[PATCH net-next 1/1] net: phy: marvell10g: Add PHY loopback support for 88E2110 PHY

[Wong Vee Khee]

From: Tan Tee Min <tee.min....@intel.com>

Add support for PHY loopback for the Marvell 88E2110 PHY.

This allow user to perform selftest using ethtool.

Signed-off-by: Tan Tee Min <tee.min....@intel.com>
Signed-off-by: Wong Vee Khee <vee.khee.w...@linux.intel.com>
---
 drivers/net/phy/marvell10g.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/net/phy/marvell10g.c b/drivers/net/phy/marvell10g.c
index b1bb9b8e1e4e..c45a8f11bdcf 100644
--- a/drivers/net/phy/marvell10g.c
+++ b/drivers/net/phy/marvell10g.c
@@ -89,6 +89,8 @@ enum {
        MV_V2_TEMP_CTRL_DISABLE = 0xc000,
        MV_V2_TEMP              = 0xf08c,
        MV_V2_TEMP_UNKNOWN      = 0x9600, /* unknown function */
+
+       MV_LOOPBACK             = BIT(14), /* Loopback (88E2110 only) */
 };
 
 struct mv3310_priv {
@@ -765,6 +767,15 @@ static int mv3310_set_tunable(struct phy_device *phydev,
        }
 }
 
+static int mv3310_loopback(struct phy_device *phydev, bool enable)
+{
+       if (phydev->drv->phy_id != MARVELL_PHY_ID_88E2110)
+               return -EOPNOTSUPP;
+
+       return phy_modify_mmd(phydev, MDIO_MMD_PCS, MV_PCS_BASE_T,
+                             MV_LOOPBACK, enable ? MV_LOOPBACK : 0);
+}
+
 static struct phy_driver mv3310_drivers[] = {
        {
                .phy_id         = MARVELL_PHY_ID_88X3310,
@@ -796,6 +807,7 @@ static struct phy_driver mv3310_drivers[] = {
                .get_tunable    = mv3310_get_tunable,
                .set_tunable    = mv3310_set_tunable,
                .remove         = mv3310_remove,
+               .set_loopback   = mv3310_loopback,
        },
 };
 
-- 
2.25.1