charge_state_v2: Hibernate base in S5 with no AC

Tell the base to hibernate when we are in S5, and no AC is connected.
Also, wake the base when AC status changes (S5), and when the system
transistions out of S5.

BRANCH=none
BUG=b:71874971
TEST=1. Lid EC console: apshutdown => Check that Base EC hibernates
     2.a. Lid EC console: powerb; => Check that base reconnects
     2.b. Connect/disconnect adapter: check that base disconnects
          and reconnects

Change-Id: I5e9a4afc64a07ad92f37d171a78a914d26f07c8e
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/958814
Reviewed-by: Randall Spangler <rspangler@chromium.org>

1 files changed, 29 insertions, 5 deletions

diff --git a/common/charge_state_v2.c b/common/charge_state_v2.c
index a5e8aea37e..c62627ca5a 100644
--- a/common/charge_state_v2.c
+++ b/common/charge_state_v2.c
@@ -393,7 +393,7 @@ static void set_base_lid_current(int current_base, int allow_charge_base,
 	 * Make sure cross-power is enabled (it might not be enabled right after
 	 * plugging the base, or when an adapter just got connected).
 	 */
-	if (base_connected)
+	if (base_connected && current_base != 0)
 		board_enable_base_power(1);
 }
 
@@ -500,15 +500,30 @@ static void charge_allocate_input_current_limit(void)
 		}
 
 		/*
-		 * System is suspended/off, let the lid and base run on their
+		 * System is off, cut power to the base. We'll reset the base
+		 * when system restarts, or when AC is plugged.
+		 */
+		if (chipset_in_state(CHIPSET_STATE_ANY_OFF)) {
+			set_base_lid_current(0, 0, 0, 0);
+			if (base_responsive) {
+				/* Base still responsive, put it to sleep. */
+				CPRINTF("Hibernating base\n");
+				ec_ec_master_hibernate();
+				base_responsive = 0;
+				board_enable_base_power(0);
+			}
+			return;
+		}
+
+		/*
+		 * System is suspended, let the lid and base run on their
 		 * own power. However, if the base battery is critically low, we
 		 * still want to provide power to the base, to make sure it
 		 * stays alive to be able to wake the system on keyboard or
 		 * touchpad events.
 		 */
-		if (chipset_in_state(CHIPSET_STATE_ANY_OFF) ||
-				(chipset_in_state(CHIPSET_STATE_ANY_SUSPEND) &&
-				 !base_critical)) {
+		if (chipset_in_state(CHIPSET_STATE_ANY_SUSPEND) &&
+					!base_critical) {
 			set_base_lid_current(0, 0, 0, 0);
 			return;
 		}
@@ -1337,6 +1352,10 @@ static void charge_wakeup(void)
 DECLARE_HOOK(HOOK_CHIPSET_RESUME, charge_wakeup, HOOK_PRIO_DEFAULT);
 DECLARE_HOOK(HOOK_AC_CHANGE, charge_wakeup, HOOK_PRIO_DEFAULT);
 
+#ifdef CONFIG_EC_EC_COMM_BATTERY_MASTER
+/* Reset the base on S5->S0 transition. */
+DECLARE_HOOK(HOOK_CHIPSET_STARTUP, board_base_reset, HOOK_PRIO_DEFAULT);
+#endif
 
 static int get_desired_input_current(enum battery_present batt_present,
 				     const struct charger_info * const info)
@@ -1406,6 +1425,11 @@ void charger_task(void *u)
 		 */
 		if (base_responsive && prev_current_base < 0)
 			curr.ac = 0;
+
+		/* System is off: if AC gets connected, reset the base. */
+		if (chipset_in_state(CHIPSET_STATE_ANY_OFF) &&
+				!prev_ac && curr.ac)
+			board_base_reset();
 #endif
 		if (curr.ac != prev_ac) {
 			if (curr.ac) {