linux/linux-5.4.31/Documentation/devicetree/bindings/input/touchscreen/brcm,iproc-touchscreen.txt

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* 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;
};