SPI.cpp

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#include <algorithm>
 
#include "SPI.h"
#include "semaphore.hpp"
#include "cppmain.h"
#include "math.h"
 
static bool operator==(const SPI_InitTypeDef& lhs, const SPI_InitTypeDef& rhs) {
    return memcmp(&lhs,&rhs,sizeof(SPI_InitTypeDef)) == 0;
}
 
 
 
SPIPort::SPIPort(SPI_HandleTypeDef &hspi,const std::vector<OutputPin>& csPins,uint32_t baseclk,bool allowReconfigure)
: hspi{hspi}{
    this->current_device = nullptr;
    this->allowReconfigure = allowReconfigure;
    this->csPins = csPins;
    this->freePins = csPins;
    this->baseclk = baseclk;
}
 
// ----------------------------------
//CS pins
bool SPIPort::reserveCsPin(OutputPin pin){
    auto it = std::find(freePins.begin(), freePins.end(), pin);
    if(it != freePins.end()){
        freePins.erase(it);
        return true;
    }
    // Pin not found or not free
    return false;
}
 
 
 
bool SPIPort::freeCsPin(OutputPin pin){
    // is in pins
    if(std::find(csPins.begin(),csPins.end(), pin) != csPins.end()){
        // is not in free pins
        if(std::find(freePins.begin(),freePins.end(), pin) == freePins.end()){
            freePins.push_back(pin);
            return true;
        }
    }
 
    // Pin not found
    return false;
}
 
bool SPIPort::isPinFree(OutputPin pin){
    return(std::find(freePins.begin(),freePins.end(), pin) != freePins.end());
}
 
std::vector<OutputPin>& SPIPort::getFreeCsPins(){
 
    return freePins;
}
 
 
std::vector<OutputPin>& SPIPort::getCsPins(){
    return csPins;
}
 
OutputPin* SPIPort::getCsPin(uint16_t idx){
    if(idx < csPins.size()){
        return &csPins[idx];
    }
    return nullptr;
}
 
void SPIPort::configurePort(SPI_InitTypeDef* config){
    if(config == nullptr || hspi.Init == *config){
        return; // No need to reconfigure
    }
    hspi.Init = *config;
    HAL_SPI_Init(&hspi);
}
 
SPI_HandleTypeDef* SPIPort::getPortHandle(){
    return &hspi;
}
 
// ----------------------------------
void SPIPort::transmit_DMA(const uint8_t* buf,uint16_t size,SPIDevice* device){
    device->beginSpiTransfer(this);
    current_device = device; // Will call back this device
    if(!takenExclusive && this->allowReconfigure){
        this->configurePort(&device->getSpiConfig()->peripheral);
    }
    HAL_SPI_Transmit_DMA(&this->hspi,const_cast<uint8_t*>(buf),size);
    // Request completes in tx complete callback
}

void SPIPort::transmitReceive_DMA(const uint8_t* txbuf,uint8_t* rxbuf,uint16_t size,SPIDevice* device){
    device->beginSpiTransfer(this);
    if(!takenExclusive && this->allowReconfigure){
        this->configurePort(&device->getSpiConfig()->peripheral);
    }
    current_device = device; // Will call back this device
    HAL_SPI_TransmitReceive_DMA(&this->hspi,const_cast<uint8_t*>(txbuf),rxbuf,size);
    // Request completes in rxtx complete callback
}

void SPIPort::receive_DMA(uint8_t* buf,uint16_t size,SPIDevice* device){
    device->beginSpiTransfer(this);
    if(!takenExclusive && this->allowReconfigure){
        this->configurePort(&device->getSpiConfig()->peripheral);
    }
    current_device = device;
    HAL_SPI_Receive_DMA(&this->hspi,buf,size);
    // Request completes in rx complete callback
}
 
 
void SPIPort::transmit_IT(const uint8_t* buf,uint16_t size,SPIDevice* device){
    device->beginSpiTransfer(this);
    current_device = device; // Will call back this device
    if(!takenExclusive && this->allowReconfigure){
        this->configurePort(&device->getSpiConfig()->peripheral);
    }
    HAL_SPI_Transmit_IT(&this->hspi,const_cast<uint8_t*>(buf),size);
    // Request completes in tx complete callback
}
 
void SPIPort::transmitReceive_IT(const uint8_t* txbuf,uint8_t* rxbuf,uint16_t size,SPIDevice* device){
    device->beginSpiTransfer(this);
    if(!takenExclusive && this->allowReconfigure){
        this->configurePort(&device->getSpiConfig()->peripheral);
    }
    current_device = device; // Will call back this device
    HAL_SPI_TransmitReceive_IT(&this->hspi,const_cast<uint8_t*>(txbuf),rxbuf,size);
    // Request completes in rxtx complete callback
}
 
void SPIPort::receive_IT(uint8_t* buf,uint16_t size,SPIDevice* device){
    device->beginSpiTransfer(this);
    if(!takenExclusive && this->allowReconfigure){
        this->configurePort(&device->getSpiConfig()->peripheral);
    }
    current_device = device;
    HAL_SPI_Receive_IT(&this->hspi,buf,size);
    // Request completes in rx complete callback
}
 
void SPIPort::transmit(const uint8_t* buf,uint16_t size,SPIDevice* device,uint16_t timeout){
    device->beginSpiTransfer(this);
    if(!takenExclusive && this->allowReconfigure){
        this->configurePort(&device->getSpiConfig()->peripheral);
    }
    HAL_SPI_Transmit(&this->hspi,const_cast<uint8_t*>(buf),size,timeout);
    device->endSpiTransfer(this);
}
 
void SPIPort::receive(uint8_t* buf,uint16_t size,SPIDevice* device,int16_t timeout){
    device->beginSpiTransfer(this);
    if(!takenExclusive && this->allowReconfigure){
        this->configurePort(&device->getSpiConfig()->peripheral);
    }
    HAL_SPI_Receive(&this->hspi,buf,size,timeout);
    device->endSpiTransfer(this);
}
 
void SPIPort::transmitReceive(const uint8_t* txbuf,uint8_t* rxbuf,uint16_t size,SPIDevice* device,uint16_t timeout){
    device->beginSpiTransfer(this);
    if(!takenExclusive && this->allowReconfigure){
        this->configurePort(&device->getSpiConfig()->peripheral);
    }
    HAL_SPI_TransmitReceive(&this->hspi,const_cast<uint8_t*>(txbuf),rxbuf,size,timeout);
    device->endSpiTransfer(this);
}
// --------------------------------
 
void SPIPort::takeSemaphore(){
    bool isIsr = inIsr();
 
    if(isIsr){
        BaseType_t taskWoken = 0;
        this->semaphore.TakeFromISR(&taskWoken);
        portYIELD_FROM_ISR(taskWoken);
    }else{
        this->semaphore.Take();
    }
    isTakenFlag = true;
}
 
void SPIPort::giveSemaphore(){
    bool isIsr = inIsr();
    isTakenFlag = false;
    if(isIsr){
        BaseType_t taskWoken = 0;
        this->semaphore.GiveFromISR(&taskWoken);
        portYIELD_FROM_ISR(taskWoken);
    }else{
        this->semaphore.Give();
    }
 
}
 
bool SPIPort::isTaken(){
    return isTakenFlag;
}
 
void SPIPort::takeExclusive(bool exclusive){
    takenExclusive = exclusive;
}
 
bool SPIPort::hasFreePins(){
    return !takenExclusive && this->getCsPins().size() > 0;
}

uint32_t SPIPort::getBaseClk(){
    return this->baseclk;
}
 
// interrupt callbacks
void SPIPort::SpiTxCplt(SPI_HandleTypeDef *hspi) {
    if (current_device == nullptr) {
        return;
    }
 
    if (hspi->Instance != this->hspi.Instance) {
        return;
    }
    current_device->endSpiTransfer(this);
    current_device->spiTxCompleted(this);
 
    current_device = nullptr;
 
}
void SPIPort::SpiRxCplt(SPI_HandleTypeDef *hspi) {
    if (current_device == nullptr) {
        return;
    }
 
    if (hspi->Instance != this->hspi.Instance) {
        return;
    }
    current_device->endSpiTransfer(this);
    current_device->spiRxCompleted(this);
 
    current_device = nullptr;
}
void SPIPort::SpiTxRxCplt(SPI_HandleTypeDef *hspi) {
    if (current_device == nullptr) {
        return;
    }
 
    if (hspi->Instance != this->hspi.Instance) {
        return;
    }
    current_device->endSpiTransfer(this);
    current_device->spiTxRxCompleted(this);
 
    current_device = nullptr;
}
 
void SPIPort::SpiError(SPI_HandleTypeDef *hspi) {
    if (current_device == nullptr) {
        return;
    }
 
    if (hspi->Instance != this->hspi.Instance) {
        return;
    }
    current_device->endSpiTransfer(this);
    current_device->spiRequestError(this);
 
    current_device = nullptr;
}

std::pair<uint32_t,float> SPIPort::getClosestPrescaler(float clock){
    std::vector<std::pair<uint32_t,float>> distances;
#if defined(SPI_BAUDRATEPRESCALER_2)
    distances.push_back({SPI_BAUDRATEPRESCALER_2,(baseclk/2.0)});
#endif
#if defined(SPI_BAUDRATEPRESCALER_4)
    distances.push_back({SPI_BAUDRATEPRESCALER_4,(baseclk/4.0)});
#endif
#if defined(SPI_BAUDRATEPRESCALER_8)
    distances.push_back({SPI_BAUDRATEPRESCALER_8,(baseclk/8.0)});
#endif
#if defined(SPI_BAUDRATEPRESCALER_16)
    distances.push_back({SPI_BAUDRATEPRESCALER_16,(baseclk/16.0)});
#endif
#if defined(SPI_BAUDRATEPRESCALER_32)
    distances.push_back({SPI_BAUDRATEPRESCALER_32,(baseclk/32.0)});
#endif
#if defined(SPI_BAUDRATEPRESCALER_64)
    distances.push_back({SPI_BAUDRATEPRESCALER_64,(baseclk/64.0)});
#endif
#if defined(SPI_BAUDRATEPRESCALER_128)
    distances.push_back({SPI_BAUDRATEPRESCALER_128,(baseclk/128.0)});
#endif
#if defined(SPI_BAUDRATEPRESCALER_256)
    distances.push_back({SPI_BAUDRATEPRESCALER_256,(baseclk/256.0)});
#endif
    // Calc distances
    std::pair<uint32_t,float> bestVal = distances[0];
    float bestDist = INFINITY;
    for(auto& val : distances){
        if(std::abs(clock-val.second) < bestDist){
            bestDist = abs(clock-val.second);
            bestVal = val;
        }
    }
    return bestVal;
}
 
SPIDevice::SPIDevice(SPIPort& port,SPIConfig& spiConfig) : spiPort{port},spiConfig{spiConfig}{
    spiPort.reserveCsPin(spiConfig.cs);
}
SPIDevice::SPIDevice(SPIPort& port,OutputPin csPin) : spiPort{port},spiConfig{csPin}{
    this->spiConfig.cs = csPin;
    spiPort.reserveCsPin(spiConfig.cs);
}
SPIDevice::~SPIDevice() {
    spiPort.freeCsPin(spiConfig.cs);
}
 
bool SPIDevice::updateCSPin(OutputPin& csPin){
    if(csPin == spiConfig.cs){
        return true;
    }
    if(!spiPort.isPinFree(csPin)){
        return false;
    }
 
    if(!spiPort.freeCsPin(spiConfig.cs)){
        return false;
    }
    spiConfig.cs = csPin;
    return spiPort.reserveCsPin(csPin);
}
 
/*
 * Called before the spi transfer starts.
 * Can be used to take the semaphore and set CS pins by default
 */
void SPIDevice::beginSpiTransfer(SPIPort* port){
    port->takeSemaphore();
    assertChipSelect();
}
 
/*
 * Called after a transfer is finished
 * Gives a semaphore back and resets the CS pin
 */
void SPIDevice::endSpiTransfer(SPIPort* port){
    clearChipSelect();
    port->giveSemaphore();
}
 
void SPIDevice::assertChipSelect() {
    spiConfig.cs.write(!spiConfig.cspol);
}
 
void SPIDevice::clearChipSelect() {
    spiConfig.cs.write(spiConfig.cspol);
}