On Tue, Oct 02, 2012 at 04:27:07PM -0600, Daniel Drake wrote: > Hi, > > For the upcoming OLPC touchscreen laptop we're trying to solve the > following problem: we want the on-screen keyboard to only activate > itself when the laptop is "folded over" into tablet mode where the > keyboard is physically obscured. > > We already have an ebook mode switch which detects this, and the > driver is upstream. Its an input device that exposes this information > via the SW_TABLET_MODE switch. > > The on-screen keyboard runs in the user environment, which means that > its not root - it can't access /dev/input/event nodes directly. X > doesn't treat switches as input devices, so this info is not available > through X. > > I'm wondering if anyone has suggestions on the best way to solve this > problem. The most attractive option I have found would be to do > something similar to the accelerometer: > http://git.kernel.org/?p=linux/hotplug/udev.git;a=blob;f=src/accelerometer/accelerometer.c > > Modify the kernel input driver to generate a uevent (in addition to > the evdev event) every time the switch state is changed, then write a > udev program to expose this info in a udev property. > > The change event would (presumably) trigger libudev's udev_monitor, > which would be used by the on-screen keyboard software (maliit) to > change its behaviour according to the property value. > > Does this sound like a sensible plan, would these udev and kernel > changes be acceptable? Or is there a better option that I'm missing? Why can't you change event device ownership to the local user? Then you can read and act upon events. Thanks. -- Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-hotplug" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
