SM5803: add suspend/resume function for S0ix state

add function to turn on/off features in SM5803 charger
during S0ix state to save power. we are seeing ~8mW power
saving per charger.

BRANCH=None
BUG=b:168591511
TEST=Check power saving in S0ix state and check charger and device
functionality after resume.

Signed-off-by: Divagar Mohandass <divagar.mohandass@intel.com>
Change-Id: I3ea32219040263f0abef8b9dd4c52edb31289fd7
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2409485
Reviewed-by: Aseda Aboagye <aaboagye@chromium.org>

4 files changed, 153 insertions, 0 deletions

diff --git a/board/drawcia/board.c b/board/drawcia/board.c
index 3adcbb819a..1b872683fa 100644
--- a/board/drawcia/board.c
+++ b/board/drawcia/board.c
@@ -424,6 +424,22 @@ void board_init(void)
 }
 DECLARE_HOOK(HOOK_INIT, board_init, HOOK_PRIO_DEFAULT);
 
+static void board_resume(void)
+{
+	sm5803_disable_low_power_mode(CHARGER_PRIMARY);
+	if (board_get_charger_chip_count() > 1)
+		sm5803_disable_low_power_mode(CHARGER_SECONDARY);
+}
+DECLARE_HOOK(HOOK_CHIPSET_RESUME, board_resume, HOOK_PRIO_DEFAULT);
+
+static void board_suspend(void)
+{
+	sm5803_enable_low_power_mode(CHARGER_PRIMARY);
+	if (board_get_charger_chip_count() > 1)
+		sm5803_enable_low_power_mode(CHARGER_SECONDARY);
+}
+DECLARE_HOOK(HOOK_CHIPSET_SUSPEND, board_suspend, HOOK_PRIO_DEFAULT);
+
 void board_hibernate(void)
 {
 	/*
diff --git a/board/waddledee/board.c b/board/waddledee/board.c
index 96f0b8841c..9a4b8432cc 100644
--- a/board/waddledee/board.c
+++ b/board/waddledee/board.c
@@ -270,6 +270,22 @@ void board_init(void)
 }
 DECLARE_HOOK(HOOK_INIT, board_init, HOOK_PRIO_DEFAULT);
 
+static void board_resume(void)
+{
+	sm5803_disable_low_power_mode(CHARGER_PRIMARY);
+	if (board_get_charger_chip_count() > 1)
+		sm5803_disable_low_power_mode(CHARGER_SECONDARY);
+}
+DECLARE_HOOK(HOOK_CHIPSET_RESUME, board_resume, HOOK_PRIO_DEFAULT);
+
+static void board_suspend(void)
+{
+	sm5803_enable_low_power_mode(CHARGER_PRIMARY);
+	if (board_get_charger_chip_count() > 1)
+		sm5803_enable_low_power_mode(CHARGER_SECONDARY);
+}
+DECLARE_HOOK(HOOK_CHIPSET_SUSPEND, board_suspend, HOOK_PRIO_DEFAULT);
+
 void board_hibernate(void)
 {
 	/*
diff --git a/driver/charger/sm5803.c b/driver/charger/sm5803.c
index 30f9826ff6..207404f96f 100644
--- a/driver/charger/sm5803.c
+++ b/driver/charger/sm5803.c
@@ -702,6 +702,123 @@ void sm5803_hibernate(int chgnum)
 		CPRINTS("%s %d: Failed to set hibernate", CHARGER_NAME, chgnum);
 }
 
+static void sm5803_disable_runtime_low_power_mode(void)
+{
+	enum ec_error_list rv;
+	int reg;
+	int chgnum = TASK_ID_TO_PD_PORT(task_get_current());
+
+	CPRINTS("%s %d: disable runtime low power mode", CHARGER_NAME, chgnum);
+	rv = main_read8(chgnum, SM5803_REG_REFERENCE, &reg);
+	if (rv) {
+		CPRINTS("%s %d: Failed to read REFERENCE reg", CHARGER_NAME,
+			chgnum);
+		return;
+	}
+	/* Set a higher clock speed */
+	rv |= main_read8(chgnum, SM5803_REG_CLOCK_SEL, &reg);
+	reg &= ~SM5803_CLOCK_SEL_LOW;
+	rv |= main_write8(chgnum, SM5803_REG_CLOCK_SEL, reg);
+
+	/* Enable ADC sigma delta */
+	rv |= chg_read8(chgnum, SM5803_REG_CC_CONFIG1, &reg);
+	reg |= SM5803_CC_CONFIG1_SD_PWRUP;
+	rv |= chg_write8(chgnum, SM5803_REG_CC_CONFIG1, reg);
+
+	if (rv)
+		CPRINTS("%s %d: Failed to set in disable runtime LPM",
+			CHARGER_NAME, chgnum);
+}
+DECLARE_HOOK(HOOK_USB_PD_CONNECT,
+		sm5803_disable_runtime_low_power_mode,
+		HOOK_PRIO_FIRST);
+
+static void sm5803_enable_runtime_low_power_mode(void)
+{
+	enum ec_error_list rv;
+	int reg;
+	int chgnum = TASK_ID_TO_PD_PORT(task_get_current());
+
+	CPRINTS("%s %d: enable runtime low power mode", CHARGER_NAME, chgnum);
+	rv = main_read8(chgnum, SM5803_REG_REFERENCE, &reg);
+	if (rv) {
+		CPRINTS("%s %d: Failed to read REFERENCE reg", CHARGER_NAME,
+			chgnum);
+		return;
+	}
+	/* Slow the clock speed */
+	rv |= main_read8(chgnum, SM5803_REG_CLOCK_SEL, &reg);
+	reg |= SM5803_CLOCK_SEL_LOW;
+	rv |= main_write8(chgnum, SM5803_REG_CLOCK_SEL, reg);
+
+	/* Disable ADC sigma delta */
+	rv |= chg_read8(chgnum, SM5803_REG_CC_CONFIG1, &reg);
+	reg &= ~SM5803_CC_CONFIG1_SD_PWRUP;
+	rv |= chg_write8(chgnum, SM5803_REG_CC_CONFIG1, reg);
+
+	if (rv)
+		CPRINTS("%s %d: Failed to set in enable runtime LPM",
+			CHARGER_NAME, chgnum);
+}
+DECLARE_HOOK(HOOK_USB_PD_DISCONNECT,
+		sm5803_enable_runtime_low_power_mode,
+		HOOK_PRIO_LAST);
+
+void sm5803_disable_low_power_mode(int chgnum)
+{
+	enum ec_error_list rv;
+	int reg;
+
+	CPRINTS("%s %d: disable low power mode", CHARGER_NAME, chgnum);
+	rv = main_read8(chgnum, SM5803_REG_REFERENCE, &reg);
+	if (rv) {
+		CPRINTS("%s %d: Failed to read REFERENCE reg", CHARGER_NAME,
+			chgnum);
+		return;
+	}
+	/* Enable Psys DAC */
+	rv |= meas_read8(chgnum, SM5803_REG_PSYS1, &reg);
+	reg |= SM5803_PSYS1_DAC_EN;
+	rv |= meas_write8(chgnum, SM5803_REG_PSYS1, reg);
+
+	/* Enable PROCHOT comparators except Ibus */
+	rv |= chg_read8(chgnum, SM5803_REG_PHOT1, &reg);
+	reg |= SM5803_PHOT1_COMPARATOR_EN;
+	reg &= ~SM5803_PHOT1_IBUS_PHOT_COMP_EN;
+	rv |= chg_write8(chgnum, SM5803_REG_PHOT1, reg);
+
+	if (rv)
+		CPRINTS("%s %d: Failed to set in disable low power mode",
+			CHARGER_NAME, chgnum);
+}
+
+void sm5803_enable_low_power_mode(int chgnum)
+{
+	enum ec_error_list rv;
+	int reg;
+
+	CPRINTS("%s %d: enable low power mode", CHARGER_NAME, chgnum);
+	rv = main_read8(chgnum, SM5803_REG_REFERENCE, &reg);
+	if (rv) {
+		CPRINTS("%s %d: Failed to read REFERENCE reg", CHARGER_NAME,
+			chgnum);
+		return;
+	}
+	/* Disable Psys DAC */
+	rv |= meas_read8(chgnum, SM5803_REG_PSYS1, &reg);
+	reg &= ~SM5803_PSYS1_DAC_EN;
+	rv |= meas_write8(chgnum, SM5803_REG_PSYS1, reg);
+
+	/* Disable PROCHOT comparators */
+	rv |= chg_read8(chgnum, SM5803_REG_PHOT1, &reg);
+	reg &= ~SM5803_PHOT1_COMPARATOR_EN;
+	rv |= chg_write8(chgnum, SM5803_REG_PHOT1, reg);
+
+	if (rv)
+		CPRINTS("%s %d: Failed to set in enable low power mode",
+			CHARGER_NAME, chgnum);
+}
+
 /*
  * Process interrupt registers and report any Vbus changes.  Alert the AP if the
  * charger has become too hot.
diff --git a/driver/charger/sm5803.h b/driver/charger/sm5803.h
index fe71314b1a..93cf9a462d 100644
--- a/driver/charger/sm5803.h
+++ b/driver/charger/sm5803.h
@@ -335,6 +335,10 @@ enum ec_error_list sm5803_vbus_sink_enable(int chgnum, int enable);
 void sm5803_hibernate(int chgnum);
 void sm5803_interrupt(int chgnum);
 
+/* Expose low power mode functions */
+void sm5803_disable_low_power_mode(int chgnum);
+void sm5803_enable_low_power_mode(int chgnum);
+
 extern const struct charger_drv sm5803_drv;
 
 #endif