net: hns: register phy device in each mac initial sequence

In ACPI case, there is no interface to register phy device to mdio-bus.
Phy device has to be registered itself to mdio-bus, and then enet can
get the phy device's info so that it can config the phy-device to help
to trasmit and receive data.
HNS hardware topology is as below. The MDIO controller may control several
PHY-devices, and each PHY-device connects to a MAC device. PHY-devices
will register when each mac find PHY device in initial sequence.

                       cpu
                        |
                        |
     -------------------------------------------
    |                   |                       |
    |                   |                       |
    |                  dsaf                     |
   MDIO                 |                      MDIO
    |      ---------------------------          |
    |     |         |         |       |         |
    |     |         |         |       |         |
    |    MAC       MAC       MAC     MAC        |
    |     |         |         |       |         |
     ---- |-------- |-------- |       | --------
         ||        ||        ||       ||
         PHY       PHY       PHY     PHY
Signed-off-by: Kejian Yan <yankejian@huawei.com>
Signed-off-by: Yisen Zhuang <Yisen.Zhuang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/hns/hns_dsaf_mac.c

@@ -7,6 +7,7 @@
  * (at your option) any later version.
  */
 
+#include <linux/acpi.h>
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
@@ -638,6 +639,115 @@ static int hns_mac_init_ex(struct hns_mac_cb *mac_cb)
 	return ret;
 }
 
+static int
+hns_mac_phy_parse_addr(struct device *dev, struct fwnode_handle *fwnode)
+{
+	u32 addr;
+	int ret;
+
+	ret = fwnode_property_read_u32(fwnode, "phy-addr", &addr);
+	if (ret) {
+		dev_err(dev, "has invalid PHY address ret:%d\n", ret);
+		return ret;
+	}
+
+	if (addr >= PHY_MAX_ADDR) {
+		dev_err(dev, "PHY address %i is too large\n", addr);
+		return -EINVAL;
+	}
+
+	return addr;
+}
+
+static int hns_mac_phydev_match(struct device *dev, void *fwnode)
+{
+	return dev->fwnode == fwnode;
+}
+
+static struct
+platform_device *hns_mac_find_platform_device(struct fwnode_handle *fwnode)
+{
+	struct device *dev;
+
+	dev = bus_find_device(&platform_bus_type, NULL,
+			      fwnode, hns_mac_phydev_match);
+	return dev ? to_platform_device(dev) : NULL;
+}
+
+static int
+hns_mac_register_phydev(struct mii_bus *mdio, struct hns_mac_cb *mac_cb,
+			u32 addr)
+{
+	struct phy_device *phy;
+	const char *phy_type;
+	bool is_c45;
+	int rc;
+
+	rc = fwnode_property_read_string(mac_cb->fw_port,
+					 "phy-mode", &phy_type);
+	if (rc < 0)
+		return rc;
+
+	if (!strcmp(phy_type, phy_modes(PHY_INTERFACE_MODE_XGMII)))
+		is_c45 = 1;
+	else if (!strcmp(phy_type, phy_modes(PHY_INTERFACE_MODE_SGMII)))
+		is_c45 = 0;
+	else
+		return -ENODATA;
+
+	phy = get_phy_device(mdio, addr, is_c45);
+	if (!phy || IS_ERR(phy))
+		return -EIO;
+
+	if (mdio->irq)
+		phy->irq = mdio->irq[addr];
+
+	/* All data is now stored in the phy struct;
+	 * register it
+	 */
+	rc = phy_device_register(phy);
+	if (rc) {
+		phy_device_free(phy);
+		return -ENODEV;
+	}
+
+	mac_cb->phy_dev = phy;
+
+	dev_dbg(&mdio->dev, "registered phy at address %i\n", addr);
+
+	return 0;
+}
+
+static void hns_mac_register_phy(struct hns_mac_cb *mac_cb)
+{
+	struct acpi_reference_args args;
+	struct platform_device *pdev;
+	struct mii_bus *mii_bus;
+	int rc;
+	int addr;
+
+	/* Loop over the child nodes and register a phy_device for each one */
+	if (!to_acpi_device_node(mac_cb->fw_port))
+		return;
+
+	rc = acpi_node_get_property_reference(
+			mac_cb->fw_port, "mdio-node", 0, &args);
+	if (rc)
+		return;
+
+	addr = hns_mac_phy_parse_addr(mac_cb->dev, mac_cb->fw_port);
+	if (addr < 0)
+		return;
+
+	/* dev address in adev */
+	pdev = hns_mac_find_platform_device(acpi_fwnode_handle(args.adev));
+	mii_bus = platform_get_drvdata(pdev);
+	rc = hns_mac_register_phydev(mii_bus, mac_cb, addr);
+	if (!rc)
+		dev_dbg(mac_cb->dev, "mac%d register phy addr:%d\n",
+			mac_cb->mac_id, addr);
+}
+
 /**
  *hns_mac_get_info  - get mac information from device node
  *@mac_cb: mac device
@@ -691,9 +801,13 @@ static int  hns_mac_get_info(struct hns_mac_cb *mac_cb)
 
 	if (is_of_node(mac_cb->fw_port)) {
 		/* parse property from port subnode in dsaf */
-	np = of_parse_phandle(to_of_node(mac_cb->fw_port), "phy-handle", 0);
+		np = of_parse_phandle(to_of_node(mac_cb->fw_port),
+				      "phy-handle", 0);
 		mac_cb->phy_dev = of_phy_find_device(np);
 		if (mac_cb->phy_dev) {
+			/* refcount is held by of_phy_find_device()
+			 * if the phy_dev is found
+			 */
 			put_device(&mac_cb->phy_dev->mdio.dev);
 			dev_dbg(mac_cb->dev, "mac%d phy_node: %s\n",
 				mac_cb->mac_id, np->name);
@@ -743,6 +857,11 @@ static int  hns_mac_get_info(struct hns_mac_cb *mac_cb)
 				mac_cb->cpld_ctrl_reg = cpld_args.args[0];
 			}
 		}
+	} else if (is_acpi_node(mac_cb->fw_port)) {
+		hns_mac_register_phy(mac_cb);
+	} else {
+		dev_err(mac_cb->dev, "mac%d cannot find phy node\n",
+			mac_cb->mac_id);
 	}
 
 	return 0;