The patch titled keyboard notifier documentation has been added to the -mm tree. Its filename is keyboard-notifier-documentation.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: keyboard notifier documentation From: Samuel Thibault <samuel.thibault@xxxxxxxxxxxx> Document the keyboard notifier. Signed-off-by: Samuel Thibault <samuel.thibault@xxxxxxxxxxxx> Cc: Dmitry Torokhov <dtor@xxxxxxx> Cc: Rob Landley <rob@xxxxxxxxxxx> Cc: "Randy.Dunlap" <rdunlap@xxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- Documentation/input/notifier.txt | 52 +++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) diff -puN /dev/null Documentation/input/notifier.txt --- /dev/null +++ a/Documentation/input/notifier.txt @@ -0,0 +1,52 @@ +Keyboard notifier + +One can use register_keyboard_notifier to get called back on keyboard +events (see kbd_keycode() function for details). The passed structure is +keyboard_notifier_param: + +- 'vc' always provide the VC for which the keyboard event applies; +- 'down' is 1 for a key press event, 0 for a key release; +- 'shift' is the current modifier state, mask bit indexes are KG_*; +- 'value' depends on the type of event. + +- KBD_KEYCODE events are always sent before other events, value is the keycode. +- KBD_UNBOUND_KEYCODE events are sent if the keycode is not bound to a keysym. + value is the keycode. +- KBD_UNICODE events are sent if the keycode -> keysym translation produced a + unicode character. value is the unicode value. +- KBD_KEYSYM events are sent if the keycode -> keysym translation produced a + non-unicode character. value is the keysym. +- KBD_POST_KEYSYM events are sent after the treatment of non-unicode keysyms. + That permits one to inspect the resulting LEDs for instance. + +For each kind of event but the last, the callback may return NOTIFY_STOP in +order to "eat" the event: the notify loop is stopped and the keyboard event is +dropped. + +In a rough C snippet, we have: + +kbd_keycode(keycode) { + ... + params.value = keycode; + if (notifier_call_chain(KBD_KEYCODE,¶ms) == NOTIFY_STOP) + || !bound) { + notifier_call_chain(KBD_UNBOUND_KEYCODE,¶ms); + return; + } + + if (unicode) { + param.value = unicode; + if (notifier_call_chain(KBD_UNICODE,¶ms) == NOTIFY_STOP) + return; + emit unicode; + return; + } + + params.value = keysym; + if (notifier_call_chain(KBD_KEYSYM,¶ms) == NOTIFY_STOP) + return; + apply keysym; + notifier_call_chain(KBD_POST_KEYSYM,¶ms); +} + +NOTE: This notifier is usually called from interrupt context. _ Patches currently in -mm which might be from samuel.thibault@xxxxxxxxxxxx are keyboard-notifier-documentation.patch - To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html