dt-bindings:iio:afe:voltage-divider: txt to yaml conversion

Simple binding so straight forward conversion, though did require
adding a separate binding document for the max1027 to reflect
its abilities to provide channels to consumers.
Signed-off-by: NJonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: NRob Herring <robh@kernel.org>
Cc: Peter Rosin <peda@axentia.se>
Link: https://lore.kernel.org/r/20201031181242.742301-9-jic23@kernel.org

Documentation/devicetree/bindings/iio/afe/voltage-divider.txt

-Voltage divider
-===============
-
-When an io-channel measures the midpoint of a voltage divider, the
-interesting voltage is often the voltage over the full resistance
-of the divider. This binding describes the voltage divider in such
-a curcuit.
-
-    Vin ----.
-            |
-         .-----.
-         |  R  |
-         '-----'
-            |
-            +---- Vout
-            |
-         .-----.
-         | Rout|
-         '-----'
-            |
-           GND
-
-Required properties:
-- compatible : "voltage-divider"
-- io-channels : Channel node of a voltage io-channel measuring Vout.
-- output-ohms : Resistance Rout over which the output voltage is measured.
-	        See full-ohms.
-- full-ohms : Resistance R + Rout for the full divider. The io-channel
-	      is scaled by the Rout / (R + Rout) quotient.
-
-Example:
-The system voltage is circa 12V, but divided down with a 22/222
-voltage divider (R = 200 Ohms, Rout = 22 Ohms) and fed to an ADC.
-
-sysv {
-	compatible = "voltage-divider";
-	io-channels = <&maxadc 1>;
-
-	/* Scale the system voltage by 22/222 to fit the ADC range. */
-	output-ohms = <22>;
-	full-ohms = <222>; /* 200 + 22 */
-};
-
-&spi {
-	maxadc: adc@0 {
-		compatible = "maxim,max1027";
-		reg = <0>;
-		#io-channel-cells = <1>;
-		interrupt-parent = <&gpio5>;
-		interrupts = <15 IRQ_TYPE_EDGE_RISING>;
-		spi-max-frequency = <1000000>;
-	};
-};

Documentation/devicetree/bindings/iio/afe/voltage-divider.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/afe/voltage-divider.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Voltage divider
+
+maintainers:
+  - Peter Rosin <peda@axentia.se>
+
+description: |
+  When an io-channel measures the midpoint of a voltage divider, the
+  interesting voltage is often the voltage over the full resistance
+  of the divider. This binding describes the voltage divider in such
+  a curcuit.
+
+    Vin ----.
+            |
+         .-----.
+         |  R  |
+         '-----'
+            |
+            +---- Vout
+            |
+         .-----.
+         | Rout|
+         '-----'
+            |
+           GND
+
+
+properties:
+  compatible:
+    const: voltage-divider
+
+  io-channels:
+    maxItems: 1
+    description: |
+      Channel node of a voltage io-channel.
+
+  output-ohms:
+    description:
+      Resistance Rout over which the output voltage is measured. See full-ohms.
+
+  full-ohms:
+    description:
+      Resistance R + Rout for the full divider. The io-channel is scaled by
+      the Rout / (R + Rout) quotient.
+
+required:
+  - compatible
+  - io-channels
+  - output-ohms
+  - full-ohms
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+    /*
+     * The system voltage is circa 12V, but divided down with a 22/222
+     * voltage divider (R = 200 Ohms, Rout = 22 Ohms) and fed to an ADC.
+     */
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        maxadc: adc@0 {
+            compatible = "maxim,max1027";
+            reg = <0>;
+            #io-channel-cells = <1>;
+            interrupt-parent = <&gpio5>;
+            interrupts = <15 IRQ_TYPE_EDGE_RISING>;
+            spi-max-frequency = <1000000>;
+        };
+    };
+    sysv {
+        compatible = "voltage-divider";
+        io-channels = <&maxadc 1>;
+
+        /* Scale the system voltage by 22/222 to fit the ADC range. */
+        output-ohms = <22>;
+        full-ohms = <222>; /* 200 + 22 */
+    };
+...