SM5803: Configure lower TINT threshold

In order to detect when temperatures have returned to a good range and
cease AP throttling, add the lower TINT threshold.

BUG=b:148289370
BRANCH=None
TEST=make -j buildall

Signed-off-by: Diana Z <dzigterman@chromium.org>
Change-Id: Id8a22c4220539e3959cd2f831552f57ab12853fd
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/2115569
Reviewed-by: Aseda Aboagye <aaboagye@chromium.org>

2 files changed, 30 insertions, 10 deletions

diff --git a/driver/charger/sm5803.c b/driver/charger/sm5803.c
index 6f5f409406..75bc48fff5 100644
--- a/driver/charger/sm5803.c
+++ b/driver/charger/sm5803.c
@@ -186,8 +186,11 @@ static void sm5803_init(int chgnum)
 	rv |= meas_write8(chgnum, SM5803_REG_VBUS_HIGH_TH,
 			  SM5803_VBUS_HIGH_LEVEL);
 
-	/* Set TINT for 360K (steps are in 0.43K) */
-	rv |= meas_write8(chgnum, SM5803_REG_TINT_HIGH_TH, 0xD1);
+	/* Set TINT interrupts for 360 K and 330 K */
+	rv |= meas_write8(chgnum, SM5803_REG_TINT_HIGH_TH,
+						SM5803_TINT_HIGH_LEVEL);
+	rv |= meas_write8(chgnum, SM5803_REG_TINT_LOW_TH,
+						SM5803_TINT_LOW_LEVEL);
 
 	if (rv)
 		CPRINTS("%s %d: Failed initialization", CHARGER_NAME, chgnum);
@@ -206,7 +209,7 @@ static enum ec_error_list sm5803_post_init(int chgnum)
 void sm5803_handle_interrupt(int chgnum)
 {
 	enum ec_error_list rv;
-	int int_reg, vbus_reg;
+	int int_reg, meas_reg;
 
 	/* Note: Interrupt register is clear on read */
 	rv = main_read8(chgnum, SM5803_REG_INT2_REQ, &int_reg);
@@ -217,21 +220,28 @@ void sm5803_handle_interrupt(int chgnum)
 	}
 
 	if (int_reg & SM5803_INT2_TINT) {
-		CPRINTS("%s %d: High temp, throttling AP", CHARGER_NAME,
-			chgnum);
-		throttle_ap(THROTTLE_ON, THROTTLE_HARD, THROTTLE_SRC_THERMAL);
+		rv = meas_read8(chgnum, SM5803_REG_TINT_MEAS_MSB, &meas_reg);
+		if (meas_reg <= SM5803_TINT_LOW_LEVEL)
+			throttle_ap(THROTTLE_OFF, THROTTLE_HARD,
+							THROTTLE_SRC_THERMAL);
+		else if (meas_reg >= SM5803_TINT_HIGH_LEVEL)
+			throttle_ap(THROTTLE_ON, THROTTLE_HARD,
+							THROTTLE_SRC_THERMAL);
+		else
+			CPRINTS("%s %d: Unexpected TINT interrupt: 0x%02x",
+				CHARGER_NAME, chgnum, meas_reg);
 	}
 
 	if ((int_reg & SM5803_INT2_VBUS) &&
 				!sm5803_is_sourcing_otg_power(chgnum, chgnum)) {
-		rv = meas_read8(chgnum, SM5803_REG_VBUS_MEAS_MSB, &vbus_reg);
-		if (vbus_reg <= SM5803_VBUS_LOW_LEVEL)
+		rv = meas_read8(chgnum, SM5803_REG_VBUS_MEAS_MSB, &meas_reg);
+		if (meas_reg <= SM5803_VBUS_LOW_LEVEL)
 			usb_charger_vbus_change(chgnum, 0);
-		else if (vbus_reg >= SM5803_VBUS_HIGH_LEVEL)
+		else if (meas_reg >= SM5803_VBUS_HIGH_LEVEL)
 			usb_charger_vbus_change(chgnum, 1);
 		else
 			CPRINTS("%s %d: Unexpected Vbus interrupt: 0x%02x",
-				CHARGER_NAME, chgnum, vbus_reg);
+				CHARGER_NAME, chgnum, meas_reg);
 	}
 }
 
diff --git a/driver/charger/sm5803.h b/driver/charger/sm5803.h
index 8b96ac8f94..09a47b423e 100644
--- a/driver/charger/sm5803.h
+++ b/driver/charger/sm5803.h
@@ -111,6 +111,7 @@ enum sm5803_gpio0_modes {
 /* Note: Threshold registers all assume lower 2 bits are 0 */
 #define SM5803_REG_VBUS_LOW_TH		0x1B
 #define SM5803_REG_VBUS_HIGH_TH		0x2B
+#define SM5803_REG_TINT_LOW_TH		0x1D
 #define SM5803_REG_TINT_HIGH_TH		0x2D
 
 /*
@@ -120,6 +121,13 @@ enum sm5803_gpio0_modes {
 #define SM5803_VBUS_LOW_LEVEL		0x25
 #define SM5803_VBUS_HIGH_LEVEL		0x2C
 
+/*
+ * TINT thresholds.  TINT steps are in 0.43 K with the upper threshold set to
+ * 360 K and lower threshold to de-assert PROCHOT at 330 K.
+ */
+#define SM5803_TINT_LOW_LEVEL		0xBF
+#define SM5803_TINT_HIGH_LEVEL		0xD1
+
 #define SM5803_REG_VBUS_MEAS_MSB	0x48
 #define SM5803_REG_VBUS_MEAS_LSB	0x49
 #define SM5803_VBUS_MEAS_LSB		GENMASK(1, 0)
@@ -128,6 +136,8 @@ enum sm5803_gpio0_modes {
 #define SM5803_VBUS_MEAS_OV_TEMP	BIT(5)
 #define SM5803_VBUS_MEAS_CHG_DET	BIT(6)
 
+#define SM5803_REG_TINT_MEAS_MSB	0x4E
+
 /* Charger registers (address 0x32) */
 
 #define SM5803_REG_FLOW1		0x1C