Re: [PATCH v2 2/4] dt-bindings: ti: dpll: add spread spectrum support

From: Rob Herring
Date: Thu Mar 25 2021 - 21:19:16 EST


On Thu, Mar 18, 2021 at 06:26:24PM +0100, Dario Binacchi wrote:
> DT bindings for enabling and adjusting spread spectrum clocking have
> been added.
>
> Signed-off-by: Dario Binacchi <dariobin@xxxxxxxxx>
> ---
>
> (no changes since v1)
>
> .../devicetree/bindings/clock/ti/dpll.txt | 20 +++++++++++++++++++
> 1 file changed, 20 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/clock/ti/dpll.txt b/Documentation/devicetree/bindings/clock/ti/dpll.txt
> index df57009ff8e7..0810ae073294 100644
> --- a/Documentation/devicetree/bindings/clock/ti/dpll.txt
> +++ b/Documentation/devicetree/bindings/clock/ti/dpll.txt
> @@ -42,6 +42,11 @@ Required properties:
> "idlest" - contains the idle status register base address
> "mult-div1" - contains the multiplier / divider register base address
> "autoidle" - contains the autoidle register base address (optional)
> + "ssc-deltam" - DPLL supports spread spectrum clocking (SSC), contains
> + the frequency spreading register base address (optional)
> + "ssc-modfreq" - DPLL supports spread spectrum clocking (SSC), contains
> + the modulation frequency register base address
> + (optional)
> ti,am3-* dpll types do not have autoidle register
> ti,omap2-* dpll type does not support idlest / autoidle registers
>
> @@ -51,6 +56,14 @@ Optional properties:
> - ti,low-power-stop : DPLL supports low power stop mode, gating output
> - ti,low-power-bypass : DPLL output matches rate of parent bypass clock
> - ti,lock : DPLL locks in programmed rate
> + - ti,min-div : the minimum divisor to start from to round the DPLL
> + target rate
> + - ti,ssc-deltam : DPLL supports spread spectrum clocking, frequency
> + spreading in permille (10th of a percent)
> + - ti,ssc-modfreq : DPLL supports spread spectrum clocking, spread
> + spectrum modulation frequency in kHz

Use a standard unit suffix (-hz or -mhz).

> + - ti,ssc-downspread : DPLL supports spread spectrum clocking, boolean
> + to enable the downspread feature
>
> Examples:
> dpll_core_ck: dpll_core_ck@44e00490 {
> @@ -83,3 +96,10 @@ Examples:
> clocks = <&sys_ck>, <&sys_ck>;
> reg = <0x0500>, <0x0540>;
> };
> +
> + dpll_disp_ck: dpll_disp_ck {
> + #clock-cells = <0>;
> + compatible = "ti,am3-dpll-no-gate-clock";
> + clocks = <&sys_clkin_ck>, <&sys_clkin_ck>;
> + reg = <0x0498>, <0x0448>, <0x0454>, <0x044c>, <0x0450>;
> + };
> --
> 2.17.1
>