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buzz.pru0c

/*
 * Copyright (C) 2018 Jason Kridner <jdk@ti.com>, Texas Instruments Incorporated
 *
 * Source Modified by Zubeen Tolani < ZeekHuge - zeekhuge@gmail.com >
 * Based on the examples distributed by TI
 *
 * Copyright (C) 2015 Texas Instruments Incorporated - http://www.ti.com/
 *
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *      * Redistributions of source code must retain the above copyright
 *        notice, this list of conditions and the following disclaimer.
 *
 *      * Redistributions in binary form must reproduce the above copyright
 *        notice, this list of conditions and the following disclaimer in the
 *        documentation and/or other materials provided with the
 *        distribution.
 *
 *      * Neither the name of Texas Instruments Incorporated nor the names of
 *        its contributors may be used to endorse or promote products derived
 *        from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <stdint.h>
#include <pru_cfg.h>
#include <pru_ctrl.h>
#include <stddef.h>
#include <rsc_types.h>

#define INS_PER_US 200           // 5ns per instruction
#define INS_PER_DELAY_LOOP 2     // two instructions per delay loop
#define DELAY_CYCLES    1250*(INS_PER_US / INS_PER_DELAY_LOOP)  // About 2*400Hz

volatile register unsigned int __R30;
volatile register unsigned int __R31;
#define PRU0_GPIO (1<<3)

struct my_resource_table {
        struct resource_table base;

        uint32_t offset[1]; /* Should match 'num' in actual definition */
};

#pragma DATA_SECTION(pru_remoteproc_ResourceTable, ".resource_table")
#pragma RETAIN(pru_remoteproc_ResourceTable)
struct my_resource_table pru_remoteproc_ResourceTable = {
        1,      /* we're the first version that implements this */
        0,      /* number of entries in the table */
        0, 0,   /* reserved, must be zero */
        0,      /* offset[0] */
};

#pragma DATA_SECTION(init_pins, ".init_pins")
#pragma RETAIN(init_pins)
const char init_pins[] =  
	"/sys/devices/platform/ocp/ocp:P2_30_pinmux/state\0pruout\0" \
	"\0\0";

void main(void) {
        int i;

        /* Toggle GPIO at 400Hz for 1s */
        for(i = 0; i < 400; i++) {
                __R30 |= PRU0_GPIO;
                __delay_cycles(DELAY_CYCLES);
                __R30 ^= PRU0_GPIO;
                __delay_cycles(DELAY_CYCLES);
        }

        __halt();
}