dt-bindings: regulator: Document ROHM BD71282 regulator bindings

Document ROHM BD71828 PMIC regulator device tree bindings.
Signed-off-by: NMatti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Link: https://lore.kernel.org/r/0985fec1cce98b1db66e5df2d9bcf2dfd9c224a7.1576054779.git.matti.vaittinen@fi.rohmeurope.comSigned-off-by: NMark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/regulator/rohm,bd71828-regulator.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/regulator/rohm,bd71828-regulator.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: ROHM BD71828 Power Management Integrated Circuit regulators
+
+maintainers:
+  - Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
+
+description: |
+  This module is part of the ROHM BD71828 MFD device. For more details
+  see Documentation/devicetree/bindings/mfd/rohm,bd71828-pmic.yaml.
+
+  The regulator controller is represented as a sub-node of the PMIC node
+  on the device tree.
+
+  Regulator nodes should be named to BUCK_<number> and LDO_<number>.
+  The valid names for BD71828 regulator nodes are
+  BUCK1, BUCK2, BUCK3, BUCK4, BUCK5, BUCK6, BUCK7
+  LDO1, LDO2, LDO3, LDO4, LDO5, LDO6, LDO7
+
+patternProperties:
+  "^LDO[1-7]$":
+    type: object
+    allOf:
+      - $ref: regulator.yaml#
+    description:
+      Properties for single LDO regulator.
+
+    properties:
+      regulator-name:
+        pattern: "^ldo[1-7]$"
+        description:
+          should be "ldo1", ..., "ldo7"
+
+  "^BUCK[1-7]$":
+    type: object
+    allOf:
+      - $ref: regulator.yaml#
+    description:
+      Properties for single BUCK regulator.
+
+    properties:
+      regulator-name:
+        pattern: "^buck[1-7]$"
+        description:
+          should be "buck1", ..., "buck7"
+
+      rohm,dvs-run-voltage:
+        allOf:
+          - $ref: "/schemas/types.yaml#/definitions/uint32"
+          - minimum: 0
+            maximum: 3300000
+        description:
+          PMIC default "RUN" state voltage in uV. See below table for
+          bucks which support this. 0 means disabled.
+
+      rohm,dvs-idle-voltage:
+        allOf:
+          - $ref: "/schemas/types.yaml#/definitions/uint32"
+          - minimum: 0
+            maximum: 3300000
+        description:
+          PMIC default "IDLE" state voltage in uV. See below table for
+          bucks which support this. 0 means disabled.
+
+      rohm,dvs-suspend-voltage:
+        allOf:
+          - $ref: "/schemas/types.yaml#/definitions/uint32"
+          - minimum: 0
+            maximum: 3300000
+        description:
+          PMIC default "SUSPEND" state voltage in uV. See below table for
+          bucks which support this. 0 means disabled.
+
+      rohm,dvs-lpsr-voltage:
+        allOf:
+          - $ref: "/schemas/types.yaml#/definitions/uint32"
+          - minimum: 0
+            maximum: 3300000
+        description:
+          PMIC default "LPSR" state voltage in uV. See below table for
+          bucks which support this. 0 means disabled.
+
+        # Supported default DVS states:
+        #     buck       |    run     |   idle    | suspend  | lpsr
+        #--------------------------------------------------------------
+        # 1, 2, 6, and 7 | supported  | supported | supported (*)
+        #--------------------------------------------------------------
+        # 3, 4, and 5    |                    supported (**)
+        #--------------------------------------------------------------
+        #
+        #(*)  LPSR and SUSPEND states use same voltage but both states have own
+        #     enable /
+        #     disable settings. Voltage 0 can be specified for a state to make
+        #     regulator disabled on that state.
+        #
+        #(**) All states use same voltage but have own enable / disable
+        #     settings. Voltage 0 can be specified for a state to make
+        #     regulator disabled on that state.
+
+    required:
+      - regulator-name
+  additionalProperties: false
+additionalProperties: false