94 lines
3 KiB
Plaintext
94 lines
3 KiB
Plaintext
Device tree bindings for TI's ADS7843, ADS7845, ADS7846, ADS7873, TSC2046
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SPI driven touch screen controllers.
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The node for this driver must be a child node of a SPI controller, hence
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all mandatory properties described in
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Documentation/devicetree/bindings/spi/spi-bus.txt
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must be specified.
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Additional required properties:
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compatible Must be one of the following, depending on the
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model:
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"ti,tsc2046"
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"ti,ads7843"
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"ti,ads7845"
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"ti,ads7846"
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"ti,ads7873"
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interrupts An interrupt node describing the IRQ line the chip's
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!PENIRQ pin is connected to.
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vcc-supply A regulator node for the supply voltage.
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Optional properties:
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ti,vref-delay-usecs vref supply delay in usecs, 0 for
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external vref (u16).
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ti,vref-mv The VREF voltage, in millivolts (u16).
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Set to 0 to use internal references
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(ADS7846).
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ti,keep-vref-on set to keep vref on for differential
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measurements as well
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ti,swap-xy swap x and y axis
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ti,settle-delay-usec Settling time of the analog signals;
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a function of Vcc and the capacitance
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on the X/Y drivers. If set to non-zero,
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two samples are taken with settle_delay
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us apart, and the second one is used.
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~150 uSec with 0.01uF caps (u16).
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ti,penirq-recheck-delay-usecs If set to non-zero, after samples are
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taken this delay is applied and penirq
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is rechecked, to help avoid false
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events. This value is affected by the
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material used to build the touch layer
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(u16).
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ti,x-plate-ohms Resistance of the X-plate,
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in Ohms (u16).
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ti,y-plate-ohms Resistance of the Y-plate,
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in Ohms (u16).
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ti,x-min Minimum value on the X axis (u16).
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ti,y-min Minimum value on the Y axis (u16).
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ti,x-max Maximum value on the X axis (u16).
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ti,y-max Minimum value on the Y axis (u16).
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ti,pressure-min Minimum reported pressure value
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(threshold) - u16.
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ti,pressure-max Maximum reported pressure value (u16).
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ti,debounce-max Max number of additional readings per
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sample (u16).
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ti,debounce-tol Tolerance used for filtering (u16).
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ti,debounce-rep Additional consecutive good readings
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required after the first two (u16).
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ti,pendown-gpio-debounce Platform specific debounce time for the
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pendown-gpio (u32).
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pendown-gpio GPIO handle describing the pin the !PENIRQ
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line is connected to.
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wakeup-source use any event on touchscreen as wakeup event.
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(Legacy property support: "linux,wakeup")
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Example for a TSC2046 chip connected to an McSPI controller of an OMAP SoC::
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spi_controller {
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tsc2046@0 {
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reg = <0>; /* CS0 */
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compatible = "ti,tsc2046";
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interrupt-parent = <&gpio1>;
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interrupts = <8 0>; /* BOOT6 / GPIO 8 */
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spi-max-frequency = <1000000>;
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pendown-gpio = <&gpio1 8 0>;
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vcc-supply = <®_vcc3>;
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ti,x-min = /bits/ 16 <0>;
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ti,x-max = /bits/ 16 <8000>;
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ti,y-min = /bits/ 16 <0>;
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ti,y-max = /bits/ 16 <4800>;
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ti,x-plate-ohms = /bits/ 16 <40>;
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ti,pressure-max = /bits/ 16 <255>;
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wakeup-source;
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};
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};
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