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/**
 * @file LidarLitePWM.h
 * @author Johan Jansen <jnsn.johan@gmail.com>
 * @author Ban Siesta <bansiesta@gmail.com>
 *
 * Driver for the PulsedLight Lidar-Lite range finders connected via PWM.
 *
 * This driver accesses the pwm_input published by the pwm_input driver.
 */

#include "LidarLitePWM.h"

#ifdef LIDAR_LITE_PWM_SUPPORTED

#include <px4_arch/io_timer.h>

LidarLitePWM::LidarLitePWM(const uint8_t rotation) :
	LidarLite(rotation),
	ScheduledWorkItem(MODULE_NAME, px4::wq_configurations::hp_default)
{
	px4_arch_configgpio(io_timer_channel_get_gpio_output(GPIO_VDD_RANGEFINDER_EN_CHAN));
}

LidarLitePWM::~LidarLitePWM()
{
	stop();
}

int
LidarLitePWM::init()
{
	start();

	return PX4_OK;
}

void
LidarLitePWM::start()
{
	ScheduleOnInterval(get_measure_interval());
}

void
LidarLitePWM::stop()
{
	ScheduleClear();
}

void
LidarLitePWM::Run()
{
	measure();
}

int
LidarLitePWM::measure()
{
	perf_begin(_sample_perf);

	const hrt_abstime timestamp_sample = hrt_absolute_time();

	if (PX4_OK != collect()) {
		PX4_DEBUG("collection error");
		perf_count(_comms_errors);
		perf_end(_sample_perf);
		return PX4_ERROR;
	}

	const float current_distance = float(_pwm.pulse_width) * 1e-3f;   /* 10 usec = 1 cm distance for LIDAR-Lite */

	/* Due to a bug in older versions of the LidarLite firmware, we have to reset sensor on (distance == 0) */
	if (current_distance <= 0.0f) {
		perf_count(_sensor_zero_resets);
		perf_end(_sample_perf);
		return reset_sensor();
	}

	_px4_rangefinder.update(timestamp_sample, current_distance);

	perf_end(_sample_perf);
	return PX4_OK;
}

int
LidarLitePWM::collect()
{
	pwm_input_s pwm_input;

	if (_sub_pwm_input.update(&pwm_input)) {

		_pwm = pwm_input;

		return PX4_OK;
	}

	return EAGAIN;
}

#endif