Re: [PATCH v3] DT: Add documentation for the mfd Maxim max77693

Jacek Anaszewski
2015-03-30T13:46:38Z

Hi Mark,

On 03/30/2015 03:20 PM, Mark Rutland wrote:
> Hi,
>
>>>> +Optional properties:
>>>> +- maxim,trigger-type : Flash trigger type.
>>>> + Possible trigger types:
>>>> + LEDS_TRIG_TYPE_EDGE (0) - Rising edge of the signal triggers
>>>> + the flash,
>>>> + LEDS_TRIG_TYPE_LEVEL (1) - Strobe pulse length controls duration
>>>> + of the flash.
>>>
>>> Surely this is required? What should be assumed if this property isn't
>>> present?
>>
>> LEDS_TRIG_TYPE_LEVEL allows for an ISP to do e.g. short flash blink
>> before the actual strobe - it is used for eliminating photographs with
>> closed eyes, or can serve for probing ambient light conditions.
>>
>> With LEDS_TRIG_TYPE_EDGE flash strobe is triggered on rising edge
>> and lasts until programmed timeout expires.
>>
>> This setting is tightly related to a camera sensor, which generates
>> the strobe signal. Effectively it depends on board configuration.
>
> My comment wasn't to do with the semantics of eitehr option but rather
> the optionality of the property.
>
> Surely it's vital to know what this should be, and hence this property
> should be required rather than optional?
>
> If it isn't required, what would the assumed default be?

Default is LEDS_TRIG_TYPE_EDGE.

--
Best Regards,
Jacek Anaszewski