Alan Stern <[EMAIL PROTECTED]> wrote: > On Thu, 18 Aug 2005, Uwe Bonnes wrote:
> > However for mapping the interrupt mechanism available in the parport > > framework to the USB layer I have no idea. In basic, the status register > > of the SJA1000 needs to be polled at a high rate.1000 Hz would probably > > do, like the time frame for non Full spped USB devices use. > Is that a typo? 1000 Hz _is_ the frame rate for full-speed USB. > (High-speed USB uses microframes at 8000 Hz.) Hence a full-speed device > with an interrupt endpoint whose period was 1 frame would be interrogated > 1000 times per second. No, not a typo. With every frame, I would like to send a USB command initiating a read of the interrupt status register of the SJA1000 and read the data send from the device with the read initiated in the frame before. But data to the FT2232 is transferred via bulk endpoints. No interrupt endpoints are available with the FT2232. > > When a certain > > condition is met, the USB layer needs to react appropriate and needs to > > inform higher levels. > That will happen whenever the device sends a positive response to the > periodic interrogation. The low level layer has to decipher the data read from the interrupt status register and only inform the upper levels if something interesting has happened. > > Is there already something like a parport framework for the USB layer? I > > know about libusb, but it is in user space and has therefore some > > drawbacks but also some advantages... > I'm not aware of anything like that. You may end up with no choice but to > build your own tools. I was afraid of that :-( -- Uwe Bonnes [EMAIL PROTECTED] Institut fuer Kernphysik Schlossgartenstrasse 9 64289 Darmstadt --------- Tel. 06151 162516 -------- Fax. 06151 164321 ---------- ------------------------------------------------------- SF.Net email is Sponsored by the Better Software Conference & EXPO September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
