Re: [PATCH] leds: leds-pca963x: workaround group blink scaling issue
From: Tony Lindgren
Date: Fri Oct 14 2016 - 10:21:03 EST
* Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx> [161013 23:37]:
> On 10/13/2016 04:20 PM, Matt Ranostay wrote:
> > On Thu, Oct 13, 2016 at 4:05 PM, Jacek Anaszewski
> > <j.anaszewski@xxxxxxxxxxx> wrote:
> > > Why DT property? Is it somehow dependent on the board configuration?
> > > How this period-scale value is calculated? Is it inferred empirically?
> > >
> > We empirically discovered and verified this with an logic analyzer on
> > multiple batches of this part.
> > Reason for the DT entry is we aren't 100% sure that it is always going
> > to be the same with different board revs.
> > Could be that parts clock acts differently with supply voltage. This
> > has been calculated by setting it an expected value, and measuring the
> > actual result with the logic analyzer.
> I'd like to have DT maintainer's ack for this.
> Cc Rob and Mark.
How about do this based on the compatible property instead? If there
are multiple manufacturers for this part and only a certain
parts have this issue we should have multiple compatible properties.
Then if it turns out all of them need this scaling there's no need
to update the binding.