PM / wakeirq: support enabling wake-up irq after runtime_suspend called

When the dedicated wake IRQ is level trigger, and it uses the
device's low-power status as the wakeup source, that means if the
device is not in low-power state, the wake IRQ will be triggered
if enabled; For this case, need enable the wake IRQ after running
the device's ->runtime_suspend() which make it enter low-power state.

e.g.
Assume the wake IRQ is a low level trigger type, and the wakeup
signal comes from the low-power status of the device.
The wakeup signal is low level at running time (0), and becomes
high level when the device enters low-power state (runtime_suspend
(1) is called), a wakeup event at (2) make the device exit low-power
state, then the wakeup signal also becomes low level.

                ------------------
               |           ^     ^|
----------------           |     | --------------
 |<---(0)--->|<--(1)--|   (3)   (2)    (4)

if enable the wake IRQ before running runtime_suspend during (0),
a wake IRQ will arise, it causes resume immediately;
it works if enable wake IRQ ( e.g. at (3) or (4)) after running
->runtime_suspend().

This patch introduces a new status WAKE_IRQ_DEDICATED_REVERSE to
optionally support enabling wake IRQ after running ->runtime_suspend().

Suggested-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/include/linux/pm_wakeirq.h b/include/linux/pm_wakeirq.h
index cd5b62db9084..e63a63aa47a3 100644
--- a/include/linux/pm_wakeirq.h
+++ b/include/linux/pm_wakeirq.h
@@ -17,8 +17,8 @@
 #ifdef CONFIG_PM
 
 extern int dev_pm_set_wake_irq(struct device *dev, int irq);
-extern int dev_pm_set_dedicated_wake_irq(struct device *dev,
-					 int irq);
+extern int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq);
+extern int dev_pm_set_dedicated_wake_irq_reverse(struct device *dev, int irq);
 extern void dev_pm_clear_wake_irq(struct device *dev);
 extern void dev_pm_enable_wake_irq(struct device *dev);
 extern void dev_pm_disable_wake_irq(struct device *dev);
@@ -35,6 +35,11 @@ static inline int dev_pm_set_dedicated_wake_irq(struct device *dev, int irq)
 	return 0;
 }
 
+static inline int dev_pm_set_dedicated_wake_irq_reverse(struct device *dev, int irq)
+{
+	return 0;
+}
+
 static inline void dev_pm_clear_wake_irq(struct device *dev)
 {
 }