From mboxrd@z Thu Jan 1 00:00:00 1970 From: Samuel Thibault Subject: [PATCH] Let keyboard notifiers modify key codes Date: Wed, 7 Jan 2009 01:58:13 +0100 Message-ID: <20090107005813.GA4987@const.famille.thibault.fr> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org Cc: akpm@linux-foundation.org, dmitry.torokhov@gmail.com, linux-input@vger.kernel.org List-Id: linux-input@vger.kernel.org Make kbd_keycode() read param.value after calling the keyboard notification chain, to let the callee change the translation on the fly. This for instance permits to remap the physical positions of the keys independently of the configured keymap, for e.g. single-handed people. Signed-off-by: Samuel Thibault --- linux/drivers/char/keyboard.c.orig 2009-01-07 00:48:46.000000000 +0100 +++ linux/drivers/char/keyboard.c 2009-01-07 01:02:05.000000000 +0100 @@ -1248,6 +1248,7 @@ kbd_keycode kbd->slockstate = 0; return; } + keycode = param.value; if (keycode >= NR_KEYS) if (keycode >= KEY_BRL_DOT1 && keycode <= KEY_BRL_DOT8) @@ -1263,6 +1264,7 @@ kbd_keycode param.value = keysym; if (atomic_notifier_call_chain(&keyboard_notifier_list, KBD_UNICODE, ¶m) == NOTIFY_STOP) return; + keysym = param.value; if (down && !raw_mode) to_utf8(vc, keysym); return; @@ -1282,6 +1284,7 @@ kbd_keycode if (atomic_notifier_call_chain(&keyboard_notifier_list, KBD_KEYSYM, ¶m) == NOTIFY_STOP) return; + keysym = param.value; if (raw_mode && type != KT_SPEC && type != KT_SHIFT) return; --- linux/Documentation/input/notifier.txt.orig 2008-04-17 12:14:30.000000000 +0200 +++ linux/Documentation/input/notifier.txt 2009-01-07 01:04:16.000000000 +0100 @@ -21,7 +21,8 @@ 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. +dropped. The callee can also modify param.value so as to change the key +translation. In a rough C snippet, we have: @@ -33,18 +34,26 @@ notifier_call_chain(KBD_UNBOUND_KEYCODE,¶ms); return; } + keycode = param.value; + + ... if (unicode) { param.value = unicode; if (notifier_call_chain(KBD_UNICODE,¶ms) == NOTIFY_STOP) return; + keysym = param.value; emit unicode; return; } + ... + params.value = keysym; if (notifier_call_chain(KBD_KEYSYM,¶ms) == NOTIFY_STOP) return; + keysym = params.value; + apply keysym; notifier_call_chain(KBD_POST_KEYSYM,¶ms); }