[PATCH net 1/1] net: phy: marvell: add Marvell specific PHY loopback

[Mohammad Athari Bin Ismail <mohammad.athari.ismail@intel.com>]

Existing genphy_loopback() is not applicable for Marvell PHY. So,
adding Marvell specific PHY loopback operation by only setting(enable) or
clearing(disable) BMCR_LOOPBACK bit.

Tested working on Marvell 88E1510.

Fixes: 014068dcb5b1 ("net: phy: genphy_loopback: add link speed configuration")
Cc: <stable@vger.kernel.org> # 5.15.x
Signed-off-by: Mohammad Athari Bin Ismail <mohammad.athari.ismail@intel.com>
---
 drivers/net/phy/marvell.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/net/phy/marvell.c b/drivers/net/phy/marvell.c
index 4fcfca4e1702..2a73a959b48b 100644
--- a/drivers/net/phy/marvell.c
+++ b/drivers/net/phy/marvell.c
@@ -1932,6 +1932,12 @@ static void marvell_get_stats(struct phy_device *phydev,
 		data[i] = marvell_get_stat(phydev, i);
 }
 
+static int marvell_loopback(struct phy_device *phydev, bool enable)
+{
+	return phy_modify(phydev, MII_BMCR, BMCR_LOOPBACK,
+			  enable ? BMCR_LOOPBACK : 0);
+}
+
 static int marvell_vct5_wait_complete(struct phy_device *phydev)
 {
 	int i;
@@ -3078,7 +3084,7 @@ static struct phy_driver marvell_drivers[] = {
 		.get_sset_count = marvell_get_sset_count,
 		.get_strings = marvell_get_strings,
 		.get_stats = marvell_get_stats,
-		.set_loopback = genphy_loopback,
+		.set_loopback = marvell_loopback,
 		.get_tunable = m88e1011_get_tunable,
 		.set_tunable = m88e1011_set_tunable,
 		.cable_test_start = marvell_vct7_cable_test_start,
-- 
2.17.1