[net-next PATCH v6 4/6] net: phy: introduce genphy_match_phy_device()

Christian Marangi
2025-04-07T20:10:10Z

Introduce new API, genphy_match_phy_device(), to provide a way to check
to match a PHY driver for a PHY device based on the info stored in the
PHY device struct.

The function generalize the logic used in phy_bus_match() to check the
PHY ID whether if C45 or C22 ID should be used for matching.

This is useful for custom .match_phy_device function that wants to use
the generic logic under some condition. (example a PHY is already setup
and provide the correct PHY ID)

Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
---
drivers/net/phy/phy_device.c | 52 +++++++++++++++++++++++++-----------
include/linux/phy.h | 3 +++
2 files changed, 40 insertions(+), 15 deletions(-)

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 2d6ceacb2986..ead9a047043a 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -503,20 +503,26 @@ static int phy_scan_fixups(struct phy_device *phydev)
return 0;
}

-static int phy_bus_match(struct device *dev, const struct device_driver *drv)
+/**
+ * genphy_match_phy_device - match a PHY device with a PHY driver
+ * @phydev: target phy_device struct
+ * @phydrv: target phy_driver struct
+ *
+ * Description: Checks whether the given PHY device matches the specified
+ * PHY driver. For Clause 45 PHYs, iterates over the available device
+ * identifiers and compares them against the driver's expected PHY ID,
+ * applying the provided mask. For Clause 22 PHYs, a direct ID comparison
+ * is performed.
+ *
+ * Return: 1 if the PHY device matches the driver, 0 otherwise.
+ */
+int genphy_match_phy_device(struct phy_device *phydev,
+ const struct phy_driver *phydrv)
{
- struct phy_device *phydev = to_phy_device(dev);
- const struct phy_driver *phydrv = to_phy_driver(drv);
- const int num_ids = ARRAY_SIZE(phydev->c45_ids.device_ids);
- int i;
-
- if (!(phydrv->mdiodrv.flags & MDIO_DEVICE_IS_PHY))
- return 0;
-
- if (phydrv->match_phy_device)
- return phydrv->match_phy_device(phydev, phydrv);
-
if (phydev->is_c45) {
+ const int num_ids = ARRAY_SIZE(phydev->c45_ids.device_ids);
+ int i;
+
for (i = 1; i < num_ids; i++) {
if (phydev->c45_ids.device_ids[i] == 0xffffffff)
continue;
@@ -525,11 +531,27 @@ static int phy_bus_match(struct device *dev, const struct device_driver *drv)
phydrv->phy_id, phydrv->phy_id_mask))
return 1;
}
+
return 0;
- } else {
- return phy_id_compare(phydev->phy_id, phydrv->phy_id,
- phydrv->phy_id_mask);
}
+
+ return phy_id_compare(phydev->phy_id, phydrv->phy_id,
+ phydrv->phy_id_mask);
+}
+EXPORT_SYMBOL_GPL(genphy_match_phy_device);
+
+static int phy_bus_match(struct device *dev, const struct device_driver *drv)
+{
+ struct phy_device *phydev = to_phy_device(dev);
+ const struct phy_driver *phydrv = to_phy_driver(drv);
+
+ if (!(phydrv->mdiodrv.flags & MDIO_DEVICE_IS_PHY))
+ return 0;
+
+ if (phydrv->match_phy_device)
+ return phydrv->match_phy_device(phydev, phydrv);
+
+ return genphy_match_phy_device(phydev, phydrv);
}

static ssize_t
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 7042ceaadcc6..b7aa805e0ad6 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -1911,6 +1911,9 @@ char *phy_attached_info_irq(struct phy_device *phydev)
__malloc;
void phy_attached_info(struct phy_device *phydev);

+int genphy_match_phy_device(struct phy_device *phydev,
+ const struct phy_driver *phydrv);
+
/* Clause 22 PHY */
int genphy_read_abilities(struct phy_device *phydev);
int genphy_setup_forced(struct phy_device *phydev);
--
2.48.1