net: dsa: mt7530: fix support for MT7531BE

There are two variants of the MT7531 switch IC which got different
features (and pins) regarding port 5:
 * MT7531AE: SGMII/1000Base-X/2500Base-X SerDes PCS
 * MT7531BE: RGMII

Moving the creation of the SerDes PCS from mt753x_setup to mt7530_probe
with commit 6de2852 ("net: dsa: mt7530: move SGMII PCS creation
to mt7530_probe function") works fine for MT7531AE which got two
instances of mtk-pcs-lynxi, however, MT7531BE requires mt7531_pll_setup
to setup clocks before the single PCS on port 6 (usually used as CPU
port) starts to work and hence the PCS creation failed on MT7531BE.

Fix this by introducing a pointer to mt7531_create_sgmii function in
struct mt7530_priv and call it again at the end of mt753x_setup like it
was before commit 6de2852 ("net: dsa: mt7530: move SGMII PCS
creation to mt7530_probe function").

Fixes: 6de2852 ("net: dsa: mt7530: move SGMII PCS creation to mt7530_probe function")
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Acked-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Link: https://lore.kernel.org/r/ZDvlLhhqheobUvOK@makrotopia.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: dangowrt

drivers/net/dsa/mt7530-mdio.c

@@ -81,14 +81,17 @@ static const struct regmap_bus mt7530_regmap_bus = {
 };
 
 static int
-mt7531_create_sgmii(struct mt7530_priv *priv)
+mt7531_create_sgmii(struct mt7530_priv *priv, bool dual_sgmii)
 {
-	struct regmap_config *mt7531_pcs_config[2];
+	struct regmap_config *mt7531_pcs_config[2] = {};
 	struct phylink_pcs *pcs;
 	struct regmap *regmap;
 	int i, ret = 0;
 
-	for (i = 0; i < 2; i++) {
+	/* MT7531AE has two SGMII units for port 5 and port 6
+	 * MT7531BE has only one SGMII unit for port 6
+	 */
+	for (i = dual_sgmii ? 0 : 1; i < 2; i++) {
 		mt7531_pcs_config[i] = devm_kzalloc(priv->dev,
 						    sizeof(struct regmap_config),
 						    GFP_KERNEL);
@@ -208,11 +211,8 @@ mt7530_probe(struct mdio_device *mdiodev)
 	if (IS_ERR(priv->regmap))
 		return PTR_ERR(priv->regmap);
 
-	if (priv->id == ID_MT7531) {
-		ret = mt7531_create_sgmii(priv);
-		if (ret)
-			return ret;
-	}
+	if (priv->id == ID_MT7531)
+		priv->create_sgmii = mt7531_create_sgmii;
 
 	return dsa_register_switch(priv->ds);
 }

drivers/net/dsa/mt7530.c

@@ -3018,6 +3018,12 @@ mt753x_setup(struct dsa_switch *ds)
 	if (ret && priv->irq)
 		mt7530_free_irq_common(priv);
 
+	if (priv->create_sgmii) {
+		ret = priv->create_sgmii(priv, mt7531_dual_sgmii_supported(priv));
+		if (ret && priv->irq)
+			mt7530_free_irq(priv);
+	}
+
 	return ret;
 }
 

drivers/net/dsa/mt7530.h

@@ -748,10 +748,10 @@ struct mt753x_info {
  *			registers
  * @p6_interface	Holding the current port 6 interface
  * @p5_intf_sel:	Holding the current port 5 interface select
- *
  * @irq:		IRQ number of the switch
  * @irq_domain:		IRQ domain of the switch irq_chip
  * @irq_enable:		IRQ enable bits, synced to SYS_INT_EN
+ * @create_sgmii:	Pointer to function creating SGMII PCS instance(s)
  */
 struct mt7530_priv {
 	struct device		*dev;
@@ -770,14 +770,14 @@ struct mt7530_priv {
 	unsigned int		p5_intf_sel;
 	u8			mirror_rx;
 	u8			mirror_tx;
-
 	struct mt7530_port	ports[MT7530_NUM_PORTS];
 	struct mt753x_pcs	pcs[MT7530_NUM_PORTS];
 	/* protect among processes for registers access*/
 	struct mutex reg_mutex;
 	int irq;
 	struct irq_domain *irq_domain;
 	u32 irq_enable;
+	int (*create_sgmii)(struct mt7530_priv *priv, bool dual_sgmii);
 };
 
 struct mt7530_hw_vlan_entry {