Input: add Broadcom iProc touchscreen driver

Add initial version of the Broadcom touchscreen driver.

Reviewed-by: Ray Jui <rjui@broadcom.com>
Reviewed-by: Scott Branden <sbranden@broadcom.com>
Tested-by: Scott Branden <sbranden@broadcom.com>
Signed-off-by: Jonathan Richardson <jonathar@broadcom.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 76 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/input/touchscreen/brcm,iproc-touchscreen.txt b/Documentation/devicetree/bindings/input/touchscreen/brcm,iproc-touchscreen.txt
new file mode 100644
index 000000000000..34e3382a0659
--- /dev/null
+++ b/Documentation/devicetree/bindings/input/touchscreen/brcm,iproc-touchscreen.txt
@@ -0,0 +1,76 @@
+* Broadcom's IPROC Touchscreen Controller
+
+Required properties:
+- compatible: must be "brcm,iproc-touchscreen"
+- reg: physical base address of the controller and length of memory mapped
+  region.
+- clocks:  The clock provided by the SOC to driver the tsc
+- clock-name:  name for the clock
+- interrupts: The touchscreen controller's interrupt
+
+Optional properties:
+- scanning_period: Time between scans. Each step is 1024 us.  Valid 1-256.
+- debounce_timeout: Each step is 512 us.  Valid 0-255
+- settling_timeout: The settling duration (in ms) is the amount of time
+                    the tsc waits to allow the voltage to settle after
+                    turning on the drivers in detection mode.
+                    Valid values: 0-11
+                    0 =  0.008 ms
+                    1 =  0.01 ms
+                    2 =  0.02 ms
+                    3 =  0.04 ms
+                    4 =  0.08 ms
+                    5 =  0.16 ms
+                    6 =  0.32 ms
+                    7 =  0.64 ms
+                    8 =  1.28 ms
+                    9 =  2.56 ms
+                   10 =  5.12 ms
+                   11 = 10.24 ms
+- touch_timeout: The continuous number of scan periods in which touch is
+                not detected before the controller returns to idle state.
+                Valid values 0-255.
+- average_data: Number of data samples which are averaged before a final
+                data point is placed into the FIFO
+                Valid values 0-7
+                0 =   1 sample
+                1 =   2 samples
+                2 =   4 samples
+                3 =   8 samples
+                4 =  16 samples
+                5 =  32 samples
+                6 =  64 samples
+                7 = 128 samples
+- fifo_threshold: Interrupt is generated whenever the number of fifo
+                entries exceeds this value
+                Valid values 0-31
+- touchscreen-size-x: horizontal resolution of touchscreen (in pixels)
+- touchscreen-size-y: vertical resolution of touchscreen (in pixels)
+- touchscreen-fuzz-x: horizontal noise value of the absolute input
+                      device (in pixels)
+- touchscreen-fuzz-y: vertical noise value of the absolute input
+                      device (in pixels)
+- touchscreen-inverted-x: X axis is inverted (boolean)
+- touchscreen-inverted-y: Y axis is inverted (boolean)
+
+Example:
+
+        touchscreen: tsc@0x180A6000 {
+                compatible = "brcm,iproc-touchscreen";
+                #address-cells = <1>;
+                #size-cells = <1>;
+                reg = <0x180A6000 0x40>;
+                clocks = <&adc_clk>;
+                clock-names = "tsc_clk";
+                interrupts = <GIC_SPI 164 IRQ_TYPE_LEVEL_HIGH>;
+
+                scanning_period = <5>;
+                debounce_timeout = <40>;
+                settling_timeout = <7>;
+                touch_timeout = <10>;
+                average_data = <5>;
+                fifo_threshold = <1>;
+                /* Touchscreen is rotated 180 degrees. */
+                touchscreen-inverted-x;
+                touchscreen-inverted-y;
+        };