[PATCH v4 6/6] net: phy: qca8084: add qca8084_link_change_notify

[Luo Jie <quic_luoj@quicinc.com>]

When the link is changed, qca8084 needs to do the fifo reset and
adjust the IPG level for the qusgmii link speed 1000M.

Signed-off-by: Luo Jie <quic_luoj@quicinc.com>
---
 drivers/net/phy/at803x.c | 37 +++++++++++++++++++++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/drivers/net/phy/at803x.c b/drivers/net/phy/at803x.c
index 06a068ca5539..7267ce858937 100644
--- a/drivers/net/phy/at803x.c
+++ b/drivers/net/phy/at803x.c
@@ -289,6 +289,13 @@
 #define QCA8084_MSE_THRESHOLD			0x800a
 #define QCA8084_MSE_THRESHOLD_2P5G_VAL		0x51c6
 
+#define QCA8084_FIFO_CONTROL			0x19
+#define QCA8084_FIFO_MAC_2_PHY			BIT(1)
+#define QCA8084_FIFO_PHY_2_MAC			BIT(0)
+
+#define QCA8084_MMD7_IPG_OP			0x901d
+#define QCA8084_IPG_10_TO_11_EN			BIT(0)
+
 MODULE_DESCRIPTION("Qualcomm Atheros AR803x and QCA808X PHY driver");
 MODULE_AUTHOR("Matus Ujhelyi");
 MODULE_LICENSE("GPL");
@@ -2109,6 +2116,35 @@ static int qca8084_config_init(struct phy_device *phydev)
 			     QCA8084_MSE_THRESHOLD, QCA8084_MSE_THRESHOLD_2P5G_VAL);
 }
 
+static void qca8084_link_change_notify(struct phy_device *phydev)
+{
+	int ret;
+
+	ret = phy_modify(phydev, QCA8084_FIFO_CONTROL,
+			 QCA8084_FIFO_MAC_2_PHY | QCA8084_FIFO_PHY_2_MAC,
+			 0);
+	if (ret)
+		return;
+
+	/* If the PHY works on PHY_INTERFACE_MODE_10G_QXGMII mode, the fifo needs to
+	 * be kept as reset state in link down status.
+	 */
+	if (phydev->interface != PHY_INTERFACE_MODE_10G_QXGMII || phydev->link) {
+		msleep(50);
+		ret = phy_modify(phydev, QCA8084_FIFO_CONTROL,
+				 QCA8084_FIFO_MAC_2_PHY | QCA8084_FIFO_PHY_2_MAC,
+				 QCA8084_FIFO_MAC_2_PHY | QCA8084_FIFO_PHY_2_MAC);
+		if (ret)
+			return;
+	}
+
+	/* Enable IPG 10 to 11 tuning on link speed 1000M of QUSGMII mode. */
+	if (phydev->interface == PHY_INTERFACE_MODE_10G_QXGMII)
+		phy_modify_mmd(phydev, MDIO_MMD_AN, QCA8084_MMD7_IPG_OP,
+			       QCA8084_IPG_10_TO_11_EN,
+			       phydev->speed == SPEED_1000 ? QCA8084_IPG_10_TO_11_EN : 0);
+}
+
 static struct phy_driver at803x_driver[] = {
 {
 	/* Qualcomm Atheros AR8035 */
@@ -2307,6 +2343,7 @@ static struct phy_driver at803x_driver[] = {
 	.cable_test_start	= qca808x_cable_test_start,
 	.cable_test_get_status	= qca808x_cable_test_get_status,
 	.config_init		= qca8084_config_init,
+	.link_change_notify	= qca8084_link_change_notify,
 }, };
 
 module_phy_driver(at803x_driver);
-- 
2.42.0