raspi3-tutorial/08_power/power.c

/*
 * Copyright (C) 2018 bzt (bztsrc@github)
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use, copy,
 * modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 *
 */

#include "gpio.h"
#include "mbox.h"
#include "delays.h"

#define PM_RSTC         ((volatile unsigned int*)(MMIO_BASE+0x0010001c))
#define PM_RSTS         ((volatile unsigned int*)(MMIO_BASE+0x00100020))
#define PM_WDOG         ((volatile unsigned int*)(MMIO_BASE+0x00100024))
#define PM_WDOG_MAGIC   0x5a000000
#define PM_RSTC_FULLRST 0x00000020

/**
 * Shutdown the board
 */
void power_off()
{
    unsigned long r;

    // power off devices one by one
    for(r=0;r<16;r++) {
        mbox[0]=8*4;
        mbox[1]=MBOX_REQUEST;
        mbox[2]=MBOX_TAG_SETPOWER; // set power state
        mbox[3]=8;
        mbox[4]=8;
        mbox[5]=(unsigned int)r;   // device id
        mbox[6]=0;                 // bit 0: off, bit 1: no wait
        mbox[7]=MBOX_TAG_LAST;
        mbox_call(MBOX_CH_PROP);
    }

    // power off gpio pins (but not VCC pins)
    *GPFSEL0 = 0; *GPFSEL1 = 0; *GPFSEL2 = 0; *GPFSEL3 = 0; *GPFSEL4 = 0; *GPFSEL5 = 0;
    *GPPUD = 0;
    wait_cycles(150);
    *GPPUDCLK0 = 0xffffffff; *GPPUDCLK1 = 0xffffffff;
    wait_cycles(150);
    *GPPUDCLK0 = 0; *GPPUDCLK1 = 0;        // flush GPIO setup

    // power off the SoC (GPU + CPU)
    r = *PM_RSTS; r &= ~0xfffffaaa;
    r |= 0x555;    // partition 63 used to indicate halt
    *PM_RSTS = PM_WDOG_MAGIC | r;
    *PM_WDOG = PM_WDOG_MAGIC | 10;
    *PM_RSTC = PM_WDOG_MAGIC | PM_RSTC_FULLRST;
}

/**
 * Reboot
 */
void reset()
{
    unsigned int r;
    // trigger a restart by instructing the GPU to boot from partition 0
    r = *PM_RSTS; r &= ~0xfffffaaa;
    *PM_RSTS = PM_WDOG_MAGIC | r;   // boot from partition 0
    *PM_WDOG = PM_WDOG_MAGIC | 10;
    *PM_RSTC = PM_WDOG_MAGIC | PM_RSTC_FULLRST;
}