[PATCH v2 4/4] net: qcom/emac: add acpi shared mdio bus support

[Wang Dongsheng]

Parsing _DSD package "mdio-device".

Signed-off-by: Wang Dongsheng <dongsheng.w...@hxt-semitech.com>
---
 drivers/net/ethernet/qualcomm/emac/emac-phy.c | 51 +++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/drivers/net/ethernet/qualcomm/emac/emac-phy.c 
b/drivers/net/ethernet/qualcomm/emac/emac-phy.c
index 4f98f9a0ed54..7a96bcf15d3f 100644
--- a/drivers/net/ethernet/qualcomm/emac/emac-phy.c
+++ b/drivers/net/ethernet/qualcomm/emac/emac-phy.c
@@ -97,6 +97,51 @@ 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 int emac_acpi_get_shared_bus(struct platform_device *pdev,
+                                   struct mii_bus **bus)
+{
+       struct fwnode_reference_args args;
+       struct fwnode_handle *fw_node;
+
+       struct device *shared_dev;
+       struct net_device *shared_netdev;
+       struct emac_adapter *shared_adpt;
+       int ret;
+
+       if (!has_acpi_companion(&pdev->dev))
+               return -ENODEV;
+
+       fw_node = acpi_fwnode_handle(ACPI_COMPANION(&pdev->dev));
+       ret = acpi_node_get_property_reference(fw_node, "mdio-device", 0,
+                                              &args);
+       if (ACPI_FAILURE(ret) || !is_acpi_device_node(args.fwnode)) {
+               dev_err(&pdev->dev, "Missing mdio-device property\n");
+               return -ENODEV;
+       }
+
+       shared_dev = bus_find_device(&platform_bus_type, NULL,
+                                    args.fwnode,
+                                    acpi_device_match);
+       if (!shared_dev)
+               return -EPROBE_DEFER;
+
+       shared_netdev = dev_get_drvdata(shared_dev);
+       if (!shared_netdev)
+               return -EPROBE_DEFER;
+
+       shared_adpt = netdev_priv(shared_netdev);
+       if (!shared_adpt->mii_bus)
+               return -EPROBE_DEFER;
+
+       *bus = shared_adpt->mii_bus;
+       return 0;
+}
+
 static int emac_of_get_shared_bus(struct platform_device *pdev,
                                  struct mii_bus **bus)
 {
@@ -137,6 +182,12 @@ static int emac_of_get_shared_bus(struct platform_device 
*pdev,
 static int __do_get_emac_mido_shared_bus(struct platform_device *pdev,
                                         struct emac_adapter *adpt)
 {
+       int ret;
+
+       ret = emac_acpi_get_shared_bus(pdev, &adpt->mii_bus);
+       if (adpt->mii_bus || ret == -EPROBE_DEFER)
+               return ret;
+
        return emac_of_get_shared_bus(pdev, &adpt->mii_bus);
 }
 
-- 
2.18.0