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USS720 driver
The USS720 is a USB to Parallel port chip made by Lucent that normally acts like a USB Printer Class device. Indeed you can use a USS720 based bridge and a parallel port printer with the USB Printer driver, (see above). However there is also a mode (known as register mode) which makes the USS720 look like normal parallel port hardware. This driver makes use of that mode.
/proc/sys/dev/parport before you load the
module or reboot with a kernel with USS720 enabled. You should note
the number of parallel ports you have - typically one, under
/proc/sys/dev/parport/parport0. After you put
USS720 support into your kernel, you should have another port (perhaps
/proc/sys/dev/parport1). If you look at the
appropriate hardware entry, you should see
something like the following:
[bradh@rachel bradh]$ more /proc/sys/dev/parport/parport1/hardware base: 0x0 irq: none dma: none modes: PCSPP,TRISTATE,COMPAT,EPP,ECP |
Every distribution should have device node entries
for parallel ports - typically /dev/lpX or
/dev/parX, where the X
is some number. If you need to create them, parallel ports device nodes
use character major number 6.
You should now be able to use the USS720 for anything that you would
normally need a parallel port for, except that certain timing sensitive
applications may not work, since the emulation is rather slow.
As for a real USB printer, I suggest use of automated tools to generate a
/etc/printcap entry if you are connecting up a
printer.
If you didn't get to select USS720 support at the configuration stage,
you need to turn on Parallel port support
support (under General setup if using
menuconfig).