1Submitting Drivers For The Linux Kernel 2--------------------------------------- 3 4This document is intended to explain how to submit device drivers to the 5various kernel trees. Note that if you are interested in video card drivers 6you should probably talk to XFree86 (http://www.xfree86.org) instead. 7 8Also read the Documentation/SubmittingPatches document. 9 10 11Allocating Device Numbers 12------------------------- 13 14Major and minor numbers for block and character devices are allocated 15by the Linux assigned name and number authority (currently better 16known as H Peter Anvin). The site is http://www.lanana.org/. This 17also deals with allocating numbers for devices that are not going to 18be submitted to the mainstream kernel. 19 20If you don't use assigned numbers then when you device is submitted it will 21get given an assigned number even if that is different from values you may 22have shipped to customers before. 23 24Who To Submit Drivers To 25------------------------ 26 27Linux 2.0: 28 No new drivers are accepted for this kernel tree 29 30Linux 2.2: 31 If the code area has a general maintainer then please submit it to 32 the maintainer listed in MAINTAINERS in the kernel file. If the 33 maintainer does not respond or you cannot find the appropriate 34 maintainer then please contact Alan Cox <alan@lxorguk.ukuu.org.uk> 35 36Linux 2.4: 37 The same rules apply as 2.2. The final contact point for Linux 2.4 38 submissions is Marcelo Tosatti <marcelo.tosatti@cyclades.com>. 39 40Linux 2.5: 41 The same rules apply as 2.4 except that you should follow linux-kernel 42 to track changes in API's. The final contact point for Linux 2.5 43 submissions is Linus Torvalds <torvalds@osdl.org>. 44 45What Criteria Determine Acceptance 46---------------------------------- 47 48Licensing: The code must be released to us under the 49 GNU General Public License. We don't insist on any kind 50 of exclusively GPL licensing, and if you wish the driver 51 to be useful to other communities such as BSD you may well 52 wish to release under multiple licenses. 53 54Interfaces: If your driver uses existing interfaces and behaves like 55 other drivers in the same class it will be much more likely 56 to be accepted than if it invents gratuitous new ones. 57 If you need to implement a common API over Linux and NT 58 drivers do it in userspace. 59 60Code: Please use the Linux style of code formatting as documented 61 in Documentation/CodingStyle. If you have sections of code 62 that need to be in other formats, for example because they 63 are shared with a windows driver kit and you want to 64 maintain them just once seperate them out nicely and note 65 this fact. 66 67Portability: Pointers are not always 32bits, not all computers are little 68 endian, people do not all have floating point and you 69 shouldn't use inline x86 assembler in your driver without 70 careful thought. Pure x86 drivers generally are not popular. 71 If you only have x86 hardware it is hard to test portability 72 but it is easy to make sure the code can easily be made 73 portable. 74 75Clarity: It helps if anyone can see how to fix the driver. It helps 76 you because you get patches not bug reports. If you submit a 77 driver that intentionally obfuscates how the hardware works 78 it will go in the bitbucket. 79 80Control: In general if there is active maintainance of a driver by 81 the author then patches will be redirected to them unless 82 they are totally obvious and without need of checking. 83 If you want to be the contact and update point for the 84 driver it is a good idea to state this in the comments, 85 and include an entry in MAINTAINERS for your driver. 86 87What Criteria Do Not Determine Acceptance 88----------------------------------------- 89 90Vendor: Being the hardware vendor and maintaining the driver is 91 often a good thing. If there is a stable working driver from 92 other people already in the tree don't expect 'we are the 93 vendor' to get your driver chosen. Ideally work with the 94 existing driver author to build a single perfect driver. 95 96Author: It doesn't matter if a large Linux company wrote the driver, 97 or you did. Nobody has any special access to the kernel 98 tree. Anyone who tells you otherwise isn't telling the 99 whole story. 100 101 102Resources 103--------- 104 105Linux kernel master tree: 106 ftp.??.kernel.org:/pub/linux/kernel/... 107 ?? == your country code, such as "us", "uk", "fr", etc. 108 109Linux kernel mailing list: 110 linux-kernel@vger.kernel.org 111 [mail majordomo@vger.kernel.org to subscribe] 112 113Kernel traffic: 114 Weekly summary of kernel list activity (much easier to read) 115 [http://kt.zork.net/kernel-traffic] 116 117Linux USB project: 118 http://sourceforge.net/projects/linux-usb/ 119 120