openwrt/target/linux/generic/pending-4.19/735-net-phy-at803x-fix-at8033-sgmii-mode.patch

From: Roman Yeryomin <roman@advem.lv>
Subject: kernel: add at803x fix for sgmii mode

Some (possibly broken) bootloaders incorreclty initialize at8033
phy. This patch enables sgmii autonegotiation mode.

[john@phrozen.org: felix added this to his upstream queue]

Signed-off-by: Roman Yeryomin <roman@advem.lv>
---
 drivers/net/phy/at803x.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

--- a/drivers/net/phy/at803x.c
+++ b/drivers/net/phy/at803x.c
@@ -44,6 +44,7 @@
 #define AT803X_FUNC_DATA			0x4003
 #define AT803X_REG_CHIP_CONFIG			0x1f
 #define AT803X_BT_BX_REG_SEL			0x8000
+#define AT803X_SGMII_ANEG_EN			0x1000
 
 #define AT803X_DEBUG_ADDR			0x1D
 #define AT803X_DEBUG_DATA			0x1E
@@ -252,6 +253,27 @@ static int at803x_probe(struct phy_devic
 static int at803x_config_init(struct phy_device *phydev)
 {
 	int ret;
+	u32 v;
+
+	if (phydev->drv->phy_id == ATH8031_PHY_ID &&
+		phydev->interface == PHY_INTERFACE_MODE_SGMII)
+	{
+		v = phy_read(phydev, AT803X_REG_CHIP_CONFIG);
+		/* select SGMII/fiber page */
+		ret = phy_write(phydev, AT803X_REG_CHIP_CONFIG,
+						v & ~AT803X_BT_BX_REG_SEL);
+		if (ret)
+			return ret;
+		/* enable SGMII autonegotiation */
+		ret = phy_write(phydev, MII_BMCR, AT803X_SGMII_ANEG_EN);
+		if (ret)
+			return ret;
+		/* select copper page */
+		ret = phy_write(phydev, AT803X_REG_CHIP_CONFIG,
+						v | AT803X_BT_BX_REG_SEL);
+		if (ret)
+			return ret;
+	}
 
 	ret = genphy_config_init(phydev);
 	if (ret < 0)