Hi Hans, On Fri, Feb 13, 2015 at 08:25:46PM +0100, Hans de Goede wrote: > I'm happy to report that after a lot of poking at the Allwinner > musb code I've it working reliable in both host and peripheral mode, > as well as automatically switching between the 2 depending on which > cable gets plugged. > > My wip code is available here: > > https://github.com/jwrdegoede/linux-sunxi/commits/sunxi-wip > > Functionality wise this is complete and I expect / hope there will be > no functional changes before it goes upstream. > > There are 2 things which need to be done before it can be submitted > upstream though: > > 1) All the ForceVbus / ForceID stuff needs to be cleaned up > 2) Currently this is not suitable for multiplatform kernels as it > puts a #ifdef MACH_SUNXI in musb_regs.h, this needs to be fixed. > > 1) is just a matter of removing a whole lot of unnecessary indirection > in the code, and giving the relevant defines better names > 2) I've a plan for, I just need some time for this. > > I've so far only tested this on a cubietruck, I started development on > a cubieboard, but the cubieboard has the Vusb hardwired to the 5V of the > board (or at least mine does) meaning that the Vusb enable gpio does not > do anything, and Vusb-detect always reads as 1, I think my current code > may work despite this, but I need to test. > > Note that the dts modifications for the cubietruck / cubieboard enable > the musb controller in otg mode, which means that it will not "start" > until a gadget driver is loaded. For testing I use: > > insmod libcomposite.ko > insmod u_serial.ko > insmod usb_f_acm.ko > insmod g_serial.ko > > After this you should see 2 messages like this: > > [ 3528.872816] g_serial gadget: Gadget Serial v2.4 > [ 3528.877377] g_serial gadget: g_serial ready > > And then the controller should work either as a usb serial > port (ttyGS0 on cubietruck side, ttyACM0 on pc version) > or as a usb host, depending on what you plug in, and you should > be able to switch on the fly. > > I use the following on the cubietruck side to start a getty > on the usb serial, this assumes you use systemd :) > > systemctl start [email protected] > > If you put this in say rc.local, then you can use it to > get a console on a tablet over the otg connector, which is > very useful for debugging stuff.
Very nice, thanks! Last time I tried musb, there was some issue with the switch from host to peripheral after a random number of switches. Did you encounter such a thing during your tests? Maxime -- Maxime Ripard, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
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