px4io.c

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/****************************************************************************
 *
 *   Copyright (c) 2012-2017 PX4 Development Team. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. Neither the name PX4 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
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 *
 ****************************************************************************/

/**
 * @file px4io.c
 * Top-level logic for the PX4IO module.
 *
 * @author Lorenz Meier <lorenz@px4.io>
 */

#include <px4_platform_common/px4_config.h>
#include "platform/cxxinitialize.h"

#include <stdio.h>  // required for task_create
#include <stdbool.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <poll.h>
#include <signal.h>
#include <crc32.h>
#include <syslog.h>

#include <drivers/drv_pwm_output.h>
#include <drivers/drv_hrt.h>

#include <perf/perf_counter.h>
#include <output_limit/output_limit.h>

#include <stm32_uart.h>

#define DEBUG
#include "px4io.h"

__EXPORT int user_start(int argc, char *argv[]);

struct sys_state_s  system_state;

static struct hrt_call serial_dma_call;

output_limit_t pwm_limit;

float dt;

/*
 * a set of debug buffers to allow us to send debug information from ISRs
 */

static volatile uint32_t msg_counter;
static volatile uint32_t last_msg_counter;
static volatile uint8_t msg_next_out, msg_next_in;

/*
 * WARNING: too large buffers here consume the memory required
 * for mixer handling. Do not allocate more than 80 bytes for
 * output.
 */
#define NUM_MSG 1
static char msg[NUM_MSG][CONFIG_USART1_TXBUFSIZE];

static void heartbeat_blink(void);
static void ring_blink(void);
static void update_mem_usage(void);

void atomic_modify_or(volatile uint16_t *target, uint16_t modification)
{
    if ((*target | modification) != *target) {
        PX4_CRITICAL_SECTION(*target |= modification);
    }
}

void atomic_modify_clear(volatile uint16_t *target, uint16_t modification)
{
    if ((*target & ~modification) != *target) {
        PX4_CRITICAL_SECTION(*target &= ~modification);
    }
}

void atomic_modify_and(volatile uint16_t *target, uint16_t modification)
{
    if ((*target & modification) != *target) {
        PX4_CRITICAL_SECTION(*target &= modification);
    }
}

/*
 * add a debug message to be printed on the console
 */
void
isr_debug(uint8_t level, const char *fmt, ...)
{
    if (level > r_page_setup[PX4IO_P_SETUP_SET_DEBUG]) {
        return;
    }

    va_list ap;
    va_start(ap, fmt);
    vsnprintf(msg[msg_next_in], sizeof(msg[0]), fmt, ap);
    va_end(ap);
    msg_next_in = (msg_next_in + 1) % NUM_MSG;
    msg_counter++;
}

/*
 * show all pending debug messages
 */
static void
show_debug_messages(void)
{
    if (msg_counter != last_msg_counter) {
        uint32_t n = msg_counter - last_msg_counter;

        if (n > NUM_MSG) { n = NUM_MSG; }

        last_msg_counter = msg_counter;

        while (n--) {
            debug("%s", msg[msg_next_out]);
            msg_next_out = (msg_next_out + 1) % NUM_MSG;
        }
    }
}

/*
 * Get the memory usage at 2 Hz while not armed
 */
static void
update_mem_usage(void)
{
    if (/* IO armed */ (r_status_flags & PX4IO_P_STATUS_FLAGS_SAFETY_OFF)
               /* and FMU is armed */ && (r_setup_arming & PX4IO_P_SETUP_ARMING_FMU_ARMED)) {
        return;
    }

    static uint64_t last_mem_time = 0;
    uint64_t now = hrt_absolute_time();

    if (now - last_mem_time > (500 * 1000)) {
        struct mallinfo minfo = mallinfo();
        r_page_status[PX4IO_P_STATUS_FREEMEM] = minfo.fordblks;
        last_mem_time = now;
    }
}

static void
heartbeat_blink(void)
{
    static bool heartbeat = false;
    LED_BLUE(heartbeat = !heartbeat);
}

static void
ring_blink(void)
{
#ifdef GPIO_LED4

    if (/* IO armed */ (r_status_flags & PX4IO_P_STATUS_FLAGS_SAFETY_OFF)
               /* and FMU is armed */ && (r_setup_arming & PX4IO_P_SETUP_ARMING_FMU_ARMED)) {
        LED_RING(1);
        return;
    }

    // XXX this led code does have
    // intentionally a few magic numbers.
    const unsigned max_brightness = 118;

    static unsigned counter = 0;
    static unsigned brightness = max_brightness;
    static unsigned brightness_counter = 0;
    static unsigned on_counter = 0;

    if (brightness_counter < max_brightness) {

        bool on = ((on_counter * 100) / brightness_counter + 1) <= ((brightness * 100) / max_brightness + 1);

        // XXX once led is PWM driven,
        // remove the ! in the line below
        // to return to the proper breathe
        // animation / pattern (currently inverted)
        LED_RING(!on);
        brightness_counter++;

        if (on) {
            on_counter++;
        }

    } else {

        if (counter >= 62) {
            counter = 0;
        }

        int n;

        if (counter < 32) {
            n = counter;

        } else {
            n = 62 - counter;
        }

        brightness = (n * n) / 8;
        brightness_counter = 0;
        on_counter = 0;
        counter++;
    }

#endif
}

static uint64_t reboot_time;

/**
   schedule a reboot in time_delta_usec microseconds
 */
void schedule_reboot(uint32_t time_delta_usec)
{
    reboot_time = hrt_absolute_time() + time_delta_usec;
}

/**
   check for a scheduled reboot
 */
static void check_reboot(void)
{
    if (reboot_time != 0 && hrt_absolute_time() > reboot_time) {
        up_systemreset();
    }
}

static void
calculate_fw_crc(void)
{
#define APP_SIZE_MAX 0xf000
#define APP_LOAD_ADDRESS 0x08001000
    // compute CRC of the current firmware
    uint32_t sum = 0;

    for (unsigned p = 0; p < APP_SIZE_MAX; p += 4) {
        uint32_t bytes = *(uint32_t *)(p + APP_LOAD_ADDRESS);
        sum = crc32part((uint8_t *)&bytes, sizeof(bytes), sum);
    }

    r_page_setup[PX4IO_P_SETUP_CRC]   = sum & 0xFFFF;
    r_page_setup[PX4IO_P_SETUP_CRC + 1] = sum >> 16;
}

int
user_start(int argc, char *argv[])
{
    /* configure the first 8 PWM outputs (i.e. all of them) */
    up_pwm_servo_init(0xff);

#if defined(CONFIG_HAVE_CXX) && defined(CONFIG_HAVE_CXXINITIALIZE)

    /* run C++ ctors before we go any further */

    up_cxxinitialize();

#   if defined(CONFIG_SYSTEM_NSH_CXXINITIALIZE)
#       error CONFIG_SYSTEM_NSH_CXXINITIALIZE Must not be defined! Use CONFIG_HAVE_CXX and CONFIG_HAVE_CXXINITIALIZE.
#   endif

#else
#  error platform is dependent on c++ both CONFIG_HAVE_CXX and CONFIG_HAVE_CXXINITIALIZE must be defined.
#endif

    /* reset all to zero */
    memset(&system_state, 0, sizeof(system_state));

    /* configure the high-resolution time/callout interface */
    hrt_init();

    /* calculate our fw CRC so FMU can decide if we need to update */
    calculate_fw_crc();

    /*
     * Poll at 1ms intervals for received bytes that have not triggered
     * a DMA event.
     */
#ifdef CONFIG_ARCH_DMA
    hrt_call_every(&serial_dma_call, 1000, 1000, (hrt_callout)stm32_serial_dma_poll, NULL);
#endif

    /* print some startup info */
    syslog(LOG_INFO, "\nPX4IO: starting\n");

    /* default all the LEDs to off while we start */
    LED_AMBER(false);
    LED_BLUE(false);
    LED_SAFETY(false);
#ifdef GPIO_LED4
    LED_RING(false);
#endif

    /* turn on servo power (if supported) */
#ifdef POWER_SERVO
    POWER_SERVO(true);
#endif

    /* turn off S.Bus out (if supported) */
#ifdef ENABLE_SBUS_OUT
    ENABLE_SBUS_OUT(false);
#endif

    /* start the safety switch handler */
    safety_init();

    /* initialise the control inputs */
    controls_init();

    /* set up the ADC */
    adc_init();

    /* start the FMU interface */
    interface_init();

    /* add a performance counter for mixing */
    perf_counter_t mixer_perf = perf_alloc(PC_ELAPSED, "mix");

    /* add a performance counter for controls */
    perf_counter_t controls_perf = perf_alloc(PC_ELAPSED, "controls");

    /* and one for measuring the loop rate */
    perf_counter_t loop_perf = perf_alloc(PC_INTERVAL, "loop");

    struct mallinfo minfo = mallinfo();
    r_page_status[PX4IO_P_STATUS_FREEMEM] = minfo.mxordblk;
    syslog(LOG_INFO, "MEM: free %u, largest %u\n", minfo.mxordblk, minfo.fordblks);

    /* initialize PWM limit lib */
    output_limit_init(&pwm_limit);

    /*
     *    P O L I C E    L I G H T S
     *
     * Not enough memory, lock down.
     *
     * We might need to allocate mixers later, and this will
     * ensure that a developer doing a change will notice
     * that he just burned the remaining RAM with static
     * allocations. We don't want him to be able to
     * get past that point. This needs to be clearly
     * documented in the dev guide.
     *
     */
    if (minfo.mxordblk < 600) {

        syslog(LOG_ERR, "ERR: not enough MEM");
        bool phase = false;

        while (true) {

            if (phase) {
                LED_AMBER(true);
                LED_BLUE(false);

            } else {
                LED_AMBER(false);
                LED_BLUE(true);
            }

            up_udelay(250000);

            phase = !phase;
        }
    }

    /* Start the failsafe led init */
    failsafe_led_init();

    /*
     * Run everything in a tight loop.
     */

    uint64_t last_debug_time = 0;
    uint64_t last_heartbeat_time = 0;
    uint64_t last_loop_time = 0;

    for (;;) {
        dt = (hrt_absolute_time() - last_loop_time) / 1000000.0f;
        last_loop_time = hrt_absolute_time();

        if (dt < 0.0001f) {
            dt = 0.0001f;

        } else if (dt > 0.02f) {
            dt = 0.02f;
        }

        /* track the rate at which the loop is running */
        perf_count(loop_perf);

        /* kick the mixer */
        perf_begin(mixer_perf);
        mixer_tick();
        perf_end(mixer_perf);

        /* kick the control inputs */
        perf_begin(controls_perf);
        controls_tick();
        perf_end(controls_perf);

        /* some boards such as Pixhawk 2.1 made
           the unfortunate choice to combine the blue led channel with
           the IMU heater. We need a software hack to fix the hardware hack
           by allowing to disable the LED / heater.
         */
        if (r_page_setup[PX4IO_P_SETUP_THERMAL] == PX4IO_THERMAL_IGNORE) {
            /*
              blink blue LED at 4Hz in normal operation. When in
              override blink 4x faster so the user can clearly see
              that override is happening. This helps when
              pre-flight testing the override system
             */
            uint32_t heartbeat_period_us = 250 * 1000UL;

            if (r_status_flags & PX4IO_P_STATUS_FLAGS_OVERRIDE) {
                heartbeat_period_us /= 4;
            }

            if ((hrt_absolute_time() - last_heartbeat_time) > heartbeat_period_us) {
                last_heartbeat_time = hrt_absolute_time();
                heartbeat_blink();
            }

        } else if (r_page_setup[PX4IO_P_SETUP_THERMAL] < PX4IO_THERMAL_FULL) {
            /* switch resistive heater off */
            LED_BLUE(false);

        } else {
            /* switch resistive heater hard on */
            LED_BLUE(true);
        }

        update_mem_usage();

        ring_blink();

        check_reboot();

        /* check for debug activity (default: none) */
        show_debug_messages();

        /* post debug state at ~1Hz - this is via an auxiliary serial port
         * DEFAULTS TO OFF!
         */
        if (hrt_absolute_time() - last_debug_time > (1000 * 1000)) {

            isr_debug(1, "d:%u s=0x%x a=0x%x f=0x%x m=%u",
                  (unsigned)r_page_setup[PX4IO_P_SETUP_SET_DEBUG],
                  (unsigned)r_status_flags,
                  (unsigned)r_setup_arming,
                  (unsigned)r_setup_features,
                  (unsigned)mallinfo().mxordblk);
            last_debug_time = hrt_absolute_time();
        }
    }
}