PM: wakeup: Unify device_init_wakeup() for PM_SLEEP and !PM_SLEEP

Previously the CONFIG_PM_SLEEP and !CONFIG_PM_SLEEP device_init_wakeup()
implementations differed in confusing ways:

  - The PM_SLEEP version checked for a NULL device pointer and returned
    -EINVAL, while the !PM_SLEEP version did not and would simply
    dereference a NULL pointer.

  - When called with "false", the !PM_SLEEP version cleared "capable" and
    "enable" in the opposite order of the PM_SLEEP version.  That was
    harmless because for !PM_SLEEP they're simple assignments, but it's
    unnecessary confusion.

Use a simplified version of the PM_SLEEP implementation for both cases.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/base/power/wakeup.c

@@ -500,36 +500,6 @@ void device_set_wakeup_capable(struct device *dev, bool capable)
 }
 EXPORT_SYMBOL_GPL(device_set_wakeup_capable);
 
-/**
- * device_init_wakeup - Device wakeup initialization.
- * @dev: Device to handle.
- * @enable: Whether or not to enable @dev as a wakeup device.
- *
- * By default, most devices should leave wakeup disabled.  The exceptions are
- * devices that everyone expects to be wakeup sources: keyboards, power buttons,
- * possibly network interfaces, etc.  Also, devices that don't generate their
- * own wakeup requests but merely forward requests from one bus to another
- * (like PCI bridges) should have wakeup enabled by default.
- */
-int device_init_wakeup(struct device *dev, bool enable)
-{
-	int ret = 0;
-
-	if (!dev)
-		return -EINVAL;
-
-	if (enable) {
-		device_set_wakeup_capable(dev, true);
-		ret = device_wakeup_enable(dev);
-	} else {
-		device_wakeup_disable(dev);
-		device_set_wakeup_capable(dev, false);
-	}
-
-	return ret;
-}
-EXPORT_SYMBOL_GPL(device_init_wakeup);
-
 /**
  * device_set_wakeup_enable - Enable or disable a device to wake up the system.
  * @dev: Device to handle.

include/linux/pm_wakeup.h

@@ -109,7 +109,6 @@ extern struct wakeup_source *wakeup_sources_walk_next(struct wakeup_source *ws);
 extern int device_wakeup_enable(struct device *dev);
 extern int device_wakeup_disable(struct device *dev);
 extern void device_set_wakeup_capable(struct device *dev, bool capable);
-extern int device_init_wakeup(struct device *dev, bool val);
 extern int device_set_wakeup_enable(struct device *dev, bool enable);
 extern void __pm_stay_awake(struct wakeup_source *ws);
 extern void pm_stay_awake(struct device *dev);
@@ -167,13 +166,6 @@ static inline int device_set_wakeup_enable(struct device *dev, bool enable)
 	return 0;
 }
 
-static inline int device_init_wakeup(struct device *dev, bool val)
-{
-	device_set_wakeup_capable(dev, val);
-	device_set_wakeup_enable(dev, val);
-	return 0;
-}
-
 static inline bool device_may_wakeup(struct device *dev)
 {
 	return dev->power.can_wakeup && dev->power.should_wakeup;
@@ -217,4 +209,27 @@ static inline void pm_wakeup_hard_event(struct device *dev)
 	return pm_wakeup_dev_event(dev, 0, true);
 }
 
+/**
+ * device_init_wakeup - Device wakeup initialization.
+ * @dev: Device to handle.
+ * @enable: Whether or not to enable @dev as a wakeup device.
+ *
+ * By default, most devices should leave wakeup disabled.  The exceptions are
+ * devices that everyone expects to be wakeup sources: keyboards, power buttons,
+ * possibly network interfaces, etc.  Also, devices that don't generate their
+ * own wakeup requests but merely forward requests from one bus to another
+ * (like PCI bridges) should have wakeup enabled by default.
+ */
+static inline int device_init_wakeup(struct device *dev, bool enable)
+{
+	if (enable) {
+		device_set_wakeup_capable(dev, true);
+		return device_wakeup_enable(dev);
+	} else {
+		device_wakeup_disable(dev);
+		device_set_wakeup_capable(dev, false);
+		return 0;
+	}
+}
+
 #endif /* _LINUX_PM_WAKEUP_H */