[PATCH v3 09/19] dt-bindings: nvmem: microchip-otpc: Add required clocks
Claudiu Beznea
claudiu.beznea at tuxon.dev
Sun Mar 8 09:42:49 PDT 2026
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
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