Input: tegra-kbc - add support for rows/columns configuration from dt

The NVIDIA's Tegra KBC has maximum 24 pins to make matrix keypad.
Any pin can be configured as row or column. The maximum column pin
can be 8 and maximum row pin can be 16.

Remove the assumption that all first 16 pins will be used as row
and remaining as columns and Add the property for configuring pins
to either row or column from DT. Update the devicetree binding
document accordingly.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 22 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/input/nvidia,tegra20-kbc.txt b/Documentation/devicetree/bindings/input/nvidia,tegra20-kbc.txt
index 72683be6de35..2995fae7ee47 100644
--- a/Documentation/devicetree/bindings/input/nvidia,tegra20-kbc.txt
+++ b/Documentation/devicetree/bindings/input/nvidia,tegra20-kbc.txt
@@ -1,7 +1,18 @@
 * Tegra keyboard controller
+The key controller has maximum 24 pins to make matrix keypad. Any pin
+can be configured as row or column. The maximum column pin can be 8
+and maximum row pins can be 16 for Tegra20/Tegra30.
 
 Required properties:
 - compatible: "nvidia,tegra20-kbc"
+- reg: Register base address of KBC.
+- interrupts: Interrupt number for the KBC.
+- nvidia,kbc-row-pins: The KBC pins which are configured as row. This is an
+  array of pin numbers which is used as rows.
+- nvidia,kbc-col-pins: The KBC pins which are configured as column. This is an
+  array of pin numbers which is used as column.
+- linux,keymap: The keymap for keys as described in the binding document
+  devicetree/bindings/input/matrix-keymap.txt.
 
 Optional properties, in addition to those specified by the shared
 matrix-keyboard bindings:
@@ -19,5 +30,16 @@ Example:
 keyboard: keyboard {
         compatible = "nvidia,tegra20-kbc";
         reg = <0x7000e200 0x100>;
+        interrupts = <0 85 0x04>;
         nvidia,ghost-filter;
+        nvidia,debounce-delay-ms = <640>;
+        nvidia,kbc-row-pins = <0 1 2>;    /* pin 0, 1, 2 as rows */
+        nvidia,kbc-col-pins = <11 12 13>; /* pin 11, 12, 13 as columns */
+        linux,keymap = <0x00000074
+                        0x00010067
+                        0x00020066
+                        0x01010068
+                        0x02000069
+                        0x02010070
+                        0x02020071>;
 };