/*
 * This file is free software: you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This file is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * Code by Andrew Tridgell and Siddharth Bharat Purohit
 */
#include <AP_HAL/AP_HAL.h>
#include "ch.h"
#include "hal.h"

#if HAL_USE_ADC == TRUE && !defined(HAL_DISABLE_ADC_DRIVER)

#include "AnalogIn.h"

#if HAL_WITH_IO_MCU
#include <AP_IOMCU/AP_IOMCU.h>
extern AP_IOMCU iomcu;
#endif

#include "hwdef/common/stm32_util.h"

#ifndef CHIBIOS_ADC_MAVLINK_DEBUG
// this allows the first 6 analog channels to be reported by mavlink for debugging purposes
#define CHIBIOS_ADC_MAVLINK_DEBUG 0
#endif

// MAVLink is included as we send a mavlink message as part of debug,
// and also use the MAV_POWER flags below in update_power_flags
#include <GCS_MAVLink/GCS_MAVLink.h>

#define ANLOGIN_DEBUGGING 0

// base voltage scaling for 12 bit 3.3V ADC
#define VOLTAGE_SCALING (3.3f/(1<<12))

#if ANLOGIN_DEBUGGING
 # define Debug(fmt, args ...)  do {printf("%s:%d: " fmt "\n", __FUNCTION__, __LINE__, ## args); } while(0)
#else
 # define Debug(fmt, args ...)
#endif

extern const AP_HAL::HAL& hal;

using namespace ChibiOS;

// special pins
#define ANALOG_SERVO_VRSSI_PIN 103

/*
  scaling table between ADC count and actual input voltage, to account
  for voltage dividers on the board.
 */
const AnalogIn::pin_info AnalogIn::pin_config[] = HAL_ANALOG_PINS;

#define ADC_GRP1_NUM_CHANNELS   ARRAY_SIZE(AnalogIn::pin_config)

// samples filled in by ADC DMA engine
adcsample_t *AnalogIn::samples;
uint32_t AnalogIn::sample_sum[ADC_GRP1_NUM_CHANNELS];
uint32_t AnalogIn::sample_count;

AnalogSource::AnalogSource(int16_t pin) :
    _pin(pin)
{
}


float AnalogSource::read_average()
{
    WITH_SEMAPHORE(_semaphore);

    if (_sum_count == 0) {
        return _value;
    }
    _value = _sum_value / _sum_count;
    _value_ratiometric = _sum_ratiometric / _sum_count;
    _sum_value = 0;
    _sum_ratiometric = 0;
    _sum_count = 0;

    return _value;
}

float AnalogSource::read_latest()
{
    return _latest_value;
}

/*
  return scaling from ADC count to Volts
 */
float AnalogSource::_pin_scaler(void)
{
    float scaling = VOLTAGE_SCALING;
    for (uint8_t i=0; i<ADC_GRP1_NUM_CHANNELS; i++) {
        if (AnalogIn::pin_config[i].channel == _pin) {
            scaling = AnalogIn::pin_config[i].scaling;
            break;
        }
    }
    return scaling;
}

/*
  return voltage in Volts
 */
float AnalogSource::voltage_average()
{
    return _pin_scaler() * read_average();
}

/*
  return voltage in Volts, assuming a ratiometric sensor powered by
  the 5V rail
 */
float AnalogSource::voltage_average_ratiometric()
{
    voltage_average();
    return _pin_scaler() * _value_ratiometric;
}

/*
  return voltage in Volts
 */
float AnalogSource::voltage_latest()
{
    return _pin_scaler() * read_latest();
}

void AnalogSource::set_pin(uint8_t pin)
{
    if (_pin == pin) {
        return;
    }
    WITH_SEMAPHORE(_semaphore);
    _pin = pin;
    _sum_value = 0;
    _sum_ratiometric = 0;
    _sum_count = 0;
    _latest_value = 0;
    _value = 0;
    _value_ratiometric = 0;
}

/*
  apply a reading in ADC counts
 */
void AnalogSource::_add_value(float v, float vcc5V)
{
    WITH_SEMAPHORE(_semaphore);

    _latest_value = v;
    _sum_value += v;
    if (vcc5V < 3.0f) {
        _sum_ratiometric += v;
    } else {
        // this compensates for changes in the 5V rail relative to the
        // 3.3V reference used by the ADC.
        _sum_ratiometric += v * 5.0f / vcc5V;
    }
    _sum_count++;
    if (_sum_count == 254) {
        _sum_value /= 2;
        _sum_ratiometric /= 2;
        _sum_count /= 2;
    }
}


/*
  callback from ADC driver when sample buffer is filled
 */
void AnalogIn::adccallback(ADCDriver *adcp)
{
    const adcsample_t *buffer = samples;

    stm32_cacheBufferInvalidate(buffer, sizeof(adcsample_t)*ADC_DMA_BUF_DEPTH*ADC_GRP1_NUM_CHANNELS);
    for (uint8_t i = 0; i < ADC_DMA_BUF_DEPTH; i++) {
        for (uint8_t j = 0; j < ADC_GRP1_NUM_CHANNELS; j++) {
            sample_sum[j] += *buffer++;
        }
    }
    sample_count += ADC_DMA_BUF_DEPTH;
}

/*
  setup adc peripheral to capture samples with DMA into a buffer
 */
void AnalogIn::init()
{
    if (ADC_GRP1_NUM_CHANNELS == 0) {
        return;
    }

    samples = (adcsample_t *)hal.util->malloc_type(sizeof(adcsample_t)*ADC_DMA_BUF_DEPTH*ADC_GRP1_NUM_CHANNELS, AP_HAL::Util::MEM_DMA_SAFE);

    adcStart(&ADCD1, NULL);
    memset(&adcgrpcfg, 0, sizeof(adcgrpcfg));
    adcgrpcfg.circular = true;
    adcgrpcfg.num_channels = ADC_GRP1_NUM_CHANNELS;
    adcgrpcfg.end_cb = adccallback;
#if defined(STM32H7)
    // use 12 bits resolution to keep scaling factors the same as other boards.
    // todo: enable oversampling in cfgr2 ?
    adcgrpcfg.cfgr = ADC_CFGR_CONT | ADC_CFGR_RES_12BITS;
#else
    adcgrpcfg.sqr1 = ADC_SQR1_NUM_CH(ADC_GRP1_NUM_CHANNELS);
    adcgrpcfg.cr2 = ADC_CR2_SWSTART;
#endif

    for (uint8_t i=0; i<ADC_GRP1_NUM_CHANNELS; i++) {
        uint8_t chan = pin_config[i].channel;
        // setup cycles per sample for the channel
#if defined(STM32H7)
        adcgrpcfg.pcsel |= (1<<chan);
        adcgrpcfg.smpr[chan/10] |= ADC_SMPR_SMP_384P5 << (3*(chan%10));
        if (i < 4) {
            adcgrpcfg.sqr[0] |= chan << (6*(i+1));
        } else if (i < 9) {
            adcgrpcfg.sqr[1] |= chan << (6*(i-4));
        } else {
            adcgrpcfg.sqr[2] |= chan << (6*(i-9));
        }
#else
        if (chan < 10) {
            adcgrpcfg.smpr2 |= ADC_SAMPLE_480 << (3*chan);
        } else {
            adcgrpcfg.smpr1 |= ADC_SAMPLE_480 << (3*(chan-10));
        }
        // setup channel sequence
        if (i < 6) {
            adcgrpcfg.sqr3 |= chan << (5*i);
        } else if (i < 12) {
            adcgrpcfg.sqr2 |= chan << (5*(i-6));
        } else {
            adcgrpcfg.sqr1 |= chan << (5*(i-12));
        }
#endif
    }
    adcStartConversion(&ADCD1, &adcgrpcfg, samples, ADC_DMA_BUF_DEPTH);
}

/*
  calculate average sample since last read for all channels
 */
void AnalogIn::read_adc(uint32_t *val)
{
    chSysLock();
    for (uint8_t i = 0; i < ADC_GRP1_NUM_CHANNELS; i++) {
        val[i] = sample_sum[i] / sample_count;
    }
    memset(sample_sum, 0, sizeof(sample_sum));
    sample_count = 0;
    chSysUnlock();
}

/*
  called at 1kHz
 */
void AnalogIn::_timer_tick(void)
{
    // read adc at 100Hz
    uint32_t now = AP_HAL::micros();
    uint32_t delta_t = now - _last_run;
    if (delta_t < 10000) {
        return;
    }
    _last_run = now;

    uint32_t buf_adc[ADC_GRP1_NUM_CHANNELS];

    /* read all channels available */
    read_adc(buf_adc);

    // update power status flags
    update_power_flags();

    // match the incoming channels to the currently active pins
    for (uint8_t i=0; i < ADC_GRP1_NUM_CHANNELS; i++) {
#ifdef ANALOG_VCC_5V_PIN
        if (pin_config[i].channel == ANALOG_VCC_5V_PIN) {
            // record the Vcc value for later use in
            // voltage_average_ratiometric()
            _board_voltage = buf_adc[i] * pin_config[i].scaling;
        }
#endif
#ifdef FMU_SERVORAIL_ADC_CHAN
        if (pin_config[i].channel == FMU_SERVORAIL_ADC_CHAN) {
           _servorail_voltage = buf_adc[i] * pin_config[i].scaling;
        }
#endif
    }

#if HAL_WITH_IO_MCU
    // now handle special inputs from IOMCU
    _servorail_voltage = iomcu.get_vservo();
    _rssi_voltage = iomcu.get_vrssi();
#endif

    for (uint8_t i=0; i<ADC_GRP1_NUM_CHANNELS; i++) {
        Debug("chan %u value=%u\n",
              (unsigned)pin_config[i].channel,
              (unsigned)buf_adc[i]);
        for (uint8_t j=0; j < ANALOG_MAX_CHANNELS; j++) {
            ChibiOS::AnalogSource *c = _channels[j];
            if (c != nullptr) {
                if (pin_config[i].channel == c->_pin) {
                    // add a value
                    c->_add_value(buf_adc[i], _board_voltage);
                } else if (c->_pin == ANALOG_SERVO_VRSSI_PIN) {
                    c->_add_value(_rssi_voltage / VOLTAGE_SCALING, 0);
                }
            }
        }
    }

#if CHIBIOS_ADC_MAVLINK_DEBUG
    static uint8_t count;
    if (AP_HAL::millis() > 5000 && count++ == 10) {
        count = 0;
        uint16_t adc[6] {};
        uint8_t n = ADC_GRP1_NUM_CHANNELS;
        if (n > 6) {
            n = 6;
        }
        for (uint8_t i=0; i < n; i++) {
            adc[i] = buf_adc[i];
        }
        mavlink_msg_ap_adc_send(MAVLINK_COMM_0, adc[0], adc[1], adc[2], adc[3], adc[4], adc[5]);
    }
#endif
}

AP_HAL::AnalogSource* AnalogIn::channel(int16_t pin)
{
    for (uint8_t j=0; j<ANALOG_MAX_CHANNELS; j++) {
        if (_channels[j] == nullptr) {
            _channels[j] = new AnalogSource(pin);
            return _channels[j];
        }
    }
    hal.console->printf("Out of analog channels\n");
    return nullptr;
}

/*
  update power status flags
 */
void AnalogIn::update_power_flags(void)
{
    uint16_t flags = 0;

    /*
      primary "brick" power supply valid pin. Some boards have this
      active high, some active low. Use nVALID for active low, VALID
      for active high
    */
#if defined(HAL_GPIO_PIN_VDD_BRICK_VALID)
    if (palReadLine(HAL_GPIO_PIN_VDD_BRICK_VALID) == 1) {
        flags |= MAV_POWER_STATUS_BRICK_VALID;
    }
#elif defined(HAL_GPIO_PIN_VDD_BRICK_nVALID)
    if (palReadLine(HAL_GPIO_PIN_VDD_BRICK_nVALID) == 0) {
        flags |= MAV_POWER_STATUS_BRICK_VALID;
    }
#endif

    /*
      secondary "brick" power supply valid pin. This is servo rail
      power valid on some boards. Some boards have this active high,
      some active low. Use nVALID for active low, VALID for active
      high. This maps to the MAV_POWER_STATUS_SERVO_VALID in mavlink
      (as this was first added for older boards that used servo rail
      for backup power)
    */
#if defined(HAL_GPIO_PIN_VDD_BRICK2_VALID)
    if (palReadLine(HAL_GPIO_PIN_VDD_BRICK_VALID) == 1) {
        flags |= MAV_POWER_STATUS_SERVO_VALID;
    }
#elif defined(HAL_GPIO_PIN_VDD_BRICK2_nVALID)
    if (palReadLine(HAL_GPIO_PIN_VDD_BRICK2_nVALID) == 0) {
        flags |= MAV_POWER_STATUS_SERVO_VALID;
    }
#endif

    /*
      USB power. This can be VBUS_VALID, VBUS_nVALID or just
      VBUS. Some boards have both a valid pin and VBUS. The VBUS pin
      is an analog pin that could be used to read USB voltage.
     */
#if defined(HAL_GPIO_PIN_VBUS_VALID)
    if (palReadLine(HAL_GPIO_PIN_VBUS_VALID) == 1) {
        flags |= MAV_POWER_STATUS_USB_CONNECTED;
    }
#elif defined(HAL_GPIO_PIN_VBUS_nVALID)
    if (palReadLine(HAL_GPIO_PIN_VBUS_nVALID) == 0) {
        flags |= MAV_POWER_STATUS_USB_CONNECTED;
    }
#elif defined(HAL_GPIO_PIN_VBUS)
    if (palReadLine(HAL_GPIO_PIN_VBUS) == 1) {
        flags |= MAV_POWER_STATUS_USB_CONNECTED;
    }
#endif

    /*
      overcurrent on "high power" peripheral rail.
     */
#if defined(HAL_GPIO_PIN_VDD_5V_HIPOWER_OC)
    if (palReadLine(HAL_GPIO_PIN_VDD_5V_HIPOWER_OC) == 1) {
        flags |= MAV_POWER_STATUS_PERIPH_HIPOWER_OVERCURRENT;
    }
#elif defined(HAL_GPIO_PIN_VDD_5V_HIPOWER_nOC)
    if (palReadLine(HAL_GPIO_PIN_VDD_5V_HIPOWER_nOC) == 0) {
        flags |= MAV_POWER_STATUS_PERIPH_HIPOWER_OVERCURRENT;
    }
#endif

    /*
      overcurrent on main peripheral rail.
     */
#if defined(HAL_GPIO_PIN_VDD_5V_PERIPH_OC)
    if (palReadLine(HAL_GPIO_PIN_VDD_5V_PERIPH_OC) == 1) {
        flags |= MAV_POWER_STATUS_PERIPH_OVERCURRENT;
    }
#elif defined(HAL_GPIO_PIN_VDD_5V_PERIPH_nOC)
    if (palReadLine(HAL_GPIO_PIN_VDD_5V_PERIPH_nOC) == 0) {
        flags |= MAV_POWER_STATUS_PERIPH_OVERCURRENT;
    }
#endif

#if defined(HAL_GPIO_PIN_VDD_SERVO_VALID)
#error "building with old hwdef.dat"
#endif

#if 0
    /*
      this bit of debug code is useful when testing the polarity of
      VALID pins for power sources. It allows you to see the change on
      USB with a 3s delay, so you can see USB changes by unplugging
      and re-inserting USB power
     */
    static uint32_t last_change_ms;
    uint32_t now = AP_HAL::millis();
    if (_power_flags != flags) {
        if (last_change_ms == 0) {
            last_change_ms = now;
        } else if (now - last_change_ms > 3000) {
            last_change_ms = 0;
            hal.console->printf("POWR: 0x%02x -> 0x%02x\n", _power_flags, flags);
            _power_flags = flags;
        }
        if (hal.util->get_soft_armed()) {
            // the power status has changed while armed
            flags |= MAV_POWER_STATUS_CHANGED;
        }
        return;
    }
#endif

    if (_power_flags != 0 &&
        _power_flags != flags &&
        hal.util->get_soft_armed()) {
        // the power status has changed while armed
        flags |= MAV_POWER_STATUS_CHANGED;
    }
    _accumulated_power_flags |= flags;
    _power_flags = flags;
}
#endif // HAL_USE_ADC