dt-bindings: net: wireless: mt76: document bindings for MT7622

MT7622 is a SoC that includes a 2.4 GHz 4x4 802.11n WMAC. Its
feature set is comparable to a MT7615 chip, but limited to 2.4 GHz.
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Felix Fietkau <nbd@nbd.name>

Documentation/devicetree/bindings/net/wireless/mediatek,mt76.txt

@@ -4,13 +4,21 @@ This node provides properties for configuring the MediaTek mt76xx wireless
 device. The node is expected to be specified as a child node of the PCI
 controller to which the wireless chip is connected.
 
-Alternatively, it can specify the wireless part of the MT7628/MT7688 SoC.
-For SoC, use the compatible string "mediatek,mt7628-wmac" and the following
-properties:
+Alternatively, it can specify the wireless part of the MT7628/MT7688 or
+MT7622 SoC. For SoC, use the following compatible strings:
+
+compatible:
+- "mediatek,mt7628-wmac" for MT7628/MT7688
+- "mediatek,mt7622-wmac" for MT7622
 
+properties:
 - reg: Address and length of the register set for the device.
 - interrupts: Main device interrupt
 
+MT7622 specific properties:
+- power-domains: phandle to the power domain that the WMAC is part of
+- mediatek,infracfg: phandle to the infrastructure bus fabric syscon node
+
 Optional properties:
 
 - ieee80211-freq-limit: See ieee80211.txt
@@ -53,3 +61,15 @@ wmac: wmac@10300000 {
 
 	mediatek,mtd-eeprom = <&factory 0x0000>;
 };
+
+MT7622 example:
+
+wmac: wmac@18000000 {
+	compatible = "mediatek,mt7622-wmac";
+	reg = <0 0x18000000 0 0x100000>;
+	interrupts = <GIC_SPI 211 IRQ_TYPE_LEVEL_LOW>;
+
+	mediatek,infracfg = <&infracfg>;
+
+	power-domains = <&scpsys MT7622_POWER_DOMAIN_WB>;
+};