dtsfile

/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 */
                "P9.25",        /*pendown */
                /* the hardware it uses */
                "spi0";

        fragment@0 {
                target = <&am33xx_pinmux>;
                __overlay__ {
                 ads7846:pinmux_ads7846_pins {
                                pinctrl-single,pins = <
                                        BONE_P9_17 (PIN_OUTPUT_PULLUP | MUX_MODE0) /* gpmc_wait0.uart4_rxd_mux2 */
                                        BONE_P9_18 (PIN_OUTPUT_PULLUP | MUX_MODE0) /* gpmc_wpn.uart4_txd_mux2 */
                                        BONE_P9_21 (PIN_INPUT_PULLUP | MUX_MODE0) /* gpmc_wpn.uart4_txd_mux2 */
                                        BONE_P9_22 (PIN_OUTPUT_PULLUP | MUX_MODE0) /* gpmc_wpn.uart4_txd_mux2 */
                                        BONE_P9_25 (PIN_INPUT_PULLDOWN | MUX_MODE0) /* gpmc_wpn.uart4_txd_mux2 */
                                >;
                                linux,phandle = <0x1>;
                                phandle = <0x1>;
                        };
                };
};

        fragment@1 {
                target = <&spi0>;
                __overlay__ {
                        #address-cells = <0x1>;
                        #size-cells = <0>;
                        status = "okay";
                        pinctrl-names = "default";
                        pinctrl-0 = <&ads7846>;
                 ads7846@0 {
                                compatible = "linux,spidev";
                                spi-max-frequency = <2000000>;
                                interrupts = <255 2>; /* high-to-low edge triggered */
                                interrupt-parent = <&gpio3>;
                                pendown-gpio = <&gpio3 255 0>;
                                reg = <0>;

                                /* driver defaults */
                                ti,x-min = /bits/ 16 <0>;
                                ti,y-min = /bits/ 16 <0>;
                                ti,x-max = /bits/ 16 <0x0FFF>;
                                ti,y-max = /bits/ 16 <0x0FFF>;
                                ti,pressure-min = /bits/ 16 <0>;
                                ti,pressure-max = /bits/ 16 <0xFFFF>;
                                ti,x-plate-ohms = /bits/ 16 <400>;
                        };
                };
        };
};