HID: quirks: Allow inverting the absolute X/Y values

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

diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index 4186143..5f357dd 100644 (file)
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -1329,6 +1329,12 @@ 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 ff8b697..a14c089 100644 (file)
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -359,6 +359,8 @@ 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)