[PATCH net-next v2 3/9] net: phy: ncn26000: Added PHY loopback and read/write MMD callbacks

[Selvamani Rajagopal]

- PHY loopback has to set only BMCR_LOOPBACK bit. As a result, we can't
  use generic, genphy_loopback.
- Direct MMD calls via Clause 45 read/write avoids indirect calls.

Signed-off-by: Selvamani Rajagopal <Selvamani.Rajagopal@xxxxxxxxxx>
---
 drivers/net/phy/ncn26000.c | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/drivers/net/phy/ncn26000.c b/drivers/net/phy/ncn26000.c
index 68b0e4647..d302e04c8 100644
--- a/drivers/net/phy/ncn26000.c
+++ b/drivers/net/phy/ncn26000.c
@@ -162,6 +162,39 @@ static int ncn26000_config_intr(struct phy_device *phydev)
 	return 0;
 }
 
+/* Directly accessing via Clause 45 read avoids the extra
+ * SPI accesses required by indirect access.
+ */
+static int ncn26000_read_mmd(struct phy_device *phydev, int dev, u16 reg)
+{
+	struct mii_bus *bus = phydev->mdio.bus;
+	int addr = phydev->mdio.addr;
+
+	return __mdiobus_c45_read(bus, addr, dev, reg);
+}
+
+/* Directly accessing via Clause 45 write avoids the extra
+ * SPI accesses required by indirect access.
+ */
+static int ncn26000_write_mmd(struct phy_device *phydev, int dev,
+			      u16 reg, u16 val)
+{
+	struct mii_bus *bus = phydev->mdio.bus;
+	int addr = phydev->mdio.addr;
+
+	return __mdiobus_c45_write(bus, addr, dev, reg, val);
+}
+
+static int ncn26000_loopback(struct phy_device *phydev, bool enable, int speed)
+{
+	u16 mask = BMCR_LOOPBACK;
+	u16 ctl = 0;
+
+	if (enable)
+		ctl = BMCR_LOOPBACK;
+	return phy_modify(phydev, MII_BMCR, mask, ctl);
+}
+
 static struct phy_driver ncn26000_driver[] = {
 	{
 		PHY_ID_MATCH_MODEL(PHY_ID_NCN26000),
@@ -176,6 +209,9 @@ static struct phy_driver ncn26000_driver[] = {
 		.set_plca_cfg          = ncn26000_plca_set_cfg,
 		.get_plca_status       = genphy_c45_plca_get_status,
 		.soft_reset            = genphy_soft_reset,
+		.set_loopback          = ncn26000_loopback,
+		.read_mmd              = ncn26000_read_mmd,
+		.write_mmd             = ncn26000_write_mmd,
 	},
 };
 
-- 
2.43.0