From:   Alistair Francis <alistair@alistair23.me>
To:     benjamin.tissoires@redhat.com, shawnguo@kernel.org,
        s.hauer@pengutronix.de, dmitry.torokhov@gmail.com
Cc:     Ping.Cheng@wacom.com, linux-arm-kernel@lists.infradead.org,
        linux-imx@nxp.com, alistair23@gmail.com,
        tatsunosuke.tobita@wacom.com, linux-input@vger.kernel.org,
        Jason.Gerecke@wacom.com, linux-kernel@vger.kernel.org,
        jikos@kernel.org, martin.chen@wacom.com,
        devicetree@vger.kernel.org,
        Alistair Francis <alistair@alistair23.me>
Subject: [PATCH v15 1/3] HID: quirks: Allow inverting the absolute X/Y values
Date:   Thu,  2 Dec 2021 21:56:20 +1000
Message-Id: <20211202115622.40153-2-alistair@alistair23.me>
In-Reply-To: <20211202115622.40153-1-alistair@alistair23.me>
References: <20211202115622.40153-1-alistair@alistair23.me>
MIME-Version: 1.0
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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>
---
 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 217f2d1b91c5..83ee803186a1 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -1331,6 +1331,12 @@ 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 9e067f937dbc..4959385ca588 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -349,6 +349,8 @@ 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)
-- 
2.31.1