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From: Brad.Hards@dao.defence.gov.au
To: linux-usb@suse.com
Date: Tue, 8 Jun 1999 08:47:46 +1000
Subject: [linux-usb] HOW-TO USB 0.3 [15K]
I have reorganised the HOWTO, guessed at a few things, and built it up. This is
mostly a "send corrections" version (odd number minor version). Probably better
not archived. Please send me corrections for printer, acm, and cpia since I
don't have those, and I just guessed how it might work.
I will fix the X - mouse problem in the next version, after I get it the wheel
stuff incorporated and try out my second mouse.
(See attached file: HOWTO-usb-0.3.tar.gz)
_______________________________________________
How to get USB devices working under Linux
Brad Hards
$Revision: 0.3 $
This document is an early draft a step-by-step guide to getting USB
devices working on a linux system
_________________________________________________________________
Basic USB Configuration
You need a late version kernel. Kernel versions 2.2.7 and later
contain the USB code. You really need to be running the current 2.3.x
kernel, ideally with any pre-patches for the next kernel. USB code is
in fairly early development, so the changes between each version (and
the bugs) tend to change fairly fast. Support on the mailing list
linux-usb@suse.com for anything except the lastest version is scant at
best.
You need to configure USB into your kernel. Use of make menuconfig is
recommended. Under USB drivers - not for the faint of heart , you need
to select Support for USB (EXPERIMENTAL!) . You also need to select
one of UHCI (intel PIIX4 and others) support, OHCI (compaq and some
others) support or OHCI-HCD (other OHCI opt. Virt. Root Hub) support.
Use of more than one of UHCI, OHCI, and OHCI-HCD at the same time is
not expected to fully work (UHCI might work). Which one you select is
dependent on what kind of motherboard or adapter you have. Intel and
Via motherboards are UHCI. Compaq and NEC motherboards, iMacs and any
adapter using Opti chips (just about all of them) are OHCI, and you
can use OHCI or OHCI-HCD, at your option. If you do not know what kind
of controller to choose, check your motherboard documentation or look
at /proc/pci for a hint. Failing that, just try one.
You also need to select whichever devices you want to use, for example
USB mouse support for a USB mouse, USB keyboard support for a USB
keyboard, USB hub support for a hub, USB Abstract Control Model
support for a POTS or ISDN modem, and Preliminary USB Printer support
for a USB printer. You should be able to use modules or split modules
and kernel code.
Rebuild the kernel and the modules (if you configured to build as
modules), and install the new kernel and the new modules. Reboot the
system. You need to install usb modules with modprobe usb-uhci ,
modprobe usb-ohci or modprobe usb-ohci-hcd if you elected to build as
modules.
Inspect the kernel logs. You should see lines like the following
(assuming use of OHCI-HCD)
May 14 09:29:41 rachel kernel: USB HID boot protocol mouse registered.
....
May 14 09:29:41 rachel kernel: usb_hub_thread at c01b68ec
May 14 09:29:41 rachel kernel: ohci_roothub_thread at c01b523c
....
May 14 09:29:41 rachel kernel: USB mouse found
UHCI and OHCI should give similar results. You may also see lines
about hub configuration (if you have one) and descriptors. Don't worry
about failing transfers, this is a minor bug that shouldn't affect
anything. If there isn't anything that could be USB related (lines
that mention hubs, usb, ohci or uhci), likely causes are use of the
wrong driver (UHCI when you needed OHCI or OHCI when you needed UHCI),
not physically installing the hardware, a BIOS configuration that
disables USB or stuffing up the configuration or installation of the
kernel.
_________________________________________________________________
Mouse Configuration
Firstly check that your mouse is being correctly sensed by the kernel.
If you type more /proc/interrupts , you should see a line that refers
to USB - typically ohci-usb or usb . If you click the mouse a few
times, and then have a look at /proc/interrupts the count associated
should increase (by two per click, one for down and one for up). This
may not work reliably if you have other devices connected, notably a
keyboard.
You need to set up a /dev entry for the mouse. Use the following
command:
mknod /dev/usbmouse c 10 32
Check /proc/misc. You should see something like
[bradh@rachel bradh]$ more /proc/misc
32 USB Mouse
1 psaux
If you want to use the mouse under X, you need to:
* edit the XF86Config file (usually /usr/X11R6/lib/X11/XF86Config).
Add the following (anywhere sensible, ideally in the Input devices
area).
Section "Xinput"
SubSection "Mouse"
DeviceName "USB Mouse"
Protocol "PS/2"
Port "/dev/usbmouse"
AlwaysCore
EndSubSection
EndSection
* Restart the X server. If you don't have any mouse support at this
point, remember that Ctrl-Alt-1 will get you a virtual terminal
that you can use to kill the xserver and start debugging from the
error messages
If you want to use the mouse under gpm, run gpm -m /dev/usbmouse -t
ps2 (as superuser remember). You can make this the default if you edit
the rc.d file(s) in /etc/rc.d/
_________________________________________________________________
Keyboard Configuration
You may not need any operating system support at all to use a USB
keyboard. There are several BIOSs available where the BIOS can provide
USB support from a keyboard plugged into the root hub on the
motherboard. This is not expected to work though other hubs or on
add-in boards, so you might want to add in support anyway.
Check that your keyboard is being correctly sensed by the kernel. If
you type more /proc/interrupts , you should see a line that refers to
USB - typically ohci-usb or usb . If you type on the keyboards and
then have a look at /proc/interrupts the count associated should
increase.
At this point, you should be able to use your USB keyboard just as for
a normal keyboard. Be aware that LILO is not USB aware, and that
unless your BIOS supports a USB keyboard, you may not be able to
select a non-default boot image using the USB keyboard.
_________________________________________________________________
Hub Support
Hubs should work without other configuration.
_________________________________________________________________
Printer Support
You need to set up a /dev entry for the printer. Use the following
command:
mknod /dev/usblp c 254 0
You should now be able to use this device in a normal /etc/printcap
entry. I recommend use of automated tools to generate such files, such
as RedHat's control panel print-tool.
_________________________________________________________________
Abstract Control Model Support
You need to set up a /dev entry for the ACM device. Use the following
command:
mknod /dev/usbacm c 10 32
You should now be able to use a terminal emulator program to attach to
this /dev/usbacm and connect to your modem or other terminal device.
_________________________________________________________________
CPiA imager support
Support for CPiA cameras is included in the normal distribution, but
is not included in the normal Config.in in the linux/drivers/usb
directory. You need to add a line like
dep_tristate 'USB CPiA camera support' CONFIG_USB_CPIA $CONFIG_USB
into this Config.in. Now reconfigure your kernel to support this
device and also enable Video For Linux support (under Character
Devices if using menuconfig.
You need to set up a /dev entry for the CPiA camera. Use the following
command:
mknod /dev/usbacm c 81 0
_________________________________________________________________
Corrections
Please send comments on this document to the author, preferably by
E-Mail (<[1]brad.hards@dao.defence.gov.au>), including the version
number: ($Revision: 0.1 $).
References
1. mailto:brad.hards@dao.defence.gov.au