diff options
| author | Vignesh R <vigneshr@ti.com> | 2015-02-03 22:45:34 +0300 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2015-02-03 22:50:38 +0300 |
| commit | bf223612a4cd65d5eb15d6adc8422c7d61ae75dd (patch) | |
| tree | f4c31201c77ba2e66cd78495ec3aa1efc630df53 /Documentation/devicetree/bindings/input | |
| parent | 344d635b9a41b19837ccf8083a99ea688027019c (diff) | |
| download | linux-bf223612a4cd65d5eb15d6adc8422c7d61ae75dd.tar.xz | |
Input: ti_am335x_tsc - read charge delay from DT
This patch reads charge delay from tsc DT node and writes to
REG_CHARGEDELAY register. If the charge delay is not specified in DT then
default value of 0x400(CHARGEDLY_OPENDLY) is used.
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Diffstat (limited to 'Documentation/devicetree/bindings/input')
| -rw-r--r-- | Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt b/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt index 878549ba814d..6c4fb34823d3 100644 --- a/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt +++ b/Documentation/devicetree/bindings/input/touchscreen/ti-tsc-adc.txt @@ -28,6 +28,20 @@ Required properties: ti,adc-channels: List of analog inputs available for ADC. AIN0 = 0, AIN1 = 1 and so on till AIN7 = 7. +Optional properties: +- child "tsc" + ti,charge-delay: Length of touch screen charge delay step in terms of + ADC clock cycles. Charge delay value should be large + in order to avoid false pen-up events. This value + effects the overall sampling speed, hence need to be + kept as low as possible, while avoiding false pen-up + event. Start from a lower value, say 0x400, and + increase value until false pen-up events are avoided. + The pen-up detection happens immediately after the + charge step, so this does in fact function as a + hardware knob for adjusting the amount of "settling + time". + Example: tscadc: tscadc@44e0d000 { compatible = "ti,am3359-tscadc"; @@ -36,6 +50,7 @@ Example: ti,x-plate-resistance = <200>; ti,coordiante-readouts = <5>; ti,wire-config = <0x00 0x11 0x22 0x33>; + ti,charge-delay = <0x400>; }; adc { |