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>

3 files changed, 63 insertions, 0 deletions

diff --git a/include/linux/pm.h b/include/linux/pm.h
index 2d29c64f8fb1..1c4ed0cb7907 100644
--- a/include/linux/pm.h
+++ b/include/linux/pm.h
@@ -529,6 +529,7 @@ enum rpm_request {
 };
 
 struct wakeup_source;
+struct wake_irq;
 struct pm_domain_data;
 
 struct pm_subsys_data {
@@ -568,6 +569,7 @@ struct dev_pm_info {
 	unsigned long		timer_expires;
 	struct work_struct	work;
 	wait_queue_head_t	wait_queue;
+	struct wake_irq		*wakeirq;
 	atomic_t		usage_count;
 	atomic_t		child_count;
 	unsigned int		disable_depth:3;
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 */
diff --git a/include/linux/pm_wakeup.h b/include/linux/pm_wakeup.h
index a0f70808d7f4..a3447932df1f 100644
--- a/include/linux/pm_wakeup.h
+++ b/include/linux/pm_wakeup.h
@@ -28,9 +28,17 @@
 
 #include <linux/types.h>
 
+struct wake_irq;
+
 /**
  * struct wakeup_source - Representation of wakeup sources
  *
+ * @name: Name of the wakeup source
+ * @entry: Wakeup source list entry
+ * @lock: Wakeup source lock
+ * @wakeirq: Optional device specific wakeirq
+ * @timer: Wakeup timer list
+ * @timer_expires: Wakeup timer expiration
  * @total_time: Total time this wakeup source has been active.
  * @max_time: Maximum time this wakeup source has been continuously active.
  * @last_time: Monotonic clock when the wakeup source's was touched last time.
@@ -47,6 +55,7 @@ struct wakeup_source {
 	const char 		*name;
 	struct list_head	entry;
 	spinlock_t		lock;
+	struct wake_irq		*wakeirq;
 	struct timer_list	timer;
 	unsigned long		timer_expires;
 	ktime_t total_time;