On Tue, Nov 12, 2019 at 02:51:46PM -0800, Stephen Boyd wrote:

Quoting Rajan Vaja (2019-11-12 05:16:14)

quoted

diff --git a/Documentation/devicetree/bindings/clock/xlnx,versal-clk.yaml b/Documentation/devicetree/bindings/clock/xlnx,versal-clk.yaml
new file mode 100644
index 0000000..da82f6a
--- /dev/null
+++ b/Documentation/devicetree/bindings/clock/xlnx,versal-clk.yaml

@@ -0,0 +1,67 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/bindings/clock/xlnx,versal-clk.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Xilinx Versal clock controller
+
+maintainers:
+  - Michal Simek <michal.simek@xilinx.com>
+  - Jolly Shah <jolly.shah@xilinx.com>
+  - Rajan Vaja <rajan.vaja@xilinx.com>
+
+description: |
+  The clock controller is a h/w block of Xilinx versal clock tree. It reads

hardware instead of h/w

quoted

+  required input clock frequencies from the devicetree and acts as clock
+  provider for all clock consumers of PS clocks. See clock_bindings.txt
+  for more information on the generic clock bindings.

Please drop this last sentence about clock_bindings.txt

quoted

+
+properties:
+  compatible:
+    const: xlnx,versal-clk
+
+  "#clock-cells":
+    const: 1
+
+  clocks:
+    description: List of clock specifiers which are external input
+      clocks to the given clock controller.
+    minItems: 3
+    maxItems: 3

Can drop these. Implied by by 'items' list.

quoted

+    items:
+      - description: ref clk
+      - description: alternate ref clk
+      - description: pl alternate ref clk

What is "pl"? Can you clarify?

quoted

+
+  clock-names:
+    minItems: 3
+    maxItems: 3

Same here.

quoted

+    items:
+      - const: ref_clk
+      - const: alt_ref_clk
+      - const: pl_alt_ref_clk

'_clk' is redundant.

quoted

+
+required:
+  - compatible
+  - "#clock-cells"
+  - clocks
+  - clock-names
+
+additionalProperties: false
+
+examples:
+  - |
+    firmware {
+      zynqmp_firmware: zynqmp-firmware {
+        compatible = "xlnx,zynqmp-firmware";
+        method = "smc";

Is there a way to say in the binding that this must be a child of a
xlnx,zynqmp-firmware node? That would be ideal so we can constrain this
to that location somehow.

Yes. Add the node name as a property to the f/w schema and reference 
($ref) this file and add 'select: false' to this one. The problem is the 
firmware binding is probably not yet a schema. Once it is a schema, this 
example will start failing because it's incomplete. For that reason, I 
prefer the examples in these cases (inc MFDs) in the base schema and not 
in the child node schemas.

quoted

+        versal_clk: clock-controller {
+          #clock-cells = <1>;
+          compatible = "xlnx,versal-clk";
+          clocks = <&ref_clk>, <&alt_ref_clk>, <&pl_alt_ref_clk>;
+          clock-names = "ref_clk", "alt_ref_clk", "pl_alt_ref_clk";
+        };
+      };
+    };
+...

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