[PATCH] phy: rockchip: inno-usb2: fix phy reg=0 case

[Eugen Hristev]

The support for #address-cells=2 has a loophole: if the reg is actually 0,
but the #address-cells is actually 1, like in such case below:

syscon {
        #address-cells = <1>;

        phy {
                reg = <0 0x10>;
        };
};

then the second u32 of the 'reg' is the size, not the address.

The code should check for the parent's #address-cells value, and not
assume that if the first u32 is 0, then the #address-cells is 2, and the
reg property is something like
        reg = <0 0xff00 0x10>;

Fixed this by looking for the #address-cells value and retrieving the
reg address only if this is ==2.
To avoid breaking anything I also kept the check `if reg==0` as some DT's
may have a wrong #address-cells as parent and even if this commit is
correct, it might break the existing wrong device-trees.

Fixes: d538efb9adcf ("phy: rockchip: inno-usb2: Add support #address_cells = 2")
Signed-off-by: Eugen Hristev <eugen.hris...@collabora.com>
---
 drivers/phy/rockchip/phy-rockchip-inno-usb2.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/phy/rockchip/phy-rockchip-inno-usb2.c 
b/drivers/phy/rockchip/phy-rockchip-inno-usb2.c
index 22e2797eea28..e5e02b6765b1 100644
--- a/drivers/phy/rockchip/phy-rockchip-inno-usb2.c
+++ b/drivers/phy/rockchip/phy-rockchip-inno-usb2.c
@@ -186,7 +186,7 @@ static int rockchip_usb2phy_probe(struct udevice *dev)
        }
 
        /* support address_cells=2 */
-       if (reg == 0) {
+       if (dev_read_addr_cells(dev) == 2 && reg == 0) {
                if (ofnode_read_u32_index(dev_ofnode(dev), "reg", 1, &reg)) {
                        dev_err(dev, "%s must have reg[1]\n",
                                ofnode_get_name(dev_ofnode(dev)));
-- 
2.34.1