dt-bindings: pwm: amlogic: Add a new binding for meson8 pwm types

The binding that is used up to now describe which input the PWM
channel multiplexer should pick among its possible parents,
which are hardcoded in the driver. This isn't a good binding in
the sense that it should describe hardware but not usage.

Add a new binding deprecating the old one that uses clocks in a
better way and how clocks are usually used today: The list of
clocks describe the inputs of the PWM block as they are realised
in hardware.

So deprecate the old bindings and introduce a compatible per SoC
family to replace these.

Signed-off-by: Jerome Brunet <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Uwe Kleine-König <[email protected]>

Author: jbrun3t

Documentation/devicetree/bindings/pwm/pwm-amlogic.yaml

@@ -21,23 +21,36 @@ properties:
           - amlogic,meson-g12a-ee-pwm
           - amlogic,meson-g12a-ao-pwm-ab
           - amlogic,meson-g12a-ao-pwm-cd
-          - amlogic,meson-s4-pwm
+        deprecated: true
       - items:
           - const: amlogic,meson-gx-pwm
           - const: amlogic,meson-gxbb-pwm
+        deprecated: true
       - items:
           - const: amlogic,meson-gx-ao-pwm
           - const: amlogic,meson-gxbb-ao-pwm
+        deprecated: true
       - items:
           - const: amlogic,meson8-pwm
           - const: amlogic,meson8b-pwm
+        deprecated: true
+      - enum:
+          - amlogic,meson8-pwm-v2
+          - amlogic,meson-s4-pwm
+      - items:
+          - enum:
+              - amlogic,meson8b-pwm-v2
+              - amlogic,meson-gxbb-pwm-v2
+              - amlogic,meson-axg-pwm-v2
+              - amlogic,meson-g12-pwm-v2
+          - const: amlogic,meson8-pwm-v2
 
   reg:
     maxItems: 1
 
   clocks:
     minItems: 1
-    maxItems: 2
+    maxItems: 4
 
   clock-names:
     minItems: 1
@@ -68,11 +81,14 @@ allOf:
               - amlogic,meson-g12a-ao-pwm-ab
               - amlogic,meson-g12a-ao-pwm-cd
     then:
-      # Historic bindings tied to the driver implementation
+      # Obsolete historic bindings tied to the driver implementation
       # The clocks provided here are meant to be matched with the input
       # known (hard-coded) in the driver and used to select pwm clock
       # source. Currently, the linux driver ignores this.
+      # This is kept to maintain ABI backward compatibility.
       properties:
+        clocks:
+          maxItems: 2
         clock-names:
           oneOf:
             - items:
@@ -81,6 +97,27 @@ allOf:
                 - const: clkin0
                 - const: clkin1
 
+  # Newer binding where clock describe the actual clock inputs of the pwm
+  # block. These are necessary but some inputs may be grounded.
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - amlogic,meson8-pwm-v2
+    then:
+      properties:
+        clocks:
+          minItems: 1
+          items:
+            - description: input clock 0 of the pwm block
+            - description: input clock 1 of the pwm block
+            - description: input clock 2 of the pwm block
+            - description: input clock 3 of the pwm block
+        clock-names: false
+      required:
+        - clocks
+
   # Newer IP block take a single input per channel, instead of 4 inputs
   # for both channels
   - if:
@@ -110,6 +147,13 @@ examples:
       clock-names = "clkin0", "clkin1";
       #pwm-cells = <3>;
     };
+  - |
+    pwm@2000 {
+      compatible = "amlogic,meson8-pwm-v2";
+      reg = <0x1000 0x10>;
+      clocks = <&xtal>, <0>, <&fdiv4>, <&fdiv5>;
+      #pwm-cells = <3>;
+    };
   - |
     pwm@1000 {
       compatible = "amlogic,meson-s4-pwm";