| Message ID | 20250118124044.157308-17-dario.binacchi@amarulasolutions.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Support spread spectrum clocking for i.MX8M PLLs | expand |
On 18/01/2025 13:39, Dario Binacchi wrote: > The addition of DT bindings for enabling and tuning spread spectrum > clocking generation can be applied specifically to the PLLs. > > The "" value for the fsl,ssc-method property is specifically intended to > specify a "no SSC" case, as in the example, when you don't want to > configure spread spectrum for one of the PLLs, thus avoiding the use of > a method that would only make sense if SSC were being set. > > Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com> > Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> > > --- > > (no changes since v7) > > Changes in v7: > - List the PLLs to strictly define the setup order for each of the > added properties > - Drop maxItems from "fsl,ssc-modfreq-hz" and "fsl,ssc-modrate-percent" > properties > - Add 'Reviewed-by' tag of Krzysztof Kozlowski > > Changes in v6: > - Improve the commit message > - change minItems from 7 to 1 for all the ssc properties added > - change maxItems from 10 to 4 for alle the ssc properties added > - update the DTS example > > Changes in v4: > - Drop "fsl,ssc-clocks" property. The other added properties now refer > to the clock list. > - Updated minItems and maxItems of > - clocks > - clock-names > - fsl,ssc-modfreq-hz > - fsl,ssc-modrate-percent > - fsl,ssc-modmethod > - Updated the dts examples > > Changes in v3: > - Added in v3 > - The dt-bindings have been moved from fsl,imx8m-anatop.yaml to > imx8m-clock.yaml. The anatop device (fsl,imx8m-anatop.yaml) is > indeed more or less a syscon, so it represents a memory area > accessible by ccm (imx8m-clock.yaml) to setup the PLLs. > > Changes in v2: > - Add "allOf:" and place it after "required:" block, like in the > example schema. > - Move the properties definition to the top-level. > - Drop unit types as requested by the "make dt_binding_check" command. > > .../bindings/clock/imx8m-clock.yaml | 47 +++++++++++++++++++ > 1 file changed, 47 insertions(+) > > diff --git a/Documentation/devicetree/bindings/clock/imx8m-clock.yaml b/Documentation/devicetree/bindings/clock/imx8m-clock.yaml > index d96570bf60dc..d347d630764a 100644 > --- a/Documentation/devicetree/bindings/clock/imx8m-clock.yaml > +++ b/Documentation/devicetree/bindings/clock/imx8m-clock.yaml > @@ -43,6 +43,46 @@ properties: > ID in its "clocks" phandle cell. See include/dt-bindings/clock/imx8m-clock.h > for the full list of i.MX8M clock IDs. > > + fsl,ssc-modfreq-hz: > + description: > + The values of modulation frequency (Hz unit) for each clock > + supporting spread spectrum. > + minItems: 1 > + items: > + - description: audio_pll1 > + - description: audio_pll2 > + - description: dram_pll > + - description: video_pll Ehh, so it looks that nine versions of this patches for iMX8 and NXP comes with generic bindings for iMX9. Better late than never, but a pity that they did not share the intention, which would spare you effort. Please work with Peng and unify approach for entire iMX and use common bindings. https://github.com/devicetree-org/dt-schema/pull/154 Best regards, Krzysztof
diff --git a/Documentation/devicetree/bindings/clock/imx8m-clock.yaml b/Documentation/devicetree/bindings/clock/imx8m-clock.yaml index d96570bf60dc..d347d630764a 100644 --- a/Documentation/devicetree/bindings/clock/imx8m-clock.yaml +++ b/Documentation/devicetree/bindings/clock/imx8m-clock.yaml @@ -43,6 +43,46 @@ properties: ID in its "clocks" phandle cell. See include/dt-bindings/clock/imx8m-clock.h for the full list of i.MX8M clock IDs. + fsl,ssc-modfreq-hz: + description: + The values of modulation frequency (Hz unit) for each clock + supporting spread spectrum. + minItems: 1 + items: + - description: audio_pll1 + - description: audio_pll2 + - description: dram_pll + - description: video_pll + + fsl,ssc-modrate-percent: + description: + The percentage values of modulation rate for each clock + supporting spread spectrum. + minItems: 1 + items: + - description: audio_pll1 + - description: audio_pll2 + - description: dram_pll + - description: video_pll + + fsl,ssc-modmethod: + $ref: /schemas/types.yaml#/definitions/non-unique-string-array + description: | + The modulation techniques for each clock supporting spread + spectrum in this order:: + - audio_pll1 + - audio_pll2 + - dram_pll + - video_pll + minItems: 1 + maxItems: 4 + items: + enum: + - "" + - down-spread + - up-spread + - center-spread + required: - compatible - reg @@ -76,6 +116,10 @@ allOf: - const: clk_ext2 - const: clk_ext3 - const: clk_ext4 + fsl,ssc-modfreq-hz: false + fsl,ssc-modrate-percent: false + fsl,ssc-modmethod: false + else: properties: clocks: @@ -124,6 +168,9 @@ examples: clock-names = "osc_32k", "osc_24m", "clk_ext1", "clk_ext2", "clk_ext3", "clk_ext4", "audio_pll1", "audio_pll2", "dram_pll", "video_pll"; + fsl,ssc-modfreq-hz = <6818>, <0>, <0>, <2419>; + fsl,ssc-modrate-percent = <3>, <0>, <0>, <7>; + fsl,ssc-modmethod = "down-spread", "", "", "center-spread"; }; - |