dt-bindings: sram: Convert SRAM bindings to json-schema

Convert generic mmio-sram bindings to DT schema format using
json-schema.  Require the address/size cells to be 1, not equal to root
node.  This also fixes the check for clocks property to be in main root
node instead of children.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/sram/sram.yaml

@@ -0,0 +1,136 @@
+# SPDX-License-Identifier: GPL-2.0
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/sram/sram.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Generic on-chip SRAM
+
+maintainers:
+  - Rob Herring <robh@kernel.org>
+
+description: |+
+  Simple IO memory regions to be managed by the genalloc API.
+
+  Each child of the sram node specifies a region of reserved memory. Each
+  child node should use a 'reg' property to specify a specific range of
+  reserved memory.
+
+  Following the generic-names recommended practice, node names should
+  reflect the purpose of the node. Unit address (@<address>) should be
+  appended to the name.
+
+properties:
+  $nodename:
+    pattern: "^sram(@.*)?"
+
+  compatible:
+    contains:
+      enum:
+        - mmio-sram
+        - atmel,sama5d2-securam
+
+  reg:
+    maxItems: 1
+
+  clocks:
+    description:
+      A list of phandle and clock specifier pair that controls the single
+      SRAM clock.
+
+  "#address-cells":
+    const: 1
+
+  "#size-cells":
+    const: 1
+
+  ranges:
+    description:
+      Should translate from local addresses within the sram to bus addresses.
+
+  no-memory-wc:
+    description:
+      The flag indicating, that SRAM memory region has not to be remapped
+      as write combining. WC is used by default.
+    type: boolean
+
+patternProperties:
+  "^([a-z]*-)?sram@[a-f0-9]+$":
+    type: object
+    description:
+      Each child of the sram node specifies a region of reserved memory.
+    properties:
+      compatible:
+        description:
+          Should contain a vendor specific string in the form
+          <vendor>,[<device>-]<usage>
+
+      reg:
+        description:
+          IO mem address range, relative to the SRAM range.
+        maxItems: 1
+
+      pool:
+        description:
+          Indicates that the particular reserved SRAM area is addressable
+          and in use by another device or devices.
+        type: boolean
+
+      export:
+        description:
+          Indicates that the reserved SRAM area may be accessed outside
+          of the kernel, e.g. by bootloader or userspace.
+        type: boolean
+
+      protect-exec:
+        description: |
+          Same as 'pool' above but with the additional constraint that code
+          will be run from the region and that the memory is maintained as
+          read-only, executable during code execution. NOTE: This region must
+          be page aligned on start and end in order to properly allow
+          manipulation of the page attributes.
+        type: boolean
+
+      label:
+        description:
+          The name for the reserved partition, if omitted, the label is taken
+          from the node name excluding the unit address.
+
+    required:
+      - reg
+
+    additionalProperties: false
+
+required:
+  - compatible
+  - reg
+  - "#address-cells"
+  - "#size-cells"
+  - ranges
+
+additionalProperties: false
+
+examples:
+  - |
+    sram@5c000000 {
+        compatible = "mmio-sram";
+        reg = <0x5c000000 0x40000>; /* 256 KiB SRAM at address 0x5c000000 */
+
+        #address-cells = <1>;
+        #size-cells = <1>;
+        ranges = <0 0x5c000000 0x40000>;
+
+        smp-sram@100 {
+            reg = <0x100 0x50>;
+        };
+
+        device-sram@1000 {
+            reg = <0x1000 0x1000>;
+            pool;
+        };
+
+        exported-sram@20000 {
+            reg = <0x20000 0x20000>;
+            export;
+        };
+    };