betaflight/src/main/drivers/pwm_output_dshot.c

/*
 * This file is part of Cleanflight and Betaflight.
 *
 * Cleanflight and Betaflight are free software. You can redistribute
 * this software and/or modify this software 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.
 *
 * Cleanflight and Betaflight are distributed in the hope that they
 * 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 software.
 *
 * If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdbool.h>
#include <stdint.h>
#include <math.h>

#include "platform.h"

#ifdef USE_DSHOT

#include "build/debug.h"

#include "drivers/io.h"
#include "timer.h"
#if defined(STM32F4)
#include "stm32f4xx.h"
#elif defined(STM32F3)
#include "stm32f30x.h"
#endif
#include "pwm_output.h"
#include "drivers/nvic.h"
#include "dma.h"
#include "rcc.h"

static uint8_t dmaMotorTimerCount = 0;
static motorDmaTimer_t dmaMotorTimers[MAX_DMA_TIMERS];
static motorDmaOutput_t dmaMotors[MAX_SUPPORTED_MOTORS];

motorDmaOutput_t *getMotorDmaOutput(uint8_t index)
{
    return &dmaMotors[index];
}

uint8_t getTimerIndex(TIM_TypeDef *timer)
{
    for (int i = 0; i < dmaMotorTimerCount; i++) {
        if (dmaMotorTimers[i].timer == timer) {
            return i;
        }
    }
    dmaMotorTimers[dmaMotorTimerCount++].timer = timer;
    return dmaMotorTimerCount-1;
}

void pwmWriteDshotInt(uint8_t index, uint16_t value)
{
    motorDmaOutput_t *const motor = &dmaMotors[index];

    if (!motor->configured) {
        return;
    }

    uint16_t packet = prepareDshotPacket(motor, value);
    uint8_t bufferSize;

#ifdef USE_DSHOT_DMAR
    if (useBurstDshot) {
        bufferSize = loadDmaBuffer(&motor->timer->dmaBurstBuffer[timerLookupChannelIndex(motor->timerHardware->channel)], 4, packet);
        motor->timer->dmaBurstLength = bufferSize * 4;
    } else
#endif
    {
        bufferSize = loadDmaBuffer(motor->dmaBuffer, 1, packet);
        motor->timer->timerDmaSources |= motor->timerDmaSource;
        DMA_SetCurrDataCounter(motor->timerHardware->dmaRef, bufferSize);
        DMA_Cmd(motor->timerHardware->dmaRef, ENABLE);
    }
}

void pwmCompleteDshotMotorUpdate(uint8_t motorCount)
{
    UNUSED(motorCount);

    for (int i = 0; i < dmaMotorTimerCount; i++) {
#ifdef USE_DSHOT_DMAR
        if (useBurstDshot) {
            DMA_SetCurrDataCounter(dmaMotorTimers[i].dmaBurstRef, dmaMotorTimers[i].dmaBurstLength);
            DMA_Cmd(dmaMotorTimers[i].dmaBurstRef, ENABLE);
            TIM_DMAConfig(dmaMotorTimers[i].timer, TIM_DMABase_CCR1, TIM_DMABurstLength_4Transfers);
            TIM_DMACmd(dmaMotorTimers[i].timer, TIM_DMA_Update, ENABLE);
        } else
#endif
        {
            TIM_SetCounter(dmaMotorTimers[i].timer, 0);
            TIM_DMACmd(dmaMotorTimers[i].timer, dmaMotorTimers[i].timerDmaSources, ENABLE);
            dmaMotorTimers[i].timerDmaSources = 0;
        }
    }
}

static void motor_DMA_IRQHandler(dmaChannelDescriptor_t *descriptor)
{
    if (DMA_GET_FLAG_STATUS(descriptor, DMA_IT_TCIF)) {
        motorDmaOutput_t * const motor = &dmaMotors[descriptor->userParam];

#ifdef USE_DSHOT_DMAR
        if (useBurstDshot) {
            DMA_Cmd(motor->timerHardware->dmaTimUPRef, DISABLE);
            TIM_DMACmd(motor->timerHardware->tim, TIM_DMA_Update, DISABLE);
        } else
#endif
        {
            DMA_Cmd(motor->timerHardware->dmaRef, DISABLE);
            TIM_DMACmd(motor->timerHardware->tim, motor->timerDmaSource, DISABLE);
        }

        DMA_CLEAR_FLAG(descriptor, DMA_IT_TCIF);
    }
}

void pwmDshotMotorHardwareConfig(const timerHardware_t *timerHardware, uint8_t motorIndex, motorPwmProtocolTypes_e pwmProtocolType, uint8_t output)
{
#if defined(STM32F4) || defined(STM32F7)
    typedef DMA_Stream_TypeDef dmaStream_t;
#else
    typedef DMA_Channel_TypeDef dmaStream_t;
#endif

    dmaStream_t *dmaRef;

#ifdef USE_DSHOT_DMAR
    if (useBurstDshot) {
        dmaRef = timerHardware->dmaTimUPRef;
    } else
#endif
    {
        dmaRef = timerHardware->dmaRef;
    }

    if (dmaRef == NULL) {
        return;
    }

    TIM_OCInitTypeDef TIM_OCInitStructure;
    DMA_InitTypeDef DMA_InitStructure;

    motorDmaOutput_t * const motor = &dmaMotors[motorIndex];
    motor->timerHardware = timerHardware;

    TIM_TypeDef *timer = timerHardware->tim;
    const IO_t motorIO = IOGetByTag(timerHardware->tag);

    // Boolean configureTimer is always true when different channels of the same timer are processed in sequence,
    // causing the timer and the associated DMA initialized more than once.
    // To fix this, getTimerIndex must be expanded to return if a new timer has been requested.
    // However, since the initialization is idempotent, it is left as is in a favor of flash space (for now).
    const uint8_t timerIndex = getTimerIndex(timer);
    const bool configureTimer = (timerIndex == dmaMotorTimerCount-1);

    IOConfigGPIOAF(motorIO, IO_CONFIG(GPIO_Mode_AF, GPIO_Speed_50MHz, GPIO_OType_PP, GPIO_PuPd_UP), timerHardware->alternateFunction);

    if (configureTimer) {
        TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
        TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);

        RCC_ClockCmd(timerRCC(timer), ENABLE);
        TIM_Cmd(timer, DISABLE);

        TIM_TimeBaseStructure.TIM_Prescaler = (uint16_t)(lrintf((float) timerClock(timer) / getDshotHz(pwmProtocolType) + 0.01f) - 1);
        TIM_TimeBaseStructure.TIM_Period = pwmProtocolType == PWM_TYPE_PROSHOT1000 ? MOTOR_NIBBLE_LENGTH_PROSHOT : MOTOR_BITLENGTH;
        TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
        TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
        TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
        TIM_TimeBaseInit(timer, &TIM_TimeBaseStructure);
    }

    TIM_OCStructInit(&TIM_OCInitStructure);
    TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
    if (output & TIMER_OUTPUT_N_CHANNEL) {
        TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable;
        TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCNIdleState_Reset;
        TIM_OCInitStructure.TIM_OCNPolarity = (output & TIMER_OUTPUT_INVERTED) ? TIM_OCNPolarity_Low : TIM_OCNPolarity_High;
    } else {
        TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
        TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
        TIM_OCInitStructure.TIM_OCPolarity =  (output & TIMER_OUTPUT_INVERTED) ? TIM_OCPolarity_Low : TIM_OCPolarity_High;
    }
    TIM_OCInitStructure.TIM_Pulse = 0;

    timerOCInit(timer, timerHardware->channel, &TIM_OCInitStructure);
    timerOCPreloadConfig(timer, timerHardware->channel, TIM_OCPreload_Enable);

    if (output & TIMER_OUTPUT_N_CHANNEL) {
        TIM_CCxNCmd(timer, timerHardware->channel, TIM_CCxN_Enable);
    } else {
        TIM_CCxCmd(timer, timerHardware->channel, TIM_CCx_Enable);
    }

    if (configureTimer) {
        TIM_CtrlPWMOutputs(timer, ENABLE);
        TIM_ARRPreloadConfig(timer, ENABLE);
        TIM_Cmd(timer, ENABLE);
    }

    motor->timer = &dmaMotorTimers[timerIndex];

#ifdef USE_DSHOT_DMAR
    if (useBurstDshot) {
        motor->timer->dmaBurstRef = dmaRef;

        if (!configureTimer) {
            motor->configured = true;
            return;
        }
    } else
#endif
    {
        motor->timerDmaSource = timerDmaSource(timerHardware->channel);
        motor->timer->timerDmaSources &= ~motor->timerDmaSource;
    }

    DMA_Cmd(dmaRef, DISABLE);
    DMA_DeInit(dmaRef);
    DMA_StructInit(&DMA_InitStructure);

#ifdef USE_DSHOT_DMAR
    if (useBurstDshot) {
        dmaInit(timerHardware->dmaTimUPIrqHandler, OWNER_TIMUP, timerGetTIMNumber(timerHardware->tim));
        dmaSetHandler(timerHardware->dmaTimUPIrqHandler, motor_DMA_IRQHandler, NVIC_BUILD_PRIORITY(1, 2), motorIndex);

#if defined(STM32F3)
        DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)motor->timer->dmaBurstBuffer;
        DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
#else
        DMA_InitStructure.DMA_Channel = timerHardware->dmaTimUPChannel;
        DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)motor->timer->dmaBurstBuffer;
        DMA_InitStructure.DMA_DIR = DMA_DIR_MemoryToPeripheral;
        DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Enable;
        DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_Full;
        DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
        DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
#endif
        DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)&timerHardware->tim->DMAR;
        DMA_InitStructure.DMA_BufferSize = (pwmProtocolType == PWM_TYPE_PROSHOT1000) ? PROSHOT_DMA_BUFFER_SIZE : DSHOT_DMA_BUFFER_SIZE; // XXX
        DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
        DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
        DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Word;
        DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Word;
        DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
        DMA_InitStructure.DMA_Priority = DMA_Priority_High;
    } else
#endif
    {
        dmaInit(timerHardware->dmaIrqHandler, OWNER_MOTOR, RESOURCE_INDEX(motorIndex));
        dmaSetHandler(timerHardware->dmaIrqHandler, motor_DMA_IRQHandler, NVIC_BUILD_PRIORITY(1, 2), motorIndex);

#if defined(STM32F3)
        DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)motor->dmaBuffer;
        DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST;
        DMA_InitStructure.DMA_M2M = DMA_M2M_Disable;
#elif defined(STM32F4)
        DMA_InitStructure.DMA_Channel = timerHardware->dmaChannel;
        DMA_InitStructure.DMA_Memory0BaseAddr = (uint32_t)motor->dmaBuffer;
        DMA_InitStructure.DMA_DIR = DMA_DIR_MemoryToPeripheral;
        DMA_InitStructure.DMA_FIFOMode = DMA_FIFOMode_Enable;
        DMA_InitStructure.DMA_FIFOThreshold = DMA_FIFOThreshold_1QuarterFull;
        DMA_InitStructure.DMA_MemoryBurst = DMA_MemoryBurst_Single;
        DMA_InitStructure.DMA_PeripheralBurst = DMA_PeripheralBurst_Single;
#endif
        DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t)timerChCCR(timerHardware);
        DMA_InitStructure.DMA_BufferSize = pwmProtocolType == PWM_TYPE_PROSHOT1000 ? PROSHOT_DMA_BUFFER_SIZE : DSHOT_DMA_BUFFER_SIZE;
        DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
        DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable;
        DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Word;
        DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Word;
        DMA_InitStructure.DMA_Mode = DMA_Mode_Normal;
        DMA_InitStructure.DMA_Priority = DMA_Priority_High;
    }

    // XXX Consolidate common settings in the next refactor

    DMA_Init(dmaRef, &DMA_InitStructure);
    DMA_ITConfig(dmaRef, DMA_IT_TC, ENABLE);

    motor->configured = true;
}

#endif