[PATCH] net: phy: mscc: Add auto-negotiation feature to VSC8514

[Chintan Vankar <c-vankar@ti.com>]

Add function vsc85xx_config_inband_aneg() in mscc_main.c to enable
auto-negotiation. The function enables auto-negotiation by configuring
the MAC SerDes PCS Control register of VSC8514.

Invoke the vsc85xx_config_inband_aneg() function from the
vsc8514_config_init() function present in mscc_main.c to start the
auto-negotiation process. This is required to get Ethernet working with
the Quad port Ethernet Add-On card connected to J7 common processor board.

Signed-off-by: Chintan Vankar <c-vankar@ti.com>
---

This patch is based on commit '7b7a883c7f4d' of linux-next branch of
Mainline Linux.

Regards,
Chintan.

 drivers/net/phy/mscc/mscc.h      |  2 ++
 drivers/net/phy/mscc/mscc_main.c | 20 ++++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/drivers/net/phy/mscc/mscc.h b/drivers/net/phy/mscc/mscc.h
index 6a3d8a754eb8..3baa0a418bae 100644
--- a/drivers/net/phy/mscc/mscc.h
+++ b/drivers/net/phy/mscc/mscc.h
@@ -196,6 +196,8 @@ 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 19cf12ee8990..f1f36ee1cc59 100644
--- a/drivers/net/phy/mscc/mscc_main.c
+++ b/drivers/net/phy/mscc/mscc_main.c
@@ -1699,6 +1699,21 @@ 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)
+{
+	u16 reg_val = 0;
+	int rc;
+
+	if (enabled)
+		reg_val = MSCC_PHY_SERDES_ANEG;
+
+	rc = phy_modify_paged(phydev, MSCC_PHY_PAGE_EXTENDED_3,
+			      MSCC_PHY_SERDES_PCS_CTRL, MSCC_PHY_SERDES_ANEG,
+			      reg_val);
+
+	return rc;
+}
+
 static int vsc8584_config_init(struct phy_device *phydev)
 {
 	struct vsc8531_private *vsc8531 = phydev->priv;
@@ -2107,6 +2122,11 @@ static int vsc8514_config_init(struct phy_device *phydev)
 
 	ret = genphy_soft_reset(phydev);
 
+	if (ret)
+		return ret;
+
+	ret = vsc85xx_config_inband_aneg(phydev, true);
+
 	if (ret)
 		return ret;
 
-- 
2.34.1