From 78f1e818cf70711a4834fc008f87077b12fbb9f2 Mon Sep 17 00:00:00 2001
From: Jake Day <jake@ninebysix.com>
Date: Tue, 7 Nov 2017 20:14:55 -0500
Subject: [PATCH] fix for multi-touch hid input

---
 kernel/drivers/hid/hid-multitouch.c | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/kernel/drivers/hid/hid-multitouch.c b/kernel/drivers/hid/hid-multitouch.c
index f66abb6e7..1cfbd26fb 100644
--- a/kernel/drivers/hid/hid-multitouch.c
+++ b/kernel/drivers/hid/hid-multitouch.c
@@ -140,6 +140,7 @@ struct mt_device {
 
 static void mt_post_parse_default_settings(struct mt_device *td);
 static void mt_post_parse(struct mt_device *td);
+static int cc_seen = 0;
 
 /* classes of device behavior */
 #define MT_CLS_DEFAULT				0x0001
@@ -589,11 +590,11 @@ static int mt_touch_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 			    usage->usage_index >= field->report_count)
 				return 1;
 
-			//if (td->cc_index < 0) {
+			if(cc_seen != 1) {
 				td->cc_index = field->index;
 				td->cc_value_index = usage->usage_index;
-			//}
-
+				cc_seen++;
+			}
 			return 1;
 		case HID_DG_CONTACTMAX:
 			/* we don't set td->last_slot_field as contactcount and
@@ -630,6 +631,16 @@ static int mt_touch_input_mapping(struct hid_device *hdev, struct hid_input *hi,
 	return 0;
 }
 
+static int mt_touch_input_mapped(struct hid_device *hdev, struct hid_input *hi,
+		struct hid_field *field, struct hid_usage *usage,
+		unsigned long **bit, int *max)
+{
+	if (usage->type == EV_KEY || usage->type == EV_ABS)
+		set_bit(usage->type, hi->input->evbit);
+
+	return -1;
+}
+
 static int mt_compute_slot(struct mt_device *td, struct input_dev *input)
 {
 	__s32 quirks = td->mtclass.quirks;
@@ -1000,10 +1011,8 @@ static int mt_input_mapped(struct hid_device *hdev, struct hid_input *hi,
 		return 0;
 
 	if (field->application == HID_DG_TOUCHSCREEN ||
-	    field->application == HID_DG_TOUCHPAD) {
-		/* We own these mappings, tell hid-input to ignore them */
-		return -1;
-	}
+	    field->application == HID_DG_TOUCHPAD)
+		return mt_touch_input_mapped(hdev, hi, field, usage, bit, max);
 
 	/* let hid-core decide for the others */
 	return 0;
@@ -1292,6 +1301,7 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
 	td->inputmode_value = MT_INPUTMODE_TOUCHSCREEN;
 	td->cc_index = -1;
 	td->mt_report_id = -1;
+	cc_seen = 0;
 	hid_set_drvdata(hdev, td);
 
 	td->fields = devm_kzalloc(&hdev->dev, sizeof(struct mt_fields),
@@ -1338,7 +1348,6 @@ static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)
 	hdev->quirks |= HID_QUIRK_NO_INIT_REPORTS;
 
 	setup_timer(&td->release_timer, mt_expired_timeout, (long)hdev);
-
 	ret = hid_parse(hdev);
 	if (ret != 0)
 		return ret;