On Fri, Nov 30 2012, Felipe Balbi wrote: > Hi, > > On Thu, Nov 29, 2012 at 05:43:21PM +0100, Sebastian Andrzej Siewior wrote: >> |# modprobe dummy_hcd num=2 >> >> |# find /sys/kernel/config/ -ls >> >> | 557 0 drwxr-xr-x 3 root root 0 Nov 29 17:26 /sys/kernel/config/ >> | 558 0 drwxr-xr-x 5 root root 0 Nov 29 17:26 /sys/kernel/config/usb_gadget >> | 561 0 drwxr-xr-x 4 root root 0 Nov 29 17:26 /sys/kernel/config/usb_gadget/udcs >> | 569 0 drwxr-xr-x 2 root root 0 Nov 29 17:26 /sys/kernel/config/usb_gadget/udcs/dummy_udc.1 >> | 568 0 drwxr-xr-x 2 root root 0 Nov 29 17:26 /sys/kernel/config/usb_gadget/udcs/dummy_udc.0 >> | 560 0 drwxr-xr-x 2 root root 0 Nov 29 17:26 /sys/kernel/config/usb_gadget/gadgets >> | 559 0 drwxr-xr-x 2 root root 0 Nov 29 17:26 /sys/kernel/config/usb_gadget/functions >> >> | # lsmod >> | Module Size Used by >> | dummy_hcd 20287 0 >> | udc 10219 1 dummy_hcd >> >> |# mkdir /sys/kernel/config/usb_gadget/functions/acm.one > > I dont think this is enough. It doesn't cope with multiple > usb configurations. > > Or is this just to show how we could probe functions to the framework > before even binding them to a UDC ??? This loads function without even creating a gadget. This would allow the same function to be used in several different gadgets. > Anyway, what I wanted to see was something like: > > # mkdir -p /sys/kernel/config/usb_gadget/dwc3.0/gadget0/config0 \ > /sys/kernel/config/usb_gadget/dwc3.0/gadget0/config1 > > # echo acm.2,obex.3,msc > \ > /sys/kernel/config/usb_gadget/dwc3.0/gadget0/config0/functions > > # echo ffs,sourcesink > \ > /sys/kernel/config/usb_gadget/dwc3.0/gadget0/config1/functions I think that the idea expressed here was so far to use (symbolic) links to bind functions to configurations. > Then when you echo the function name to the functions file under the > configuration, if the function isn't registered, then a try_module_get() > will tell udev to load it and increment the usage counter. Also, it will > create files and other directories for every part of the every > descriptor, but, of course, only strings will be writable, everything > else is read-only. > > This means that the following should allocate and expose a device > descriptor: > > # mkdir /sys/kernel/config/usb_gadget/dwc3.0/gadget.0/ > # ls /sys/kernel/config/usb_gadget/dwc3.0/gadget.0/ Again, so far it seems everyone on the list thought to rather link a gadget to UDC via symlinking and keep UDCs and gadgets in separate directories. > Does that make sense to you ??? It would remove the need to even > create a functions/$function.$num directory for everybody before being > able to use the function. The way you've setup configfs it means that > if I'm going to use ACM on multiple configurations or even multiple > gadgets, I will have to know how many of them I will need before hand. Not necessarily. If you are not interested in sharing functions between gadgets, all you have to do is use unique prefix for the functions, for instance: cd /sys/kernel/config/usb_gadget mkdir functions/acm.blah-0 mkdir gadgets/blah mkdir gadgets/blah/configs/config0 # or slightly different name ln -s functions/acm.blah0 ln -s functions/acm.blah0 gadgets/blah/configs/config0/function0 -- Best regards, _ _ .o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o ..o | Computer Science, Michał “mina86” Nazarewicz (o o) ooo +----<email/xmpp: mpn@xxxxxxxxxx>--------------ooO--(_)--Ooo--
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