diff options
Diffstat (limited to 'Documentation/usb/gadget_multi.txt')
| -rw-r--r-- | Documentation/usb/gadget_multi.txt | 150 |
1 files changed, 0 insertions, 150 deletions
diff --git a/Documentation/usb/gadget_multi.txt b/Documentation/usb/gadget_multi.txt deleted file mode 100644 index 80f4ef0eb75..00000000000 --- a/Documentation/usb/gadget_multi.txt +++ /dev/null @@ -1,150 +0,0 @@ - -*- org -*- - -* Overview - -The Multifunction Composite Gadget (or g_multi) is a composite gadget -that makes extensive use of the composite framework to provide -a... multifunction gadget. - -In it's standard configuration it provides a single USB configuration -with RNDIS[1] (that is Ethernet), USB CDC[2] ACM (that is serial) and -USB Mass Storage functions. - -A CDC ECM (Ethernet) function may be turned on via a Kconfig option -and RNDIS can be turned off. If they are both enabled the gadget will -have two configurations -- one with RNDIS and another with CDC ECM[3]. - -Please not that if you use non-standard configuration (that is enable -CDC ECM) you may need to change vendor and/or product ID. - -* Host drivers - -To make use of the gadget one needs to make it work on host side -- -without that there's no hope of achieving anything with the gadget. -As one might expect, things one need to do very from system to system. - -** Linux host drivers - -Since the gadget uses standard composite framework and appears as such -to Linux host it does not need any additional drivers on Linux host -side. All the functions are handled by respective drivers developed -for them. - -This is also true for two configuration set-up with RNDIS -configuration being the first one. Linux host will use the second -configuration with CDC ECM which should work better under Linux. - -** Windows host drivers - -For the gadget two work under Windows two conditions have to be met: - -*** Detecting as composite gadget - -First of all, Windows need to detect the gadget as an USB composite -gadget which on its own have some conditions[4]. If they are met, -Windows lets USB Generic Parent Driver[5] handle the device which then -tries to much drivers for each individual interface (sort of, don't -get into too many details). - -The good news is: you do not have to worry about most of the -conditions! - -The only thing to worry is that the gadget has to have a single -configuration so a dual RNDIS and CDC ECM gadget won't work unless you -create a proper INF -- and of course, if you do submit it! - -*** Installing drivers for each function - -The other, trickier thing is making Windows install drivers for each -individual function. - -For mass storage it is trivial since Windows detect it's an interface -implementing USB Mass Storage class and selects appropriate driver. - -Things are harder with RDNIS and CDC ACM. - -**** RNDIS - -To make Windows select RNDIS drivers for the first function in the -gadget, one needs to use the [[file:linux.inf]] file provided with this -document. It "attaches" Window's RNDIS driver to the first interface -of the gadget. - -Please note, that while testing we encountered some issues[6] when -RNDIS was not the first interface. You do not need to worry abut it -unless you are trying to develop your own gadget in which case watch -out for this bug. - -**** CDC ACM - -Similarly, [[file:linux-cdc-acm.inf]] is provided for CDC ACM. - -**** Customising the gadget - -If you intend to hack the g_multi gadget be advised that rearranging -functions will obviously change interface numbers for each of the -functionality. As an effect provided INFs won't work since they have -interface numbers hard-coded in them (it's not hard to change those -though[7]). - -This also means, that after experimenting with g_multi and changing -provided functions one should change gadget's vendor and/or product ID -so there will be no collision with other customised gadgets or the -original gadget. - -Failing to comply may cause brain damage after wondering for hours why -things don't work as intended before realising Windows have cached -some drivers information (changing USB port may sometimes help plus -you might try using USBDeview[8] to remove the phantom device). - -**** INF testing - -Provided INF files have been tested on Windows XP SP3, Windows Vista -and Windows 7, all 32-bit versions. It should work on 64-bit versions -as well. It most likely won't work on Windows prior to Windows XP -SP2. - -** Other systems - -At this moment, drivers for any other systems have not been tested. -Knowing how MacOS is based on BSD and BSD is an Open Source it is -believed that it should (read: "I have no idea whether it will") work -out-of-the-box. - -For more exotic systems I have even less to say... - -Any testing and drivers *are* *welcome*! - -* Authors - -This document has been written by Michal Nazarewicz -([[mailto:mina86@mina86.com]]). INF files have been hacked with -support of Marek Szyprowski ([[mailto:m.szyprowski@samsung.com]]) and -Xiaofan Chen ([[mailto:xiaofanc@gmail.com]]) basing on the MS RNDIS -template[9], Microchip's CDC ACM INF file and David Brownell's -([[mailto:dbrownell@users.sourceforge.net]]) original INF files. - -* Footnotes - -[1] Remote Network Driver Interface Specification, -[[http://msdn.microsoft.com/en-us/library/ee484414.aspx]]. - -[2] Communications Device Class Abstract Control Model, spec for this -and other USB classes can be found at -[[http://www.usb.org/developers/devclass_docs/]]. - -[3] CDC Ethernet Control Model. - -[4] [[http://msdn.microsoft.com/en-us/library/ff537109(v=VS.85).aspx]] - -[5] [[http://msdn.microsoft.com/en-us/library/ff539234(v=VS.85).aspx]] - -[6] To put it in some other nice words, Windows failed to respond to -any user input. - -[7] You may find [[http://www.cygnal.org/ubb/Forum9/HTML/001050.html]] -useful. - -[8] http://www.nirsoft.net/utils/usb_devices_view.html - -[9] [[http://msdn.microsoft.com/en-us/library/ff570620.aspx]] |