@@ -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(+)