Input: sun4i-ts - allow controlling filter and sensitivity via DT

This commit introduces two new optional device-tree properties:
"tp-sensitive-adjust": adjust sensitivity of pen down detection
"filter-type": select median and averaging filter

The previous fixed defaults, didn't work well for the Olimex
A13-LCD10TS (I have).

Signed-off-by: Jens Thiele <karme@karme.de>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 17 insertions, 2 deletions

diff --git a/Documentation/devicetree/bindings/input/touchscreen/sun4i.txt b/Documentation/devicetree/bindings/input/touchscreen/sun4i.txt
index d59d25281e9f..89abecd938cb 100644
--- a/Documentation/devicetree/bindings/input/touchscreen/sun4i.txt
+++ b/Documentation/devicetree/bindings/input/touchscreen/sun4i.txt
@@ -9,8 +9,20 @@ Required properties:
  - #thermal-sensor-cells: shall be 0
 
 Optional properties:
- - allwinner,ts-attached: boolean indicating that an actual touchscreen is
-                          attached to the controller
+ - allwinner,ts-attached         : boolean indicating that an actual touchscreen
+                                   is attached to the controller
+ - allwinner,tp-sensitive-adjust : integer (4 bits)
+                                   adjust sensitivity of pen down detection
+                                   between 0 (least sensitive) and 15
+                                   (defaults to 15)
+ - allwinner,filter-type         : integer (2 bits)
+                                   select median and averaging filter
+                                   samples used for median / averaging filter
+                                   0: 4/2
+                                   1: 5/3
+                                   2: 8/4
+                                   3: 16/8
+                                   (defaults to 1)
 
 Example:
 
@@ -20,4 +32,7 @@ Example:
                 interrupts = <29>;
                 allwinner,ts-attached;
                 #thermal-sensor-cells = <0>;
+                /* sensitive/noisy touch panel */
+                allwinner,tp-sensitive-adjust = <0>;
+                allwinner,filter-type = <3>;
         };