Re: [PATCH 2/2] iio: light: opt3001: enable operation w/o IRQ
From: Alexander Koch
Date: Tue Jan 12 2016 - 15:17:46 EST
Am 12.01.2016 um 20:27 schrieb Peter Meerwald-Stadler:
> On Tue, 12 Jan 2016, Alexander Koch wrote:
>
>> Enable operation of the TI OPT3001 light sensor without having an
>> interrupt line available to connect the INT pin to.
>>
>> In this operation mode, we issue a conversion request and simply wait
>> for the conversion time available as timeout value, determined from
>> integration time configuration and the worst-case time given in the data
>> sheet (sect. 6.5, table on p. 5):
>>
>> short integration time (100ms): 110ms + 3ms = 113ms
>> long integration time (800ms): 880ms + 3ms = 883ms
>>
>> This change is transparent as behaviour defaults to using the interrupt
>> method if an interrupt no. is configured via device tree. Interrupt-less
>> operation mode is performed when no valid interrupt no. is given.
>
> looks good, I'd rather use a bool for use_irq and the msecs_to_jiffies()
> call moved from the #define to the code (which is not strictly necessary
> for the patch) -- matter of taste
Thanks - actually this is my first patch, so positive feedback much
appreciated!
Concerning the bool for 'use_irq': I first had it that way but then
opted for the bit field of length 1 as I wasn't sure whether bool would
get optimized to the same level by the compiler.
I'm a bit irritated by your comment concerning the msecs_to_jiffies()
call, as my patch indeed moves this call from the #define to the code.
Did you mean it the other way round, then?
My reason to move it was that I need to work with microseconds for the
IRQ-less operation mode, and jiffies are only required in one place for
the IRQ mode.
Best regards
lynix