Re: Control Register device tree binding request for Opt3001

[Jonathan Cameron <Jonathan.Cameron@Huawei.com>]

On Thu, 18 Feb 2021 10:35:27 +0200
Alexandru Ardelean <ardeleanalex@gmail.com> wrote:

> On Thu, Feb 18, 2021 at 7:27 AM Ekin Böke <ekin_boke@arcelik.com> wrote:
> >
> > Hi,
> >
> > We are using Opt3001 for a day light control system and according to the data sheet it has 2 conversion time modes
> > that are 100 ms(CT=0) and 800 ms(CT=1) . Configuration register field CT controls the conversion time and we want to set the CT parameter at the initialization to 0 at all times. We could do it by using the in_illuminance_integration_time sysfs node at the runtime.
> >
> > Should we add a parameter to the device tree bindings or is there another way to set the CT parameter at the initialization?  
> 
> It's usually a good idea to use the sysfs attribute, if it's already available.
> Maybe during system boot-up, you can add some service init call to
> initialize to 100 ms or right before starting to read data from the
> sensor.
> 
> For kernel people, these initialization device-tree attributes seem convenient.
> But in this case, CT is a parameter of the chip and not a hard-wired
> configuration of the board [which needs to be described in DT].

As described, what you want to control here is policy, not a characteristic
of the hardware.   Normally we don't use DT to make such decisions, as it should
be controlled at runtime.

So basically what Alex said :)

Jonathan

> 
> >
> >
> > Best Regards
> >
> > Ekin
> >
> >
> >
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