kukui: Fix shipping mode VSYS leakage.

Follow the cut-off procedure recommended by Richtek.

Also, tcpc_read/tcpc_write function will wake the TCPC up from low power
mode and thus causing the TCPC re-init again, and this will break the
register state we set. So, here we use mt6370_i2c_read/write to replace
tcpc_read/write.

TEST=boot system; Exec cutoff, and check that Vsys equals to zero.
BUG=b:116682788
BRANCH=None

Change-Id: I5cbd0df490ddb64b9376507e42a259c008c3ba16
Signed-off-by: Yilun Lin <yllin@google.com>
Reviewed-on: https://chromium-review.googlesource.com/1335289
Commit-Ready: Yilun Lin <yllin@chromium.org>
Tested-by: Yilun Lin <yllin@chromium.org>
Reviewed-by: Nicolas Boichat <drinkcat@chromium.org>

5 files changed, 96 insertions, 5 deletions

diff --git a/board/kukui/battery.c b/board/kukui/battery.c
index 0c875d0032..ff5764ff97 100644
--- a/board/kukui/battery.c
+++ b/board/kukui/battery.c
@@ -11,6 +11,7 @@
 #include "console.h"
 #include "driver/battery/max17055.h"
 #include "driver/charger/rt946x.h"
+#include "driver/tcpm/mt6370.h"
 #include "ec_commands.h"
 #include "extpower.h"
 #include "gpio.h"
@@ -82,7 +83,12 @@ const struct max17055_alert_profile *max17055_get_alert_profile(void)
 
 int board_cut_off_battery(void)
 {
-	return rt946x_cutoff_battery();
+	/* The cut-off procedure is recommended by Richtek. b/116682788 */
+	rt946x_por_reset();
+	mt6370_vconn_discharge(0);
+	rt946x_cutoff_battery();
+
+	return EC_SUCCESS;
 }
 
 enum battery_disconnect_state battery_get_disconnect_state(void)
diff --git a/driver/charger/rt946x.c b/driver/charger/rt946x.c
index 9bb1a6cfd7..c6f748017d 100644
--- a/driver/charger/rt946x.c
+++ b/driver/charger/rt946x.c
@@ -213,15 +213,28 @@ static inline int rt946x_enable_hz(int en)
 		(RT946X_REG_CHGCTRL1, RT946X_MASK_HZ_EN);
 }
 
-static int rt946x_por_reset(void)
+int rt946x_por_reset(void)
 {
-	int rv = 0;
+	int rv, val;
 
+#ifdef CONFIG_CHARGER_MT6370
+	/* Soft reset. It takes only 1ns for resetting. b/116682788 */
+	val = RT946X_MASK_SOFT_RST;
+	/*
+	 * MT6370 has to set passcodes before resetting all the registers and
+	 * logics.
+	 */
+	rv = rt946x_write8(MT6370_REG_RSTPASCODE1, MT6370_MASK_RSTPASCODE1);
+	rv |= rt946x_write8(MT6370_REG_RSTPASCODE2, MT6370_MASK_RSTPASCODE2);
+#else
+	/* Hard reset, may take several milliseconds. */
+	val = RT946X_MASK_RST;
 	rv = rt946x_enable_hz(0);
+#endif
 	if (rv)
 		return rv;
 
-	return rt946x_set_bit(RT946X_REG_CORECTRL_RST, RT946X_MASK_RST);
+	return rt946x_set_bit(RT946X_REG_CORECTRL_RST, val);
 }
 
 static int rt946x_reset_to_zero(void)
@@ -967,7 +980,12 @@ int rt946x_is_charge_done(void)
 
 int rt946x_cutoff_battery(void)
 {
-	return rt946x_set_bit(RT946X_REG_CHGCTRL2, RT946X_MASK_SHIP_MODE);
+	int val = RT946X_MASK_SHIP_MODE;
+
+#ifdef CONFIG_CHARGER_MT6370
+	val |= RT946X_MASK_TE | RT946X_MASK_CFO_EN | RT946X_MASK_CHG_EN;
+#endif
+	return rt946x_set_bit(RT946X_REG_CHGCTRL2, val);
 }
 
 int rt946x_enable_charge_termination(int en)
diff --git a/driver/charger/rt946x.h b/driver/charger/rt946x.h
index ff126bc079..21ce65536b 100644
--- a/driver/charger/rt946x.h
+++ b/driver/charger/rt946x.h
@@ -92,6 +92,8 @@
 #define RT946X_REG_CORECTRL1		0x01
 #define RT946X_REG_CORECTRL2		0x02
 #define RT946X_REG_CORECTRL_RST		RT946X_REG_CORECTRL2
+#define MT6370_REG_RSTPASCODE1		0x03
+#define MT6370_REG_RSTPASCODE2		0x04
 #define RT946X_REG_CHGCTRL1		0x11
 #define RT946X_REG_CHGCTRL2		0x12
 #define RT946X_REG_CHGCTRL3		0x13
@@ -229,8 +231,26 @@
 
 /* ========== CORECTRL0 0x00 ============ */
 #define RT946X_SHIFT_RST	7
+#define RT946X_SHIFT_CHG_RST	6
+#define RT946X_SHIFT_FLED_RST	5
+#define RT946X_SHIFT_LDO_RST	4
+#define RT946X_SHIFT_RGB_RST	3
+#define RT946X_SHIFT_BL_RST	2
+#define RT946X_SHIFT_DB_RST	1
+#define RT946X_SHIFT_REG_RST	0
 
 #define RT946X_MASK_RST		(1 << RT946X_SHIFT_RST)
+#define RT946X_MASK_CHG_RST	(1 << RT946X_SHIFT_CHG_RST)
+#define RT946X_MASK_FLED_RST	(1 << RT946X_SHIFT_FLED_RST)
+#define RT946X_MASK_LDO_RST	(1 << RT946X_SHIFT_LDO_RST)
+#define RT946X_MASK_RGB_RST	(1 << RT946X_SHIFT_RGB_RST)
+#define RT946X_MASK_BL_RST	(1 << RT946X_SHIFT_BL_RST)
+#define RT946X_MASK_DB_RST	(1 << RT946X_SHIFT_DB_RST)
+#define RT946X_MASK_REG_RST	(1 << RT946X_SHIFT_REG_RST)
+#define RT946X_MASK_SOFT_RST                                                   \
+	(RT946X_MASK_CHG_RST | RT946X_MASK_FLED_RST | RT946X_MASK_LDO_RST |    \
+	 RT946X_MASK_RGB_RST | RT946X_MASK_BL_RST | RT946X_MASK_DB_RST |       \
+	 RT946X_MASK_REG_RST)
 
 /* ========== CHGCTRL1 0x01 ============ */
 #define RT946X_SHIFT_OPA_MODE   0
@@ -243,13 +263,18 @@
 #define RT946X_SHIFT_SHIP_MODE	7
 #define RT946X_SHIFT_TE		4
 #define RT946X_SHIFT_ILMTSEL	2
+#define RT946X_SHIFT_CFO_EN	1
 #define RT946X_SHIFT_CHG_EN	0
 
 #define RT946X_MASK_SHIP_MODE	(1 << RT946X_SHIFT_SHIP_MODE)
 #define RT946X_MASK_TE		(1 << RT946X_SHIFT_TE)
 #define RT946X_MASK_ILMTSEL	(0x3 << RT946X_SHIFT_ILMTSEL)
+#define RT946X_MASK_CFO_EN	(1 << RT946X_SHIFT_CFO_EN)
 #define RT946X_MASK_CHG_EN	(1 << RT946X_SHIFT_CHG_EN)
 
+/* ========== RSTPASCODE1 0x03 (mt6370) ============ */
+#define MT6370_MASK_RSTPASCODE1	0xA9
+
 /* ========== CHGCTRL3 0x03 ============ */
 #define RT946X_SHIFT_AICR	2
 #define RT946X_SHIFT_ILIMEN	0
@@ -257,6 +282,9 @@
 #define RT946X_MASK_AICR	(0x3F << RT946X_SHIFT_AICR)
 #define RT946X_MASK_ILIMEN	(1 << RT946X_SHIFT_ILIMEN)
 
+/* ========== RSTPASCODE2 0x04 (mt6370) ============ */
+#define MT6370_MASK_RSTPASCODE2	0x96
+
 /* ========== CHGCTRL4 0x04 ============ */
 #define RT946X_SHIFT_CV	1
 
@@ -475,6 +503,9 @@
 
 /* RT946x specific interface functions */
 
+/* Power on reset */
+int rt946x_por_reset(void);
+
 /* Interrupt handler for rt946x */
 void rt946x_interrupt(enum gpio_signal signal);
 
diff --git a/driver/tcpm/mt6370.c b/driver/tcpm/mt6370.c
index a77dd96b57..dba3a045a0 100644
--- a/driver/tcpm/mt6370.c
+++ b/driver/tcpm/mt6370.c
@@ -19,6 +19,13 @@
 #define CPRINTS(format, args...) cprints(CC_USBCHARGE, format, ## args)
 #define CPRINTF(format, args...) cprintf(CC_USBCHARGE, format, ## args)
 
+/* i2c_write function which won't wake TCPC from low power mode. */
+static int mt6370_i2c_write8(int port, int reg, int val)
+{
+	return i2c_write8(tcpc_config[port].i2c_host_port,
+			  tcpc_config[port].i2c_slave_addr, reg, val);
+}
+
 static int mt6370_init(int port)
 {
 	int rv;
@@ -118,6 +125,22 @@ static int mt6370_enter_low_power_mode(int port)
 }
 #endif
 
+int mt6370_vconn_discharge(int port)
+{
+	/*
+	 * Write to mt6370 in low-power mode may return fail, but it is
+	 * actually written. So we just ignore its return value.
+	 */
+	mt6370_i2c_write8(port, MT6370_REG_OVP_FLAG_SEL,
+			  MT6370_REG_DISCHARGE_LVL);
+	/* Set MT6370_REG_DISCHARGE_EN bit and also the rest default value. */
+	mt6370_i2c_write8(port, MT6370_REG_BMC_CTRL,
+			  MT6370_REG_DISCHARGE_EN |
+				  MT6370_REG_BMC_CTRL_DEFAULT);
+
+	return EC_SUCCESS;
+}
+
 /* MT6370 is a TCPCI compatible port controller */
 const struct tcpm_drv mt6370_tcpm_drv = {
 	.init			= &mt6370_init,
diff --git a/driver/tcpm/mt6370.h b/driver/tcpm/mt6370.h
index ff9ac569ee..5fdcffbdca 100644
--- a/driver/tcpm/mt6370.h
+++ b/driver/tcpm/mt6370.h
@@ -102,6 +102,16 @@
 #define MT6370_REG_BMCIO_BG_EN			(1 << 2)
 #define MT6370_REG_VBUS_DET_EN			(1 << 1)
 #define MT6370_REG_BMCIO_OSC_EN			(1 << 0)
+#define MT6370_REG_BMC_CTRL_DEFAULT                                            \
+	(MT6370_REG_BMCIO_BG_EN | MT6370_REG_VBUS_DET_EN |                     \
+	 MT6370_REG_BMCIO_OSC_EN)
+
+/*
+ * MT6370_REG_OVP_FLAG_SEL
+ */
+
+#define MT6370_MASK_DISCHARGE_LVL		0x03
+#define MT6370_REG_DISCHARGE_LVL		(1 << 0)
 
 /*
  * MT6370_REG_RT_STATUS				0x97
@@ -176,4 +186,7 @@
 
 extern const struct tcpm_drv mt6370_tcpm_drv;
 
+/* Enable VCONN discharge. */
+int mt6370_vconn_discharge(int port);
+
 #endif /* __CROS_EC_USB_PD_TCPM_MT6370_H */