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From: Luiz Angelo Daros de Luca <luizluca@gmail.com>
Date: Tue, 30 Jan 2024 20:13:28 -0300
Subject: [PATCH net-next v5 09/11] net: dsa: realtek: migrate user_mii_bus
 setup to realtek-dsa
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Message-Id: <20240130-realtek_reverse-v5-9-ecafd9283a07@gmail.com>
References: <20240130-realtek_reverse-v5-0-ecafd9283a07@gmail.com>
In-Reply-To: <20240130-realtek_reverse-v5-0-ecafd9283a07@gmail.com>
To: Linus Walleij <linus.walleij@linaro.org>, 
 =?utf-8?q?Alvin_=C5=A0ipraga?= <alsi@bang-olufsen.dk>, 
 Andrew Lunn <andrew@lunn.ch>, Florian Fainelli <f.fainelli@gmail.com>, 
 Vladimir Oltean <olteanv@gmail.com>, 
 "David S. Miller" <davem@davemloft.net>, Eric Dumazet <edumazet@google.com>, 
 Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>, 
 Russell King <linux@armlinux.org.uk>
Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, 
 Luiz Angelo Daros de Luca <luizluca@gmail.com>

In the user MDIO driver, despite numerous references to SMI, including
its compatible string, there's nothing inherently specific about the SMI
interface in the user MDIO bus. Consequently, the code has been migrated
to the rtl83xx module. All references to SMI have been eliminated.

The MDIO bus id was changed from Realtek-<switch id> to the switch
devname suffixed with :user_mii, giving more information about the bus
it is referencing.

Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
---
 drivers/net/dsa/realtek/realtek-smi.c | 57 +----------------------------
 drivers/net/dsa/realtek/rtl83xx.c     | 69 +++++++++++++++++++++++++++++++++++
 drivers/net/dsa/realtek/rtl83xx.h     |  1 +
 3 files changed, 71 insertions(+), 56 deletions(-)

diff --git a/drivers/net/dsa/realtek/realtek-smi.c b/drivers/net/dsa/realtek/realtek-smi.c
index b84df4564c15..4d35621b5583 100644
--- a/drivers/net/dsa/realtek/realtek-smi.c
+++ b/drivers/net/dsa/realtek/realtek-smi.c
@@ -31,7 +31,6 @@
 #include <linux/spinlock.h>
 #include <linux/skbuff.h>
 #include <linux/of.h>
-#include <linux/of_mdio.h>
 #include <linux/delay.h>
 #include <linux/gpio/consumer.h>
 #include <linux/platform_device.h>
@@ -312,60 +311,6 @@ static int realtek_smi_read(void *ctx, u32 reg, u32 *val)
 	return realtek_smi_read_reg(priv, reg, val);
 }
 
-static int realtek_smi_mdio_read(struct mii_bus *bus, int addr, int regnum)
-{
-	struct realtek_priv *priv = bus->priv;
-
-	return priv->ops->phy_read(priv, addr, regnum);
-}
-
-static int realtek_smi_mdio_write(struct mii_bus *bus, int addr, int regnum,
-				  u16 val)
-{
-	struct realtek_priv *priv = bus->priv;
-
-	return priv->ops->phy_write(priv, addr, regnum, val);
-}
-
-static int realtek_smi_setup_mdio(struct dsa_switch *ds)
-{
-	struct realtek_priv *priv =  ds->priv;
-	struct device_node *mdio_np;
-	int ret = 0;
-
-	mdio_np = of_get_child_by_name(priv->dev->of_node, "mdio");
-	if (!mdio_np) {
-		dev_err(priv->dev, "no MDIO bus node\n");
-		return -ENODEV;
-	}
-
-	priv->user_mii_bus = devm_mdiobus_alloc(priv->dev);
-	if (!priv->user_mii_bus) {
-		ret = -ENOMEM;
-		goto err_put_node;
-	}
-
-	priv->user_mii_bus->priv = priv;
-	priv->user_mii_bus->name = "SMI user MII";
-	priv->user_mii_bus->read = realtek_smi_mdio_read;
-	priv->user_mii_bus->write = realtek_smi_mdio_write;
-	snprintf(priv->user_mii_bus->id, MII_BUS_ID_SIZE, "SMI-%d",
-		 ds->index);
-	priv->user_mii_bus->parent = priv->dev;
-
-	ret = devm_of_mdiobus_register(priv->dev, priv->user_mii_bus, mdio_np);
-	if (ret) {
-		dev_err(priv->dev, "unable to register MDIO bus %s\n",
-			priv->user_mii_bus->id);
-		goto err_put_node;
-	}
-
-err_put_node:
-	of_node_put(mdio_np);
-
-	return ret;
-}
-
 static const struct realtek_interface_info realtek_smi_info = {
 	.reg_read = realtek_smi_read,
 	.reg_write = realtek_smi_write,
@@ -403,7 +348,7 @@ int realtek_smi_probe(struct platform_device *pdev)
 		return PTR_ERR(priv->mdio);
 
 	priv->write_reg_noack = realtek_smi_write_reg_noack;
-	priv->setup_interface = realtek_smi_setup_mdio;
+	priv->setup_interface = rtl83xx_setup_user_mdio;
 	priv->ds_ops = priv->variant->ds_ops_smi;
 
 	ret = rtl83xx_register_switch(priv);
diff --git a/drivers/net/dsa/realtek/rtl83xx.c b/drivers/net/dsa/realtek/rtl83xx.c
index fb3b3b2305d1..f05fe6efe5a4 100644
--- a/drivers/net/dsa/realtek/rtl83xx.c
+++ b/drivers/net/dsa/realtek/rtl83xx.c
@@ -2,6 +2,7 @@
 
 #include <linux/module.h>
 #include <linux/regmap.h>
+#include <linux/of_mdio.h>
 
 #include "realtek.h"
 #include "rtl83xx.h"
@@ -43,6 +44,74 @@ void rtl83xx_unlock(void *ctx)
 }
 EXPORT_SYMBOL_NS_GPL(rtl83xx_unlock, REALTEK_DSA);
 
+static int rtl83xx_user_mdio_read(struct mii_bus *bus, int addr, int regnum)
+{
+	struct realtek_priv *priv = bus->priv;
+
+	return priv->ops->phy_read(priv, addr, regnum);
+}
+
+static int rtl83xx_user_mdio_write(struct mii_bus *bus, int addr, int regnum,
+				   u16 val)
+{
+	struct realtek_priv *priv = bus->priv;
+
+	return priv->ops->phy_write(priv, addr, regnum, val);
+}
+
+/**
+ * rtl83xx_setup_user_mdio() - register the user mii bus driver
+ * @ds: DSA switch associated with this user_mii_bus
+ *
+ * This function first gets and mdio node under the dev OF node, aborting
+ * if missing. That mdio node describing an mdio bus is used to register a
+ * new mdio bus.
+ *
+ * Context: Can sleep.
+ * Return: 0 on success, negative value for failure.
+ */
+int rtl83xx_setup_user_mdio(struct dsa_switch *ds)
+{
+	struct realtek_priv *priv = ds->priv;
+	struct device_node *mdio_np;
+	struct mii_bus *bus;
+	int ret = 0;
+
+	mdio_np = of_get_child_by_name(priv->dev->of_node, "mdio");
+	if (!mdio_np) {
+		dev_err(priv->dev, "no MDIO bus node\n");
+		return -ENODEV;
+	}
+
+	bus = devm_mdiobus_alloc(priv->dev);
+	if (!bus) {
+		ret = -ENOMEM;
+		goto err_put_node;
+	}
+
+	bus->priv = priv;
+	bus->name = "Realtek user MII";
+	bus->read = rtl83xx_user_mdio_read;
+	bus->write = rtl83xx_user_mdio_write;
+	snprintf(bus->id, MII_BUS_ID_SIZE, "%s:user_mii", dev_name(priv->dev));
+	bus->parent = priv->dev;
+
+	ret = devm_of_mdiobus_register(priv->dev, bus, mdio_np);
+	if (ret) {
+		dev_err(priv->dev, "unable to register MDIO bus %s\n",
+			bus->id);
+		goto err_put_node;
+	}
+
+	priv->user_mii_bus = bus;
+
+err_put_node:
+	of_node_put(mdio_np);
+
+	return ret;
+}
+EXPORT_SYMBOL_NS_GPL(rtl83xx_setup_user_mdio, REALTEK_DSA);
+
 /**
  * rtl83xx_probe() - probe a Realtek switch
  * @dev: the device being probed
diff --git a/drivers/net/dsa/realtek/rtl83xx.h b/drivers/net/dsa/realtek/rtl83xx.h
index a8eed92bce1a..0ddff33df6b0 100644
--- a/drivers/net/dsa/realtek/rtl83xx.h
+++ b/drivers/net/dsa/realtek/rtl83xx.h
@@ -10,6 +10,7 @@ struct realtek_interface_info {
 
 void rtl83xx_lock(void *ctx);
 void rtl83xx_unlock(void *ctx);
+int rtl83xx_setup_user_mdio(struct dsa_switch *ds);
 struct realtek_priv *
 rtl83xx_probe(struct device *dev,
 	      const struct realtek_interface_info *interface_info);

-- 
2.43.0