charge_state_v2: fix battfake command race condition

This moves battfake console command to the battery driver.
This fixes a race condition with using the 'battfake' command
where charge_state_v2 could return the real battery percentage
even when a faked percentage is specified, if a higher priority
task uses the battery state of charge in between when the
battery is read, and when the fake state of charge overwrites
the battery parameter.

BUG=chrome-os-partner:45878
BRANCH=none
TEST=use tap for battery with a faked state of charge. the tap
for battery queries the battery percentage a lot, so without
this CL, the tap sequence often temporarily jumps to different
percentages and colors. with this CL, the tap sequence works
great.

Change-Id: I3ae0866d1ff7bb8d0c51355cd6b958310766f19e
Signed-off-by: Alec Berg <alecaberg@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/302711
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>

3 files changed, 64 insertions, 33 deletions

diff --git a/common/charge_state_v2.c b/common/charge_state_v2.c
index 630ee06d74..0d89d470ce 100644
--- a/common/charge_state_v2.c
+++ b/common/charge_state_v2.c
@@ -62,7 +62,6 @@ static int battery_was_removed;
 
 static int problems_exist;
 static int debugging;
-static int fake_state_of_charge = -1;
 
 
 /* Track problems in communicating with the battery or charger */
@@ -618,12 +617,6 @@ void charger_task(void)
 
 		curr.chg.flags |= CHG_FLAG_INITIALIZED;
 
-		/* Fake state of charge if necessary */
-		if (fake_state_of_charge >= 0) {
-			curr.batt.state_of_charge = fake_state_of_charge;
-			curr.batt.flags &= ~BATT_FLAG_BAD_STATE_OF_CHARGE;
-		}
-
 		/*
 		 * TODO(crosbug.com/p/27527). Sometimes the battery thinks its
 		 * temperature is 6280C, which seems a bit high. Let's ignore
@@ -1167,30 +1160,6 @@ DECLARE_HOST_COMMAND(EC_CMD_CHARGE_STATE, charge_command_charge_state,
 /*****************************************************************************/
 /* Console commands */
 
-static int command_battfake(int argc, char **argv)
-{
-	char *e;
-	int v;
-
-	if (argc == 2) {
-		v = strtoi(argv[1], &e, 0);
-		if (*e || v < -1 || v > 100)
-			return EC_ERROR_PARAM1;
-
-		fake_state_of_charge = v;
-	}
-
-	if (fake_state_of_charge >= 0)
-		ccprintf("Fake batt %d%%\n",
-			 fake_state_of_charge);
-
-	return EC_SUCCESS;
-}
-DECLARE_CONSOLE_COMMAND(battfake, command_battfake,
-			"percent (-1 = use real level)",
-			"Set fake battery level",
-			NULL);
-
 static int command_chgstate(int argc, char **argv)
 {
 	int rv;
diff --git a/driver/battery/bq27541.c b/driver/battery/bq27541.c
index 2f7e1b2678..ae9f024cc2 100644
--- a/driver/battery/bq27541.c
+++ b/driver/battery/bq27541.c
@@ -46,6 +46,7 @@
 #define REG_PROTECTOR               0x6d
 
 static int battery_type_id;
+static int fake_state_of_charge = -1;
 
 static int bq27541_read(int offset, int *data)
 {
@@ -236,9 +237,12 @@ void battery_get_params(struct batt_params *batt)
 	if (bq27541_read(REG_TEMPERATURE, &batt->temperature))
 		batt->flags |= BATT_FLAG_BAD_TEMPERATURE;
 
-	if (bq27541_read8(REG_STATE_OF_CHARGE, &batt->state_of_charge))
+	if (bq27541_read8(REG_STATE_OF_CHARGE, &v) && fake_state_of_charge < 0)
 		batt->flags |= BATT_FLAG_BAD_STATE_OF_CHARGE;
 
+	batt->state_of_charge = fake_state_of_charge >= 0 ?
+					fake_state_of_charge : v;
+
 	if (bq27541_read(REG_VOLTAGE, &batt->voltage))
 		batt->flags |= BATT_FLAG_BAD_VOLTAGE;
 
@@ -327,3 +331,28 @@ enum battery_disconnect_state battery_get_disconnect_state(void)
 	return BATTERY_NOT_DISCONNECTED;
 }
 #endif /* CONFIG_BATTERY_REVIVE_DISCONNECT */
+
+static int command_battfake(int argc, char **argv)
+{
+	char *e;
+	int v;
+
+	if (argc == 2) {
+		v = strtoi(argv[1], &e, 0);
+		if (*e || v < -1 || v > 100)
+			return EC_ERROR_PARAM1;
+
+		fake_state_of_charge = v;
+	}
+
+	if (fake_state_of_charge >= 0)
+		ccprintf("Fake batt %d%%\n",
+			 fake_state_of_charge);
+
+	return EC_SUCCESS;
+}
+DECLARE_CONSOLE_COMMAND(battfake, command_battfake,
+			"percent (-1 = use real level)",
+			"Set fake battery level",
+			NULL);
+
diff --git a/driver/battery/smart.c b/driver/battery/smart.c
index 0c63e0fec1..112af6abb0 100644
--- a/driver/battery/smart.c
+++ b/driver/battery/smart.c
@@ -21,6 +21,8 @@
 #define BATTERY_WAIT_TIMEOUT		(2800*MSEC)
 #define BATTERY_NO_RESPONSE_TIMEOUT	(1000*MSEC)
 
+static int fake_state_of_charge = -1;
+
 test_mockable int sbc_read(int cmd, int *param)
 {
 	return i2c_read16(I2C_PORT_CHARGER, CHARGER_ADDR, cmd, param);
@@ -272,9 +274,14 @@ void battery_get_params(struct batt_params *batt)
 	if (sb_read(SB_TEMPERATURE, &batt_new.temperature))
 		batt_new.flags |= BATT_FLAG_BAD_TEMPERATURE;
 
-	if (sb_read(SB_RELATIVE_STATE_OF_CHARGE, &batt_new.state_of_charge))
+	if (sb_read(SB_RELATIVE_STATE_OF_CHARGE, &batt_new.state_of_charge)
+	    && fake_state_of_charge < 0)
 		batt_new.flags |= BATT_FLAG_BAD_STATE_OF_CHARGE;
 
+	/* If soc is faked, override with faked data */
+	if (fake_state_of_charge >= 0)
+		batt_new.state_of_charge = fake_state_of_charge;
+
 	if (sb_read(SB_VOLTAGE, &batt_new.voltage))
 		batt_new.flags |= BATT_FLAG_BAD_VOLTAGE;
 
@@ -378,6 +385,32 @@ int battery_wait_for_stable(void)
 	return EC_ERROR_TIMEOUT;
 }
 
+#ifndef CONFIG_CHARGER_V1
+static int command_battfake(int argc, char **argv)
+{
+	char *e;
+	int v;
+
+	if (argc == 2) {
+		v = strtoi(argv[1], &e, 0);
+		if (*e || v < -1 || v > 100)
+			return EC_ERROR_PARAM1;
+
+		fake_state_of_charge = v;
+	}
+
+	if (fake_state_of_charge >= 0)
+		ccprintf("Fake batt %d%%\n",
+			 fake_state_of_charge);
+
+	return EC_SUCCESS;
+}
+DECLARE_CONSOLE_COMMAND(battfake, command_battfake,
+			"percent (-1 = use real level)",
+			"Set fake battery level",
+			NULL);
+#endif
+
 /*****************************************************************************/
 /* Smart battery pass-through
  */