power_supply: Prevent suspend until power supply events are processed

This patch, originally authored by Arve Hjonnevag and Todd Poynor,
prevents the system from entering suspend mode until the power supply
plug, unplug, or any other change of state event is fully processed. This
guarantees that the screen lights up and displays the battery charging
state. The implementation uses the power supply wakeup_source object.

Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Arve Hjonnevag <arve@android.com>
Cc: Todd Poynor <toddpoynor@google.com>
Cc: John Stultz <john.stultz@linaro.org>
Signed-off-by: Zoran Markovic <zoran.markovic@linaro.org>
Signed-off-by: Anton Vorontsov <anton@enomsg.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/linux/power_supply.h b/include/linux/power_supply.h
index 804b90643a85..5c2600630dc9 100644
--- a/include/linux/power_supply.h
+++ b/include/linux/power_supply.h
@@ -15,6 +15,7 @@
 
 #include <linux/workqueue.h>
 #include <linux/leds.h>
+#include <linux/spinlock.h>
 
 struct device;
 
@@ -194,6 +195,8 @@ struct power_supply {
         /* private */
         struct device *dev;
         struct work_struct changed_work;
+        spinlock_t changed_lock;
+        bool changed;
 #ifdef CONFIG_THERMAL
         struct thermal_zone_device *tzd;
         struct thermal_cooling_device *tcd;