[openwrt/openwrt] realtek: mdio: convert mdio bus to new device nodes and compatibles

[LEDE Commits]

hauke pushed a commit to openwrt/openwrt.git, branch main:
https://git.openwrt.org/616559b6d3ed92b55ce3a9727782f3a3fbbda6c6

commit 616559b6d3ed92b55ce3a9727782f3a3fbbda6c6
Author: Markus Stockhausen <markus.stockhausen at gmx.de>
AuthorDate: Mon Sep 8 05:19:30 2025 -0400

    realtek: mdio: convert mdio bus to new device nodes and compatibles
    
    The mdio controller has now its own target specific device nodes. This
    is much closer to upstream notation. Adapt the driver to make use of it.
    
    Signed-off-by: Markus Stockhausen <markus.stockhausen at gmx.de>
    Link: https://github.com/openwrt/openwrt/pull/19986
    Signed-off-by: Hauke Mehrtens <hauke at hauke-m.de>
---
 .../files-6.12/drivers/net/dsa/rtl83xx/common.c    | 21 ++++-----
 .../drivers/net/mdio/mdio-realtek-otto.c           | 50 +++++++++-------------
 2 files changed, 31 insertions(+), 40 deletions(-)

diff --git a/target/linux/realtek/files-6.12/drivers/net/dsa/rtl83xx/common.c b/target/linux/realtek/files-6.12/drivers/net/dsa/rtl83xx/common.c
index 80b36ec5a8..c955669a23 100644
--- a/target/linux/realtek/files-6.12/drivers/net/dsa/rtl83xx/common.c
+++ b/target/linux/realtek/files-6.12/drivers/net/dsa/rtl83xx/common.c
@@ -268,24 +268,27 @@ static int rtldsa_bus_c45_write(struct mii_bus *bus, int addr, int devad, int re
 
 static int __init rtl83xx_mdio_probe(struct rtl838x_switch_priv *priv)
 {
+	struct device_node *dn, *phy_node, *led_node, *np, *mii_np;
 	struct device *dev = priv->dev;
-	struct device_node *dn, *phy_node, *led_node, *mii_np = dev->of_node;
 	struct mii_bus *bus;
 	int ret;
 	u32 pn;
 
-	pr_debug("In %s\n", __func__);
-	mii_np = of_find_compatible_node(NULL, NULL, "realtek,rtl838x-mdio");
-	if (mii_np) {
-		pr_debug("Found compatible MDIO node!\n");
-	} else {
-		dev_err(priv->dev, "no %s child node found", "mdio-bus");
+	np = of_find_compatible_node(NULL, NULL, "realtek,rtl838x-eth");
+	if (!np) {
+		dev_err(priv->dev, "ethernet node not found");
+		return -ENODEV;
+	}
+
+	mii_np = of_get_child_by_name(np, "mdio-bus");
+	if (!mii_np) {
+		dev_err(priv->dev, "mdio-bus subnode not found");
 		return -ENODEV;
 	}
 
 	priv->parent_bus = of_mdio_find_bus(mii_np);
 	if (!priv->parent_bus) {
-		pr_debug("Deferring probe of mdio bus\n");
+		dev_dbg(priv->dev, "Deferring probe of mdio bus\n");
 		return -EPROBE_DEFER;
 	}
 	if (!of_device_is_available(mii_np))
@@ -419,8 +422,6 @@ static int __init rtl83xx_mdio_probe(struct rtl838x_switch_priv *priv)
 		rtl8380_sds_power(26, 1);
 	}
 
-	pr_debug("%s done\n", __func__);
-
 	return 0;
 }
 
diff --git a/target/linux/realtek/files-6.12/drivers/net/mdio/mdio-realtek-otto.c b/target/linux/realtek/files-6.12/drivers/net/mdio/mdio-realtek-otto.c
index 216273d19d..0bb5e361af 100644
--- a/target/linux/realtek/files-6.12/drivers/net/mdio/mdio-realtek-otto.c
+++ b/target/linux/realtek/files-6.12/drivers/net/mdio/mdio-realtek-otto.c
@@ -1397,16 +1397,29 @@ static int rtmdio_get_family(void)
 
 static int rtmdio_probe(struct platform_device *pdev)
 {
+	struct device_node *dn, *np, *mii_np;
 	struct device *dev = &pdev->dev;
 	struct rtmdio_bus_priv *priv;
-	struct device_node *dn;
 	struct mii_bus *bus;
-	int i, ret, family;
+	int i, family;
 	u32 pn;
 
 	family = rtmdio_get_family();
 	dev_info(dev, "probing RTL%04x family mdio bus\n", family);
 
+	np = of_find_compatible_node(NULL, NULL, "realtek,rtl838x-eth");
+	if (!np)
+		return -ENODEV;
+
+	mii_np = of_get_child_by_name(np, "mdio-bus");
+	if (!mii_np)
+		return -ENODEV;
+
+	if (!of_device_is_available(mii_np)) {
+		of_node_put(mii_np);
+		return -ENODEV;
+	}
+
 	bus = devm_mdiobus_alloc_size(dev, sizeof(*priv));
 	if (!bus)
 		return -ENOMEM;
@@ -1536,14 +1549,15 @@ static int rtmdio_probe(struct platform_device *pdev)
 	}
 
 	snprintf(bus->id, MII_BUS_ID_SIZE, "%s-mii", dev_name(dev));
-	ret = devm_of_mdiobus_register(dev, bus, dev->of_node);
 
-	return ret;
+	return devm_of_mdiobus_register(dev, bus, mii_np);
 }
 
-
 static const struct of_device_id rtmdio_ids[] = {
-	{ .compatible = "realtek,rtl838x-mdio" },
+	{ .compatible = "realtek,rtl8380-mdio" },
+	{ .compatible = "realtek,rtl8392-mdio" },
+	{ .compatible = "realtek,rtl9301-mdio" },
+	{ .compatible = "realtek,rtl9311-mdio" },
 	{}
 };
 MODULE_DEVICE_TABLE(of, rtmdio_ids);
@@ -1558,29 +1572,5 @@ static struct platform_driver rtmdio_driver = {
 
 module_platform_driver(rtmdio_driver);
 
-/*
- * TODO: The below initialization function is only needed because the mdio bus
- * is a subnode of the ethernet node. That means detection via platform driver
- * will not work out of the box. Until this is solved, populate the platform
- * data manually.
- */
-static int __init rtmdio_init(void)
-{
-	struct device_node *np;
-
-	np = of_find_compatible_node(NULL, NULL, "realtek,rtl838x-eth");
-	if (!np) {
-		pr_err("realtek,rtl838x-eth compatible device not found\n");
-		return -ENODEV;
-	}
-
-	pr_info("populating rtl838x-mdio device manually\n");
-	of_platform_populate(np, NULL, NULL, NULL);
-	of_node_put(np);
-
-	return 0;
-}
-module_init(rtmdio_init);
-
 MODULE_DESCRIPTION("RTL83xx/RTL93xx MDIO driver");
 MODULE_LICENSE("GPL");