arm64: dts: ls1028a-rdb: Add iio-hwmon compatibility table

[Martyn Welch]

The ls1028ardb uses the TI ina220 power monitor. This device has an IIO and
hwmon drivers, but can't be used with both at the same time. To enable us
to utilise the iio framework, but also access power information via the
hwmon framework, add an iio-hwmon map. This allows the IIO driver to be
used for the ina220, with the iio-hwmon driver mapping the data from the
IIO framework into hwmon.

Signed-off-by: Martyn Welch <martyn.welch@xxxxxxxxxxxxx>
---
 arch/arm64/boot/dts/freescale/fsl-ls1028a-rdb.dts | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/freescale/fsl-ls1028a-rdb.dts b/arch/arm64/boot/dts/freescale/fsl-ls1028a-rdb.dts
index ecd2c1e..b062de5 100644
--- a/arch/arm64/boot/dts/freescale/fsl-ls1028a-rdb.dts
+++ b/arch/arm64/boot/dts/freescale/fsl-ls1028a-rdb.dts
@@ -94,6 +94,12 @@ simple-audio-card,codec {
 			system-clock-frequency = <25000000>;
 		};
 	};
+
+	iio-hwmon {
+		compatible = "iio-hwmon";
+		io-channels = <&ina220 0>, <&ina220 1>,
+			<&ina220 2>, <&ina220 3>;
+	};
 };
 
 &can0 {
@@ -222,8 +228,9 @@ i2c@2 {
 			#size-cells = <0>;
 			reg = <0x02>;
 
-			current-monitor@40 {
+			ina220: current-monitor@40 {
 				compatible = "ti,ina220";
+				#io-channel-cells = <1>;
 				reg = <0x40>;
 				shunt-resistor = <500>;
 			};