dt-bindings: dpll: support acting as pin provider

Enable DPLL devices to act as pin providers for consumers (such as
Ethernet controllers or PHYs).

Add the '#dpll-pin-cells' property to the generic dpll-device.yaml
schema and mark it as required. This allows DPLL nodes to define pin
specifiers for their connected consumers.

Introduce a new header '<dt-bindings/dpll/dpll.h>' to define pin
direction macros (`DPLL_PIN_INPUT` and `DPLL_PIN_OUTPUT`). These macros
are intended to be used in the DT pin specifiers (inside 'dpll-pins'
properties of consumers) to describe the direction of the signal.

Update the 'microchip,zl30731.yaml' examples to include the new
'#dpll-pin-cells' property.

The core schema definitions for these properties are being added to
dt-schema in PR torvalds#183.

Link: devicetree-org/dt-schema#183
Signed-off-by: Ivan Vecera <[email protected]>
Signed-off-by: NipaLocal <nipa@local>

Author: ivecera

Documentation/devicetree/bindings/dpll/dpll-device.yaml

@@ -27,6 +27,13 @@ properties:
   "#size-cells":
     const: 0
 
+  "#dpll-pin-cells":
+    const: 2
+    description: |
+      - Specified pin index
+      - Specified pin direction. The macros are defined in
+        dt-bindings/dpll/dpll.h
+
   dpll-types:
     description: List of DPLL channel types, one per DPLL instance.
     $ref: /schemas/types.yaml#/definitions/non-unique-string-array
@@ -73,4 +80,7 @@ properties:
       - "#address-cells"
       - "#size-cells"
 
+required:
+  - "#dpll-pin-cells"
+
 additionalProperties: true

Documentation/devicetree/bindings/dpll/microchip,zl30731.yaml

@@ -44,6 +44,8 @@ examples:
       #size-cells = <0>;
 
       dpll@70 {
+        #dpll-pin-cells = <2>;
+
         compatible = "microchip,zl30732";
         reg = <0x70>;
         dpll-types = "pps", "eec";
@@ -80,6 +82,8 @@ examples:
       #size-cells = <0>;
 
       dpll@70 {
+        #dpll-pin-cells = <2>;
+
         compatible = "microchip,zl30731";
         reg = <0x70>;
         spi-max-frequency = <12500000>;

MAINTAINERS

@@ -7663,6 +7663,7 @@ F:	Documentation/devicetree/bindings/dpll/dpll-device.yaml
 F:	Documentation/devicetree/bindings/dpll/dpll-pin.yaml
 F:	Documentation/driver-api/dpll.rst
 F:	drivers/dpll/
+F:	include/dt-bindings/dpll/dpll.h
 F:	include/linux/dpll.h
 F:	include/uapi/linux/dpll.h
 

include/dt-bindings/dpll/dpll.h

@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause) */
+/*
+ * This header provides constants for DPLL bindings.
+ */
+
+#ifndef _DT_BINDINGS_DPLL_DPLL_H
+#define _DT_BINDINGS_DPLL_DPLL_H
+
+/* DPLL pin direction */
+#define DPLL_PIN_INPUT 0
+#define DPLL_PIN_OUTPUT 1
+
+#endif