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, 16 insertions, 0 deletions

diff --git a/firmware/drivers/touchscreen.c b/firmware/drivers/touchscreen.c
index 823c2e7..8ce2400 100644
--- a/firmware/drivers/touchscreen.c
+++ b/firmware/drivers/touchscreen.c
@@ -31,6 +31,7 @@
 #define BUTTON_MARGIN_X (int)(LCD_WIDTH * 0.03)
 #define BUTTON_MARGIN_Y (int)(LCD_HEIGHT * 0.03)
 
+static bool touch_enabled = true;
 static enum touchscreen_mode current_mode = TOUCHSCREEN_POINT;
 static const int touchscreen_buttons[3][3] =
 {
@@ -121,6 +122,8 @@ static void map_pixels(int *x, int *y)
 /* TODO: add jitter (and others) filter */
 int touchscreen_to_pixels(int x, int y, int *data)
 {
+    if(!touch_enabled)
+        return 0;
     x &= 0xFFFF;
     y &= 0xFFFF;
 
@@ -169,6 +172,19 @@ enum touchscreen_mode touchscreen_get_mode(void)
     return current_mode;
 }
 
+void touchscreen_enable(bool en)
+{
+    if(en != touch_enabled)
+    {
+        touch_enabled = en;
+        touchscreen_enable_device(en);
+    }
+}
+
+bool touchscreen_is_enabled(void)
+{
+    return touch_enabled;
+}
 
 #if ((CONFIG_PLATFORM & PLATFORM_ANDROID) == 0)
 /* android has an API for this */