mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-27 19:29:37 +00:00
![Pranith Kumar](/assets/img/avatar_default.png)
kerneltrap.org no longer works, remove the dead reference Signed-off-by: Pranith Kumar <bobby.prani@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
163 lines
6.2 KiB
Text
163 lines
6.2 KiB
Text
Submitting Drivers For The Linux Kernel
|
|
---------------------------------------
|
|
|
|
This document is intended to explain how to submit device drivers to the
|
|
various kernel trees. Note that if you are interested in video card drivers
|
|
you should probably talk to XFree86 (http://www.xfree86.org/) and/or X.Org
|
|
(http://x.org/) instead.
|
|
|
|
Also read the Documentation/SubmittingPatches document.
|
|
|
|
|
|
Allocating Device Numbers
|
|
-------------------------
|
|
|
|
Major and minor numbers for block and character devices are allocated
|
|
by the Linux assigned name and number authority (currently this is
|
|
Torben Mathiasen). The site is http://www.lanana.org/. This
|
|
also deals with allocating numbers for devices that are not going to
|
|
be submitted to the mainstream kernel.
|
|
See Documentation/devices.txt for more information on this.
|
|
|
|
If you don't use assigned numbers then when your device is submitted it will
|
|
be given an assigned number even if that is different from values you may
|
|
have shipped to customers before.
|
|
|
|
Who To Submit Drivers To
|
|
------------------------
|
|
|
|
Linux 2.0:
|
|
No new drivers are accepted for this kernel tree.
|
|
|
|
Linux 2.2:
|
|
No new drivers are accepted for this kernel tree.
|
|
|
|
Linux 2.4:
|
|
If the code area has a general maintainer then please submit it to
|
|
the maintainer listed in MAINTAINERS in the kernel file. If the
|
|
maintainer does not respond or you cannot find the appropriate
|
|
maintainer then please contact Willy Tarreau <w@1wt.eu>.
|
|
|
|
Linux 2.6:
|
|
The same rules apply as 2.4 except that you should follow linux-kernel
|
|
to track changes in API's. The final contact point for Linux 2.6
|
|
submissions is Andrew Morton.
|
|
|
|
What Criteria Determine Acceptance
|
|
----------------------------------
|
|
|
|
Licensing: The code must be released to us under the
|
|
GNU General Public License. We don't insist on any kind
|
|
of exclusive GPL licensing, and if you wish the driver
|
|
to be useful to other communities such as BSD you may well
|
|
wish to release under multiple licenses.
|
|
See accepted licenses at include/linux/module.h
|
|
|
|
Copyright: The copyright owner must agree to use of GPL.
|
|
It's best if the submitter and copyright owner
|
|
are the same person/entity. If not, the name of
|
|
the person/entity authorizing use of GPL should be
|
|
listed in case it's necessary to verify the will of
|
|
the copyright owner.
|
|
|
|
Interfaces: If your driver uses existing interfaces and behaves like
|
|
other drivers in the same class it will be much more likely
|
|
to be accepted than if it invents gratuitous new ones.
|
|
If you need to implement a common API over Linux and NT
|
|
drivers do it in userspace.
|
|
|
|
Code: Please use the Linux style of code formatting as documented
|
|
in Documentation/CodingStyle. If you have sections of code
|
|
that need to be in other formats, for example because they
|
|
are shared with a windows driver kit and you want to
|
|
maintain them just once separate them out nicely and note
|
|
this fact.
|
|
|
|
Portability: Pointers are not always 32bits, not all computers are little
|
|
endian, people do not all have floating point and you
|
|
shouldn't use inline x86 assembler in your driver without
|
|
careful thought. Pure x86 drivers generally are not popular.
|
|
If you only have x86 hardware it is hard to test portability
|
|
but it is easy to make sure the code can easily be made
|
|
portable.
|
|
|
|
Clarity: It helps if anyone can see how to fix the driver. It helps
|
|
you because you get patches not bug reports. If you submit a
|
|
driver that intentionally obfuscates how the hardware works
|
|
it will go in the bitbucket.
|
|
|
|
PM support: Since Linux is used on many portable and desktop systems, your
|
|
driver is likely to be used on such a system and therefore it
|
|
should support basic power management by implementing, if
|
|
necessary, the .suspend and .resume methods used during the
|
|
system-wide suspend and resume transitions. You should verify
|
|
that your driver correctly handles the suspend and resume, but
|
|
if you are unable to ensure that, please at least define the
|
|
.suspend method returning the -ENOSYS ("Function not
|
|
implemented") error. You should also try to make sure that your
|
|
driver uses as little power as possible when it's not doing
|
|
anything. For the driver testing instructions see
|
|
Documentation/power/drivers-testing.txt and for a relatively
|
|
complete overview of the power management issues related to
|
|
drivers see Documentation/power/devices.txt .
|
|
|
|
Control: In general if there is active maintenance of a driver by
|
|
the author then patches will be redirected to them unless
|
|
they are totally obvious and without need of checking.
|
|
If you want to be the contact and update point for the
|
|
driver it is a good idea to state this in the comments,
|
|
and include an entry in MAINTAINERS for your driver.
|
|
|
|
What Criteria Do Not Determine Acceptance
|
|
-----------------------------------------
|
|
|
|
Vendor: Being the hardware vendor and maintaining the driver is
|
|
often a good thing. If there is a stable working driver from
|
|
other people already in the tree don't expect 'we are the
|
|
vendor' to get your driver chosen. Ideally work with the
|
|
existing driver author to build a single perfect driver.
|
|
|
|
Author: It doesn't matter if a large Linux company wrote the driver,
|
|
or you did. Nobody has any special access to the kernel
|
|
tree. Anyone who tells you otherwise isn't telling the
|
|
whole story.
|
|
|
|
|
|
Resources
|
|
---------
|
|
|
|
Linux kernel master tree:
|
|
ftp.??.kernel.org:/pub/linux/kernel/...
|
|
?? == your country code, such as "us", "uk", "fr", etc.
|
|
|
|
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git
|
|
|
|
Linux kernel mailing list:
|
|
linux-kernel@vger.kernel.org
|
|
[mail majordomo@vger.kernel.org to subscribe]
|
|
|
|
Linux Device Drivers, Third Edition (covers 2.6.10):
|
|
http://lwn.net/Kernel/LDD3/ (free version)
|
|
|
|
LWN.net:
|
|
Weekly summary of kernel development activity - http://lwn.net/
|
|
2.6 API changes:
|
|
http://lwn.net/Articles/2.6-kernel-api/
|
|
Porting drivers from prior kernels to 2.6:
|
|
http://lwn.net/Articles/driver-porting/
|
|
|
|
KernelNewbies:
|
|
Documentation and assistance for new kernel programmers
|
|
http://kernelnewbies.org/
|
|
|
|
Linux USB project:
|
|
http://www.linux-usb.org/
|
|
|
|
How to NOT write kernel driver by Arjan van de Ven:
|
|
http://www.fenrus.org/how-to-not-write-a-device-driver-paper.pdf
|
|
|
|
Kernel Janitor:
|
|
http://kernelnewbies.org/KernelJanitors
|
|
|
|
GIT, Fast Version Control System:
|
|
http://git-scm.com/
|