reef: Enable BD9995X power save mode when hibernated

Turn off the charger BGATE when the system is hibernated to
save maximum power.

BUG=chrome-os-partner:59001
BRANCH=none
TEST=Manually verified on the Reef.
     System can boot from hibernate wake sources.
     Following are the power measurement values at Battery
     voltage = 8.3V & temperature = 23 deg C.
     a. Normal operation 540uA, 3.500mW
     b. BGATE OFF        80uA, 0.592mW

Change-Id: Ia30655ccefbf0dded623246150d53b2a815df2de
Signed-off-by: Vijay Hiremath <vijay.p.hiremath@intel.com>
Reviewed-on: https://chromium-review.googlesource.com/404685
Commit-Ready: Vijay P Hiremath <vijay.p.hiremath@intel.com>
Tested-by: Vijay P Hiremath <vijay.p.hiremath@intel.com>
Reviewed-by: Shawn N <shawnn@chromium.org>

3 files changed, 19 insertions, 12 deletions

diff --git a/board/reef/board.c b/board/reef/board.c
index 68d3e5f95c..87bc929d60 100644
--- a/board/reef/board.c
+++ b/board/reef/board.c
@@ -918,6 +918,9 @@ void board_hibernate(void)
 
 	/* Enable both the VBUS & VCC ports before entering PG3 */
 	bd9995x_select_input_port(BD9995X_CHARGE_PORT_BOTH, 1);
+
+	/* Turn BGATE OFF for saving the power */
+	bd9995x_set_power_save_mode(BD9995X_PWR_SAVE_MAX);
 }
 
 struct {
diff --git a/driver/charger/bd9995x.c b/driver/charger/bd9995x.c
index 675afafe90..137cd25b6f 100644
--- a/driver/charger/bd9995x.c
+++ b/driver/charger/bd9995x.c
@@ -630,7 +630,6 @@ int charger_set_voltage(int voltage)
 static void bd99995_init(void)
 {
 	int reg;
-	int power_save_mode = BD9995X_PWR_SAVE_OFF;
 	const struct battery_info *bi = battery_get_info();
 
 	/* Enable BC1.2 detection on VCC */
@@ -708,10 +707,10 @@ static void bd99995_init(void)
 
 	/* Power save mode when VBUS/VCC is removed. */
 #ifdef CONFIG_BD9995X_POWER_SAVE_MODE
-	power_save_mode = CONFIG_BD9995X_POWER_SAVE_MODE;
+	bd9995x_set_power_save_mode(CONFIG_BD9995X_POWER_SAVE_MODE);
+#else
+	bd9995x_set_power_save_mode(BD9995X_PWR_SAVE_OFF);
 #endif
-	ch_raw_write16(BD9995X_CMD_SMBREG, power_save_mode,
-		       BD9995X_EXTENDED_COMMAND);
 
 #ifdef CONFIG_USB_PD_DISCHARGE
 	/* Set VBUS / VCC detection threshold for discharge enable */
@@ -855,6 +854,11 @@ int bd9995x_get_battery_temp(int *temp_ptr)
 }
 #endif
 
+void bd9995x_set_power_save_mode(int mode)
+{
+	ch_raw_write16(BD9995X_CMD_SMBREG, mode, BD9995X_EXTENDED_COMMAND);
+}
+
 #ifdef HAS_TASK_USB_CHG
 int bd9995x_get_bc12_ilim(int charge_supplier)
 {
@@ -913,23 +917,21 @@ int bd9995x_bc12_enable_charging(enum bd9995x_charge_port port, int enable)
 
 void usb_charger_set_switches(int port, enum usb_switch setting)
 {
-	int power_save_mode = BD9995X_PWR_SAVE_OFF;
-
 	/* If switch is not changing then return */
 	if (setting == usb_switch_state[port])
 		return;
 
 	if (setting != USB_SWITCH_RESTORE)
 		usb_switch_state[port] = setting;
+
 	/* ensure we disable power saving when we are using DP/DN */
 #ifdef CONFIG_BD9995X_POWER_SAVE_MODE
-	power_save_mode = (usb_switch_state[0] == USB_SWITCH_DISCONNECT &&
-			   usb_switch_state[1] == USB_SWITCH_DISCONNECT)
-			   ? CONFIG_BD9995X_POWER_SAVE_MODE
-			   : BD9995X_PWR_SAVE_OFF;
+	bd9995x_set_power_save_mode(
+		(usb_switch_state[0] == USB_SWITCH_DISCONNECT &&
+		usb_switch_state[1] == USB_SWITCH_DISCONNECT)
+		? CONFIG_BD9995X_POWER_SAVE_MODE : BD9995X_PWR_SAVE_OFF);
 #endif
-	ch_raw_write16(BD9995X_CMD_SMBREG, power_save_mode,
-		       BD9995X_EXTENDED_COMMAND);
+
 	bd9995x_enable_usb_switch(port, usb_switch_state[port]);
 }
 
diff --git a/driver/charger/bd9995x.h b/driver/charger/bd9995x.h
index ea27b88715..a9538b5dc0 100644
--- a/driver/charger/bd9995x.h
+++ b/driver/charger/bd9995x.h
@@ -357,6 +357,8 @@ int bd9995x_bc12_enable_charging(enum bd9995x_charge_port port, int enable);
 void bd9995x_vbus_interrupt(enum gpio_signal signal);
 /* Read temperature measurement value (in Celsius) */
 int bd9995x_get_battery_temp(int *temp_ptr);
+/* Set power save mode */
+void bd9995x_set_power_save_mode(int mode);
 
 #ifdef CONFIG_CMD_I2C_STRESS_TEST_CHARGER
 extern struct i2c_stress_test_dev bd9995x_i2c_stress_test_dev;