[PATCH] net: phy: mscc: enable MAC SerDes autonegotiation

[Raag Jadav <raagjadav@gmail.com>]

Enable MAC SerDes autonegotiation to distinguish between
1000BASE-X, SGMII and QSGMII MAC.

Signed-off-by: Raag Jadav <raagjadav@gmail.com>
---
 drivers/net/phy/mscc/mscc.h      |  2 ++
 drivers/net/phy/mscc/mscc_main.c | 24 ++++++++++++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/drivers/net/phy/mscc/mscc.h b/drivers/net/phy/mscc/mscc.h
index a50235f..366db14 100644
--- a/drivers/net/phy/mscc/mscc.h
+++ b/drivers/net/phy/mscc/mscc.h
@@ -195,6 +195,8 @@ enum rgmii_clock_delay {
 #define MSCC_PHY_EXTENDED_INT_MS_EGR	  BIT(9)
 
 /* Extended Page 3 Registers */
+#define MSCC_PHY_SERDES_PCS_CTRL	  16
+#define MSCC_PHY_SERDES_ANEG		  BIT(7)
 #define MSCC_PHY_SERDES_TX_VALID_CNT	  21
 #define MSCC_PHY_SERDES_TX_CRC_ERR_CNT	  22
 #define MSCC_PHY_SERDES_RX_VALID_CNT	  28
diff --git a/drivers/net/phy/mscc/mscc_main.c b/drivers/net/phy/mscc/mscc_main.c
index ebfeeb3..6db43a5 100644
--- a/drivers/net/phy/mscc/mscc_main.c
+++ b/drivers/net/phy/mscc/mscc_main.c
@@ -1685,6 +1685,25 @@ static int vsc8574_config_host_serdes(struct phy_device *phydev)
 			   PROC_CMD_RST_CONF_PORT | PROC_CMD_FIBER_1000BASE_X);
 }
 
+static int vsc85xx_config_inband_aneg(struct phy_device *phydev, bool enabled)
+{
+	int rc;
+	u16 reg_val = 0;
+
+	if (enabled)
+		reg_val = MSCC_PHY_SERDES_ANEG;
+
+	mutex_lock(&phydev->lock);
+
+	rc = phy_modify_paged(phydev, MSCC_PHY_PAGE_EXTENDED_3,
+			      MSCC_PHY_SERDES_PCS_CTRL, MSCC_PHY_SERDES_ANEG,
+			      reg_val);
+
+	mutex_unlock(&phydev->lock);
+
+	return rc;
+}
+
 static int vsc8584_config_init(struct phy_device *phydev)
 {
 	struct vsc8531_private *vsc8531 = phydev->priv;
@@ -1772,6 +1791,11 @@ static int vsc8584_config_init(struct phy_device *phydev)
 					      VSC8572_RGMII_TX_DELAY_MASK);
 		if (ret)
 			return ret;
+	} else {
+		/* Enable clause 37 */
+		ret = vsc85xx_config_inband_aneg(phydev, true);
+		if (ret)
+			return ret;
 	}
 
 	ret = genphy_soft_reset(phydev);
-- 
2.7.4