[PATCH v3 1/8] dt-bindings: clock: clocking-wizard: Add static-config mode support

Shubhrajyoti Datta <[email protected]> Fri, 31 Jul 2026 12:50:42 +0530
Newsgroups org.kernel.vger.linux-clk,org.infradead.lists.linux-arm-kernel,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-kernel
Message-ID <[email protected]>
Static-config MMCM/PLL ratios are fixed at IP build time, so the kernel
cannot read per-output multiply/divide from registers and needs DT pairs
to register fixed-factor clocks. Also add the tuples by pair in example.

In static-config mode the IP exposes only fixed-factor clock outputs and
has no runtime-programmable registers, so reg is not required.
Make reg optional for static-config

In static-config mode the AXI bus interface is unused, so s_axi_aclk
is not required. Allow clocks/clock-names to have only one entry
(clk_in1) when xlnx,static-config is present and enforce two entries
otherwise. Update the static-config example accordingly.

Reviewed-by: Rob Herring (Arm) <[email protected]>
Signed-off-by: Shubhrajyoti Datta <[email protected]>
---

Changes in v3:
Added reviewed tag

Changes in v2:
Merged the similar patches
Allow check for current dt even if it is unused.

 .../bindings/clock/xlnx,clocking-wizard.yaml  | 53 +++++++++++++++++--
 1 file changed, 48 insertions(+), 5 deletions(-)

diff --git a/Documentation/devicetree/bindings/clock/xlnx,clocking-wizard.yaml b/Documentation/devicetree/bindings/clock/xlnx,clocking-wizard.yaml
index b497c28e8094..865927b9f1be 100644
--- a/Documentation/devicetree/bindings/clock/xlnx,clocking-wizard.yaml
+++ b/Documentation/devicetree/bindings/clock/xlnx,clocking-wizard.yaml
@@ -29,11 +29,13 @@ properties:
     const: 1
 
   clocks:
+    minItems: 1
     items:
       - description: clock input
       - description: axi clock
 
   clock-names:
+    minItems: 1
     items:
       - const: clk_in1
       - const: s_axi_aclk
@@ -57,27 +59,68 @@ properties:
     description:
       Number of outputs.
 
+  xlnx,clk-mul-div:
+    $ref: /schemas/types.yaml#/definitions/uint32-matrix
+    description:
+      Fixed MMCM/PLL multiply/divide ratios, one (multiplier, divisor)
+      pair per clock output relative to clk_in1. The number of entries
+      must equal xlnx,nr-outputs.
+    minItems: 1
+    maxItems: 8
+    items:
+      items:
+        - description: multiplier
+          minimum: 1
+        - description: divisor
+          minimum: 1
+
 required:
   - compatible
-  - reg
   - "#clock-cells"
   - clocks
   - clock-names
   - xlnx,speed-grade
   - xlnx,nr-outputs
 
+allOf:
+  - if:
+      required:
+        - xlnx,static-config
+    then:
+      required:
+        - xlnx,clk-mul-div
+    else:
+      required:
+        - reg
+      properties:
+        clocks:
+          minItems: 2
+        clock-names:
+          minItems: 2
+
 additionalProperties: false
 
 examples:
   - |
-    clock-controller@b0000000  {
+    clock-controller@b0000000 {
         compatible = "xlnx,clocking-wizard";
         reg = <0xb0000000 0x10000>;
         #clock-cells = <1>;
-        xlnx,static-config;
+        clocks = <&clkc 15>, <&clkc 18>;
+        clock-names = "clk_in1", "s_axi_aclk";
+        xlnx,nr-outputs = <6>;
         xlnx,speed-grade = <1>;
+    };
+
+  - |
+    clock-controller {
+        compatible = "xlnx,clocking-wizard";
+        #clock-cells = <1>;
+        clocks = <&clkc 15>;
+        clock-names = "clk_in1";
         xlnx,nr-outputs = <6>;
-        clock-names = "clk_in1", "s_axi_aclk";
-        clocks = <&clkc 15>, <&clkc 15>;
+        xlnx,speed-grade = <1>;
+        xlnx,static-config;
+        xlnx,clk-mul-div = <12 1>, <10 2>, <8 1>, <6 1>, <4 2>, <2 1>;
     };
 ...
-- 
2.34.1