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authorDaniel Mack <zonque@gmail.com>2013-06-27 23:42:17 -0700
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2013-07-02 20:40:50 -0700
commita608026eacaee59cf0f1fa5caad60320f5b4a373 (patch)
tree8eb83f350a6a9855e24ce7b0d2d90e8b8a0ee612 /Documentation/devicetree/bindings/input
parent57691a1e27a7d1995775b7e25e2ec0d7a415edc0 (diff)
Input: ads7846 - add device tree bindings
Signed-off-by: Daniel Mack <zonque@gmail.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
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+Device tree bindings for TI's ADS7843, ADS7845, ADS7846, ADS7873, TSC2046
+SPI driven touch screen controllers.
+
+The node for this driver must be a child node of a SPI controller, hence
+all mandatory properties described in
+
+ Documentation/devicetree/bindings/spi/spi-bus.txt
+
+must be specified.
+
+Additional required properties:
+
+ compatible Must be one of the following, depending on the
+ model:
+ "ti,tsc2046"
+ "ti,ads7843"
+ "ti,ads7845"
+ "ti,ads7846"
+ "ti,ads7873"
+
+ interrupt-parent
+ interrupts An interrupt node describing the IRQ line the chip's
+ !PENIRQ pin is connected to.
+ vcc-supply A regulator node for the supply voltage.
+
+
+Optional properties:
+
+ ti,vref-delay-usecs vref supply delay in usecs, 0 for
+ external vref (u16).
+ ti,vref-mv The VREF voltage, in millivolts (u16).
+ ti,keep-vref-on set to keep vref on for differential
+ measurements as well
+ ti,swap-xy swap x and y axis
+ ti,settle-delay-usec Settling time of the analog signals;
+ a function of Vcc and the capacitance
+ on the X/Y drivers. If set to non-zero,
+ two samples are taken with settle_delay
+ us apart, and the second one is used.
+ ~150 uSec with 0.01uF caps (u16).
+ ti,penirq-recheck-delay-usecs If set to non-zero, after samples are
+ taken this delay is applied and penirq
+ is rechecked, to help avoid false
+ events. This value is affected by the
+ material used to build the touch layer
+ (u16).
+ ti,x-plate-ohms Resistance of the X-plate,
+ in Ohms (u16).
+ ti,y-plate-ohms Resistance of the Y-plate,
+ in Ohms (u16).
+ ti,x-min Minimum value on the X axis (u16).
+ ti,y-min Minimum value on the Y axis (u16).
+ ti,x-max Maximum value on the X axis (u16).
+ ti,y-max Minimum value on the Y axis (u16).
+ ti,pressure-min Minimum reported pressure value
+ (threshold) - u16.
+ ti,pressure-max Maximum reported pressure value (u16).
+ ti,debounce-max Max number of additional readings per
+ sample (u16).
+ ti,debounce-tol Tolerance used for filtering (u16).
+ ti,debounce-rep Additional consecutive good readings
+ required after the first two (u16).
+ ti,pendown-gpio-debounce Platform specific debounce time for the
+ pendown-gpio (u32).
+ pendown-gpio GPIO handle describing the pin the !PENIRQ
+ line is connected to.
+ linux,wakeup use any event on touchscreen as wakeup event.
+
+
+Example for a TSC2046 chip connected to an McSPI controller of an OMAP SoC::
+
+ spi_controller {
+ tsc2046@0 {
+ reg = <0>; /* CS0 */
+ compatible = "ti,tsc2046";
+ interrupt-parent = <&gpio1>;
+ interrupts = <8 0>; /* BOOT6 / GPIO 8 */
+ spi-max-frequency = <1000000>;
+ pendown-gpio = <&gpio1 8 0>;
+ vcc-supply = <&reg_vcc3>;
+
+ ti,x-min = /bits/ 16 <0>;
+ ti,x-max = /bits/ 16 <8000>;
+ ti,y-min = /bits/ 16 <0>;
+ ti,y-max = /bits/ 16 <4800>;
+ ti,x-plate-ohms = /bits/ 16 <40>;
+ ti,pressure-max = /bits/ 16 <255>;
+
+ linux,wakeup;
+ };
+ };

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