net: dsa: mt7530: rework mt753[01]_setup

Enumerate available cpu-ports instead of using hardcoded constant.
Suggested-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/dsa/mt7530.c

@@ -2092,11 +2092,12 @@ static int
 mt7530_setup(struct dsa_switch *ds)
 {
 	struct mt7530_priv *priv = ds->priv;
+	struct device_node *dn = NULL;
 	struct device_node *phy_node;
 	struct device_node *mac_np;
 	struct mt7530_dummy_poll p;
 	phy_interface_t interface;
-	struct device_node *dn;
+	struct dsa_port *cpu_dp;
 	u32 id, val;
 	int ret, i;
 
@@ -2104,7 +2105,19 @@ mt7530_setup(struct dsa_switch *ds)
 	 * controller also is the container for two GMACs nodes representing
 	 * as two netdev instances.
 	 */
-	dn = dsa_to_port(ds, MT7530_CPU_PORT)->master->dev.of_node->parent;
+	dsa_switch_for_each_cpu_port(cpu_dp, ds) {
+		dn = cpu_dp->master->dev.of_node->parent;
+		/* It doesn't matter which CPU port is found first,
+		 * their masters should share the same parent OF node
+		 */
+		break;
+	}
+
+	if (!dn) {
+		dev_err(ds->dev, "parent OF node of DSA master not found");
+		return -EINVAL;
+	}
+
 	ds->assisted_learning_on_cpu_port = true;
 	ds->mtu_enforcement_ingress = true;
 
@@ -2266,6 +2279,7 @@ mt7531_setup(struct dsa_switch *ds)
 {
 	struct mt7530_priv *priv = ds->priv;
 	struct mt7530_dummy_poll p;
+	struct dsa_port *cpu_dp;
 	u32 val, id;
 	int ret, i;
 
@@ -2338,8 +2352,11 @@ mt7531_setup(struct dsa_switch *ds)
 				 CORE_PLL_GROUP4, val);
 
 	/* BPDU to CPU port */
-	mt7530_rmw(priv, MT7531_CFC, MT7531_CPU_PMAP_MASK,
-		   BIT(MT7530_CPU_PORT));
+	dsa_switch_for_each_cpu_port(cpu_dp, ds) {
+		mt7530_rmw(priv, MT7531_CFC, MT7531_CPU_PMAP_MASK,
+			   BIT(cpu_dp->index));
+		break;
+	}
 	mt7530_rmw(priv, MT753X_BPC, MT753X_BPDU_PORT_FW_MASK,
 		   MT753X_BPDU_CPU_ONLY);