HID: wacom: Perform all event processing as part of report processing

In some cases, we need access to information before it becomes available
to the 'event' handler. In particular, for some devices we cannot properly
process the finger data without first knowing the "contact count" at the
very end of the report (e.g. the Cintiq 24HDT touch screen, when forced
through the GENERIC codepath).

Since the HID subsystem doesn't provide a way to take action before 'event'
is called, we take a cue from hid-multitouch.c and add a pre-process step
within the 'report' handler that performs the same function.
Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>

drivers/hid/wacom_sys.c

@@ -1690,7 +1690,6 @@ static struct hid_driver wacom_driver = {
 	.id_table =	wacom_ids,
 	.probe =	wacom_probe,
 	.remove =	wacom_remove,
-	.event =	wacom_wac_event,
 	.report =	wacom_wac_report,
 #ifdef CONFIG_PM
 	.resume =	wacom_resume,

drivers/hid/wacom_wac.c

@@ -1437,6 +1437,12 @@ static int wacom_wac_pen_event(struct hid_device *hdev, struct hid_field *field,
 	return 0;
 }
 
+static void wacom_wac_pen_pre_report(struct hid_device *hdev,
+		struct hid_report *report)
+{
+	return;
+}
+
 static void wacom_wac_pen_report(struct hid_device *hdev,
 		struct hid_report *report)
 {
@@ -1564,6 +1570,12 @@ static int wacom_wac_finger_event(struct hid_device *hdev,
 	return 0;
 }
 
+static void wacom_wac_finger_pre_report(struct hid_device *hdev,
+		struct hid_report *report)
+{
+	return;
+}
+
 static void wacom_wac_finger_report(struct hid_device *hdev,
 		struct hid_report *report)
 {
@@ -1615,6 +1627,25 @@ int wacom_wac_event(struct hid_device *hdev, struct hid_field *field,
 	return 0;
 }
 
+static void wacom_report_events(struct hid_device *hdev, struct hid_report *report)
+{
+	int r;
+
+	for (r = 0; r < report->maxfield; r++) {
+		struct hid_field *field;
+		unsigned count, n;
+
+		field = report->field[r];
+		count = field->report_count;
+
+		if (!(HID_MAIN_ITEM_VARIABLE & field->flags))
+			continue;
+
+		for (n = 0; n < count; n++)
+			wacom_wac_event(hdev, field, &field->usage[n], field->value[n]);
+	}
+}
+
 void wacom_wac_report(struct hid_device *hdev, struct hid_report *report)
 {
 	struct wacom *wacom = hid_get_drvdata(hdev);
@@ -1624,6 +1655,14 @@ void wacom_wac_report(struct hid_device *hdev, struct hid_report *report)
 	if (wacom_wac->features.type != HID_GENERIC)
 		return;
 
+	if (WACOM_PEN_FIELD(field))
+		wacom_wac_pen_pre_report(hdev, report);
+
+	if (WACOM_FINGER_FIELD(field))
+		wacom_wac_finger_pre_report(hdev, report);
+
+	wacom_report_events(hdev, report);
+
 	if (WACOM_PEN_FIELD(field))
 		return wacom_wac_pen_report(hdev, report);