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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
| commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
| tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /Documentation/usb | |
| parent | Initial commit. (diff) | |
| download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip | |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Documentation/usb')
28 files changed, 6050 insertions, 0 deletions
diff --git a/Documentation/usb/CREDITS b/Documentation/usb/CREDITS new file mode 100644 index 000000000..67c59cdc9 --- /dev/null +++ b/Documentation/usb/CREDITS @@ -0,0 +1,175 @@ +Credits for the Simple Linux USB Driver: + +The following people have contributed to this code (in alphabetical +order by last name). I'm sure this list should be longer, its +difficult to maintain, add yourself with a patch if desired. + + Georg Acher <acher@informatik.tu-muenchen.de> + David Brownell <dbrownell@users.sourceforge.net> + Alan Cox <alan@lxorguk.ukuu.org.uk> + Randy Dunlap <randy.dunlap@intel.com> + Johannes Erdfelt <johannes@erdfelt.com> + Deti Fliegl <deti@fliegl.de> + ham <ham@unsuave.com> + Bradley M Keryan <keryan@andrew.cmu.edu> + Greg Kroah-Hartman <greg@kroah.com> + Pavel Machek <pavel@suse.cz> + Paul Mackerras <paulus@cs.anu.edu.au> + Petko Manlolov <petkan@dce.bg> + David E. Nelson <dnelson@jump.net> + Vojtech Pavlik <vojtech@suse.cz> + Bill Ryder <bryder@sgi.com> + Thomas Sailer <sailer@ife.ee.ethz.ch> + Gregory P. Smith <greg@electricrain.com> + Linus Torvalds <torvalds@linux-foundation.org> + Roman Weissgaerber <weissg@vienna.at> + <Kazuki.Yasumatsu@fujixerox.co.jp> + +Special thanks to: + + Inaky Perez Gonzalez <inaky@peloncho.fis.ucm.es> for starting the + Linux USB driver effort and writing much of the larger uusbd driver. + Much has been learned from that effort. + + The NetBSD & FreeBSD USB developers. For being on the Linux USB list + and offering suggestions and sharing implementation experiences. + +Additional thanks to the following companies and people for donations +of hardware, support, time and development (this is from the original +THANKS file in Inaky's driver): + + The following corporations have helped us in the development + of Linux USB / UUSBD: + + - 3Com GmbH for donating a ISDN Pro TA and supporting me + in technical questions and with test equipment. I'd never + expect such a great help. + + - USAR Systems provided us with one of their excellent USB + Evaluation Kits. It allows us to test the Linux-USB driver + for compliance with the latest USB specification. USAR + Systems recognized the importance of an up-to-date open + Operating System and supports this project with + Hardware. Thanks!. + + - Thanks to Intel Corporation for their precious help. + + - We teamed up with Cherry to make Linux the first OS with + built-in USB support. Cherry is one of the biggest keyboard + makers in the world. + + - CMD Technology, Inc. sponsored us kindly donating a CSA-6700 + PCI-to-USB Controller Board to test the OHCI implementation. + + - Due to their support to us, Keytronic can be sure that they + will sell keyboards to some of the 3 million (at least) + Linux users. + + - Many thanks to ing büro h doran [http://www.ibhdoran.com]! + It was almost impossible to get a PC backplate USB connector + for the motherboard here at Europe (mine, home-made, was + quite lousy :). Now I know where to acquire nice USB stuff! + + - Genius Germany donated a USB mouse to test the mouse boot + protocol. They've also donated a F-23 digital joystick and a + NetMouse Pro. Thanks! + + - AVM GmbH Berlin is supporting the development of the Linux + USB driver for the AVM ISDN Controller B1 USB. AVM is a + leading manufacturer for active and passive ISDN Controllers + and CAPI 2.0-based software. The active design of the AVM B1 + is open for all OS platforms, including Linux. + + - Thanks to Y-E Data, Inc. for donating their FlashBuster-U + USB Floppy Disk Drive, so we could test the bulk transfer + code. + + - Many thanks to Logitech for contributing a three axis USB + mouse. + + Logitech designs, manufactures and markets + Human Interface Devices, having a long history and + experience in making devices such as keyboards, mice, + trackballs, cameras, loudspeakers and control devices for + gaming and professional use. + + Being a recognized vendor and seller for all these devices, + they have donated USB mice, a joystick and a scanner, as a + way to acknowledge the importance of Linux and to allow + Logitech customers to enjoy support in their favorite + operating systems and all Linux users to use Logitech and + other USB hardware. + + Logitech is official sponsor of the Linux Conference on + Feb. 11th 1999 in Vienna, where we'll will present the + current state of the Linux USB effort. + + - CATC has provided means to uncover dark corners of the UHCI + inner workings with a USB Inspector. + + - Thanks to Entrega for providing PCI to USB cards, hubs and + converter products for development. + + - Thanks to ConnectTech for providing a WhiteHEAT usb to + serial converter, and the documentation for the device to + allow a driver to be written. + + - Thanks to ADMtek for providing Pegasus and Pegasus II + evaluation boards, specs and valuable advices during + the driver development. + + And thanks go to (hey! in no particular order :) + + - Oren Tirosh <orenti@hishome.net>, for standing so patiently + all my doubts'bout USB and giving lots of cool ideas. + + - Jochen Karrer <karrer@wpfd25.physik.uni-wuerzburg.de>, for + pointing out mortal bugs and giving advice. + + - Edmund Humemberger <ed@atnet.at>, for it's great work on + public relationships and general management stuff for the + Linux-USB effort. + + - Alberto Menegazzi <flash@flash.iol.it> is starting the + documentation for the UUSBD. Go for it! + + - Ric Klaren <ia_ric@cs.utwente.nl> for doing nice + introductory documents (competing with Alberto's :). + + - Christian Groessler <cpg@aladdin.de>, for it's help on those + itchy bits ... :) + + - Paul MacKerras for polishing OHCI and pushing me harder for + the iMac support, giving improvements and enhancements. + + - Fernando Herrera <fherrera@eurielec.etsit.upm.es> has taken + charge of composing, maintaining and feeding the + long-awaited, unique and marvelous UUSBD FAQ! Tadaaaa!!! + + - Rasca Gmelch <thron@gmx.de> has revived the raw driver and + pointed bugs, as well as started the uusbd-utils package. + + - Peter Dettori <dettori@ozy.dec.com> is uncovering bugs like + crazy, as well as making cool suggestions, great :) + + - All the Free Software and Linux community, the FSF & the GNU + project, the MIT X consortium, the TeX people ... everyone! + You know who you are! + + - Big thanks to Richard Stallman for creating Emacs! + + - The people at the linux-usb mailing list, for reading so + many messages :) Ok, no more kidding; for all your advises! + + - All the people at the USB Implementors Forum for their + help and assistance. + + - Nathan Myers <ncm@cantrip.org>, for his advice! (hope you + liked Cibeles' party). + + - Linus Torvalds, for starting, developing and managing Linux. + + - Mike Smith, Craig Keithley, Thierry Giron and Janet Schank + for convincing me USB Standard hubs are not that standard + and that's good to allow for vendor specific quirks on the + standard hub driver. diff --git a/Documentation/usb/acm.rst b/Documentation/usb/acm.rst new file mode 100644 index 000000000..e8bda98e9 --- /dev/null +++ b/Documentation/usb/acm.rst @@ -0,0 +1,132 @@ +====================== +Linux ACM driver v0.16 +====================== + +Copyright (c) 1999 Vojtech Pavlik <vojtech@suse.cz> + +Sponsored by SuSE + +0. Disclaimer +~~~~~~~~~~~~~ +This program is free software; you can redistribute it and/or modify it +under the terms of the GNU General Public License as published by the Free +Software Foundation; either version 2 of the License, or (at your option) +any later version. + +This program is distributed in the hope that it will be useful, but +WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY +or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for +more details. + +You should have received a copy of the GNU General Public License along +with this program; if not, write to the Free Software Foundation, Inc., 59 +Temple Place, Suite 330, Boston, MA 02111-1307 USA + +Should you need to contact me, the author, you can do so either by e-mail - +mail your message to <vojtech@suse.cz>, or by paper mail: Vojtech Pavlik, +Ucitelska 1576, Prague 8, 182 00 Czech Republic + +For your convenience, the GNU General Public License version 2 is included +in the package: See the file COPYING. + +1. Usage +~~~~~~~~ +The drivers/usb/class/cdc-acm.c drivers works with USB modems and USB ISDN terminal +adapters that conform to the Universal Serial Bus Communication Device Class +Abstract Control Model (USB CDC ACM) specification. + +Many modems do, here is a list of those I know of: + + - 3Com OfficeConnect 56k + - 3Com Voice FaxModem Pro + - 3Com Sportster + - MultiTech MultiModem 56k + - Zoom 2986L FaxModem + - Compaq 56k FaxModem + - ELSA Microlink 56k + +I know of one ISDN TA that does work with the acm driver: + + - 3Com USR ISDN Pro TA + +Some cell phones also connect via USB. I know the following phones work: + + - SonyEricsson K800i + +Unfortunately many modems and most ISDN TAs use proprietary interfaces and +thus won't work with this drivers. Check for ACM compliance before buying. + +To use the modems you need these modules loaded:: + + usbcore.ko + uhci-hcd.ko ohci-hcd.ko or ehci-hcd.ko + cdc-acm.ko + +After that, the modem[s] should be accessible. You should be able to use +minicom, ppp and mgetty with them. + +2. Verifying that it works +~~~~~~~~~~~~~~~~~~~~~~~~~~ + +The first step would be to check /sys/kernel/debug/usb/devices, it should look +like this:: + + T: Bus=01 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#= 1 Spd=12 MxCh= 2 + B: Alloc= 0/900 us ( 0%), #Int= 0, #Iso= 0 + D: Ver= 1.00 Cls=09(hub ) Sub=00 Prot=00 MxPS= 8 #Cfgs= 1 + P: Vendor=0000 ProdID=0000 Rev= 0.00 + S: Product=USB UHCI Root Hub + S: SerialNumber=6800 + C:* #Ifs= 1 Cfg#= 1 Atr=40 MxPwr= 0mA + I: If#= 0 Alt= 0 #EPs= 1 Cls=09(hub ) Sub=00 Prot=00 Driver=hub + E: Ad=81(I) Atr=03(Int.) MxPS= 8 Ivl=255ms + T: Bus=01 Lev=01 Prnt=01 Port=01 Cnt=01 Dev#= 2 Spd=12 MxCh= 0 + D: Ver= 1.00 Cls=02(comm.) Sub=00 Prot=00 MxPS= 8 #Cfgs= 2 + P: Vendor=04c1 ProdID=008f Rev= 2.07 + S: Manufacturer=3Com Inc. + S: Product=3Com U.S. Robotics Pro ISDN TA + S: SerialNumber=UFT53A49BVT7 + C: #Ifs= 1 Cfg#= 1 Atr=60 MxPwr= 0mA + I: If#= 0 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=ff Driver=acm + E: Ad=85(I) Atr=02(Bulk) MxPS= 64 Ivl= 0ms + E: Ad=04(O) Atr=02(Bulk) MxPS= 64 Ivl= 0ms + E: Ad=81(I) Atr=03(Int.) MxPS= 16 Ivl=128ms + C:* #Ifs= 2 Cfg#= 2 Atr=60 MxPwr= 0mA + I: If#= 0 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=02 Prot=01 Driver=acm + E: Ad=81(I) Atr=03(Int.) MxPS= 16 Ivl=128ms + I: If#= 1 Alt= 0 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=acm + E: Ad=85(I) Atr=02(Bulk) MxPS= 64 Ivl= 0ms + E: Ad=04(O) Atr=02(Bulk) MxPS= 64 Ivl= 0ms + +The presence of these three lines (and the Cls= 'comm' and 'data' classes) +is important, it means it's an ACM device. The Driver=acm means the acm +driver is used for the device. If you see only Cls=ff(vend.) then you're out +of luck, you have a device with vendor specific-interface:: + + D: Ver= 1.00 Cls=02(comm.) Sub=00 Prot=00 MxPS= 8 #Cfgs= 2 + I: If#= 0 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=02 Prot=01 Driver=acm + I: If#= 1 Alt= 0 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=acm + +In the system log you should see:: + + usb.c: USB new device connect, assigned device number 2 + usb.c: kmalloc IF c7691fa0, numif 1 + usb.c: kmalloc IF c7b5f3e0, numif 2 + usb.c: skipped 4 class/vendor specific interface descriptors + usb.c: new device strings: Mfr=1, Product=2, SerialNumber=3 + usb.c: USB device number 2 default language ID 0x409 + Manufacturer: 3Com Inc. + Product: 3Com U.S. Robotics Pro ISDN TA + SerialNumber: UFT53A49BVT7 + acm.c: probing config 1 + acm.c: probing config 2 + ttyACM0: USB ACM device + acm.c: acm_control_msg: rq: 0x22 val: 0x0 len: 0x0 result: 0 + acm.c: acm_control_msg: rq: 0x20 val: 0x0 len: 0x7 result: 7 + usb.c: acm driver claimed interface c7b5f3e0 + usb.c: acm driver claimed interface c7b5f3f8 + usb.c: acm driver claimed interface c7691fa0 + +If all this seems to be OK, fire up minicom and set it to talk to the ttyACM +device and try typing 'at'. If it responds with 'OK', then everything is +working. diff --git a/Documentation/usb/authorization.rst b/Documentation/usb/authorization.rst new file mode 100644 index 000000000..9e53909d0 --- /dev/null +++ b/Documentation/usb/authorization.rst @@ -0,0 +1,132 @@ +============================================================== +Authorizing (or not) your USB devices to connect to the system +============================================================== + +Copyright (C) 2007 Inaky Perez-Gonzalez <inaky@linux.intel.com> Intel Corporation + +This feature allows you to control if a USB device can be used (or +not) in a system. This feature will allow you to implement a lock-down +of USB devices, fully controlled by user space. + +As of now, when a USB device is connected it is configured and +its interfaces are immediately made available to the users. With this +modification, only if root authorizes the device to be configured will +then it be possible to use it. + +Usage +===== + +Authorize a device to connect:: + + $ echo 1 > /sys/bus/usb/devices/DEVICE/authorized + +De-authorize a device:: + + $ echo 0 > /sys/bus/usb/devices/DEVICE/authorized + +Set new devices connected to hostX to be deauthorized by default (ie: +lock down):: + + $ echo 0 > /sys/bus/usb/devices/usbX/authorized_default + +Remove the lock down:: + + $ echo 1 > /sys/bus/usb/devices/usbX/authorized_default + +By default, Wired USB devices are authorized by default to +connect. Wireless USB hosts deauthorize by default all new connected +devices (this is so because we need to do an authentication phase +before authorizing). Writing "2" to the authorized_default attribute +causes kernel to only authorize by default devices connected to internal +USB ports. + + +Example system lockdown (lame) +------------------------------ + +Imagine you want to implement a lockdown so only devices of type XYZ +can be connected (for example, it is a kiosk machine with a visible +USB port):: + + boot up + rc.local -> + + for host in /sys/bus/usb/devices/usb* + do + echo 0 > $host/authorized_default + done + +Hookup an script to udev, for new USB devices:: + + if device_is_my_type $DEV + then + echo 1 > $device_path/authorized + done + + +Now, device_is_my_type() is where the juice for a lockdown is. Just +checking if the class, type and protocol match something is the worse +security verification you can make (or the best, for someone willing +to break it). If you need something secure, use crypto and Certificate +Authentication or stuff like that. Something simple for an storage key +could be:: + + function device_is_my_type() + { + echo 1 > authorized # temporarily authorize it + # FIXME: make sure none can mount it + mount DEVICENODE /mntpoint + sum=$(md5sum /mntpoint/.signature) + if [ $sum = $(cat /etc/lockdown/keysum) ] + then + echo "We are good, connected" + umount /mntpoint + # Other stuff so others can use it + else + echo 0 > authorized + fi + } + + +Of course, this is lame, you'd want to do a real certificate +verification stuff with PKI, so you don't depend on a shared secret, +etc, but you get the idea. Anybody with access to a device gadget kit +can fake descriptors and device info. Don't trust that. You are +welcome. + + +Interface authorization +----------------------- + +There is a similar approach to allow or deny specific USB interfaces. +That allows to block only a subset of an USB device. + +Authorize an interface:: + + $ echo 1 > /sys/bus/usb/devices/INTERFACE/authorized + +Deauthorize an interface:: + + $ echo 0 > /sys/bus/usb/devices/INTERFACE/authorized + +The default value for new interfaces +on a particular USB bus can be changed, too. + +Allow interfaces per default:: + + $ echo 1 > /sys/bus/usb/devices/usbX/interface_authorized_default + +Deny interfaces per default:: + + $ echo 0 > /sys/bus/usb/devices/usbX/interface_authorized_default + +Per default the interface_authorized_default bit is 1. +So all interfaces would authorized per default. + +Note: + If a deauthorized interface will be authorized so the driver probing must + be triggered manually by writing INTERFACE to /sys/bus/usb/drivers_probe + +For drivers that need multiple interfaces all needed interfaces should be +authorized first. After that the drivers should be probed. +This avoids side effects. diff --git a/Documentation/usb/chipidea.rst b/Documentation/usb/chipidea.rst new file mode 100644 index 000000000..68473abe2 --- /dev/null +++ b/Documentation/usb/chipidea.rst @@ -0,0 +1,133 @@ +============================================== +ChipIdea Highspeed Dual Role Controller Driver +============================================== + +1. How to test OTG FSM(HNP and SRP) +----------------------------------- + +To show how to demo OTG HNP and SRP functions via sys input files +with 2 Freescale i.MX6Q sabre SD boards. + +1.1 How to enable OTG FSM +------------------------- + +1.1.1 Select CONFIG_USB_OTG_FSM in menuconfig, rebuild kernel +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Image and modules. If you want to check some internal +variables for otg fsm, mount debugfs, there are 2 files +which can show otg fsm variables and some controller registers value:: + + cat /sys/kernel/debug/ci_hdrc.0/otg + cat /sys/kernel/debug/ci_hdrc.0/registers + +1.1.2 Add below entries in your dts file for your controller node +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +:: + + otg-rev = <0x0200>; + adp-disable; + +1.2 Test operations +------------------- + +1) Power up 2 Freescale i.MX6Q sabre SD boards with gadget class driver loaded + (e.g. g_mass_storage). + +2) Connect 2 boards with usb cable with one end is micro A plug, the other end + is micro B plug. + + The A-device(with micro A plug inserted) should enumerate B-device. + +3) Role switch + + On B-device:: + + echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/b_bus_req + + B-device should take host role and enumerate A-device. + +4) A-device switch back to host. + + On B-device:: + + echo 0 > /sys/bus/platform/devices/ci_hdrc.0/inputs/b_bus_req + + or, by introducing HNP polling, B-Host can know when A-peripheral wish + to be host role, so this role switch also can be trigged in A-peripheral + side by answering the polling from B-Host, this can be done on A-device:: + + echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/a_bus_req + + A-device should switch back to host and enumerate B-device. + +5) Remove B-device(unplug micro B plug) and insert again in 10 seconds, + A-device should enumerate B-device again. + +6) Remove B-device(unplug micro B plug) and insert again after 10 seconds, + A-device should NOT enumerate B-device. + + if A-device wants to use bus: + + On A-device:: + + echo 0 > /sys/bus/platform/devices/ci_hdrc.0/inputs/a_bus_drop + echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/a_bus_req + + if B-device wants to use bus: + + On B-device:: + + echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/b_bus_req + +7) A-device power down the bus. + + On A-device:: + + echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/a_bus_drop + + A-device should disconnect with B-device and power down the bus. + +8) B-device does data pulse for SRP. + + On B-device:: + + echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/b_bus_req + + A-device should resume usb bus and enumerate B-device. + +1.3 Reference document +---------------------- +"On-The-Go and Embedded Host Supplement to the USB Revision 2.0 Specification +July 27, 2012 Revision 2.0 version 1.1a" + +2. How to enable USB as system wakeup source +-------------------------------------------- +Below is the example for how to enable USB as system wakeup source +at imx6 platform. + +2.1 Enable core's wakeup:: + + echo enabled > /sys/bus/platform/devices/ci_hdrc.0/power/wakeup + +2.2 Enable glue layer's wakeup:: + + echo enabled > /sys/bus/platform/devices/2184000.usb/power/wakeup + +2.3 Enable PHY's wakeup (optional):: + + echo enabled > /sys/bus/platform/devices/20c9000.usbphy/power/wakeup + +2.4 Enable roothub's wakeup:: + + echo enabled > /sys/bus/usb/devices/usb1/power/wakeup + +2.5 Enable related device's wakeup:: + + echo enabled > /sys/bus/usb/devices/1-1/power/wakeup + +If the system has only one usb port, and you want usb wakeup at this port, you +can use below script to enable usb wakeup:: + + for i in $(find /sys -name wakeup | grep usb);do echo enabled > $i;done; diff --git a/Documentation/usb/dwc3.rst b/Documentation/usb/dwc3.rst new file mode 100644 index 000000000..f94a7ba16 --- /dev/null +++ b/Documentation/usb/dwc3.rst @@ -0,0 +1,53 @@ +=========== +DWC3 driver +=========== + + +TODO +~~~~ + +Please pick something while reading :) + +- Convert interrupt handler to per-ep-thread-irq + + As it turns out some DWC3-commands ~1ms to complete. Currently we spin + until the command completes which is bad. + + Implementation idea: + + - dwc core implements a demultiplexing irq chip for interrupts per + endpoint. The interrupt numbers are allocated during probe and belong + to the device. If MSI provides per-endpoint interrupt this dummy + interrupt chip can be replaced with "real" interrupts. + - interrupts are requested / allocated on usb_ep_enable() and removed on + usb_ep_disable(). Worst case are 32 interrupts, the lower limit is two + for ep0/1. + - dwc3_send_gadget_ep_cmd() will sleep in wait_for_completion_timeout() + until the command completes. + - the interrupt handler is split into the following pieces: + + - primary handler of the device + goes through every event and calls generic_handle_irq() for event + it. On return from generic_handle_irq() in acknowledges the event + counter so interrupt goes away (eventually). + + - threaded handler of the device + none + + - primary handler of the EP-interrupt + reads the event and tries to process it. Everything that requires + sleeping is handed over to the Thread. The event is saved in an + per-endpoint data-structure. + We probably have to pay attention not to process events once we + handed something to thread so we don't process event X prio Y + where X > Y. + + - threaded handler of the EP-interrupt + handles the remaining EP work which might sleep such as waiting + for command completion. + + Latency: + + There should be no increase in latency since the interrupt-thread has a + high priority and will be run before an average task in user land + (except the user changed priorities). diff --git a/Documentation/usb/ehci.rst b/Documentation/usb/ehci.rst new file mode 100644 index 000000000..761905019 --- /dev/null +++ b/Documentation/usb/ehci.rst @@ -0,0 +1,230 @@ +=========== +EHCI driver +=========== + +27-Dec-2002 + +The EHCI driver is used to talk to high speed USB 2.0 devices using +USB 2.0-capable host controller hardware. The USB 2.0 standard is +compatible with the USB 1.1 standard. It defines three transfer speeds: + + - "High Speed" 480 Mbit/sec (60 MByte/sec) + - "Full Speed" 12 Mbit/sec (1.5 MByte/sec) + - "Low Speed" 1.5 Mbit/sec + +USB 1.1 only addressed full speed and low speed. High speed devices +can be used on USB 1.1 systems, but they slow down to USB 1.1 speeds. + +USB 1.1 devices may also be used on USB 2.0 systems. When plugged +into an EHCI controller, they are given to a USB 1.1 "companion" +controller, which is a OHCI or UHCI controller as normally used with +such devices. When USB 1.1 devices plug into USB 2.0 hubs, they +interact with the EHCI controller through a "Transaction Translator" +(TT) in the hub, which turns low or full speed transactions into +high speed "split transactions" that don't waste transfer bandwidth. + +At this writing, this driver has been seen to work with implementations +of EHCI from (in alphabetical order): Intel, NEC, Philips, and VIA. +Other EHCI implementations are becoming available from other vendors; +you should expect this driver to work with them too. + +While usb-storage devices have been available since mid-2001 (working +quite speedily on the 2.4 version of this driver), hubs have only +been available since late 2001, and other kinds of high speed devices +appear to be on hold until more systems come with USB 2.0 built-in. +Such new systems have been available since early 2002, and became much +more typical in the second half of 2002. + +Note that USB 2.0 support involves more than just EHCI. It requires +other changes to the Linux-USB core APIs, including the hub driver, +but those changes haven't needed to really change the basic "usbcore" +APIs exposed to USB device drivers. + +- David Brownell + <dbrownell@users.sourceforge.net> + + +Functionality +============= + +This driver is regularly tested on x86 hardware, and has also been +used on PPC hardware so big/little endianness issues should be gone. +It's believed to do all the right PCI magic so that I/O works even on +systems with interesting DMA mapping issues. + +Transfer Types +-------------- + +At this writing the driver should comfortably handle all control, bulk, +and interrupt transfers, including requests to USB 1.1 devices through +transaction translators (TTs) in USB 2.0 hubs. But you may find bugs. + +High Speed Isochronous (ISO) transfer support is also functional, but +at this writing no Linux drivers have been using that support. + +Full Speed Isochronous transfer support, through transaction translators, +is not yet available. Note that split transaction support for ISO +transfers can't share much code with the code for high speed ISO transfers, +since EHCI represents these with a different data structure. So for now, +most USB audio and video devices can't be connected to high speed buses. + +Driver Behavior +--------------- + +Transfers of all types can be queued. This means that control transfers +from a driver on one interface (or through usbfs) won't interfere with +ones from another driver, and that interrupt transfers can use periods +of one frame without risking data loss due to interrupt processing costs. + +The EHCI root hub code hands off USB 1.1 devices to its companion +controller. This driver doesn't need to know anything about those +drivers; a OHCI or UHCI driver that works already doesn't need to change +just because the EHCI driver is also present. + +There are some issues with power management; suspend/resume doesn't +behave quite right at the moment. + +Also, some shortcuts have been taken with the scheduling periodic +transactions (interrupt and isochronous transfers). These place some +limits on the number of periodic transactions that can be scheduled, +and prevent use of polling intervals of less than one frame. + + +Use by +====== + +Assuming you have an EHCI controller (on a PCI card or motherboard) +and have compiled this driver as a module, load this like:: + + # modprobe ehci-hcd + +and remove it by:: + + # rmmod ehci-hcd + +You should also have a driver for a "companion controller", such as +"ohci-hcd" or "uhci-hcd". In case of any trouble with the EHCI driver, +remove its module and then the driver for that companion controller will +take over (at lower speed) all the devices that were previously handled +by the EHCI driver. + +Module parameters (pass to "modprobe") include: + + log2_irq_thresh (default 0): + Log2 of default interrupt delay, in microframes. The default + value is 0, indicating 1 microframe (125 usec). Maximum value + is 6, indicating 2^6 = 64 microframes. This controls how often + the EHCI controller can issue interrupts. + +If you're using this driver on a 2.5 kernel, and you've enabled USB +debugging support, you'll see three files in the "sysfs" directory for +any EHCI controller: + + "async" + dumps the asynchronous schedule, used for control + and bulk transfers. Shows each active qh and the qtds + pending, usually one qtd per urb. (Look at it with + usb-storage doing disk I/O; watch the request queues!) + "periodic" + dumps the periodic schedule, used for interrupt + and isochronous transfers. Doesn't show qtds. + "registers" + show controller register state, and + +The contents of those files can help identify driver problems. + + +Device drivers shouldn't care whether they're running over EHCI or not, +but they may want to check for "usb_device->speed == USB_SPEED_HIGH". +High speed devices can do things that full speed (or low speed) ones +can't, such as "high bandwidth" periodic (interrupt or ISO) transfers. +Also, some values in device descriptors (such as polling intervals for +periodic transfers) use different encodings when operating at high speed. + +However, do make a point of testing device drivers through USB 2.0 hubs. +Those hubs report some failures, such as disconnections, differently when +transaction translators are in use; some drivers have been seen to behave +badly when they see different faults than OHCI or UHCI report. + + +Performance +=========== + +USB 2.0 throughput is gated by two main factors: how fast the host +controller can process requests, and how fast devices can respond to +them. The 480 Mbit/sec "raw transfer rate" is obeyed by all devices, +but aggregate throughput is also affected by issues like delays between +individual high speed packets, driver intelligence, and of course the +overall system load. Latency is also a performance concern. + +Bulk transfers are most often used where throughput is an issue. It's +good to keep in mind that bulk transfers are always in 512 byte packets, +and at most 13 of those fit into one USB 2.0 microframe. Eight USB 2.0 +microframes fit in a USB 1.1 frame; a microframe is 1 msec/8 = 125 usec. + +So more than 50 MByte/sec is available for bulk transfers, when both +hardware and device driver software allow it. Periodic transfer modes +(isochronous and interrupt) allow the larger packet sizes which let you +approach the quoted 480 MBit/sec transfer rate. + +Hardware Performance +-------------------- + +At this writing, individual USB 2.0 devices tend to max out at around +20 MByte/sec transfer rates. This is of course subject to change; +and some devices now go faster, while others go slower. + +The first NEC implementation of EHCI seems to have a hardware bottleneck +at around 28 MByte/sec aggregate transfer rate. While this is clearly +enough for a single device at 20 MByte/sec, putting three such devices +onto one bus does not get you 60 MByte/sec. The issue appears to be +that the controller hardware won't do concurrent USB and PCI access, +so that it's only trying six (or maybe seven) USB transactions each +microframe rather than thirteen. (Seems like a reasonable trade off +for a product that beat all the others to market by over a year!) + +It's expected that newer implementations will better this, throwing +more silicon real estate at the problem so that new motherboard chip +sets will get closer to that 60 MByte/sec target. That includes an +updated implementation from NEC, as well as other vendors' silicon. + +There's a minimum latency of one microframe (125 usec) for the host +to receive interrupts from the EHCI controller indicating completion +of requests. That latency is tunable; there's a module option. By +default ehci-hcd driver uses the minimum latency, which means that if +you issue a control or bulk request you can often expect to learn that +it completed in less than 250 usec (depending on transfer size). + +Software Performance +-------------------- + +To get even 20 MByte/sec transfer rates, Linux-USB device drivers will +need to keep the EHCI queue full. That means issuing large requests, +or using bulk queuing if a series of small requests needs to be issued. +When drivers don't do that, their performance results will show it. + +In typical situations, a usb_bulk_msg() loop writing out 4 KB chunks is +going to waste more than half the USB 2.0 bandwidth. Delays between the +I/O completion and the driver issuing the next request will take longer +than the I/O. If that same loop used 16 KB chunks, it'd be better; a +sequence of 128 KB chunks would waste a lot less. + +But rather than depending on such large I/O buffers to make synchronous +I/O be efficient, it's better to just queue up several (bulk) requests +to the HC, and wait for them all to complete (or be canceled on error). +Such URB queuing should work with all the USB 1.1 HC drivers too. + +In the Linux 2.5 kernels, new usb_sg_*() api calls have been defined; they +queue all the buffers from a scatterlist. They also use scatterlist DMA +mapping (which might apply an IOMMU) and IRQ reduction, all of which will +help make high speed transfers run as fast as they can. + + +TBD: + Interrupt and ISO transfer performance issues. Those periodic + transfers are fully scheduled, so the main issue is likely to be how + to trigger "high bandwidth" modes. + +TBD: + More than standard 80% periodic bandwidth allocation is possible + through sysfs uframe_periodic_max parameter. Describe that. diff --git a/Documentation/usb/functionfs.rst b/Documentation/usb/functionfs.rst new file mode 100644 index 000000000..7fdc6d840 --- /dev/null +++ b/Documentation/usb/functionfs.rst @@ -0,0 +1,68 @@ +==================== +How FunctionFS works +==================== + +From kernel point of view it is just a composite function with some +unique behaviour. It may be added to an USB configuration only after +the user space driver has registered by writing descriptors and +strings (the user space program has to provide the same information +that kernel level composite functions provide when they are added to +the configuration). + +This in particular means that the composite initialisation functions +may not be in init section (ie. may not use the __init tag). + +From user space point of view it is a file system which when +mounted provides an "ep0" file. User space driver need to +write descriptors and strings to that file. It does not need +to worry about endpoints, interfaces or strings numbers but +simply provide descriptors such as if the function was the +only one (endpoints and strings numbers starting from one and +interface numbers starting from zero). The FunctionFS changes +them as needed also handling situation when numbers differ in +different configurations. + +When descriptors and strings are written "ep#" files appear +(one for each declared endpoint) which handle communication on +a single endpoint. Again, FunctionFS takes care of the real +numbers and changing of the configuration (which means that +"ep1" file may be really mapped to (say) endpoint 3 (and when +configuration changes to (say) endpoint 2)). "ep0" is used +for receiving events and handling setup requests. + +When all files are closed the function disables itself. + +What I also want to mention is that the FunctionFS is designed in such +a way that it is possible to mount it several times so in the end +a gadget could use several FunctionFS functions. The idea is that +each FunctionFS instance is identified by the device name used +when mounting. + +One can imagine a gadget that has an Ethernet, MTP and HID interfaces +where the last two are implemented via FunctionFS. On user space +level it would look like this:: + + $ insmod g_ffs.ko idVendor=<ID> iSerialNumber=<string> functions=mtp,hid + $ mkdir /dev/ffs-mtp && mount -t functionfs mtp /dev/ffs-mtp + $ ( cd /dev/ffs-mtp && mtp-daemon ) & + $ mkdir /dev/ffs-hid && mount -t functionfs hid /dev/ffs-hid + $ ( cd /dev/ffs-hid && hid-daemon ) & + +On kernel level the gadget checks ffs_data->dev_name to identify +whether it's FunctionFS designed for MTP ("mtp") or HID ("hid"). + +If no "functions" module parameters is supplied, the driver accepts +just one function with any name. + +When "functions" module parameter is supplied, only functions +with listed names are accepted. In particular, if the "functions" +parameter's value is just a one-element list, then the behaviour +is similar to when there is no "functions" at all; however, +only a function with the specified name is accepted. + +The gadget is registered only after all the declared function +filesystems have been mounted and USB descriptors of all functions +have been written to their ep0's. + +Conversely, the gadget is unregistered after the first USB function +closes its endpoints. diff --git a/Documentation/usb/gadget-testing.rst b/Documentation/usb/gadget-testing.rst new file mode 100644 index 000000000..2278c9ffb --- /dev/null +++ b/Documentation/usb/gadget-testing.rst @@ -0,0 +1,967 @@ +============== +Gadget Testing +============== + +This file summarizes information on basic testing of USB functions +provided by gadgets. + +.. contents + + 1. ACM function + 2. ECM function + 3. ECM subset function + 4. EEM function + 5. FFS function + 6. HID function + 7. LOOPBACK function + 8. MASS STORAGE function + 9. MIDI function + 10. NCM function + 11. OBEX function + 12. PHONET function + 13. RNDIS function + 14. SERIAL function + 15. SOURCESINK function + 16. UAC1 function (legacy implementation) + 17. UAC2 function + 18. UVC function + 19. PRINTER function + 20. UAC1 function (new API) + + +1. ACM function +=============== + +The function is provided by usb_f_acm.ko module. + +Function-specific configfs interface +------------------------------------ + +The function name to use when creating the function directory is "acm". +The ACM function provides just one attribute in its function directory: + + port_num + +The attribute is read-only. + +There can be at most 4 ACM/generic serial/OBEX ports in the system. + + +Testing the ACM function +------------------------ + +On the host:: + + cat > /dev/ttyACM<X> + +On the device:: + + cat /dev/ttyGS<Y> + +then the other way round + +On the device:: + + cat > /dev/ttyGS<Y> + +On the host:: + + cat /dev/ttyACM<X> + +2. ECM function +=============== + +The function is provided by usb_f_ecm.ko module. + +Function-specific configfs interface +------------------------------------ + +The function name to use when creating the function directory is "ecm". +The ECM function provides these attributes in its function directory: + + =============== ================================================== + ifname network device interface name associated with this + function instance + qmult queue length multiplier for high and super speed + host_addr MAC address of host's end of this + Ethernet over USB link + dev_addr MAC address of device's end of this + Ethernet over USB link + =============== ================================================== + +and after creating the functions/ecm.<instance name> they contain default +values: qmult is 5, dev_addr and host_addr are randomly selected. +The ifname can be written to if the function is not bound. A write must be an +interface pattern such as "usb%d", which will cause the net core to choose the +next free usbX interface. By default, it is set to "usb%d". + +Testing the ECM function +------------------------ + +Configure IP addresses of the device and the host. Then: + +On the device:: + + ping <host's IP> + +On the host:: + + ping <device's IP> + +3. ECM subset function +====================== + +The function is provided by usb_f_ecm_subset.ko module. + +Function-specific configfs interface +------------------------------------ + +The function name to use when creating the function directory is "geth". +The ECM subset function provides these attributes in its function directory: + + =============== ================================================== + ifname network device interface name associated with this + function instance + qmult queue length multiplier for high and super speed + host_addr MAC address of host's end of this + Ethernet over USB link + dev_addr MAC address of device's end of this + Ethernet over USB link + =============== ================================================== + +and after creating the functions/ecm.<instance name> they contain default +values: qmult is 5, dev_addr and host_addr are randomly selected. +The ifname can be written to if the function is not bound. A write must be an +interface pattern such as "usb%d", which will cause the net core to choose the +next free usbX interface. By default, it is set to "usb%d". + +Testing the ECM subset function +------------------------------- + +Configure IP addresses of the device and the host. Then: + +On the device:: + + ping <host's IP> + +On the host:: + + ping <device's IP> + +4. EEM function +=============== + +The function is provided by usb_f_eem.ko module. + +Function-specific configfs interface +------------------------------------ + +The function name to use when creating the function directory is "eem". +The EEM function provides these attributes in its function directory: + + =============== ================================================== + ifname network device interface name associated with this + function instance + qmult queue length multiplier for high and super speed + host_addr MAC address of host's end of this + Ethernet over USB link + dev_addr MAC address of device's end of this + Ethernet over USB link + =============== ================================================== + +and after creating the functions/eem.<instance name> they contain default +values: qmult is 5, dev_addr and host_addr are randomly selected. +The ifname can be written to if the function is not bound. A write must be an +interface pattern such as "usb%d", which will cause the net core to choose the +next free usbX interface. By default, it is set to "usb%d". + +Testing the EEM function +------------------------ + +Configure IP addresses of the device and the host. Then: + +On the device:: + + ping <host's IP> + +On the host:: + + ping <device's IP> + +5. FFS function +=============== + +The function is provided by usb_f_fs.ko module. + +Function-specific configfs interface +------------------------------------ + +The function name to use when creating the function directory is "ffs". +The function directory is intentionally empty and not modifiable. + +After creating the directory there is a new instance (a "device") of FunctionFS +available in the system. Once a "device" is available, the user should follow +the standard procedure for using FunctionFS (mount it, run the userspace +process which implements the function proper). The gadget should be enabled +by writing a suitable string to usb_gadget/<gadget>/UDC. + +Testing the FFS function +------------------------ + +On the device: start the function's userspace daemon, enable the gadget + +On the host: use the USB function provided by the device + +6. HID function +=============== + +The function is provided by usb_f_hid.ko module. + +Function-specific configfs interface +------------------------------------ + +The function name to use when creating the function directory is "hid". +The HID function provides these attributes in its function directory: + + =============== =========================================== + protocol HID protocol to use + report_desc data to be used in HID reports, except data + passed with /dev/hidg<X> + report_length HID report length + subclass HID subclass to use + =============== =========================================== + +For a keyboard the protocol and the subclass are 1, the report_length is 8, +while the report_desc is:: + + $ hd my_report_desc + 00000000 05 01 09 06 a1 01 05 07 19 e0 29 e7 15 00 25 01 |..........)...%.| + 00000010 75 01 95 08 81 02 95 01 75 08 81 03 95 05 75 01 |u.......u.....u.| + 00000020 05 08 19 01 29 05 91 02 95 01 75 03 91 03 95 06 |....).....u.....| + 00000030 75 08 15 00 25 65 05 07 19 00 29 65 81 00 c0 |u...%e....)e...| + 0000003f + +Such a sequence of bytes can be stored to the attribute with echo:: + + $ echo -ne \\x05\\x01\\x09\\x06\\xa1..... + +Testing the HID function +------------------------ + +Device: + +- create the gadget +- connect the gadget to a host, preferably not the one used + to control the gadget +- run a program which writes to /dev/hidg<N>, e.g. + a userspace program found in Documentation/usb/gadget_hid.rst:: + + $ ./hid_gadget_test /dev/hidg0 keyboard + +Host: + +- observe the keystrokes from the gadget + +7. LOOPBACK function +==================== + +The function is provided by usb_f_ss_lb.ko module. + +Function-specific configfs interface +------------------------------------ + +The function name to use when creating the function directory is "Loopback". +The LOOPBACK function provides these attributes in its function directory: + + =============== ======================= + qlen depth of loopback queue + bulk_buflen buffer length + =============== ======================= + +Testing the LOOPBACK function +----------------------------- + +device: run the gadget + +host: test-usb (tools/usb/testusb.c) + +8. MASS STORAGE function +======================== + +The function is provided by usb_f_mass_storage.ko module. + +Function-specific configfs interface +------------------------------------ + +The function name to use when creating the function directory is "mass_storage". +The MASS STORAGE function provides these attributes in its directory: +files: + + =============== ============================================== + stall Set to permit function to halt bulk endpoints. + Disabled on some USB devices known not to work + correctly. You should set it to true. + num_buffers Number of pipeline buffers. Valid numbers + are 2..4. Available only if + CONFIG_USB_GADGET_DEBUG_FILES is set. + =============== ============================================== + +and a default lun.0 directory corresponding to SCSI LUN #0. + +A new lun can be added with mkdir:: + + $ mkdir functions/mass_storage.0/partition.5 + +Lun numbering does not have to be continuous, except for lun #0 which is +created by default. A maximum of 8 luns can be specified and they all must be +named following the <name>.<number> scheme. The numbers can be 0..8. +Probably a good convention is to name the luns "lun.<number>", +although it is not mandatory. + +In each lun directory there are the following attribute files: + + =============== ============================================== + file The path to the backing file for the LUN. + Required if LUN is not marked as removable. + ro Flag specifying access to the LUN shall be + read-only. This is implied if CD-ROM emulation + is enabled as well as when it was impossible + to open "filename" in R/W mode. + removable Flag specifying that LUN shall be indicated as + being removable. + cdrom Flag specifying that LUN shall be reported as + being a CD-ROM. + nofua Flag specifying that FUA flag + in SCSI WRITE(10,12) + forced_eject This write-only file is useful only when + the function is active. It causes the backing + file to be forcibly detached from the LUN, + regardless of whether the host has allowed it. + Any non-zero number of bytes written will + result in ejection. + =============== ============================================== + +Testing the MASS STORAGE function +--------------------------------- + +device: connect the gadget, enable it +host: dmesg, see the USB drives appear (if system configured to automatically +mount) + +9. MIDI function +================ + +The function is provided by usb_f_midi.ko module. + +Function-specific configfs interface +------------------------------------ + +The function name to use when creating the function directory is "midi". +The MIDI function provides these attributes in its function directory: + + =============== ==================================== + buflen MIDI buffer length + id ID string for the USB MIDI adapter + in_ports number of MIDI input ports + index index value for the USB MIDI adapter + out_ports number of MIDI output ports + qlen USB read request queue length + =============== ==================================== + +Testing the MIDI function +------------------------- + +There are two cases: playing a mid from the gadget to +the host and playing a mid from the host to the gadget. + +1) Playing a mid from the gadget to the host: + +host:: + + $ arecordmidi -l + Port Client name Port name + 14:0 Midi Through Midi Through Port-0 + 24:0 MIDI Gadget MIDI Gadget MIDI 1 + $ arecordmidi -p 24:0 from_gadget.mid + +gadget:: + + $ aplaymidi -l + Port Client name Port name + 20:0 f_midi f_midi + + $ aplaymidi -p 20:0 to_host.mid + +2) Playing a mid from the host to the gadget + +gadget:: + + $ arecordmidi -l + Port Client name Port name + 20:0 f_midi f_midi + + $ arecordmidi -p 20:0 from_host.mid + +host:: + + $ aplaymidi -l + Port Client name Port name + 14:0 Midi Through Midi Through Port-0 + 24:0 MIDI Gadget MIDI Gadget MIDI 1 + + $ aplaymidi -p24:0 to_gadget.mid + +The from_gadget.mid should sound identical to the to_host.mid. + +The from_host.id should sound identical to the to_gadget.mid. + +MIDI files can be played to speakers/headphones with e.g. timidity installed:: + + $ aplaymidi -l + Port Client name Port name + 14:0 Midi Through Midi Through Port-0 + 24:0 MIDI Gadget MIDI Gadget MIDI 1 + 128:0 TiMidity TiMidity port 0 + 128:1 TiMidity TiMidity port 1 + 128:2 TiMidity TiMidity port 2 + 128:3 TiMidity TiMidity port 3 + + $ aplaymidi -p 128:0 file.mid + +MIDI ports can be logically connected using the aconnect utility, e.g.:: + + $ aconnect 24:0 128:0 # try it on the host + +After the gadget's MIDI port is connected to timidity's MIDI port, +whatever is played at the gadget side with aplaymidi -l is audible +in host's speakers/headphones. + +10. NCM function +================ + +The function is provided by usb_f_ncm.ko module. + +Function-specific configfs interface +------------------------------------ + +The function name to use when creating the function directory is "ncm". +The NCM function provides these attributes in its function directory: + + =============== ================================================== + ifname network device interface name associated with this + function instance + qmult queue length multiplier for high and super speed + host_addr MAC address of host's end of this + Ethernet over USB link + dev_addr MAC address of device's end of this + Ethernet over USB link + =============== ================================================== + +and after creating the functions/ncm.<instance name> they contain default +values: qmult is 5, dev_addr and host_addr are randomly selected. +The ifname can be written to if the function is not bound. A write must be an +interface pattern such as "usb%d", which will cause the net core to choose the +next free usbX interface. By default, it is set to "usb%d". + +Testing the NCM function +------------------------ + +Configure IP addresses of the device and the host. Then: + +On the device:: + + ping <host's IP> + +On the host:: + + ping <device's IP> + +11. OBEX function +================= + +The function is provided by usb_f_obex.ko module. + +Function-specific configfs interface +------------------------------------ + +The function name to use when creating the function directory is "obex". +The OBEX function provides just one attribute in its function directory: + + port_num + +The attribute is read-only. + +There can be at most 4 ACM/generic serial/OBEX ports in the system. + +Testing the OBEX function +------------------------- + +On device:: + + seriald -f /dev/ttyGS<Y> -s 1024 + +On host:: + + serialc -v <vendorID> -p <productID> -i<interface#> -a1 -s1024 \ + -t<out endpoint addr> -r<in endpoint addr> + +where seriald and serialc are Felipe's utilities found here: + + https://github.com/felipebalbi/usb-tools.git master + +12. PHONET function +=================== + +The function is provided by usb_f_phonet.ko module. + +Function-specific configfs interface +------------------------------------ + +The function name to use when creating the function directory is "phonet". +The PHONET function provides just one attribute in its function directory: + + =============== ================================================== + ifname network device interface name associated with this + function instance + =============== ================================================== + +Testing the PHONET function +--------------------------- + +It is not possible to test the SOCK_STREAM protocol without a specific piece +of hardware, so only SOCK_DGRAM has been tested. For the latter to work, +in the past I had to apply the patch mentioned here: + +http://www.spinics.net/lists/linux-usb/msg85689.html + +These tools are required: + +git://git.gitorious.org/meego-cellular/phonet-utils.git + +On the host:: + + $ ./phonet -a 0x10 -i usbpn0 + $ ./pnroute add 0x6c usbpn0 + $./pnroute add 0x10 usbpn0 + $ ifconfig usbpn0 up + +On the device:: + + $ ./phonet -a 0x6c -i upnlink0 + $ ./pnroute add 0x10 upnlink0 + $ ifconfig upnlink0 up + +Then a test program can be used:: + + http://www.spinics.net/lists/linux-usb/msg85690.html + +On the device:: + + $ ./pnxmit -a 0x6c -r + +On the host:: + + $ ./pnxmit -a 0x10 -s 0x6c + +As a result some data should be sent from host to device. +Then the other way round: + +On the host:: + + $ ./pnxmit -a 0x10 -r + +On the device:: + + $ ./pnxmit -a 0x6c -s 0x10 + +13. RNDIS function +================== + +The function is provided by usb_f_rndis.ko module. + +Function-specific configfs interface +------------------------------------ + +The function name to use when creating the function directory is "rndis". +The RNDIS function provides these attributes in its function directory: + + =============== ================================================== + ifname network device interface name associated with this + function instance + qmult queue length multiplier for high and super speed + host_addr MAC address of host's end of this + Ethernet over USB link + dev_addr MAC address of device's end of this + Ethernet over USB link + =============== ================================================== + +and after creating the functions/rndis.<instance name> they contain default +values: qmult is 5, dev_addr and host_addr are randomly selected. +The ifname can be written to if the function is not bound. A write must be an +interface pattern such as "usb%d", which will cause the net core to choose the +next free usbX interface. By default, it is set to "usb%d". + +Testing the RNDIS function +-------------------------- + +Configure IP addresses of the device and the host. Then: + +On the device:: + + ping <host's IP> + +On the host:: + + ping <device's IP> + +14. SERIAL function +=================== + +The function is provided by usb_f_gser.ko module. + +Function-specific configfs interface +------------------------------------ + +The function name to use when creating the function directory is "gser". +The SERIAL function provides just one attribute in its function directory: + + port_num + +The attribute is read-only. + +There can be at most 4 ACM/generic serial/OBEX ports in the system. + +Testing the SERIAL function +--------------------------- + +On host:: + + insmod usbserial + echo VID PID >/sys/bus/usb-serial/drivers/generic/new_id + +On host:: + + cat > /dev/ttyUSB<X> + +On target:: + + cat /dev/ttyGS<Y> + +then the other way round + +On target:: + + cat > /dev/ttyGS<Y> + +On host:: + + cat /dev/ttyUSB<X> + +15. SOURCESINK function +======================= + +The function is provided by usb_f_ss_lb.ko module. + +Function-specific configfs interface +------------------------------------ + +The function name to use when creating the function directory is "SourceSink". +The SOURCESINK function provides these attributes in its function directory: + + =============== ================================== + pattern 0 (all zeros), 1 (mod63), 2 (none) + isoc_interval 1..16 + isoc_maxpacket 0 - 1023 (fs), 0 - 1024 (hs/ss) + isoc_mult 0..2 (hs/ss only) + isoc_maxburst 0..15 (ss only) + bulk_buflen buffer length + bulk_qlen depth of queue for bulk + iso_qlen depth of queue for iso + =============== ================================== + +Testing the SOURCESINK function +------------------------------- + +device: run the gadget + +host: test-usb (tools/usb/testusb.c) + + +16. UAC1 function (legacy implementation) +========================================= + +The function is provided by usb_f_uac1_legacy.ko module. + +Function-specific configfs interface +------------------------------------ + +The function name to use when creating the function directory +is "uac1_legacy". +The uac1 function provides these attributes in its function directory: + + =============== ==================================== + audio_buf_size audio buffer size + fn_cap capture pcm device file name + fn_cntl control device file name + fn_play playback pcm device file name + req_buf_size ISO OUT endpoint request buffer size + req_count ISO OUT endpoint request count + =============== ==================================== + +The attributes have sane default values. + +Testing the UAC1 function +------------------------- + +device: run the gadget + +host:: + + aplay -l # should list our USB Audio Gadget + +17. UAC2 function +================= + +The function is provided by usb_f_uac2.ko module. + +Function-specific configfs interface +------------------------------------ + +The function name to use when creating the function directory is "uac2". +The uac2 function provides these attributes in its function directory: + + ================ ==================================================== + c_chmask capture channel mask + c_srate list of capture sampling rates (comma-separated) + c_ssize capture sample size (bytes) + c_sync capture synchronization type (async/adaptive) + c_mute_present capture mute control enable + c_volume_present capture volume control enable + c_volume_min capture volume control min value (in 1/256 dB) + c_volume_max capture volume control max value (in 1/256 dB) + c_volume_res capture volume control resolution (in 1/256 dB) + c_hs_bint capture bInterval for HS/SS (1-4: fixed, 0: auto) + fb_max maximum extra bandwidth in async mode + p_chmask playback channel mask + p_srate list of playback sampling rates (comma-separated) + p_ssize playback sample size (bytes) + p_mute_present playback mute control enable + p_volume_present playback volume control enable + p_volume_min playback volume control min value (in 1/256 dB) + p_volume_max playback volume control max value (in 1/256 dB) + p_volume_res playback volume control resolution (in 1/256 dB) + p_hs_bint playback bInterval for HS/SS (1-4: fixed, 0: auto) + req_number the number of pre-allocated request for both capture + and playback + function_name name of the interface + ================ ==================================================== + +The attributes have sane default values. + +Testing the UAC2 function +------------------------- + +device: run the gadget +host: aplay -l # should list our USB Audio Gadget + +This function does not require real hardware support, it just +sends a stream of audio data to/from the host. In order to +actually hear something at the device side, a command similar +to this must be used at the device side:: + + $ arecord -f dat -t wav -D hw:2,0 | aplay -D hw:0,0 & + +e.g.:: + + $ arecord -f dat -t wav -D hw:CARD=UAC2Gadget,DEV=0 | \ + aplay -D default:CARD=OdroidU3 + +18. UVC function +================ + +The function is provided by usb_f_uvc.ko module. + +Function-specific configfs interface +------------------------------------ + +The function name to use when creating the function directory is "uvc". +The uvc function provides these attributes in its function directory: + + =================== ================================================ + streaming_interval interval for polling endpoint for data transfers + streaming_maxburst bMaxBurst for super speed companion descriptor + streaming_maxpacket maximum packet size this endpoint is capable of + sending or receiving when this configuration is + selected + function_name name of the interface + =================== ================================================ + +There are also "control" and "streaming" subdirectories, each of which contain +a number of their subdirectories. There are some sane defaults provided, but +the user must provide the following: + + ================== ==================================================== + control header create in control/header, link from control/class/fs + and/or control/class/ss + streaming header create in streaming/header, link from + streaming/class/fs and/or streaming/class/hs and/or + streaming/class/ss + format description create in streaming/mjpeg and/or + streaming/uncompressed + frame description create in streaming/mjpeg/<format> and/or in + streaming/uncompressed/<format> + ================== ==================================================== + +Each frame description contains frame interval specification, and each +such specification consists of a number of lines with an inverval value +in each line. The rules stated above are best illustrated with an example:: + + # mkdir functions/uvc.usb0/control/header/h + # cd functions/uvc.usb0/control/ + # ln -s header/h class/fs + # ln -s header/h class/ss + # mkdir -p functions/uvc.usb0/streaming/uncompressed/u/360p + # cat <<EOF > functions/uvc.usb0/streaming/uncompressed/u/360p/dwFrameInterval + 666666 + 1000000 + 5000000 + EOF + # cd $GADGET_CONFIGFS_ROOT + # mkdir functions/uvc.usb0/streaming/header/h + # cd functions/uvc.usb0/streaming/header/h + # ln -s ../../uncompressed/u + # cd ../../class/fs + # ln -s ../../header/h + # cd ../../class/hs + # ln -s ../../header/h + # cd ../../class/ss + # ln -s ../../header/h + + +Testing the UVC function +------------------------ + +device: run the gadget, modprobe vivid:: + + # uvc-gadget -u /dev/video<uvc video node #> -v /dev/video<vivid video node #> + +where uvc-gadget is this program: + http://git.ideasonboard.org/uvc-gadget.git + +with these patches: + + http://www.spinics.net/lists/linux-usb/msg99220.html + +host:: + + luvcview -f yuv + +19. PRINTER function +==================== + +The function is provided by usb_f_printer.ko module. + +Function-specific configfs interface +------------------------------------ + +The function name to use when creating the function directory is "printer". +The printer function provides these attributes in its function directory: + + ========== =========================================== + pnp_string Data to be passed to the host in pnp string + q_len Number of requests per endpoint + ========== =========================================== + +Testing the PRINTER function +---------------------------- + +The most basic testing: + +device: run the gadget:: + + # ls -l /devices/virtual/usb_printer_gadget/ + +should show g_printer<number>. + +If udev is active, then /dev/g_printer<number> should appear automatically. + +host: + +If udev is active, then e.g. /dev/usb/lp0 should appear. + +host->device transmission: + +device:: + + # cat /dev/g_printer<number> + +host:: + + # cat > /dev/usb/lp0 + +device->host transmission:: + + # cat > /dev/g_printer<number> + +host:: + + # cat /dev/usb/lp0 + +More advanced testing can be done with the prn_example +described in Documentation/usb/gadget_printer.rst. + + +20. UAC1 function (virtual ALSA card, using u_audio API) +======================================================== + +The function is provided by usb_f_uac1.ko module. +It will create a virtual ALSA card and the audio streams are simply +sinked to and sourced from it. + +Function-specific configfs interface +------------------------------------ + +The function name to use when creating the function directory is "uac1". +The uac1 function provides these attributes in its function directory: + + ================ ==================================================== + c_chmask capture channel mask + c_srate list of capture sampling rates (comma-separated) + c_ssize capture sample size (bytes) + c_mute_present capture mute control enable + c_volume_present capture volume control enable + c_volume_min capture volume control min value (in 1/256 dB) + c_volume_max capture volume control max value (in 1/256 dB) + c_volume_res capture volume control resolution (in 1/256 dB) + p_chmask playback channel mask + p_srate list of playback sampling rates (comma-separated) + p_ssize playback sample size (bytes) + p_mute_present playback mute control enable + p_volume_present playback volume control enable + p_volume_min playback volume control min value (in 1/256 dB) + p_volume_max playback volume control max value (in 1/256 dB) + p_volume_res playback volume control resolution (in 1/256 dB) + req_number the number of pre-allocated requests for both capture + and playback + function_name name of the interface + ================ ==================================================== + +The attributes have sane default values. + +Testing the UAC1 function +------------------------- + +device: run the gadget +host: aplay -l # should list our USB Audio Gadget + +This function does not require real hardware support, it just +sends a stream of audio data to/from the host. In order to +actually hear something at the device side, a command similar +to this must be used at the device side:: + + $ arecord -f dat -t wav -D hw:2,0 | aplay -D hw:0,0 & + +e.g.:: + + $ arecord -f dat -t wav -D hw:CARD=UAC1Gadget,DEV=0 | \ + aplay -D default:CARD=OdroidU3 diff --git a/Documentation/usb/gadget_configfs.rst b/Documentation/usb/gadget_configfs.rst new file mode 100644 index 000000000..e4566ffb2 --- /dev/null +++ b/Documentation/usb/gadget_configfs.rst @@ -0,0 +1,390 @@ +============================================ +Linux USB gadget configured through configfs +============================================ + + +25th April 2013 + + + + +Overview +======== + +A USB Linux Gadget is a device which has a UDC (USB Device Controller) and can +be connected to a USB Host to extend it with additional functions like a serial +port or a mass storage capability. + +A gadget is seen by its host as a set of configurations, each of which contains +a number of interfaces which, from the gadget's perspective, are known as +functions, each function representing e.g. a serial connection or a SCSI disk. + +Linux provides a number of functions for gadgets to use. + +Creating a gadget means deciding what configurations there will be +and which functions each configuration will provide. + +Configfs (please see `Documentation/filesystems/configfs.rst`) lends itself nicely +for the purpose of telling the kernel about the above mentioned decision. +This document is about how to do it. + +It also describes how configfs integration into gadget is designed. + + + + +Requirements +============ + +In order for this to work configfs must be available, so CONFIGFS_FS must be +'y' or 'm' in .config. As of this writing USB_LIBCOMPOSITE selects CONFIGFS_FS. + + + + +Usage +===== + +(The original post describing the first function +made available through configfs can be seen here: +http://www.spinics.net/lists/linux-usb/msg76388.html) + +:: + + $ modprobe libcomposite + $ mount none $CONFIGFS_HOME -t configfs + +where CONFIGFS_HOME is the mount point for configfs + +1. Creating the gadgets +----------------------- + +For each gadget to be created its corresponding directory must be created:: + + $ mkdir $CONFIGFS_HOME/usb_gadget/<gadget name> + +e.g.:: + + $ mkdir $CONFIGFS_HOME/usb_gadget/g1 + + ... + ... + ... + + $ cd $CONFIGFS_HOME/usb_gadget/g1 + +Each gadget needs to have its vendor id <VID> and product id <PID> specified:: + + $ echo <VID> > idVendor + $ echo <PID> > idProduct + +A gadget also needs its serial number, manufacturer and product strings. +In order to have a place to store them, a strings subdirectory must be created +for each language, e.g.:: + + $ mkdir strings/0x409 + +Then the strings can be specified:: + + $ echo <serial number> > strings/0x409/serialnumber + $ echo <manufacturer> > strings/0x409/manufacturer + $ echo <product> > strings/0x409/product + +2. Creating the configurations +------------------------------ + +Each gadget will consist of a number of configurations, their corresponding +directories must be created: + +$ mkdir configs/<name>.<number> + +where <name> can be any string which is legal in a filesystem and the +<number> is the configuration's number, e.g.:: + + $ mkdir configs/c.1 + + ... + ... + ... + +Each configuration also needs its strings, so a subdirectory must be created +for each language, e.g.:: + + $ mkdir configs/c.1/strings/0x409 + +Then the configuration string can be specified:: + + $ echo <configuration> > configs/c.1/strings/0x409/configuration + +Some attributes can also be set for a configuration, e.g.:: + + $ echo 120 > configs/c.1/MaxPower + +3. Creating the functions +------------------------- + +The gadget will provide some functions, for each function its corresponding +directory must be created:: + + $ mkdir functions/<name>.<instance name> + +where <name> corresponds to one of allowed function names and instance name +is an arbitrary string allowed in a filesystem, e.g.:: + + $ mkdir functions/ncm.usb0 # usb_f_ncm.ko gets loaded with request_module() + + ... + ... + ... + +Each function provides its specific set of attributes, with either read-only +or read-write access. Where applicable they need to be written to as +appropriate. +Please refer to Documentation/ABI/testing/configfs-usb-gadget for more information. + +4. Associating the functions with their configurations +------------------------------------------------------ + +At this moment a number of gadgets is created, each of which has a number of +configurations specified and a number of functions available. What remains +is specifying which function is available in which configuration (the same +function can be used in multiple configurations). This is achieved with +creating symbolic links:: + + $ ln -s functions/<name>.<instance name> configs/<name>.<number> + +e.g.:: + + $ ln -s functions/ncm.usb0 configs/c.1 + + ... + ... + ... + +5. Enabling the gadget +---------------------- + +All the above steps serve the purpose of composing the gadget of +configurations and functions. + +An example directory structure might look like this:: + + . + ./strings + ./strings/0x409 + ./strings/0x409/serialnumber + ./strings/0x409/product + ./strings/0x409/manufacturer + ./configs + ./configs/c.1 + ./configs/c.1/ncm.usb0 -> ../../../../usb_gadget/g1/functions/ncm.usb0 + ./configs/c.1/strings + ./configs/c.1/strings/0x409 + ./configs/c.1/strings/0x409/configuration + ./configs/c.1/bmAttributes + ./configs/c.1/MaxPower + ./functions + ./functions/ncm.usb0 + ./functions/ncm.usb0/ifname + ./functions/ncm.usb0/qmult + ./functions/ncm.usb0/host_addr + ./functions/ncm.usb0/dev_addr + ./UDC + ./bcdUSB + ./bcdDevice + ./idProduct + ./idVendor + ./bMaxPacketSize0 + ./bDeviceProtocol + ./bDeviceSubClass + ./bDeviceClass + + +Such a gadget must be finally enabled so that the USB host can enumerate it. + +In order to enable the gadget it must be bound to a UDC (USB Device +Controller):: + + $ echo <udc name> > UDC + +where <udc name> is one of those found in /sys/class/udc/* +e.g.:: + + $ echo s3c-hsotg > UDC + + +6. Disabling the gadget +----------------------- + +:: + + $ echo "" > UDC + +7. Cleaning up +-------------- + +Remove functions from configurations:: + + $ rm configs/<config name>.<number>/<function> + +where <config name>.<number> specify the configuration and <function> is +a symlink to a function being removed from the configuration, e.g.:: + + $ rm configs/c.1/ncm.usb0 + + ... + ... + ... + +Remove strings directories in configurations: + + $ rmdir configs/<config name>.<number>/strings/<lang> + +e.g.:: + + $ rmdir configs/c.1/strings/0x409 + + ... + ... + ... + +and remove the configurations:: + + $ rmdir configs/<config name>.<number> + +e.g.:: + + rmdir configs/c.1 + + ... + ... + ... + +Remove functions (function modules are not unloaded, though): + + $ rmdir functions/<name>.<instance name> + +e.g.:: + + $ rmdir functions/ncm.usb0 + + ... + ... + ... + +Remove strings directories in the gadget:: + + $ rmdir strings/<lang> + +e.g.:: + + $ rmdir strings/0x409 + +and finally remove the gadget:: + + $ cd .. + $ rmdir <gadget name> + +e.g.:: + + $ rmdir g1 + + + + +Implementation design +===================== + +Below the idea of how configfs works is presented. +In configfs there are items and groups, both represented as directories. +The difference between an item and a group is that a group can contain +other groups. In the picture below only an item is shown. +Both items and groups can have attributes, which are represented as files. +The user can create and remove directories, but cannot remove files, +which can be read-only or read-write, depending on what they represent. + +The filesystem part of configfs operates on config_items/groups and +configfs_attributes which are generic and of the same type for all +configured elements. However, they are embedded in usage-specific +larger structures. In the picture below there is a "cs" which contains +a config_item and an "sa" which contains a configfs_attribute. + +The filesystem view would be like this:: + + ./ + ./cs (directory) + | + +--sa (file) + | + . + . + . + +Whenever a user reads/writes the "sa" file, a function is called +which accepts a struct config_item and a struct configfs_attribute. +In the said function the "cs" and "sa" are retrieved using the well +known container_of technique and an appropriate sa's function (show or +store) is called and passed the "cs" and a character buffer. The "show" +is for displaying the file's contents (copy data from the cs to the +buffer), while the "store" is for modifying the file's contents (copy data +from the buffer to the cs), but it is up to the implementer of the +two functions to decide what they actually do. + +:: + + typedef struct configured_structure cs; + typedef struct specific_attribute sa; + + sa + +----------------------------------+ + cs | (*show)(cs *, buffer); | + +-----------------+ | (*store)(cs *, buffer, length); | + | | | | + | +-------------+ | | +------------------+ | + | | struct |-|----|------>|struct | | + | | config_item | | | |configfs_attribute| | + | +-------------+ | | +------------------+ | + | | +----------------------------------+ + | data to be set | . + | | . + +-----------------+ . + +The file names are decided by the config item/group designer, while +the directories in general can be named at will. A group can have +a number of its default sub-groups created automatically. + +For more information on configfs please see +`Documentation/filesystems/configfs.rst`. + +The concepts described above translate to USB gadgets like this: + +1. A gadget has its config group, which has some attributes (idVendor, +idProduct etc) and default sub-groups (configs, functions, strings). +Writing to the attributes causes the information to be stored in +appropriate locations. In the configs, functions and strings sub-groups +a user can create their sub-groups to represent configurations, functions, +and groups of strings in a given language. + +2. The user creates configurations and functions, in the configurations +creates symbolic links to functions. This information is used when the +gadget's UDC attribute is written to, which means binding the gadget +to the UDC. The code in drivers/usb/gadget/configfs.c iterates over +all configurations, and in each configuration it iterates over all +functions and binds them. This way the whole gadget is bound. + +3. The file drivers/usb/gadget/configfs.c contains code for + + - gadget's config_group + - gadget's default groups (configs, functions, strings) + - associating functions with configurations (symlinks) + +4. Each USB function naturally has its own view of what it wants +configured, so config_groups for particular functions are defined +in the functions implementation files drivers/usb/gadget/f_*.c. + +5. Function's code is written in such a way that it uses + +usb_get_function_instance(), which, in turn, calls request_module. +So, provided that modprobe works, modules for particular functions +are loaded automatically. Please note that the converse is not true: +after a gadget is disabled and torn down, the modules remain loaded. diff --git a/Documentation/usb/gadget_hid.rst b/Documentation/usb/gadget_hid.rst new file mode 100644 index 000000000..e623416de --- /dev/null +++ b/Documentation/usb/gadget_hid.rst @@ -0,0 +1,457 @@ +=========================== +Linux USB HID gadget driver +=========================== + +Introduction +============ + +The HID Gadget driver provides emulation of USB Human Interface +Devices (HID). The basic HID handling is done in the kernel, +and HID reports can be sent/received through I/O on the +/dev/hidgX character devices. + +For more details about HID, see the developer page on +https://www.usb.org/developers/hidpage/ + +Configuration +============= + +g_hid is a platform driver, so to use it you need to add +struct platform_device(s) to your platform code defining the +HID function descriptors you want to use - E.G. something +like:: + + #include <linux/platform_device.h> + #include <linux/usb/g_hid.h> + + /* hid descriptor for a keyboard */ + static struct hidg_func_descriptor my_hid_data = { + .subclass = 0, /* No subclass */ + .protocol = 1, /* Keyboard */ + .report_length = 8, + .report_desc_length = 63, + .report_desc = { + 0x05, 0x01, /* USAGE_PAGE (Generic Desktop) */ + 0x09, 0x06, /* USAGE (Keyboard) */ + 0xa1, 0x01, /* COLLECTION (Application) */ + 0x05, 0x07, /* USAGE_PAGE (Keyboard) */ + 0x19, 0xe0, /* USAGE_MINIMUM (Keyboard LeftControl) */ + 0x29, 0xe7, /* USAGE_MAXIMUM (Keyboard Right GUI) */ + 0x15, 0x00, /* LOGICAL_MINIMUM (0) */ + 0x25, 0x01, /* LOGICAL_MAXIMUM (1) */ + 0x75, 0x01, /* REPORT_SIZE (1) */ + 0x95, 0x08, /* REPORT_COUNT (8) */ + 0x81, 0x02, /* INPUT (Data,Var,Abs) */ + 0x95, 0x01, /* REPORT_COUNT (1) */ + 0x75, 0x08, /* REPORT_SIZE (8) */ + 0x81, 0x03, /* INPUT (Cnst,Var,Abs) */ + 0x95, 0x05, /* REPORT_COUNT (5) */ + 0x75, 0x01, /* REPORT_SIZE (1) */ + 0x05, 0x08, /* USAGE_PAGE (LEDs) */ + 0x19, 0x01, /* USAGE_MINIMUM (Num Lock) */ + 0x29, 0x05, /* USAGE_MAXIMUM (Kana) */ + 0x91, 0x02, /* OUTPUT (Data,Var,Abs) */ + 0x95, 0x01, /* REPORT_COUNT (1) */ + 0x75, 0x03, /* REPORT_SIZE (3) */ + 0x91, 0x03, /* OUTPUT (Cnst,Var,Abs) */ + 0x95, 0x06, /* REPORT_COUNT (6) */ + 0x75, 0x08, /* REPORT_SIZE (8) */ + 0x15, 0x00, /* LOGICAL_MINIMUM (0) */ + 0x25, 0x65, /* LOGICAL_MAXIMUM (101) */ + 0x05, 0x07, /* USAGE_PAGE (Keyboard) */ + 0x19, 0x00, /* USAGE_MINIMUM (Reserved) */ + 0x29, 0x65, /* USAGE_MAXIMUM (Keyboard Application) */ + 0x81, 0x00, /* INPUT (Data,Ary,Abs) */ + 0xc0 /* END_COLLECTION */ + } + }; + + static struct platform_device my_hid = { + .name = "hidg", + .id = 0, + .num_resources = 0, + .resource = 0, + .dev.platform_data = &my_hid_data, + }; + +You can add as many HID functions as you want, only limited by +the amount of interrupt endpoints your gadget driver supports. + +Configuration with configfs +=========================== + +Instead of adding fake platform devices and drivers in order to pass +some data to the kernel, if HID is a part of a gadget composed with +configfs the hidg_func_descriptor.report_desc is passed to the kernel +by writing the appropriate stream of bytes to a configfs attribute. + +Send and receive HID reports +============================ + +HID reports can be sent/received using read/write on the +/dev/hidgX character devices. See below for an example program +to do this. + +hid_gadget_test is a small interactive program to test the HID +gadget driver. To use, point it at a hidg device and set the +device type (keyboard / mouse / joystick) - E.G.:: + + # hid_gadget_test /dev/hidg0 keyboard + +You are now in the prompt of hid_gadget_test. You can type any +combination of options and values. Available options and +values are listed at program start. In keyboard mode you can +send up to six values. + +For example type: g i s t r --left-shift + +Hit return and the corresponding report will be sent by the +HID gadget. + +Another interesting example is the caps lock test. Type +--caps-lock and hit return. A report is then sent by the +gadget and you should receive the host answer, corresponding +to the caps lock LED status:: + + --caps-lock + recv report:2 + +With this command:: + + # hid_gadget_test /dev/hidg1 mouse + +You can test the mouse emulation. Values are two signed numbers. + + +Sample code:: + + /* hid_gadget_test */ + + #include <pthread.h> + #include <string.h> + #include <stdio.h> + #include <ctype.h> + #include <fcntl.h> + #include <errno.h> + #include <stdio.h> + #include <stdlib.h> + #include <unistd.h> + + #define BUF_LEN 512 + + struct options { + const char *opt; + unsigned char val; + }; + + static struct options kmod[] = { + {.opt = "--left-ctrl", .val = 0x01}, + {.opt = "--right-ctrl", .val = 0x10}, + {.opt = "--left-shift", .val = 0x02}, + {.opt = "--right-shift", .val = 0x20}, + {.opt = "--left-alt", .val = 0x04}, + {.opt = "--right-alt", .val = 0x40}, + {.opt = "--left-meta", .val = 0x08}, + {.opt = "--right-meta", .val = 0x80}, + {.opt = NULL} + }; + + static struct options kval[] = { + {.opt = "--return", .val = 0x28}, + {.opt = "--esc", .val = 0x29}, + {.opt = "--bckspc", .val = 0x2a}, + {.opt = "--tab", .val = 0x2b}, + {.opt = "--spacebar", .val = 0x2c}, + {.opt = "--caps-lock", .val = 0x39}, + {.opt = "--f1", .val = 0x3a}, + {.opt = "--f2", .val = 0x3b}, + {.opt = "--f3", .val = 0x3c}, + {.opt = "--f4", .val = 0x3d}, + {.opt = "--f5", .val = 0x3e}, + {.opt = "--f6", .val = 0x3f}, + {.opt = "--f7", .val = 0x40}, + {.opt = "--f8", .val = 0x41}, + {.opt = "--f9", .val = 0x42}, + {.opt = "--f10", .val = 0x43}, + {.opt = "--f11", .val = 0x44}, + {.opt = "--f12", .val = 0x45}, + {.opt = "--insert", .val = 0x49}, + {.opt = "--home", .val = 0x4a}, + {.opt = "--pageup", .val = 0x4b}, + {.opt = "--del", .val = 0x4c}, + {.opt = "--end", .val = 0x4d}, + {.opt = "--pagedown", .val = 0x4e}, + {.opt = "--right", .val = 0x4f}, + {.opt = "--left", .val = 0x50}, + {.opt = "--down", .val = 0x51}, + {.opt = "--kp-enter", .val = 0x58}, + {.opt = "--up", .val = 0x52}, + {.opt = "--num-lock", .val = 0x53}, + {.opt = NULL} + }; + + int keyboard_fill_report(char report[8], char buf[BUF_LEN], int *hold) + { + char *tok = strtok(buf, " "); + int key = 0; + int i = 0; + + for (; tok != NULL; tok = strtok(NULL, " ")) { + + if (strcmp(tok, "--quit") == 0) + return -1; + + if (strcmp(tok, "--hold") == 0) { + *hold = 1; + continue; + } + + if (key < 6) { + for (i = 0; kval[i].opt != NULL; i++) + if (strcmp(tok, kval[i].opt) == 0) { + report[2 + key++] = kval[i].val; + break; + } + if (kval[i].opt != NULL) + continue; + } + + if (key < 6) + if (islower(tok[0])) { + report[2 + key++] = (tok[0] - ('a' - 0x04)); + continue; + } + + for (i = 0; kmod[i].opt != NULL; i++) + if (strcmp(tok, kmod[i].opt) == 0) { + report[0] = report[0] | kmod[i].val; + break; + } + if (kmod[i].opt != NULL) + continue; + + if (key < 6) + fprintf(stderr, "unknown option: %s\n", tok); + } + return 8; + } + + static struct options mmod[] = { + {.opt = "--b1", .val = 0x01}, + {.opt = "--b2", .val = 0x02}, + {.opt = "--b3", .val = 0x04}, + {.opt = NULL} + }; + + int mouse_fill_report(char report[8], char buf[BUF_LEN], int *hold) + { + char *tok = strtok(buf, " "); + int mvt = 0; + int i = 0; + for (; tok != NULL; tok = strtok(NULL, " ")) { + + if (strcmp(tok, "--quit") == 0) + return -1; + + if (strcmp(tok, "--hold") == 0) { + *hold = 1; + continue; + } + + for (i = 0; mmod[i].opt != NULL; i++) + if (strcmp(tok, mmod[i].opt) == 0) { + report[0] = report[0] | mmod[i].val; + break; + } + if (mmod[i].opt != NULL) + continue; + + if (!(tok[0] == '-' && tok[1] == '-') && mvt < 2) { + errno = 0; + report[1 + mvt++] = (char)strtol(tok, NULL, 0); + if (errno != 0) { + fprintf(stderr, "Bad value:'%s'\n", tok); + report[1 + mvt--] = 0; + } + continue; + } + + fprintf(stderr, "unknown option: %s\n", tok); + } + return 3; + } + + static struct options jmod[] = { + {.opt = "--b1", .val = 0x10}, + {.opt = "--b2", .val = 0x20}, + {.opt = "--b3", .val = 0x40}, + {.opt = "--b4", .val = 0x80}, + {.opt = "--hat1", .val = 0x00}, + {.opt = "--hat2", .val = 0x01}, + {.opt = "--hat3", .val = 0x02}, + {.opt = "--hat4", .val = 0x03}, + {.opt = "--hatneutral", .val = 0x04}, + {.opt = NULL} + }; + + int joystick_fill_report(char report[8], char buf[BUF_LEN], int *hold) + { + char *tok = strtok(buf, " "); + int mvt = 0; + int i = 0; + + *hold = 1; + + /* set default hat position: neutral */ + report[3] = 0x04; + + for (; tok != NULL; tok = strtok(NULL, " ")) { + + if (strcmp(tok, "--quit") == 0) + return -1; + + for (i = 0; jmod[i].opt != NULL; i++) + if (strcmp(tok, jmod[i].opt) == 0) { + report[3] = (report[3] & 0xF0) | jmod[i].val; + break; + } + if (jmod[i].opt != NULL) + continue; + + if (!(tok[0] == '-' && tok[1] == '-') && mvt < 3) { + errno = 0; + report[mvt++] = (char)strtol(tok, NULL, 0); + if (errno != 0) { + fprintf(stderr, "Bad value:'%s'\n", tok); + report[mvt--] = 0; + } + continue; + } + + fprintf(stderr, "unknown option: %s\n", tok); + } + return 4; + } + + void print_options(char c) + { + int i = 0; + + if (c == 'k') { + printf(" keyboard options:\n" + " --hold\n"); + for (i = 0; kmod[i].opt != NULL; i++) + printf("\t\t%s\n", kmod[i].opt); + printf("\n keyboard values:\n" + " [a-z] or\n"); + for (i = 0; kval[i].opt != NULL; i++) + printf("\t\t%-8s%s", kval[i].opt, i % 2 ? "\n" : ""); + printf("\n"); + } else if (c == 'm') { + printf(" mouse options:\n" + " --hold\n"); + for (i = 0; mmod[i].opt != NULL; i++) + printf("\t\t%s\n", mmod[i].opt); + printf("\n mouse values:\n" + " Two signed numbers\n" + "--quit to close\n"); + } else { + printf(" joystick options:\n"); + for (i = 0; jmod[i].opt != NULL; i++) + printf("\t\t%s\n", jmod[i].opt); + printf("\n joystick values:\n" + " three signed numbers\n" + "--quit to close\n"); + } + } + + int main(int argc, const char *argv[]) + { + const char *filename = NULL; + int fd = 0; + char buf[BUF_LEN]; + int cmd_len; + char report[8]; + int to_send = 8; + int hold = 0; + fd_set rfds; + int retval, i; + + if (argc < 3) { + fprintf(stderr, "Usage: %s devname mouse|keyboard|joystick\n", + argv[0]); + return 1; + } + + if (argv[2][0] != 'k' && argv[2][0] != 'm' && argv[2][0] != 'j') + return 2; + + filename = argv[1]; + + if ((fd = open(filename, O_RDWR, 0666)) == -1) { + perror(filename); + return 3; + } + + print_options(argv[2][0]); + + while (42) { + + FD_ZERO(&rfds); + FD_SET(STDIN_FILENO, &rfds); + FD_SET(fd, &rfds); + + retval = select(fd + 1, &rfds, NULL, NULL, NULL); + if (retval == -1 && errno == EINTR) + continue; + if (retval < 0) { + perror("select()"); + return 4; + } + + if (FD_ISSET(fd, &rfds)) { + cmd_len = read(fd, buf, BUF_LEN - 1); + printf("recv report:"); + for (i = 0; i < cmd_len; i++) + printf(" %02x", buf[i]); + printf("\n"); + } + + if (FD_ISSET(STDIN_FILENO, &rfds)) { + memset(report, 0x0, sizeof(report)); + cmd_len = read(STDIN_FILENO, buf, BUF_LEN - 1); + + if (cmd_len == 0) + break; + + buf[cmd_len - 1] = '\0'; + hold = 0; + + memset(report, 0x0, sizeof(report)); + if (argv[2][0] == 'k') + to_send = keyboard_fill_report(report, buf, &hold); + else if (argv[2][0] == 'm') + to_send = mouse_fill_report(report, buf, &hold); + else + to_send = joystick_fill_report(report, buf, &hold); + + if (to_send == -1) + break; + + if (write(fd, report, to_send) != to_send) { + perror(filename); + return 5; + } + if (!hold) { + memset(report, 0x0, sizeof(report)); + if (write(fd, report, to_send) != to_send) { + perror(filename); + return 6; + } + } + } + } + + close(fd); + return 0; + } diff --git a/Documentation/usb/gadget_multi.rst b/Documentation/usb/gadget_multi.rst new file mode 100644 index 000000000..3a22c1b2f --- /dev/null +++ b/Documentation/usb/gadget_multi.rst @@ -0,0 +1,165 @@ +============================== +Multifunction Composite Gadget +============================== + +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 note 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 to 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 match 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, +[[https://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] [[https://msdn.microsoft.com/en-us/library/ff537109(v=VS.85).aspx]] + +[5] [[https://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] https://www.nirsoft.net/utils/usb_devices_view.html + +[9] [[https://msdn.microsoft.com/en-us/library/ff570620.aspx]] diff --git a/Documentation/usb/gadget_printer.rst b/Documentation/usb/gadget_printer.rst new file mode 100644 index 000000000..e611a6d91 --- /dev/null +++ b/Documentation/usb/gadget_printer.rst @@ -0,0 +1,523 @@ +=============================== +Linux USB Printer Gadget Driver +=============================== + +06/04/2007 + +Copyright (C) 2007 Craig W. Nadler <craig@nadler.us> + + + +General +======= + +This driver may be used if you are writing printer firmware using Linux as +the embedded OS. This driver has nothing to do with using a printer with +your Linux host system. + +You will need a USB device controller and a Linux driver for it that accepts +a gadget / "device class" driver using the Linux USB Gadget API. After the +USB device controller driver is loaded then load the printer gadget driver. +This will present a printer interface to the USB Host that your USB Device +port is connected to. + +This driver is structured for printer firmware that runs in user mode. The +user mode printer firmware will read and write data from the kernel mode +printer gadget driver using a device file. The printer returns a printer status +byte when the USB HOST sends a device request to get the printer status. The +user space firmware can read or write this status byte using a device file +/dev/g_printer . Both blocking and non-blocking read/write calls are supported. + + + + +Howto Use This Driver +===================== + +To load the USB device controller driver and the printer gadget driver. The +following example uses the Netchip 2280 USB device controller driver:: + + modprobe net2280 + modprobe g_printer + + +The follow command line parameter can be used when loading the printer gadget +(ex: modprobe g_printer idVendor=0x0525 idProduct=0xa4a8 ): + +idVendor + This is the Vendor ID used in the device descriptor. The default is + the Netchip vendor id 0x0525. YOU MUST CHANGE TO YOUR OWN VENDOR ID + BEFORE RELEASING A PRODUCT. If you plan to release a product and don't + already have a Vendor ID please see www.usb.org for details on how to + get one. + +idProduct + This is the Product ID used in the device descriptor. The default + is 0xa4a8, you should change this to an ID that's not used by any of + your other USB products if you have any. It would be a good idea to + start numbering your products starting with say 0x0001. + +bcdDevice + This is the version number of your product. It would be a good idea + to put your firmware version here. + +iManufacturer + A string containing the name of the Vendor. + +iProduct + A string containing the Product Name. + +iSerialNum + A string containing the Serial Number. This should be changed for + each unit of your product. + +iPNPstring + The PNP ID string used for this printer. You will want to set + either on the command line or hard code the PNP ID string used for + your printer product. + +qlen + The number of 8k buffers to use per endpoint. The default is 10, you + should tune this for your product. You may also want to tune the + size of each buffer for your product. + + + + +Using The Example Code +====================== + +This example code talks to stdout, instead of a print engine. + +To compile the test code below: + +1) save it to a file called prn_example.c +2) compile the code with the follow command:: + + gcc prn_example.c -o prn_example + + + +To read printer data from the host to stdout:: + + # prn_example -read_data + + +To write printer data from a file (data_file) to the host:: + + # cat data_file | prn_example -write_data + + +To get the current printer status for the gadget driver::: + + # prn_example -get_status + + Printer status is: + Printer is NOT Selected + Paper is Out + Printer OK + + +To set printer to Selected/On-line:: + + # prn_example -selected + + +To set printer to Not Selected/Off-line:: + + # prn_example -not_selected + + +To set paper status to paper out:: + + # prn_example -paper_out + + +To set paper status to paper loaded:: + + # prn_example -paper_loaded + + +To set error status to printer OK:: + + # prn_example -no_error + + +To set error status to ERROR:: + + # prn_example -error + + + + +Example Code +============ + +:: + + + #include <stdio.h> + #include <stdlib.h> + #include <fcntl.h> + #include <linux/poll.h> + #include <sys/ioctl.h> + #include <linux/usb/g_printer.h> + + #define PRINTER_FILE "/dev/g_printer" + #define BUF_SIZE 512 + + + /* + * 'usage()' - Show program usage. + */ + + static void + usage(const char *option) /* I - Option string or NULL */ + { + if (option) { + fprintf(stderr,"prn_example: Unknown option \"%s\"!\n", + option); + } + + fputs("\n", stderr); + fputs("Usage: prn_example -[options]\n", stderr); + fputs("Options:\n", stderr); + fputs("\n", stderr); + fputs("-get_status Get the current printer status.\n", stderr); + fputs("-selected Set the selected status to selected.\n", stderr); + fputs("-not_selected Set the selected status to NOT selected.\n", + stderr); + fputs("-error Set the error status to error.\n", stderr); + fputs("-no_error Set the error status to NO error.\n", stderr); + fputs("-paper_out Set the paper status to paper out.\n", stderr); + fputs("-paper_loaded Set the paper status to paper loaded.\n", + stderr); + fputs("-read_data Read printer data from driver.\n", stderr); + fputs("-write_data Write printer sata to driver.\n", stderr); + fputs("-NB_read_data (Non-Blocking) Read printer data from driver.\n", + stderr); + fputs("\n\n", stderr); + + exit(1); + } + + + static int + read_printer_data() + { + struct pollfd fd[1]; + + /* Open device file for printer gadget. */ + fd[0].fd = open(PRINTER_FILE, O_RDWR); + if (fd[0].fd < 0) { + printf("Error %d opening %s\n", fd[0].fd, PRINTER_FILE); + close(fd[0].fd); + return(-1); + } + + fd[0].events = POLLIN | POLLRDNORM; + + while (1) { + static char buf[BUF_SIZE]; + int bytes_read; + int retval; + + /* Wait for up to 1 second for data. */ + retval = poll(fd, 1, 1000); + + if (retval && (fd[0].revents & POLLRDNORM)) { + + /* Read data from printer gadget driver. */ + bytes_read = read(fd[0].fd, buf, BUF_SIZE); + + if (bytes_read < 0) { + printf("Error %d reading from %s\n", + fd[0].fd, PRINTER_FILE); + close(fd[0].fd); + return(-1); + } else if (bytes_read > 0) { + /* Write data to standard OUTPUT (stdout). */ + fwrite(buf, 1, bytes_read, stdout); + fflush(stdout); + } + + } + + } + + /* Close the device file. */ + close(fd[0].fd); + + return 0; + } + + + static int + write_printer_data() + { + struct pollfd fd[1]; + + /* Open device file for printer gadget. */ + fd[0].fd = open (PRINTER_FILE, O_RDWR); + if (fd[0].fd < 0) { + printf("Error %d opening %s\n", fd[0].fd, PRINTER_FILE); + close(fd[0].fd); + return(-1); + } + + fd[0].events = POLLOUT | POLLWRNORM; + + while (1) { + int retval; + static char buf[BUF_SIZE]; + /* Read data from standard INPUT (stdin). */ + int bytes_read = fread(buf, 1, BUF_SIZE, stdin); + + if (!bytes_read) { + break; + } + + while (bytes_read) { + + /* Wait for up to 1 second to sent data. */ + retval = poll(fd, 1, 1000); + + /* Write data to printer gadget driver. */ + if (retval && (fd[0].revents & POLLWRNORM)) { + retval = write(fd[0].fd, buf, bytes_read); + if (retval < 0) { + printf("Error %d writing to %s\n", + fd[0].fd, + PRINTER_FILE); + close(fd[0].fd); + return(-1); + } else { + bytes_read -= retval; + } + + } + + } + + } + + /* Wait until the data has been sent. */ + fsync(fd[0].fd); + + /* Close the device file. */ + close(fd[0].fd); + + return 0; + } + + + static int + read_NB_printer_data() + { + int fd; + static char buf[BUF_SIZE]; + int bytes_read; + + /* Open device file for printer gadget. */ + fd = open(PRINTER_FILE, O_RDWR|O_NONBLOCK); + if (fd < 0) { + printf("Error %d opening %s\n", fd, PRINTER_FILE); + close(fd); + return(-1); + } + + while (1) { + /* Read data from printer gadget driver. */ + bytes_read = read(fd, buf, BUF_SIZE); + if (bytes_read <= 0) { + break; + } + + /* Write data to standard OUTPUT (stdout). */ + fwrite(buf, 1, bytes_read, stdout); + fflush(stdout); + } + + /* Close the device file. */ + close(fd); + + return 0; + } + + + static int + get_printer_status() + { + int retval; + int fd; + + /* Open device file for printer gadget. */ + fd = open(PRINTER_FILE, O_RDWR); + if (fd < 0) { + printf("Error %d opening %s\n", fd, PRINTER_FILE); + close(fd); + return(-1); + } + + /* Make the IOCTL call. */ + retval = ioctl(fd, GADGET_GET_PRINTER_STATUS); + if (retval < 0) { + fprintf(stderr, "ERROR: Failed to set printer status\n"); + return(-1); + } + + /* Close the device file. */ + close(fd); + + return(retval); + } + + + static int + set_printer_status(unsigned char buf, int clear_printer_status_bit) + { + int retval; + int fd; + + retval = get_printer_status(); + if (retval < 0) { + fprintf(stderr, "ERROR: Failed to get printer status\n"); + return(-1); + } + + /* Open device file for printer gadget. */ + fd = open(PRINTER_FILE, O_RDWR); + + if (fd < 0) { + printf("Error %d opening %s\n", fd, PRINTER_FILE); + close(fd); + return(-1); + } + + if (clear_printer_status_bit) { + retval &= ~buf; + } else { + retval |= buf; + } + + /* Make the IOCTL call. */ + if (ioctl(fd, GADGET_SET_PRINTER_STATUS, (unsigned char)retval)) { + fprintf(stderr, "ERROR: Failed to set printer status\n"); + return(-1); + } + + /* Close the device file. */ + close(fd); + + return 0; + } + + + static int + display_printer_status() + { + char printer_status; + + printer_status = get_printer_status(); + if (printer_status < 0) { + fprintf(stderr, "ERROR: Failed to get printer status\n"); + return(-1); + } + + printf("Printer status is:\n"); + if (printer_status & PRINTER_SELECTED) { + printf(" Printer is Selected\n"); + } else { + printf(" Printer is NOT Selected\n"); + } + if (printer_status & PRINTER_PAPER_EMPTY) { + printf(" Paper is Out\n"); + } else { + printf(" Paper is Loaded\n"); + } + if (printer_status & PRINTER_NOT_ERROR) { + printf(" Printer OK\n"); + } else { + printf(" Printer ERROR\n"); + } + + return(0); + } + + + int + main(int argc, char *argv[]) + { + int i; /* Looping var */ + int retval = 0; + + /* No Args */ + if (argc == 1) { + usage(0); + exit(0); + } + + for (i = 1; i < argc && !retval; i ++) { + + if (argv[i][0] != '-') { + continue; + } + + if (!strcmp(argv[i], "-get_status")) { + if (display_printer_status()) { + retval = 1; + } + + } else if (!strcmp(argv[i], "-paper_loaded")) { + if (set_printer_status(PRINTER_PAPER_EMPTY, 1)) { + retval = 1; + } + + } else if (!strcmp(argv[i], "-paper_out")) { + if (set_printer_status(PRINTER_PAPER_EMPTY, 0)) { + retval = 1; + } + + } else if (!strcmp(argv[i], "-selected")) { + if (set_printer_status(PRINTER_SELECTED, 0)) { + retval = 1; + } + + } else if (!strcmp(argv[i], "-not_selected")) { + if (set_printer_status(PRINTER_SELECTED, 1)) { + retval = 1; + } + + } else if (!strcmp(argv[i], "-error")) { + if (set_printer_status(PRINTER_NOT_ERROR, 1)) { + retval = 1; + } + + } else if (!strcmp(argv[i], "-no_error")) { + if (set_printer_status(PRINTER_NOT_ERROR, 0)) { + retval = 1; + } + + } else if (!strcmp(argv[i], "-read_data")) { + if (read_printer_data()) { + retval = 1; + } + + } else if (!strcmp(argv[i], "-write_data")) { + if (write_printer_data()) { + retval = 1; + } + + } else if (!strcmp(argv[i], "-NB_read_data")) { + if (read_NB_printer_data()) { + retval = 1; + } + + } else { + usage(argv[i]); + retval = 1; + } + } + + exit(retval); + } diff --git a/Documentation/usb/gadget_serial.rst b/Documentation/usb/gadget_serial.rst new file mode 100644 index 000000000..dce8bc1fb --- /dev/null +++ b/Documentation/usb/gadget_serial.rst @@ -0,0 +1,289 @@ +=============================== +Linux Gadget Serial Driver v2.0 +=============================== + +11/20/2004 + +(updated 8-May-2008 for v2.3) + + +License and Disclaimer +---------------------- +This program is free software; you can redistribute it and/or +modify it under the terms of the GNU General Public License as +published by the Free Software Foundation; either version 2 of +the License, or (at your option) any later version. + +This program is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public +License along with this program; if not, write to the Free +Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, +MA 02111-1307 USA. + +This document and the gadget serial driver itself are +Copyright (C) 2004 by Al Borchers (alborchers@steinerpoint.com). + +If you have questions, problems, or suggestions for this driver +please contact Al Borchers at alborchers@steinerpoint.com. + + +Prerequisites +------------- +Versions of the gadget serial driver are available for the +2.4 Linux kernels, but this document assumes you are using +version 2.3 or later of the gadget serial driver in a 2.6 +Linux kernel. + +This document assumes that you are familiar with Linux and +Windows and know how to configure and build Linux kernels, run +standard utilities, use minicom and HyperTerminal, and work with +USB and serial devices. It also assumes you configure the Linux +gadget and usb drivers as modules. + +With version 2.3 of the driver, major and minor device nodes are +no longer statically defined. Your Linux based system should mount +sysfs in /sys, and use "mdev" (in Busybox) or "udev" to make the +/dev nodes matching the sysfs /sys/class/tty files. + + + +Overview +-------- +The gadget serial driver is a Linux USB gadget driver, a USB device +side driver. It runs on a Linux system that has USB device side +hardware; for example, a PDA, an embedded Linux system, or a PC +with a USB development card. + +The gadget serial driver talks over USB to either a CDC ACM driver +or a generic USB serial driver running on a host PC:: + + Host + -------------------------------------- + | Host-Side CDC ACM USB Host | + | Operating | or | Controller | USB + | System | Generic USB | Driver |-------- + | (Linux or | Serial | and | | + | Windows) Driver USB Stack | | + -------------------------------------- | + | + | + | + Gadget | + -------------------------------------- | + | Gadget USB Periph. | | + | Device-Side | Gadget | Controller | | + | Linux | Serial | Driver |-------- + | Operating | Driver | and | + | System USB Stack | + -------------------------------------- + +On the device-side Linux system, the gadget serial driver looks +like a serial device. + +On the host-side system, the gadget serial device looks like a +CDC ACM compliant class device or a simple vendor specific device +with bulk in and bulk out endpoints, and it is treated similarly +to other serial devices. + +The host side driver can potentially be any ACM compliant driver +or any driver that can talk to a device with a simple bulk in/out +interface. Gadget serial has been tested with the Linux ACM driver, +the Windows usbser.sys ACM driver, and the Linux USB generic serial +driver. + +With the gadget serial driver and the host side ACM or generic +serial driver running, you should be able to communicate between +the host and the gadget side systems as if they were connected by a +serial cable. + +The gadget serial driver only provides simple unreliable data +communication. It does not yet handle flow control or many other +features of normal serial devices. + + +Installing the Gadget Serial Driver +----------------------------------- +To use the gadget serial driver you must configure the Linux gadget +side kernel for "Support for USB Gadgets", for a "USB Peripheral +Controller" (for example, net2280), and for the "Serial Gadget" +driver. All this are listed under "USB Gadget Support" when +configuring the kernel. Then rebuild and install the kernel or +modules. + +Then you must load the gadget serial driver. To load it as an +ACM device (recommended for interoperability), do this:: + + modprobe g_serial + +To load it as a vendor specific bulk in/out device, do this:: + + modprobe g_serial use_acm=0 + +This will also automatically load the underlying gadget peripheral +controller driver. This must be done each time you reboot the gadget +side Linux system. You can add this to the start up scripts, if +desired. + +Your system should use mdev (from busybox) or udev to make the +device nodes. After this gadget driver has been set up you should +then see a /dev/ttyGS0 node:: + + # ls -l /dev/ttyGS0 | cat + crw-rw---- 1 root root 253, 0 May 8 14:10 /dev/ttyGS0 + # + +Note that the major number (253, above) is system-specific. If +you need to create /dev nodes by hand, the right numbers to use +will be in the /sys/class/tty/ttyGS0/dev file. + +When you link this gadget driver early, perhaps even statically, +you may want to set up an /etc/inittab entry to run "getty" on it. +The /dev/ttyGS0 line should work like most any other serial port. + + +If gadget serial is loaded as an ACM device you will want to use +either the Windows or Linux ACM driver on the host side. If gadget +serial is loaded as a bulk in/out device, you will want to use the +Linux generic serial driver on the host side. Follow the appropriate +instructions below to install the host side driver. + + +Installing the Windows Host ACM Driver +-------------------------------------- +To use the Windows ACM driver you must have the "linux-cdc-acm.inf" +file (provided along this document) which supports all recent versions +of Windows. + +When the gadget serial driver is loaded and the USB device connected +to the Windows host with a USB cable, Windows should recognize the +gadget serial device and ask for a driver. Tell Windows to find the +driver in the folder that contains the "linux-cdc-acm.inf" file. + +For example, on Windows XP, when the gadget serial device is first +plugged in, the "Found New Hardware Wizard" starts up. Select +"Install from a list or specific location (Advanced)", then on the +next screen select "Include this location in the search" and enter the +path or browse to the folder containing the "linux-cdc-acm.inf" file. +Windows will complain that the Gadget Serial driver has not passed +Windows Logo testing, but select "Continue anyway" and finish the +driver installation. + +On Windows XP, in the "Device Manager" (under "Control Panel", +"System", "Hardware") expand the "Ports (COM & LPT)" entry and you +should see "Gadget Serial" listed as the driver for one of the COM +ports. + +To uninstall the Windows XP driver for "Gadget Serial", right click +on the "Gadget Serial" entry in the "Device Manager" and select +"Uninstall". + + +Installing the Linux Host ACM Driver +------------------------------------ +To use the Linux ACM driver you must configure the Linux host side +kernel for "Support for Host-side USB" and for "USB Modem (CDC ACM) +support". + +Once the gadget serial driver is loaded and the USB device connected +to the Linux host with a USB cable, the host system should recognize +the gadget serial device. For example, the command:: + + cat /sys/kernel/debug/usb/devices + +should show something like this::: + + T: Bus=01 Lev=01 Prnt=01 Port=01 Cnt=02 Dev#= 5 Spd=480 MxCh= 0 + D: Ver= 2.00 Cls=02(comm.) Sub=00 Prot=00 MxPS=64 #Cfgs= 1 + P: Vendor=0525 ProdID=a4a7 Rev= 2.01 + S: Manufacturer=Linux 2.6.8.1 with net2280 + S: Product=Gadget Serial + S: SerialNumber=0 + C:* #Ifs= 2 Cfg#= 2 Atr=c0 MxPwr= 2mA + I: If#= 0 Alt= 0 #EPs= 1 Cls=02(comm.) Sub=02 Prot=01 Driver=acm + E: Ad=83(I) Atr=03(Int.) MxPS= 8 Ivl=32ms + I: If#= 1 Alt= 0 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=acm + E: Ad=81(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms + E: Ad=02(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms + +If the host side Linux system is configured properly, the ACM driver +should be loaded automatically. The command "lsmod" should show the +"acm" module is loaded. + + +Installing the Linux Host Generic USB Serial Driver +--------------------------------------------------- +To use the Linux generic USB serial driver you must configure the +Linux host side kernel for "Support for Host-side USB", for "USB +Serial Converter support", and for the "USB Generic Serial Driver". + +Once the gadget serial driver is loaded and the USB device connected +to the Linux host with a USB cable, the host system should recognize +the gadget serial device. For example, the command:: + + cat /sys/kernel/debug/usb/devices + +should show something like this::: + + T: Bus=01 Lev=01 Prnt=01 Port=01 Cnt=02 Dev#= 6 Spd=480 MxCh= 0 + D: Ver= 2.00 Cls=ff(vend.) Sub=00 Prot=00 MxPS=64 #Cfgs= 1 + P: Vendor=0525 ProdID=a4a6 Rev= 2.01 + S: Manufacturer=Linux 2.6.8.1 with net2280 + S: Product=Gadget Serial + S: SerialNumber=0 + C:* #Ifs= 1 Cfg#= 1 Atr=c0 MxPwr= 2mA + I: If#= 0 Alt= 0 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=serial + E: Ad=81(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms + E: Ad=02(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms + +You must load the usbserial driver and explicitly set its parameters +to configure it to recognize the gadget serial device, like this:: + + echo 0x0525 0xA4A6 >/sys/bus/usb-serial/drivers/generic/new_id + +The legacy way is to use module parameters:: + + modprobe usbserial vendor=0x0525 product=0xA4A6 + +If everything is working, usbserial will print a message in the +system log saying something like "Gadget Serial converter now +attached to ttyUSB0". + + +Testing with Minicom or HyperTerminal +------------------------------------- +Once the gadget serial driver and the host driver are both installed, +and a USB cable connects the gadget device to the host, you should +be able to communicate over USB between the gadget and host systems. +You can use minicom or HyperTerminal to try this out. + +On the gadget side run "minicom -s" to configure a new minicom +session. Under "Serial port setup" set "/dev/ttygserial" as the +"Serial Device". Set baud rate, data bits, parity, and stop bits, +to 9600, 8, none, and 1--these settings mostly do not matter. +Under "Modem and dialing" erase all the modem and dialing strings. + +On a Linux host running the ACM driver, configure minicom similarly +but use "/dev/ttyACM0" as the "Serial Device". (If you have other +ACM devices connected, change the device name appropriately.) + +On a Linux host running the USB generic serial driver, configure +minicom similarly, but use "/dev/ttyUSB0" as the "Serial Device". +(If you have other USB serial devices connected, change the device +name appropriately.) + +On a Windows host configure a new HyperTerminal session to use the +COM port assigned to Gadget Serial. The "Port Settings" will be +set automatically when HyperTerminal connects to the gadget serial +device, so you can leave them set to the default values--these +settings mostly do not matter. + +With minicom configured and running on the gadget side and with +minicom or HyperTerminal configured and running on the host side, +you should be able to send data back and forth between the gadget +side and host side systems. Anything you type on the terminal +window on the gadget side should appear in the terminal window on +the host side and vice versa. diff --git a/Documentation/usb/index.rst b/Documentation/usb/index.rst new file mode 100644 index 000000000..b656c9be2 --- /dev/null +++ b/Documentation/usb/index.rst @@ -0,0 +1,38 @@ +=========== +USB support +=========== + +.. toctree:: + :maxdepth: 1 + + acm + authorization + chipidea + dwc3 + ehci + functionfs + gadget_configfs + gadget_hid + gadget_multi + gadget_printer + gadget_serial + gadget-testing + iuu_phoenix + mass-storage + misc_usbsevseg + mtouchusb + ohci + raw-gadget + usbip_protocol + usbmon + usb-serial + + usb-help + text_files + +.. only:: subproject and html + + Indices + ======= + + * :ref:`genindex` diff --git a/Documentation/usb/iuu_phoenix.rst b/Documentation/usb/iuu_phoenix.rst new file mode 100644 index 000000000..b76268728 --- /dev/null +++ b/Documentation/usb/iuu_phoenix.rst @@ -0,0 +1,94 @@ +============================= +Infinity Usb Unlimited Readme +============================= + +Hi all, + + +This module provide a serial interface to use your +IUU unit in phoenix mode. Loading this module will +bring a ttyUSB[0-x] interface. This driver must be +used by your favorite application to pilot the IUU + +This driver is still in beta stage, so bugs can +occur and your system may freeze. As far I now, +I never had any problem with it, but I'm not a real +guru, so don't blame me if your system is unstable + +You can plug more than one IUU. Every unit will +have his own device file(/dev/ttyUSB0,/dev/ttyUSB1,...) + + + +How to tune the reader speed? +============================= + + A few parameters can be used at load time + To use parameters, just unload the module if it is + already loaded and use modprobe iuu_phoenix param=value. + In case of prebuilt module, use the command + insmod iuu_phoenix param=value. + + Example:: + + modprobe iuu_phoenix clockmode=3 + + The parameters are: + +clockmode: + 1=3Mhz579,2=3Mhz680,3=6Mhz (int) +boost: + overclock boost percent 100 to 500 (int) +cdmode: + Card detect mode + 0=none, 1=CD, 2=!CD, 3=DSR, 4=!DSR, 5=CTS, 6=!CTS, 7=RING, 8=!RING (int) +xmas: + xmas color enabled or not (bool) +debug: + Debug enabled or not (bool) + +- clockmode will provide 3 different base settings commonly adopted by + different software: + + 1. 3Mhz579 + 2. 3Mhz680 + 3. 6Mhz + +- boost provide a way to overclock the reader ( my favorite :-) ) + For example to have best performance than a simple clockmode=3, try this:: + + modprobe boost=195 + + This will put the reader in a base of 3Mhz579 but boosted a 195 % ! + the real clock will be now : 6979050 Hz ( 6Mhz979 ) and will increase + the speed to a score 10 to 20% better than the simple clockmode=3 !!! + + +- cdmode permit to setup the signal used to inform the userland ( ioctl answer ) + if the card is present or not. Eight signals are possible. + +- xmas is completely useless except for your eyes. This is one of my friend who was + so sad to have a nice device like the iuu without seeing all color range available. + So I have added this option to permit him to see a lot of color ( each activity change the color + and the frequency randomly ) + +- debug will produce a lot of debugging messages... + + +Last notes +========== + + Don't worry about the serial settings, the serial emulation + is an abstraction, so use any speed or parity setting will + work. ( This will not change anything ).Later I will perhaps + use this settings to deduce de boost but is that feature + really necessary ? + The autodetect feature used is the serial CD. If that doesn't + work for your software, disable detection mechanism in it. + + + Have fun ! + + Alain Degreffe + + eczema(at)ecze.com diff --git a/Documentation/usb/linux-cdc-acm.inf b/Documentation/usb/linux-cdc-acm.inf new file mode 100644 index 000000000..f0ffc27d4 --- /dev/null +++ b/Documentation/usb/linux-cdc-acm.inf @@ -0,0 +1,107 @@ +; Windows USB CDC ACM Setup File + +; Based on INF template which was: +; Copyright (c) 2000 Microsoft Corporation +; Copyright (c) 2007 Microchip Technology Inc. +; likely to be covered by the MLPL as found at: +; <http://msdn.microsoft.com/en-us/cc300389.aspx#MLPL>. +; For use only on Windows operating systems. + +[Version] +Signature="$Windows NT$" +Class=Ports +ClassGuid={4D36E978-E325-11CE-BFC1-08002BE10318} +Provider=%Linux% +DriverVer=11/15/2007,5.1.2600.0 + +[Manufacturer] +%Linux%=DeviceList, NTamd64 + +[DestinationDirs] +DefaultDestDir=12 + + +;------------------------------------------------------------------------------ +; Windows 2000/XP/Vista-32bit Sections +;------------------------------------------------------------------------------ + +[DriverInstall.nt] +include=mdmcpq.inf +CopyFiles=DriverCopyFiles.nt +AddReg=DriverInstall.nt.AddReg + +[DriverCopyFiles.nt] +usbser.sys,,,0x20 + +[DriverInstall.nt.AddReg] +HKR,,DevLoader,,*ntkern +HKR,,NTMPDriver,,USBSER.sys +HKR,,EnumPropPages32,,"MsPorts.dll,SerialPortPropPageProvider" + +[DriverInstall.nt.Services] +AddService=usbser, 0x00000002, DriverService.nt + +[DriverService.nt] +DisplayName=%SERVICE% +ServiceType=1 +StartType=3 +ErrorControl=1 +ServiceBinary=%12%\USBSER.sys + +;------------------------------------------------------------------------------ +; Vista-64bit Sections +;------------------------------------------------------------------------------ + +[DriverInstall.NTamd64] +include=mdmcpq.inf +CopyFiles=DriverCopyFiles.NTamd64 +AddReg=DriverInstall.NTamd64.AddReg + +[DriverCopyFiles.NTamd64] +USBSER.sys,,,0x20 + +[DriverInstall.NTamd64.AddReg] +HKR,,DevLoader,,*ntkern +HKR,,NTMPDriver,,USBSER.sys +HKR,,EnumPropPages32,,"MsPorts.dll,SerialPortPropPageProvider" + +[DriverInstall.NTamd64.Services] +AddService=usbser, 0x00000002, DriverService.NTamd64 + +[DriverService.NTamd64] +DisplayName=%SERVICE% +ServiceType=1 +StartType=3 +ErrorControl=1 +ServiceBinary=%12%\USBSER.sys + + +;------------------------------------------------------------------------------ +; Vendor and Product ID Definitions +;------------------------------------------------------------------------------ +; When developing your USB device, the VID and PID used in the PC side +; application program and the firmware on the microcontroller must match. +; Modify the below line to use your VID and PID. Use the format as shown +; below. +; Note: One INF file can be used for multiple devices with different +; VID and PIDs. For each supported device, append +; ",USB\VID_xxxx&PID_yyyy" to the end of the line. +;------------------------------------------------------------------------------ +[SourceDisksFiles] +[SourceDisksNames] +[DeviceList] +%DESCRIPTION%=DriverInstall, USB\VID_0525&PID_A4A7, USB\VID_1D6B&PID_0104&MI_02, USB\VID_1D6B&PID_0106&MI_00 + +[DeviceList.NTamd64] +%DESCRIPTION%=DriverInstall, USB\VID_0525&PID_A4A7, USB\VID_1D6B&PID_0104&MI_02, USB\VID_1D6B&PID_0106&MI_00 + + +;------------------------------------------------------------------------------ +; String Definitions +;------------------------------------------------------------------------------ +;Modify these strings to customize your device +;------------------------------------------------------------------------------ +[Strings] +Linux = "Linux Developer Community" +DESCRIPTION = "Gadget Serial" +SERVICE = "USB RS-232 Emulation Driver" diff --git a/Documentation/usb/linux.inf b/Documentation/usb/linux.inf new file mode 100644 index 000000000..c569ac6be --- /dev/null +++ b/Documentation/usb/linux.inf @@ -0,0 +1,66 @@ +; Based on template INF file found at +; <https://msdn.microsoft.com/en-us/library/ff570620.aspx> +; which was: +; Copyright (c) Microsoft Corporation +; and released under the MLPL as found at: +; <http://msdn.microsoft.com/en-us/cc300389.aspx#MLPL>. +; For use only on Windows operating systems. + +[Version] +Signature = "$Windows NT$" +Class = Net +ClassGUID = {4d36e972-e325-11ce-bfc1-08002be10318} +Provider = %Linux% +DriverVer = 06/21/2006,6.0.6000.16384 + +[Manufacturer] +%Linux% = LinuxDevices,NTx86,NTamd64,NTia64 + +; Decoration for x86 architecture +[LinuxDevices.NTx86] +%LinuxDevice% = RNDIS.NT.5.1, USB\VID_0525&PID_a4a2, USB\VID_1d6b&PID_0104&MI_00 + +; Decoration for x64 architecture +[LinuxDevices.NTamd64] +%LinuxDevice% = RNDIS.NT.5.1, USB\VID_0525&PID_a4a2, USB\VID_1d6b&PID_0104&MI_00 + +; Decoration for ia64 architecture +[LinuxDevices.NTia64] +%LinuxDevice% = RNDIS.NT.5.1, USB\VID_0525&PID_a4a2, USB\VID_1d6b&PID_0104&MI_00 + +;@@@ This is the common setting for setup +[ControlFlags] +ExcludeFromSelect=* + +; DDInstall section +; References the in-build Netrndis.inf +[RNDIS.NT.5.1] +Characteristics = 0x84 ; NCF_PHYSICAL + NCF_HAS_UI +BusType = 15 +; NEVER REMOVE THE FOLLOWING REFERENCE FOR NETRNDIS.INF +include = netrndis.inf +needs = Usb_Rndis.ndi +AddReg = Rndis_AddReg_Vista + +; DDInstal.Services section +[RNDIS.NT.5.1.Services] +include = netrndis.inf +needs = Usb_Rndis.ndi.Services + +; Optional registry settings. You can modify as needed. +[RNDIS_AddReg_Vista] +HKR, NDI\params\VistaProperty, ParamDesc, 0, %Vista_Property% +HKR, NDI\params\VistaProperty, type, 0, "edit" +HKR, NDI\params\VistaProperty, LimitText, 0, "12" +HKR, NDI\params\VistaProperty, UpperCase, 0, "1" +HKR, NDI\params\VistaProperty, default, 0, " " +HKR, NDI\params\VistaProperty, optional, 0, "1" + +; No sys copyfiles - the sys files are already in-build +; (part of the operating system). +; We do not support XP SP1-, 2003 SP1-, ME, 9x. + +[Strings] +Linux = "Linux Developer Community" +LinuxDevice = "Linux USB Ethernet/RNDIS Gadget" +Vista_Property = "Optional Vista Property" diff --git a/Documentation/usb/mass-storage.rst b/Documentation/usb/mass-storage.rst new file mode 100644 index 000000000..f399ec631 --- /dev/null +++ b/Documentation/usb/mass-storage.rst @@ -0,0 +1,243 @@ +========================= +Mass Storage Gadget (MSG) +========================= + +Overview +======== + + Mass Storage Gadget (or MSG) acts as a USB Mass Storage device, + appearing to the host as a disk or a CD-ROM drive. It supports + multiple logical units (LUNs). Backing storage for each LUN is + provided by a regular file or a block device, access can be limited + to read-only, and gadget can indicate that it is removable and/or + CD-ROM (the latter implies read-only access). + + Its requirements are modest; only a bulk-in and a bulk-out endpoint + are needed. The memory requirement amounts to two 16K buffers. + Support is included for full-speed, high-speed and SuperSpeed + operation. + + Note that the driver is slightly non-portable in that it assumes + a single memory/DMA buffer will be usable for bulk-in and bulk-out + endpoints. With most device controllers this is not an issue, but + there may be some with hardware restrictions that prevent a buffer + from being used by more than one endpoint. + + This document describes how to use the gadget from user space, its + relation to mass storage function (or MSF) and different gadgets + using it, and how it differs from File Storage Gadget (or FSG) + (which is no longer included in Linux). It will talk only briefly + about how to use MSF within composite gadgets. + +Module parameters +================= + + The mass storage gadget accepts the following mass storage specific + module parameters: + + - file=filename[,filename...] + + This parameter lists paths to files or block devices used for + backing storage for each logical unit. There may be at most + FSG_MAX_LUNS (8) LUNs set. If more files are specified, they will + be silently ignored. See also “luns” parameter. + + *BEWARE* that if a file is used as a backing storage, it may not + be modified by any other process. This is because the host + assumes the data does not change without its knowledge. It may be + read, but (if the logical unit is writable) due to buffering on + the host side, the contents are not well defined. + + The size of the logical unit will be rounded down to a full + logical block. The logical block size is 2048 bytes for LUNs + simulating CD-ROM, block size of the device if the backing file is + a block device, or 512 bytes otherwise. + + - removable=b[,b...] + + This parameter specifies whether each logical unit should be + removable. “b” here is either “y”, “Y” or “1” for true or “n”, + “N” or “0” for false. + + If this option is set for a logical unit, gadget will accept an + “eject” SCSI request (Start/Stop Unit). When it is sent, the + backing file will be closed to simulate ejection and the logical + unit will not be mountable by the host until a new backing file is + specified by userspace on the device (see “sysfs entries” + section). + + If a logical unit is not removable (the default), a backing file + must be specified for it with the “file” parameter as the module + is loaded. The same applies if the module is built in, no + exceptions. + + The default value of the flag is false, *HOWEVER* it used to be + true. This has been changed to better match File Storage Gadget + and because it seems like a saner default after all. Thus to + maintain compatibility with older kernels, it's best to specify + the default values. Also, if one relied on old default, explicit + “n” needs to be specified now. + + Note that “removable” means the logical unit's media can be + ejected or removed (as is true for a CD-ROM drive or a card + reader). It does *not* mean that the entire gadget can be + unplugged from the host; the proper term for that is + “hot-unpluggable”. + + - cdrom=b[,b...] + + This parameter specifies whether each logical unit should simulate + CD-ROM. The default is false. + + - ro=b[,b...] + + This parameter specifies whether each logical unit should be + reported as read only. This will prevent host from modifying the + backing files. + + Note that if this flag for given logical unit is false but the + backing file could not be opened in read/write mode, the gadget + will fall back to read only mode anyway. + + The default value for non-CD-ROM logical units is false; for + logical units simulating CD-ROM it is forced to true. + + - nofua=b[,b...] + + This parameter specifies whether FUA flag should be ignored in SCSI + Write10 and Write12 commands sent to given logical units. + + MS Windows mounts removable storage in “Removal optimised mode” by + default. All the writes to the media are synchronous, which is + achieved by setting the FUA (Force Unit Access) bit in SCSI + Write(10,12) commands. This forces each write to wait until the + data has actually been written out and prevents I/O requests + aggregation in block layer dramatically decreasing performance. + + Note that this may mean that if the device is powered from USB and + the user unplugs the device without unmounting it first (which at + least some Windows users do), the data may be lost. + + The default value is false. + + - luns=N + + This parameter specifies number of logical units the gadget will + have. It is limited by FSG_MAX_LUNS (8) and higher value will be + capped. + + If this parameter is provided, and the number of files specified + in “file” argument is greater then the value of “luns”, all excess + files will be ignored. + + If this parameter is not present, the number of logical units will + be deduced from the number of files specified in the “file” + parameter. If the file parameter is missing as well, one is + assumed. + + - stall=b + + Specifies whether the gadget is allowed to halt bulk endpoints. + The default is determined according to the type of USB device + controller, but usually true. + + In addition to the above, the gadget also accepts the following + parameters defined by the composite framework (they are common to + all composite gadgets so just a quick listing): + + - idVendor -- USB Vendor ID (16 bit integer) + - idProduct -- USB Product ID (16 bit integer) + - bcdDevice -- USB Device version (BCD) (16 bit integer) + - iManufacturer -- USB Manufacturer string (string) + - iProduct -- USB Product string (string) + - iSerialNumber -- SerialNumber string (sting) + +sysfs entries +============= + + For each logical unit, the gadget creates a directory in the sysfs + hierarchy. Inside of it the following three files are created: + + - file + + When read it returns the path to the backing file for the given + logical unit. If there is no backing file (possible only if the + logical unit is removable), the content is empty. + + When written into, it changes the backing file for given logical + unit. This change can be performed even if given logical unit is + not specified as removable (but that may look strange to the + host). It may fail, however, if host disallowed medium removal + with the Prevent-Allow Medium Removal SCSI command. + + - ro + + Reflects the state of ro flag for the given logical unit. It can + be read any time, and written to when there is no backing file + open for given logical unit. + + - nofua + + Reflects the state of nofua flag for given logical unit. It can + be read and written. + + - forced_eject + + When written into, it causes the backing file to be forcibly + detached from the LUN, regardless of whether the host has allowed + it. The content doesn't matter, any non-zero number of bytes + written will result in ejection. + + Can not be read. + + Other then those, as usual, the values of module parameters can be + read from /sys/module/g_mass_storage/parameters/* files. + +Other gadgets using mass storage function +========================================= + + The Mass Storage Gadget uses the Mass Storage Function to handle + mass storage protocol. As a composite function, MSF may be used by + other gadgets as well (eg. g_multi and acm_ms). + + All of the information in previous sections are valid for other + gadgets using MSF, except that support for mass storage related + module parameters may be missing, or the parameters may have + a prefix. To figure out whether any of this is true one needs to + consult the gadget's documentation or its source code. + + For examples of how to include mass storage function in gadgets, one + may take a look at mass_storage.c, acm_ms.c and multi.c (sorted by + complexity). + +Relation to file storage gadget +=============================== + + The Mass Storage Function and thus the Mass Storage Gadget has been + based on the File Storage Gadget. The difference between the two is + that MSG is a composite gadget (ie. uses the composite framework) + while file storage gadget was a traditional gadget. From userspace + point of view this distinction does not really matter, but from + kernel hacker's point of view, this means that (i) MSG does not + duplicate code needed for handling basic USB protocol commands and + (ii) MSF can be used in any other composite gadget. + + Because of that, File Storage Gadget has been removed in Linux 3.8. + All users need to transition to the Mass Storage Gadget. The two + gadgets behave mostly the same from the outside except: + + 1. In FSG the “removable” and “cdrom” module parameters set the flag + for all logical units whereas in MSG they accept a list of y/n + values for each logical unit. If one uses only a single logical + unit this does not matter, but if there are more, the y/n value + needs to be repeated for each logical unit. + + 2. FSG's “serial”, “vendor”, “product” and “release” module + parameters are handled in MSG by the composite layer's parameters + named respectively: “iSerialnumber”, “idVendor”, “idProduct” and + “bcdDevice”. + + 3. MSG does not support FSG's test mode, thus “transport”, + “protocol” and “buflen” FSG's module parameters are not + supported. MSG always uses SCSI protocol with bulk only + transport mode and 16 KiB buffers. diff --git a/Documentation/usb/misc_usbsevseg.rst b/Documentation/usb/misc_usbsevseg.rst new file mode 100644 index 000000000..6274aee08 --- /dev/null +++ b/Documentation/usb/misc_usbsevseg.rst @@ -0,0 +1,51 @@ +============================= +USB 7-Segment Numeric Display +============================= + +Manufactured by Delcom Engineering + +Device Information +------------------ +USB VENDOR_ID 0x0fc5 +USB PRODUCT_ID 0x1227 +Both the 6 character and 8 character displays have PRODUCT_ID, +and according to Delcom Engineering no queryable information +can be obtained from the device to tell them apart. + +Device Modes +------------ +By default, the driver assumes the display is only 6 characters +The mode for 6 characters is: + + MSB 0x06; LSB 0x3f + +For the 8 character display: + + MSB 0x08; LSB 0xff + +The device can accept "text" either in raw, hex, or ascii textmode. +raw controls each segment manually, +hex expects a value between 0-15 per character, +ascii expects a value between '0'-'9' and 'A'-'F'. +The default is ascii. + +Device Operation +---------------- +1. Turn on the device: + echo 1 > /sys/bus/usb/.../powered +2. Set the device's mode: + echo $mode_msb > /sys/bus/usb/.../mode_msb + echo $mode_lsb > /sys/bus/usb/.../mode_lsb +3. Set the textmode: + echo $textmode > /sys/bus/usb/.../textmode +4. set the text (for example): + echo "123ABC" > /sys/bus/usb/.../text (ascii) + echo "A1B2" > /sys/bus/usb/.../text (ascii) + echo -ne "\x01\x02\x03" > /sys/bus/usb/.../text (hex) +5. Set the decimal places. + The device has either 6 or 8 decimal points. + to set the nth decimal place calculate 10 ** n + and echo it in to /sys/bus/usb/.../decimals + To set multiple decimals points sum up each power. + For example, to set the 0th and 3rd decimal place + echo 1001 > /sys/bus/usb/.../decimals diff --git a/Documentation/usb/mtouchusb.rst b/Documentation/usb/mtouchusb.rst new file mode 100644 index 000000000..5ae1f74fe --- /dev/null +++ b/Documentation/usb/mtouchusb.rst @@ -0,0 +1,84 @@ +================ +mtouchusb driver +================ + +Changes +======= + +- 0.3 - Created based off of scanner & INSTALL from the original touchscreen + driver on freecode (http://freecode.com/projects/3mtouchscreendriver) +- Amended for linux-2.4.18, then 2.4.19 + +- 0.5 - Complete rewrite using Linux Input in 2.6.3 + Unfortunately no calibration support at this time + +- 1.4 - Multiple changes to support the EXII 5000UC and house cleaning + Changed reset from standard USB dev reset to vendor reset + Changed data sent to host from compensated to raw coordinates + Eliminated vendor/product module params + Performed multiple successful tests with an EXII-5010UC + +Supported Hardware +================== + +:: + + All controllers have the Vendor: 0x0596 & Product: 0x0001 + + + Controller Description Part Number + ------------------------------------------------------ + + USB Capacitive - Pearl Case 14-205 (Discontinued) + USB Capacitive - Black Case 14-124 (Discontinued) + USB Capacitive - No Case 14-206 (Discontinued) + + USB Capacitive - Pearl Case EXII-5010UC + USB Capacitive - Black Case EXII-5030UC + USB Capacitive - No Case EXII-5050UC + +Driver Notes +============ + +Installation is simple, you only need to add Linux Input, Linux USB, and the +driver to the kernel. The driver can also be optionally built as a module. + +This driver appears to be one of possible 2 Linux USB Input Touchscreen +drivers. Although 3M produces a binary only driver available for +download, I persist in updating this driver since I would like to use the +touchscreen for embedded apps using QTEmbedded, DirectFB, etc. So I feel the +logical choice is to use Linux Input. + +Currently there is no way to calibrate the device via this driver. Even if +the device could be calibrated, the driver pulls to raw coordinate data from +the controller. This means calibration must be performed within the +userspace. + +The controller screen resolution is now 0 to 16384 for both X and Y reporting +the raw touch data. This is the same for the old and new capacitive USB +controllers. + +Perhaps at some point an abstract function will be placed into evdev so +generic functions like calibrations, resets, and vendor information can be +requested from the userspace (And the drivers would handle the vendor specific +tasks). + +TODO +==== + +Implement a control urb again to handle requests to and from the device +such as calibration, etc once/if it becomes available. + +Disclaimer +========== + +I am not a MicroTouch/3M employee, nor have I ever been. 3M does not support +this driver! If you want touch drivers only supported within X, please go to: + +http://www.3m.com/3MTouchSystems/ + +Thanks +====== + +A huge thank you to 3M Touch Systems for the EXII-5010UC controllers for +testing! diff --git a/Documentation/usb/ohci.rst b/Documentation/usb/ohci.rst new file mode 100644 index 000000000..bb3c49719 --- /dev/null +++ b/Documentation/usb/ohci.rst @@ -0,0 +1,35 @@ +==== +OHCI +==== + +23-Aug-2002 + +The "ohci-hcd" driver is a USB Host Controller Driver (HCD) that is derived +from the "usb-ohci" driver from the 2.4 kernel series. The "usb-ohci" code +was written primarily by Roman Weissgaerber <weissg@vienna.at> but with +contributions from many others (read its copyright/licencing header). + +It supports the "Open Host Controller Interface" (OHCI), which standardizes +hardware register protocols used to talk to USB 1.1 host controllers. As +compared to the earlier "Universal Host Controller Interface" (UHCI) from +Intel, it pushes more intelligence into the hardware. USB 1.1 controllers +from vendors other than Intel and VIA generally use OHCI. + +Changes since the 2.4 kernel include + + - improved robustness; bugfixes; and less overhead + - supports the updated and simplified usbcore APIs + - interrupt transfers can be larger, and can be queued + - less code, by using the upper level "hcd" framework + - supports some non-PCI implementations of OHCI + - ... more + +The "ohci-hcd" driver handles all USB 1.1 transfer types. Transfers of all +types can be queued. That was also true in "usb-ohci", except for interrupt +transfers. Previously, using periods of one frame would risk data loss due +to overhead in IRQ processing. When interrupt transfers are queued, those +risks can be minimized by making sure the hardware always has transfers to +work on while the OS is getting around to the relevant IRQ processing. + +- David Brownell + <dbrownell@users.sourceforge.net> diff --git a/Documentation/usb/raw-gadget.rst b/Documentation/usb/raw-gadget.rst new file mode 100644 index 000000000..818a1648b --- /dev/null +++ b/Documentation/usb/raw-gadget.rst @@ -0,0 +1,94 @@ +============== +USB Raw Gadget +============== + +USB Raw Gadget is a gadget driver that gives userspace low-level control over +the gadget's communication process. + +Like any other gadget driver, Raw Gadget implements USB devices via the +USB gadget API. Unlike most gadget drivers, Raw Gadget does not implement +any concrete USB functions itself but requires userspace to do that. + +Raw Gadget is currently a strictly debugging feature and should not be used +in production. Use GadgetFS instead. + +Enabled with CONFIG_USB_RAW_GADGET. + +Comparison to GadgetFS +~~~~~~~~~~~~~~~~~~~~~~ + +Raw Gadget is similar to GadgetFS but provides more direct access to the +USB gadget layer for userspace. The key differences are: + +1. Raw Gadget passes every USB request to userspace to get a response, while + GadgetFS responds to some USB requests internally based on the provided + descriptors. Note that the UDC driver might respond to some requests on + its own and never forward them to the gadget layer. + +2. Raw Gadget allows providing arbitrary data as responses to USB requests, + while GadgetFS performs sanity checks on the provided USB descriptors. + This makes Raw Gadget suitable for fuzzing by providing malformed data as + responses to USB requests. + +3. Raw Gadget provides a way to select a UDC device/driver to bind to, + while GadgetFS currently binds to the first available UDC. This allows + having multiple Raw Gadget instances bound to different UDCs. + +4. Raw Gadget explicitly exposes information about endpoints addresses and + capabilities. This allows the user to write UDC-agnostic gadgets. + +5. Raw Gadget has an ioctl-based interface instead of a filesystem-based + one. + +Userspace interface +~~~~~~~~~~~~~~~~~~~ + +The user can interact with Raw Gadget by opening ``/dev/raw-gadget`` and +issuing ioctl calls; see the comments in include/uapi/linux/usb/raw_gadget.h +for details. Multiple Raw Gadget instances (bound to different UDCs) can be +used at the same time. + +A typical usage scenario of Raw Gadget: + +1. Create a Raw Gadget instance by opening ``/dev/raw-gadget``. +2. Initialize the instance via ``USB_RAW_IOCTL_INIT``. +3. Launch the instance with ``USB_RAW_IOCTL_RUN``. +4. In a loop issue ``USB_RAW_IOCTL_EVENT_FETCH`` to receive events from + Raw Gadget and react to those depending on what kind of USB gadget must + be implemented. + +Note that some UDC drivers have fixed addresses assigned to endpoints, and +therefore arbitrary endpoint addresses cannot be used in the descriptors. +Nevertheless, Raw Gadget provides a UDC-agnostic way to write USB gadgets. +Once ``USB_RAW_EVENT_CONNECT`` is received via ``USB_RAW_IOCTL_EVENT_FETCH``, +``USB_RAW_IOCTL_EPS_INFO`` can be used to find out information about the +endpoints that the UDC driver has. Based on that, userspace must choose UDC +endpoints for the gadget and assign addresses in the endpoint descriptors +correspondingly. + +Raw Gadget usage examples and a test suite: + +https://github.com/xairy/raw-gadget + +Internal details +~~~~~~~~~~~~~~~~ + +Every Raw Gadget endpoint read/write ioctl submits a USB request and waits +until its completion. This is done deliberately to assist with coverage-guided +fuzzing by having a single syscall fully process a single USB request. This +feature must be kept in the implementation. + +Potential future improvements +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +- Report more events (suspend, resume, etc.) through + ``USB_RAW_IOCTL_EVENT_FETCH``. + +- Support ``O_NONBLOCK`` I/O. This would be another mode of operation, where + Raw Gadget would not wait until the completion of each USB request. + +- Support USB 3 features (accept SS endpoint companion descriptor when + enabling endpoints; allow providing ``stream_id`` for bulk transfers). + +- Support ISO transfer features (expose ``frame_number`` for completed + requests). diff --git a/Documentation/usb/text_files.rst b/Documentation/usb/text_files.rst new file mode 100644 index 000000000..1c18c05c3 --- /dev/null +++ b/Documentation/usb/text_files.rst @@ -0,0 +1,23 @@ +Linux CDC ACM inf +----------------- + +.. include:: linux-cdc-acm.inf + :literal: + +Linux inf +--------- + +.. include:: linux.inf + :literal: + +USB devfs drop permissions source +--------------------------------- + +.. literalinclude:: usbdevfs-drop-permissions.c + :language: c + +Credits +------- + +.. include:: CREDITS + :literal: diff --git a/Documentation/usb/usb-help.rst b/Documentation/usb/usb-help.rst new file mode 100644 index 000000000..dc23ecd4d --- /dev/null +++ b/Documentation/usb/usb-help.rst @@ -0,0 +1,17 @@ +============== +USB references +============== + +2008-Mar-7 + +For USB help other than the readme files that are located in +`Documentation/usb/*`, see the following: + +- Linux-USB project: http://www.linux-usb.org + mirrors at http://usb.in.tum.de/linux-usb/ + and http://it.linux-usb.org +- Linux USB Guide: http://linux-usb.sourceforge.net +- Linux-USB device overview (working devices and drivers): + http://www.qbik.ch/usb/devices/ + +The Linux-USB mailing list is at linux-usb@vger.kernel.org diff --git a/Documentation/usb/usb-serial.rst b/Documentation/usb/usb-serial.rst new file mode 100644 index 000000000..69586aeb6 --- /dev/null +++ b/Documentation/usb/usb-serial.rst @@ -0,0 +1,537 @@ +========== +USB serial +========== + +Introduction +============ + + The USB serial driver currently supports a number of different USB to + serial converter products, as well as some devices that use a serial + interface from userspace to talk to the device. + + See the individual product section below for specific information about + the different devices. + + +Configuration +============= + + Currently the driver can handle up to 256 different serial interfaces at + one time. + + The major number that the driver uses is 188 so to use the driver, + create the following nodes:: + + mknod /dev/ttyUSB0 c 188 0 + mknod /dev/ttyUSB1 c 188 1 + mknod /dev/ttyUSB2 c 188 2 + mknod /dev/ttyUSB3 c 188 3 + . + . + . + mknod /dev/ttyUSB254 c 188 254 + mknod /dev/ttyUSB255 c 188 255 + + When the device is connected and recognized by the driver, the driver + will print to the system log, which node(s) the device has been bound + to. + + +Specific Devices Supported +========================== + + +ConnectTech WhiteHEAT 4 port converter +-------------------------------------- + + ConnectTech has been very forthcoming with information about their + device, including providing a unit to test with. + + The driver is officially supported by Connect Tech Inc. + http://www.connecttech.com + + For any questions or problems with this driver, please contact + Connect Tech's Support Department at support@connecttech.com + + +HandSpring Visor, Palm USB, and Clié USB driver +----------------------------------------------- + + This driver works with all HandSpring USB, Palm USB, and Sony Clié USB + devices. + + Only when the device tries to connect to the host, will the device show + up to the host as a valid USB device. When this happens, the device is + properly enumerated, assigned a port, and then communication _should_ be + possible. The driver cleans up properly when the device is removed, or + the connection is canceled on the device. + + NOTE: + This means that in order to talk to the device, the sync button must be + pressed BEFORE trying to get any program to communicate to the device. + This goes against the current documentation for pilot-xfer and other + packages, but is the only way that it will work due to the hardware + in the device. + + When the device is connected, try talking to it on the second port + (this is usually /dev/ttyUSB1 if you do not have any other usb-serial + devices in the system.) The system log should tell you which port is + the port to use for the HotSync transfer. The "Generic" port can be used + for other device communication, such as a PPP link. + + For some Sony Clié devices, /dev/ttyUSB0 must be used to talk to the + device. This is true for all OS version 3.5 devices, and most devices + that have had a flash upgrade to a newer version of the OS. See the + kernel system log for information on which is the correct port to use. + + If after pressing the sync button, nothing shows up in the system log, + try resetting the device, first a hot reset, and then a cold reset if + necessary. Some devices need this before they can talk to the USB port + properly. + + Devices that are not compiled into the kernel can be specified with module + parameters. e.g. modprobe visor vendor=0x54c product=0x66 + + There is a webpage and mailing lists for this portion of the driver at: + http://sourceforge.net/projects/usbvisor/ + + For any questions or problems with this driver, please contact Greg + Kroah-Hartman at greg@kroah.com + + +PocketPC PDA Driver +------------------- + + This driver can be used to connect to Compaq iPAQ, HP Jornada, Casio EM500 + and other PDAs running Windows CE 3.0 or PocketPC 2002 using a USB + cable/cradle. + Most devices supported by ActiveSync are supported out of the box. + For others, please use module parameters to specify the product and vendor + id. e.g. modprobe ipaq vendor=0x3f0 product=0x1125 + + The driver presents a serial interface (usually on /dev/ttyUSB0) over + which one may run ppp and establish a TCP/IP link to the PDA. Once this + is done, you can transfer files, backup, download email etc. The most + significant advantage of using USB is speed - I can get 73 to 113 + kbytes/sec for download/upload to my iPAQ. + + This driver is only one of a set of components required to utilize + the USB connection. Please visit http://synce.sourceforge.net which + contains the necessary packages and a simple step-by-step howto. + + Once connected, you can use Win CE programs like ftpView, Pocket Outlook + from the PDA and xcerdisp, synce utilities from the Linux side. + + To use Pocket IE, follow the instructions given at + http://www.tekguru.co.uk/EM500/usbtonet.htm to achieve the same thing + on Win98. Omit the proxy server part; Linux is quite capable of forwarding + packets unlike Win98. Another modification is required at least for the + iPAQ - disable autosync by going to the Start/Settings/Connections menu + and unchecking the "Automatically synchronize ..." box. Go to + Start/Programs/Connections, connect the cable and select "usbdial" (or + whatever you named your new USB connection). You should finally wind + up with a "Connected to usbdial" window with status shown as connected. + Now start up PIE and browse away. + + If it doesn't work for some reason, load both the usbserial and ipaq module + with the module parameter "debug" set to 1 and examine the system log. + You can also try soft-resetting your PDA before attempting a connection. + + Other functionality may be possible depending on your PDA. According to + Wes Cilldhaire <billybobjoehenrybob@hotmail.com>, with the Toshiba E570, + ...if you boot into the bootloader (hold down the power when hitting the + reset button, continuing to hold onto the power until the bootloader screen + is displayed), then put it in the cradle with the ipaq driver loaded, open + a terminal on /dev/ttyUSB0, it gives you a "USB Reflash" terminal, which can + be used to flash the ROM, as well as the microP code.. so much for needing + Toshiba's $350 serial cable for flashing!! :D + NOTE: This has NOT been tested. Use at your own risk. + + For any questions or problems with the driver, please contact Ganesh + Varadarajan <ganesh@veritas.com> + + +Keyspan PDA Serial Adapter +-------------------------- + + Single port DB-9 serial adapter, pushed as a PDA adapter for iMacs (mostly + sold in Macintosh catalogs, comes in a translucent white/green dongle). + Fairly simple device. Firmware is homebrew. + This driver also works for the Xircom/Entrega single port serial adapter. + + Current status: + + Things that work: + - basic input/output (tested with 'cu') + - blocking write when serial line can't keep up + - changing baud rates (up to 115200) + - getting/setting modem control pins (TIOCM{GET,SET,BIS,BIC}) + - sending break (although duration looks suspect) + + Things that don't: + - device strings (as logged by kernel) have trailing binary garbage + - device ID isn't right, might collide with other Keyspan products + - changing baud rates ought to flush tx/rx to avoid mangled half characters + + Big Things on the todo list: + - parity, 7 vs 8 bits per char, 1 or 2 stop bits + - HW flow control + - not all of the standard USB descriptors are handled: + Get_Status, Set_Feature, O_NONBLOCK, select() + + For any questions or problems with this driver, please contact Brian + Warner at warner@lothar.com + + +Keyspan USA-series Serial Adapters +---------------------------------- + + Single, Dual and Quad port adapters - driver uses Keyspan supplied + firmware and is being developed with their support. + + Current status: + + The USA-18X, USA-28X, USA-19, USA-19W and USA-49W are supported and + have been pretty thoroughly tested at various baud rates with 8-N-1 + character settings. Other character lengths and parity setups are + presently untested. + + The USA-28 isn't yet supported though doing so should be pretty + straightforward. Contact the maintainer if you require this + functionality. + + More information is available at: + + http://www.carnationsoftware.com/carnation/Keyspan.html + + For any questions or problems with this driver, please contact Hugh + Blemings at hugh@misc.nu + + +FTDI Single Port Serial Driver +------------------------------ + + This is a single port DB-25 serial adapter. + + Devices supported include: + + - TripNav TN-200 USB GPS + - Navis Engineering Bureau CH-4711 USB GPS + + For any questions or problems with this driver, please contact Bill Ryder. + + +ZyXEL omni.net lcd plus ISDN TA +------------------------------- + + This is an ISDN TA. Please report both successes and troubles to + azummo@towertech.it + + +Cypress M8 CY4601 Family Serial Driver +-------------------------------------- + + This driver was in most part developed by Neil "koyama" Whelchel. It + has been improved since that previous form to support dynamic serial + line settings and improved line handling. The driver is for the most + part stable and has been tested on an smp machine. (dual p2) + + Chipsets supported under CY4601 family: + + CY7C63723, CY7C63742, CY7C63743, CY7C64013 + + Devices supported: + + - DeLorme's USB Earthmate GPS (SiRF Star II lp arch) + - Cypress HID->COM RS232 adapter + + Note: + Cypress Semiconductor claims no affiliation with the + hid->com device. + + Most devices using chipsets under the CY4601 family should + work with the driver. As long as they stay true to the CY4601 + usbserial specification. + + Technical notes: + + The Earthmate starts out at 4800 8N1 by default... the driver will + upon start init to this setting. usbserial core provides the rest + of the termios settings, along with some custom termios so that the + output is in proper format and parsable. + + The device can be put into sirf mode by issuing NMEA command:: + + $PSRF100,<protocol>,<baud>,<databits>,<stopbits>,<parity>*CHECKSUM + $PSRF100,0,9600,8,1,0*0C + + It should then be sufficient to change the port termios to match this + to begin communicating. + + As far as I can tell it supports pretty much every sirf command as + documented online available with firmware 2.31, with some unknown + message ids. + + The hid->com adapter can run at a maximum baud of 115200bps. Please note + that the device has trouble or is incapable of raising line voltage properly. + It will be fine with null modem links, as long as you do not try to link two + together without hacking the adapter to set the line high. + + The driver is smp safe. Performance with the driver is rather low when using + it for transferring files. This is being worked on, but I would be willing to + accept patches. An urb queue or packet buffer would likely fit the bill here. + + If you have any questions, problems, patches, feature requests, etc. you can + contact me here via email: + + dignome@gmail.com + + (your problems/patches can alternately be submitted to usb-devel) + + +Digi AccelePort Driver +---------------------- + + This driver supports the Digi AccelePort USB 2 and 4 devices, 2 port + (plus a parallel port) and 4 port USB serial converters. The driver + does NOT yet support the Digi AccelePort USB 8. + + This driver works under SMP with the usb-uhci driver. It does not + work under SMP with the uhci driver. + + The driver is generally working, though we still have a few more ioctls + to implement and final testing and debugging to do. The parallel port + on the USB 2 is supported as a serial to parallel converter; in other + words, it appears as another USB serial port on Linux, even though + physically it is really a parallel port. The Digi Acceleport USB 8 + is not yet supported. + + Please contact Peter Berger (pberger@brimson.com) or Al Borchers + (alborchers@steinerpoint.com) for questions or problems with this + driver. + + +Belkin USB Serial Adapter F5U103 +-------------------------------- + + Single port DB-9/PS-2 serial adapter from Belkin with firmware by eTEK Labs. + The Peracom single port serial adapter also works with this driver, as + well as the GoHubs adapter. + + Current status: + + The following have been tested and work: + + - Baud rate 300-230400 + - Data bits 5-8 + - Stop bits 1-2 + - Parity N,E,O,M,S + - Handshake None, Software (XON/XOFF), Hardware (CTSRTS,CTSDTR) [1]_ + - Break Set and clear + - Line control Input/Output query and control [2]_ + + .. [1] + Hardware input flow control is only enabled for firmware + levels above 2.06. Read source code comments describing Belkin + firmware errata. Hardware output flow control is working for all + firmware versions. + + .. [2] + Queries of inputs (CTS,DSR,CD,RI) show the last + reported state. Queries of outputs (DTR,RTS) show the last + requested state and may not reflect current state as set by + automatic hardware flow control. + + TO DO List: + - Add true modem control line query capability. Currently tracks the + states reported by the interrupt and the states requested. + - Add error reporting back to application for UART error conditions. + - Add support for flush ioctls. + - Add everything else that is missing :) + + For any questions or problems with this driver, please contact William + Greathouse at wgreathouse@smva.com + + +Empeg empeg-car Mark I/II Driver +-------------------------------- + + This is an experimental driver to provide connectivity support for the + client synchronization tools for an Empeg empeg-car mp3 player. + + Tips: + * Don't forget to create the device nodes for ttyUSB{0,1,2,...} + * modprobe empeg (modprobe is your friend) + * emptool --usb /dev/ttyUSB0 (or whatever you named your device node) + + For any questions or problems with this driver, please contact Gary + Brubaker at xavyer@ix.netcom.com + + +MCT USB Single Port Serial Adapter U232 +--------------------------------------- + + This driver is for the MCT USB-RS232 Converter (25 pin, Model No. + U232-P25) from Magic Control Technology Corp. (there is also a 9 pin + Model No. U232-P9). More information about this device can be found at + the manufacturer's web-site: http://www.mct.com.tw. + + The driver is generally working, though it still needs some more testing. + It is derived from the Belkin USB Serial Adapter F5U103 driver and its + TODO list is valid for this driver as well. + + This driver has also been found to work for other products, which have + the same Vendor ID but different Product IDs. Sitecom's U232-P25 serial + converter uses Product ID 0x230 and Vendor ID 0x711 and works with this + driver. Also, D-Link's DU-H3SP USB BAY also works with this driver. + + For any questions or problems with this driver, please contact Wolfgang + Grandegger at wolfgang@ces.ch + + +Inside Out Networks Edgeport Driver +----------------------------------- + + This driver supports all devices made by Inside Out Networks, specifically + the following models: + + - Edgeport/4 + - Rapidport/4 + - Edgeport/4t + - Edgeport/2 + - Edgeport/4i + - Edgeport/2i + - Edgeport/421 + - Edgeport/21 + - Edgeport/8 + - Edgeport/8 Dual + - Edgeport/2D8 + - Edgeport/4D8 + - Edgeport/8i + - Edgeport/2 DIN + - Edgeport/4 DIN + - Edgeport/16 Dual + + For any questions or problems with this driver, please contact Greg + Kroah-Hartman at greg@kroah.com + + +REINER SCT cyberJack pinpad/e-com USB chipcard reader +----------------------------------------------------- + + Interface to ISO 7816 compatible contactbased chipcards, e.g. GSM SIMs. + + Current status: + + This is the kernel part of the driver for this USB card reader. + There is also a user part for a CT-API driver available. A site + for downloading is TBA. For now, you can request it from the + maintainer (linux-usb@sii.li). + + For any questions or problems with this driver, please contact + linux-usb@sii.li + + +Prolific PL2303 Driver +---------------------- + + This driver supports any device that has the PL2303 chip from Prolific + in it. This includes a number of single port USB to serial converters, + more than 70% of USB GPS devices (in 2010), and some USB UPSes. Devices + from Aten (the UC-232) and IO-Data work with this driver, as does + the DCU-11 mobile-phone cable. + + For any questions or problems with this driver, please contact Greg + Kroah-Hartman at greg@kroah.com + + +KL5KUSB105 chipset / PalmConnect USB single-port adapter +-------------------------------------------------------- + +Current status: + + The driver was put together by looking at the usb bus transactions + done by Palm's driver under Windows, so a lot of functionality is + still missing. Notably, serial ioctls are sometimes faked or not yet + implemented. Support for finding out about DSR and CTS line status is + however implemented (though not nicely), so your favorite autopilot(1) + and pilot-manager -daemon calls will work. Baud rates up to 115200 + are supported, but handshaking (software or hardware) is not, which is + why it is wise to cut down on the rate used is wise for large + transfers until this is settled. + + See http://www.uuhaus.de/linux/palmconnect.html for up-to-date + information on this driver. + +Winchiphead CH341 Driver +------------------------ + + This driver is for the Winchiphead CH341 USB-RS232 Converter. This chip + also implements an IEEE 1284 parallel port, I2C and SPI, but that is not + supported by the driver. The protocol was analyzed from the behaviour + of the Windows driver, no datasheet is available at present. + + The manufacturer's website: http://www.winchiphead.com/. + + For any questions or problems with this driver, please contact + frank@kingswood-consulting.co.uk. + +Moschip MCS7720, MCS7715 driver +------------------------------- + + These chips are present in devices sold by various manufacturers, such as Syba + and Cables Unlimited. There may be others. The 7720 provides two serial + ports, and the 7715 provides one serial and one standard PC parallel port. + Support for the 7715's parallel port is enabled by a separate option, which + will not appear unless parallel port support is first enabled at the top-level + of the Device Drivers config menu. Currently only compatibility mode is + supported on the parallel port (no ECP/EPP). + + TODO: + - Implement ECP/EPP modes for the parallel port. + - Baud rates higher than 115200 are currently broken. + - Devices with a single serial port based on the Moschip MCS7703 may work + with this driver with a simple addition to the usb_device_id table. I + don't have one of these devices, so I can't say for sure. + +Generic Serial driver +--------------------- + + If your device is not one of the above listed devices, compatible with + the above models, you can try out the "generic" interface. This + interface does not provide any type of control messages sent to the + device, and does not support any kind of device flow control. All that + is required of your device is that it has at least one bulk in endpoint, + or one bulk out endpoint. + + To enable the generic driver to recognize your device, provide:: + + echo <vid> <pid> >/sys/bus/usb-serial/drivers/generic/new_id + + where the <vid> and <pid> is replaced with the hex representation of your + device's vendor id and product id. + If the driver is compiled as a module you can also provide one id when + loading the module:: + + insmod usbserial vendor=0x#### product=0x#### + + This driver has been successfully used to connect to the NetChip USB + development board, providing a way to develop USB firmware without + having to write a custom driver. + + For any questions or problems with this driver, please contact Greg + Kroah-Hartman at greg@kroah.com + + +Contact +======= + + If anyone has any problems using these drivers, with any of the above + specified products, please contact the specific driver's author listed + above, or join the Linux-USB mailing list (information on joining the + mailing list, as well as a link to its searchable archive is at + http://www.linux-usb.org/ ) + + +Greg Kroah-Hartman +greg@kroah.com diff --git a/Documentation/usb/usbdevfs-drop-permissions.c b/Documentation/usb/usbdevfs-drop-permissions.c new file mode 100644 index 000000000..6b8da6ef0 --- /dev/null +++ b/Documentation/usb/usbdevfs-drop-permissions.c @@ -0,0 +1,120 @@ +#include <sys/ioctl.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <stdio.h> +#include <errno.h> +#include <string.h> +#include <inttypes.h> +#include <unistd.h> + +#include <linux/usbdevice_fs.h> + +/* For building without an updated set of headers */ +#ifndef USBDEVFS_DROP_PRIVILEGES +#define USBDEVFS_DROP_PRIVILEGES _IOW('U', 30, __u32) +#define USBDEVFS_CAP_DROP_PRIVILEGES 0x40 +#endif + +void drop_privileges(int fd, uint32_t mask) +{ + int res; + + res = ioctl(fd, USBDEVFS_DROP_PRIVILEGES, &mask); + if (res) + printf("ERROR: USBDEVFS_DROP_PRIVILEGES returned %d\n", res); + else + printf("OK: privileges dropped!\n"); +} + +void reset_device(int fd) +{ + int res; + + res = ioctl(fd, USBDEVFS_RESET); + if (!res) + printf("OK: USBDEVFS_RESET succeeded\n"); + else + printf("ERROR: reset failed! (%d - %s)\n", + -res, strerror(-res)); +} + +void claim_some_intf(int fd) +{ + int i, res; + + for (i = 0; i < 4; i++) { + res = ioctl(fd, USBDEVFS_CLAIMINTERFACE, &i); + if (!res) + printf("OK: claimed if %d\n", i); + else + printf("ERROR claiming if %d (%d - %s)\n", + i, -res, strerror(-res)); + } +} + +int main(int argc, char *argv[]) +{ + uint32_t mask, caps; + int c, fd; + + fd = open(argv[1], O_RDWR); + if (fd < 0) { + printf("Failed to open file\n"); + goto err_fd; + } + + /* + * check if dropping privileges is supported, + * bail on systems where the capability is not present + */ + ioctl(fd, USBDEVFS_GET_CAPABILITIES, &caps); + if (!(caps & USBDEVFS_CAP_DROP_PRIVILEGES)) { + printf("DROP_PRIVILEGES not supported\n"); + goto err; + } + + /* + * Drop privileges but keep the ability to claim all + * free interfaces (i.e., those not used by kernel drivers) + */ + drop_privileges(fd, -1U); + + printf("Available options:\n" + "[0] Exit now\n" + "[1] Reset device. Should fail if device is in use\n" + "[2] Claim 4 interfaces. Should succeed where not in use\n" + "[3] Narrow interface permission mask\n" + "Which option shall I run?: "); + + while (scanf("%d", &c) == 1) { + switch (c) { + case 0: + goto exit; + case 1: + reset_device(fd); + break; + case 2: + claim_some_intf(fd); + break; + case 3: + printf("Insert new mask: "); + scanf("%x", &mask); + drop_privileges(fd, mask); + break; + default: + printf("I don't recognize that\n"); + } + + printf("Which test shall I run next?: "); + } + +exit: + close(fd); + return 0; + +err: + close(fd); +err_fd: + return 1; +} diff --git a/Documentation/usb/usbip_protocol.rst b/Documentation/usb/usbip_protocol.rst new file mode 100644 index 000000000..adc158967 --- /dev/null +++ b/Documentation/usb/usbip_protocol.rst @@ -0,0 +1,452 @@ +=============== +USB/IP protocol +=============== + +Architecture +============ + +The USB/IP protocol follows a server/client architecture. The server exports the +USB devices and the clients import them. The device driver for the exported +USB device runs on the client machine. + +The client may ask for the list of the exported USB devices. To get the list the +client opens a TCP/IP connection to the server, and sends an OP_REQ_DEVLIST +packet on top of the TCP/IP connection (so the actual OP_REQ_DEVLIST may be sent +in one or more pieces at the low level transport layer). The server sends back +the OP_REP_DEVLIST packet which lists the exported USB devices. Finally the +TCP/IP connection is closed. + +:: + + virtual host controller usb host + "client" "server" + (imports USB devices) (exports USB devices) + | | + | OP_REQ_DEVLIST | + | ----------------------------------------------> | + | | + | OP_REP_DEVLIST | + | <---------------------------------------------- | + | | + +Once the client knows the list of exported USB devices it may decide to use one +of them. First the client opens a TCP/IP connection to the server and +sends an OP_REQ_IMPORT packet. The server replies with OP_REP_IMPORT. If the +import was successful the TCP/IP connection remains open and will be used +to transfer the URB traffic between the client and the server. The client may +send two types of packets: the USBIP_CMD_SUBMIT to submit an URB, and +USBIP_CMD_UNLINK to unlink a previously submitted URB. The answers of the +server may be USBIP_RET_SUBMIT and USBIP_RET_UNLINK respectively. + +:: + + virtual host controller usb host + "client" "server" + (imports USB devices) (exports USB devices) + | | + | OP_REQ_IMPORT | + | ----------------------------------------------> | + | | + | OP_REP_IMPORT | + | <---------------------------------------------- | + | | + | | + | USBIP_CMD_SUBMIT(seqnum = n) | + | ----------------------------------------------> | + | | + | USBIP_RET_SUBMIT(seqnum = n) | + | <---------------------------------------------- | + | . | + | : | + | | + | USBIP_CMD_SUBMIT(seqnum = m) | + | ----------------------------------------------> | + | | + | USBIP_CMD_SUBMIT(seqnum = m+1) | + | ----------------------------------------------> | + | | + | USBIP_CMD_SUBMIT(seqnum = m+2) | + | ----------------------------------------------> | + | | + | USBIP_RET_SUBMIT(seqnum = m) | + | <---------------------------------------------- | + | | + | USBIP_CMD_SUBMIT(seqnum = m+3) | + | ----------------------------------------------> | + | | + | USBIP_RET_SUBMIT(seqnum = m+1) | + | <---------------------------------------------- | + | | + | USBIP_CMD_SUBMIT(seqnum = m+4) | + | ----------------------------------------------> | + | | + | USBIP_RET_SUBMIT(seqnum = m+2) | + | <---------------------------------------------- | + | . | + | : | + +For UNLINK, note that after a successful USBIP_RET_UNLINK, the unlinked URB +submission would not have a corresponding USBIP_RET_SUBMIT (this is explained in +function stub_recv_cmd_unlink of drivers/usb/usbip/stub_rx.c). + +:: + + virtual host controller usb host + "client" "server" + (imports USB devices) (exports USB devices) + | | + | USBIP_CMD_SUBMIT(seqnum = p) | + | ----------------------------------------------> | + | | + | USBIP_CMD_UNLINK | + | (seqnum = p+1, unlink_seqnum = p) | + | ----------------------------------------------> | + | | + | USBIP_RET_UNLINK | + | (seqnum = p+1, status = -ECONNRESET) | + | <---------------------------------------------- | + | | + | Note: No USBIP_RET_SUBMIT(seqnum = p) | + | <--X---X---X---X---X---X---X---X---X---X---X--- | + | . | + | : | + | | + | USBIP_CMD_SUBMIT(seqnum = q) | + | ----------------------------------------------> | + | | + | USBIP_RET_SUBMIT(seqnum = q) | + | <---------------------------------------------- | + | | + | USBIP_CMD_UNLINK | + | (seqnum = q+1, unlink_seqnum = q) | + | ----------------------------------------------> | + | | + | USBIP_RET_UNLINK | + | (seqnum = q+1, status = 0) | + | <---------------------------------------------- | + | | + +The fields are in network (big endian) byte order meaning that the most significant +byte (MSB) is stored at the lowest address. + +Protocol Version +================ + +The documented USBIP version is v1.1.1. The binary representation of this +version in message headers is 0x0111. + +This is defined in tools/usb/usbip/configure.ac + +Message Format +============== + +OP_REQ_DEVLIST: + Retrieve the list of exported USB devices. + ++-----------+--------+------------+---------------------------------------------------+ +| Offset | Length | Value | Description | ++===========+========+============+===================================================+ +| 0 | 2 | | USBIP version | ++-----------+--------+------------+---------------------------------------------------+ +| 2 | 2 | 0x8005 | Command code: Retrieve the list of exported USB | +| | | | devices. | ++-----------+--------+------------+---------------------------------------------------+ +| 4 | 4 | 0x00000000 | Status: unused, shall be set to 0 | ++-----------+--------+------------+---------------------------------------------------+ + +OP_REP_DEVLIST: + Reply with the list of exported USB devices. + ++-----------+--------+------------+---------------------------------------------------+ +| Offset | Length | Value | Description | ++===========+========+============+===================================================+ +| 0 | 2 | | USBIP version | ++-----------+--------+------------+---------------------------------------------------+ +| 2 | 2 | 0x0005 | Reply code: The list of exported USB devices. | ++-----------+--------+------------+---------------------------------------------------+ +| 4 | 4 | 0x00000000 | Status: 0 for OK | ++-----------+--------+------------+---------------------------------------------------+ +| 8 | 4 | n | Number of exported devices: 0 means no exported | +| | | | devices. | ++-----------+--------+------------+---------------------------------------------------+ +| 0x0C | | | From now on the exported n devices are described, | +| | | | if any. If no devices are exported the message | +| | | | ends with the previous "number of exported | +| | | | devices" field. | ++-----------+--------+------------+---------------------------------------------------+ +| | 256 | | path: Path of the device on the host exporting the| +| | | | USB device, string closed with zero byte, e.g. | +| | | | "/sys/devices/pci0000:00/0000:00:1d.1/usb3/3-2" | +| | | | The unused bytes shall be filled with zero | +| | | | bytes. | ++-----------+--------+------------+---------------------------------------------------+ +| 0x10C | 32 | | busid: Bus ID of the exported device, string | +| | | | closed with zero byte, e.g. "3-2". The unused | +| | | | bytes shall be filled with zero bytes. | ++-----------+--------+------------+---------------------------------------------------+ +| 0x12C | 4 | | busnum | ++-----------+--------+------------+---------------------------------------------------+ +| 0x130 | 4 | | devnum | ++-----------+--------+------------+---------------------------------------------------+ +| 0x134 | 4 | | speed | ++-----------+--------+------------+---------------------------------------------------+ +| 0x138 | 2 | | idVendor | ++-----------+--------+------------+---------------------------------------------------+ +| 0x13A | 2 | | idProduct | ++-----------+--------+------------+---------------------------------------------------+ +| 0x13C | 2 | | bcdDevice | ++-----------+--------+------------+---------------------------------------------------+ +| 0x13E | 1 | | bDeviceClass | ++-----------+--------+------------+---------------------------------------------------+ +| 0x13F | 1 | | bDeviceSubClass | ++-----------+--------+------------+---------------------------------------------------+ +| 0x140 | 1 | | bDeviceProtocol | ++-----------+--------+------------+---------------------------------------------------+ +| 0x141 | 1 | | bConfigurationValue | ++-----------+--------+------------+---------------------------------------------------+ +| 0x142 | 1 | | bNumConfigurations | ++-----------+--------+------------+---------------------------------------------------+ +| 0x143 | 1 | | bNumInterfaces | ++-----------+--------+------------+---------------------------------------------------+ +| 0x144 | | m_0 | From now on each interface is described, all | +| | | | together bNumInterfaces times, with the following | +| | | | 4 fields: | ++-----------+--------+------------+---------------------------------------------------+ +| | 1 | | bInterfaceClass | ++-----------+--------+------------+---------------------------------------------------+ +| 0x145 | 1 | | bInterfaceSubClass | ++-----------+--------+------------+---------------------------------------------------+ +| 0x146 | 1 | | bInterfaceProtocol | ++-----------+--------+------------+---------------------------------------------------+ +| 0x147 | 1 | | padding byte for alignment, shall be set to zero | ++-----------+--------+------------+---------------------------------------------------+ +| 0xC + | | | The second exported USB device starts at i=1 | +| i*0x138 + | | | with the path field. | +| m_(i-1)*4 | | | | ++-----------+--------+------------+---------------------------------------------------+ + +OP_REQ_IMPORT: + Request to import (attach) a remote USB device. + ++-----------+--------+------------+---------------------------------------------------+ +| Offset | Length | Value | Description | ++===========+========+============+===================================================+ +| 0 | 2 | | USBIP version | ++-----------+--------+------------+---------------------------------------------------+ +| 2 | 2 | 0x8003 | Command code: import a remote USB device. | ++-----------+--------+------------+---------------------------------------------------+ +| 4 | 4 | 0x00000000 | Status: unused, shall be set to 0 | ++-----------+--------+------------+---------------------------------------------------+ +| 8 | 32 | | busid: the busid of the exported device on the | +| | | | remote host. The possible values are taken | +| | | | from the message field OP_REP_DEVLIST.busid. | +| | | | A string closed with zero, the unused bytes | +| | | | shall be filled with zeros. | ++-----------+--------+------------+---------------------------------------------------+ + +OP_REP_IMPORT: + Reply to import (attach) a remote USB device. + ++-----------+--------+------------+---------------------------------------------------+ +| Offset | Length | Value | Description | ++===========+========+============+===================================================+ +| 0 | 2 | | USBIP version | ++-----------+--------+------------+---------------------------------------------------+ +| 2 | 2 | 0x0003 | Reply code: Reply to import. | ++-----------+--------+------------+---------------------------------------------------+ +| 4 | 4 | 0x00000000 | Status: | +| | | | | +| | | | - 0 for OK | +| | | | - 1 for error | ++-----------+--------+------------+---------------------------------------------------+ +| 8 | | | From now on comes the details of the imported | +| | | | device, if the previous status field was OK (0), | +| | | | otherwise the reply ends with the status field. | ++-----------+--------+------------+---------------------------------------------------+ +| | 256 | | path: Path of the device on the host exporting the| +| | | | USB device, string closed with zero byte, e.g. | +| | | | "/sys/devices/pci0000:00/0000:00:1d.1/usb3/3-2" | +| | | | The unused bytes shall be filled with zero | +| | | | bytes. | ++-----------+--------+------------+---------------------------------------------------+ +| 0x108 | 32 | | busid: Bus ID of the exported device, string | +| | | | closed with zero byte, e.g. "3-2". The unused | +| | | | bytes shall be filled with zero bytes. | ++-----------+--------+------------+---------------------------------------------------+ +| 0x128 | 4 | | busnum | ++-----------+--------+------------+---------------------------------------------------+ +| 0x12C | 4 | | devnum | ++-----------+--------+------------+---------------------------------------------------+ +| 0x130 | 4 | | speed | ++-----------+--------+------------+---------------------------------------------------+ +| 0x134 | 2 | | idVendor | ++-----------+--------+------------+---------------------------------------------------+ +| 0x136 | 2 | | idProduct | ++-----------+--------+------------+---------------------------------------------------+ +| 0x138 | 2 | | bcdDevice | ++-----------+--------+------------+---------------------------------------------------+ +| 0x139 | 1 | | bDeviceClass | ++-----------+--------+------------+---------------------------------------------------+ +| 0x13A | 1 | | bDeviceSubClass | ++-----------+--------+------------+---------------------------------------------------+ +| 0x13B | 1 | | bDeviceProtocol | ++-----------+--------+------------+---------------------------------------------------+ +| 0x13C | 1 | | bConfigurationValue | ++-----------+--------+------------+---------------------------------------------------+ +| 0x13D | 1 | | bNumConfigurations | ++-----------+--------+------------+---------------------------------------------------+ +| 0x13E | 1 | | bNumInterfaces | ++-----------+--------+------------+---------------------------------------------------+ + +The following four commands have a common basic header called +'usbip_header_basic', and their headers, called 'usbip_header' (before +transfer_buffer payload), have the same length, therefore paddings are needed. + +usbip_header_basic: + ++-----------+--------+---------------------------------------------------+ +| Offset | Length | Description | ++===========+========+===================================================+ +| 0 | 4 | command | ++-----------+--------+---------------------------------------------------+ +| 4 | 4 | seqnum: sequential number that identifies requests| +| | | and corresponding responses; | +| | | incremented per connection | ++-----------+--------+---------------------------------------------------+ +| 8 | 4 | devid: specifies a remote USB device uniquely | +| | | instead of busnum and devnum; | +| | | for client (request), this value is | +| | | ((busnum << 16) | devnum); | +| | | for server (response), this shall be set to 0 | ++-----------+--------+---------------------------------------------------+ +| 0xC | 4 | direction: | +| | | | +| | | - 0: USBIP_DIR_OUT | +| | | - 1: USBIP_DIR_IN | +| | | | +| | | only used by client, for server this shall be 0 | ++-----------+--------+---------------------------------------------------+ +| 0x10 | 4 | ep: endpoint number | +| | | only used by client, for server this shall be 0; | +| | | for UNLINK, this shall be 0 | ++-----------+--------+---------------------------------------------------+ + +USBIP_CMD_SUBMIT: + Submit an URB + ++-----------+--------+---------------------------------------------------+ +| Offset | Length | Description | ++===========+========+===================================================+ +| 0 | 20 | usbip_header_basic, 'command' shall be 0x00000001 | ++-----------+--------+---------------------------------------------------+ +| 0x14 | 4 | transfer_flags: possible values depend on the | +| | | USBIP_URB transfer_flags. | +| | | Refer to include/uapi/linux/usbip.h and | +| | | Documentation/driver-api/usb/URB.rst. | +| | | Refer to usbip_pack_cmd_submit() and | +| | | tweak_transfer_flags() in drivers/usb/usbip/ | +| | | usbip_common.c. | ++-----------+--------+---------------------------------------------------+ +| 0x18 | 4 | transfer_buffer_length: | +| | | use URB transfer_buffer_length | ++-----------+--------+---------------------------------------------------+ +| 0x1C | 4 | start_frame: use URB start_frame; | +| | | initial frame for ISO transfer; | +| | | shall be set to 0 if not ISO transfer | ++-----------+--------+---------------------------------------------------+ +| 0x20 | 4 | number_of_packets: number of ISO packets; | +| | | shall be set to 0xffffffff if not ISO transfer | ++-----------+--------+---------------------------------------------------+ +| 0x24 | 4 | interval: maximum time for the request on the | +| | | server-side host controller | ++-----------+--------+---------------------------------------------------+ +| 0x28 | 8 | setup: data bytes for USB setup, filled with | +| | | zeros if not used. | ++-----------+--------+---------------------------------------------------+ +| 0x30 | n | transfer_buffer. | +| | | If direction is USBIP_DIR_OUT then n equals | +| | | transfer_buffer_length; otherwise n equals 0. | +| | | For ISO transfers the padding between each ISO | +| | | packets is not transmitted. | ++-----------+--------+---------------------------------------------------+ +| 0x30+n | m | iso_packet_descriptor | ++-----------+--------+---------------------------------------------------+ + +USBIP_RET_SUBMIT: + Reply for submitting an URB + ++-----------+--------+---------------------------------------------------+ +| Offset | Length | Description | ++===========+========+===================================================+ +| 0 | 20 | usbip_header_basic, 'command' shall be 0x00000003 | ++-----------+--------+---------------------------------------------------+ +| 0x14 | 4 | status: zero for successful URB transaction, | +| | | otherwise some kind of error happened. | ++-----------+--------+---------------------------------------------------+ +| 0x18 | 4 | actual_length: number of URB data bytes; | +| | | use URB actual_length | ++-----------+--------+---------------------------------------------------+ +| 0x1C | 4 | start_frame: use URB start_frame; | +| | | initial frame for ISO transfer; | +| | | shall be set to 0 if not ISO transfer | ++-----------+--------+---------------------------------------------------+ +| 0x20 | 4 | number_of_packets: number of ISO packets; | +| | | shall be set to 0xffffffff if not ISO transfer | ++-----------+--------+---------------------------------------------------+ +| 0x24 | 4 | error_count | ++-----------+--------+---------------------------------------------------+ +| 0x28 | 8 | padding, shall be set to 0 | ++-----------+--------+---------------------------------------------------+ +| 0x30 | n | transfer_buffer. | +| | | If direction is USBIP_DIR_IN then n equals | +| | | actual_length; otherwise n equals 0. | +| | | For ISO transfers the padding between each ISO | +| | | packets is not transmitted. | ++-----------+--------+---------------------------------------------------+ +| 0x30+n | m | iso_packet_descriptor | ++-----------+--------+---------------------------------------------------+ + +USBIP_CMD_UNLINK: + Unlink an URB + ++-----------+--------+---------------------------------------------------+ +| Offset | Length | Description | ++===========+========+===================================================+ +| 0 | 20 | usbip_header_basic, 'command' shall be 0x00000002 | ++-----------+--------+---------------------------------------------------+ +| 0x14 | 4 | unlink_seqnum, of the SUBMIT request to unlink | ++-----------+--------+---------------------------------------------------+ +| 0x18 | 24 | padding, shall be set to 0 | ++-----------+--------+---------------------------------------------------+ + +USBIP_RET_UNLINK: + Reply for URB unlink + ++-----------+--------+---------------------------------------------------+ +| Offset | Length | Description | ++===========+========+===================================================+ +| 0 | 20 | usbip_header_basic, 'command' shall be 0x00000004 | ++-----------+--------+---------------------------------------------------+ +| 0x14 | 4 | status: This is similar to the status of | +| | | USBIP_RET_SUBMIT (share the same memory offset). | +| | | When UNLINK is successful, status is -ECONNRESET; | +| | | when USBIP_CMD_UNLINK is after USBIP_RET_SUBMIT | +| | | status is 0 | ++-----------+--------+---------------------------------------------------+ +| 0x18 | 24 | padding, shall be set to 0 | ++-----------+--------+---------------------------------------------------+ + +EXAMPLE +======= + + The following data is captured from wire with Human Interface Devices (HID) + payload + +:: + + CmdIntrIN: 00000001 00000d05 0001000f 00000001 00000001 00000200 00000040 ffffffff 00000000 00000004 00000000 00000000 + CmdIntrOUT: 00000001 00000d06 0001000f 00000000 00000001 00000000 00000040 ffffffff 00000000 00000004 00000000 00000000 + ffffffff860008a784ce5ae212376300000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 + RetIntrOut: 00000003 00000d06 00000000 00000000 00000000 00000000 00000040 ffffffff 00000000 00000000 00000000 00000000 + RetIntrIn: 00000003 00000d05 00000000 00000000 00000000 00000000 00000040 ffffffff 00000000 00000000 00000000 00000000 + ffffffff860011a784ce5ae2123763612891b1020100000400000000000000000000000000000000000000000000000000000000000000000000000000000000 diff --git a/Documentation/usb/usbmon.rst b/Documentation/usb/usbmon.rst new file mode 100644 index 000000000..6d5ec1e62 --- /dev/null +++ b/Documentation/usb/usbmon.rst @@ -0,0 +1,375 @@ +====== +usbmon +====== + +Introduction +============ + +The name "usbmon" in lowercase refers to a facility in kernel which is +used to collect traces of I/O on the USB bus. This function is analogous +to a packet socket used by network monitoring tools such as tcpdump(1) +or Ethereal. Similarly, it is expected that a tool such as usbdump or +USBMon (with uppercase letters) is used to examine raw traces produced +by usbmon. + +The usbmon reports requests made by peripheral-specific drivers to Host +Controller Drivers (HCD). So, if HCD is buggy, the traces reported by +usbmon may not correspond to bus transactions precisely. This is the same +situation as with tcpdump. + +Two APIs are currently implemented: "text" and "binary". The binary API +is available through a character device in /dev namespace and is an ABI. +The text API is deprecated since 2.6.35, but available for convenience. + +How to use usbmon to collect raw text traces +============================================ + +Unlike the packet socket, usbmon has an interface which provides traces +in a text format. This is used for two purposes. First, it serves as a +common trace exchange format for tools while more sophisticated formats +are finalized. Second, humans can read it in case tools are not available. + +To collect a raw text trace, execute following steps. + +1. Prepare +---------- + +Mount debugfs (it has to be enabled in your kernel configuration), and +load the usbmon module (if built as module). The second step is skipped +if usbmon is built into the kernel:: + + # mount -t debugfs none_debugs /sys/kernel/debug + # modprobe usbmon + # + +Verify that bus sockets are present:: + + # ls /sys/kernel/debug/usb/usbmon + 0s 0u 1s 1t 1u 2s 2t 2u 3s 3t 3u 4s 4t 4u + # + +Now you can choose to either use the socket '0u' (to capture packets on all +buses), and skip to step #3, or find the bus used by your device with step #2. +This allows to filter away annoying devices that talk continuously. + +2. Find which bus connects to the desired device +------------------------------------------------ + +Run "cat /sys/kernel/debug/usb/devices", and find the T-line which corresponds +to the device. Usually you do it by looking for the vendor string. If you have +many similar devices, unplug one and compare the two +/sys/kernel/debug/usb/devices outputs. The T-line will have a bus number. + +Example:: + + T: Bus=03 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 2 Spd=12 MxCh= 0 + D: Ver= 1.10 Cls=00(>ifc ) Sub=00 Prot=00 MxPS= 8 #Cfgs= 1 + P: Vendor=0557 ProdID=2004 Rev= 1.00 + S: Manufacturer=ATEN + S: Product=UC100KM V2.00 + +"Bus=03" means it's bus 3. Alternatively, you can look at the output from +"lsusb" and get the bus number from the appropriate line. Example: + +Bus 003 Device 002: ID 0557:2004 ATEN UC100KM V2.00 + +3. Start 'cat' +-------------- + +:: + + # cat /sys/kernel/debug/usb/usbmon/3u > /tmp/1.mon.out + +to listen on a single bus, otherwise, to listen on all buses, type:: + + # cat /sys/kernel/debug/usb/usbmon/0u > /tmp/1.mon.out + +This process will read until it is killed. Naturally, the output can be +redirected to a desirable location. This is preferred, because it is going +to be quite long. + +4. Perform the desired operation on the USB bus +----------------------------------------------- + +This is where you do something that creates the traffic: plug in a flash key, +copy files, control a webcam, etc. + +5. Kill cat +----------- + +Usually it's done with a keyboard interrupt (Control-C). + +At this point the output file (/tmp/1.mon.out in this example) can be saved, +sent by e-mail, or inspected with a text editor. In the last case make sure +that the file size is not excessive for your favourite editor. + +Raw text data format +==================== + +Two formats are supported currently: the original, or '1t' format, and +the '1u' format. The '1t' format is deprecated in kernel 2.6.21. The '1u' +format adds a few fields, such as ISO frame descriptors, interval, etc. +It produces slightly longer lines, but otherwise is a perfect superset +of '1t' format. + +If it is desired to recognize one from the other in a program, look at the +"address" word (see below), where '1u' format adds a bus number. If 2 colons +are present, it's the '1t' format, otherwise '1u'. + +Any text format data consists of a stream of events, such as URB submission, +URB callback, submission error. Every event is a text line, which consists +of whitespace separated words. The number or position of words may depend +on the event type, but there is a set of words, common for all types. + +Here is the list of words, from left to right: + +- URB Tag. This is used to identify URBs, and is normally an in-kernel address + of the URB structure in hexadecimal, but can be a sequence number or any + other unique string, within reason. + +- Timestamp in microseconds, a decimal number. The timestamp's resolution + depends on available clock, and so it can be much worse than a microsecond + (if the implementation uses jiffies, for example). + +- Event Type. This type refers to the format of the event, not URB type. + Available types are: S - submission, C - callback, E - submission error. + +- "Address" word (formerly a "pipe"). It consists of four fields, separated by + colons: URB type and direction, Bus number, Device address, Endpoint number. + Type and direction are encoded with two bytes in the following manner: + + == == ============================= + Ci Co Control input and output + Zi Zo Isochronous input and output + Ii Io Interrupt input and output + Bi Bo Bulk input and output + == == ============================= + + Bus number, Device address, and Endpoint are decimal numbers, but they may + have leading zeros, for the sake of human readers. + +- URB Status word. This is either a letter, or several numbers separated + by colons: URB status, interval, start frame, and error count. Unlike the + "address" word, all fields save the status are optional. Interval is printed + only for interrupt and isochronous URBs. Start frame is printed only for + isochronous URBs. Error count is printed only for isochronous callback + events. + + The status field is a decimal number, sometimes negative, which represents + a "status" field of the URB. This field makes no sense for submissions, but + is present anyway to help scripts with parsing. When an error occurs, the + field contains the error code. + + In case of a submission of a Control packet, this field contains a Setup Tag + instead of an group of numbers. It is easy to tell whether the Setup Tag is + present because it is never a number. Thus if scripts find a set of numbers + in this word, they proceed to read Data Length (except for isochronous URBs). + If they find something else, like a letter, they read the setup packet before + reading the Data Length or isochronous descriptors. + +- Setup packet, if present, consists of 5 words: one of each for bmRequestType, + bRequest, wValue, wIndex, wLength, as specified by the USB Specification 2.0. + These words are safe to decode if Setup Tag was 's'. Otherwise, the setup + packet was present, but not captured, and the fields contain filler. + +- Number of isochronous frame descriptors and descriptors themselves. + If an Isochronous transfer event has a set of descriptors, a total number + of them in an URB is printed first, then a word per descriptor, up to a + total of 5. The word consists of 3 colon-separated decimal numbers for + status, offset, and length respectively. For submissions, initial length + is reported. For callbacks, actual length is reported. + +- Data Length. For submissions, this is the requested length. For callbacks, + this is the actual length. + +- Data tag. The usbmon may not always capture data, even if length is nonzero. + The data words are present only if this tag is '='. + +- Data words follow, in big endian hexadecimal format. Notice that they are + not machine words, but really just a byte stream split into words to make + it easier to read. Thus, the last word may contain from one to four bytes. + The length of collected data is limited and can be less than the data length + reported in the Data Length word. In the case of an Isochronous input (Zi) + completion where the received data is sparse in the buffer, the length of + the collected data can be greater than the Data Length value (because Data + Length counts only the bytes that were received whereas the Data words + contain the entire transfer buffer). + +Examples: + +An input control transfer to get a port status:: + + d5ea89a0 3575914555 S Ci:1:001:0 s a3 00 0000 0003 0004 4 < + d5ea89a0 3575914560 C Ci:1:001:0 0 4 = 01050000 + +An output bulk transfer to send a SCSI command 0x28 (READ_10) in a 31-byte +Bulk wrapper to a storage device at address 5:: + + dd65f0e8 4128379752 S Bo:1:005:2 -115 31 = 55534243 ad000000 00800000 80010a28 20000000 20000040 00000000 000000 + dd65f0e8 4128379808 C Bo:1:005:2 0 31 > + +Raw binary format and API +========================= + +The overall architecture of the API is about the same as the one above, +only the events are delivered in binary format. Each event is sent in +the following structure (its name is made up, so that we can refer to it):: + + struct usbmon_packet { + u64 id; /* 0: URB ID - from submission to callback */ + unsigned char type; /* 8: Same as text; extensible. */ + unsigned char xfer_type; /* ISO (0), Intr, Control, Bulk (3) */ + unsigned char epnum; /* Endpoint number and transfer direction */ + unsigned char devnum; /* Device address */ + u16 busnum; /* 12: Bus number */ + char flag_setup; /* 14: Same as text */ + char flag_data; /* 15: Same as text; Binary zero is OK. */ + s64 ts_sec; /* 16: gettimeofday */ + s32 ts_usec; /* 24: gettimeofday */ + int status; /* 28: */ + unsigned int length; /* 32: Length of data (submitted or actual) */ + unsigned int len_cap; /* 36: Delivered length */ + union { /* 40: */ + unsigned char setup[SETUP_LEN]; /* Only for Control S-type */ + struct iso_rec { /* Only for ISO */ + int error_count; + int numdesc; + } iso; + } s; + int interval; /* 48: Only for Interrupt and ISO */ + int start_frame; /* 52: For ISO */ + unsigned int xfer_flags; /* 56: copy of URB's transfer_flags */ + unsigned int ndesc; /* 60: Actual number of ISO descriptors */ + }; /* 64 total length */ + +These events can be received from a character device by reading with read(2), +with an ioctl(2), or by accessing the buffer with mmap. However, read(2) +only returns first 48 bytes for compatibility reasons. + +The character device is usually called /dev/usbmonN, where N is the USB bus +number. Number zero (/dev/usbmon0) is special and means "all buses". +Note that specific naming policy is set by your Linux distribution. + +If you create /dev/usbmon0 by hand, make sure that it is owned by root +and has mode 0600. Otherwise, unprivileged users will be able to snoop +keyboard traffic. + +The following ioctl calls are available, with MON_IOC_MAGIC 0x92: + + MON_IOCQ_URB_LEN, defined as _IO(MON_IOC_MAGIC, 1) + +This call returns the length of data in the next event. Note that majority of +events contain no data, so if this call returns zero, it does not mean that +no events are available. + + MON_IOCG_STATS, defined as _IOR(MON_IOC_MAGIC, 3, struct mon_bin_stats) + +The argument is a pointer to the following structure:: + + struct mon_bin_stats { + u32 queued; + u32 dropped; + }; + +The member "queued" refers to the number of events currently queued in the +buffer (and not to the number of events processed since the last reset). + +The member "dropped" is the number of events lost since the last call +to MON_IOCG_STATS. + + MON_IOCT_RING_SIZE, defined as _IO(MON_IOC_MAGIC, 4) + +This call sets the buffer size. The argument is the size in bytes. +The size may be rounded down to the next chunk (or page). If the requested +size is out of [unspecified] bounds for this kernel, the call fails with +-EINVAL. + + MON_IOCQ_RING_SIZE, defined as _IO(MON_IOC_MAGIC, 5) + +This call returns the current size of the buffer in bytes. + + MON_IOCX_GET, defined as _IOW(MON_IOC_MAGIC, 6, struct mon_get_arg) + MON_IOCX_GETX, defined as _IOW(MON_IOC_MAGIC, 10, struct mon_get_arg) + +These calls wait for events to arrive if none were in the kernel buffer, +then return the first event. The argument is a pointer to the following +structure:: + + struct mon_get_arg { + struct usbmon_packet *hdr; + void *data; + size_t alloc; /* Length of data (can be zero) */ + }; + +Before the call, hdr, data, and alloc should be filled. Upon return, the area +pointed by hdr contains the next event structure, and the data buffer contains +the data, if any. The event is removed from the kernel buffer. + +The MON_IOCX_GET copies 48 bytes to hdr area, MON_IOCX_GETX copies 64 bytes. + + MON_IOCX_MFETCH, defined as _IOWR(MON_IOC_MAGIC, 7, struct mon_mfetch_arg) + +This ioctl is primarily used when the application accesses the buffer +with mmap(2). Its argument is a pointer to the following structure:: + + struct mon_mfetch_arg { + uint32_t *offvec; /* Vector of events fetched */ + uint32_t nfetch; /* Number of events to fetch (out: fetched) */ + uint32_t nflush; /* Number of events to flush */ + }; + +The ioctl operates in 3 stages. + +First, it removes and discards up to nflush events from the kernel buffer. +The actual number of events discarded is returned in nflush. + +Second, it waits for an event to be present in the buffer, unless the pseudo- +device is open with O_NONBLOCK. + +Third, it extracts up to nfetch offsets into the mmap buffer, and stores +them into the offvec. The actual number of event offsets is stored into +the nfetch. + + MON_IOCH_MFLUSH, defined as _IO(MON_IOC_MAGIC, 8) + +This call removes a number of events from the kernel buffer. Its argument +is the number of events to remove. If the buffer contains fewer events +than requested, all events present are removed, and no error is reported. +This works when no events are available too. + + FIONBIO + +The ioctl FIONBIO may be implemented in the future, if there's a need. + +In addition to ioctl(2) and read(2), the special file of binary API can +be polled with select(2) and poll(2). But lseek(2) does not work. + +* Memory-mapped access of the kernel buffer for the binary API + +The basic idea is simple: + +To prepare, map the buffer by getting the current size, then using mmap(2). +Then, execute a loop similar to the one written in pseudo-code below:: + + struct mon_mfetch_arg fetch; + struct usbmon_packet *hdr; + int nflush = 0; + for (;;) { + fetch.offvec = vec; // Has N 32-bit words + fetch.nfetch = N; // Or less than N + fetch.nflush = nflush; + ioctl(fd, MON_IOCX_MFETCH, &fetch); // Process errors, too + nflush = fetch.nfetch; // This many packets to flush when done + for (i = 0; i < nflush; i++) { + hdr = (struct ubsmon_packet *) &mmap_area[vec[i]]; + if (hdr->type == '@') // Filler packet + continue; + caddr_t data = &mmap_area[vec[i]] + 64; + process_packet(hdr, data); + } + } + +Thus, the main idea is to execute only one ioctl per N events. + +Although the buffer is circular, the returned headers and data do not cross +the end of the buffer, so the above pseudo-code does not need any gathering. |