spring: Do not charge when cutting off the battery

If a charger is plugged in while we are cutting off the battery, the EC
will be powered by external power, and the battery will be in a state
where it doesn't charge. Let's stop charging in this case to get the
battery into cut-off state properly and resume charging 5 seconds after.

BUG=chrome-os-partner:21107
TEST=Plug in the charger while cutting off the battery.
BRANCH=Spring

Change-Id: I5505485be7872f9887efc725a2b3aa610c6b42b9
Signed-off-by: Vic Yang <victoryang@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/63647
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>

5 files changed, 37 insertions, 3 deletions

diff --git a/board/spring/board.h b/board/spring/board.h
index 7f77d3268b..f82b0b8dc9 100644
--- a/board/spring/board.h
+++ b/board/spring/board.h
@@ -33,7 +33,7 @@
 
 /* Auto battery cut-off */
 #define BATTERY_CUT_OFF_MAH 10
-#define BATTERY_CUT_OFF_DELAY (11 * SECOND)
+#define BATTERY_CUT_OFF_DELAY (15 * SECOND)
 
 /* use STOP mode when we have nothing to do */
 #define CONFIG_LOW_POWER_IDLE
diff --git a/common/battery_spring.c b/common/battery_spring.c
index 840ed3fdfe..f86e91cd5d 100644
--- a/common/battery_spring.c
+++ b/common/battery_spring.c
@@ -26,6 +26,9 @@
 #define BATTERY_CUT_OFF_DELAY 0
 #endif
 
+static timestamp_t last_cutoff;
+static int has_cutoff;
+
 int battery_cut_off(void)
 {
 	int rv;
@@ -40,15 +43,26 @@ int battery_cut_off(void)
 	rv = i2c_xfer(I2C_PORT_BATTERY, BATTERY_ADDR, buf, 3, NULL, 0);
 	i2c_unlock();
 
+	has_cutoff = 1;
+	last_cutoff = get_time();
+
 	return rv;
 }
 
+int battery_is_cut_off(void)
+{
+	return has_cutoff &&
+	       get_time().val - last_cutoff.val < BATTERY_CUT_OFF_DELAY;
+}
+
 int battery_check_cut_off(void)
 {
 	int charge;
 
 	if (!BATTERY_CUT_OFF_MAH)
 		return 0;
+	if (battery_is_cut_off())
+		return 0;
 	if (chipset_in_state(CHIPSET_STATE_ON | CHIPSET_STATE_SUSPEND))
 		return 0;
 	if (battery_remaining_capacity(&charge))
diff --git a/common/pmu_tps65090_charger.c b/common/pmu_tps65090_charger.c
index 6f057fbe39..1f357ad946 100644
--- a/common/pmu_tps65090_charger.c
+++ b/common/pmu_tps65090_charger.c
@@ -206,6 +206,9 @@ static int calc_next_state(int state)
 			return ST_IDLE;
 		}
 
+		if (battery_is_cut_off())
+			return ST_BAD_COND;
+
 		/* Stay in idle mode if charger overtemp */
 		if (pmu_is_charger_alarm())
 			return ST_BAD_COND;
diff --git a/common/smart_battery_stub.c b/common/smart_battery_stub.c
index f00cc921a7..cca438fc6f 100644
--- a/common/smart_battery_stub.c
+++ b/common/smart_battery_stub.c
@@ -5,6 +5,8 @@
  * Functions needed by smart battery driver.
  */
 
+#include "battery_pack.h"
+#include "common.h"
 #include "smart_battery.h"
 #include "i2c.h"
 
@@ -15,7 +17,15 @@ int sbc_write(int cmd, int param)
 	{ return i2c_write16(I2C_PORT_CHARGER, CHARGER_ADDR, cmd, param); }
 
 int sb_read(int cmd, int *param)
-	{ return i2c_read16(I2C_PORT_BATTERY, BATTERY_ADDR, cmd, param); }
+{
+	if (battery_is_cut_off())
+		return EC_ERROR_INVAL;
+	return i2c_read16(I2C_PORT_BATTERY, BATTERY_ADDR, cmd, param);
+}
 
 int sb_write(int cmd, int param)
-	{ return i2c_write16(I2C_PORT_BATTERY, BATTERY_ADDR, cmd, param); }
+{
+	if (battery_is_cut_off())
+		return EC_ERROR_INVAL;
+	return i2c_write16(I2C_PORT_BATTERY, BATTERY_ADDR, cmd, param);
+}
diff --git a/include/battery_pack.h b/include/battery_pack.h
index 0a43619102..5e0593a75a 100644
--- a/include/battery_pack.h
+++ b/include/battery_pack.h
@@ -58,4 +58,11 @@ int battery_cut_off(void);
  */
 int battery_check_cut_off(void);
 
+/**
+ * Check if the battery is already cut off.
+ *
+ * @return 1 if battery has been cut off.
+ */
+int battery_is_cut_off(void);
+
 #endif