usb: core: split usb_phy_roothub_{init,alloc}

Before this patch usb_phy_roothub_init served two purposes (from a
caller's point of view - like hcd.c):
- parsing the PHYs and allocating the list entries
- calling phy_init on each list entry

While this worked so far it has one disadvantage: if we need to call
phy_init for each PHY instance then the existing code cannot be re-used.
Solve this by splitting off usb_phy_roothub_alloc which only parses the
PHYs and allocates the list entries.
usb_phy_roothub_init then gets a struct usb_phy_roothub and only calls
phy_init on each PHY instance (along with the corresponding cleanup if
that failed somewhere).

This is a preparation step for adding proper suspend support for some
hardware that requires phy_exit to be called during suspend and phy_init
to be called during resume.
Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Tested-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Reviewed-by: Roger Quadros <rogerq@ti.com>
Tested-by: Keerthy <j-keerthy@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/core/hcd.c

@@ -2759,12 +2759,16 @@ int usb_add_hcd(struct usb_hcd *hcd,
 	}
 
 	if (!hcd->skip_phy_initialization && usb_hcd_is_primary_hcd(hcd)) {
-		hcd->phy_roothub = usb_phy_roothub_init(hcd->self.sysdev);
+		hcd->phy_roothub = usb_phy_roothub_alloc(hcd->self.sysdev);
 		if (IS_ERR(hcd->phy_roothub)) {
 			retval = PTR_ERR(hcd->phy_roothub);
-			goto err_phy_roothub_init;
+			goto err_phy_roothub_alloc;
 		}
 
+		retval = usb_phy_roothub_init(hcd->phy_roothub);
+		if (retval)
+			goto err_phy_roothub_alloc;
+
 		retval = usb_phy_roothub_power_on(hcd->phy_roothub);
 		if (retval)
 			goto err_usb_phy_roothub_power_on;
@@ -2937,7 +2941,7 @@ int usb_add_hcd(struct usb_hcd *hcd,
 	usb_phy_roothub_power_off(hcd->phy_roothub);
 err_usb_phy_roothub_power_on:
 	usb_phy_roothub_exit(hcd->phy_roothub);
-err_phy_roothub_init:
+err_phy_roothub_alloc:
 	if (hcd->remove_phy && hcd->usb_phy) {
 		usb_phy_shutdown(hcd->usb_phy);
 		usb_put_phy(hcd->usb_phy);

drivers/usb/core/phy.c

@@ -19,19 +19,6 @@ struct usb_phy_roothub {
 	struct list_head	list;
 };
 
-static struct usb_phy_roothub *usb_phy_roothub_alloc(struct device *dev)
-{
-	struct usb_phy_roothub *roothub_entry;
-
-	roothub_entry = devm_kzalloc(dev, sizeof(*roothub_entry), GFP_KERNEL);
-	if (!roothub_entry)
-		return ERR_PTR(-ENOMEM);
-
-	INIT_LIST_HEAD(&roothub_entry->list);
-
-	return roothub_entry;
-}
-
 static int usb_phy_roothub_add_phy(struct device *dev, int index,
 				   struct list_head *list)
 {
@@ -45,9 +32,11 @@ static int usb_phy_roothub_add_phy(struct device *dev, int index,
 			return PTR_ERR(phy);
 	}
 
-	roothub_entry = usb_phy_roothub_alloc(dev);
-	if (IS_ERR(roothub_entry))
-		return PTR_ERR(roothub_entry);
+	roothub_entry = devm_kzalloc(dev, sizeof(*roothub_entry), GFP_KERNEL);
+	if (!roothub_entry)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&roothub_entry->list);
 
 	roothub_entry->phy = phy;
 
@@ -56,11 +45,9 @@ static int usb_phy_roothub_add_phy(struct device *dev, int index,
 	return 0;
 }
 
-struct usb_phy_roothub *usb_phy_roothub_init(struct device *dev)
+struct usb_phy_roothub *usb_phy_roothub_alloc(struct device *dev)
 {
 	struct usb_phy_roothub *phy_roothub;
-	struct usb_phy_roothub *roothub_entry;
-	struct list_head *head;
 	int i, num_phys, err;
 
 	num_phys = of_count_phandle_with_args(dev->of_node, "phys",
@@ -68,16 +55,31 @@ struct usb_phy_roothub *usb_phy_roothub_init(struct device *dev)
 	if (num_phys <= 0)
 		return NULL;
 
-	phy_roothub = usb_phy_roothub_alloc(dev);
-	if (IS_ERR(phy_roothub))
-		return phy_roothub;
+	phy_roothub = devm_kzalloc(dev, sizeof(*phy_roothub), GFP_KERNEL);
+	if (!phy_roothub)
+		return ERR_PTR(-ENOMEM);
+
+	INIT_LIST_HEAD(&phy_roothub->list);
 
 	for (i = 0; i < num_phys; i++) {
 		err = usb_phy_roothub_add_phy(dev, i, &phy_roothub->list);
 		if (err)
-			goto err_out;
+			return ERR_PTR(err);
 	}
 
+	return phy_roothub;
+}
+EXPORT_SYMBOL_GPL(usb_phy_roothub_alloc);
+
+int usb_phy_roothub_init(struct usb_phy_roothub *phy_roothub)
+{
+	struct usb_phy_roothub *roothub_entry;
+	struct list_head *head;
+	int err;
+
+	if (!phy_roothub)
+		return 0;
+
 	head = &phy_roothub->list;
 
 	list_for_each_entry(roothub_entry, head, list) {
@@ -86,14 +88,13 @@ struct usb_phy_roothub *usb_phy_roothub_init(struct device *dev)
 			goto err_exit_phys;
 	}
 
-	return phy_roothub;
+	return 0;
 
 err_exit_phys:
 	list_for_each_entry_continue_reverse(roothub_entry, head, list)
 		phy_exit(roothub_entry->phy);
 
-err_out:
-	return ERR_PTR(err);
+	return err;
 }
 EXPORT_SYMBOL_GPL(usb_phy_roothub_init);
 

drivers/usb/core/phy.h

 struct usb_phy_roothub;
 
-struct usb_phy_roothub *usb_phy_roothub_init(struct device *dev);
+struct usb_phy_roothub *usb_phy_roothub_alloc(struct device *dev);
+
+int usb_phy_roothub_init(struct usb_phy_roothub *phy_roothub);
 int usb_phy_roothub_exit(struct usb_phy_roothub *phy_roothub);
 
 int usb_phy_roothub_power_on(struct usb_phy_roothub *phy_roothub);