[PATCH v3 2/2] net: qcom/emac: add phy-handle support for ACPI

[Wang Dongsheng <dongsheng.wang@hxt-semitech.com>]

Use "phy-handle" to porint an internal MDIO device port.

Signed-off-by: Wang Dongsheng <dongsheng.wang@hxt-semitech.com>
---
 drivers/net/ethernet/qualcomm/emac/emac-phy.c | 115 +++++++++++++++---
 1 file changed, 100 insertions(+), 15 deletions(-)

diff --git a/drivers/net/ethernet/qualcomm/emac/emac-phy.c b/drivers/net/ethernet/qualcomm/emac/emac-phy.c
index f2ed013ce5d5..3dc3ae55e5bb 100644
--- a/drivers/net/ethernet/qualcomm/emac/emac-phy.c
+++ b/drivers/net/ethernet/qualcomm/emac/emac-phy.c
@@ -96,6 +96,96 @@ static int emac_mdio_write(struct mii_bus *bus, int addr, int regnum, u16 val)
 	return 0;
 }
 
+static int acpi_device_match(struct device *dev, void *fwnode)
+{
+	return dev->fwnode == fwnode;
+}
+
+static struct phy_device *
+emac_acpi_get_phydev_from_phy_handle(struct platform_device *pdev)
+{
+	struct fwnode_reference_args args;
+	struct fwnode_handle *fw_node;
+	struct acpi_device *adev;
+	acpi_handle handle;
+	struct device *dev;
+	struct phy_device *phydev;
+	struct net_device *netdev;
+	struct emac_adapter *adpt;
+	int phy_addr;
+	int ret;
+
+	/* Get PHY Port reference from phy-handle */
+	fw_node = acpi_fwnode_handle(ACPI_COMPANION(&pdev->dev));
+	ret = acpi_node_get_property_reference(fw_node, "phy-handle", 0,
+					       &args);
+	if (ACPI_FAILURE(ret) || !is_acpi_device_node(args.fwnode))
+		return ERR_PTR(-ENODEV);
+
+	/* Get PHY addr from the port node */
+	if (fwnode_property_read_u32(args.fwnode, "phy-channel", &phy_addr))
+		return ERR_PTR(-ENODEV);
+
+	/* Get the MDIO bus that included the port */
+	handle = ACPI_HANDLE_FWNODE(args.fwnode);
+	if (!handle || acpi_bus_get_device(handle, &adev))
+		return ERR_PTR(-ENODEV);
+
+	while (adev->parent) {
+		if (!strcmp(acpi_device_hid(adev), "QCOM8070"))
+			break;
+		adev = adev->parent;
+	}
+	if (!adev->parent)
+		return ERR_PTR(-ENODEV);
+
+	dev = bus_find_device(&platform_bus_type, NULL,
+			      &adev->fwnode,
+			      acpi_device_match);
+	if (!dev)
+		return ERR_PTR(-ENODEV);
+
+	netdev = dev_get_drvdata(dev);
+	if (!netdev)
+		return ERR_PTR(-EPROBE_DEFER);
+
+	adpt = netdev_priv(netdev);
+	if (!adpt->mii_bus)
+		return ERR_PTR(-EPROBE_DEFER);
+
+	phydev = mdiobus_get_phy(adpt->mii_bus, phy_addr);
+	return phydev ? phydev : ERR_PTR(-ENODEV);
+}
+
+static struct phy_device *
+emac_acpi_get_phydev(struct platform_device *pdev, struct emac_adapter *adpt)
+{
+	struct phy_device *phydev = NULL;
+	int phy_addr;
+	int ret;
+
+	/* Compatible with "phy-channel" */
+	ret = device_property_read_u32(&pdev->dev, "phy-channel",
+				       &phy_addr);
+	if (!ret)
+		phydev = mdiobus_get_phy(adpt->mii_bus, phy_addr);
+	if (phydev)
+		return phydev;
+
+	/* Get PHY Port reference from phy-handle */
+	phydev = emac_acpi_get_phydev_from_phy_handle(pdev);
+	if (!IS_ERR(phydev))
+		return phydev;
+	if (PTR_ERR(phydev) == -EPROBE_DEFER)
+		return ERR_PTR(-EPROBE_DEFER);
+
+	/* If we can't read a valid phy address from "phy-channel"/"phy-handle",
+	 * then assume that there is only one phy on local mdio bus.
+	 */
+	phydev = phy_find_first(adpt->mii_bus);
+	return phydev ? phydev : ERR_PTR(-ENODEV);
+}
+
 static int emac_mdio_bus_create(struct platform_device *pdev,
 				struct emac_adapter *adpt)
 {
@@ -128,13 +218,9 @@ static int emac_get_phydev(struct platform_device *pdev,
 			    struct emac_adapter *adpt)
 {
 	struct device_node *np = pdev->dev.of_node;
-	struct mii_bus *bus = adpt->mii_bus;
 	struct device_node *phy_np;
 	struct phy_device *phydev;
 
-	u32 phy_addr;
-	int ret;
-
 	if (!has_acpi_companion(&pdev->dev)) {
 		phy_np = of_parse_phandle(np, "phy-handle", 0);
 		adpt->phydev = of_phy_find_device(phy_np);
@@ -142,14 +228,9 @@ static int emac_get_phydev(struct platform_device *pdev,
 		return adpt->phydev ? 0 : -ENODEV;
 	}
 
-	ret = device_property_read_u32(&pdev->dev, "phy-channel",
-				       &phy_addr);
-	/* If we can't read a valid phy address, then assume
-	 * that there is only one phy on this mdio bus.
-	 */
-	phydev = ret ? phy_find_first(bus) : mdiobus_get_phy(bus, phy_addr);
-	if (!phydev)
-		return -ENODEV;
+	phydev = emac_acpi_get_phydev(pdev, adpt);
+	if (IS_ERR(phydev))
+		return PTR_ERR(phydev);
 
 	/* of_phy_find_device() claims a reference to the phydev,
 	 * so we do that here manually as well. When the driver
@@ -171,10 +252,14 @@ int emac_phy_config(struct platform_device *pdev, struct emac_adapter *adpt)
 		return ret;
 
 	ret = emac_get_phydev(pdev, adpt);
-	if (ret) {
+	if (!ret)
+		return 0;
+
+	if (ret != -EPROBE_DEFER)
 		dev_err(&pdev->dev, "Could not find external phy\n");
-		mdiobus_unregister(adpt->mii_bus);
-	}
+	else
+		dev_warn(&pdev->dev, "Phy is not available yet, deferred probing\n");
 
+	mdiobus_unregister(adpt->mii_bus);
 	return ret;
 }
-- 
2.18.0