net: dsa: mt7530: support the 7530 switch on the Mediatek MT7621 SoC

The MediaTek MT7621 SoC device contains a 7530 switch, and the existing
linux kernel 7530 DSA switch driver can be used with it.

The bulk of the changes required stem from the 7621 having different
regulator and pad setup. The existing setup of these in the 7530
driver appears to be very specific to its implemtation in the Mediatek
7623 SoC. (Not entirely surprising given the 7623 is a quad core ARM
based SoC, and the 7621 is a dual core, dual thread MIPS based SoC).

Create a new devicetree type, "mediatek,mt7621", to support the 7530
switch in the 7621 SoC. There appears to be no usable ID register to
distinguish it from a 7530 in other hardware at runtime. This is used
to carry out the appropriate configuration and setup.
Signed-off-by: Greg Ungerer <gerg@kernel.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Sean Wang <sean.wang@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/mt7530.c

@@ -621,17 +621,19 @@ static void mt7530_adjust_link(struct dsa_switch *ds, int port,
 	struct mt7530_priv *priv = ds->priv;
 
 	if (phy_is_pseudo_fixed_link(phydev)) {
-		dev_dbg(priv->dev, "phy-mode for master device = %x\n",
-			phydev->interface);
-
-		/* Setup TX circuit incluing relevant PAD and driving */
-		mt7530_pad_clk_setup(ds, phydev->interface);
-
-		/* Setup RX circuit, relevant PAD and driving on the host
-		 * which must be placed after the setup on the device side is
-		 * all finished.
-		 */
-		mt7623_pad_clk_setup(ds);
+		if (priv->id == ID_MT7530) {
+			dev_dbg(priv->dev, "phy-mode for master device = %x\n",
+				phydev->interface);
+
+			/* Setup TX circuit incluing relevant PAD and driving */
+			mt7530_pad_clk_setup(ds, phydev->interface);
+
+			/* Setup RX circuit, relevant PAD and driving on the
+			 * host which must be placed after the setup on the
+			 * device side is all finished.
+			 */
+			mt7623_pad_clk_setup(ds);
+		}
 	} else {
 		u16 lcl_adv = 0, rmt_adv = 0;
 		u8 flowctrl;
@@ -687,6 +689,10 @@ mt7530_cpu_port_enable(struct mt7530_priv *priv,
 	/* Unknown unicast frame fordwarding to the cpu port */
 	mt7530_set(priv, MT7530_MFC, UNU_FFP(BIT(port)));
 
+	/* Set CPU port number */
+	if (priv->id == ID_MT7621)
+		mt7530_rmw(priv, MT7530_MFC, CPU_MASK, CPU_EN | CPU_PORT(port));
+
 	/* CPU port gets connected to all user ports of
 	 * the switch
 	 */
@@ -1219,24 +1225,27 @@ mt7530_setup(struct dsa_switch *ds)
 	 * as two netdev instances.
 	 */
 	dn = ds->ports[MT7530_CPU_PORT].master->dev.of_node->parent;
-	priv->ethernet = syscon_node_to_regmap(dn);
-	if (IS_ERR(priv->ethernet))
-		return PTR_ERR(priv->ethernet);
 
-	regulator_set_voltage(priv->core_pwr, 1000000, 1000000);
-	ret = regulator_enable(priv->core_pwr);
-	if (ret < 0) {
-		dev_err(priv->dev,
-			"Failed to enable core power: %d\n", ret);
-		return ret;
-	}
+	if (priv->id == ID_MT7530) {
+		priv->ethernet = syscon_node_to_regmap(dn);
+		if (IS_ERR(priv->ethernet))
+			return PTR_ERR(priv->ethernet);
+
+		regulator_set_voltage(priv->core_pwr, 1000000, 1000000);
+		ret = regulator_enable(priv->core_pwr);
+		if (ret < 0) {
+			dev_err(priv->dev,
+				"Failed to enable core power: %d\n", ret);
+			return ret;
+		}
 
-	regulator_set_voltage(priv->io_pwr, 3300000, 3300000);
-	ret = regulator_enable(priv->io_pwr);
-	if (ret < 0) {
-		dev_err(priv->dev, "Failed to enable io pwr: %d\n",
-			ret);
-		return ret;
+		regulator_set_voltage(priv->io_pwr, 3300000, 3300000);
+		ret = regulator_enable(priv->io_pwr);
+		if (ret < 0) {
+			dev_err(priv->dev, "Failed to enable io pwr: %d\n",
+				ret);
+			return ret;
+		}
 	}
 
 	/* Reset whole chip through gpio pin or memory-mapped registers for
@@ -1326,6 +1335,13 @@ static const struct dsa_switch_ops mt7530_switch_ops = {
 	.port_vlan_del		= mt7530_port_vlan_del,
 };
 
+static const struct of_device_id mt7530_of_match[] = {
+	{ .compatible = "mediatek,mt7621", .data = (void *)ID_MT7621, },
+	{ .compatible = "mediatek,mt7530", .data = (void *)ID_MT7530, },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, mt7530_of_match);
+
 static int
 mt7530_probe(struct mdio_device *mdiodev)
 {
@@ -1356,13 +1372,21 @@ mt7530_probe(struct mdio_device *mdiodev)
 		}
 	}
 
-	priv->core_pwr = devm_regulator_get(&mdiodev->dev, "core");
-	if (IS_ERR(priv->core_pwr))
-		return PTR_ERR(priv->core_pwr);
+	/* Get the hardware identifier from the devicetree node.
+	 * We will need it for some of the clock and regulator setup.
+	 */
+	priv->id = (unsigned int)(unsigned long)
+		of_device_get_match_data(&mdiodev->dev);
 
-	priv->io_pwr = devm_regulator_get(&mdiodev->dev, "io");
-	if (IS_ERR(priv->io_pwr))
-		return PTR_ERR(priv->io_pwr);
+	if (priv->id == ID_MT7530) {
+		priv->core_pwr = devm_regulator_get(&mdiodev->dev, "core");
+		if (IS_ERR(priv->core_pwr))
+			return PTR_ERR(priv->core_pwr);
+
+		priv->io_pwr = devm_regulator_get(&mdiodev->dev, "io");
+		if (IS_ERR(priv->io_pwr))
+			return PTR_ERR(priv->io_pwr);
+	}
 
 	/* Not MCM that indicates switch works as the remote standalone
 	 * integrated circuit so the GPIO pin would be used to complete
@@ -1408,12 +1432,6 @@ mt7530_remove(struct mdio_device *mdiodev)
 	mutex_destroy(&priv->reg_mutex);
 }
 
-static const struct of_device_id mt7530_of_match[] = {
-	{ .compatible = "mediatek,mt7530" },
-	{ /* sentinel */ },
-};
-MODULE_DEVICE_TABLE(of, mt7530_of_match);
-
 static struct mdio_driver mt7530_mdio_driver = {
 	.probe  = mt7530_probe,
 	.remove = mt7530_remove,

drivers/net/dsa/mt7530.h

@@ -19,6 +19,11 @@
 #define MT7530_NUM_FDB_RECORDS		2048
 #define MT7530_ALL_MEMBERS		0xff
 
+enum {
+	ID_MT7530 = 0,
+	ID_MT7621 = 1,
+};
+
 #define	NUM_TRGMII_CTRL			5
 
 #define TRGMII_BASE(x)			(0x10000 + (x))
@@ -36,6 +41,9 @@
 #define  UNM_FFP(x)			(((x) & 0xff) << 16)
 #define  UNU_FFP(x)			(((x) & 0xff) << 8)
 #define  UNU_FFP_MASK			UNU_FFP(~0)
+#define  CPU_EN				BIT(7)
+#define  CPU_PORT(x)			((x) << 4)
+#define  CPU_MASK			(0xf << 4)
 
 /* Registers for address table access */
 #define MT7530_ATA1			0x74
@@ -430,6 +438,7 @@ struct mt7530_priv {
 	struct regulator	*core_pwr;
 	struct regulator	*io_pwr;
 	struct gpio_desc	*reset;
+	unsigned int		id;
 	bool			mcm;
 
 	struct mt7530_port	ports[MT7530_NUM_PORTS];