dt-bindings: iio: adc: Add the NXP SAR ADC for s32g2/3 platforms

The s32g2 and s32g3 NXP platforms have two instances of a Successive
Approximation Register ADC. It supports the raw, trigger and scan
modes which involves the DMA. Add their descriptions.

Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Documentation/devicetree/bindings/iio/adc/nxp,s32g2-sar-adc.yaml

@@ -0,0 +1,63 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/adc/nxp,s32g2-sar-adc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: NXP Successive Approximation ADC
+
+description:
+  The NXP SAR ADC provides fast and accurate analog-to-digital
+  conversion using the Successive Approximation Register (SAR) method.
+  It has 12-bit resolution with 8 input channels. Conversions can be
+  launched in software or using hardware triggers. It supports
+  continuous and one-shot modes with separate registers.
+
+maintainers:
+  - Daniel Lezcano <daniel.lezcano@kernel.org>
+
+properties:
+  compatible:
+    oneOf:
+      - const: nxp,s32g2-sar-adc
+      - items:
+          - const: nxp,s32g3-sar-adc
+          - const: nxp,s32g2-sar-adc
+
+  reg:
+    maxItems: 1
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    maxItems: 1
+
+  dmas:
+    maxItems: 1
+
+  dma-names:
+    const: rx
+
+required:
+  - compatible
+  - reg
+  - interrupts
+  - clocks
+  - dmas
+  - dma-names
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+
+    adc@401f8000 {
+        compatible = "nxp,s32g2-sar-adc";
+        reg = <0x401f8000 0x1000>;
+        interrupts = <GIC_SPI 70 IRQ_TYPE_LEVEL_HIGH>;
+        clocks = <&clks 0x41>;
+        dmas = <&edma0 0 32>;
+        dma-names = "rx";
+    };