Re: [PATCH v2 1/2] dt: bindings: lm3697: Add bindings for lm3697 driver

From: Pavel Machek
Date: Wed Aug 08 2018 - 17:09:31 EST


On Wed 2018-08-08 16:04:43, Dan Murphy wrote:
> On 08/08/2018 04:02 PM, Pavel Machek wrote:
> > Hi!
> >
> >>>> + - #size-cells : 0
> >>>> + - control-bank-cfg - : Indicates which sink is connected to which control bank
> >>>> + 0 - All HVLED outputs are controlled by bank A
> >>>> + 1 - HVLED1 is controlled bank B, HVLED2/3 are controlled by bank A
> >>>> + 2 - HVLED2 is controlled bank B, HVLED1/3 are controlled by bank A
> >>>> + 3 - HVLED1/2 are controlled by bank B, HVLED3 is controlled by bank A
> >>>> + 4 - HVLED3 is controlled by bank B, HVLED1/2 are controlled by bank A
> >>>> + 5 - HVLED1/3 is controlled by bank B, HVLED2 is controlled by bank A
> >>>> + 6 - (default) HVLED1 is controlled by bank A, HVLED2/3 are controlled by bank B
> >>>> + 7 - All HVLED outputs are controlled by bank B
> >>>
> >>> This is quite long way to describe a bitmask, no? Could we make
> >>> it so that control-bank-cfg is not needed?
> >>
> >> The problem we have here is there is a potential to control
> >> 3 different LED string but only 2 sinks. So control bank A can control 2 LED strings and control
> >> bank b can control 1 LED string.
> >>
> >
> > Can we forget about the LED strings, and just expose the sinks as
> > Linux LED devices?
>
> 2 sinks 3 LED strings. How do you know which LED string is which and what bank it belongs
> to when setting the brightness. Each Bank has a separate register for brightness control.

Yes, and LED strings are statically assigned to banks, right?

So why not simply forget about LED strings for sake of hw
abstractions, and work just with banks?
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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