dts: bindings: regulator: add nordic,nrf5[2]x-regulator[-hv]

Some Nordic SoCs, like nRF52 contain an internal regulator for the main
SoC supply. Depending on the SoC, the regulator can have multiple
configurations (e.g. single/double stage), which mainly depends on
supporting "high-voltage" mode or not (VDDH pin supply). This patch adds
bindings for nRF5X regulator and nRF52X HV regulator.

Signed-off-by: Gerard Marull-Paretas <gerard@teslabs.com>

dts/bindings/regulator/nordic,nrf52x-regulator-hv.yaml

@@ -0,0 +1,20 @@
+# Copyright (c), 2024 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+description: |
+  Nordic nRF52X regulator (high voltage stage of the main supply)
+
+compatible: "nordic,nrf52x-regulator-hv"
+
+include:
+  - name: base.yaml
+  - name: regulator.yaml
+    property-allowlist:
+      - regulator-name
+
+properties:
+  reg:
+    required: true
+
+  regulator-name:
+    required: true

dts/bindings/regulator/nordic,nrf5x-regulator.yaml

@@ -0,0 +1,24 @@
+# Copyright (c), 2024 Nordic Semiconductor ASA
+# SPDX-License-Identifier: Apache-2.0
+
+description: |
+  Nordic nRF5X regulator (fixed stage of the core supply)
+
+compatible: "nordic,nrf5x-regulator"
+
+include:
+  - name: base.yaml
+  - name: regulator.yaml
+    property-allowlist:
+      - regulator-name
+      - regulator-initial-mode
+
+properties:
+  reg:
+    required: true
+
+  regulator-name:
+    required: true
+
+  regulator-initial-mode:
+    required: true

include/zephyr/dt-bindings/regulator/nrf5x.h

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2024 Nordic Semiconductor ASA
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef ZEPHYR_INCLUDE_DT_BINDINGS_REGULATOR_NRF5X_H_
+#define ZEPHYR_INCLUDE_DT_BINDINGS_REGULATOR_NRF_H_
+
+/**
+ * @defgroup regulator_nrf5x nRF5X regulator devicetree helpers.
+ * @ingroup regulator_interface
+ * @{
+ */
+
+/**
+ * @name nRF5X regulator modes
+ * @{
+ */
+/** LDO mode */
+#define NRF5X_REG_MODE_LDO 0
+/** DC/DC mode */
+#define NRF5X_REG_MODE_DCDC 1
+/** @} */
+
+/** @} */
+
+#endif /* ZEPHYR_INCLUDE_DT_BINDINGS_REGULATOR_NRF5X_H_*/