[PATCH 4.19 147/239] HID: quirks: Allow inverting the absolute X/Y values

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Alistair Francis <alistair@alistair23.me>

[ Upstream commit fd8d135b2c5e88662f2729e034913f183455a667 ]

Add a HID_QUIRK_X_INVERT/HID_QUIRK_Y_INVERT quirk that can be used
to invert the X/Y values.

Signed-off-by: Alistair Francis <alistair@alistair23.me>
[bentiss: silence checkpatch warning]
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20211208124045.61815-2-alistair@alistair23.me
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/hid/hid-input.c | 6 ++++++
 include/linux/hid.h     | 2 ++
 2 files changed, 8 insertions(+)

diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index d56ef395eb693..dd3f4aa052980 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -1246,6 +1246,12 @@ void hidinput_hid_event(struct hid_device *hid, struct hid_field *field, struct
 
 	input = field->hidinput->input;
 
+	if (usage->type == EV_ABS &&
+	    (((*quirks & HID_QUIRK_X_INVERT) && usage->code == ABS_X) ||
+	     ((*quirks & HID_QUIRK_Y_INVERT) && usage->code == ABS_Y))) {
+		value = field->logical_maximum - value;
+	}
+
 	if (usage->hat_min < usage->hat_max || usage->hat_dir) {
 		int hat_dir = usage->hat_dir;
 		if (!hat_dir)
diff --git a/include/linux/hid.h b/include/linux/hid.h
index da824ba9fb9a2..c51ebce2197e0 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -353,6 +353,8 @@ struct hid_item {
 /* BIT(9) reserved for backward compatibility, was NO_INIT_INPUT_REPORTS */
 #define HID_QUIRK_ALWAYS_POLL			BIT(10)
 #define HID_QUIRK_INPUT_PER_APP			BIT(11)
+#define HID_QUIRK_X_INVERT			BIT(12)
+#define HID_QUIRK_Y_INVERT			BIT(13)
 #define HID_QUIRK_SKIP_OUTPUT_REPORTS		BIT(16)
 #define HID_QUIRK_SKIP_OUTPUT_REPORT_ID		BIT(17)
 #define HID_QUIRK_NO_OUTPUT_REPORTS_ON_INTR_EP	BIT(18)
-- 
2.34.1