Re: as3645a flash userland interface

[Sylwester Nawrocki <s.nawrocki-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>]

Hi,

On 09/13/2017 07:53 PM, Jacek Anaszewski wrote:
> On 09/12/2017 11:55 PM, Pavel Machek wrote:
>> On Tue 2017-09-12 20:53:33, Jacek Anaszewski wrote:
>>> On 09/12/2017 12:36 PM, Pavel Machek wrote:

>>>> What directory are the flash controls in?
>>>>
>>>> /sys/class/leds/led-controller:flash ?
>>>>
>>>> Could we arrange for something less generic, like
>>>>
>>>> /sys/class/leds/main-camera:flash ?
>>>
>>> I'd rather avoid overcomplicating this. LED class device name pattern
>>> is well defined to devicename:colour:function
>>> (see Documentation/leds/leds-class.txt, "LED Device Naming" section).
>>>
>>> In this case "flash" in place of the "function" segment makes the
>>> things clear enough I suppose.
>>
>> It does not.
>>
>> Phones usually have two cameras, front and back, and these days both
>> cameras have their flash.
>>
>> And poor userspace flashlight application can not know if as3645
>> drivers front LED or back LED. Thus, I'd set devicename to
>> front-camera or main-camera -- because that's what it is associated
>> with. Userspace does not care what hardware drives the LED, but needs
>> to know if it is front or back camera.
> 
> The name of a LED flash class device isn't fixed and is derived
> from DT label property. Name in the example of some DT bindings
> will not force people to apply similar pattern for the other
> drivers and even for the related one. No worry about having
> to keep anything forever basing on that.

Isn't the V4L2 subdev/Media Controller API supposed to provide means
for associating flash LEDs with camera sensors? You seem to be insisting
on using the sysfs leds interface for that, which is not a primary
interface for camera flash AFAICT.

-- 
Regards,
Sylwester
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