dt-bindings: Add devicetree bindings

Add snapshot of device tree bindings from keystone common kernel, branch
"android-mainline-keystone-qcom-release" at c4c12103f9c0 ("Snap for 9228065
from e32903b9a63bb558df8b803b076619c53c16baad to
android-mainline-keystone-qcom-release").

Change-Id: I7682079615cbd9f29340a5c1f2a1d84ec441a1f1
Signed-off-by: Melody Olvera <quic_molvera@quicinc.com>

bindings/example-schema.yaml

@@ -0,0 +1,261 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright 2018 Linaro Ltd.
+%YAML 1.2
+---
+# All the top-level keys are standard json-schema keywords except for
+# 'maintainers' and 'select'
+
+# $id is a unique identifier based on the filename. There may or may not be a
+# file present at the URL.
+$id: http://devicetree.org/schemas/example-schema.yaml#
+# $schema is the meta-schema this schema should be validated with.
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: An example schema annotated with jsonschema details
+
+maintainers:
+  - Rob Herring <robh@kernel.org>
+
+description: |
+  A more detailed multi-line description of the binding.
+
+  Details about the hardware device and any links to datasheets can go here.
+
+  Literal blocks are marked with the '|' at the beginning. The end is marked by
+  indentation less than the first line of the literal block. Lines also cannot
+  begin with a tab character.
+
+select: false
+  # 'select' is a schema applied to a DT node to determine if this binding
+  # schema should be applied to the node. It is optional and by default the
+  # possible compatible strings are extracted and used to match.
+
+  # In this case, a 'false' schema will never match.
+
+properties:
+  # A dictionary of DT properties for this binding schema
+  compatible:
+    # More complicated schema can use oneOf (XOR), anyOf (OR), or allOf (AND)
+    # to handle different conditions.
+    # In this case, it's needed to handle a variable number of values as there
+    # isn't another way to express a constraint of the last string value.
+    # The boolean schema must be a list of schemas.
+    oneOf:
+      - items:
+          # items is a list of possible values for the property. The number of
+          # values is determined by the number of elements in the list.
+          # Order in lists is significant, order in dicts is not
+          # Must be one of the 1st enums followed by the 2nd enum
+          #
+          # Each element in items should be 'enum' or 'const'
+          - enum:
+              - vendor,soc4-ip
+              - vendor,soc3-ip
+              - vendor,soc2-ip
+          - enum:
+              - vendor,soc1-ip
+        # additionalItems being false is implied
+        # minItems/maxItems equal to 2 is implied
+      - items:
+          # 'const' is just a special case of an enum with a single possible value
+          - const: vendor,soc1-ip
+
+  reg:
+    # The core schema already checks that reg values are numbers, so device
+    # specific schema don't need to do those checks.
+    # The description of each element defines the order and implicitly defines
+    # the number of reg entries.
+    items:
+      - description: core registers
+      - description: aux registers
+    # minItems/maxItems equal to 2 is implied
+
+  reg-names:
+    # The core schema enforces this (*-names) is a string array
+    items:
+      - const: core
+      - const: aux
+
+  clocks:
+    # Cases that have only a single entry just need to express that with maxItems
+    maxItems: 1
+    description: bus clock. A description is only needed for a single item if
+      there's something unique to add.
+      The items should have a fixed order, so pattern matching names are
+      discouraged.
+
+  clock-names:
+    items:
+      - const: bus
+
+  interrupts:
+    # Either 1 or 2 interrupts can be present
+    minItems: 1
+    items:
+      - description: tx or combined interrupt
+      - description: rx interrupt
+    description:
+      A variable number of interrupts warrants a description of what conditions
+      affect the number of interrupts. Otherwise, descriptions on standard
+      properties are not necessary.
+      The items should have a fixed order, so pattern matching names are
+      discouraged.
+
+  interrupt-names:
+    # minItems must be specified here because the default would be 2
+    minItems: 1
+    items:
+      - const: tx irq
+      - const: rx irq
+
+  # Property names starting with '#' must be quoted
+  '#interrupt-cells':
+    # A simple case where the value must always be '2'.
+    # The core schema handles that this must be a single integer.
+    const: 2
+
+  interrupt-controller: true
+    # The core checks this is a boolean, so just have to list it here to be
+    # valid for this binding.
+
+  clock-frequency:
+    # The type is set in the core schema. Per-device schema only need to set
+    # constraints on the possible values.
+    minimum: 100
+    maximum: 400000
+    # The value that should be used if the property is not present
+    default: 200
+
+  foo-gpios:
+    maxItems: 1
+    description: A connection of the 'foo' gpio line.
+
+  # *-supply is always a single phandle, so nothing more to define.
+  foo-supply: true
+
+  # Vendor-specific properties
+  #
+  # Vendor-specific properties have slightly different schema requirements than
+  # common properties. They must have at least a type definition and
+  # 'description'.
+  vendor,int-property:
+    description: Vendor-specific properties must have a description
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [2, 4, 6, 8, 10]
+
+  vendor,bool-property:
+    description: Vendor-specific properties must have a description. Boolean
+      properties are one case where the json-schema 'type' keyword can be used
+      directly.
+    type: boolean
+
+  vendor,string-array-property:
+    description: Vendor-specific properties should reference a type in the
+      core schema.
+    $ref: /schemas/types.yaml#/definitions/string-array
+    items:
+      - enum: [foo, bar]
+      - enum: [baz, boo]
+
+  vendor,property-in-standard-units-microvolt:
+    description: Vendor-specific properties having a standard unit suffix
+      don't need a type.
+    enum: [ 100, 200, 300 ]
+
+  vendor,int-array-variable-length-and-constrained-values:
+    description: Array might define what type of elements might be used (e.g.
+      their range).
+    $ref: /schemas/types.yaml#/definitions/uint32-array
+    minItems: 2
+    maxItems: 3
+    items:
+      minimum: 0
+      maximum: 8
+
+  child-node:
+    description: Child nodes are just another property from a json-schema
+      perspective.
+    type: object  # DT nodes are json objects
+    properties:
+      vendor,a-child-node-property:
+        description: Child node properties have all the same schema
+          requirements.
+        type: boolean
+
+    required:
+      - vendor,a-child-node-property
+
+# Describe the relationship between different properties
+dependencies:
+  # 'vendor,bool-property' is only allowed when 'vendor,string-array-property'
+  # is present
+  vendor,bool-property: [ 'vendor,string-array-property' ]
+  # Expressing 2 properties in both orders means all of the set of properties
+  # must be present or none of them.
+  vendor,string-array-property: [ 'vendor,bool-property' ]
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - interrupt-controller
+
+# if/then schema can be used to handle conditions on a property affecting
+# another property. A typical case is a specific 'compatible' value changes the
+# constraints on other properties.
+#
+# For multiple 'if' schema, group them under an 'allOf'.
+#
+# If the conditionals become too unweldy, then it may be better to just split
+# the binding into separate schema documents.
+allOf:
+  - if:
+      properties:
+        compatible:
+          contains:
+            const: vendor,soc2-ip
+    then:
+      required:
+        - foo-supply
+    else:
+      # If otherwise the property is not allowed:
+      properties:
+        foo-supply: false
+  # Altering schema depending on presence of properties is usually done by
+  # dependencies (see above), however some adjustments might require if:
+  - if:
+      required:
+        - vendor,bool-property
+    then:
+      properties:
+        vendor,int-property:
+          enum: [2, 4, 6]
+
+# Ideally, the schema should have this line otherwise any other properties
+# present are allowed. There's a few common properties such as 'status' and
+# 'pinctrl-*' which are added automatically by the tooling.
+#
+# This can't be used in cases where another schema is referenced
+# (i.e. allOf: [{$ref: ...}]).
+# If and only if another schema is referenced and arbitrary children nodes can
+# appear, "unevaluatedProperties: false" could be used.  A typical example is
+# an I2C controller where no name pattern matching for children can be added.
+additionalProperties: false
+
+examples:
+  # Examples are now compiled with dtc and validated against the schemas
+  #
+  # Examples have a default #address-cells and #size-cells value of 1. This can
+  # be overridden or an appropriate parent bus node should be shown (such as on
+  # i2c buses).
+  #
+  # Any includes used have to be explicitly included. Use 4-space indentation.
+  - |
+    node@1000 {
+        compatible = "vendor,soc4-ip", "vendor,soc1-ip";
+        reg = <0x1000 0x80>,
+              <0x3000 0x80>;
+        reg-names = "core", "aux";
+        interrupts = <10>;
+        interrupt-controller;
+    };