[PATCH v4 2/6] dt-bindings: pwm: amlogic: add new compatible for meson8 pwm type

[Jerome Brunet <jbrunet@baylibre.com>]

Add a new compatible for the pwm found in the meson8 to sm1 Amlogic SoCs,
dealing with clocks differently. This does not enable new HW. It is meant
to fix a bad DT ABI for the currently supported HW.

The original clock bindings describe which input the PWM channel
multiplexer should pick among its possible parents, which are
hard-coded in the driver. As such, it is a setting tied to the driver
implementation and does not describe the HW.

The new bindings introduce here describe the clocks input of the PWM block
as they exist.

The old compatible is deprecated but kept to maintain ABI compatibility.

The SoC specific compatibles introduced match the SoC families supported
by the original bindings.

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
---
 .../devicetree/bindings/pwm/pwm-amlogic.yaml  | 50 +++++++++++++++++--
 1 file changed, 46 insertions(+), 4 deletions(-)

diff --git a/Documentation/devicetree/bindings/pwm/pwm-amlogic.yaml b/Documentation/devicetree/bindings/pwm/pwm-amlogic.yaml
index a1d382aacb82..eece390114a3 100644
--- a/Documentation/devicetree/bindings/pwm/pwm-amlogic.yaml
+++ b/Documentation/devicetree/bindings/pwm/pwm-amlogic.yaml
@@ -21,23 +21,35 @@ 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
+      - const: amlogic,meson8-pwm-v2
+      - 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
+      - const: amlogic,meson-s4-pwm
 
   reg:
     maxItems: 1
 
   clocks:
     minItems: 1
-    maxItems: 2
+    maxItems: 4
 
   clock-names:
     minItems: 1
@@ -58,7 +70,6 @@ allOf:
         compatible:
           contains:
             enum:
-              - amlogic,meson8-pwm
               - amlogic,meson8b-pwm
               - amlogic,meson-gxbb-pwm
               - amlogic,meson-gxbb-ao-pwm
@@ -68,11 +79,14 @@ 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 +95,27 @@ 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 +145,13 @@ 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";
-- 
2.42.0