[PATCH net-next RFC 2/3] net: dsa: realtek: deprecate custom slave mii

[Luiz Angelo Daros de Luca <luizluca@gmail.com>]

The custom slave mii was required only to parse the OF mdio node.
However, since fe7324b932, the standard slave mii created by dsa already
looks for an "mdio" node.

The realtek-smi was using a compatible string ("realtek,smi-mdio") to
find the slave mdio node. Although device-tree bindings and examples all
use "mdio". If the name does not match "mdio", the driver will still use
the custom mii slave. The driver will also ask to remove the compatible
string if it exists in the "mdio" node.

After a grace period, we can remove:
- realtek_variant.ds_ops_custom_slavemii
- realtek_ops.phy_{read,write}
- realtek_ops.setup_interface
- {rtl8365mb,rtl8366rb}_phy_{read,write}
- realtek_smi_setup_mdio

Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
---
 drivers/net/dsa/realtek/realtek-smi.c | 21 ++++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)

diff --git a/drivers/net/dsa/realtek/realtek-smi.c b/drivers/net/dsa/realtek/realtek-smi.c
index 3eb9d67fd2de..c3668a9208ac 100644
--- a/drivers/net/dsa/realtek/realtek-smi.c
+++ b/drivers/net/dsa/realtek/realtek-smi.c
@@ -379,6 +379,10 @@ static int realtek_smi_setup_mdio(struct dsa_switch *ds)
 		return -ENODEV;
 	}
 
+	dev_warn(priv->dev,
+		 "Rename '%s' to 'mdio' and remove the compatible string\n",
+		  mdio_np->full_name);
+
 	priv->slave_mii_bus = devm_mdiobus_alloc(priv->dev);
 	if (!priv->slave_mii_bus) {
 		ret = -ENOMEM;
@@ -412,10 +416,10 @@ static int realtek_smi_setup_mdio(struct dsa_switch *ds)
 static int realtek_smi_probe(struct platform_device *pdev)
 {
 	const struct realtek_variant *var;
+	struct device_node *np, *mdio_np;
 	struct device *dev = &pdev->dev;
 	struct realtek_priv *priv;
 	struct regmap_config rc;
-	struct device_node *np;
 	int ret;
 
 	var = of_device_get_match_data(dev);
@@ -452,7 +456,6 @@ static int realtek_smi_probe(struct platform_device *pdev)
 	priv->cmd_write = var->cmd_write;
 	priv->ops = var->ops;
 
-	priv->setup_interface = realtek_smi_setup_mdio;
 	priv->write_reg_noack = realtek_smi_write_reg_noack;
 
 	dev_set_drvdata(dev, priv);
@@ -497,8 +500,20 @@ static int realtek_smi_probe(struct platform_device *pdev)
 	priv->ds->dev = dev;
 	priv->ds->num_ports = priv->num_ports;
 	priv->ds->priv = priv;
+	priv->ds->ops = var->ds_ops;
+
+	mdio_np = of_get_child_by_name(np, "mdio");
+	if (mdio_np) {
+		if (of_device_is_compatible(mdio_np, "realtek,smi-mdio"))
+			dev_warn(dev, "Remove deprecated prop '%s' from '%s'",
+				 "compatible = \"realtek,smi-mdio\"",
+				 mdio_np->full_name);
+		of_node_put(mdio_np);
+	} else {
+		priv->ds->ops = var->ds_ops_custom_slavemii;
+		priv->setup_interface = realtek_smi_setup_mdio;
+	}
 
-	priv->ds->ops = var->ds_ops_custom_slavemii;
 	ret = dsa_register_switch(priv->ds);
 	if (ret) {
 		dev_err_probe(dev, ret, "unable to register switch\n");
-- 
2.36.1