Add bindings for the regulators found in the MediaTek MT6316 PMIC,
usually found in board designs using the MT6991 Dimensity 9400 and
on MT8196 Kompanio SoC for Chromebooks.

This chip is fully controlled by SPMI and has multiple variants
providing different phase configurations.

Link: https://lore.kernel.org/r/20250624073548.29732-2-angelogioacchino.delregno@collabora.com (local)
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
 .../regulator/mediatek,mt6316b-regulator.yaml | 46 +++++++++++++++++++
 .../regulator/mediatek,mt6316c-regulator.yaml | 46 +++++++++++++++++++
 .../regulator/mediatek,mt6316d-regulator.yaml | 41 +++++++++++++++++
 3 files changed, 133 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/regulator/mediatek,mt6316b-regulator.yaml
 create mode 100644 Documentation/devicetree/bindings/regulator/mediatek,mt6316c-regulator.yaml
 create mode 100644 Documentation/devicetree/bindings/regulator/mediatek,mt6316d-regulator.yaml

diff --git a/Documentation/devicetree/bindings/regulator/mediatek,mt6316b-regulator.yaml b/Documentation/devicetree/bindings/regulator/mediatek,mt6316b-regulator.yaml
new file mode 100644
index 000000000000..e7a6b70cdab2
--- /dev/null
+++ b/Documentation/devicetree/bindings/regulator/mediatek,mt6316b-regulator.yaml

@@ -0,0 +1,46 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/regulator/mediatek,mt6316b-regulator.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: MediaTek MT6316 BP/VP SPMI PMIC Regulators
+
+maintainers:
+  - AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
+
+description:
+  The MediaTek MT6316BP/VP PMICs are fully controlled by SPMI interface, both
+  feature four step-down DC/DC (buck) converters, and provides 2+2 Phases,
+  joining Buck 1+2 for the first phase, and Buck 3+4 for the second phase.
+
+properties:
+  compatible:
+    const: mediatek,mt6316b-regulator
+
+  vbuck12:
+    type: object
+    $ref: regulator.yaml#
+    unevaluatedProperties: false
+
+  vbuck34:
+    type: object
+    $ref: regulator.yaml#
+    unevaluatedProperties: false
+
+additionalProperties: false
+
+examples:
+  - |
+    pmic {