net: dsa: b53: mmap: add phy ops

Implement phy_read16() and phy_write16() ops for B53 MMAP to avoid accessing
B53_PORT_MII_PAGE registers which hangs the device.
This access should be done through the MDIO Mux bus controller.
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/b53/b53_mmap.c

@@ -216,6 +216,18 @@ static int b53_mmap_write64(struct b53_device *dev, u8 page, u8 reg,
 	return 0;
 }
 
+static int b53_mmap_phy_read16(struct b53_device *dev, int addr, int reg,
+			       u16 *value)
+{
+	return -EIO;
+}
+
+static int b53_mmap_phy_write16(struct b53_device *dev, int addr, int reg,
+				u16 value)
+{
+	return -EIO;
+}
+
 static const struct b53_io_ops b53_mmap_ops = {
 	.read8 = b53_mmap_read8,
 	.read16 = b53_mmap_read16,
@@ -227,6 +239,8 @@ static const struct b53_io_ops b53_mmap_ops = {
 	.write32 = b53_mmap_write32,
 	.write48 = b53_mmap_write48,
 	.write64 = b53_mmap_write64,
+	.phy_read16 = b53_mmap_phy_read16,
+	.phy_write16 = b53_mmap_phy_write16,
 };
 
 static int b53_mmap_probe_of(struct platform_device *pdev,