net: dsa: realtek: convert variants into real drivers

Previously, the interface modules realtek-smi and realtek-mdio served as
a platform and an MDIO driver, respectively. Each interface module
redundantly specified the same compatible strings for both variants and
referenced symbols from the variants.

Now, each variant module has been transformed into a unified driver
serving both as a platform and an MDIO driver. This modification
reverses the relationship between the interface and variant modules,
with the variant module now utilizing symbols from the interface
modules.

Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 42 insertions, 26 deletions

diff --git a/drivers/net/dsa/realtek/realtek-mdio.c b/drivers/net/dsa/realtek/realtek-mdio.c
index c2572463679f..7c5372561587 100644
--- a/drivers/net/dsa/realtek/realtek-mdio.c
+++ b/drivers/net/dsa/realtek/realtek-mdio.c
@@ -25,6 +25,7 @@
 #include <linux/regmap.h>
 
 #include "realtek.h"
+#include "realtek-mdio.h"
 
 /* Read/write via mdiobus */
 #define REALTEK_MDIO_CTRL0_REG		31
@@ -140,7 +141,19 @@ static const struct regmap_config realtek_mdio_nolock_regmap_config = {
 	.disable_locking = true,
 };
 
-static int realtek_mdio_probe(struct mdio_device *mdiodev)
+/**
+ * realtek_mdio_probe() - Probe a platform device for an MDIO-connected switch
+ * @mdiodev: mdio_device to probe on.
+ *
+ * This function should be used as the .probe in an mdio_driver. It
+ * initializes realtek_priv and read data from the device-tree node. The switch
+ * is hard reset if a method is provided. It checks the switch chip ID and,
+ * finally, a DSA switch is registered.
+ *
+ * Context: Can sleep. Takes and releases priv->map_lock.
+ * Return: Returns 0 on success, a negative error on failure.
+ */
+int realtek_mdio_probe(struct mdio_device *mdiodev)
 {
 	struct realtek_priv *priv;
 	struct device *dev = &mdiodev->dev;
@@ -235,8 +248,20 @@ static int realtek_mdio_probe(struct mdio_device *mdiodev)
 
 	return 0;
 }
+EXPORT_SYMBOL_NS_GPL(realtek_mdio_probe, REALTEK_DSA);
 
-static void realtek_mdio_remove(struct mdio_device *mdiodev)
+/**
+ * realtek_mdio_remove() - Remove the driver of an MDIO-connected switch
+ * @mdiodev: mdio_device to be removed.
+ *
+ * This function should be used as the .remove_new in an mdio_driver. First
+ * it unregisters the DSA switch and cleans internal data. If a method is
+ * provided, the hard reset is asserted to avoid traffic leakage.
+ *
+ * Context: Can sleep.
+ * Return: Nothing.
+ */
+void realtek_mdio_remove(struct mdio_device *mdiodev)
 {
 	struct realtek_priv *priv = dev_get_drvdata(&mdiodev->dev);
 
@@ -249,8 +274,21 @@ static void realtek_mdio_remove(struct mdio_device *mdiodev)
 	if (priv->reset)
 		gpiod_set_value(priv->reset, 1);
 }
+EXPORT_SYMBOL_NS_GPL(realtek_mdio_remove, REALTEK_DSA);
 
-static void realtek_mdio_shutdown(struct mdio_device *mdiodev)
+/**
+ * realtek_mdio_shutdown() - Shutdown the driver of a MDIO-connected switch
+ * @mdiodev: mdio_device shutting down.
+ *
+ * This function should be used as the .shutdown in an mdio_driver. It shuts
+ * down the DSA switch and cleans the platform driver data, to prevent
+ * realtek_mdio_remove() from running afterwards, which is possible if the
+ * parent bus implements its own .shutdown() as .remove().
+ *
+ * Context: Can sleep.
+ * Return: Nothing.
+ */
+void realtek_mdio_shutdown(struct mdio_device *mdiodev)
 {
 	struct realtek_priv *priv = dev_get_drvdata(&mdiodev->dev);
 
@@ -261,29 +299,7 @@ static void realtek_mdio_shutdown(struct mdio_device *mdiodev)
 
 	dev_set_drvdata(&mdiodev->dev, NULL);
 }
-
-static const struct of_device_id realtek_mdio_of_match[] = {
-#if IS_ENABLED(CONFIG_NET_DSA_REALTEK_RTL8366RB)
-	{ .compatible = "realtek,rtl8366rb", .data = &rtl8366rb_variant, },
-#endif
-#if IS_ENABLED(CONFIG_NET_DSA_REALTEK_RTL8365MB)
-	{ .compatible = "realtek,rtl8365mb", .data = &rtl8365mb_variant, },
-#endif
-	{ /* sentinel */ },
-};
-MODULE_DEVICE_TABLE(of, realtek_mdio_of_match);
-
-static struct mdio_driver realtek_mdio_driver = {
-	.mdiodrv.driver = {
-		.name = "realtek-mdio",
-		.of_match_table = realtek_mdio_of_match,
-	},
-	.probe  = realtek_mdio_probe,
-	.remove = realtek_mdio_remove,
-	.shutdown = realtek_mdio_shutdown,
-};
-
-mdio_module_driver(realtek_mdio_driver);
+EXPORT_SYMBOL_NS_GPL(realtek_mdio_shutdown, REALTEK_DSA);
 
 MODULE_AUTHOR("Luiz Angelo Daros de Luca <luizluca@gmail.com>");
 MODULE_DESCRIPTION("Driver for Realtek ethernet switch connected via MDIO interface");