Battery: align OS low battery shutdown behavior

Deprecate BATTERY_LEVEL_CRITICAL in battery logic and use
CONFIG_BATT_HOST_SHUTDOWN_PERCENTAGE instead to align
OS low battery shutdown behavior, and centralize the
low battery threshold decision.

LOW_COVERAGE_REASON=CONFIG_OCPC is per-board definition.
BRANCH=none
BUG=b:244253629
TEST=Verify dedede shutdown from resume on low battery.

Signed-off-by: Ivan Chen <yulunchen@google.com>
Change-Id: Ibab3f87f213cc23c54fb5d7dc95aa6366c98e94e
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3868875
Reviewed-by: Daisuke Nojiri <dnojiri@chromium.org>
Commit-Queue: Shou-Chieh Hsu <shouchieh@chromium.org>

5 files changed, 53 insertions, 14 deletions

diff --git a/common/battery_v1.c b/common/battery_v1.c
index e7507cf75d..2c81d6b446 100644
--- a/common/battery_v1.c
+++ b/common/battery_v1.c
@@ -155,8 +155,7 @@ void update_dynamic_battery_info(void)
 	}
 
 	if (curr->batt.is_present == BP_YES &&
-	    !(curr->batt.flags & BATT_FLAG_BAD_STATE_OF_CHARGE) &&
-	    curr->batt.state_of_charge <= BATTERY_LEVEL_CRITICAL)
+	    battery_is_below_threshold(BATT_THRESHOLD_TYPE_SHUTDOWN, false))
 		tmp |= EC_BATT_FLAG_LEVEL_CRITICAL;
 
 	tmp |= curr->batt_is_charging ? EC_BATT_FLAG_CHARGING :
diff --git a/common/battery_v2.c b/common/battery_v2.c
index 2bd274b465..57ae07196b 100644
--- a/common/battery_v2.c
+++ b/common/battery_v2.c
@@ -360,8 +360,7 @@ void update_dynamic_battery_info(void)
 	}
 
 	if (curr->batt.is_present == BP_YES &&
-	    !(curr->batt.flags & BATT_FLAG_BAD_STATE_OF_CHARGE) &&
-	    curr->batt.state_of_charge <= BATTERY_LEVEL_CRITICAL)
+	    battery_is_below_threshold(BATT_THRESHOLD_TYPE_SHUTDOWN, false))
 		tmp |= EC_BATT_FLAG_LEVEL_CRITICAL;
 
 	tmp |= curr->batt_is_charging ? EC_BATT_FLAG_CHARGING :
diff --git a/common/charge_state_v2.c b/common/charge_state_v2.c
index 9b567ba2ff..728606ef8a 100644
--- a/common/charge_state_v2.c
+++ b/common/charge_state_v2.c
@@ -1266,6 +1266,29 @@ static int shutdown_on_critical_battery(void)
 	return 1;
 }
 
+int battery_is_below_threshold(enum batt_threshold_type type, bool transitioned)
+{
+	int threshold;
+
+	/* We can't tell what the current charge is. Assume it's okay. */
+	if (curr.batt.flags & BATT_FLAG_BAD_STATE_OF_CHARGE)
+		return 0;
+
+	switch (type) {
+	case BATT_THRESHOLD_TYPE_LOW:
+		threshold = BATTERY_LEVEL_LOW;
+		break;
+	case BATT_THRESHOLD_TYPE_SHUTDOWN:
+		threshold = CONFIG_BATT_HOST_SHUTDOWN_PERCENTAGE;
+		break;
+	default:
+		return 0;
+	}
+
+	return curr.batt.state_of_charge <= threshold &&
+	       (!transitioned || prev_charge > threshold);
+}
+
 /*
  * Send host events as the battery charge drops below certain thresholds.
  * We handle forced shutdown and other actions elsewhere; this is just for the
@@ -1274,17 +1297,11 @@ static int shutdown_on_critical_battery(void)
  */
 static void notify_host_of_low_battery_charge(void)
 {
-	/* We can't tell what the current charge is. Assume it's okay. */
-	if (curr.batt.flags & BATT_FLAG_BAD_STATE_OF_CHARGE)
-		return;
-
 #ifdef CONFIG_HOSTCMD_EVENTS
-	if (curr.batt.state_of_charge <= BATTERY_LEVEL_LOW &&
-	    prev_charge > BATTERY_LEVEL_LOW)
+	if (battery_is_below_threshold(BATT_THRESHOLD_TYPE_LOW, true))
 		host_set_single_event(EC_HOST_EVENT_BATTERY_LOW);
 
-	if (curr.batt.state_of_charge <= BATTERY_LEVEL_CRITICAL &&
-	    prev_charge > BATTERY_LEVEL_CRITICAL)
+	if (battery_is_below_threshold(BATT_THRESHOLD_TYPE_SHUTDOWN, true))
 		host_set_single_event(EC_HOST_EVENT_BATTERY_CRITICAL);
 #endif
 }
diff --git a/include/charge_state.h b/include/charge_state.h
index c2d2bce948..221947b9d1 100644
--- a/include/charge_state.h
+++ b/include/charge_state.h
@@ -7,6 +7,7 @@
 
 #include "common.h"
 #include "timer.h"
+#include "stdbool.h"
 
 /* Stuff that's common to all charger implementations can go here. */
 
@@ -136,6 +137,27 @@ static inline int charge_want_shutdown(void)
 #endif
 
 /**
+ * Return true if battery level is below threshold, false otherwise,
+ * or if SoC can't be determined.
+ *
+ * @param transitioned	True to check if SoC is previously above threshold
+ */
+enum batt_threshold_type {
+	BATT_THRESHOLD_TYPE_LOW = 0,
+	BATT_THRESHOLD_TYPE_SHUTDOWN
+};
+#if defined(CONFIG_CHARGER) && defined(CONFIG_BATTERY)
+int battery_is_below_threshold(enum batt_threshold_type type,
+			       bool transitioned);
+#else
+static inline int battery_is_below_threshold(enum batt_threshold_type type,
+					     bool transitioned)
+{
+	return 0;
+}
+#endif
+
+/**
  * Return non-zero if the battery level is too low to allow power on, even if
  * a charger is attached.
  *
diff --git a/test/sbs_charging_v2.c b/test/sbs_charging_v2.c
index 1144a93368..b30f377c67 100644
--- a/test/sbs_charging_v2.c
+++ b/test/sbs_charging_v2.c
@@ -725,7 +725,8 @@ static int test_low_battery_hostevents(void)
 	TEST_ASSERT(!is_shutdown);
 
 	/* (Shout) a little bit louder now */
-	sb_write(SB_RELATIVE_STATE_OF_CHARGE, BATTERY_LEVEL_CRITICAL + 1);
+	sb_write(SB_RELATIVE_STATE_OF_CHARGE,
+		 CONFIG_BATT_HOST_SHUTDOWN_PERCENTAGE + 1);
 	state = wait_charging_state();
 	TEST_ASSERT(state == PWR_STATE_DISCHARGE);
 	TEST_ASSERT(ev_is_set(EC_HOST_EVENT_BATTERY_LOW));
@@ -734,7 +735,8 @@ static int test_low_battery_hostevents(void)
 	TEST_ASSERT(!is_shutdown);
 
 	/* (Shout) a little bit louder now */
-	sb_write(SB_RELATIVE_STATE_OF_CHARGE, BATTERY_LEVEL_CRITICAL - 1);
+	sb_write(SB_RELATIVE_STATE_OF_CHARGE,
+		 CONFIG_BATT_HOST_SHUTDOWN_PERCENTAGE - 1);
 	state = wait_charging_state();
 	TEST_ASSERT(state == PWR_STATE_DISCHARGE);
 	TEST_ASSERT(ev_is_set(EC_HOST_EVENT_BATTERY_LOW));