Adding XPT2046 ( ADS7846 ) Touchscreen Support to Beaglebone Black Kernel version 4.1.0-rc5-bone3

BB-ADS7846-00A0.dts

/dts-v1/;
/plugin/;

#include <dt-bindings/board/am335x-bbw-bbb-base.h>
#include <dt-bindings/pinctrl/am33xx.h>

/ {
	compatible = "ti,beaglebone", "ti,beaglebone-black";

	/* identification */
	part-number = "BB-ADS7846";
	version = "00A0";

        /* state the resources this cape uses */
        exclusive-use =
                /* the pin header uses */
                "P9.17",        /* SPI0_CS0 */
                "P9.18",        /* SPI0_D1 */
                "P9.21",        /* SPI0_D0 */
                "P9.22",        /* SPI0_SCLK */
                "P9.23";       /* pendown */

	fragment@0 {
		target = <&am33xx_pinmux>;
		__overlay__ {
		 ads7846_pins:pinmux_spi0_pins {
				pinctrl-single,pins = <
        	0x150 0x30 /* spi0_sclk, INPUT_PULLUP | MODE0 */
        	0x154 0x10 /* spi0_d0, OUTPUT_PULLUP | MODE0 */
        	0x158 0x30 /* spi0_d1, INPUT_PULLUP | MODE0 */
        	/* For ADS7846 */
	        0x15c 0x10 /* spi0_cs0, OUTPUT_PULLUP | MODE0 */
				>;
			};
		};
};

	fragment@1 {
		target = <&spi0>;
		__overlay__ {
			#address-cells = <0x1>;
	     	        #size-cells = <0>;
			status = "okay";
			pinctrl-names = "default";
			pinctrl-0 = <&ads7846_pins>;
			ti,pindir-d0-out-d1-in = <1>;
 		    ads7846@0 {
				compatible = "ti,ads7846";
				spi-max-frequency = <100000>;   /* Higher frequency causes more jitter */
				interrupts = <17 0>;             /* pin number 17 and falling edge interrupt */
				interrupt-parent = <&gpio1>;
				pendown-gpio = <&gpio1 17 0>;        /* This corresponds to pin no 23 = GPIO1[17]*/
				reg = <0>;     /* We are using chip select 0, so we enter 0 here */
                #addr-size = <2>;
                #page-size = <32>;

                /* driver defaults */
                ti,x-min = /bits/ 16 <0xB0>;
                ti,y-min = /bits/ 16 <0x231>;
                ti,x-max = /bits/ 16 <0xF49>;
                ti,y-max = /bits/ 16 <0xF6B>;
                ti,pressure-min = /bits/ 16 <0>;
                ti,pressure-max = /bits/ 16 <0xFF>;
                ti,x-plate-ohms = /bits/ 16 <0x96>;
                ti,swap_xy = /bits/ 16 <0>;
                ti,keep_vref_on = /bits/ 16 <0>;
                ti,cs = /bits/ 16 <1>;
    		    linux,wakeup;
	        };
        };
    };
};