[PATCH 4/6] dt-bindings: clock: st,stm32-rcc: support spread spectrum clocking

[Dario Binacchi <dario.binacchi@amarulasolutions.com>]

The addition of DT bindings for enabling and tuning spread spectrum
clocking generation is available only for the main PLL.

Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
---

 .../bindings/clock/st,stm32-rcc.yaml          | 27 +++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/Documentation/devicetree/bindings/clock/st,stm32-rcc.yaml b/Documentation/devicetree/bindings/clock/st,stm32-rcc.yaml
index ae9e5b26d876..c345d3ff3fc4 100644
--- a/Documentation/devicetree/bindings/clock/st,stm32-rcc.yaml
+++ b/Documentation/devicetree/bindings/clock/st,stm32-rcc.yaml
@@ -77,6 +77,26 @@ 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/non-unique-string-array
+    description:
+      The modulation techniques for main PLL.
+    items:
+      enum:
+        - center-spread
+        - down-spread
+
 required:
   - compatible
   - reg
@@ -97,6 +117,10 @@ allOf:
           const: 1
           description: |
             The clock index for the specified type.
+        st,ssc-modfreq-hz: false
+        st,ssc-moddepth-permyriad: false
+        st,ssc-modmethod: false
+
     else:
       properties:
         '#clock-cells':
@@ -118,6 +142,9 @@ examples:
         reg = <0x40023800 0x400>;
         clocks = <&clk_hse>, <&clk_i2s_ckin>;
         st,syscfg = <&pwrcfg>;
+        st,ssc-modfreq-hz = <10000>;
+        st,ssc-moddepth-permyriad = <200>;
+        st,ssc-modmethod = "center-spread";
     };
 
   - |
-- 
2.43.0