| Message ID | 20241222170534.3621453-17-dario.binacchi@amarulasolutions.com |
|---|---|
| State | New |
| Headers | show |
| Series |
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| Related | show |
On Sun, Dec 22, 2024 at 06:04:31PM +0100, 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> > > --- > > 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 | 38 +++++++++++++++++++ > 1 file changed, 38 insertions(+) > > diff --git a/Documentation/devicetree/bindings/clock/imx8m-clock.yaml b/Documentation/devicetree/bindings/clock/imx8m-clock.yaml > index 05bc01960045..37cc6a6e89d4 100644 > --- a/Documentation/devicetree/bindings/clock/imx8m-clock.yaml > +++ b/Documentation/devicetree/bindings/clock/imx8m-clock.yaml > @@ -43,6 +43,37 @@ 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 (i. e. audio_pll1, audio_pll2, > + dram_pll and video_pll). > + minItems: 1 > + maxItems: 4 Please list the items. You rely here on this being in strict order, so this should be explicit, instead of just "in example" in the description. items: - description: audio_pll1 > + > + fsl,ssc-modrate-percent: > + description: > + The percentage values of modulation rate for each clock > + supporting spread spectrum (i. e. audio_pll1, audio_pll2, > + dram_pll and video_pll). > + minItems: 1 > + maxItems: 4 Ditto > + > + fsl,ssc-modmethod: > + $ref: /schemas/types.yaml#/definitions/non-unique-string-array > + description: > + The modulation techniques for each clock supporting spread > + spectrum (i. e. audio_pll1, audio_pll2, dram_pll and > + video_pll). I guess here listing items might not work, so: The modulation techniques for each clock supporting spread spectrum, in this order: audio_pll1, audio_pll2, dram_pll and video_pll Everything looks good for me, so with above changes: Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> Best regards, Krzysztof To unsubscribe from this group and stop receiving emails from it, send an email to linux-amarula+unsubscribe@amarulasolutions.com.
diff --git a/Documentation/devicetree/bindings/clock/imx8m-clock.yaml b/Documentation/devicetree/bindings/clock/imx8m-clock.yaml index 05bc01960045..37cc6a6e89d4 100644 --- a/Documentation/devicetree/bindings/clock/imx8m-clock.yaml +++ b/Documentation/devicetree/bindings/clock/imx8m-clock.yaml @@ -43,6 +43,37 @@ 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 (i. e. audio_pll1, audio_pll2, + dram_pll and video_pll). + minItems: 1 + maxItems: 4 + + fsl,ssc-modrate-percent: + description: + The percentage values of modulation rate for each clock + supporting spread spectrum (i. e. audio_pll1, audio_pll2, + dram_pll and video_pll). + minItems: 1 + maxItems: 4 + + fsl,ssc-modmethod: + $ref: /schemas/types.yaml#/definitions/non-unique-string-array + description: + The modulation techniques for each clock supporting spread + spectrum (i. e. audio_pll1, audio_pll2, dram_pll and + video_pll). + minItems: 1 + maxItems: 4 + items: + enum: + - "" + - down-spread + - up-spread + - center-spread + required: - compatible - reg @@ -76,6 +107,10 @@ 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 +159,9 @@ 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"; }; - |
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> --- 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 | 38 +++++++++++++++++++ 1 file changed, 38 insertions(+)