On Wed, 30 Jul 2003, David Brownell wrote: > > That is, an ioctl call provides > > the gadget driver with a descriptor for a block device or a regular file, > > which the driver then uses. (Also, that means I can just copy the loop > > driver code :-) > > A module parameter could be even simpler. Eventually those are > supposed to show up in sysfs, and there's no confusion about > initialization: the parameter is available before the driver > binds to the controller. Which is good, since as soon as it > successfully binds, the gadget driver must be fully functional...
I take your point. Using a module parameter does appear to be the simplest solution. > > Doing the same thing via sysfs would come down to having a writeable > > attribute file where a user process could place a pathname for the > > device/file. It ought to work just as well, assuming that gadgets are > > registered in the sysfs file system. > > I have a patch, not yet submitted, that makes the gadget controller > appear as a sysfs class -- exactly like Greg's "usb_host" class, > with the debug files sitting there. It's done for net2280, and > likely the pxa2xx_udc will choose the same answer ... though I may > first rip out the class support, it doesn't seem useful. > > The gadget itself is a child of the controller, just like the root > hub is (on the host side). You can certainly assume the gadget > will appear in sysfs. But it won't be accessible to the gadget > driver until after binding, which means it can't be used for any > information that's needed to initialize any device configurations. > > It'd be more useful to you maybe if gadget _drivers_ were in sysfs. > But that can't be done without a sysfs "bus", it seems. That's sort of what I had in mind. But you must already have a bus available -- how is the USB controller connected? With a net2280, for instance, presumably it's a device on the PCI bus. The gadget could be a child of the controller, and that would give you a place for the driver. Another project for the future, perhaps? Alan Stern ------------------------------------------------------- This SF.Net email sponsored by: Free pre-built ASP.NET sites including Data Reports, E-commerce, Portals, and Forums are available now. Download today and enter to win an XBOX or Visual Studio .NET. http://aspnet.click-url.com/go/psa00100003ave/direct;at.aspnet_072303_01/01 _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
