Associate with an SFP cage described in the device tree and provide the
module_insert() callback that will set the appropriate DP83869 operation
mode when an SFP module is inserted.

Signed-off-by: Romain Gantois <romain.gantois@bootlin.com>
---
 drivers/net/phy/dp83869.c | 78 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 78 insertions(+)

diff --git a/drivers/net/phy/dp83869.c b/drivers/net/phy/dp83869.c
index adcd899472f2..e279dfa268a4 100644
--- a/drivers/net/phy/dp83869.c
+++ b/drivers/net/phy/dp83869.c
@@ -10,6 +10,7 @@
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/phy.h>
+#include <linux/sfp.h>
 #include <linux/delay.h>
 #include <linux/bitfield.h>
 
@@ -875,6 +876,77 @@ static int dp83869_config_init(struct phy_device *phydev)
 	return ret;
 }
 
+static void dp83869_module_remove(void *upstream)
+{
+	struct phy_device *phydev = upstream;
+
+	phydev_info(phydev, "SFP module removed\n");
+
+	/* Set speed and duplex to unknown to avoid downshifting warning. */
+	phydev->speed = SPEED_UNKNOWN;
+	phydev->duplex = DUPLEX_UNKNOWN;
+}
+
+static int dp83869_module_insert(void *upstream, const struct sfp_eeprom_id *id)
+{
+	__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;
+	struct dp83869_private *dp83869;
+	phy_interface_t interface;
+	int ret;
+
+	linkmode_zero(phy_support);
+	linkmode_set_bit(ETHTOOL_LINK_MODE_1000baseX_Full_BIT, phy_support);
+
+	caps = sfp_get_module_caps(phydev->sfp_bus);
+
+	linkmode_and(sfp_support, phy_support, caps->link_modes);
+
+	if (linkmode_empty(sfp_support)) {
+		phydev_err(phydev, "incompatible SFP module inserted\n");
+		return -EINVAL;
+	}
+
+	interface = sfp_select_interface(phydev->sfp_bus, sfp_support);
+
+	phydev_info(phydev, "%s SFP compatible link mode: %s\n", __func__,
+		    phy_modes(interface));
+
+	dp83869 = phydev->priv;
+
+	switch (interface) {
+	case PHY_INTERFACE_MODE_1000BASEX:
+		dp83869->mode = DP83869_RGMII_1000_BASE;
+		phydev->port = PORT_FIBRE;
+		break;
+	default:
+		phydev_err(phydev, "incompatible PHY-to-SFP module link mode %s!\n",
+			   phy_modes(interface));
+		return -EINVAL;
+	}
+
+	ret = dp83869_configure_mode(phydev, dp83869);
+	if (ret)
+		return ret;
+
+	/* Reconfigure advertisement */
+	if (mutex_trylock(&phydev->lock)) {
+		ret = dp83869_config_aneg(phydev);
+		mutex_unlock(&phydev->lock);
+	}
+
+	return ret;
+}
+
+static const struct sfp_upstream_ops dp83869_sfp_ops = {
+	.attach = phy_sfp_attach,
+	.detach = phy_sfp_detach,
+	.module_insert = dp83869_module_insert,
+	.module_remove = dp83869_module_remove,
+};
+
 static int dp83869_probe(struct phy_device *phydev)
 {
 	struct dp83869_private *dp83869;
@@ -891,6 +963,12 @@ static int dp83869_probe(struct phy_device *phydev)
 	if (ret)
 		return ret;
 
+	if (of_property_read_bool(phydev->mdio.dev.of_node, "sfp")) {
+		ret = phy_sfp_probe(phydev, &dp83869_sfp_ops);
+		if (ret)
+			return ret;
+	}
+
 	if (dp83869->mode == DP83869_RGMII_100_BASE ||
 	    dp83869->mode == DP83869_RGMII_1000_BASE)
 		phydev->port = PORT_FIBRE;

-- 
2.51.2