dt-bindings: clock: convert stm32 rcc bindings to json-schema

The patch converts st,stm32-rcc.txt to the JSON schema, but it does more
than that. The old bindings, in fact, only covered the stm32f{4,7}
platforms and not the stm32h7. Therefore, to avoid patch submission tests
failing, it was necessary to add the corresponding compatible (i. e.
st,stm32h743-rcc) and specify that, in this case, 3 are the clocks instead
of the 2 required for the stm32f{4,7} platforms.
Additionally, the old bindings made no mention of the st,syscfg property,
which is used by both the stm32f{4,7} and the stm32h7 platforms.

The patch also fixes the files referencing to the old st,stm32-rcc.txt.

Signed-off-by: Dario Binacchi <[email protected]>
Reviewed-by: Krzysztof Kozlowski <[email protected]>

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Stephen Boyd <[email protected]>

Documentation/devicetree/bindings/clock/st,stm32-rcc.yaml

@@ -0,0 +1,108 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/clock/st,stm32-rcc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: STMicroelectronics STM32 Reset Clock Controller
+
+maintainers:
+  - Dario Binacchi <[email protected]>
+
+description: |
+  The RCC IP is both a reset and a clock controller.
+  The reset phandle argument is the bit number within the RCC registers bank,
+  starting from RCC base address.
+
+properties:
+  compatible:
+    oneOf:
+      - items:
+          - enum:
+              - st,stm32f42xx-rcc
+              - st,stm32f746-rcc
+              - st,stm32h743-rcc
+          - const: st,stm32-rcc
+      - items:
+          - enum:
+              - st,stm32f469-rcc
+          - const: st,stm32f42xx-rcc
+          - const: st,stm32-rcc
+      - items:
+          - enum:
+              - st,stm32f769-rcc
+          - const: st,stm32f746-rcc
+          - const: st,stm32-rcc
+
+  reg:
+    maxItems: 1
+
+  '#reset-cells':
+    const: 1
+
+  '#clock-cells':
+    enum: [1, 2]
+
+  clocks:
+    minItems: 2
+    maxItems: 3
+
+  st,syscfg:
+    $ref: /schemas/types.yaml#/definitions/phandle
+    description:
+      Phandle to system configuration controller. It can be used to control the
+      power domain circuitry.
+
+required:
+  - compatible
+  - reg
+  - '#reset-cells'
+  - '#clock-cells'
+  - clocks
+  - st,syscfg
+
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: st,stm32h743-rcc
+    then:
+      properties:
+        '#clock-cells':
+          const: 1
+          description: |
+            The clock index for the specified type.
+        clocks:
+          items:
+            - description: high speed external (HSE) clock input
+            - description: low speed external (LSE) clock input
+            - description: Inter-IC sound (I2S) clock input
+    else:
+      properties:
+        '#clock-cells':
+          const: 2
+          description: |
+            - The first cell is the clock type, possible values are 0 for
+              gated clocks and 1 otherwise.
+            - The second cell is the clock index for the specified type.
+        clocks:
+          items:
+            - description: high speed external (HSE) clock input
+            - description: Inter-IC sound (I2S) clock input
+
+additionalProperties: false
+
+examples:
+  # Reset and Clock Control Module node:
+  - |
+    clock-controller@58024400 {
+        compatible = "st,stm32h743-rcc", "st,stm32-rcc";
+        reg = <0x58024400 0x400>;
+        #clock-cells = <1>;
+        #reset-cells = <1>;
+        clocks = <&clk_hse>, <&clk_lse>, <&clk_i2s>;
+        st,syscfg = <&pwrcfg>;
+    };
+
+...

Documentation/devicetree/bindings/reset/st,stm32-rcc.txt

@@ -3,4 +3,4 @@ STMicroelectronics STM32 Peripheral Reset Controller
 
 The RCC IP is both a reset and a clock controller.
 
-Please see Documentation/devicetree/bindings/clock/st,stm32-rcc.txt
+Please see Documentation/devicetree/bindings/clock/st,stm32-rcc.yaml

include/dt-bindings/clock/stm32fx-clock.h

@@ -10,7 +10,7 @@
  * List of clocks which are not derived from system clock (SYSCLOCK)
  *
  * The index of these clocks is the secondary index of DT bindings
- * (see Documentation/devicetree/bindings/clock/st,stm32-rcc.txt)
+ * (see Documentation/devicetree/bindings/clock/st,stm32-rcc.yaml)
  *
  * e.g:
 	<assigned-clocks = <&rcc 1 CLK_LSE>;