Re: [PATCH v2 1/4] hid-multitouch: Auto detection of maxcontacts

@@ -126,9 +127,19 @@ struct mt_class mt_classes[] = {
 static void mt_feature_mapping(struct hid_device *hdev,
 		struct hid_field *field, struct hid_usage *usage)
 {
-	if (usage->hid == HID_DG_INPUTMODE) {
-		struct mt_device *td = hid_get_drvdata(hdev);
+	struct mt_device *td = hid_get_drvdata(hdev);
+
+	switch (usage->hid) {
+	case HID_DG_INPUTMODE:
 		td->inputmode = field->report->id;
+		break;
+	case HID_DG_CONTACTMAX:
+		td->maxcontacts = *(field->value);

+		if (td->mtclass->maxcontacts > td->maxcontacts)
+			/* check if the maxcontacts is given by the class */
+			td->maxcontacts = td->mtclass->maxcontacts;
+
+		break;
 	}
 }
 

@@ -317,7 +327,7 @@ static int mt_event(struct hid_device *hid, struct hid_field *field,
 	struct mt_device *td = hid_get_drvdata(hid);
 	__s32 quirks = td->mtclass->quirks;
 
-	if (hid->claimed & HID_CLAIMED_INPUT) {
+	if (hid->claimed & HID_CLAIMED_INPUT && td->slots) {

 		switch (usage->hid) {
 		case HID_DG_INRANGE:
 			if (quirks & MT_QUIRK_VALID_IS_INRANGE)

@@ -415,9 +425,7 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
 	 */
 	hdev->quirks |= HID_QUIRK_NO_INPUT_SYNC;
 
-	td = kzalloc(sizeof(struct mt_device) +
-				mtclass->maxcontacts * sizeof(struct mt_slot),
-				GFP_KERNEL);
+	td = kzalloc(sizeof(struct mt_device), GFP_KERNEL);
 	if (!td) {
 		dev_err(&hdev->dev, "cannot allocate multitouch data\n");
 		return -ENOMEM;

@@ -434,6 +442,14 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
 	if (ret)
 		goto fail;
 
+	td->slots = kzalloc(td->maxcontacts * sizeof(struct mt_slot),
+				GFP_KERNEL);
+	if (!td->slots) {
+		dev_err(&hdev->dev, "cannot allocate multitouch slots\n");
+		ret = -ENOMEM;
+		goto fail;

+	}
+
 	mt_set_input_mode(hdev);
 
 	return 0;

@@ -455,6 +471,7 @@ static void mt_remove(struct hid_device *hdev)
 {
 	struct mt_device *td = hid_get_drvdata(hdev);
 	hid_hw_stop(hdev);
+	kfree(td->slots);
 	kfree(td);
 	hid_set_drvdata(hdev, NULL);
 }

-- 
1.7.4