power/mt8183: Hold PMIC enable to force S5->G3 transition.

Asserting VSYSSNS should only be done as a last measure. If the
PMIC is configured properly, it will shut down upon holding
POWER+HOME key for 8+ seconds. This is shorter than the S5->G3
timeout, so we should never need to assert VSYSSNS.

BRANCH=none
BUG=b:134912821
TEST=reboot ap-off, immediately powerb, see that AP turns on and
     stays on.
TEST=apshutdown, PMIC shuts off gracefully
TEST=In power/common.c, change S5_INACTIVITY_TIMEOUT to 3 seconds,
     see that state machines forces PMIC off using VSYSSNS.
TEST=Boot DUT: mosys eventlog clear; poweroff
     power on DUT, run dut-control power_state:off
     Wait 8 seconds for EC to go to G3, power on DUT again
     mosys eventlog list shows events with correct time stamps:
0 | 2019-06-14 15:44:31 | Log area cleared | 79
1 | 2019-06-14 15:44:38 | System boot | 0
2 | 2019-06-14 15:44:38 | Chrome OS Developer Mode
3 | 2019-06-14 15:45:13 | System boot | 0
4 | 2019-06-14 15:45:13 | Chrome OS Developer Mode

Change-Id: I9b73d06e07296e47e15fe87dd87fffac2af04d12
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1660073
Reviewed-by: Daisuke Nojiri <dnojiri@chromium.org>

1 files changed, 31 insertions, 3 deletions

diff --git a/power/mt8183.c b/power/mt8183.c
index e005cb0288..0be256cb89 100644
--- a/power/mt8183.c
+++ b/power/mt8183.c
@@ -254,7 +254,23 @@ enum power_state power_handle_state(enum power_state state)
 			return POWER_S5S3;
 		}
 
-		/* Stay in S5, common code will drop to G3 after timeout. */
+		/* Forcing shutdown */
+
+		/* Long press has worked, transition to G3. */
+		if (!(power_get_signals() & IN_PGOOD_PMIC))
+			return POWER_S5G3;
+
+		/*
+		 * Try to force PMIC shutdown with a long press. This takes 8s,
+		 * shorter than the common code S5->G3 timeout (10s).
+		 */
+		CPRINTS("Forcing shutdown with long press.");
+		gpio_set_level(GPIO_PMIC_EN_ODL, 0);
+
+		/*
+		 * Stay in S5, common code will drop to G3 after timeout
+		 * if the long press does not work.
+		 */
 		return POWER_S5;
 
 	case POWER_S3:
@@ -282,8 +298,15 @@ enum power_state power_handle_state(enum power_state state)
 		return POWER_S5;
 
 	case POWER_S5S3:
+		/*
+		 * Release power button in case it was pressed by force shutdown
+		 * sequence.
+		 */
+		gpio_set_level(GPIO_PMIC_EN_ODL, 1);
+
 		/* If PMIC is off, switch it on by pulsing PMIC enable. */
 		if (!(power_get_signals() & IN_PGOOD_PMIC)) {
+			msleep(PMIC_EN_PULSE_MS);
 			gpio_set_level(GPIO_PMIC_EN_ODL, 0);
 			msleep(PMIC_EN_PULSE_MS);
 			gpio_set_level(GPIO_PMIC_EN_ODL, 1);
@@ -391,11 +414,16 @@ enum power_state power_handle_state(enum power_state state)
 		return POWER_S5;
 
 	case POWER_S5G3:
+		/* Release the power button, in case it was long pressed. */
+		if (forcing_shutdown)
+			gpio_set_level(GPIO_PMIC_EN_ODL, 1);
+
 		/*
 		 * If PMIC is still not off, assert PMIC_FORCE_RESET_ODL.
 		 * This should only happen for forced shutdown where the AP is
-		 * not able to send a command to the PMIC. Also, PMIC will lose
-		 * RTC state, in that case.
+		 * not able to send a command to the PMIC, and where the long
+		 * power+home press did not work (if the PMIC is misconfigured).
+		 * Also, PMIC will lose RTC state, in that case.
 		 */
 		if (power_get_signals() & IN_PGOOD_PMIC) {
 			CPRINTS("Forcing PMIC off");