yorp: renegotiate Vbus down before hibernating

When we support the lowest power mode for Nuvoton in the next spin, we
will shed the TCPC/PPC power rail during hibernate. Before we drop the
power for the PPCs we need to ensure that Vbus is lower than the
hard-coded 6.8V dead-battery mode over-voltage threshold, otherwise we
will lock ourselves out of power.

BRANCH=none
BUG=b:79218851
TEST=verified that yorp renegotiates Vbus to 5V when entering hibernate
via ec `hibernate` cmd.

Change-Id: I4a98573eefb5757eea02dc48c64d5f9358b5e0b7
Signed-off-by: Jett Rink <jettrink@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1047954
Reviewed-by: Furquan Shaikh <furquan@chromium.org>

1 files changed, 46 insertions, 0 deletions

diff --git a/baseboard/octopus/variant_ec_npcx796fb.c b/baseboard/octopus/variant_ec_npcx796fb.c
index f85184738d..6c839cbb10 100644
--- a/baseboard/octopus/variant_ec_npcx796fb.c
+++ b/baseboard/octopus/variant_ec_npcx796fb.c
@@ -5,9 +5,15 @@
 
 /* Common code for VARIANT_OCTOPUS_EC_NPCX796FB configuration */
 
+#include "charge_manager.h"
+#include "chipset.h"
 #include "gpio.h"
 #include "i2c.h"
+#include "power.h"
+#include "usb_pd.h"
+#include "usbc_ppc.h"
 #include "util.h"
+#include "timer.h"
 
 /******************************************************************************/
 /* I2C port map configuration */
@@ -20,3 +26,43 @@ const struct i2c_port_t i2c_ports[] = {
 	{"sensor",  I2C_PORT_SENSOR,  100, GPIO_I2C7_SCL, GPIO_I2C7_SDA},
 };
 const unsigned int i2c_ports_used = ARRAY_SIZE(i2c_ports);
+
+#define HIBERNATE_VBUS_LEVEL_MV	5000
+
+void board_hibernate(void)
+{
+	int port;
+
+	/*
+	 * To support hibernate called from console commands, ectool commands
+	 * and key sequence, shutdown the AP before hibernating.
+	 */
+	chipset_force_shutdown();
+
+	/*
+	 * If we are charging, then drop the Vbus level down to 5V to ensure
+	 * that we don't get locked out of the 6.8V OVLO for our PPCs in
+	 * dead-battery mode. This is needed when the TCPC/PPC rails go away.
+	 * (b/79218851)
+	 */
+	port = charge_manager_get_active_charge_port();
+	if (port != CHARGE_PORT_NONE)
+		pd_request_source_voltage(port, HIBERNATE_VBUS_LEVEL_MV);
+
+	/*
+	 * Delay allows AP power state machine to settle down along
+	 * with any PD contract renegotiation.
+	 */
+	msleep(100);
+
+	for (port = 0; port < CONFIG_USB_PD_PORT_COUNT; port++) {
+		/*
+		 * If Vbus isn't already on this port, then open the SNK path
+		 * to allow AC to pass through to the charger when connected.
+		 * This is need if the TCPC/PPC rails do not go away.
+		 * (b/79173959)
+		 */
+		if (!pd_is_vbus_present(port))
+			ppc_vbus_sink_enable(port, 1);
+	}
+}