Messages in this thread | | | Date | Fri, 22 Aug 2008 14:02:56 -0400 | From | Dmitry Torokhov <> | Subject | Re: [RFC][PATCH] POSKeyboard driver for exclusive keyboard access |
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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.
> 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.
> - Does serio_unregister_port() a kfree() on the port?
Eventually, after the last user drops off.
-- Dmitry
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