HID: wacom: Add ability to provide explicit battery status info

At the moment, our driver relies on 'wacom_battery_get_property()' to
determine the most likely battery state (e.g charging, discharging, or
full) based on the information available. It is not always possible
for the function to properly determine this, however. For instance,
whenever an AES pen leaves proximity the battery state becomes
indeterminite. This commit adds the ability to provide it with explict
state information if desired. Whenever explicit state is not required
(the majority of circumstances), WACOM_POWER_SUPPLY_STATUS_AUTO can
be used in its place.

Three uses of explicit battery status are added: two wireless disconnect
paths and the AES case mentioned above.
Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Reviewed-by: Ping Cheng <ping.cheng@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/wacom.h

@@ -138,6 +138,7 @@ struct wacom_battery {
 	struct power_supply_desc bat_desc;
 	struct power_supply *battery;
 	char bat_name[WACOM_NAME_MAX];
+	int bat_status;
 	int battery_capacity;
 	int bat_charging;
 	int bat_connected;

drivers/hid/wacom_sys.c

@@ -1547,7 +1547,9 @@ static int wacom_battery_get_property(struct power_supply *psy,
 			val->intval = battery->battery_capacity;
 			break;
 		case POWER_SUPPLY_PROP_STATUS:
-			if (battery->bat_charging)
+			if (battery->bat_status != WACOM_POWER_SUPPLY_STATUS_AUTO)
+				val->intval = battery->bat_status;
+			else if (battery->bat_charging)
 				val->intval = POWER_SUPPLY_STATUS_CHARGING;
 			else if (battery->battery_capacity == 100 &&
 				    battery->ps_connected)

drivers/hid/wacom_wac.c

@@ -57,15 +57,18 @@ static unsigned short batcap_gr[8] = { 1, 15, 25, 35, 50, 70, 100, 100 };
 static unsigned short batcap_i4[8] = { 1, 15, 30, 45, 60, 70, 85, 100 };
 
 static void __wacom_notify_battery(struct wacom_battery *battery,
-				   int bat_capacity, bool bat_charging,
-				   bool bat_connected, bool ps_connected)
+				   int bat_status, int bat_capacity,
+				   bool bat_charging, bool bat_connected,
+				   bool ps_connected)
 {
-	bool changed = battery->battery_capacity != bat_capacity  ||
+	bool changed = battery->bat_status       != bat_status    ||
+		       battery->battery_capacity != bat_capacity  ||
 		       battery->bat_charging     != bat_charging  ||
 		       battery->bat_connected    != bat_connected ||
 		       battery->ps_connected     != ps_connected;
 
 	if (changed) {
+		battery->bat_status = bat_status;
 		battery->battery_capacity = bat_capacity;
 		battery->bat_charging = bat_charging;
 		battery->bat_connected = bat_connected;
@@ -77,13 +80,13 @@ static void __wacom_notify_battery(struct wacom_battery *battery,
 }
 
 static void wacom_notify_battery(struct wacom_wac *wacom_wac,
-	int bat_capacity, bool bat_charging, bool bat_connected,
-	bool ps_connected)
+	int bat_status, int bat_capacity, bool bat_charging,
+	bool bat_connected, bool ps_connected)
 {
 	struct wacom *wacom = container_of(wacom_wac, struct wacom, wacom_wac);
 
-	__wacom_notify_battery(&wacom->battery, bat_capacity, bat_charging,
-			       bat_connected, ps_connected);
+	__wacom_notify_battery(&wacom->battery, bat_status, bat_capacity,
+			       bat_charging, bat_connected, ps_connected);
 }
 
 static int wacom_penpartner_irq(struct wacom_wac *wacom)
@@ -448,8 +451,9 @@ static int wacom_graphire_irq(struct wacom_wac *wacom)
 		rw = (data[7] >> 2 & 0x07);
 		battery_capacity = batcap_gr[rw];
 		ps_connected = rw == 7;
-		wacom_notify_battery(wacom, battery_capacity, ps_connected,
-				     1, ps_connected);
+		wacom_notify_battery(wacom, WACOM_POWER_SUPPLY_STATUS_AUTO,
+				     battery_capacity, ps_connected, 1,
+				     ps_connected);
 	}
 exit:
 	return retval;
@@ -1071,7 +1075,8 @@ static int wacom_remote_irq(struct wacom_wac *wacom_wac, size_t len)
 			wacom->led.groups[i].select = touch_ring_mode;
 	}
 
-	__wacom_notify_battery(&remote->remotes[index].battery, bat_percent,
+	__wacom_notify_battery(&remote->remotes[index].battery,
+				WACOM_POWER_SUPPLY_STATUS_AUTO, bat_percent,
 				bat_charging, 1, bat_charging);
 
 out:
@@ -1157,7 +1162,8 @@ static int wacom_intuos_bt_irq(struct wacom_wac *wacom, size_t len)
 		bat_charging = (power_raw & 0x08) ? 1 : 0;
 		ps_connected = (power_raw & 0x10) ? 1 : 0;
 		battery_capacity = batcap_i4[power_raw & 0x07];
-		wacom_notify_battery(wacom, battery_capacity, bat_charging,
+		wacom_notify_battery(wacom, WACOM_POWER_SUPPLY_STATUS_AUTO,
+				     battery_capacity, bat_charging,
 				     battery_capacity || bat_charging,
 				     ps_connected);
 		break;
@@ -1334,7 +1340,8 @@ static void wacom_intuos_pro2_bt_battery(struct wacom_wac *wacom)
 	bool chg = data[284] & 0x80;
 	int battery_status = data[284] & 0x7F;
 
-	wacom_notify_battery(wacom, battery_status, chg, 1, chg);
+	wacom_notify_battery(wacom, WACOM_POWER_SUPPLY_STATUS_AUTO,
+			     battery_status, chg, 1, chg);
 }
 
 static int wacom_intuos_pro2_bt_irq(struct wacom_wac *wacom, size_t len)
@@ -1814,6 +1821,7 @@ static void wacom_wac_pad_battery_event(struct hid_device *hdev, struct hid_fiel
 		value = value * 100 / (field->logical_maximum - field->logical_minimum);
 		wacom_wac->hid_data.battery_capacity = value;
 		wacom_wac->hid_data.bat_connected = 1;
+		wacom_wac->hid_data.bat_status = WACOM_POWER_SUPPLY_STATUS_AUTO;
 		break;
 
 	case WACOM_HID_WD_BATTERY_CHARGING:
@@ -1905,13 +1913,14 @@ static void wacom_wac_pad_battery_report(struct hid_device *hdev,
 	struct wacom_features *features = &wacom_wac->features;
 
 	if (features->quirks & WACOM_QUIRK_BATTERY) {
+		int status = wacom_wac->hid_data.bat_status;
 		int capacity = wacom_wac->hid_data.battery_capacity;
 		bool charging = wacom_wac->hid_data.bat_charging;
 		bool connected = wacom_wac->hid_data.bat_connected;
 		bool powered = wacom_wac->hid_data.ps_connected;
 
-		wacom_notify_battery(wacom_wac, capacity, charging,
-				     connected, powered);
+		wacom_notify_battery(wacom_wac, status, capacity,
+				     charging, connected, powered);
 	}
 }
 
@@ -2036,11 +2045,15 @@ static void wacom_wac_pen_event(struct hid_device *hdev, struct hid_field *field
 			wacom_wac->hid_data.sense_state = value;
 		return;
 	case HID_DG_BATTERYSTRENGTH:
-		if (value == 0) /* "not available" */
-			break;
+		if (value == 0) {
+			wacom_wac->hid_data.bat_status = POWER_SUPPLY_STATUS_UNKNOWN;
+		}
+		else {
 			value = value * 100 / (field->logical_maximum - field->logical_minimum);
 			wacom_wac->hid_data.battery_capacity = value;
 			wacom_wac->hid_data.bat_connected = 1;
+			wacom_wac->hid_data.bat_status = WACOM_POWER_SUPPLY_STATUS_AUTO;
+		}
 		break;
 	case HID_DG_INVERT:
 		wacom_wac->hid_data.invert_state = value;
@@ -2818,13 +2831,14 @@ static int wacom_wireless_irq(struct wacom_wac *wacom, size_t len)
 			wacom_schedule_work(wacom, WACOM_WORKER_WIRELESS);
 		}
 
-		wacom_notify_battery(wacom, battery, charging, 1, 0);
+		wacom_notify_battery(wacom, WACOM_POWER_SUPPLY_STATUS_AUTO,
+				     battery, charging, 1, 0);
 
 	} else if (wacom->pid != 0) {
 		/* disconnected while previously connected */
 		wacom->pid = 0;
 		wacom_schedule_work(wacom, WACOM_WORKER_WIRELESS);
-		wacom_notify_battery(wacom, 0, 0, 0, 0);
+		wacom_notify_battery(wacom, POWER_SUPPLY_STATUS_UNKNOWN, 0, 0, 0, 0);
 	}
 
 	return 0;
@@ -2852,8 +2866,8 @@ static int wacom_status_irq(struct wacom_wac *wacom_wac, size_t len)
 		int battery = (data[8] & 0x3f) * 100 / 31;
 		bool charging = !!(data[8] & 0x80);
 
-		wacom_notify_battery(wacom_wac, battery, charging,
-				     battery || charging, 1);
+		wacom_notify_battery(wacom_wac, WACOM_POWER_SUPPLY_STATUS_AUTO,
+				     battery, charging, battery || charging, 1);
 
 		if (!wacom->battery.battery &&
 		    !(features->quirks & WACOM_QUIRK_BATTERY)) {
@@ -2865,7 +2879,7 @@ static int wacom_status_irq(struct wacom_wac *wacom_wac, size_t len)
 		 wacom->battery.battery) {
 		features->quirks &= ~WACOM_QUIRK_BATTERY;
 		wacom_schedule_work(wacom_wac, WACOM_WORKER_BATTERY);
-		wacom_notify_battery(wacom_wac, 0, 0, 0, 0);
+		wacom_notify_battery(wacom_wac, POWER_SUPPLY_STATUS_UNKNOWN, 0, 0, 0, 0);
 	}
 	return 0;
 }

drivers/hid/wacom_wac.h

@@ -96,6 +96,8 @@
 #define WACOM_DEVICETYPE_WL_MONITOR     0x0008
 #define WACOM_DEVICETYPE_DIRECT         0x0010
 
+#define WACOM_POWER_SUPPLY_STATUS_AUTO  -1
+
 #define WACOM_HID_UP_WACOMDIGITIZER     0xff0d0000
 #define WACOM_HID_SP_PAD                0x00040000
 #define WACOM_HID_SP_BUTTON             0x00090000
@@ -297,6 +299,7 @@ struct hid_data {
 	int last_slot_field;
 	int num_expected;
 	int num_received;
+	int bat_status;
 	int battery_capacity;
 	int bat_charging;
 	int bat_connected;