[PATCH v2] HID: wacom: Correct distance scale for 2nd-gen Intuos devices

From: "Gerecke, Jason" <killertofu@gmail.com>
To: linux-input@vger.kernel.org, Jiri Kosina <jikos@kernel.org>,
	Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: Ping Cheng <pinglinux@gmail.com>,
	Aaron Armstrong Skomra <skomra@gmail.com>,
	Greg KH <gregkh@linuxfoundation.org>,
	Jason Gerecke <jason.gerecke@wacom.com>,
	stable@vger.kernel.org
Subject: [PATCH v2] HID: wacom: Correct distance scale for 2nd-gen Intuos devices
Date: Wed,  7 Aug 2019 14:11:55 -0700	[thread overview]
Message-ID: <20190807211155.4280-1-jason.gerecke@wacom.com> (raw)
In-Reply-To: <20190807051839.GA26833@kroah.com>

From: Jason Gerecke <jason.gerecke@wacom.com>

Distance values reported by 2nd-gen Intuos tablets are on an inverted
scale (0 == far, 63 == near). We need to change them over to a normal
scale before reporting to userspace or else userspace drivers and
applications can get confused.

Ref: https://github.com/linuxwacom/input-wacom/issues/98
Fixes: eda01dab53 ("HID: wacom: Add four new Intuos devices")
Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Cc: <stable@vger.kernel.org> # v4.4+
---
Make checkpatch happy -- *doh!*

 drivers/hid/wacom_wac.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/hid/wacom_wac.c b/drivers/hid/wacom_wac.c
index 7a8ddc999a8e..8e5063492242 100644
--- a/drivers/hid/wacom_wac.c
+++ b/drivers/hid/wacom_wac.c
@@ -846,6 +846,8 @@ static int wacom_intuos_general(struct wacom_wac *wacom)
 		y >>= 1;
 		distance >>= 1;
 	}
+	if (features->type == INTUOSHT2)
+		distance = features->distance_max - distance;
 	input_report_abs(input, ABS_X, x);
 	input_report_abs(input, ABS_Y, y);
 	input_report_abs(input, ABS_DISTANCE, distance);
-- 
2.22.0

