dt-bindings: misc: Convert olpc,xo1.75-ec to json-schema

Convert the OLPC XO-1.75 Embedded Controller binding to DT schema format
using json-schema.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Link: https://lore.kernel.org/r/20200718211244.187938-1-lkundrak@v3.skSigned-off-by: Rob Herring <robh@kernel.org>

Documentation/devicetree/bindings/misc/olpc,xo1.75-ec.txt

-OLPC XO-1.75 Embedded Controller
-
-Required properties:
-- compatible: Should be "olpc,xo1.75-ec".
-- cmd-gpios: gpio specifier of the CMD pin
-
-The embedded controller requires the SPI controller driver to signal readiness
-to receive a transfer (that is, when TX FIFO contains the response data) by
-strobing the ACK pin with the ready signal. See the "ready-gpios" property of the
-SSP binding as documented in:
-<Documentation/devicetree/bindings/spi/marvell,mmp2-ssp.yaml>.
-
-Example:
-	&ssp3 {
-		spi-slave;
-		ready-gpios = <&gpio 125 GPIO_ACTIVE_HIGH>;
-
-		slave {
-			compatible = "olpc,xo1.75-ec";
-			spi-cpha;
-			cmd-gpios = <&gpio 155 GPIO_ACTIVE_HIGH>;
-		};
-	};

Documentation/devicetree/bindings/misc/olpc,xo1.75-ec.yaml

+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+# Copyright (C) 2019,2020 Lubomir Rintel <lkundrak@v3.sk>
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/misc/olpc,xo1.75-ec.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: OLPC XO-1.75 Embedded Controller bindings
+
+description: |
+  This binding describes the Embedded Controller acting as a SPI bus master
+  on a OLPC XO-1.75 laptop computer.
+
+  The embedded controller requires the SPI controller driver to signal
+  readiness to receive a transfer (that is, when TX FIFO contains the
+  response data) by strobing the ACK pin with the ready signal. See the
+  "ready-gpios" property of the SSP binding as documented in:
+  <Documentation/devicetree/bindings/spi/marvell,mmp2-ssp.yaml>.
+
+maintainers:
+  - Lubomir Rintel <lkundrak@v3.sk>
+
+properties:
+  compatible:
+    const: olpc,xo1.75-ec
+
+  cmd-gpios:
+    description: GPIO uspecifier of the CMD pin
+    maxItems: 1
+
+required:
+  - compatible
+  - cmd-gpios
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    spi {
+      spi-slave;
+      ready-gpios = <&gpio 125 GPIO_ACTIVE_HIGH>;
+
+      slave {
+        compatible = "olpc,xo1.75-ec";
+        spi-cpha;
+        cmd-gpios = <&gpio 155 GPIO_ACTIVE_HIGH>;
+      };
+    };
+
+...