dt-bindings: pinctrl: imx: Add fsl,scu-iomux yaml file

In order to replace the fsl,scu txt file from bindings/arm/freescale,
we need to split it between the right subsystems. This patch documents
separately the 'iomux/pinctrl' child node of the SCU main node.

Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
Signed-off-by: Viorel Suman <viorel.suman@nxp.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

Documentation/devicetree/bindings/arm/freescale/fsl,scu.txt

@@ -79,33 +79,7 @@ Required properties:
 			See detailed Resource ID list from:
 			include/dt-bindings/firmware/imx/rsrc.h
 
-Pinctrl bindings based on SCU Message Protocol
-------------------------------------------------------------
-
-This binding uses the i.MX common pinctrl binding[3].
-
-Required properties:
-- compatible:		Should be one of:
-			"fsl,imx8qm-iomuxc",
-			"fsl,imx8qxp-iomuxc",
-			"fsl,imx8dxl-iomuxc".
-
-Required properties for Pinctrl sub nodes:
-- fsl,pins:		Each entry consists of 3 integers which represents
-			the mux and config setting for one pin. The first 2
-			integers <pin_id mux_mode> are specified using a
-			PIN_FUNC_ID macro, which can be found in
-			<dt-bindings/pinctrl/pads-imx8qm.h>,
-			<dt-bindings/pinctrl/pads-imx8qxp.h>,
-			<dt-bindings/pinctrl/pads-imx8dxl.h>.
-			The last integer CONFIG is the pad setting value like
-			pull-up on this pin.
-
-			Please refer to i.MX8QXP Reference Manual for detailed
-			CONFIG settings.
-
 [2] Documentation/devicetree/bindings/power/power-domain.yaml
-[3] Documentation/devicetree/bindings/pinctrl/fsl,imx-pinctrl.txt
 
 RTC bindings based on SCU Message Protocol
 ------------------------------------------------------------
@@ -184,18 +158,6 @@ firmware {
 			  &lsio_mu1 1 3
 			  &lsio_mu1 3 3>;
 
-		iomuxc {
-			compatible = "fsl,imx8qxp-iomuxc";
-
-			pinctrl_lpuart0: lpuart0grp {
-				fsl,pins = <
-					SC_P_UART0_RX_ADMA_UART0_RX	0x06000020
-					SC_P_UART0_TX_ADMA_UART0_TX	0x06000020
-				>;
-			};
-			...
-		};
-
 		ocotp: imx8qx-ocotp {
 			compatible = "fsl,imx8qxp-scu-ocotp";
 			#address-cells = <1>;
@@ -234,7 +196,5 @@ firmware {
 
 serial@5a060000 {
 	...
-	pinctrl-names = "default";
-	pinctrl-0 = <&pinctrl_lpuart0>;
 	power-domains = <&pd IMX_SC_R_UART_0>;
 };

Documentation/devicetree/bindings/pinctrl/fsl,scu-pinctrl.yaml

@@ -0,0 +1,74 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/pinctrl/fsl,scu-pinctrl.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: i.MX SCU Client Device Node - Pinctrl bindings based on SCU Message Protocol
+
+maintainers:
+  - Dong Aisheng <aisheng.dong@nxp.com>
+
+description: i.MX SCU Client Device Node
+  Client nodes are maintained as children of the relevant IMX-SCU device node.
+  This binding uses the i.MX common pinctrl binding.
+  (Documentation/devicetree/bindings/pinctrl/fsl,imx-pinctrl.txt)
+
+allOf:
+  - $ref: pinctrl.yaml#
+
+properties:
+  compatible:
+    enum:
+      - fsl,imx8qm-iomuxc
+      - fsl,imx8qxp-iomuxc
+      - fsl,imx8dxl-iomuxc
+
+patternProperties:
+  'grp$':
+    type: object
+    description:
+      Pinctrl node's client devices use subnodes for desired pin configuration.
+      Client device subnodes use below standard properties.
+
+    properties:
+      fsl,pins:
+        description:
+          each entry consists of 3 integers and represents the pin ID, the mux value
+          and pad setting for the pin. The first 2 integers - pin_id and mux_val - are
+          specified using a PIN_FUNC_ID macro, which can be found in
+          <include/dt-bindings/pinctrl/pads-imx8qxp.h>. The last integer is
+          the pad setting value like pull-up on this pin. Please refer to the
+          appropriate i.MX8 Reference Manual for detailed pad CONFIG settings.
+        $ref: /schemas/types.yaml#/definitions/uint32-matrix
+        items:
+          items:
+            - description: |
+                "pin_id" indicates the pin ID
+            - description: |
+                "mux_val" indicates the mux value to be applied.
+            - description: |
+                "pad_setting" indicates the pad configuration value to be applied.
+
+    required:
+      - fsl,pins
+
+    additionalProperties: false
+
+required:
+  - compatible
+
+additionalProperties: false
+
+examples:
+  - |
+    pinctrl {
+        compatible = "fsl,imx8qxp-iomuxc";
+
+        pinctrl_lpuart0: lpuart0grp {
+            fsl,pins = <
+                111 0 0x06000020
+                112 0 0x06000020
+            >;
+        };
+    };