net: dsa: b53: add BCM63268 RGMII configuration

BCM63268 requires special RGMII configuration to work.
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/dsa/b53/b53_common.c

@@ -1240,8 +1240,12 @@ static void b53_adjust_63xx_rgmii(struct dsa_switch *ds, int port,
 		break;
 	}
 
-	if (port != dev->imp_port)
+	if (port != dev->imp_port) {
+		if (is63268(dev))
+			rgmii_ctrl |= RGMII_CTRL_MII_OVERRIDE;
+
 		rgmii_ctrl |= RGMII_CTRL_ENABLE_GMII;
+	}
 
 	b53_write8(dev, B53_CTRL_PAGE, off, rgmii_ctrl);
 

drivers/net/dsa/b53/b53_regs.h

@@ -138,6 +138,7 @@
 
 #define B53_RGMII_CTRL_IMP		0x60
 #define   RGMII_CTRL_ENABLE_GMII	BIT(7)
+#define   RGMII_CTRL_MII_OVERRIDE	BIT(6)
 #define   RGMII_CTRL_TIMING_SEL		BIT(2)
 #define   RGMII_CTRL_DLL_RXC		BIT(1)
 #define   RGMII_CTRL_DLL_TXC		BIT(0)