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diff --git a/Documentation/SubmittingDrivers b/Documentation/SubmittingDrivers new file mode 100644 index 000000000..31d372609 --- /dev/null +++ b/Documentation/SubmittingDrivers @@ -0,0 +1,163 @@ +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/ |