touch devices: Disable touch on softlock.

Target that have a touchpad/touchscreen should disable it while
being locked (In order to avoid LCD to drain battery power due to
"key locked" constant reporting messages. If they a have a keylock
button this was already handled at driver level. If not (e.g. fuze+),
they will have to implement a switch at driver level that action.c
can operate on softlock.
This patch does the following for any target having a touchpad
or a touchscreen and no HAS_BUTTON_HOLD (ie any softlock target)
1) it implements the code to call button_enable_touch(bool en) in
action.c.
2) button_enable_touch is implemented in button.c and call
either touchpad_enable or touchscreen_enable
3) those two function are implemented respectively in touchscreen.c
and a new touchpad.c file. They provide a generic way to silents touch's
device and call a function at driver level where target specific code
can be implemented if possible/needed (for power saving for instance).
Those function name are touchpad_enable_device and touchscreen_enable_device
4) we implement an empty function at driver level of targets that need it
to have them still being able to compiled.

Change-Id: I9ead78a25bd33466a8533f5b9f259b395cb5ce49
Reviewed-on: http://gerrit.rockbox.org/569
Reviewed-by: Thomas Martitz <kugel@rockbox.org>
Reviewed-by: Amaury Pouly <amaury.pouly@gmail.com>

1 files changed, 43 insertions, 0 deletions

diff --git a/firmware/drivers/touchpad.c b/firmware/drivers/touchpad.c
new file mode 100644
index 0000000000..1d78ee1c3e
--- /dev/null
+++ b/firmware/drivers/touchpad.c
@@ -0,0 +1,43 @@
+/***************************************************************************
+ * __________ __ ___.
+ * Open \______ \ ____ ____ | | _\_ |__ _______ ___
+ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
+ * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
+ * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
+ * \/ \/ \/ \/ \/
+ * $Id$
+ *
+ * Copyright (C) 2013 by Jean-Louis Biasini
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+#include <stdbool.h>
+#include "button.h"
+#include "touchpad.h"
+#include "button-target.h"
+
+static bool touch_enabled = true;
+
+void touchpad_enable(bool en)
+{
+    if(en != touch_enabled)
+    {
+        touch_enabled = en;
+        touchpad_enable_device(en);
+    }
+}
+
+int touchpad_filter(int button)
+{
+    if(!touch_enabled)
+        button &= ~BUTTON_TOUCHPAD;
+    return button;
+}