Fizz: Switch power source to BJ at G3/S5

This patch allows Fizz to switch the power source from a type-c
charger to a barrel jack adapter if the system is in S5.

BUG=b:38321259
BRANCH=none
TEST=Verify the following with 45W and 60W type-c chargers:
1. Boot Fizz with a type-c charger
2. Go to S5 if not already.
3. Plug in a BJ adapter. Fizz boots to S0 using BJ power.

Also verified other boot modes are not affected:
1. Auto boot on BJ insert
2. Auto boot on Type-C insert
3. Recovery boot on BJ
4. Recovery boot on Type-C
5. Stay off if it's previously S5

Change-Id: I86aa0fe6e403bcbacfe396997d897111ffcf8e74
Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/706251
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>

4 files changed, 45 insertions, 8 deletions

diff --git a/board/fizz/board.c b/board/fizz/board.c
index ce0ff98920..918d38892d 100644
--- a/board/fizz/board.c
+++ b/board/fizz/board.c
@@ -71,20 +71,38 @@ static void tcpc_alert_event(enum gpio_signal signal)
  */
 static int adp_in_state = 1;
 
+static void adp_in_deferred(void);
+DECLARE_DEFERRED(adp_in_deferred);
 static void adp_in_deferred(void)
 {
-	/* TODO: Switch power source from USB-C to BJ only if we're in S5. */
-	struct charge_port_info cpi;
+	struct charge_port_info pi = { 0 };
 	int level = gpio_get_level(GPIO_ADP_IN_L);
 
 	/* Debounce */
 	if (level == adp_in_state)
 		return;
-	/* High = unplugged. Low = plugged. TODO: Set appropriate voltage. */
-	cpi.voltage = level ? 0 : 19000;
-	/* Set to 0 to ensure charge manager will ignore it. */
-	cpi.current = 0;
-	charge_manager_update_charge(CHARGE_SUPPLIER_DEDICATED, 1, &cpi);
+	if (!level) {
+		/* BJ is inserted but the voltage isn't effective because PU3
+		 * is still disabled. */
+		pi.voltage = 19000;
+		if (chipset_in_state(CHIPSET_STATE_ANY_OFF)) {
+			/* If type-c voltage is higher than BJ voltage, PU3 will
+			 * shut down due to reverse current protection. So, we
+			 * need to lower the voltage first. */
+			if (charge_manager_get_charger_voltage() > pi.voltage) {
+				pd_set_external_voltage_limit(
+						CHARGE_PORT_TYPEC0, pi.voltage);
+				hook_call_deferred(&adp_in_deferred_data,
+						   ADP_DEBOUNCE_MS * MSEC);
+				return;
+			}
+			if (gpio_get_level(GPIO_POWER_RATE))
+				pi.current = 4620;
+			else
+				pi.current = 3330;
+		}
+	}
+	charge_manager_update_charge(CHARGE_SUPPLIER_DEDICATED, 1, &pi);
 	/*
 	 * Explicitly notifies the host that BJ is plugged or unplugged
 	 * (when running on a type-c adapter).
@@ -92,7 +110,6 @@ static void adp_in_deferred(void)
 	pd_send_host_event(PD_EVENT_POWER_CHANGE);
 	adp_in_state = level;
 }
-DECLARE_DEFERRED(adp_in_deferred);
 
 /* IRQ for BJ plug/unplug. It shouldn't be called if BJ is the power source. */
 void adp_in(enum gpio_signal signal)
diff --git a/board/fizz/usb_pd_policy.c b/board/fizz/usb_pd_policy.c
index 39e47dd895..5dc807cc82 100644
--- a/board/fizz/usb_pd_policy.c
+++ b/board/fizz/usb_pd_policy.c
@@ -289,6 +289,14 @@ int board_set_active_charge_port(int port)
 		break;
 	case CHARGE_PORT_BARRELJACK :
 		gpio_set_level(GPIO_AC_JACK_CHARGE_L, 0);
+		/* If this is switching from type-c to BJ, we have to wait until
+		 * PU3 comes up to keep the system continuously powered.
+		 * NX20P5090 datasheet says turn-on time for 20V is 29 msec. */
+		if (active_port == CHARGE_PORT_TYPEC0)
+			msleep(30);
+		/* We don't check type-c voltage here. If it's higher than
+		 * BJ voltage, we'll brown out due to the reverse current
+		 * protection of PU3. */
 		gpio_set_level(GPIO_USB_C0_CHARGE_L, 1);
 		gpio_disable_interrupt(GPIO_ADP_IN_L);
 		break;
diff --git a/common/charge_manager.c b/common/charge_manager.c
index a068897620..4a6808b50f 100644
--- a/common/charge_manager.c
+++ b/common/charge_manager.c
@@ -995,6 +995,11 @@ int charge_manager_get_charger_current(void)
 	return charge_current;
 }
 
+int charge_manager_get_charger_voltage(void)
+{
+	return charge_voltage;
+}
+
 int charge_manager_get_power_limit_uw(void)
 {
 	int current_ma = charge_current;
diff --git a/include/charge_manager.h b/include/charge_manager.h
index 6d5bacc2df..0f2624129e 100644
--- a/include/charge_manager.h
+++ b/include/charge_manager.h
@@ -162,6 +162,13 @@ int charge_manager_get_power_limit_uw(void);
  */
 int charge_manager_get_charger_current(void);
 
+/**
+ * Get the charger voltage (mV) value.
+ *
+ * @return	Charger voltage (mV) or CHARGE_VOLTAGE_UNINITIALIZED.
+ */
+int charge_manager_get_charger_voltage(void);
+
 #ifdef CONFIG_USB_PD_LOGGING
 /* Save power state log entry for the given port */
 void charge_manager_save_log(int port);