Am Dienstag, 2. Dezember 2003 19:16 schrieb Dimitris Lampridis: > Hi guys, > this is my first post in this list, so I would like to thank anyone and > all of you in advance for your past, current and future help. > > My goal is to write a HCD for the USB sub-system of a PowerPC > architecture (some embedded device). This system is based on the ISP116x > USB controller by Philips.
Are you sure nobody has already done it? > So, if I'm understanding what I've been reading for some time now, I'm > gonna have to write something similar to the usb-ohci driver (since the > controller is designed based on OHCI, with some differences). This > "ohci-like" driver should communicate with usbcore(?) to provide some > standard functions required by every HCD, so that usbcore in turn, > provide these functions to usb devices. > > If the above is right, then my choice of currently reading OHCI specs > and the usb-ohci code of the kernel (2.4.22) is good(?) I think. But i'm > finding it very hard to follow the code of usb-ohci (it will take me > propably some months to REALLY understand what's going on in there). Yes, but an HCD driver has further functions. > Thus, to end this long e-mail, I was wondering if there is another > solution to reading the whole code, something like a description of the > API that the kernel requires by every HCD or anything else that you > think that reading it is going to help me. I know of no formal description. The first thing to look at would be include/linux/usb.h :: struct usb_operations These define communication in direction of usbcore->hcd driver An hcd driver talks to usbcore in the other direction to register controllers with usbcore. Your driver also talks to device drivers via calling completion handlers. Error codes for this are documented on http://www.linux-usb.org Also note that completion handlers must be called with irqs off. Furthermore you must emulate a virtual root hub in your driver. HTH Oliver ------------------------------------------------------- This SF.net email is sponsored by OSDN's Audience Survey. Help shape OSDN's sites and tell us what you think. Take this five minute survey and you could win a $250 Gift Certificate. http://www.wrgsurveys.com/2003/osdntech03.php?site=8 _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
