taking care of the cam mux for now.

Val

-- 
Valentin Longchamp, PhD Student, EPFL-STI-LSRO1
valentin.longchamp@epfl.ch, Phone: +41216937827
http://people.epfl.ch/valentin.longchamp
MEA3485, Station 9, CH-1015 Lausanne