[net-next PATCH v1 7/7] net/fsl: Use _ADR ACPI object to register PHYs

[Calvin Johnson <calvin.johnson@oss.nxp.com>]

PHYs on an mdio bus has address which can be obtained from ACPI
DSDT table using the _ADR object.

DSDT Eg: PHYs connected to MDI0 bus.
-------------------------
Scope(\_SB.MDI0)
{
  Device(PHY1) {
    Name (_ADR, 0x1)
  } // end of PHY1

  Device(PHY2) {
    Name (_ADR, 0x2)
  } // end of PHY2
} // end of MDI0
-------------------------

Signed-off-by: Calvin Johnson <calvin.johnson@oss.nxp.com>
---

 drivers/net/ethernet/freescale/xgmac_mdio.c | 48 +++++++++++++++++++--
 1 file changed, 44 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/freescale/xgmac_mdio.c b/drivers/net/ethernet/freescale/xgmac_mdio.c
index 98be51d8b08c..fb272564855e 100644
--- a/drivers/net/ethernet/freescale/xgmac_mdio.c
+++ b/drivers/net/ethernet/freescale/xgmac_mdio.c
@@ -2,6 +2,7 @@
  * QorIQ 10G MDIO Controller
  *
  * Copyright 2012 Freescale Semiconductor, Inc.
+ * Copyright 2020 NXP
  *
  * Authors: Andy Fleming <afleming@freescale.com>
  *          Timur Tabi <timur@freescale.com>
@@ -11,6 +12,7 @@
  * kind, whether express or implied.
  */
 
+#include <linux/acpi.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/interrupt.h>
@@ -248,6 +250,10 @@ static int xgmac_mdio_probe(struct platform_device *pdev)
 	struct resource *res;
 	struct mdio_fsl_priv *priv;
 	int ret;
+	struct fwnode_handle *fwnode;
+	struct fwnode_handle *child;
+	unsigned long long addr;
+	acpi_status status;
 
 	/* In DPAA-1, MDIO is one of the many FMan sub-devices. The FMan
 	 * defines a register space that spans a large area, covering all the
@@ -284,10 +290,44 @@ static int xgmac_mdio_probe(struct platform_device *pdev)
 
 	priv->has_a011043 = device_property_read_bool(&pdev->dev,
 						      "fsl,erratum-a011043");
-
-	ret = of_mdiobus_register(bus, np);
-	if (ret) {
-		dev_err(&pdev->dev, "cannot register MDIO bus\n");
+	if (is_of_node(pdev->dev.fwnode)) {
+		ret = of_mdiobus_register(bus, np);
+		if (ret) {
+			dev_err(&pdev->dev, "cannot register MDIO bus\n");
+			goto err_registration;
+		}
+	} else if (is_acpi_node(pdev->dev.fwnode)) {
+		priv->is_little_endian = true;
+		/* Mask out all PHYs from auto probing. */
+		bus->phy_mask = ~0;
+		ret = mdiobus_register(bus);
+		if (ret) {
+			dev_err(&pdev->dev, "mdiobus register err(%d)\n", ret);
+			return ret;
+		}
+
+		fwnode = pdev->dev.fwnode;
+	/* Loop over the child nodes and register a phy_device for each PHY */
+		fwnode_for_each_child_node(fwnode, child) {
+			status = acpi_evaluate_integer(ACPI_HANDLE_FWNODE(child),
+						       "_ADR", NULL, &addr);
+			if (ACPI_FAILURE(status)) {
+				pr_debug("_ADR returned %d\n", status);
+				continue;
+			}
+
+			if (addr < 0 || addr >= PHY_MAX_ADDR)
+				continue;
+
+			ret = fwnode_mdiobus_register_phy(bus, child, addr);
+			if (ret == -ENODEV)
+				dev_err(&bus->dev,
+					"MDIO device at address %lld is missing.\n",
+					addr);
+		}
+	} else {
+		dev_err(&pdev->dev, "Cannot get cfg data from DT or ACPI\n");
+		ret = -ENXIO;
 		goto err_registration;
 	}
 
-- 
2.17.1