From 535ea39e39169cb3937be36db6bf880f34044599 Mon Sep 17 00:00:00 2001
From: ond <ond@dement.(none)>
Date: Thu, 10 Mar 2011 20:40:16 +0100
Subject: [PATCH] absolute wheel implementation

---
 hanvon.c | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/hanvon.c b/hanvon.c
index c941a63..2056814 100644
--- a/hanvon.c
+++ b/hanvon.c
@@ -20,6 +20,8 @@ MODULE_LICENSE(DRIVER_LICENSE);
 #define B1	BTN_TOOL_FINGER
 #define B2	BTN_TOOL_PENCIL
 #define B3	BTN_TOOL_AIRBRUSH
+#define TOTAL_WHEEL_ABS	0x40
+#define WHEEL_THRESHOLD	10
 
 struct hanvon {
 	unsigned char *data;
@@ -32,7 +34,7 @@ struct hanvon {
 	unsigned b1:1;
 	unsigned b2:1;
 	unsigned b3:1;
-	int b_wheel;
+	int wheel_pos, old_wheel_pos;
 	int pressure;
 	char phys[32];
 };
@@ -70,9 +72,21 @@ static void hanvon_irq(struct urb *urb)
 				input_report_key(dev, B2, hanvon->b2);
 				input_report_key(dev, B3, hanvon->b3);
 			} else {
-				hanvon->b_wheel = data[2];	// FIXME: calculate position 0 .. 255
+				if(data[2] <= 0x3f) {	// slider area active
+					int diff = hanvon->old_wheel_pos - data[2];
+					if(abs(diff) < WHEEL_THRESHOLD) {
+						hanvon->wheel_pos += diff;
 
-				input_report_key(dev, BTN_WHEEL, hanvon->b_wheel);
+						if(hanvon->wheel_pos < -TOTAL_WHEEL_ABS)
+							hanvon->wheel_pos += TOTAL_WHEEL_ABS;
+						else if(hanvon->wheel_pos > TOTAL_WHEEL_ABS)
+							hanvon->wheel_pos -= TOTAL_WHEEL_ABS;
+
+						input_report_key(dev, ABS_WHEEL, hanvon->wheel_pos);
+					}
+
+					hanvon->old_wheel_pos = data[2];
+				}
 			}
 
 			break;
@@ -120,6 +134,7 @@ static int hanvon_open(struct input_dev *dev)
 {
 	struct hanvon *hanvon = input_get_drvdata(dev);
 
+	hanvon->old_wheel_pos = -TOTAL_WHEEL_ABS-1;
 	hanvon->irq->dev = hanvon->usbdev;
 	if (usb_submit_urb(hanvon->irq, GFP_KERNEL))
 		return -EIO;
@@ -182,6 +197,7 @@ static int hanvon_probe(struct usb_interface *intf, const struct usb_device_id *
 	input_set_abs_params(input_dev, ABS_X, 0, 0x27de, 4, 0);
 	input_set_abs_params(input_dev, ABS_Y, 0, 0x1cfe, 4, 0);
 	input_set_abs_params(input_dev, ABS_PRESSURE, 0, 0xffffffff, 4, 0);
+	input_set_abs_params(input_dev, ABS_WHEEL, 0, TOTAL_WHEEL_ABS, 4, 0);
 
 	endpoint = &intf->cur_altsetting->endpoint[0].desc;