thermal:boost: Automatic enable/disable of BOOST feature

This patch provides auto disable/enable operation for boost. When any
defined trip point is passed, the boost is disabled.
In that moment thermal monitor workqueue is woken up and it monitors
if the device temperature drops below 75% of the smallest trip point.
When device cools down, the boost is enabled again.

Signed-off-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com>

Changes for v6:
- Disable boost only when supported and enabled
- Protect boost related thermal_zone_device struct fields with mutex
- Evaluate temperature trend during boost enable decision
- Create separate methods to handle boost enable/disable
  (thermal_boost_{enable|disable}) operations
- Boost is disabled at any trip point passage (not only the non critical one)

Changes for v5:
- Move boost disable code from cpu_cooling.c to thermal_core.c
  (to handle_non_critical_trips)
- Extent struct thermal_zone_device by adding overheated bool flag
- Implement auto enable of boost after device cools down
- Introduce boost_polling flag, which indicates if thermal uses it's predefined
  pool delay or has woken up thermal workqueue only to wait until device
  cools down.

Changes for v4:
- New patch

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/thermal.h b/include/linux/thermal.h
index a386a1cbb6e..f1aa3c23274 100644
--- a/include/linux/thermal.h
+++ b/include/linux/thermal.h
@@ -172,6 +172,8 @@ struct thermal_zone_device {
 	int emul_temperature;
 	int passive;
 	unsigned int forced_passive;
+	bool overheated;
+	bool boost_polling;
 	const struct thermal_zone_device_ops *ops;
 	const struct thermal_zone_params *tzp;
 	struct thermal_governor *governor;