linux_pwm_out.cpp

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/****************************************************************************
 *
 *   Copyright (c) 2015-2017 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:
 *
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 *    notice, this list of conditions and the following disclaimer.
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 *    used to endorse or promote products derived from this software
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#include <errno.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>

#include <math.h>

#include <px4_platform_common/tasks.h>
#include <px4_platform_common/getopt.h>
#include <px4_platform_common/posix.h>

#include <uORB/Subscription.hpp>
#include <uORB/topics/actuator_controls.h>
#include <uORB/topics/actuator_outputs.h>
#include <uORB/topics/actuator_armed.h>
#include <uORB/topics/rc_channels.h>
#include <uORB/topics/parameter_update.h>

#include <drivers/drv_hrt.h>
#include <drivers/drv_mixer.h>
#include <lib/mixer/MixerGroup.hpp>
#include <lib/mixer/mixer_load.h>
#include <parameters/param.h>
#include <output_limit/output_limit.h>
#include <perf/perf_counter.h>

#include "common.h"
#include "navio_sysfs.h"
#include "PCA9685.h"
#include "ocpoc_mmap.h"
#include "bbblue_pwm_rc.h"

namespace linux_pwm_out
{
static px4_task_t _task_handle = -1;
volatile bool _task_should_exit = false;
static bool _is_running = false;

static char _device[64] = "/sys/class/pwm/pwmchip0";
static char _protocol[64] = "navio";
static int _max_num_outputs = 8; ///< maximum number of outputs the driver should use
static char _mixer_filename[64] = "ROMFS/px4fmu_common/mixers/quad_x.main.mix";

// subscriptions
int     _controls_subs[actuator_controls_s::NUM_ACTUATOR_CONTROL_GROUPS];
int     _armed_sub = -1;

// publications
orb_advert_t    _outputs_pub = nullptr;
orb_advert_t    _rc_pub = nullptr;

perf_counter_t  _perf_control_latency = nullptr;

// topic structures
actuator_controls_s _controls[actuator_controls_s::NUM_ACTUATOR_CONTROL_GROUPS];
orb_id_t            _controls_topics[actuator_controls_s::NUM_ACTUATOR_CONTROL_GROUPS];
actuator_outputs_s  _outputs;
actuator_armed_s    _armed;

// polling
uint8_t _poll_fds_num = 0;
px4_pollfd_struct_t _poll_fds[actuator_controls_s::NUM_ACTUATOR_CONTROL_GROUPS];

// control groups related
uint32_t    _groups_required = 0;
uint32_t    _groups_subscribed = 0;

output_limit_t     _pwm_limit;

// esc parameters
int32_t _pwm_disarmed;
int32_t _pwm_min;
int32_t _pwm_max;

MixerGroup *_mixer_group = nullptr;

static void usage();

static void start();

static void stop();

static void task_main_trampoline(int argc, char *argv[]);

static void subscribe();

static void task_main(int argc, char *argv[]);

static void update_params(Mixer::Airmode &airmode);

/* mixer initialization */
int initialize_mixer(const char *mixer_filename);
int mixer_control_callback(uintptr_t handle, uint8_t control_group, uint8_t control_index, float &input);


int mixer_control_callback(uintptr_t handle,
               uint8_t control_group,
               uint8_t control_index,
               float &input)
{
    const actuator_controls_s *controls = (actuator_controls_s *)handle;
    input = controls[control_group].control[control_index];

    return 0;
}


void update_params(Mixer::Airmode &airmode)
{
    // multicopter air-mode
    param_t param_handle = param_find("MC_AIRMODE");

    if (param_handle != PARAM_INVALID) {
        param_get(param_handle, (int32_t *)&airmode);
    }
}


int initialize_mixer(const char *mixer_filename)
{
    char buf[4096];
    unsigned buflen = sizeof(buf);
    memset(buf, '\0', buflen);

    _mixer_group = new MixerGroup();

    // PX4_INFO("Trying to initialize mixer from config file %s", mixer_filename);

    if (load_mixer_file(mixer_filename, buf, buflen) == 0) {
        if (_mixer_group->load_from_buf(mixer_control_callback, (uintptr_t) &_controls, buf, buflen) == 0) {
            PX4_INFO("Loaded mixer from file %s", mixer_filename);
            return 0;

        } else {
            PX4_ERR("Unable to parse from mixer config file %s", mixer_filename);
        }

    } else {
        PX4_ERR("Unable to load config file %s", mixer_filename);
    }

    if (_mixer_group->count() <= 0) {
        PX4_ERR("Mixer initialization failed");
        return -1;
    }

    return 0;
}


void subscribe()
{
    memset(_controls, 0, sizeof(_controls));
    memset(_poll_fds, 0, sizeof(_poll_fds));

    /* set up ORB topic names */
    _controls_topics[0] = ORB_ID(actuator_controls_0);
    _controls_topics[1] = ORB_ID(actuator_controls_1);
    _controls_topics[2] = ORB_ID(actuator_controls_2);
    _controls_topics[3] = ORB_ID(actuator_controls_3);

    // Subscribe for orb topics
    for (uint8_t i = 0; i < actuator_controls_s::NUM_ACTUATOR_CONTROL_GROUPS; i++) {
        if (_groups_required & (1 << i)) {
            PX4_DEBUG("subscribe to actuator_controls_%d", i);
            _controls_subs[i] = orb_subscribe(_controls_topics[i]);

        } else {
            _controls_subs[i] = -1;
        }

        if (_controls_subs[i] >= 0) {
            _poll_fds[_poll_fds_num].fd = _controls_subs[i];
            _poll_fds[_poll_fds_num].events = POLLIN;
            _poll_fds_num++;
        }

        _armed_sub = orb_subscribe(ORB_ID(actuator_armed));

    }
}

void task_main(int argc, char *argv[])
{
    _is_running = true;

    _perf_control_latency = perf_alloc(PC_ELAPSED, "linux_pwm_out control latency");

    // Set up mixer
    if (initialize_mixer(_mixer_filename) < 0) {
        PX4_ERR("Mixer initialization failed.");
        return;
    }

    PWMOutBase *pwm_out;

    if (strcmp(_protocol, "pca9685") == 0) {
        PX4_INFO("Starting PWM output in PCA9685 mode");
        pwm_out = new PCA9685();

    } else if (strcmp(_protocol, "ocpoc_mmap") == 0) {
        PX4_INFO("Starting PWM output in ocpoc_mmap mode");
        pwm_out = new OcpocMmapPWMOut(_max_num_outputs);

#ifdef __DF_BBBLUE

    } else if (strcmp(_protocol, "bbblue_rc") == 0) {
        PX4_INFO("Starting PWM output in bbblue_rc mode");
        pwm_out = new BBBlueRcPWMOut(_max_num_outputs);
#endif

    } else { /* navio */
        PX4_INFO("Starting PWM output in Navio mode");
        pwm_out = new NavioSysfsPWMOut(_device, _max_num_outputs);
    }

    if (pwm_out->init() != 0) {
        PX4_ERR("PWM output init failed");
        delete pwm_out;
        return;
    }

    _mixer_group->groups_required(_groups_required);

    // subscribe and set up polling
    subscribe();

    Mixer::Airmode airmode = Mixer::Airmode::disabled;
    update_params(airmode);
    uORB::Subscription parameter_update_sub{ORB_ID(parameter_update)};

    int rc_channels_sub = -1;

    // Start disarmed
    _armed.armed = false;
    _armed.prearmed = false;

    output_limit_init(&_pwm_limit);

    while (!_task_should_exit) {

        bool updated;
        orb_check(_armed_sub, &updated);

        if (updated) {
            orb_copy(ORB_ID(actuator_armed), _armed_sub, &_armed);
        }

        if (_mixer_group) {
            _mixer_group->set_airmode(airmode);
        }

        int pret = px4_poll(_poll_fds, _poll_fds_num, 10);

        /* Timed out, do a periodic check for _task_should_exit. */
        if (pret == 0 && !_armed.in_esc_calibration_mode) {
            continue;
        }

        /* This is undesirable but not much we can do. */
        if (pret < 0) {
            PX4_WARN("poll error %d, %d", pret, errno);
            /* sleep a bit before next try */
            usleep(10000);
            continue;
        }

        /* get controls for required topics */
        unsigned poll_id = 0;

        for (uint8_t i = 0; i < actuator_controls_s::NUM_ACTUATOR_CONTROL_GROUPS; i++) {
            if (_controls_subs[i] >= 0) {
                if (_poll_fds[poll_id].revents & POLLIN) {
                    orb_copy(_controls_topics[i], _controls_subs[i], &_controls[i]);
                }

                poll_id++;
            }
        }

        if (_armed.in_esc_calibration_mode) {
            if (rc_channels_sub == -1) {
                // only subscribe when really needed: esc calibration is not something we use regularily
                rc_channels_sub = orb_subscribe(ORB_ID(rc_channels));
            }

            rc_channels_s rc_channels;
            int ret = orb_copy(ORB_ID(rc_channels), rc_channels_sub, &rc_channels);
            _controls[0].control[0] = 0.f;
            _controls[0].control[1] = 0.f;
            _controls[0].control[2] = 0.f;
            int channel = rc_channels.function[rc_channels_s::RC_CHANNELS_FUNCTION_THROTTLE];

            if (ret == 0 && channel >= 0 && channel < (int)(sizeof(rc_channels.channels) / sizeof(rc_channels.channels[0]))) {
                _controls[0].control[3] = rc_channels.channels[channel];

            } else {
                _controls[0].control[3] = 1.f;
            }

            /* Switch off the PWM limit ramp for the calibration. */
            _pwm_limit.state = OUTPUT_LIMIT_STATE_ON;
        }

        if (_mixer_group != nullptr) {
            /* do mixing */
            _outputs.noutputs = _mixer_group->mix(_outputs.output, actuator_outputs_s::NUM_ACTUATOR_OUTPUTS);

            /* disable unused ports by setting their output to NaN */
            for (size_t i = _outputs.noutputs; i < _outputs.NUM_ACTUATOR_OUTPUTS; i++) {
                _outputs.output[i] = NAN;
            }

            const uint16_t reverse_mask = 0;
            uint16_t disarmed_pwm[actuator_outputs_s::NUM_ACTUATOR_OUTPUTS];
            uint16_t min_pwm[actuator_outputs_s::NUM_ACTUATOR_OUTPUTS];
            uint16_t max_pwm[actuator_outputs_s::NUM_ACTUATOR_OUTPUTS];

            for (unsigned int i = 0; i < actuator_outputs_s::NUM_ACTUATOR_OUTPUTS; i++) {
                disarmed_pwm[i] = _pwm_disarmed;
                min_pwm[i] = _pwm_min;
                max_pwm[i] = _pwm_max;
            }

            uint16_t pwm[actuator_outputs_s::NUM_ACTUATOR_OUTPUTS];

            // TODO FIXME: pre-armed seems broken
            output_limit_calc(_armed.armed,
                      false/*_armed.prearmed*/,
                      _outputs.noutputs,
                      reverse_mask,
                      disarmed_pwm,
                      min_pwm,
                      max_pwm,
                      _outputs.output,
                      pwm,
                      &_pwm_limit);

            if (_armed.lockdown || _armed.manual_lockdown) {
                pwm_out->send_output_pwm(disarmed_pwm, _outputs.noutputs);

            } else if (_armed.in_esc_calibration_mode) {

                uint16_t pwm_value;

                if (_controls[0].control[3] > 0.5f) { // use throttle to decide which value to use
                    pwm_value = _pwm_max;

                } else {
                    pwm_value = _pwm_min;
                }

                for (uint32_t i = 0; i < _outputs.noutputs; ++i) {
                    pwm[i] = pwm_value;
                }

                pwm_out->send_output_pwm(pwm, _outputs.noutputs);

            } else {
                pwm_out->send_output_pwm(pwm, _outputs.noutputs);
            }

            _outputs.timestamp = hrt_absolute_time();

            if (_outputs_pub != nullptr) {
                orb_publish(ORB_ID(actuator_outputs), _outputs_pub, &_outputs);

            } else {
                _outputs_pub = orb_advertise(ORB_ID(actuator_outputs), &_outputs);
            }

            // use first valid timestamp_sample for latency tracking
            for (int i = 0; i < actuator_controls_s::NUM_ACTUATOR_CONTROL_GROUPS; i++) {
                const bool required = _groups_required & (1 << i);
                const hrt_abstime &timestamp_sample = _controls[i].timestamp_sample;

                if (required && (timestamp_sample > 0)) {
                    perf_set_elapsed(_perf_control_latency, _outputs.timestamp - timestamp_sample);
                    break;
                }
            }

        } else {
            PX4_ERR("Could not mix output! Exiting...");
            _task_should_exit = true;
        }

        // check for parameter updates
        if (parameter_update_sub.updated()) {
            // clear update
            parameter_update_s pupdate;
            parameter_update_sub.copy(&pupdate);

            // update parameters from storage
            update_params(airmode);
        }
    }

    delete pwm_out;

    for (uint8_t i = 0; i < actuator_controls_s::NUM_ACTUATOR_CONTROL_GROUPS; i++) {
        if (_controls_subs[i] >= 0) {
            orb_unsubscribe(_controls_subs[i]);
        }
    }

    if (_armed_sub != -1) {
        orb_unsubscribe(_armed_sub);
        _armed_sub = -1;
    }

    if (rc_channels_sub != -1) {
        orb_unsubscribe(rc_channels_sub);
    }

    perf_free(_perf_control_latency);

    _is_running = false;

}

void task_main_trampoline(int argc, char *argv[])
{
    task_main(argc, argv);
}

void start()
{
    _task_should_exit = false;

    /* start the task */
    _task_handle = px4_task_spawn_cmd("pwm_out_main",
                      SCHED_DEFAULT,
                      SCHED_PRIORITY_MAX,
                      1500,
                      (px4_main_t)&task_main_trampoline,
                      nullptr);

    if (_task_handle < 0) {
        PX4_ERR("task start failed");
        return;
    }

}

void stop()
{
    _task_should_exit = true;

    while (_is_running) {
        usleep(200000);
        PX4_INFO(".");
    }

    _task_handle = -1;
}

void usage()
{
    PX4_INFO("usage: pwm_out start [-d pwmdevice] [-m mixerfile] [-p protocol]");
    PX4_INFO("       -d pwmdevice : sysfs device for pwm generation (only for Navio)");
    PX4_INFO("                       (default /sys/class/pwm/pwmchip0)");
    PX4_INFO("       -m mixerfile : path to mixerfile");
    PX4_INFO("                       (default ROMFS/px4fmu_common/mixers/quad_x.main.mix)");
    PX4_INFO("       -p protocol : driver output protocol (navio|pca9685|ocpoc_mmap|bbblue_rc)");
    PX4_INFO("                       (default is navio)");
    PX4_INFO("       -n num_outputs : maximum number of outputs the driver should use");
    PX4_INFO("                       (default is 8)");
    PX4_INFO("       pwm_out stop");
    PX4_INFO("       pwm_out status");
}

} // namespace linux_pwm_out

/* driver 'main' command */
extern "C" __EXPORT int linux_pwm_out_main(int argc, char *argv[]);

int linux_pwm_out_main(int argc, char *argv[])
{
    int ch;
    int myoptind = 1;
    const char *myoptarg = nullptr;

    char *verb = nullptr;

    if (argc >= 2) {
        verb = argv[1];

    } else {
        return 1;
    }

    while ((ch = px4_getopt(argc, argv, "d:m:p:n:", &myoptind, &myoptarg)) != EOF) {
        switch (ch) {
        case 'd':
            strncpy(linux_pwm_out::_device, myoptarg, sizeof(linux_pwm_out::_device));
            break;

        case 'm':
            strncpy(linux_pwm_out::_mixer_filename, myoptarg, sizeof(linux_pwm_out::_mixer_filename));
            break;

        case 'p':
            strncpy(linux_pwm_out::_protocol, myoptarg, sizeof(linux_pwm_out::_protocol));
            break;

        case 'n': {
                unsigned long max_num = strtoul(myoptarg, nullptr, 10);

                if (max_num <= 0) {
                    max_num = 8;
                }

                if (max_num > actuator_outputs_s::NUM_ACTUATOR_OUTPUTS) {
                    max_num = actuator_outputs_s::NUM_ACTUATOR_OUTPUTS;
                }

                linux_pwm_out::_max_num_outputs = max_num;
            }
            break;
        }
    }

    /** gets the parameters for the esc's pwm */
    param_get(param_find("PWM_DISARMED"), &linux_pwm_out::_pwm_disarmed);
    param_get(param_find("PWM_MIN"), &linux_pwm_out::_pwm_min);
    param_get(param_find("PWM_MAX"), &linux_pwm_out::_pwm_max);

    /*
     * Start/load the driver.
     */
    if (!strcmp(verb, "start")) {
        if (linux_pwm_out::_is_running) {
            PX4_WARN("pwm_out already running");
            return 1;
        }

        linux_pwm_out::start();
    }

    else if (!strcmp(verb, "stop")) {
        if (!linux_pwm_out::_is_running) {
            PX4_WARN("pwm_out is not running");
            return 1;
        }

        linux_pwm_out::stop();
    }

    else if (!strcmp(verb, "status")) {
        PX4_WARN("pwm_out is %s", linux_pwm_out::_is_running ? "running" : "not running");
        return 0;

    } else {
        linux_pwm_out::usage();
        return 1;
    }

    return 0;
}