chgmgr: Allow charge_manager_update_charge to accept NULL

Currently, charge_manager_update_charge does not handle NULL pointer
for struct charge_port_info any differently. It's not sanity-checked
either (thus memory access violation can occur).

This patch will make charge_manager_update_charge accept NULL pointer
and set available current and voltage to zero.

This also helps callers' intentions be clear because callers can
explicitly specify NULL (instead of passing a pointer to chg = {0},
which is initialized somewhere else).

Signed-off-by: Daisuke Nojiri <dnojiri@chromium.org>

BUG=none
BRANCH=none
TEST=buildall

Change-Id: I518662ab6a3a07f93da5d34cf62a6f856884f67d
Reviewed-on: https://chromium-review.googlesource.com/1226125
Commit-Ready: Daisuke Nojiri <dnojiri@chromium.org>
Tested-by: Daisuke Nojiri <dnojiri@chromium.org>
Reviewed-by: Daisuke Nojiri <dnojiri@chromium.org>

4 files changed, 23 insertions, 39 deletions

diff --git a/driver/bc12/bq24392.c b/driver/bc12/bq24392.c
index 3092f9f794..b74781f221 100644
--- a/driver/bc12/bq24392.c
+++ b/driver/bc12/bq24392.c
@@ -107,13 +107,12 @@ static void bc12_detect(const int port)
 static void power_down_ic(const int port)
 {
 	const struct bq24392_config_t * const cfg = &bq24392_config[port];
-	struct charge_port_info no_chg = { 0 };
 
 	/* Turn off the IC. */
 	activate_chip_enable(cfg, 0);
 
 	/* Let charge manager know there's no more charge available. */
-	charge_manager_update_charge(CHARGE_SUPPLIER_OTHER, port, &no_chg);
+	charge_manager_update_charge(CHARGE_SUPPLIER_OTHER, port, NULL);
 }
 
 /**
diff --git a/driver/bc12/pi3usb9281.c b/driver/bc12/pi3usb9281.c
index 9bdf875468..f1bd3ce8d4 100644
--- a/driver/bc12/pi3usb9281.c
+++ b/driver/bc12/pi3usb9281.c
@@ -289,7 +289,6 @@ void usb_charger_set_switches(int port, enum usb_switch setting)
 static void bc12_detect(int port)
 {
 	int device_type, charger_status;
-	struct charge_port_info charge = {0};
 	int type;
 
 	if (usb_charger_port_is_sourcing_vbus(port)) {
@@ -351,6 +350,7 @@ static void bc12_detect(int port)
 
 	/* Attachment: decode + update available charge */
 	if (device_type || PI3USB9281_CHG_STATUS_ANY(charger_status)) {
+		struct charge_port_info chg;
 		if (PI3USB9281_CHG_STATUS_ANY(charger_status))
 			type = CHARGE_SUPPLIER_PROPRIETARY;
 		else if (device_type & PI3USB9281_TYPE_CDP)
@@ -362,31 +362,21 @@ static void bc12_detect(int port)
 		else
 			type = CHARGE_SUPPLIER_OTHER;
 
-		charge.voltage = USB_CHARGER_VOLTAGE_MV;
-		charge.current = pi3usb9281_get_ilim(device_type,
-						     charger_status);
-		charge_manager_update_charge(type, port, &charge);
-	} else { /* Detachment */
-		charge_manager_update_charge(
-					CHARGE_SUPPLIER_PROPRIETARY,
-					port,
-					&charge);
-		charge_manager_update_charge(
-					CHARGE_SUPPLIER_BC12_CDP,
-					port,
-					&charge);
-		charge_manager_update_charge(
-					CHARGE_SUPPLIER_BC12_DCP,
-					port,
-					&charge);
-		charge_manager_update_charge(
-					CHARGE_SUPPLIER_BC12_SDP,
-					port,
-					&charge);
-		charge_manager_update_charge(
-					CHARGE_SUPPLIER_OTHER,
-					port,
-					&charge);
+		chg.voltage = USB_CHARGER_VOLTAGE_MV;
+		chg.current = pi3usb9281_get_ilim(device_type, charger_status);
+		charge_manager_update_charge(type, port, &chg);
+	} else {
+		/* Detachment */
+		charge_manager_update_charge(CHARGE_SUPPLIER_PROPRIETARY,
+					     port, NULL);
+		charge_manager_update_charge(CHARGE_SUPPLIER_BC12_CDP,
+					     port, NULL);
+		charge_manager_update_charge(CHARGE_SUPPLIER_BC12_DCP,
+					     port, NULL);
+		charge_manager_update_charge(CHARGE_SUPPLIER_BC12_SDP,
+					     port, NULL);
+		charge_manager_update_charge(CHARGE_SUPPLIER_OTHER,
+					     port, NULL);
 	}
 }
 
diff --git a/driver/charger/bd9995x.c b/driver/charger/bd9995x.c
index 5423099e52..9ab69a7c38 100644
--- a/driver/charger/bd9995x.c
+++ b/driver/charger/bd9995x.c
@@ -438,10 +438,8 @@ static int bd9995x_bc12_check_type(int port)
 
 static void bd9995x_bc12_detach(int port, int type)
 {
-	struct charge_port_info charge = {0};
-
 	/* Update charge manager */
-	charge_manager_update_charge(type, port, &charge);
+	charge_manager_update_charge(type, port, NULL);
 
 	/* Disable charging trigger by BC1.2 detection */
 	bd9995x_bc12_enable_charging(port, 0);
diff --git a/driver/charger/rt946x.c b/driver/charger/rt946x.c
index 757d5a3c0d..9bb1a6cfd7 100644
--- a/driver/charger/rt946x.c
+++ b/driver/charger/rt946x.c
@@ -903,10 +903,11 @@ void rt946x_interrupt(enum gpio_signal signal)
 
 void usb_charger_task(void *u)
 {
-	struct charge_port_info charge;
+	struct charge_port_info chg;
 	int bc12_type = CHARGE_SUPPLIER_NONE;
 	int reg = 0;
 
+	chg.voltage = USB_CHARGER_VOLTAGE_MV;
 	while (1) {
 		rt946x_read8(RT946X_REG_DPDMIRQ, &reg);
 
@@ -914,20 +915,16 @@ void usb_charger_task(void *u)
 		if (reg & RT946X_MASK_DPDMIRQ_ATTACH) {
 			bc12_type = rt946x_get_bc12_device_type();
 			if (bc12_type != CHARGE_SUPPLIER_NONE) {
-				charge.voltage = USB_CHARGER_VOLTAGE_MV;
-				charge.current =
-					rt946x_get_bc12_ilim(bc12_type);
+				chg.current = rt946x_get_bc12_ilim(bc12_type);
 				charge_manager_update_charge(bc12_type,
-							     0, &charge);
+							     0, &chg);
 				rt946x_enable_bc12_detection(0);
 			}
 		}
 
 		/* VBUS detach event */
 		if (reg & RT946X_MASK_DPDMIRQ_DETACH) {
-			charge.current = 0;
-			charge.voltage = 0;
-			charge_manager_update_charge(bc12_type, 0, &charge);
+			charge_manager_update_charge(bc12_type, 0, NULL);
 			rt946x_enable_bc12_detection(1);
 		}