On 8 Jul 2003 at 20:50, Oliver Neukum wrote: > Am Dienstag, 8. Juli 2003 18:23 schrieb [EMAIL PROTECTED]: > > Hello all, > > > > I'm setting up a device driver for a GPIB (IEEE-488) interface. > > GPIB is a General-Purpose Interface Bus (hence the name) which > > enables connection of arbitrary peripherals to a PC. It's used > > primarily to support automated test facilities in manufacturing > > environments. > > I am remembering C-128 right now :-) > > > Each interface can support up to 30 peripheral devices (hard limit > > per the GPIB spec), which can include hard drives, keyboards, > > printers, etc. My design will support up to eight interfaces > > (arbitrary limit). > > Have a look at > http://linux-gpib.sourceforge.net/ > But they might not be what you need. >
I've already looked at that, and it doesn't seem to support the USB complexity. It's just generic GPIB. > > I need to map peripherals to user-visible nodes like /dev/prn0 or > > /dev/usb/prn0. I don't know how to register the driver for these > > Don't drag USB into this. There's no reason to specify how the > bus is connected to the host. The cleanest way to do this is to get a > GPIB major number. > That seems like a cleaner way to do it. Hide the USB connectivity from the user. But there's still the problem of hotplugging. > > nodes since the configuration is defined by user software. The only > > access to the driver from user space appears to be through the > > open() or ioctl() functions, but the driver must already be > > registered for a node before being called. Seems to be a > > chicken-and-egg problem ??? > > If you wish to export all a bus's devices to user space, you might > just as well register 2**5 devices per GPIB bus. Could you state your > problem more clearly? > Clarity is actually the essence of the problem. Each system will be different, and each user will likely have many different system configurations, which could change many times per day. I have no control over the configuration. I have to support whatever the client chooses to define. > > Also, these mappings must persist through unplugging and replugging > > of interfaces, regardless of the order in which this is done, since > > the external bus is hard-wired. > > Almost impossible unless you can tell GPIB adapters apart. > I can identify them by serial number. > Regards > Oliver > Thanks very much. Any further suggestions would be welcome. Leigh Bassett ------------------------------------------------------- This SF.Net email sponsored by: Parasoft Error proof Web apps, automate testing & more. Download & eval WebKing and get a free book. www.parasoft.com/bulletproofapps _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
