PRU UART overlay

gistfile1.txt

/* Device Tree Overlay for enabling the pins that are used in Chapter 13
* This overlay is based on the BB-PRU-01 overlay
* Written by Derek Molloy for the book "Exploring BeagleBone: Tools and
* Techniques for Building with Embedded Linux" by John Wiley & Sons, 2014
* ISBN 9781118935125. Please see the file README.md in the repository root
* directory for copyright and GNU GPLv3 license information.
*/
/dts-v1/;
/plugin/;

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

   part-number = "B4-PRU-Example";
   version = "00A0";

   /* This overlay uses the following resources */
   exclusive-use =
				"P9.17", "P9.18", "pru1";


   fragment@0 {
      target = <&am33xx_pinmux>;
      __overlay__ {

         pru_pru_pins: pinmux_pru_pru_pins {   // The PRU pin modes
            pinctrl-single,pins = <

							0x15c 0x14		// pr1_uart0 tx, output fast slew pull up mux 4
							0x158 0x34		// pr1_uar0 rx, input fast slew pull up mux 4

            >;
         };
      };
   };

   fragment@1 {         // Enable the PRUSS
      target = <&pruss>;
      __overlay__ {
         status = "okay";
         pinctrl-names = "default";
         pinctrl-0 = <&pru_pru_pins>;
      };
   };


};