[net-next: PATCH 07/12] net: mdio: allow registering non-PHY devices in ACPI world

[Marcin Wojtas]

This patch utilizes the newly added fwnode_mdiobus_register_device
function and enables registration of non-PHY MDIO devices.
For that purpose a helper routine is added, allowing to determine,
whether the device associated to ACPI node is a PHY.
In addition to that update, allow matching child devices' drivers
based on their ACPI ID.

Signed-off-by: Marcin Wojtas <mw@xxxxxxxxxxxx>
---
 drivers/net/mdio/acpi_mdio.c | 40 +++++++++++++++++++-
 drivers/net/phy/mdio_bus.c   |  4 ++
 2 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/drivers/net/mdio/acpi_mdio.c b/drivers/net/mdio/acpi_mdio.c
index d77c987fda9c..b5d7404afc5e 100644
--- a/drivers/net/mdio/acpi_mdio.c
+++ b/drivers/net/mdio/acpi_mdio.c
@@ -17,6 +17,41 @@
 MODULE_AUTHOR("Calvin Johnson <calvin.johnson@xxxxxxxxxxx>");
 MODULE_LICENSE("GPL");
 
+/**
+ * acpi_mdiobus_child_is_phy - check if device associated with fwnode is a PHY.
+ * @fwnode: pointer to MDIO bus child fwnode and is expected to represent ACPI
+ * device object.
+ *
+ * The function returns true if the child node is for a PHY.
+ * It must comprise either:
+ * o Compatible string of "ethernet-phy-idX.X"
+ * o Compatible string of "ethernet-phy-ieee802.3-c45"
+ * o Compatible string of "ethernet-phy-ieee802.3-c22"
+ * o No _HID or _CID fields.
+ */
+static bool acpi_mdiobus_child_is_phy(struct fwnode_handle *child)
+{
+	struct acpi_device *adev = to_acpi_device_node(child);
+	u32 phy_id;
+
+	if (fwnode_get_phy_id(child, &phy_id) != -EINVAL)
+		return true;
+
+	if (fwnode_property_match_string(child, "compatible",
+					 "ethernet-phy-ieee802.3-c45") == 0)
+		return true;
+
+	if (fwnode_property_match_string(child, "compatible",
+					 "ethernet-phy-ieee802.3-c22") == 0)
+		return true;
+
+	/* Default to PHY if no _HID or _CID found in the fwnode. */
+	if (list_empty(&adev->pnp.ids))
+		return true;
+
+	return false;
+}
+
 /**
  * acpi_mdiobus_register - Register mii_bus and create PHYs from the ACPI ASL.
  * @mdio: pointer to mii_bus structure
@@ -47,7 +82,10 @@ int acpi_mdiobus_register(struct mii_bus *mdio, struct fwnode_handle *fwnode)
 		if (ret || addr >= PHY_MAX_ADDR)
 			continue;
 
-		ret = fwnode_mdiobus_register_phy(mdio, child, addr);
+		if (acpi_mdiobus_child_is_phy(child))
+			ret = fwnode_mdiobus_register_phy(mdio, child, addr);
+		else
+			ret = fwnode_mdiobus_register_device(mdio, child, addr);
 		if (ret == -ENODEV)
 			dev_err(&mdio->dev,
 				"MDIO device at address %d is missing.\n",
diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 8a2dbe849866..b3c2f966be4b 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c
@@ -8,6 +8,7 @@
 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
+#include <linux/acpi.h>
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/errno.h>
@@ -989,6 +990,9 @@ static int mdio_bus_match(struct device *dev, struct device_driver *drv)
 	if (of_driver_match_device(dev, drv))
 		return 1;
 
+	if (acpi_driver_match_device(dev, drv))
+		return 1;
+
 	if (mdio->bus_match)
 		return mdio->bus_match(dev, drv);
 
-- 
2.29.0