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

From: Dan Murphy
Date: Wed Aug 08 2018 - 17:05:02 EST


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.

Dan

> Pavel
>


--
------------------
Dan Murphy