Commit | Line | Data |
---|---|---|
609d99a3 MCC |
1 | .. _submittingdrivers: |
2 | ||
1da177e4 | 3 | Submitting Drivers For The Linux Kernel |
ceeb1a54 | 4 | ======================================= |
1da177e4 LT |
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 | |
84da7c08 RD |
18 | by the Linux assigned name and number authority (currently this is |
19 | Torben Mathiasen). The site is http://www.lanana.org/. This | |
1da177e4 LT |
20 | also deals with allocating numbers for devices that are not going to |
21 | be submitted to the mainstream kernel. | |
84da7c08 | 22 | See Documentation/devices.txt for more information on this. |
1da177e4 | 23 | |
84da7c08 RD |
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 | |
1da177e4 LT |
26 | have shipped to customers before. |
27 | ||
28 | Who To Submit Drivers To | |
29 | ------------------------ | |
30 | ||
31 | Linux 2.0: | |
5b0ed2c6 | 32 | No new drivers are accepted for this kernel tree. |
1da177e4 LT |
33 | |
34 | Linux 2.2: | |
5b0ed2c6 XVP |
35 | No new drivers are accepted for this kernel tree. |
36 | ||
37 | Linux 2.4: | |
1da177e4 LT |
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 | |
507a6a8c | 41 | maintainer then please contact Willy Tarreau <w@1wt.eu>. |
1da177e4 LT |
42 | |
43 | Linux 2.6: | |
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 | |
e1f8e874 | 46 | submissions is Andrew Morton. |
1da177e4 LT |
47 | |
48 | What Criteria Determine Acceptance | |
49 | ---------------------------------- | |
50 | ||
ceeb1a54 MCC |
51 | Licensing: |
52 | The code must be released to us under the | |
1da177e4 | 53 | GNU General Public License. We don't insist on any kind |
84da7c08 | 54 | of exclusive GPL licensing, and if you wish the driver |
1da177e4 LT |
55 | to be useful to other communities such as BSD you may well |
56 | wish to release under multiple licenses. | |
5b0ed2c6 | 57 | See accepted licenses at include/linux/module.h |
1da177e4 | 58 | |
ceeb1a54 MCC |
59 | Copyright: |
60 | The copyright owner must agree to use of GPL. | |
1da177e4 LT |
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 | |
3706baa8 | 65 | the copyright owner. |
1da177e4 | 66 | |
ceeb1a54 MCC |
67 | Interfaces: |
68 | If your driver uses existing interfaces and behaves like | |
1da177e4 | 69 | other drivers in the same class it will be much more likely |
3706baa8 | 70 | to be accepted than if it invents gratuitous new ones. |
1da177e4 LT |
71 | If you need to implement a common API over Linux and NT |
72 | drivers do it in userspace. | |
73 | ||
ceeb1a54 MCC |
74 | Code: |
75 | Please use the Linux style of code formatting as documented | |
1da177e4 LT |
76 | in Documentation/CodingStyle. If you have sections of code |
77 | that need to be in other formats, for example because they | |
78 | are shared with a windows driver kit and you want to | |
79 | maintain them just once separate them out nicely and note | |
80 | this fact. | |
81 | ||
ceeb1a54 MCC |
82 | Portability: |
83 | Pointers are not always 32bits, not all computers are little | |
1da177e4 LT |
84 | endian, people do not all have floating point and you |
85 | shouldn't use inline x86 assembler in your driver without | |
86 | careful thought. Pure x86 drivers generally are not popular. | |
87 | If you only have x86 hardware it is hard to test portability | |
88 | but it is easy to make sure the code can easily be made | |
89 | portable. | |
90 | ||
ceeb1a54 MCC |
91 | Clarity: |
92 | It helps if anyone can see how to fix the driver. It helps | |
1da177e4 LT |
93 | you because you get patches not bug reports. If you submit a |
94 | driver that intentionally obfuscates how the hardware works | |
95 | it will go in the bitbucket. | |
96 | ||
ceeb1a54 MCC |
97 | PM support: |
98 | Since Linux is used on many portable and desktop systems, your | |
5b795202 RW |
99 | driver is likely to be used on such a system and therefore it |
100 | should support basic power management by implementing, if | |
101 | necessary, the .suspend and .resume methods used during the | |
102 | system-wide suspend and resume transitions. You should verify | |
103 | that your driver correctly handles the suspend and resume, but | |
104 | if you are unable to ensure that, please at least define the | |
105 | .suspend method returning the -ENOSYS ("Function not | |
106 | implemented") error. You should also try to make sure that your | |
107 | driver uses as little power as possible when it's not doing | |
108 | anything. For the driver testing instructions see | |
109 | Documentation/power/drivers-testing.txt and for a relatively | |
110 | complete overview of the power management issues related to | |
111 | drivers see Documentation/power/devices.txt . | |
112 | ||
ceeb1a54 MCC |
113 | Control: |
114 | In general if there is active maintenance of a driver by | |
3706baa8 | 115 | the author then patches will be redirected to them unless |
1da177e4 LT |
116 | they are totally obvious and without need of checking. |
117 | If you want to be the contact and update point for the | |
118 | driver it is a good idea to state this in the comments, | |
119 | and include an entry in MAINTAINERS for your driver. | |
120 | ||
121 | What Criteria Do Not Determine Acceptance | |
122 | ----------------------------------------- | |
123 | ||
ceeb1a54 MCC |
124 | Vendor: |
125 | Being the hardware vendor and maintaining the driver is | |
1da177e4 LT |
126 | often a good thing. If there is a stable working driver from |
127 | other people already in the tree don't expect 'we are the | |
3706baa8 | 128 | vendor' to get your driver chosen. Ideally work with the |
1da177e4 LT |
129 | existing driver author to build a single perfect driver. |
130 | ||
ceeb1a54 MCC |
131 | Author: |
132 | It doesn't matter if a large Linux company wrote the driver, | |
1da177e4 LT |
133 | or you did. Nobody has any special access to the kernel |
134 | tree. Anyone who tells you otherwise isn't telling the | |
135 | whole story. | |
136 | ||
137 | ||
138 | Resources | |
139 | --------- | |
140 | ||
141 | Linux kernel master tree: | |
ceeb1a54 MCC |
142 | ftp.\ *country_code*\ .kernel.org:/pub/linux/kernel/... |
143 | ||
144 | where *country_code* == your country code, such as | |
145 | **us**, **uk**, **fr**, etc. | |
1da177e4 | 146 | |
399e1d9c | 147 | http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git |
6d06b81b | 148 | |
3706baa8 | 149 | Linux kernel mailing list: |
1da177e4 LT |
150 | linux-kernel@vger.kernel.org |
151 | [mail majordomo@vger.kernel.org to subscribe] | |
152 | ||
153 | Linux Device Drivers, Third Edition (covers 2.6.10): | |
154 | http://lwn.net/Kernel/LDD3/ (free version) | |
155 | ||
1da177e4 LT |
156 | LWN.net: |
157 | Weekly summary of kernel development activity - http://lwn.net/ | |
ceeb1a54 | 158 | |
1da177e4 | 159 | 2.6 API changes: |
ceeb1a54 | 160 | |
1da177e4 | 161 | http://lwn.net/Articles/2.6-kernel-api/ |
ceeb1a54 | 162 | |
1da177e4 | 163 | Porting drivers from prior kernels to 2.6: |
ceeb1a54 | 164 | |
1da177e4 LT |
165 | http://lwn.net/Articles/driver-porting/ |
166 | ||
1da177e4 LT |
167 | KernelNewbies: |
168 | Documentation and assistance for new kernel programmers | |
ceeb1a54 MCC |
169 | |
170 | http://kernelnewbies.org/ | |
1da177e4 LT |
171 | |
172 | Linux USB project: | |
e1b114ee | 173 | http://www.linux-usb.org/ |
5b0ed2c6 | 174 | |
3706baa8 AD |
175 | How to NOT write kernel driver by Arjan van de Ven: |
176 | http://www.fenrus.org/how-to-not-write-a-device-driver-paper.pdf | |
5b0ed2c6 XVP |
177 | |
178 | Kernel Janitor: | |
0ea6e611 | 179 | http://kernelnewbies.org/KernelJanitors |
6d06b81b AA |
180 | |
181 | GIT, Fast Version Control System: | |
182 | http://git-scm.com/ |