[PATCH 14/16] net: phy: adin: make sure down-speed auto-neg is enabled

[Alexandru Ardelean]

Down-speed auto-negotiation may not always be enabled, in which case the
PHY won't down-shift to 100 or 10 during auto-negotiation.

Signed-off-by: Alexandru Ardelean <alexandru.ardel...@analog.com>
---
 drivers/net/phy/adin.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/drivers/net/phy/adin.c b/drivers/net/phy/adin.c
index 86848444bd98..a1f3456a8504 100644
--- a/drivers/net/phy/adin.c
+++ b/drivers/net/phy/adin.c
@@ -32,6 +32,13 @@
 #define   ADIN1300_NRG_PD_TX_EN                        BIT(2)
 #define   ADIN1300_NRG_PD_STATUS               BIT(1)
 
+#define ADIN1300_PHY_CTRL2                     0x0016
+#define   ADIN1300_DOWNSPEED_AN_100_EN         BIT(11)
+#define   ADIN1300_DOWNSPEED_AN_10_EN          BIT(10)
+#define   ADIN1300_GROUP_MDIO_EN               BIT(6)
+#define   ADIN1300_DOWNSPEEDS_EN       \
+       (ADIN1300_DOWNSPEED_AN_100_EN | ADIN1300_DOWNSPEED_AN_10_EN)
+
 #define ADIN1300_INT_MASK_REG                  0x0018
 #define   ADIN1300_INT_MDIO_SYNC_EN            BIT(9)
 #define   ADIN1300_INT_ANEG_STAT_CHNG_EN       BIT(8)
@@ -425,6 +432,22 @@ static int adin_config_mdix(struct phy_device *phydev)
        return phy_write(phydev, ADIN1300_PHY_CTRL1, reg);
 }
 
+static int adin_config_downspeeds(struct phy_device *phydev)
+{
+       int reg;
+
+       reg = phy_read(phydev, ADIN1300_PHY_CTRL2);
+       if (reg < 0)
+               return reg;
+
+       if ((reg & ADIN1300_DOWNSPEEDS_EN) == ADIN1300_DOWNSPEEDS_EN)
+               return 0;
+
+       reg |= ADIN1300_DOWNSPEEDS_EN;
+
+       return phy_write(phydev, ADIN1300_PHY_CTRL2, reg);
+}
+
 static int adin_config_aneg(struct phy_device *phydev)
 {
        int ret;
@@ -433,6 +456,10 @@ static int adin_config_aneg(struct phy_device *phydev)
        if (ret)
                return ret;
 
+       ret = adin_config_downspeeds(phydev);
+       if (ret < 0)
+               return ret;
+
        return genphy_config_aneg(phydev);
 }
 
-- 
2.20.1