Hello Dmitry, Dmitry Torokhov wrote: > Hi Niels, > > On Fri, Aug 22, 2008 at 06:17:28PM +0200, Niels de Vos wrote: >> This new driver makes it possible for middleware like JavaPOS to use >> a POSKeyboard (connected to PS/2) with exclusive access. This is >> required by the UnifiedPOS Specification which is available from >> http://www.nrf-arts.org/UnifiedPOS. Any middleware using this driver >> should implement the full exception-handling in user-space. Therefor >> it is possible to use specific POS-extensions of POSKeyboards, without >> abusing other keyboard-drivers. >> >> Opening /dev/poskeyboard will route all scancodes to this device. The >> scancodes will not be processes by the input-subsystem anymore. Reading >> /dev/poskeyboard results in receiving the scancodes as raw data for >> further processing by the reader. Sending commands to the hardware can >> be done by writing to /dev/poskeyboard. >> >> If the driver is loaded and /dev/poskeyboard is not opened, all >> scancodes are given to the input-subsystem. This allows 'normal' use of >> the keyboard. >> >> Making the driver active involves some commands like the following: >> echo -n serio1 > /sys/bus/serio/drivers/atkbd/unbind >> echo -n serio1 > /sys/bus/serio/drivers/poskbd/bind >> > > It seems you have just reimplemented serio_raw driver, therefore NAK. > Right now serio_raw is limited to untranslated ports but adding > SERIO_I8042XL signature should be easy. Okay, thanks for pointing this out, I'll look into using serio_raw instead. If a patch is needed I'll send you one. >> Open questions: >> - How to achieve the same with USB-HID complaint keyboards? > > Thsi is probably is the candidate for legitimate use of EVIOCGRAB. > Just grab device for exclusive access and do your processing, probably > looking at MSC_SCAN (or KEY_*, depends on how hardware-sepcific this > thing is). This approach shoudl work equally well for HID, PS/2, > serial or any other kind of keyboard/input device actually. You can > also re-inject the keystrokes you are not interested in back into > input core via uinput. Great. I already saw input_dev->grab but never really understood what it would do or how it could be used. Tried it with a small test and should be sufficient for the UnifiedPOS requirements. >> - Does serio_unregister_port() a kfree() on the port? > > Eventually, after the last user drops off. Okay, so the driver allocates it, but never needs to do a kfree() on it, because the serio-layer takes care of it. Thanks for the infos, Niels
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