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Based on kernel version 3.15.4. Page generated on 2014-07-07 09:04 EST.

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