dt-bindings: bus: renesas-bsc: convert bindings to json-schema

Convert Renesas Bus State Controller (BSC) bindings documentation to
json-schema.

Signed-off-by: Simon Horman <[e-mail]>
Signed-off-by: Rob Herring <[e-mail]>

Documentation/devicetree/bindings/bus/renesas,bsc.txt

···
-Renesas Bus State Controller (BSC)
-==================================
-
-The Renesas Bus State Controller (BSC, sometimes called "LBSC within Bus
-Bridge", or "External Bus Interface") can be found in several Renesas ARM SoCs.
-It provides an external bus for connecting multiple external devices to the
-SoC, driving several chip select lines, for e.g. NOR FLASH, Ethernet and USB.
-
-While the BSC is a fairly simple memory-mapped bus, it may be part of a PM
-domain, and may have a gateable functional clock.
-Before a device connected to the BSC can be accessed, the PM domain
-containing the BSC must be powered on, and the functional clock
-driving the BSC must be enabled.
-
-The bindings for the BSC extend the bindings for "simple-pm-bus".
-
-
-Required properties
-  - compatible: Must contain an SoC-specific value, and "renesas,bsc" and
-		"simple-pm-bus" as fallbacks.
-                SoC-specific values can be:
-		"renesas,bsc-r8a73a4" for R-Mobile APE6 (r8a73a4)
-		"renesas,bsc-sh73a0" for SH-Mobile AG5 (sh73a0)
-  - #address-cells, #size-cells, ranges: Must describe the mapping between
-		parent address and child address spaces.
-  - reg: Must contain the base address and length to access the bus controller.
-
-Optional properties:
-  - interrupts: Must contain a reference to the BSC interrupt, if available.
-  - clocks: Must contain a reference to the functional clock, if available.
-  - power-domains: Must contain a reference to the PM domain, if available.
-
-
-Example:
-
-	bsc: bus@fec10000 {
-		compatible = "renesas,bsc-sh73a0", "renesas,bsc",
-			     "simple-pm-bus";
-		#address-cells = <1>;
-		#size-cells = <1>;
-		ranges = <0 0 0x20000000>;
-		reg = <0xfec10000 0x400>;
-		interrupts = <0 39 IRQ_TYPE_LEVEL_HIGH>;
-		clocks = <&zb_clk>;
-		power-domains = <&pd_a4s>;
-	};

Documentation/devicetree/bindings/bus/renesas,bsc.yaml

···
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/bus/renesas,bsc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas Bus State Controller (BSC)
+
+maintainers:
+  - Geert Uytterhoeven <[e-mail]>
+
+description: |
+  The Renesas Bus State Controller (BSC, sometimes called "LBSC within Bus
+  Bridge", or "External Bus Interface") can be found in several Renesas ARM
+  SoCs.  It provides an external bus for connecting multiple external
+  devices to the SoC, driving several chip select lines, for e.g. NOR
+  FLASH, Ethernet and USB.
+
+  While the BSC is a fairly simple memory-mapped bus, it may be part of a
+  PM domain, and may have a gateable functional clock.  Before a device
+  connected to the BSC can be accessed, the PM domain containing the BSC
+  must be powered on, and the functional clock driving the BSC must be
+  enabled.
+
+  The bindings for the BSC extend the bindings for "simple-pm-bus".
+
+allOf:
+  - $ref: simple-pm-bus.yaml#
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - renesas,bsc-r8a73a4  # R-Mobile APE6 (r8a73a4)
+          - renesas,bsc-sh73a0   # SH-Mobile AG5 (sh73a0)
+      - const: renesas,bsc
+      - {} # simple-pm-bus, but not listed here to avoid false select
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+required:
+  - reg
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    bsc: bus@fec10000 {
+        compatible = "renesas,bsc-sh73a0", "renesas,bsc", "simple-pm-bus";
+        #address-cells = <1>;
+        #size-cells = <1>;
+        ranges = <0 0 0x20000000>;
+        reg = <0xfec10000 0x400>;
+        interrupts = <0 39 IRQ_TYPE_LEVEL_HIGH>;
+        clocks = <&zb_clk>;
+        power-domains = <&pd_a4s>;
+    };