Re: [PATCH v2 08/16] dt-bindings: nvmem: microchip-otpc: Add required clocks

Krzysztof Kozlowski
2025-02-10T16:59:58Z

On 10/02/2025 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.
>
> Link: https://lore.kernel.org/linux-clk/ec34efc2-2051-4b8a-b5d8-6e2fd5e08c28@microchip.com/T/#u
> Signed-off-by: Alexander Dahl <ada@thorsis.com>
> ---
>
> Notes:
> v2:
> - new patch, not present in v1
>
> .../nvmem/microchip,sama7g5-otpc.yaml | 28 +++++++++++++++++++
> 1 file changed, 28 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/nvmem/microchip,sama7g5-otpc.yaml b/Documentation/devicetree/bindings/nvmem/microchip,sama7g5-otpc.yaml
> index 9a7aaf64eef32..1fa40610888f3 100644
> --- a/Documentation/devicetree/bindings/nvmem/microchip,sama7g5-otpc.yaml
> +++ b/Documentation/devicetree/bindings/nvmem/microchip,sama7g5-otpc.yaml
> @@ -29,6 +29,16 @@ properties:
> reg:
> maxItems: 1
>
> + clocks:
> + items:
> + - description: main rc oscillator
> + - description: otpc peripheral clock
> +
> + clock-names:
> + items:
> + - const: main_rc_osc

osc

> + - const: otpc_clk

otpc or bus or whatever logically this is

> +
> required:
> - compatible
> - reg
> @@ -37,6 +47,8 @@ unevaluatedProperties: false
>
> examples:
> - |
> + #include <dt-bindings/clock/at91.h>
> + #include <dt-bindings/clock/microchip,sama7g5-pmc.h>
> #include <dt-bindings/nvmem/microchip,sama7g5-otpc.h>
>
> otpc: efuse@e8c00000 {
> @@ -44,10 +56,26 @@ examples:
> reg = <0xe8c00000 0xec>;
> #address-cells = <1>;
> #size-cells = <1>;
> + clocks = <&pmc PMC_TYPE_CORE SAMA7G5_PMC_MAIN_RC>, <&pmc PMC_TYPE_PERIPHERAL 67>;
> + clock-names = "main_rc_osc", "otpc_clk";
>
> temperature_calib: calib@1 {
> reg = <OTP_PKT(1) 76>;
> };
> };
>
> + - |
> + #include <dt-bindings/clock/at91.h>
> + #include <dt-bindings/clock/microchip,sam9x60-pmc.h>
> + #include <dt-bindings/nvmem/microchip,sama7g5-otpc.h>
> +
> + efuse@eff00000 {
> + compatible = "microchip,sam9x60-otpc", "syscon";
> + reg = <0xeff00000 0xec>;

No need for new example with difference in what exactly? Even compatible
was not added here...

> + #address-cells = <1>;
> + #size-cells = <1>;
> + clocks = <&pmc PMC_TYPE_CORE SAM9X60_PMC_MAIN_RC>, <&pmc PMC_TYPE_PERIPHERAL 46>;
> + clock-names = "main_rc_osc", "otpc_clk";
> + };
> +
> ...

Best regards,
Krzysztof