Hi Geert Uytterhoeven,
Thanks for the feedback.
> Subject: Re: [PATCH RFC 1/3] dt-bindings: clock: Add Renesas versa3 clock
> generator bindings
>
> Hi Krzysztof,
>
> On Thu, Mar 9, 2023 at 11:17 AM Krzysztof Kozlowski
> <krzysztof.kozlowski@xxxxxxxxxx> wrote:
> > On 09/03/2023 10:58, Geert Uytterhoeven wrote:
> > >>>>> Here it is, Please let me know is it ok?
> > >>>>>
> > >>>>> renesas,output-clock-fixed-rate-mode:
> > >>>>> type: boolean
> > >>>>> description:
> > >>>>> In output clock fixed rate mode, the output clock
> > >>>>> frequency is
> > >>>> always
> > >>>>> fixed and the hardware will use the values from the OTP or
> > >>>>> full
> > >>>> register
> > >>>>> map initialized during boot.
> > >>>>> If not given, the output clock rate is not fixed.
> > >>>>> maxItems: 6
> > >>>>
> > >>>> boolean is scalar, not array, so no maxItems. If the frequency is
> > >>>> taken from OTP or register map, why they cannot also provide
> > >>>> information the clock is fixed?
> > >>>
> > >>> OK, I will make an array property instead. From HW perspective
> > >>> each clock output from the Clock generator is controllable ie, fixed
> rate or dynamic rate.
> > >>>
> > >>> If all the output clocks are fixed rate one, then frequency is
> > >>> taken from OTP or register map. But if any one clock output
> > >>> generates dynamic rate, then it uses dynamic settings.
> > >>
> > >> Second try, same question, let me know if it is not clear:
> > >>
> > >> "why they cannot also provide information the clock is fixed?"
> > >
> > > What is the actual use case?
> > > My understanding is:
> > > 1. If the OTP is programmed, the clock generator will be configured
> > > from the OTP on power-on,
> > > 2. The clock generator can be (re)configured from software.
> > > a. If the OTP is programmed, this is not needed,
> > > b. For critical clocks, you may want to prevent this.
> > >
> > > Also, AFAIUI, "fixed frequency" or "dynamic frequency" is a policy,
> > > and purely software? Or are there OTP bits to enforce this?
> > >
> > > Perhaps you need a per-output "do-not-change-frequency" flag,
> > > probably with a generic name, in the spirit of "regulator-always-on"
> > > for regulators?
>
> Actually we already have "assigned-clock{,-rate}s" properties for that.
Actually it is a good pointer. I can make use of this property.
Cheers,
Biju
