This is the first out of five patches me and Simon Wood (CC'd) have been
working on. It separates the handling of Logite from the generic lgff driver
and adds additional features specific for the Logitech wheels, namely

- Native mode support for Driving Force GT, Driving Force Pro, G25 and G27
wheels Every Logitech wheel reports itself as generic Logitech Driving Force
wheel (VID 046d, PID c294). This is done to ensu wheel will work on every USB
HID-aware system even when no Logitech driver is available. It however limits
the capabilit wheel - range is limited to 200 degrees, G25/G27 don't report the
clutch pedal and there is only one combined axis for t brake. The switch to
native mode is done via hardware-specific command which is different for each
wheel. When the wheel receives such command, it simulates reconnect and reports
to the OS with its actual PID.

- Adjustable wheel range DFGT, DFP, G25 and G27 have variable range of the
steering wheel. The range is limited by applying a maximum constant when the
wheel is turned beyond the allowed range. The limit as also set by a
hardware-specific command. There is a comm command for DFGT, G25 and G27 and
another one for DFP. It is probably possible to use the DFP command to limit
the range other Logitech wheels too, but this is not supported by the official
Logitech driver for Windows.  The patch adds a sysfs interface which allows for
the range to be set from userspace.

- Fixed autocentering command All Logitech wheels support FF_AUTOCENTER effect.
The original implementation in the lgff driver didn't work well with patch
fixes it. According to USB communication sniffs the Formula Force EX (pretty
much rebranded original Driving Force accept the generic autocentering command,
this issue is also addressed by the patch

There are still some features this patch doesn't cover, but since some of them
will most likely require modifications of memless driver we have decided not to
include them yet.

As first we decided to move the handling of Logitech wheels from hid-lgff
driver to hid-lg4ff driver (originally used fo At also adds PID of Logitech
Driving Force GT.

Signed-off-by: Michal Malý <madcatxster@gmail.com>
Signed-off-by: Simon Wood <simon@mungewell.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Gere's a small patch to add support for the Logitech G27 wheel, since
the prior patch only added FF support for the Driving Force Pro and G25.
The patch contains the changes from the G25 and DFP, too.

I tested the changes with wine/LFS and got full support for all axes and
buttons.

Signed-off: Peter Gundermann <slim-one@users.sourceforge.net>

Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Small patch to add support for the G25/G27 by adding USB ID's
as suggested by Peter.

Boots but otherwise untested as I don't have hardware, .debs for
kernel (2.6.38) here if want to test/run Ubuntu/Debian:
http://www.mungewell.org/Logitech_Wii_Wheel/

Reported-by: Peter Gundermann <slim-one@users.sourceforge.net>
Signed-off-by: Simon Wood <simon@mungewell.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Neaten current uses of dev_<level> by adding and using
hid specific hid_<level> macros.

Convert existing uses of dev_<level> uses to hid_<level>.
Convert hid-pidff printk uses to hid_<level>.

Remove err_hid and use hid_err instead.

Add missing newlines to logging messages where necessary.
Coalesce format strings.

Add and use pr_fmt(fmt) KBUILD_MODNAME ": " fmt

Other miscellaneous changes:

Add const struct hid_device * argument to hid-core functions
extract() and implement() so hid_<level> can be used by them.
Fix bad indentation in hid-core hid_input_field function
that calls extract() function above.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Implements a new USB-HID for Force Feedback based on the normal
Logitech Force Feedback code and FF-Memless.

Currently only supports the FF_CONSTANT effect although the joystick
appears to support additional non-standard ones.

Signed-off-by: Gary Stein <LordCnidarian@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

list_entry, which is an alias for container_of, cannot return NULL, as
there is no way to add a NULL value to a doubly linked list.

A simplified version of the semantic match that findds this problem is as
follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@r@
expression x,E;
statement S1,S2;
position p,p1;
@@

*x = list_entry@p(...)
... when != x = E
*if@p1 (x == NULL) S1 else S2
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Add force feedback support for Logitech WingMan Formula Force GP
(0x046d/0xc293).

Reported-by: wylda@volny.cz
Tested-by: wylda@volny.cz
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

This patch adds autocentering support for Logitech Force 3D Pro.

Signed-off-by: Sergey Belyashov <Sergey.Belyashov@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Some months ago I send patch which adds autocentering for Logitech MOMO Wheel.
Now I have access to Logitech G25 Racing Wheel and test autocentering for it. I
write patch for current kernel to support autocentering for G25 in legacy mode
(this device supports other modes, but after switching device reconnects with
ID 0xc299 and FF support comes out) and others Logitech (Driving Force,
Formula Force Ex etc) wheels with ID 046d:c294.

Signed-off-by: Sergey Belyashov <Sergey.Belyashov@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>