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Based on kernel version 4.9. Page generated on 2016-12-21 14:37 EST.

1	.. _submittingdrivers:
2	
3	Submitting Drivers For The Linux Kernel
4	=======================================
5	
6	This document is intended to explain how to submit device drivers to the
7	various kernel trees. Note that if you are interested in video card drivers
8	you should probably talk to XFree86 (http://www.xfree86.org/) and/or X.Org
9	(http://x.org/) instead.
10	
11	Also read the Documentation/SubmittingPatches document.
12	
13	
14	Allocating Device Numbers
15	-------------------------
16	
17	Major and minor numbers for block and character devices are allocated
18	by the Linux assigned name and number authority (currently this is
19	Torben Mathiasen). The site is http://www.lanana.org/. This
20	also deals with allocating numbers for devices that are not going to
21	be submitted to the mainstream kernel.
22	See Documentation/devices.txt for more information on this.
23	
24	If you don't use assigned numbers then when your device is submitted it will
25	be given an assigned number even if that is different from values you may
26	have shipped to customers before.
27	
28	Who To Submit Drivers To
29	------------------------
30	
31	Linux 2.0:
32		No new drivers are accepted for this kernel tree.
33	
34	Linux 2.2:
35		No new drivers are accepted for this kernel tree.
36	
37	Linux 2.4:
38		If the code area has a general maintainer then please submit it to
39		the maintainer listed in MAINTAINERS in the kernel file. If the
40		maintainer does not respond or you cannot find the appropriate
41		maintainer then please contact Willy Tarreau <w@1wt.eu>.
42	
43	Linux 2.6 and upper:
44		The same rules apply as 2.4 except that you should follow linux-kernel
45		to track changes in API's. The final contact point for Linux 2.6+
46		submissions is Andrew Morton.
47	
48	What Criteria Determine Acceptance
49	----------------------------------
50	
51	Licensing:
52			The code must be released to us under the
53			GNU General Public License. We don't insist on any kind
54			of exclusive GPL licensing, and if you wish the driver
55			to be useful to other communities such as BSD you may well
56			wish to release under multiple licenses.
57			See accepted licenses at include/linux/module.h
58	
59	Copyright:
60			The copyright owner must agree to use of GPL.
61			It's best if the submitter and copyright owner
62			are the same person/entity. If not, the name of
63			the person/entity authorizing use of GPL should be
64			listed in case it's necessary to verify the will of
65			the copyright owner.
66	
67	Interfaces:
68			If your driver uses existing interfaces and behaves like
69			other drivers in the same class it will be much more likely
70			to be accepted than if it invents gratuitous new ones.
71			If you need to implement a common API over Linux and NT
72			drivers do it in userspace.
73	
74	Code:
75			Please use the Linux style of code formatting as documented
76			in :ref:`Documentation/CodingStyle <codingStyle>`.
77			If you have sections of code
78			that need to be in other formats, for example because they
79			are shared with a windows driver kit and you want to
80			maintain them just once separate them out nicely and note
81			this fact.
82	
83	Portability:
84			Pointers are not always 32bits, not all computers are little
85			endian, people do not all have floating point and you
86			shouldn't use inline x86 assembler in your driver without
87			careful thought. Pure x86 drivers generally are not popular.
88			If you only have x86 hardware it is hard to test portability
89			but it is easy to make sure the code can easily be made
90			portable.
91	
92	Clarity:
93			It helps if anyone can see how to fix the driver. It helps
94			you because you get patches not bug reports. If you submit a
95			driver that intentionally obfuscates how the hardware works
96			it will go in the bitbucket.
97	
98	PM support:
99			Since Linux is used on many portable and desktop systems, your
100			driver is likely to be used on such a system and therefore it
101			should support basic power management by implementing, if
102			necessary, the .suspend and .resume methods used during the
103			system-wide suspend and resume transitions.  You should verify
104			that your driver correctly handles the suspend and resume, but
105			if you are unable to ensure that, please at least define the
106			.suspend method returning the -ENOSYS ("Function not
107			implemented") error.  You should also try to make sure that your
108			driver uses as little power as possible when it's not doing
109			anything.  For the driver testing instructions see
110			Documentation/power/drivers-testing.txt and for a relatively
111			complete overview of the power management issues related to
112			drivers see Documentation/power/devices.txt .
113	
114	Control:
115			In general if there is active maintenance of a driver by
116			the author then patches will be redirected to them unless
117			they are totally obvious and without need of checking.
118			If you want to be the contact and update point for the
119			driver it is a good idea to state this in the comments,
120			and include an entry in MAINTAINERS for your driver.
121	
122	What Criteria Do Not Determine Acceptance
123	-----------------------------------------
124	
125	Vendor:
126			Being the hardware vendor and maintaining the driver is
127			often a good thing. If there is a stable working driver from
128			other people already in the tree don't expect 'we are the
129			vendor' to get your driver chosen. Ideally work with the
130			existing driver author to build a single perfect driver.
131	
132	Author:
133			It doesn't matter if a large Linux company wrote the driver,
134			or you did. Nobody has any special access to the kernel
135			tree. Anyone who tells you otherwise isn't telling the
136			whole story.
137	
138	
139	Resources
140	---------
141	
142	Linux kernel master tree:
143		ftp.\ *country_code*\ .kernel.org:/pub/linux/kernel/...
144	
145		where *country_code* == your country code, such as
146		**us**, **uk**, **fr**, etc.
147	
148		http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git
149	
150	Linux kernel mailing list:
151		linux-kernel@vger.kernel.org
152		[mail majordomo@vger.kernel.org to subscribe]
153	
154	Linux Device Drivers, Third Edition (covers 2.6.10):
155		http://lwn.net/Kernel/LDD3/  (free version)
156	
157	LWN.net:
158		Weekly summary of kernel development activity - http://lwn.net/
159	
160		2.6 API changes:
161	
162			http://lwn.net/Articles/2.6-kernel-api/
163	
164		Porting drivers from prior kernels to 2.6:
165	
166			http://lwn.net/Articles/driver-porting/
167	
168	KernelNewbies:
169		Documentation and assistance for new kernel programmers
170	
171			http://kernelnewbies.org/
172	
173	Linux USB project:
174		http://www.linux-usb.org/
175	
176	How to NOT write kernel driver by Arjan van de Ven:
177		http://www.fenrus.org/how-to-not-write-a-device-driver-paper.pdf
178	
179	Kernel Janitor:
180		http://kernelnewbies.org/KernelJanitors
181	
182	GIT, Fast Version Control System:
183		http://git-scm.com/
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