SM5803: Enable hibernate function for z-state

Enable SM5803 hibernation and restore registers after booting back from
z-state.

BRANCH=None
BUG=b:166648029
TEST=on drawlat, z-state power usage is reduced and booting after
z-state the charger chips can sink and source as expected

Signed-off-by: Diana Z <dzigterman@chromium.org>
Change-Id: I6e9f9f29a184fa6177e589b3b7810f51a1b3345b
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2393225
Reviewed-by: Aseda Aboagye <aaboagye@chromium.org>
Commit-Queue: Aseda Aboagye <aaboagye@chromium.org>

1 files changed, 72 insertions, 2 deletions

diff --git a/driver/charger/sm5803.c b/driver/charger/sm5803.c
index 85bd9ce081..30f9826ff6 100644
--- a/driver/charger/sm5803.c
+++ b/driver/charger/sm5803.c
@@ -527,8 +527,32 @@ static void sm5803_init(int chgnum)
 		rv |= main_write8(chgnum, 0x1F, 0x0);
 	}
 
-	/* Disable Ibus PROCHOT comparator */
-	rv = chg_read8(chgnum, SM5803_REG_PHOT1, &reg);
+	/* Enable LDO bits */
+	rv |= main_read8(chgnum, SM5803_REG_REFERENCE, &reg);
+	reg &= ~(BIT(0) | BIT(1));
+	rv |= main_write8(chgnum, SM5803_REG_REFERENCE, reg);
+
+	/* Set a higher clock speed in case it was lowered for z-state */
+	rv |= main_read8(chgnum, SM5803_REG_CLOCK_SEL, &reg);
+	reg &= ~SM5803_CLOCK_SEL_LOW;
+	rv |= main_write8(chgnum, SM5803_REG_CLOCK_SEL, reg);
+
+	/* Turn on GPADCs to default */
+	rv |= meas_write8(chgnum, SM5803_REG_GPADC_CONFIG1, 0xF3);
+
+	/* 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 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);
+
+	/* 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);
 
@@ -632,6 +656,52 @@ static enum ec_error_list sm5803_post_init(int chgnum)
 	return EC_SUCCESS;
 }
 
+void sm5803_hibernate(int chgnum)
+{
+	enum ec_error_list rv;
+	int reg;
+
+	rv = main_read8(chgnum, SM5803_REG_REFERENCE, &reg);
+	if (rv) {
+		CPRINTS("%s %d: Failed to read REFERENCE reg", CHARGER_NAME,
+			chgnum);
+		return;
+	}
+
+	/* Disable LDO bits - note the primary LDO should not be disabled */
+	if (chgnum != CHARGER_PRIMARY) {
+		reg |= (BIT(0) | BIT(1));
+		rv |= main_write8(chgnum, SM5803_REG_REFERENCE, reg);
+	}
+
+	/* 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);
+
+	/* Turn off GPADCs */
+	rv |= meas_write8(chgnum, SM5803_REG_GPADC_CONFIG1, 0);
+	rv |= meas_write8(chgnum, SM5803_REG_GPADC_CONFIG2, 0);
+
+	/* 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 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);
+
+	/* 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 hibernate", CHARGER_NAME, chgnum);
+}
+
 /*
  * Process interrupt registers and report any Vbus changes.  Alert the AP if the
  * charger has become too hot.