[PATCH net-next v9 11/15] net: phy: at803x: Support SFP through phy_port interface

[Maxime Chevallier <maxime.chevallier@bootlin.com>]

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
somwhat compatible with 1000BaseX).

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
---
 drivers/net/phy/qcom/at803x.c | 64 ++++++++++-------------------------
 1 file changed, 17 insertions(+), 47 deletions(-)

diff --git a/drivers/net/phy/qcom/at803x.c b/drivers/net/phy/qcom/at803x.c
index 51a132242462..526c88051487 100644
--- 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"
@@ -769,58 +769,28 @@ 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 at8031_attach_port(struct phy_device *phydev, struct phy_port *port)
 {
-	struct phy_device *phydev = upstream;
-	__ETHTOOL_DECLARE_LINK_MODE_MASK(phy_support);
-	__ETHTOOL_DECLARE_LINK_MODE_MASK(sfp_support);
-	DECLARE_PHY_INTERFACE_MASK(interfaces);
-	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);
-
-	linkmode_zero(sfp_support);
-	sfp_parse_support(phydev->sfp_bus, id, sfp_support, interfaces);
-	/* 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, sfp_support);
-
-	if (linkmode_empty(sfp_support)) {
-		dev_err(&phydev->mdio.dev, "incompatible SFP module inserted\n");
-		return -EINVAL;
-	}
+	if (!port->is_mii)
+		return 0;
 
-	iface = sfp_select_interface(phydev->sfp_bus, sfp_support);
+	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);
 
-	/* 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.
+	/* 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);
 
 	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;
@@ -841,8 +811,7 @@ 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)
@@ -1173,6 +1142,7 @@ 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_port		= at8031_attach_port,
 }, {
 	/* Qualcomm Atheros AR8032 */
 	PHY_ID_MATCH_EXACT(ATH8032_PHY_ID),
-- 
2.49.0