PWMSim.cpp

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#include "PWMSim.hpp"

#include <mathlib/mathlib.h>
#include <px4_platform_common/getopt.h>

#include <uORB/Subscription.hpp>
#include <uORB/topics/parameter_update.h>

PWMSim::PWMSim(bool hil_mode_enabled) :
    CDev(PWM_OUTPUT0_DEVICE_PATH),
    OutputModuleInterface(MODULE_NAME, px4::wq_configurations::hp_default)
{
    _mixing_output.setAllDisarmedValues(PWM_SIM_DISARMED_MAGIC);
    _mixing_output.setAllFailsafeValues(PWM_SIM_FAILSAFE_MAGIC);
    _mixing_output.setAllMinValues(PWM_SIM_PWM_MIN_MAGIC);
    _mixing_output.setAllMaxValues(PWM_SIM_PWM_MAX_MAGIC);

    _mixing_output.setIgnoreLockdown(hil_mode_enabled);

    CDev::init();
}

void
PWMSim::Run()
{
    if (should_exit()) {
        ScheduleClear();
        _mixing_output.unregister();

        exit_and_cleanup();
        return;
    }

    _mixing_output.update();

    // check for parameter updates
    if (_parameter_update_sub.updated()) {
        parameter_update_s pupdate;
        _parameter_update_sub.copy(&pupdate);
        updateParams();
    }

    // check at end of cycle (updateSubscriptions() can potentially change to a different WorkQueue thread)
    _mixing_output.updateSubscriptions(true);
}

bool
PWMSim::updateOutputs(bool stop_motors, uint16_t outputs[MAX_ACTUATORS], unsigned num_outputs,
              unsigned num_control_groups_updated)
{
    // Nothing to do, as we are only interested in the actuator_outputs topic publication.
    // That should only be published once we receive actuator_controls (important for lock-step to work correctly)
    return num_control_groups_updated > 0;
}

int
PWMSim::ioctl(device::file_t *filp, int cmd, unsigned long arg)
{
    int ret = OK;

    lock();

    switch (cmd) {
    case PWM_SERVO_ARM:
        break;

    case PWM_SERVO_DISARM:
        break;

    case PWM_SERVO_SET_MIN_PWM: {
            struct pwm_output_values *pwm = (struct pwm_output_values *)arg;

            for (unsigned i = 0; i < pwm->channel_count; i++) {
                if (i < OutputModuleInterface::MAX_ACTUATORS) {
                    _mixing_output.minValue(i) = pwm->values[i];
                }
            }

            break;
        }

    case PWM_SERVO_SET_MAX_PWM: {
            struct pwm_output_values *pwm = (struct pwm_output_values *)arg;

            for (unsigned i = 0; i < pwm->channel_count; i++) {
                if (i < OutputModuleInterface::MAX_ACTUATORS) {
                    _mixing_output.maxValue(i) = pwm->values[i];
                }
            }

            break;
        }

    case PWM_SERVO_SET_UPDATE_RATE:
        // PWMSim does not limit the update rate
        break;

    case PWM_SERVO_SET_SELECT_UPDATE_RATE:
        break;

    case PWM_SERVO_GET_DEFAULT_UPDATE_RATE:
        *(uint32_t *)arg = 9999;
        break;

    case PWM_SERVO_GET_UPDATE_RATE:
        *(uint32_t *)arg = 9999;
        break;

    case PWM_SERVO_GET_SELECT_UPDATE_RATE:
        *(uint32_t *)arg = 0;
        break;

    case PWM_SERVO_GET_FAILSAFE_PWM: {
            struct pwm_output_values *pwm = (struct pwm_output_values *)arg;

            for (unsigned i = 0; i < OutputModuleInterface::MAX_ACTUATORS; i++) {
                pwm->values[i] = _mixing_output.failsafeValue(i);
            }

            pwm->channel_count = OutputModuleInterface::MAX_ACTUATORS;
            break;
        }

    case PWM_SERVO_GET_DISARMED_PWM: {
            struct pwm_output_values *pwm = (struct pwm_output_values *)arg;

            for (unsigned i = 0; i < OutputModuleInterface::MAX_ACTUATORS; i++) {
                pwm->values[i] = _mixing_output.disarmedValue(i);
            }

            pwm->channel_count = OutputModuleInterface::MAX_ACTUATORS;
            break;
        }

    case PWM_SERVO_GET_MIN_PWM: {
            struct pwm_output_values *pwm = (struct pwm_output_values *)arg;

            for (unsigned i = 0; i < OutputModuleInterface::MAX_ACTUATORS; i++) {
                pwm->values[i] = _mixing_output.minValue(i);
            }

            pwm->channel_count = OutputModuleInterface::MAX_ACTUATORS;
            break;
        }

    case PWM_SERVO_GET_TRIM_PWM: {
            struct pwm_output_values *pwm = (struct pwm_output_values *)arg;

            for (unsigned i = 0; i < OutputModuleInterface::MAX_ACTUATORS; i++) {
                pwm->values[i] = (_mixing_output.maxValue(i) + _mixing_output.minValue(i)) / 2;
            }

            pwm->channel_count = OutputModuleInterface::MAX_ACTUATORS;
            break;
        }

    case PWM_SERVO_GET_MAX_PWM: {
            struct pwm_output_values *pwm = (struct pwm_output_values *)arg;

            for (unsigned i = 0; i < OutputModuleInterface::MAX_ACTUATORS; i++) {
                pwm->values[i] = _mixing_output.maxValue(i);
            }

            pwm->channel_count = OutputModuleInterface::MAX_ACTUATORS;
            break;
        }

    case PWM_SERVO_GET_RATEGROUP(0) ... PWM_SERVO_GET_RATEGROUP(PWM_OUTPUT_MAX_CHANNELS - 1): {
            // no restrictions on output grouping
            unsigned channel = cmd - PWM_SERVO_GET_RATEGROUP(0);

            *(uint32_t *)arg = (1 << channel);
            break;
        }

    case PWM_SERVO_GET_COUNT:
        *(unsigned *)arg = OutputModuleInterface::MAX_ACTUATORS;
        break;

    case MIXERIOCRESET:
        _mixing_output.resetMixerThreadSafe();
        break;

    case MIXERIOCLOADBUF: {
            const char *buf = (const char *)arg;
            unsigned buflen = strlen(buf);
            ret = _mixing_output.loadMixerThreadSafe(buf, buflen);
            break;
        }


    default:
        ret = -ENOTTY;
        break;
    }

    unlock();

    return ret;
}

int
PWMSim::task_spawn(int argc, char *argv[])
{
    bool hil_mode = false;

    int myoptind = 1;
    int ch;
    const char *myoptarg = nullptr;

    while ((ch = px4_getopt(argc, argv, "m:", &myoptind, &myoptarg)) != EOF) {
        switch (ch) {
        case 'm':
            hil_mode = strcmp(myoptarg, "hil") == 0;
            break;

        default:
            return print_usage("unrecognized flag");
        }
    }

    PWMSim *instance = new PWMSim(hil_mode);

    if (!instance) {
        PX4_ERR("alloc failed");
        return -1;
    }

    _object.store(instance);
    _task_id = task_id_is_work_queue;
    instance->ScheduleNow();
    return 0;
}

int PWMSim::custom_command(int argc, char *argv[])
{
    return print_usage("unknown command");
}

int PWMSim::print_status()
{
    _mixing_output.printStatus();
    return 0;
}

int PWMSim::print_usage(const char *reason)
{
    if (reason) {
        PX4_WARN("%s\n", reason);
    }

    PRINT_MODULE_DESCRIPTION(
        R"DESCR_STR(
### Description
Driver for simulated PWM outputs.

Its only function is to take `actuator_control` uORB messages,
mix them with any loaded mixer and output the result to the
`actuator_output` uORB topic.

It is used in SITL and HITL.

)DESCR_STR");

    PRINT_MODULE_USAGE_NAME("pwm_out_sim", "driver");
    PRINT_MODULE_USAGE_COMMAND_DESCR("start", "Start the module");
    PRINT_MODULE_USAGE_PARAM_STRING('m', "sim", "hil|sim", "Mode", true);
    PRINT_MODULE_USAGE_DEFAULT_COMMANDS();

    return 0;
}

extern "C" __EXPORT int pwm_out_sim_main(int argc, char *argv[])
{
    return PWMSim::main(argc, argv);
}