On Mon, 6 Jul 2009, Sylvain PORTES wrote: > Hello, > > I am very new to Linux Kernel framework. > > All I did is an adaptation of an existing driver (LegoTower) for my > specific application it was working well until I had to add an other > communication endpoints pair. > > I am now dealing with the problem of accessing to two endpoints with > the same driver. Why is that a problem? Lots of other drivers do it. > I found several tricks : > > using IOCtrl but I still have the problem of multi threaded access, > > then I thought to adding a "trick" like : first byte of writing > indicates which endpoint shall be written and the read data the first > byte is indicating where the data comes from but the I feel it is not > the good way to do. > > Then I thought multiple dev could be the solution, I browsed the usb > kernel driver sources but it seems that the rule is one dev per device > driver. No, a driver can manage multiple devices. However it is most unusual (probably never occurs at all) for multiple drivers to manage a single device. Why do you need multiple drivers? Why can't you write a single driver that handles several endpoints? > So I start working on Linux-usb mailing list archives. Then I found > evocation of usbfs2 which seems to be exactly what I need. usbfs2 doesn't exist. It is "vaporware". > I looked for documentation, I saw the vid of Sarah presentation (very > impressive) and started to get her sources from her git. > I am not a specialist of Git either but basically what I got is an > image of Kernel Src. Browsing exchange about "multiple devices for one > Usb interface" topic in archives, I noticed an email from Sarah which > mentionned her code was in the file : "drivers/usb/core/endpoint_ > fops.c" > But I don't have it in the files I cloned from sarah git. > > So my question is simple, is there an HOW TO use usbfs2 ? > Is there a documentation about usbfs2 which explains how it's work > and what shall be done to make it acceptable to the main kernel tree. There is no documentation and there is no code. Perhaps Sarah has written some stuff and not made it available, but even if she has, it will be very incomplete. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
