Kernel-4.18.0-80.el8_brcm,iproc-touchscreen

• Broadcom’s IPROC Touchscreen Controller

Required properties:

• compatible: must be “brcm,iproc-touchscreen”
• ts_syscon: handler of syscon node defining physical base
  address of the controller and length of memory mapped region.
  If this property is selected please make sure MFD_SYSCON config
  is enabled in the defconfig file.
• clocks: The clock provided by the SOC to driver the tsc
• clock-names: name for the clock
• interrupts: The touchscreen controller’s interrupt
• address-cells: Specify the number of u32 entries needed in child nodes.
  Should set to 1.
• size-cells: Specify number of u32 entries needed to specify child nodes size
  in reg property. Should set to 1.

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: An example of touchscreen node

ts_adc_syscon: ts_adc_syscon@180a6000 {
    compatible = "brcm,iproc-ts-adc-syscon","syscon";
    reg = <0x180a6000 0xc30>;
};

touchscreen: touchscreen@180a6000 {
    compatible = "brcm,iproc-touchscreen";
    #address-cells = <1>;
    #size-cells = <1>;
    ts_syscon = <&ts_adc_syscon>;
    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;
};