Input: ads7846 - add device tree bindings

Signed-off-by: Daniel Mack <zonque@gmail.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 91 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/input/ads7846.txt b/Documentation/devicetree/bindings/input/ads7846.txt
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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;
+                };
+        };