net: phy: dp83867: add MDI-X management

ethtool on this phy device always reports "MDI-X: Unknown" and doesn't
support forcing it to on or off.
This patch adds support for reading/forcing MDI-X mode from ethtool
properly.

Signed-off-by: Luca Ellero <l.ellero@asem.it>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20260506141918.13136-1-l.ellero@asem.it
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/phy/dp83867.c b/drivers/net/phy/dp83867.c
index 3fb2293f568f02e8fadb485978fa2a3e2018140e..88255e92b4cdbd6da2e2c1d10f9c72348d28dbc3 100644 (file)
--- a/drivers/net/phy/dp83867.c
+++ b/drivers/net/phy/dp83867.c
@@ -103,6 +103,10 @@
 #define DP83867_PHYCR_RX_FIFO_DEPTH_MASK       GENMASK(13, 12)
 #define DP83867_PHYCR_SGMII_EN                 BIT(11)
 #define DP83867_PHYCR_FORCE_LINK_GOOD          BIT(10)
+#define DP83867_PHYCR_MDIX_MASK                        GENMASK(6, 5)
+#define DP83867_PHYCR_MDIX_MDI                 (0x0 << 5)
+#define DP83867_PHYCR_MDIX_MDIX                        (0x1 << 5)
+#define DP83867_PHYCR_MDIX_AUTO                        (0x3 << 5)
 
 /* RGMIIDCTL bits */
 #define DP83867_RGMII_TX_CLK_DELAY_MAX         0xf
@@ -123,6 +127,10 @@
 #define DP83867_PHYSTS_100                     BIT(14)
 #define DP83867_PHYSTS_DUPLEX                  BIT(13)
 #define DP83867_PHYSTS_LINK                    BIT(10)
+#define DP83867_PHYSTS_MDIX_CD                 BIT(9)
+#define DP83867_PHYSTS_MDIX_AB                 BIT(8)
+#define DP83867_PHYSTS_MDIX_MASK               (DP83867_PHYSTS_MDIX_AB | \
+                                               DP83867_PHYSTS_MDIX_CD)
 
 /* CFG2 bits */
 #define DP83867_DOWNSHIFT_EN           (BIT(8) | BIT(9))
@@ -391,6 +399,22 @@ static int dp83867_read_status(struct phy_device *phydev)
        else
                phydev->speed = SPEED_10;
 
+       if (!(status & DP83867_PHYSTS_LINK)) {
+               phydev->mdix = ETH_TP_MDI_INVALID;
+       } else {
+               switch (status & DP83867_PHYSTS_MDIX_MASK) {
+               case 0:
+                       phydev->mdix = ETH_TP_MDI;
+                       break;
+               case DP83867_PHYSTS_MDIX_MASK:
+                       phydev->mdix = ETH_TP_MDI_X;
+                       break;
+               default:
+                       phydev->mdix = ETH_TP_MDI_INVALID;
+                       break;
+               }
+       }
+
        return 0;
 }
 
@@ -714,6 +738,8 @@ static int dp83867_config_init(struct phy_device *phydev)
        struct dp83867_private *dp83867 = phydev->priv;
        int ret, val, bs;
 
+       phydev->mdix_ctrl = ETH_TP_MDI_AUTO;
+
        /* Force speed optimization for the PHY even if it strapped */
        ret = phy_modify(phydev, DP83867_CFG2, DP83867_DOWNSHIFT_EN,
                         DP83867_DOWNSHIFT_EN);
@@ -873,6 +899,39 @@ static int dp83867_config_init(struct phy_device *phydev)
        return 0;
 }
 
+static int dp83867_config_mdix(struct phy_device *phydev, u8 ctrl)
+{
+       int val;
+
+       switch (ctrl) {
+       case ETH_TP_MDI:
+               val = DP83867_PHYCR_MDIX_MDI;
+               break;
+       case ETH_TP_MDI_X:
+               val = DP83867_PHYCR_MDIX_MDIX;
+               break;
+       case ETH_TP_MDI_AUTO:
+               val = DP83867_PHYCR_MDIX_AUTO;
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       return phy_modify(phydev, MII_DP83867_PHYCTRL,
+                         DP83867_PHYCR_MDIX_MASK, val);
+}
+
+static int dp83867_config_aneg(struct phy_device *phydev)
+{
+       int ret;
+
+       ret = dp83867_config_mdix(phydev, phydev->mdix_ctrl);
+       if (ret)
+               return ret;
+
+       return genphy_config_aneg(phydev);
+}
+
 static int dp83867_phy_reset(struct phy_device *phydev)
 {
        int err;
@@ -1127,6 +1186,7 @@ static struct phy_driver dp83867_driver[] = {
 
                .probe          = dp83867_probe,
                .config_init    = dp83867_config_init,
+               .config_aneg    = dp83867_config_aneg,
                .soft_reset     = dp83867_phy_reset,
 
                .read_status    = dp83867_read_status,