HID: wacom: generic: support touch on/off softkey

Wacom Cintiq Pro has a softkey to turn touch on/off. Since it is
a softkey, hardware/firmware still reports touch events no matter
what state the softkey is. We need to ignore touch events when
the key is in off mode.
Signed-off-by: Ping Cheng <ping.cheng@wacom.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Tested-by: Aaron Armstrong Skomra <aaron.skomra@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/wacom_sys.c

@@ -2100,8 +2100,10 @@ static void wacom_set_shared_values(struct wacom_wac *wacom_wac)
 		wacom_wac->shared->touch_input = wacom_wac->touch_input;
 	}
 
-	if (wacom_wac->has_mute_touch_switch)
+	if (wacom_wac->has_mute_touch_switch) {
 		wacom_wac->shared->has_mute_touch_switch = true;
+		wacom_wac->shared->is_touch_on = true;
+	}
 
 	if (wacom_wac->shared->has_mute_touch_switch &&
 	    wacom_wac->shared->touch_input) {

drivers/hid/wacom_wac.c

@@ -1739,6 +1739,7 @@ static void wacom_wac_pad_usage_mapping(struct hid_device *hdev,
 		features->device_type |= WACOM_DEVICETYPE_PAD;
 		break;
 	case WACOM_HID_WD_TOUCHONOFF:
+	case WACOM_HID_WD_MUTE_DEVICE:
 		/*
 		 * This usage, which is used to mute touch events, comes
 		 * from the pad packet, but is reported on the touch
@@ -1831,6 +1832,7 @@ static void wacom_wac_pad_event(struct hid_device *hdev, struct hid_field *field
 	struct wacom_features *features = &wacom_wac->features;
 	unsigned equivalent_usage = wacom_equivalent_usage(usage->hid);
 	int i;
+	bool is_touch_on = value;
 
 	/*
 	 * Avoid reporting this event and setting inrange_state if this usage
@@ -1850,10 +1852,17 @@ static void wacom_wac_pad_event(struct hid_device *hdev, struct hid_field *field
 			input_event(input, usage->type, usage->code, 0);
 		break;
 
+	case WACOM_HID_WD_MUTE_DEVICE:
+		if (wacom_wac->shared->touch_input && value) {
+			wacom_wac->shared->is_touch_on = !wacom_wac->shared->is_touch_on;
+			is_touch_on = wacom_wac->shared->is_touch_on;
+		}
+
+		/* fall through*/
 	case WACOM_HID_WD_TOUCHONOFF:
 		if (wacom_wac->shared->touch_input) {
 			input_report_switch(wacom_wac->shared->touch_input,
-					    SW_MUTE_DEVICE, !value);
+					    SW_MUTE_DEVICE, !is_touch_on);
 			input_sync(wacom_wac->shared->touch_input);
 		}
 		break;
@@ -2212,6 +2221,13 @@ static void wacom_wac_finger_slot(struct wacom_wac *wacom_wac,
 	bool prox = hid_data->tipswitch &&
 		    report_touch_events(wacom_wac);
 
+	if (wacom_wac->shared->has_mute_touch_switch &&
+	    !wacom_wac->shared->is_touch_on) {
+		if (!wacom_wac->shared->touch_down)
+			return;
+		prox = 0;
+	}
+
 	wacom_wac->hid_data.num_received++;
 	if (wacom_wac->hid_data.num_received > wacom_wac->hid_data.num_expected)
 		return;

drivers/hid/wacom_wac.h

@@ -121,6 +121,7 @@
 #define WACOM_HID_WD_EXPRESSKEY00       (WACOM_HID_UP_WACOMDIGITIZER | 0x0910)
 #define WACOM_HID_WD_EXPRESSKEYCAP00    (WACOM_HID_UP_WACOMDIGITIZER | 0x0950)
 #define WACOM_HID_WD_MODE_CHANGE        (WACOM_HID_UP_WACOMDIGITIZER | 0x0980)
+#define WACOM_HID_WD_MUTE_DEVICE        (WACOM_HID_UP_WACOMDIGITIZER | 0x0981)
 #define WACOM_HID_WD_CONTROLPANEL       (WACOM_HID_UP_WACOMDIGITIZER | 0x0982)
 #define WACOM_HID_WD_ONSCREEN_KEYBOARD  (WACOM_HID_UP_WACOMDIGITIZER | 0x0983)
 #define WACOM_HID_WD_BUTTONCONFIG       (WACOM_HID_UP_WACOMDIGITIZER | 0x0986)
@@ -274,6 +275,7 @@ struct wacom_shared {
 	struct hid_device *pen;
 	struct hid_device *touch;
 	bool has_mute_touch_switch;
+	bool is_touch_on;
 };
 
 struct hid_data {