net: phy: dp83869: support mii mode when rgmii strap cfg is used

The DP83869 PHY on TI's k3-am642-evm supports both MII and RGMII
interfaces and is configured by default to use RGMII interface (strap).
However, the board design allows switching dynamically to MII interface
for testing purposes by applying different set of pinmuxes.

To support switching to MII interface, update the DP83869 PHY driver to
configure OP_MODE_DECODE.RGMII_MII_SEL(bit 5) properly when MII PHY
interface mode is requested.

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20230508070359.357474-1-s-vadapalli@ti.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/phy/dp83869.c b/drivers/net/phy/dp83869.c
index 9ab5eff502b71640b1022baf1d6b7567a65c240f..fa8c6fdcf30181067c7c3f164e997171908a70b8 100644 (file)
--- a/drivers/net/phy/dp83869.c
+++ b/drivers/net/phy/dp83869.c
@@ -692,8 +692,19 @@ static int dp83869_configure_mode(struct phy_device *phydev,
        /* Below init sequence for each operational mode is defined in
         * section 9.4.8 of the datasheet.
         */
+       phy_ctrl_val = dp83869->mode;
+       if (phydev->interface == PHY_INTERFACE_MODE_MII) {
+               if (dp83869->mode == DP83869_100M_MEDIA_CONVERT ||
+                   dp83869->mode == DP83869_RGMII_100_BASE) {
+                       phy_ctrl_val |= DP83869_OP_MODE_MII;
+               } else {
+                       phydev_err(phydev, "selected op-mode is not valid with MII mode\n");
+                       return -EINVAL;
+               }
+       }
+
        ret = phy_write_mmd(phydev, DP83869_DEVADDR, DP83869_OP_MODE,
-                           dp83869->mode);
+                           phy_ctrl_val);
        if (ret)
                return ret;