[PATCH net-next v14 03/13] net: phy: add helpers to handle sfp phy connect/disconnect

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

There are a few PHY drivers that can handle SFP modules through their
sfp_upstream_ops. Introduce Phylib helpers to keep track of connected
SFP PHYs in a netdevice's namespace, by adding the SFP PHY to the
upstream PHY's netdev's namespace.

By doing so, these SFP PHYs can be enumerated and exposed to users,
which will be able to use their capabilities.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
---
 drivers/net/phy/marvell-88x2222.c |  2 ++
 drivers/net/phy/marvell.c         |  2 ++
 drivers/net/phy/marvell10g.c      |  2 ++
 drivers/net/phy/phy_device.c      | 42 +++++++++++++++++++++++++++++++
 drivers/net/phy/qcom/at803x.c     |  2 ++
 drivers/net/phy/qcom/qca807x.c    |  2 ++
 include/linux/phy.h               |  2 ++
 7 files changed, 54 insertions(+)

diff --git a/drivers/net/phy/marvell-88x2222.c b/drivers/net/phy/marvell-88x2222.c
index b88398e6872b..0b777cdd7078 100644
--- a/drivers/net/phy/marvell-88x2222.c
+++ b/drivers/net/phy/marvell-88x2222.c
@@ -553,6 +553,8 @@ static const struct sfp_upstream_ops sfp_phy_ops = {
 	.link_down = mv2222_sfp_link_down,
 	.attach = phy_sfp_attach,
 	.detach = phy_sfp_detach,
+	.connect_phy = phy_sfp_connect_phy,
+	.disconnect_phy = phy_sfp_disconnect_phy,
 };
 
 static int mv2222_probe(struct phy_device *phydev)
diff --git a/drivers/net/phy/marvell.c b/drivers/net/phy/marvell.c
index b89fbffa6a93..9964bf3dea2f 100644
--- a/drivers/net/phy/marvell.c
+++ b/drivers/net/phy/marvell.c
@@ -3613,6 +3613,8 @@ static const struct sfp_upstream_ops m88e1510_sfp_ops = {
 	.module_remove = m88e1510_sfp_remove,
 	.attach = phy_sfp_attach,
 	.detach = phy_sfp_detach,
+	.connect_phy = phy_sfp_connect_phy,
+	.disconnect_phy = phy_sfp_disconnect_phy,
 };
 
 static int m88e1510_probe(struct phy_device *phydev)
diff --git a/drivers/net/phy/marvell10g.c b/drivers/net/phy/marvell10g.c
index ad43e280930c..6642eb642d4b 100644
--- a/drivers/net/phy/marvell10g.c
+++ b/drivers/net/phy/marvell10g.c
@@ -503,6 +503,8 @@ static int mv3310_sfp_insert(void *upstream, const struct sfp_eeprom_id *id)
 static const struct sfp_upstream_ops mv3310_sfp_ops = {
 	.attach = phy_sfp_attach,
 	.detach = phy_sfp_detach,
+	.connect_phy = phy_sfp_connect_phy,
+	.disconnect_phy = phy_sfp_disconnect_phy,
 	.module_insert = mv3310_sfp_insert,
 };
 
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 1694aae3391f..f613b47f4109 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -1370,6 +1370,48 @@ phy_standalone_show(struct device *dev, struct device_attribute *attr,
 }
 static DEVICE_ATTR_RO(phy_standalone);
 
+/**
+ * phy_sfp_connect_phy - Connect the SFP module's PHY to the upstream PHY
+ * @upstream: pointer to the upstream phy device
+ * @phy: pointer to the SFP module's phy device
+ *
+ * This helper allows keeping track of PHY devices on the link. It adds the
+ * SFP module's phy to the phy namespace of the upstream phy
+ *
+ * Return: 0 on success, otherwise a negative error code.
+ */
+int phy_sfp_connect_phy(void *upstream, struct phy_device *phy)
+{
+	struct phy_device *phydev = upstream;
+	struct net_device *dev = phydev->attached_dev;
+
+	if (dev)
+		return phy_link_topo_add_phy(dev, phy, PHY_UPSTREAM_PHY, phydev);
+
+	return 0;
+}
+EXPORT_SYMBOL(phy_sfp_connect_phy);
+
+/**
+ * phy_sfp_disconnect_phy - Disconnect the SFP module's PHY from the upstream PHY
+ * @upstream: pointer to the upstream phy device
+ * @phy: pointer to the SFP module's phy device
+ *
+ * This helper allows keeping track of PHY devices on the link. It removes the
+ * SFP module's phy to the phy namespace of the upstream phy. As the module phy
+ * will be destroyed, re-inserting the same module will add a new phy with a
+ * new index.
+ */
+void phy_sfp_disconnect_phy(void *upstream, struct phy_device *phy)
+{
+	struct phy_device *phydev = upstream;
+	struct net_device *dev = phydev->attached_dev;
+
+	if (dev)
+		phy_link_topo_del_phy(dev, phy);
+}
+EXPORT_SYMBOL(phy_sfp_disconnect_phy);
+
 /**
  * phy_sfp_attach - attach the SFP bus to the PHY upstream network device
  * @upstream: pointer to the phy device
diff --git a/drivers/net/phy/qcom/at803x.c b/drivers/net/phy/qcom/at803x.c
index c8f83e5f78ab..105602581a03 100644
--- a/drivers/net/phy/qcom/at803x.c
+++ b/drivers/net/phy/qcom/at803x.c
@@ -770,6 +770,8 @@ 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)
diff --git a/drivers/net/phy/qcom/qca807x.c b/drivers/net/phy/qcom/qca807x.c
index 672c6929119a..5eb0ab1cb70e 100644
--- a/drivers/net/phy/qcom/qca807x.c
+++ b/drivers/net/phy/qcom/qca807x.c
@@ -699,6 +699,8 @@ static const struct sfp_upstream_ops qca807x_sfp_ops = {
 	.detach = phy_sfp_detach,
 	.module_insert = qca807x_sfp_insert,
 	.module_remove = qca807x_sfp_remove,
+	.connect_phy = phy_sfp_connect_phy,
+	.disconnect_phy = phy_sfp_disconnect_phy,
 };
 
 static int qca807x_probe(struct phy_device *phydev)
diff --git a/include/linux/phy.h b/include/linux/phy.h
index f6a11aa10691..5308c7512b68 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -1762,6 +1762,8 @@ int phy_suspend(struct phy_device *phydev);
 int phy_resume(struct phy_device *phydev);
 int __phy_resume(struct phy_device *phydev);
 int phy_loopback(struct phy_device *phydev, bool enable);
+int phy_sfp_connect_phy(void *upstream, struct phy_device *phy);
+void phy_sfp_disconnect_phy(void *upstream, struct phy_device *phy);
 void phy_sfp_attach(void *upstream, struct sfp_bus *bus);
 void phy_sfp_detach(void *upstream, struct sfp_bus *bus);
 int phy_sfp_probe(struct phy_device *phydev,
-- 
2.45.1