New v4l2 driver does not allow brightness/contrast control

New v4l2 driver does not allow brightness/contrast control

[Rafael Coutinho]

I have a v4l2 video capture board that using kernel 2.6 with v4l2
em28xx driver 3.0.36 allows me to control brightness, contrast etc...
However in kernel 3.2 with v4l2 em28xx driver version 3.2.0 it does not.

This is what I get from the latest driver:
root@android:/ # v4l2-ctl --info
Driver Info (not using libv4l2):
Driver name   : em28xx
Card type     : EM2860/SAA711X Reference Design
Bus info      : usb-musb-hdrc.1-1
Driver version: 3.2.0
Capabilities  : 0x05020051
Video Capture
VBI Capture
Sliced VBI Capture
Audio
Read/Write
Streaming
root@android:/ # v4l2-ctl  -d 0 -l
                         volume (int)    : min=0 max=31 step=1
default=31 value=31 flags=slider
                           mute (bool)   : default=1 value=1


What could be wrong?

-- 
Atenciosamente,
Coutinho

Re: New v4l2 driver does not allow brightness/contrast control

[Frank Schäfer]

Am 07.07.2014 19:58, schrieb Rafael Coutinho:
> I have a v4l2 video capture board that using kernel 2.6 with v4l2
> em28xx driver 3.0.36 allows me to control brightness, contrast etc...
> However in kernel 3.2 with v4l2 em28xx driver version 3.2.0 it does not.
>
> This is what I get from the latest driver:
> root@android:/ # v4l2-ctl --info
> Driver Info (not using libv4l2):
> Driver name   : em28xx
> Card type     : EM2860/SAA711X Reference Design
> Bus info      : usb-musb-hdrc.1-1
> Driver version: 3.2.0
> Capabilities  : 0x05020051
> Video Capture
> VBI Capture
> Sliced VBI Capture
> Audio
> Read/Write
> Streaming
> root@android:/ # v4l2-ctl  -d 0 -l
>                          volume (int)    : min=0 max=31 step=1
> default=31 value=31 flags=slider
>                            mute (bool)   : default=1 value=1
>
>
> What could be wrong?

Before kernel 3.10, the brightness (contrast, ...) controls are provided
by the subdevice drivers.
With kernel 3.10 I have introduced bridge level image controls, but they
are currently only used/activated if the subdevice doesn't already
provide them (as suggested by Mauro).

Hth,
Frank Schäfer

Re: New v4l2 driver does not allow brightness/contrast control

[Rafael Coutinho]

Yeah, tested on kernel 3.15 and it worked. The problem is that my
board doesn't have Android  HAL's compatible with that version, so i'm
trying to find where is the difference.

2014-07-08 15:10 GMT-03:00 Frank Schäfer <fschaefer.oss@googlemail.com>:
>
> Am 07.07.2014 19:58, schrieb Rafael Coutinho:
>> I have a v4l2 video capture board that using kernel 2.6 with v4l2
>> em28xx driver 3.0.36 allows me to control brightness, contrast etc...
>> However in kernel 3.2 with v4l2 em28xx driver version 3.2.0 it does not.
>>
>> This is what I get from the latest driver:
>> root@android:/ # v4l2-ctl --info
>> Driver Info (not using libv4l2):
>> Driver name   : em28xx
>> Card type     : EM2860/SAA711X Reference Design
>> Bus info      : usb-musb-hdrc.1-1
>> Driver version: 3.2.0
>> Capabilities  : 0x05020051
>> Video Capture
>> VBI Capture
>> Sliced VBI Capture
>> Audio
>> Read/Write
>> Streaming
>> root@android:/ # v4l2-ctl  -d 0 -l
>>                          volume (int)    : min=0 max=31 step=1
>> default=31 value=31 flags=slider
>>                            mute (bool)   : default=1 value=1
>>
>>
>> What could be wrong?
>
> Before kernel 3.10, the brightness (contrast, ...) controls are provided
> by the subdevice drivers.
> With kernel 3.10 I have introduced bridge level image controls, but they
> are currently only used/activated if the subdevice doesn't already
> provide them (as suggested by Mauro).
>
> Hth,
> Frank Schäfer
>



-- 
Regards,
Coutinho
www.phiinnovations.com