Commit 223d32eb authored by Dario Binacchi's avatar Dario Binacchi Committed by Stephen Boyd
Browse files

dt-bindings: clock: st,stm32-rcc: support spread spectrum clocking 



The addition of DT bindings for enabling and tuning spread spectrum
clocking generation is available only for the main PLL of stm32f{4,7}
platforms.

Signed-off-by: default avatarDario Binacchi <dario.binacchi@amarulasolutions.com>
Reviewed-by: default avatarKrzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Link: https://lore.kernel.org/r/20250114182021.670435-3-dario.binacchi@amarulasolutions.com


Signed-off-by: default avatarStephen Boyd <sboyd@kernel.org>
parent ebca3970

Documentation/devicetree/bindings/clock/st,stm32-rcc.yaml

+36 −0
Original line number Diff line number Diff line
@@ -53,6 +53,26 @@ properties: 
      Phandle to system configuration controller. It can be used to control the

      power domain circuitry.



  st,ssc-modfreq-hz:

    description:

      The modulation frequency for main PLL (in Hz)



  st,ssc-moddepth-permyriad:

    $ref: /schemas/types.yaml#/definitions/uint32

    description:

      The modulation rate for main PLL (in permyriad, i.e. 0.01%)

    minimum: 25

    maximum: 200



  st,ssc-modmethod:

    $ref: /schemas/types.yaml#/definitions/string

    description:

      The modulation techniques for main PLL.

    items:

      enum:

        - center-spread

        - down-spread



required:

  - compatible

  - reg
@@ -78,6 +98,10 @@ allOf: 
            - description: high speed external (HSE) clock input

            - description: low speed external (LSE) clock input

            - description: Inter-IC sound (I2S) clock input

        st,ssc-modfreq-hz: false

        st,ssc-moddepth-permyriad: false

        st,ssc-modmethod: false



    else:

      properties:

        '#clock-cells':
@@ -95,6 +119,18 @@ additionalProperties: false 


examples:

  # Reset and Clock Control Module node:

  - |

    clock-controller@40023800 {

        compatible = "st,stm32f42xx-rcc", "st,stm32-rcc";

        reg = <0x40023800 0x400>;

        #clock-cells = <2>;

        #reset-cells = <1>;

        clocks = <&clk_hse>, <&clk_i2s_ckin>;

        st,syscfg = <&pwrcfg>;

        st,ssc-modfreq-hz = <10000>;

        st,ssc-moddepth-permyriad = <200>;

        st,ssc-modmethod = "center-spread";

    };

  - |

    clock-controller@58024400 {

        compatible = "st,stm32h743-rcc", "st,stm32-rcc";