phy: core: add notify_connect and notify_disconnect callback

In Realtek SoC, the parameter of usb phy is designed to be able to
do dynamic tuning based in the port status. Therefore, add a notify
callback of phy driver when usb connection/disconnection change.
Signed-off-by: Stanley Chang <stanley_chang@realtek.com>
Link: https://lore.kernel.org/r/20231213031203.4911-1-stanley_chang@realtek.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/phy/phy-core.c

@@ -489,6 +489,53 @@ int phy_calibrate(struct phy *phy)
 }
 EXPORT_SYMBOL_GPL(phy_calibrate);
 
+/**
+ * phy_notify_connect() - phy connect notification
+ * @phy: the phy returned by phy_get()
+ * @port: the port index for connect
+ *
+ * If the phy needs to get connection status, the callback can be used.
+ * Returns: %0 if successful, a negative error code otherwise
+ */
+int phy_notify_connect(struct phy *phy, int port)
+{
+	int ret;
+
+	if (!phy || !phy->ops->connect)
+		return 0;
+
+	mutex_lock(&phy->mutex);
+	ret = phy->ops->connect(phy, port);
+	mutex_unlock(&phy->mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(phy_notify_connect);
+
+/**
+ * phy_notify_disconnect() - phy disconnect notification
+ * @phy: the phy returned by phy_get()
+ * @port: the port index for disconnect
+ *
+ * If the phy needs to get connection status, the callback can be used.
+ *
+ * Returns: %0 if successful, a negative error code otherwise
+ */
+int phy_notify_disconnect(struct phy *phy, int port)
+{
+	int ret;
+
+	if (!phy || !phy->ops->disconnect)
+		return 0;
+
+	mutex_lock(&phy->mutex);
+	ret = phy->ops->disconnect(phy, port);
+	mutex_unlock(&phy->mutex);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(phy_notify_disconnect);
+
 /**
  * phy_configure() - Changes the phy parameters
  * @phy: the phy returned by phy_get()

include/linux/phy/phy.h

@@ -122,6 +122,11 @@ struct phy_ops {
 			    union phy_configure_opts *opts);
 	int	(*reset)(struct phy *phy);
 	int	(*calibrate)(struct phy *phy);
+
+	/* notify phy connect status change */
+	int	(*connect)(struct phy *phy, int port);
+	int	(*disconnect)(struct phy *phy, int port);
+
 	void	(*release)(struct phy *phy);
 	struct module *owner;
 };
@@ -243,6 +248,8 @@ static inline enum phy_mode phy_get_mode(struct phy *phy)
 }
 int phy_reset(struct phy *phy);
 int phy_calibrate(struct phy *phy);
+int phy_notify_connect(struct phy *phy, int port);
+int phy_notify_disconnect(struct phy *phy, int port);
 static inline int phy_get_bus_width(struct phy *phy)
 {
 	return phy->attrs.bus_width;
@@ -396,6 +403,20 @@ static inline int phy_calibrate(struct phy *phy)
 	return -ENOSYS;
 }
 
+static inline int phy_notify_connect(struct phy *phy, int index)
+{
+	if (!phy)
+		return 0;
+	return -ENOSYS;
+}
+
+static inline int phy_notify_disconnect(struct phy *phy, int index)
+{
+	if (!phy)
+		return 0;
+	return -ENOSYS;
+}
+
 static inline int phy_configure(struct phy *phy,
 				union phy_configure_opts *opts)
 {