dt-bindings:iio:proximity:ams,as3935 yaml conversion

A straight forward conversion of this binding. I have added
a maximum SPI frequency from the datasheet.
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Matt Ranostay <matt.ranostay@konsulko.com>
Link: https://lore.kernel.org/r/20201031134110.724233-12-jic23@kernel.org

Documentation/devicetree/bindings/iio/proximity/ams,as3935.yaml

+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/proximity/ams,as3935.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Austrian Microsystems AS3935 Franklin lightning sensor
+
+maintainers:
+  - Matt Ranostay <matt.ranostay@konsulko.com>
+
+description:
+  This lightening distance sensor uses an I2C or SPI interface. The
+  binding currently only covers the SPI option.
+
+properties:
+  compatible:
+    const: ams,as3935
+
+  reg:
+    maxItems: 1
+
+  spi-max-frequency:
+    maximum: 2000000
+
+  spi-cpha: true
+
+  interrupts:
+    maxItems: 1
+
+  ams,tuning-capacitor-pf:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      Calibration tuning capacitor stepping value. This will require using
+      the calibration data from the manufacturer.
+    minimum: 0
+    maximum: 120
+
+  ams,nflwdth:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      Set the noise and watchdog threshold register on startup. This will
+      need to set according to the noise from the MCU board, and possibly
+      the local environment. Refer to the datasheet for the threshold settings.
+
+required:
+  - compatible
+  - reg
+  - spi-cpha
+  - interrupts
+
+additionalProperties: false
+
+examples:
+  - |
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+    lightning@0 {
+            compatible = "ams,as3935";
+            reg = <0>;
+            spi-max-frequency = <400000>;
+            spi-cpha;
+            interrupt-parent = <&gpio1>;
+            interrupts = <16 1>;
+            ams,tuning-capacitor-pf = <80>;
+            ams,nflwdth = <0x44>;
+        };
+    };
+...

Documentation/devicetree/bindings/iio/proximity/as3935.txt

-Austrian Microsystems AS3935 Franklin lightning sensor device driver
-
-Required properties:
-	- compatible: must be "ams,as3935"
-	- reg: SPI chip select number for the device
-	- spi-max-frequency: specifies maximum SPI clock frequency
-	- spi-cpha: SPI Mode 1. Refer to spi/spi-bus.txt for generic SPI
-	slave node bindings.
-	- interrupts : the sole interrupt generated by the device
-
-	Refer to interrupt-controller/interrupts.txt for generic
-	interrupt client node bindings.
-
-Optional properties:
-	- ams,tuning-capacitor-pf: Calibration tuning capacitor stepping
-	  value 0 - 120pF. This will require using the calibration data from
-	  the manufacturer.
-	- ams,nflwdth: Set the noise and watchdog threshold register on
-	  startup. This will need to set according to the noise from the
-	  MCU board, and possibly the local environment. Refer to the
-	  datasheet for the threshold settings.
-
-Example:
-
-as3935@0 {
-	compatible = "ams,as3935";
-	reg = <0>;
-	spi-max-frequency = <400000>;
-	spi-cpha;
-	interrupt-parent = <&gpio1>;
-	interrupts = <16 1>;
-	ams,tuning-capacitor-pf = <80>;
-	ams,nflwdth = <0x44>;
-};