net: mediatek: Add MT7621 TRGMII mode support

index f27efe4110cc..066712f2e985 100644
@@ -134,6 +134,28 @@ static int mtk_mdio_read(struct mii_bus *bus, int phy_addr, int phy_reg)
 	return _mtk_mdio_read(eth, phy_addr, phy_reg);
 }
 
+static int mt7621_gmac0_rgmii_adjust(struct mtk_eth *eth,
+				     phy_interface_t interface)
+{
+	u32 val;
+
+	/* Check DDR memory type. Currently DDR2 is not supported. */
+	regmap_read(eth->ethsys, ETHSYS_SYSCFG, &val);
+	if (val & SYSCFG_DRAM_TYPE_DDR2) {
+		dev_err(eth->dev,
+			"TRGMII mode with DDR2 memory is not supported!\n");
+		return -EOPNOTSUPP;
+	}
+
+	val = (interface == PHY_INTERFACE_MODE_TRGMII) ?
+		ETHSYS_TRGMII_MT7621_DDR_PLL : 0;
+
+	regmap_update_bits(eth->ethsys, ETHSYS_CLKCFG0,
+			   ETHSYS_TRGMII_MT7621_MASK, val);
+
+	return 0;
+}
+
 static void mtk_gmac0_rgmii_adjust(struct mtk_eth *eth, int speed)
 {
 	u32 val;

@@ -183,9 +205,17 @@ static void mtk_phy_link_adjust(struct net_device *dev)
 		break;
 	}
 
-	if (MTK_HAS_CAPS(mac->hw->soc->caps, MTK_GMAC1_TRGMII) &&
-	    !mac->id && !mac->trgmii)
-		mtk_gmac0_rgmii_adjust(mac->hw, dev->phydev->speed);
+	if (MTK_HAS_CAPS(mac->hw->soc->caps, MTK_GMAC1_TRGMII) && !mac->id) {
+		if (MTK_HAS_CAPS(mac->hw->soc->caps, MTK_TRGMII_MT7621_CLK)) {
+			if (mt7621_gmac0_rgmii_adjust(mac->hw,
+						      dev->phydev->interface))
+				return;
+		} else {
+			if (!mac->trgmii)
+				mtk_gmac0_rgmii_adjust(mac->hw,
+						       dev->phydev->speed);
+		}
+	}
 
 	if (dev->phydev->link)
 		mcr |= MAC_MCR_FORCE_LINK;

@@ -2607,7 +2637,7 @@ static const struct mtk_soc_data mt2701_data = {
 };
 
 static const struct mtk_soc_data mt7621_data = {
-	.caps = MTK_SHARED_INT,
+	.caps = MT7621_CAPS,
 	.required_clks = MT7621_CLKS_BITMAP,
 	.required_pctl = false,
 };

index 85e3144f1af5..876ce6798709 100644
@@ -363,6 +363,10 @@
 #define MT7622_ETH		7622
 #define MT7621_ETH		7621
 
+/* ethernet system control register */
+#define ETHSYS_SYSCFG		0x10
+#define SYSCFG_DRAM_TYPE_DDR2	BIT(4)
+
 /* ethernet subsystem config register */
 #define ETHSYS_SYSCFG0		0x14
 #define SYSCFG0_GE_MASK		0x3

@@ -377,6 +381,9 @@
 /* ethernet subsystem clock register */
 #define ETHSYS_CLKCFG0		0x2c
 #define ETHSYS_TRGMII_CLK_SEL362_5	BIT(11)
+#define ETHSYS_TRGMII_MT7621_MASK	(BIT(5) | BIT(6))
+#define ETHSYS_TRGMII_MT7621_APLL	BIT(6)
+#define ETHSYS_TRGMII_MT7621_DDR_PLL	BIT(5)
 
 /* ethernet reset control register */
 #define ETHSYS_RSTCTRL		0x34

@@ -616,6 +623,7 @@ enum mtk_eth_path {
 #define MTK_SHARED_SGMII		BIT(7)
 #define MTK_HWLRO			BIT(8)
 #define MTK_SHARED_INT			BIT(9)
+#define MTK_TRGMII_MT7621_CLK		BIT(10)
 
 /* Supported path present on SoCs */
 #define MTK_PATH_BIT(x)         BIT((x) + 10)

@@ -667,6 +675,9 @@ enum mtk_eth_path {
 
 #define MTK_HAS_CAPS(caps, _x)		(((caps) & (_x)) == (_x))
 
+#define MT7621_CAPS  (MTK_GMAC1_RGMII | MTK_GMAC1_TRGMII | \
+		      MTK_GMAC2_RGMII | MTK_SHARED_INT | MTK_TRGMII_MT7621_CLK)
+
 #define MT7622_CAPS  (MTK_GMAC1_RGMII | MTK_GMAC1_SGMII | MTK_GMAC2_RGMII | \
 		      MTK_GMAC2_SGMII | MTK_GDM1_ESW | \
 		      MTK_MUX_GDM1_TO_GMAC1_ESW | \

index c7d352da5448..3181e95586d6 100644
@@ -428,24 +428,48 @@ static int
 mt7530_pad_clk_setup(struct dsa_switch *ds, int mode)
 {
 	struct mt7530_priv *priv = ds->priv;
-	u32 ncpo1, ssc_delta, trgint, i;
+	u32 ncpo1, ssc_delta, trgint, i, xtal;
+
+	xtal = mt7530_read(priv, MT7530_MHWTRAP) & HWTRAP_XTAL_MASK;
+
+	if (xtal == HWTRAP_XTAL_20MHZ) {
+		dev_err(priv->dev,
+			"%s: MT7530 with a 20MHz XTAL is not supported!\n",
+			__func__);
+		return -EINVAL;
+	}
 
 	switch (mode) {
 	case PHY_INTERFACE_MODE_RGMII:
 		trgint = 0;
+		/* PLL frequency: 125MHz */
 		ncpo1 = 0x0c80;
-		ssc_delta = 0x87;
 		break;
 	case PHY_INTERFACE_MODE_TRGMII:
 		trgint = 1;
-		ncpo1 = 0x1400;
-		ssc_delta = 0x57;
+		if (priv->id == ID_MT7621) {
+			/* PLL frequency: 150MHz: 1.2GBit */
+			if (xtal == HWTRAP_XTAL_40MHZ)
+				ncpo1 = 0x0780;
+			if (xtal == HWTRAP_XTAL_25MHZ)
+				ncpo1 = 0x0a00;
+		} else { /* PLL frequency: 250MHz: 2.0Gbit */
+			if (xtal == HWTRAP_XTAL_40MHZ)
+				ncpo1 = 0x0c80;
+			if (xtal == HWTRAP_XTAL_25MHZ)
+				ncpo1 = 0x1400;
+		}
 		break;
 	default:
 		dev_err(priv->dev, "xMII mode %d not supported\n", mode);
 		return -EINVAL;
 	}
 
+	if (xtal == HWTRAP_XTAL_25MHZ)
+		ssc_delta = 0x57;
+	else
+		ssc_delta = 0x87;
+
 	mt7530_rmw(priv, MT7530_P6ECR, P6_INTF_MODE_MASK,
 		   P6_INTF_MODE(trgint));
 

@@ -507,7 +531,9 @@ mt7530_pad_clk_setup(struct dsa_switch *ds, int mode)
 			mt7530_rmw(priv, MT7530_TRGMII_RD(i),
 				   RD_TAP_MASK, RD_TAP(16));
 	else
-		mt7623_trgmii_set(priv, GSW_INTF_MODE, INTF_MODE_TRGMII);
+		if (priv->id != ID_MT7621)
+			mt7623_trgmii_set(priv, GSW_INTF_MODE,
+					  INTF_MODE_TRGMII);
 
 	return 0;
 }

@@ -613,13 +639,13 @@ static void mt7530_adjust_link(struct dsa_switch *ds, int port,
 	struct mt7530_priv *priv = ds->priv;
 
 	if (phy_is_pseudo_fixed_link(phydev)) {
-		if (priv->id == ID_MT7530) {
-			dev_dbg(priv->dev, "phy-mode for master device = %x\n",
-				phydev->interface);
+		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 TX circuit incluing relevant PAD and driving */
+		mt7530_pad_clk_setup(ds, phydev->interface);
 
+		if (priv->id == ID_MT7530) {
 			/* Setup RX circuit, relevant PAD and driving on the
 			 * host which must be placed after the setup on the
 			 * device side is all finished.

index 4331429969fa..bfac90f48102 100644
@@ -244,6 +244,10 @@ enum mt7530_vlan_port_attr {
 
 /* Register for hw trap status */
 #define MT7530_HWTRAP			0x7800
+#define  HWTRAP_XTAL_MASK		(BIT(10) | BIT(9))
+#define  HWTRAP_XTAL_25MHZ		(BIT(10) | BIT(9))
+#define  HWTRAP_XTAL_40MHZ		(BIT(10))
+#define  HWTRAP_XTAL_20MHZ		(BIT(9))
 
 /* Register for hw trap modification */
 #define MT7530_MHWTRAP			0x7804