PM / Wakeirq: Add automated device wake IRQ handling

Turns out we can automate the handling for the device_may_wakeup()
quite a bit by using the kernel wakeup source list as suggested
by Rafael J. Wysocki <rjw@rjwysocki.net>.

And as some hardware has separate dedicated wake-up interrupt
in addition to the IO interrupt, we can automate the handling by
adding a generic threaded interrupt handler that just calls the
device PM runtime to wake up the device.

This allows dropping code from device drivers as we currently
are doing it in multiple ways, and often wrong.

For most drivers, we should be able to drop the following
boilerplate code from runtime_suspend and runtime_resume
functions:

	...
	device_init_wakeup(dev, true);
	...
	if (device_may_wakeup(dev))
		enable_irq_wake(irq);
	...
	if (device_may_wakeup(dev))
		disable_irq_wake(irq);
	...
	device_init_wakeup(dev, false);
	...

We can replace it with just the following init and exit
time code:

	...
	device_init_wakeup(dev, true);
	dev_pm_set_wake_irq(dev, irq);
	...
	dev_pm_clear_wake_irq(dev);
	device_init_wakeup(dev, false);
	...

And for hardware with dedicated wake-up interrupts:

	...
	device_init_wakeup(dev, true);
	dev_pm_set_dedicated_wake_irq(dev, irq);
	...
	dev_pm_clear_wake_irq(dev);
	device_init_wakeup(dev, false);
	...

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 52 insertions, 0 deletions

diff --git a/include/linux/pm_wakeirq.h b/include/linux/pm_wakeirq.h
new file mode 100644
index 000000000000..4046fa1b7d25
--- /dev/null
+++ b/include/linux/pm_wakeirq.h
@@ -0,0 +1,52 @@
+/*
+ * pm_wakeirq.h - Device wakeirq helper functions
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef _LINUX_PM_WAKEIRQ_H
+#define _LINUX_PM_WAKEIRQ_H
+
+#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 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);
+
+#else	/* !CONFIG_PM */
+
+static inline int dev_pm_set_wake_irq(struct device *dev, int irq)
+{
+	return 0;
+}
+
+static inline int dev_pm_set_dedicated__wake_irq(struct device *dev,
+						 int irq)
+{
+	return 0;
+}
+
+static inline void dev_pm_clear_wake_irq(struct device *dev)
+{
+}
+
+static inline void dev_pm_enable_wake_irq(struct device *dev)
+{
+}
+
+static inline void dev_pm_disable_wake_irq(struct device *dev)
+{
+}
+
+#endif	/* CONFIG_PM */
+#endif	/* _LINUX_PM_WAKEIRQ_H */