ath79: ag71xx: apply interface mode to MII0/1_CTRL on ar71xx/ar913x

We currently don't have any code configuring interface mode in ath79,
meaning that we relies on bootloader to set the correct interface mode.

This patch added code to set interface correctly so that everything works
even if bootloader configures it wrong.(e.g. on WNDR3800 u-boot set
the second GMAC mode to RMII but it should be RGMII.)

Introduced "qca,mac-idx" for the difference in MII_CTRL register value.

Signed-off-by: Chuanhong Guo <gch981213@gmail.com>

target/linux/ath79/dts/ar7100.dtsi

@@ -182,6 +182,7 @@
 
 	resets = <&rst 9>;
 	reset-names = "mac";
+	qca,mac-idx = <0>;
 };
 
 &mdio1 {
@@ -201,4 +202,5 @@
 
 	resets = <&rst 13>;
 	reset-names = "mac";
+	qca,mac-idx = <1>;
 };

target/linux/ath79/dts/ar9132.dtsi

@@ -193,4 +193,5 @@
 	pll-handle = <&pll>;
 	resets = <&rst 9>;
 	reset-names = "mac";
+	qca,mac-idx = <0>;
 };

target/linux/ath79/files/drivers/net/ethernet/atheros/ag71xx/ag71xx.h

@@ -154,6 +154,8 @@ struct ag71xx {
 	struct ag71xx_ring	rx_ring ____cacheline_aligned;
 	struct ag71xx_ring	tx_ring ____cacheline_aligned;
 
+	int			mac_idx;
+
 	u16			desc_pktlen_mask;
 	u16			rx_buf_size;
 	u8			rx_buf_offset;

target/linux/ath79/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c

@@ -529,6 +529,60 @@ static void ath79_set_pll(struct ag71xx *ag)
 	udelay(100);
 }
 
+static void ath79_mii_ctrl_set_if(struct ag71xx *ag, unsigned int mii_if)
+{
+	u32 t;
+
+	t = __raw_readl(ag->mii_base);
+	t &= ~(AR71XX_MII_CTRL_IF_MASK);
+	t |= (mii_if & AR71XX_MII_CTRL_IF_MASK);
+	__raw_writel(t, ag->mii_base);
+}
+
+static void ath79_mii0_ctrl_set_if(struct ag71xx *ag)
+{
+	unsigned int mii_if;
+
+	switch (ag->phy_if_mode) {
+	case PHY_INTERFACE_MODE_MII:
+		mii_if = AR71XX_MII0_CTRL_IF_MII;
+		break;
+	case PHY_INTERFACE_MODE_GMII:
+		mii_if = AR71XX_MII0_CTRL_IF_GMII;
+		break;
+	case PHY_INTERFACE_MODE_RGMII:
+		mii_if = AR71XX_MII0_CTRL_IF_RGMII;
+		break;
+	case PHY_INTERFACE_MODE_RMII:
+		mii_if = AR71XX_MII0_CTRL_IF_RMII;
+		break;
+	default:
+		WARN(1, "Impossible PHY mode defined.\n");
+		return;
+	}
+
+	ath79_mii_ctrl_set_if(ag, mii_if);
+}
+
+static void ath79_mii1_ctrl_set_if(struct ag71xx *ag)
+{
+	unsigned int mii_if;
+
+	switch (ag->phy_if_mode) {
+	case PHY_INTERFACE_MODE_RMII:
+		mii_if = AR71XX_MII1_CTRL_IF_RMII;
+		break;
+	case PHY_INTERFACE_MODE_RGMII:
+		mii_if = AR71XX_MII1_CTRL_IF_RGMII;
+		break;
+	default:
+		WARN(1, "Impossible PHY mode defined.\n");
+		return;
+	}
+
+	ath79_mii_ctrl_set_if(ag, mii_if);
+}
+
 static void ath79_mii_ctrl_set_speed(struct ag71xx *ag)
 {
 	unsigned int mii_speed;
@@ -1427,6 +1481,20 @@ static int ag71xx_probe(struct platform_device *pdev)
 		goto err_free;
 	}
 
+	if (of_property_read_u32(np, "qca,mac-idx", &ag->mac_idx))
+		ag->mac_idx = -1;
+	if (ag->mii_base)
+		switch (ag->mac_idx) {
+		case 0:
+			ath79_mii0_ctrl_set_if(ag);
+			break;
+		case 1:
+			ath79_mii1_ctrl_set_if(ag);
+			break;
+		default:
+			break;
+		}
+
 	netif_napi_add(dev, &ag->napi, ag71xx_poll, AG71XX_NAPI_WEIGHT);
 
 	ag71xx_wr(ag, AG71XX_REG_MAC_CFG1, 0);