Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/drivers/hid/hid-a4tech.c b/drivers/hid/hid-a4tech.c
index 9428ea7..3a8c4a5 100644
--- a/drivers/hid/hid-a4tech.c
+++ b/drivers/hid/hid-a4tech.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
 /*
  *  HID driver for some a4tech "special" devices
  *
@@ -9,10 +10,6 @@
  */
 
 /*
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License as published by the Free
- * Software Foundation; either version 2 of the License, or (at your option)
- * any later version.
  */
 
 #include <linux/device.h>
@@ -26,20 +23,46 @@
 #define A4_2WHEEL_MOUSE_HACK_7	0x01
 #define A4_2WHEEL_MOUSE_HACK_B8	0x02
 
+#define A4_WHEEL_ORIENTATION	(HID_UP_GENDESK | 0x000000b8)
+
 struct a4tech_sc {
 	unsigned long quirks;
 	unsigned int hw_wheel;
 	__s32 delayed_value;
 };
 
+static int a4_input_mapping(struct hid_device *hdev, struct hid_input *hi,
+			    struct hid_field *field, struct hid_usage *usage,
+			    unsigned long **bit, int *max)
+{
+	struct a4tech_sc *a4 = hid_get_drvdata(hdev);
+
+	if (a4->quirks & A4_2WHEEL_MOUSE_HACK_B8 &&
+	    usage->hid == A4_WHEEL_ORIENTATION) {
+		/*
+		 * We do not want to have this usage mapped to anything as it's
+		 * nonstandard and doesn't really behave like an HID report.
+		 * It's only selecting the orientation (vertical/horizontal) of
+		 * the previous mouse wheel report. The input_events will be
+		 * generated once both reports are recorded in a4_event().
+		 */
+		return -1;
+	}
+
+	return 0;
+
+}
+
 static int a4_input_mapped(struct hid_device *hdev, struct hid_input *hi,
 		struct hid_field *field, struct hid_usage *usage,
 		unsigned long **bit, int *max)
 {
 	struct a4tech_sc *a4 = hid_get_drvdata(hdev);
 
-	if (usage->type == EV_REL && usage->code == REL_WHEEL)
+	if (usage->type == EV_REL && usage->code == REL_WHEEL_HI_RES) {
 		set_bit(REL_HWHEEL, *bit);
+		set_bit(REL_HWHEEL_HI_RES, *bit);
+	}
 
 	if ((a4->quirks & A4_2WHEEL_MOUSE_HACK_7) && usage->hid == 0x00090007)
 		return -1;
@@ -53,21 +76,22 @@
 	struct a4tech_sc *a4 = hid_get_drvdata(hdev);
 	struct input_dev *input;
 
-	if (!(hdev->claimed & HID_CLAIMED_INPUT) || !field->hidinput ||
-			!usage->type)
+	if (!(hdev->claimed & HID_CLAIMED_INPUT) || !field->hidinput)
 		return 0;
 
 	input = field->hidinput->input;
 
 	if (a4->quirks & A4_2WHEEL_MOUSE_HACK_B8) {
-		if (usage->type == EV_REL && usage->code == REL_WHEEL) {
+		if (usage->type == EV_REL && usage->code == REL_WHEEL_HI_RES) {
 			a4->delayed_value = value;
 			return 1;
 		}
 
-		if (usage->hid == 0x000100b8) {
+		if (usage->hid == A4_WHEEL_ORIENTATION) {
 			input_event(input, EV_REL, value ? REL_HWHEEL :
 					REL_WHEEL, a4->delayed_value);
+			input_event(input, EV_REL, value ? REL_HWHEEL_HI_RES :
+					REL_WHEEL_HI_RES, a4->delayed_value * 120);
 			return 1;
 		}
 	}
@@ -77,8 +101,9 @@
 		return 1;
 	}
 
-	if (usage->code == REL_WHEEL && a4->hw_wheel) {
+	if (usage->code == REL_WHEEL_HI_RES && a4->hw_wheel) {
 		input_event(input, usage->type, REL_HWHEEL, value);
+		input_event(input, usage->type, REL_HWHEEL_HI_RES, value * 120);
 		return 1;
 	}
 
@@ -129,6 +154,7 @@
 static struct hid_driver a4_driver = {
 	.name = "a4tech",
 	.id_table = a4_devices,
+	.input_mapping = a4_input_mapping,
 	.input_mapped = a4_input_mapped,
 	.event = a4_event,
 	.probe = a4_probe,