Re: [RFC 16/17] smiapp: Add driver.

[Sylwester Nawrocki <snjw23@gmail.com>]

Hi Sakari,

On 01/08/2012 12:01 AM, Sakari Ailus wrote:
>>> +/*
>>> + *
>>> + * V4L2 Controls handling
>>> + *
>>> + */
>>> +
>>> +static void __smiapp_update_exposure_limits(struct smiapp_sensor *sensor)
>>> +{
>>> +	struct v4l2_ctrl *ctrl = sensor->exposure;
>>> +	int max;
>>> +
>>> +	max = sensor->pixel_array->compose[SMIAPP_PAD_SOURCE].height
>>> +		+ sensor->vblank->val -
>>> +		sensor->limits[SMIAPP_LIMIT_COARSE_INTEGRATION_TIME_MAX_MARGIN];
>>> +
>>> +	ctrl->maximum = max;
>>> +	if (ctrl->default_value>   max)
>>> +		ctrl->default_value = max;
>>> +	if (ctrl->val>   max)
>>> +		ctrl->val = max;
>>> +	if (ctrl->cur.val>   max)
>>> +		ctrl->cur.val = max;
>>> +}
>>
>> One more driver that needs control value range update. :)
> 
> :-)
> 
> Are there other drivers that would need something like that, too?
> Anything in the control framework that I have missed related to this?

Yes, I needed that in s5p-fimc driver for the alpha component control.
The alpha channel value range depends on colour format and the control 
needs to be updated accordingly to changes done with VIDIOC_S_FMT.

And no, there is yet nothing in the control framework to support this.
Hans just prepared some proof-of-concept patch [1], but the decision was
to hold on until there appear more drivers needing control value range
update, due to hight complication of life in the userland.

[1] http://www.mail-archive.com/linux-media@vger.kernel.org/msg39674.html

--
Regards,
Sylwester