pm: device: add compatibility for force suspend and low power

Add support for FORCE_SUSPEND and LOW_POWER actions. Even though these
actions have no clear meaning, they are added for compatibility until
their associated states are discussed. Their usage in new code should be
discouraged until the associated states are clarified.

Signed-off-by: Gerard Marull-Paretas <[email protected]>

Author: gmarull

include/pm/device.h

@@ -78,6 +78,10 @@ enum pm_device_action {
 	PM_DEVICE_ACTION_RESUME,
 	/** Turn off. */
 	PM_DEVICE_ACTION_TURN_OFF,
+	/** Force suspend. */
+	PM_DEVICE_ACTION_FORCE_SUSPEND,
+	/** Low power. */
+	PM_DEVICE_ACTION_LOW_POWER,
 };
 
 /**

subsys/pm/device.c

@@ -158,9 +158,19 @@ int pm_device_state_set(const struct device *dev,
 		action = PM_DEVICE_ACTION_RESUME;
 		break;
 	case PM_DEVICE_STATE_FORCE_SUSPEND:
-		__fallthrough;
+		if (dev->pm->state == state) {
+			return -EALREADY;
+		}
+
+		action = PM_DEVICE_ACTION_FORCE_SUSPEND;
+		break;
 	case PM_DEVICE_STATE_LOW_POWER:
-		__fallthrough;
+		if (dev->pm->state == state) {
+			return -EALREADY;
+		}
+
+		action = PM_DEVICE_ACTION_LOW_POWER;
+		break;
 	case PM_DEVICE_STATE_OFF:
 		if (dev->pm->state == state) {
 			return -EALREADY;