[RFC PATCH v2 net-next 5/5] net: phy: mscc: configure in-band auto-negotiation for VSC8514

[Vladimir Oltean <vladimir.oltean@nxp.com>]

Add the in-band configuration knob for the VSC8514 quad PHY. Tested with
QSGMII in-band AN both on and off on NXP LS1028A-RDB and T1040-RDB.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
---
 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 a50235fdf7d9..366db1425561 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 6e32da28e138..ca537204bc27 100644
--- a/drivers/net/phy/mscc/mscc_main.c
+++ b/drivers/net/phy/mscc/mscc_main.c
@@ -2189,6 +2189,24 @@ static int vsc85xx_read_status(struct phy_device *phydev)
 	return genphy_read_status(phydev);
 }
 
+static int vsc8514_validate_inband_aneg(struct phy_device *phydev,
+					phy_interface_t interface)
+{
+	return PHY_INBAND_ANEG_OFF | PHY_INBAND_ANEG_ON;
+}
+
+static int vsc8514_config_inband_aneg(struct phy_device *phydev, bool enabled)
+{
+	int reg_val = 0;
+
+	if (enabled)
+		reg_val = MSCC_PHY_SERDES_ANEG;
+
+	return phy_modify_paged(phydev, MSCC_PHY_PAGE_EXTENDED_3,
+				MSCC_PHY_SERDES_PCS_CTRL, MSCC_PHY_SERDES_ANEG,
+				reg_val);
+}
+
 static int vsc8514_probe(struct phy_device *phydev)
 {
 	struct vsc8531_private *vsc8531;
@@ -2395,6 +2413,8 @@ static struct phy_driver vsc85xx_driver[] = {
 	.get_sset_count = &vsc85xx_get_sset_count,
 	.get_strings    = &vsc85xx_get_strings,
 	.get_stats      = &vsc85xx_get_stats,
+	.validate_inband_aneg = vsc8514_validate_inband_aneg,
+	.config_inband_aneg = vsc8514_config_inband_aneg,
 },
 {
 	.phy_id		= PHY_ID_VSC8530,
-- 
2.25.1