usb: phy: Add interface to get phy give of device_node.

Split the "get phy from device_node" functionality out of
"get phy by phandle" so it can be used directly.

This is useful when a battery-charger is intimately associated with a
particular phy but handled by a separate driver.  The charger
can find the device_node based on sibling relationships
without the need for a redundant declaration in the devicetree
description.

As a peripheral that gets a phy will often want to register a
notifier block, and de-register it later, that functionality
is included so the de-registration is automatic.

Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>

2 files changed, 72 insertions, 27 deletions

diff --git a/drivers/usb/phy/phy.c b/drivers/usb/phy/phy.c
index d1cd6b50f520..98f75d2842b7 100644
--- a/drivers/usb/phy/phy.c
+++ b/drivers/usb/phy/phy.c
@@ -22,6 +22,11 @@ static LIST_HEAD(phy_list);
 static LIST_HEAD(phy_bind_list);
 static DEFINE_SPINLOCK(phy_lock);
 
+struct phy_devm {
+        struct usb_phy *phy;
+        struct notifier_block *nb;
+};
+
 static struct usb_phy *__usb_find_phy(struct list_head *list,
         enum usb_phy_type type)
 {
@@ -79,6 +84,15 @@ static void devm_usb_phy_release(struct device *dev, void *res)
         usb_put_phy(phy);
 }
 
+static void devm_usb_phy_release2(struct device *dev, void *_res)
+{
+        struct phy_devm *res = _res;
+
+        if (res->nb)
+                usb_unregister_notifier(res->phy, res->nb);
+        usb_put_phy(res->phy);
+}
+
 static int devm_usb_phy_match(struct device *dev, void *res, void *match_data)
 {
         struct usb_phy **phy = res;
@@ -153,40 +167,30 @@ err0:
 EXPORT_SYMBOL_GPL(usb_get_phy);
 
 /**
- * devm_usb_get_phy_by_phandle - find the USB PHY by phandle
+ * devm_usb_get_phy_by_node - find the USB PHY by device_node
  * @dev - device that requests this phy
- * @phandle - name of the property holding the phy phandle value
- * @index - the index of the phy
+ * @node - the device_node for the phy device.
+ * @nb - a notifier_block to register with the phy.
  *
- * Returns the phy driver associated with the given phandle value,
+ * Returns the phy driver associated with the given device_node,
  * after getting a refcount to it, -ENODEV if there is no such phy or
- * -EPROBE_DEFER if there is a phandle to the phy, but the device is
- * not yet loaded. While at that, it also associates the device with
+ * -EPROBE_DEFER if the device is not yet loaded. While at that, it
+ * also associates the device with
  * the phy using devres. On driver detach, release function is invoked
  * on the devres data, then, devres data is freed.
  *
- * For use by USB host and peripheral drivers.
+ * For use by peripheral drivers for devices related to a phy,
+ * such as a charger.
  */
-struct usb_phy *devm_usb_get_phy_by_phandle(struct device *dev,
-        const char *phandle, u8 index)
+struct  usb_phy *devm_usb_get_phy_by_node(struct device *dev,
+                                          struct device_node *node,
+                                          struct notifier_block *nb)
 {
-        struct usb_phy  *phy = ERR_PTR(-ENOMEM), **ptr;
+        struct usb_phy  *phy = ERR_PTR(-ENOMEM);
+        struct phy_devm *ptr;
         unsigned long   flags;
-        struct device_node *node;
 
-        if (!dev->of_node) {
-                dev_dbg(dev, "device does not have a device node entry\n");
-                return ERR_PTR(-EINVAL);
-        }
-
-        node = of_parse_phandle(dev->of_node, phandle, index);
-        if (!node) {
-                dev_dbg(dev, "failed to get %s phandle in %s node\n", phandle,
-                        dev->of_node->full_name);
-                return ERR_PTR(-ENODEV);
-        }
-
-        ptr = devres_alloc(devm_usb_phy_release, sizeof(*ptr), GFP_KERNEL);
+        ptr = devres_alloc(devm_usb_phy_release2, sizeof(*ptr), GFP_KERNEL);
         if (!ptr) {
                 dev_dbg(dev, "failed to allocate memory for devres\n");
                 goto err0;
@@ -205,8 +209,10 @@ struct usb_phy *devm_usb_get_phy_by_phandle(struct device *dev,
                 devres_free(ptr);
                 goto err1;
         }
-
-        *ptr = phy;
+        if (nb)
+                usb_register_notifier(phy, nb);
+        ptr->phy = phy;
+        ptr->nb = nb;
         devres_add(dev, ptr);
 
         get_device(phy->dev);
@@ -215,10 +221,47 @@ err1:
         spin_unlock_irqrestore(&phy_lock, flags);
 
 err0:
-        of_node_put(node);
 
         return phy;
 }
+EXPORT_SYMBOL_GPL(devm_usb_get_phy_by_node);
+
+/**
+ * devm_usb_get_phy_by_phandle - find the USB PHY by phandle
+ * @dev - device that requests this phy
+ * @phandle - name of the property holding the phy phandle value
+ * @index - the index of the phy
+ *
+ * Returns the phy driver associated with the given phandle value,
+ * after getting a refcount to it, -ENODEV if there is no such phy or
+ * -EPROBE_DEFER if there is a phandle to the phy, but the device is
+ * not yet loaded. While at that, it also associates the device with
+ * the phy using devres. On driver detach, release function is invoked
+ * on the devres data, then, devres data is freed.
+ *
+ * For use by USB host and peripheral drivers.
+ */
+struct usb_phy *devm_usb_get_phy_by_phandle(struct device *dev,
+        const char *phandle, u8 index)
+{
+        struct device_node *node;
+        struct usb_phy  *phy;
+
+        if (!dev->of_node) {
+                dev_dbg(dev, "device does not have a device node entry\n");
+                return ERR_PTR(-EINVAL);
+        }
+
+        node = of_parse_phandle(dev->of_node, phandle, index);
+        if (!node) {
+                dev_dbg(dev, "failed to get %s phandle in %s node\n", phandle,
+                        dev->of_node->full_name);
+                return ERR_PTR(-ENODEV);
+        }
+        phy = devm_usb_get_phy_by_node(dev, node, NULL);
+        of_node_put(node);
+        return phy;
+}
 EXPORT_SYMBOL_GPL(devm_usb_get_phy_by_phandle);
 
 /**
diff --git a/include/linux/usb/phy.h b/include/linux/usb/phy.h
index bc91b5d380fd..8ed1e29ef329 100644
--- a/include/linux/usb/phy.h
+++ b/include/linux/usb/phy.h
@@ -205,6 +205,8 @@ extern struct usb_phy *usb_get_phy_dev(struct device *dev, u8 index);
 extern struct usb_phy *devm_usb_get_phy_dev(struct device *dev, u8 index);
 extern struct usb_phy *devm_usb_get_phy_by_phandle(struct device *dev,
         const char *phandle, u8 index);
+extern struct usb_phy *devm_usb_get_phy_by_node(struct device *dev,
+        struct device_node *node, struct notifier_block *nb);
 extern void usb_put_phy(struct usb_phy *);
 extern void devm_usb_put_phy(struct device *dev, struct usb_phy *x);
 extern int usb_bind_phy(const char *dev_name, u8 index,