Fuze+: add a configurable deadzone area for touchpad buttons

To stop erroneous button presses, allow users to add a deadzone between
the button via the Settings > General > System menu > Touch Dead Zone.

The configuration was chosen this way: the touchpad has the same DPI
in both direction so the setting applies the same on both the X and Y
axis. The setting ranges from 0 to 100 and is internally multiplied by 2
giving a maximum deadzone of 2*100 = 200 around each button, which
account for 400 total (once around each button), effectively reducing
each virtual button from 1000x600 to 600x200 when using the maximum value.

Change-Id: I8683c63d2950200eb32d1dda0a00bbd92d83d5be
Reviewed-on: http://gerrit.rockbox.org/677
Reviewed-by: Benjamin Brown <foolshperson@gmail.com>
Tested: Benjamin Brown <foolshperson@gmail.com>
Reviewed-by: Amaury Pouly <amaury.pouly@gmail.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/firmware/target/arm/imx233/sansa-fuzeplus/button-target.h b/firmware/target/arm/imx233/sansa-fuzeplus/button-target.h
index ce5ffe464a..7a4396e0f2 100644
--- a/firmware/target/arm/imx233/sansa-fuzeplus/button-target.h
+++ b/firmware/target/arm/imx233/sansa-fuzeplus/button-target.h
@@ -24,6 +24,7 @@
 #include <stdbool.h>
 bool button_debug_screen(void);
 void touchpad_set_sensitivity(int level);
+void touchpad_set_deadzone(int touchpad_deadzone);
 void touchpad_enable_device(bool en);
 
 /* Main unit's buttons */