Hi, > I knew that a ehci controller is often combined with a gadget > controller to get otg support. What I didn't know is that it's always > the same gadget controller. Currently we have not less than 4 drivers > for the same hardware in the tree: > > langwell_udc.c > mv_udc_core.c > ci13xxx_udc.c > fsl_udc_core.c Yes, I reported it some time ago : http://marc.info/?l=linux-usb&m=129751953620076&w=2 > Altogether there seems to be enough room for merging code. > Unfortunately I won't have much time to work on this, so I'd like to > ask if anyone else is interested in joining forces to get some > cleanup done. I am interested, but I don't too much time either. What I planned to do was to make fsl_udc_core generic : - extract probe/remove/suspend/resume platform stuff in platform driver. The core is generic like host ehci (and some flags if needed). - provide a callback for post reset (ulpi stuff) - handle strange clock handling (pre and post) I started to do something, but I never found time to finish it. > > At least I think we should pick one of the drivers above, sort the > architecture specfic part out and rename it to something like > ehci_udc.c to prevent people from adding even more drivers to the > tree. The ci13xxx_udc driver looks most promising to me as it already > has otg support in drivers/usb/otg/msm72k_otg.c and has proven to > work on i.MX aswell. Also it has pci support. Originally it was > posted for mips, so it probably works there, too I think the ci13xxx_udc code is not the best. It is not tested very well, the original code was pci (for eval board) no otg. Msm did their driver (http://marc.info/?t=128930153200003&r=1&w=2) and I recommended them to use the in kernel driver. At that time I didn't know of fsl driver and only though there was ci13xxx_udc driver for ehci udc. What a same. If they used fsl one, things will be much simpler. So ci13xxx_udc is only used by msm, and they start cleaning the code. The mips version got some bugs/missing features [1]. For example the hardware queuing (http://marc.info/?l=linux-usb&m=129803121032245&w=2) that is already in fsl driver for years is a newer feature of the driver. Also ci13xxx_udc use features not available on all core ( http://www.nxp.com/documents/user_manual/UM10314.pdf USBADRA of DEVICEADDR). For me the best candidate are fsl one or langwell : - fsl_udc_core is the historic driver and seems to have tested pretty well (and was used on big/little endian arch). Know to work on older cores. - langwell_udc is pretty active one and got otg support (and lpm). But ATM it work only with lpm core (the register layout change). I hope we could find a way to merge them. Matthieu PS : tegra2 chip use the fsl udc driver with some ifdef in the android repo. [1 ]http://marc.info/?a=128333220800005&r=1&w=2 -- 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
