usb: common: usb-conn-gpio: fix NULL pointer dereference of charger

When power on system with OTG cable, IDDIG's interrupt arises before
the charger registration, it will cause a NULL pointer dereference,
fix the issue by registering the power supply before requesting
IDDIG/VBUS irq.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/1621406386-18838-1-git-send-email-chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/common/usb-conn-gpio.c

@@ -149,14 +149,32 @@ static int usb_charger_get_property(struct power_supply *psy,
 	return 0;
 }
 
-static int usb_conn_probe(struct platform_device *pdev)
+static int usb_conn_psy_register(struct usb_conn_info *info)
 {
-	struct device *dev = &pdev->dev;
-	struct power_supply_desc *desc;
-	struct usb_conn_info *info;
+	struct device *dev = info->dev;
+	struct power_supply_desc *desc = &info->desc;
 	struct power_supply_config cfg = {
 		.of_node = dev->of_node,
 	};
+
+	desc->name = "usb-charger";
+	desc->properties = usb_charger_properties;
+	desc->num_properties = ARRAY_SIZE(usb_charger_properties);
+	desc->get_property = usb_charger_get_property;
+	desc->type = POWER_SUPPLY_TYPE_USB;
+	cfg.drv_data = info;
+
+	info->charger = devm_power_supply_register(dev, desc, &cfg);
+	if (IS_ERR(info->charger))
+		dev_err(dev, "Unable to register charger\n");
+
+	return PTR_ERR_OR_ZERO(info->charger);
+}
+
+static int usb_conn_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct usb_conn_info *info;
 	bool need_vbus = true;
 	int ret = 0;
 
@@ -218,6 +236,10 @@ static int usb_conn_probe(struct platform_device *pdev)
 		return PTR_ERR(info->role_sw);
 	}
 
+	ret = usb_conn_psy_register(info);
+	if (ret)
+		goto put_role_sw;
+
 	if (info->id_gpiod) {
 		info->id_irq = gpiod_to_irq(info->id_gpiod);
 		if (info->id_irq < 0) {
@@ -252,20 +274,6 @@ static int usb_conn_probe(struct platform_device *pdev)
 		}
 	}
 
-	desc = &info->desc;
-	desc->name = "usb-charger";
-	desc->properties = usb_charger_properties;
-	desc->num_properties = ARRAY_SIZE(usb_charger_properties);
-	desc->get_property = usb_charger_get_property;
-	desc->type = POWER_SUPPLY_TYPE_USB;
-	cfg.drv_data = info;
-
-	info->charger = devm_power_supply_register(dev, desc, &cfg);
-	if (IS_ERR(info->charger)) {
-		dev_err(dev, "Unable to register charger\n");
-		return PTR_ERR(info->charger);
-	}
-
 	platform_set_drvdata(pdev, info);
 
 	/* Perform initial detection */