Add DT schema for the pinctrl driver of NXP S32 SoC family.

Signed-off-by: Larisa Grigore <redacted>
Signed-off-by: Ghennadi Procopciuc <Ghennadi.Procopciuc@oss.nxp.com>
Signed-off-by: Chester Lin <redacted>
---

Changes in v3:
- Remove the minItems from reg because there's no optional item for s32g2.
- List supported properties of pinmux-node and pincfg-node and add more
  descriptions.
- Adjust the location of "required:".
- Fix descriptions and wordings.
- Rename the yaml file to nxp,s32g2-siul2-pinctrl.yaml.

Changes in v2:
- Remove the "nxp,pins" property since it has been moved into the driver.
- Add descriptions for reg entries.
- Refine the compatible name from "nxp,s32g-..." to "nxp,s32g2-...".
- Fix schema issues and revise the example.
- Fix the copyright format suggested by NXP.

 .../pinctrl/nxp,s32g2-siul2-pinctrl.yaml      | 129 ++++++++++++++++++
 1 file changed, 129 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/pinctrl/nxp,s32g2-siul2-pinctrl.yaml

diff --git a/Documentation/devicetree/bindings/pinctrl/nxp,s32g2-siul2-pinctrl.yaml b/Documentation/devicetree/bindings/pinctrl/nxp,s32g2-siul2-pinctrl.yaml
new file mode 100644
index 000000000000..1554ce14214a
--- /dev/null
+++ b/Documentation/devicetree/bindings/pinctrl/nxp,s32g2-siul2-pinctrl.yaml

@@ -0,0 +1,129 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+# Copyright 2022 NXP
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pinctrl/nxp,s32g2-siul2-pinctrl.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NXP S32G2 pin controller
+
+maintainers:
+  - Ghennadi Procopciuc <Ghennadi.Procopciuc@oss.nxp.com>
+  - Chester Lin <clin@suse.com>
+
+description: |
+  S32G2 pinmux is implemented in SIUL2 (System Integration Unit Lite2),
+  whose memory map is split into two regions:
+    SIUL2_0 @ 0x4009c000
+    SIUL2_1 @ 0x44010000
+
+  Every SIUL2 region has multiple register types, and here only MSCR and
+  IMCR registers need to be revealed for kernel to configure pinmux.
+
+  Please note that some register indexes are reserved in S32G2, such as
+  MSCR102-MSCR111, MSCR123-MSCR143, IMCR84-IMCR118 and IMCR398-IMCR429.
+
+properties:
+  compatible:
+    enum:
+      - nxp,s32g2-siul2-pinctrl
+
+  reg:
+    description: |
+      A list of MSCR/IMCR register regions to be reserved.
+      - MSCR (Multiplexed Signal Configuration Register)
+        An MSCR register can configure the associated pin as either a GPIO pin
+        or a function output pin depends on the selected signal source.
+      - IMCR (Input Multiplexed Signal Configuration Register)
+        An IMCR register can configure the associated pin as function input
+        pin depends on the selected signal source.
+    items:
+      - description: MSCR registers group 0 in SIUL2_0
+      - description: MSCR registers group 1 in SIUL2_1
+      - description: MSCR registers group 2 in SIUL2_1
+      - description: IMCR registers group 0 in SIUL2_0
+      - description: IMCR registers group 1 in SIUL2_1
+      - description: IMCR registers group 2 in SIUL2_1
+
+patternProperties:
+  '-pins$':
+    type: object
+    additionalProperties: false
+
+    patternProperties:
+      '-grp[0-9]$':
+        type: object
+        allOf:
+          - $ref: pinmux-node.yaml#
+          - $ref: pincfg-node.yaml#
+        description: |
+          Pinctrl node's client devices specify pin muxes using subnodes,
+          which in turn use the standard properties below.
+
+        properties:
+          bias-disable: true
+          bias-high-impedance: true
+          bias-pull-up: true
+          bias-pull-down: true
+          drive-open-drain: true
+          input-enable: true
+          output-enable: true
+
+          pinmux:
+            description: |
+               An integer array for representing pinmux configurations of
+               a device. Each integer consists of a PIN_ID and a 4-bit
+               selected signal source(SSS) as IOMUX setting, which is
+               calculated as: pinmux = (PIN_ID << 4 | SSS)
+
+          slew-rate:
+            description: |
+              0: 208MHz
+              1-3: Reserved
+              4: 166MHz
+              5: 150MHz
+              6: 133MHz
+              7: 83MHz
+            enum: [0, 4, 5, 6, 7]