[3.11.y.z extended stable] Patch "HID:hid-lg4ff: Scale autocentering force properly on Logitech wheel" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    HID:hid-lg4ff: Scale autocentering force properly on Logitech wheel

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 0908a4ade57528271f837baf5a03b7eacc6e084c Mon Sep 17 00:00:00 2001
From: Simon Wood <simon at mungewell.org>
Date: Wed, 6 Nov 2013 12:30:40 -0700
Subject: HID:hid-lg4ff: Scale autocentering force properly on Logitech wheel

commit f8c231569a7a455dfa1907294a46ba52b3aa8859 upstream.

Adjust the scaling and lineartity to match that of the Windows
driver (from MOMO testing).

Reported-by: Elias Vanderstuyft <elias.vds at gmail.com>
Signed-off-by: Simon Wood <simon at mungewell.org>
Signed-off-by: Jiri Kosina <jkosina at suse.cz>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/hid/hid-lg4ff.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/hid/hid-lg4ff.c b/drivers/hid/hid-lg4ff.c
index 8782fe1..530fcd19 100644
--- a/drivers/hid/hid-lg4ff.c
+++ b/drivers/hid/hid-lg4ff.c
@@ -218,12 +218,21 @@ static void hid_lg4ff_set_autocenter_default(struct input_dev *dev, u16 magnitud
 	struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
 	struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
 	__s32 *value = report->field[0]->value;
+	__u32 expand_a, expand_b;
+
+	if (magnitude <= 0xaaaa) {
+		expand_a = 0x0c * magnitude;
+		expand_b = 0x80 * magnitude;
+	} else {
+		expand_a = (0x0c * 0xaaaa) + 0x06 * (magnitude - 0xaaaa);
+		expand_b = (0x80 * 0xaaaa) + 0xff * (magnitude - 0xaaaa);
+	}

 	value[0] = 0xfe;
 	value[1] = 0x0d;
-	value[2] = magnitude >> 13;
-	value[3] = magnitude >> 13;
-	value[4] = magnitude >> 8;
+	value[2] = expand_a / 0xaaaa;
+	value[3] = expand_a / 0xaaaa;
+	value[4] = expand_b / 0xaaaa;
 	value[5] = 0x00;
 	value[6] = 0x00;

--
1.8.3.2