Re: [PATCH v3 09/19] dt-bindings: nvmem: microchip-otpc: Add required clocks

[Claudiu Beznea]

+ Alexander Dahl

On 3/8/26 18:42, Claudiu Beznea wrote:
> Hi, Alexander,
>
> On 2/20/26 11:58, Alexander Dahl wrote:
> > Hello Claudiu,
> >
> > Am Sat, Jan 31, 2026 at 05:47:05PM +0200 schrieb Claudiu Beznea:
> > > On 1/20/26 17:44, Alexander Dahl wrote:
> > > > The OTPC requires both the peripheral clock through PMC and the main RC
> > > > oscillator.  Seemed to work without explicitly enabling those clocks on
> > > > sama7g5 before, but did not on sam9x60.
> > > >
> > > > Older datasheets were not clear and explicit about this, but recent are,
> > > > e.g. SAMA7G5 series datasheet (DS60001765B),
> > > > section 30.4.1 Power Management:
> > > >
> > > > > The OTPC is clocked through the Power Management Controller (PMC).
> > > > > The user must power on the main RC oscillator and enable the
> > > > > peripheral clock of the OTPC prior to reading or writing the OTP
> > > > > memory.
> > >
> > > As this was not mentioned in the previous datasheet versions, the current
> > > driver don't handle those clocks, and it probably worked as the clocks were
> > > enabled by bootloaders, I think the clocks should be marked as required and
> > > this patch to be propagated as a fix along with fixes on driver and device
> > > trees.
> >
> > What do you mean by "clocks should be marked as required"?  Where?
>
> In the bindings as you found that the IP don't work if the clocks are not enabled?
>
> > How?  Is something more necessary, than already done here?
>
> Update the required section in the yaml file with clocks, at least for the 
> sam9x60, as you found it is not working w/o it.
>
> I presume it has to be done for SAMA7G5 as well (as this is what the newer 
> datasheets states) but that would involve adding required clocks now which were 
> not needed later. I'm not sure what is the procedure here. I'll let DT 
> maintainers comment on this.
>
> Thank you,
> Claudiu