Documentation/devicetree/bindings/input/touchscreen/brcm,iproc-touchscreen.txt

   1 * Broadcom's IPROC Touchscreen Controller
   2
   3 Required properties:
   4 - compatible: must be "brcm,iproc-touchscreen"
   5 - reg: physical base address of the controller and length of memory mapped
   6   region.
   7 - clocks:  The clock provided by the SOC to driver the tsc
   8 - clock-name:  name for the clock
   9 - interrupts: The touchscreen controller's interrupt
  10
  11 Optional properties:
  12 - scanning_period: Time between scans. Each step is 1024 us.  Valid 1-256.
  13 - debounce_timeout: Each step is 512 us.  Valid 0-255
  14 - settling_timeout: The settling duration (in ms) is the amount of time
  15                     the tsc waits to allow the voltage to settle after
  16                     turning on the drivers in detection mode.
  17                     Valid values: 0-11
  18                     0 =  0.008 ms
  19                     1 =  0.01 ms
  20                     2 =  0.02 ms
  21                     3 =  0.04 ms
  22                     4 =  0.08 ms
  23                     5 =  0.16 ms
  24                     6 =  0.32 ms
  25                     7 =  0.64 ms
  26                     8 =  1.28 ms
  27                     9 =  2.56 ms
  28                    10 =  5.12 ms
  29                    11 = 10.24 ms
  30 - touch_timeout: The continuous number of scan periods in which touch is
  31                 not detected before the controller returns to idle state.
  32                 Valid values 0-255.
  33 - average_data: Number of data samples which are averaged before a final
  34                 data point is placed into the FIFO
  35                 Valid values 0-7
  36                 0 =   1 sample
  37                 1 =   2 samples
  38                 2 =   4 samples
  39                 3 =   8 samples
  40                 4 =  16 samples
  41                 5 =  32 samples
  42                 6 =  64 samples
  43                 7 = 128 samples
  44 - fifo_threshold: Interrupt is generated whenever the number of fifo
  45                 entries exceeds this value
  46                 Valid values 0-31
  47 - touchscreen-size-x: horizontal resolution of touchscreen (in pixels)
  48 - touchscreen-size-y: vertical resolution of touchscreen (in pixels)
  49 - touchscreen-fuzz-x: horizontal noise value of the absolute input
  50                       device (in pixels)
  51 - touchscreen-fuzz-y: vertical noise value of the absolute input
  52                       device (in pixels)
  53 - touchscreen-inverted-x: X axis is inverted (boolean)
  54 - touchscreen-inverted-y: Y axis is inverted (boolean)
  55
  56 Example:
  57
  58         touchscreen: tsc@0x180A6000 {
  59                 compatible = "brcm,iproc-touchscreen";
  60                 #address-cells = <1>;
  61                 #size-cells = <1>;
  62                 reg = <0x180A6000 0x40>;
  63                 clocks = <&adc_clk>;
  64                 clock-names = "tsc_clk";
  65                 interrupts = <GIC_SPI 164 IRQ_TYPE_LEVEL_HIGH>;
  66
  67                 scanning_period = <5>;
  68                 debounce_timeout = <40>;
  69                 settling_timeout = <7>;
  70                 touch_timeout = <10>;
  71                 average_data = <5>;
  72                 fifo_threshold = <1>;
  73                 /* Touchscreen is rotated 180 degrees. */
  74                 touchscreen-inverted-x;
  75                 touchscreen-inverted-y;
  76         };