net: phy: at803x: Support SFP through phy_port interface

Convert the at803x driver to use the generic phylib SFP handling, via a
dedicated .attach_port() callback, populating the supported interfaces.

As these devices are limited to 1000BaseX, a workaround is used to also
support, in a very limited way, copper modules. This is done by
supporting SGMII but limiting it to 1G full duplex (in which case it's
somewhat compatible with 1000BaseX).

Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Link: https://patch.msgid.link/20260108080041.553250-12-maxime.chevallier@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/phy/qcom/at803x.c b/drivers/net/phy/qcom/at803x.c
index 338acd11a9b65e9b03f503b207124d1f235c28ff..2995b08bac9632b47c333c11de69a022196ccbff 100644 (file)
--- a/drivers/net/phy/qcom/at803x.c
+++ b/drivers/net/phy/qcom/at803x.c
@@ -20,7 +20,7 @@
 #include <linux/of.h>
 #include <linux/phylink.h>
 #include <linux/reset.h>
-#include <linux/sfp.h>
+#include <linux/phy_port.h>
 #include <dt-bindings/net/qca-ar803x.h>
 
 #include "qcom.h"
@@ -769,57 +769,44 @@ static int at8031_register_regulators(struct phy_device *phydev)
        return 0;
 }
 
-static int at8031_sfp_insert(void *upstream, const struct sfp_eeprom_id *id)
+static int at803x_configure_mii(struct phy_port *port, bool enable,
+                               phy_interface_t interface)
 {
-       __ETHTOOL_DECLARE_LINK_MODE_MASK(phy_support);
-       __ETHTOOL_DECLARE_LINK_MODE_MASK(sfp_support);
-       struct phy_device *phydev = upstream;
-       const struct sfp_module_caps *caps;
-       phy_interface_t iface;
-
-       linkmode_zero(phy_support);
-       phylink_set(phy_support, 1000baseX_Full);
-       phylink_set(phy_support, 1000baseT_Full);
-       phylink_set(phy_support, Autoneg);
-       phylink_set(phy_support, Pause);
-       phylink_set(phy_support, Asym_Pause);
-
-       caps = sfp_get_module_caps(phydev->sfp_bus);
-       /* Some modules support 10G modes as well as others we support.
-        * Mask out non-supported modes so the correct interface is picked.
-        */
-       linkmode_and(sfp_support, phy_support, caps->link_modes);
+       struct phy_device *phydev = port_phydev(port);
 
-       if (linkmode_empty(sfp_support)) {
-               dev_err(&phydev->mdio.dev, "incompatible SFP module inserted\n");
-               return -EINVAL;
-       }
+       if (interface == PHY_INTERFACE_MODE_SGMII)
+               dev_warn(&phydev->mdio.dev,
+                        "module may not function if 1000Base-X not supported\n");
+
+       return 0;
+}
 
-       iface = sfp_select_interface(phydev->sfp_bus, sfp_support);
+static const struct phy_port_ops at803x_port_ops = {
+       .configure_mii = at803x_configure_mii,
+};
 
-       /* Only 1000Base-X is supported by AR8031/8033 as the downstream SerDes
-        * interface for use with SFP modules.
-        * However, some copper modules detected as having a preferred SGMII
-        * interface do default to and function in 1000Base-X mode, so just
-        * print a warning and allow such modules, as they may have some chance
-        * of working.
+static int at8031_attach_mii_port(struct phy_device *phydev,
+                                 struct phy_port *port)
+{
+       linkmode_zero(port->supported);
+       phylink_set(port->supported, 1000baseX_Full);
+       phylink_set(port->supported, 1000baseT_Full);
+       phylink_set(port->supported, Autoneg);
+       phylink_set(port->supported, Pause);
+       phylink_set(port->supported, Asym_Pause);
+
+       /* This device doesn't really support SGMII. However, do our best
+        * to be compatible with copper modules (that usually require SGMII),
+        * in a degraded mode as we only allow 1000BaseT Full
         */
-       if (iface == PHY_INTERFACE_MODE_SGMII)
-               dev_warn(&phydev->mdio.dev, "module may not function if 1000Base-X not supported\n");
-       else if (iface != PHY_INTERFACE_MODE_1000BASEX)
-               return -EINVAL;
+       __set_bit(PHY_INTERFACE_MODE_SGMII, port->interfaces);
+       __set_bit(PHY_INTERFACE_MODE_1000BASEX, port->interfaces);
+
+       port->ops = &at803x_port_ops;
 
        return 0;
 }
 
-static const struct sfp_upstream_ops at8031_sfp_ops = {
-       .attach = phy_sfp_attach,
-       .detach = phy_sfp_detach,
-       .module_insert = at8031_sfp_insert,
-       .connect_phy = phy_sfp_connect_phy,
-       .disconnect_phy = phy_sfp_disconnect_phy,
-};
-
 static int at8031_parse_dt(struct phy_device *phydev)
 {
        struct device_node *node = phydev->mdio.dev.of_node;
@@ -840,8 +827,7 @@ static int at8031_parse_dt(struct phy_device *phydev)
                return ret;
        }
 
-       /* Only AR8031/8033 support 1000Base-X for SFP modules */
-       return phy_sfp_probe(phydev, &at8031_sfp_ops);
+       return 0;
 }
 
 static int at8031_probe(struct phy_device *phydev)
@@ -1172,6 +1158,7 @@ static struct phy_driver at803x_driver[] = {
        .set_tunable            = at803x_set_tunable,
        .cable_test_start       = at8031_cable_test_start,
        .cable_test_get_status  = at8031_cable_test_get_status,
+       .attach_mii_port        = at8031_attach_mii_port,
 }, {
        /* Qualcomm Atheros AR8032 */
        PHY_ID_MATCH_EXACT(ATH8032_PHY_ID),