On Thu, May 24, 2018 at 07:38:41PM +0200, Ricardo Ribalda Delgado wrote: > On Thu, May 24, 2018 at 6:49 PM Rob Herring <robh@xxxxxxxxxx> wrote: > > The fundamental problem here is you need a parent device node to apply > > a DT overlay to and a USB device hotplugged has no DT device node. The > > system you are running on may not even have a DT (like a PC). If you > > have an overlay of the downstream devices, they have to be a child of > > something for the overlay to apply to. We could just create virtual > > device nodes for the purposes of applying overlays to. Another option > > would be allowing multiple DTs. Then you aren't even using overlays > > (what's the point of an overlay when a system has no real DT to begin > > with). That also would mean they are completely independent from any > > real DT or other instances (you may want to plug in multiple of the > > same device). > > In my usecase the DT is way too overkilled. The previously mentioned > echo tty > /sys/bus/serio/devices/serio0/unregister > echo hci_nokia > /sys/bus/serio/devices/serio0/new_device > > would be the most convenient way to use/experiment with serio. Note is serio is something different from serdev (whose bus type is named "serial"). > I am not taking into consideration hot pluggable devices. I am thinking > about a use case where the usb2serial is soldered in the board. For static setups like that, my USB serial device-tree patches would solve your problem if only you were using device tree. ;) But there's currently no way to register a serdev client from user space, and adding support for that is not going to be trivial. Johan -- 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
