phy: phy-rockchip-inno-usb2: support #address_cells = 2

New Rockchip devices have the usb phy nodes as standalone devices.
These nodes have register nodes with #address_cells = 2, but only use 32
bit addresses.

Adjust the driver to check if the returned address is "0", and adjust
the index in that case.

Signed-off-by: Peter Geis <pgwipeout@gmail.com>
Tested-by: Michael Riesch <michael.riesch@wolfvision.net>
Link: https://lore.kernel.org/r/20211215210252.120923-4-pgwipeout@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
diff --git a/drivers/phy/rockchip/phy-rockchip-inno-usb2.c b/drivers/phy/rockchip/phy-rockchip-inno-usb2.c
index 9f95b58..fac390e 100644
--- a/drivers/phy/rockchip/phy-rockchip-inno-usb2.c
+++ b/drivers/phy/rockchip/phy-rockchip-inno-usb2.c
@@ -1090,12 +1090,21 @@ static int rockchip_usb2phy_probe(struct platform_device *pdev)
 		rphy->usbgrf = NULL;
 	}
 
-	if (of_property_read_u32(np, "reg", &reg)) {
+	if (of_property_read_u32_index(np, "reg", 0, &reg)) {
 		dev_err(dev, "the reg property is not assigned in %pOFn node\n",
 			np);
 		return -EINVAL;
 	}
 
+	/* support address_cells=2 */
+	if (reg == 0) {
+		if (of_property_read_u32_index(np, "reg", 1, &reg)) {
+			dev_err(dev, "the reg property is not assigned in %pOFn node\n",
+				np);
+			return -EINVAL;
+		}
+	}
+
 	rphy->dev = dev;
 	phy_cfgs = match->data;
 	rphy->chg_state = USB_CHG_STATE_UNDEFINED;