InfiniTime/src/drivers/SpiMaster.cpp

#include "SpiMaster.h"
#include <hal/nrf_gpio.h>
#include <hal/nrf_spim.h>
#include <nrfx_log.h>
#include <algorithm>

using namespace Pinetime::Drivers;

SpiMaster::SpiMaster(const SpiMaster::SpiModule spi, const SpiMaster::Parameters& params) : spi {spi}, params {params} {
}

bool SpiMaster::Init() {
  if(mutex == nullptr) {
    mutex = xSemaphoreCreateBinary();
    ASSERT(mutex != nullptr);
  }

  /* Configure GPIO pins used for pselsck, pselmosi, pselmiso and pselss for SPI0 */
  nrf_gpio_pin_set(params.pinSCK);
  nrf_gpio_cfg_output(params.pinSCK);
  nrf_gpio_pin_clear(params.pinMOSI);
  nrf_gpio_cfg_output(params.pinMOSI);
  nrf_gpio_cfg_input(params.pinMISO, NRF_GPIO_PIN_NOPULL);
  //  nrf_gpio_cfg_output(params.pinCSN);
  //  pinCsn = params.pinCSN;

  switch (spi) {
    case SpiModule::SPI0:
      spiBaseAddress = NRF_SPIM0;
      break;
    case SpiModule::SPI1:
      spiBaseAddress = NRF_SPIM1;
      break;
    default:
      return false;
  }

  /* Configure pins, frequency and mode */
  spiBaseAddress->PSELSCK = params.pinSCK;
  spiBaseAddress->PSELMOSI = params.pinMOSI;
  spiBaseAddress->PSELMISO = params.pinMISO;

  uint32_t frequency;
  switch (params.Frequency) {
    case Frequencies::Freq8Mhz:
      frequency = 0x80000000;
      break;
    default:
      return false;
  }
  spiBaseAddress->FREQUENCY = frequency;

  uint32_t regConfig = 0;
  switch (params.bitOrder) {
    case BitOrder::Msb_Lsb:
      break;
    case BitOrder::Lsb_Msb:
      regConfig = 1;
      break;
    default:
      return false;
  }
  switch (params.mode) {
    case Modes::Mode0:
      break;
    case Modes::Mode1:
      regConfig |= (0x01 << 1);
      break;
    case Modes::Mode2:
      regConfig |= (0x02 << 1);
      break;
    case Modes::Mode3:
      regConfig |= (0x03 << 1);
      break;
    default:
      return false;
  }

  spiBaseAddress->CONFIG = regConfig;
  spiBaseAddress->EVENTS_ENDRX = 0;
  spiBaseAddress->EVENTS_ENDTX = 0;
  spiBaseAddress->EVENTS_END = 0;

  spiBaseAddress->INTENSET = ((unsigned) 1 << (unsigned) 6);
  spiBaseAddress->INTENSET = ((unsigned) 1 << (unsigned) 1);
  spiBaseAddress->INTENSET = ((unsigned) 1 << (unsigned) 19);

  spiBaseAddress->ENABLE = (SPIM_ENABLE_ENABLE_Enabled << SPIM_ENABLE_ENABLE_Pos);

  NRFX_IRQ_PRIORITY_SET(SPIM0_SPIS0_TWIM0_TWIS0_SPI0_TWI0_IRQn, 2);
  NRFX_IRQ_ENABLE(SPIM0_SPIS0_TWIM0_TWIS0_SPI0_TWI0_IRQn);

  xSemaphoreGive(mutex);
  return true;
}

void SpiMaster::SetupWorkaroundForFtpan58(NRF_SPIM_Type* spim, uint32_t ppi_channel, uint32_t gpiote_channel) {
  // Create an event when SCK toggles.
  NRF_GPIOTE->CONFIG[gpiote_channel] = (GPIOTE_CONFIG_MODE_Event << GPIOTE_CONFIG_MODE_Pos) | (spim->PSEL.SCK << GPIOTE_CONFIG_PSEL_Pos) |
                                       (GPIOTE_CONFIG_POLARITY_Toggle << GPIOTE_CONFIG_POLARITY_Pos);

  // Stop the spim instance when SCK toggles.
  NRF_PPI->CH[ppi_channel].EEP = (uint32_t) &NRF_GPIOTE->EVENTS_IN[gpiote_channel];
  NRF_PPI->CH[ppi_channel].TEP = (uint32_t) &spim->TASKS_STOP;
  NRF_PPI->CHENSET = 1U << ppi_channel;
  spiBaseAddress->EVENTS_END = 0;

  // Disable IRQ
  spim->INTENCLR = (1 << 6);
  spim->INTENCLR = (1 << 1);
  spim->INTENCLR = (1 << 19);
}

void SpiMaster::DisableWorkaroundForFtpan58(NRF_SPIM_Type* spim, uint32_t ppi_channel, uint32_t gpiote_channel) {
  NRF_GPIOTE->CONFIG[gpiote_channel] = 0;
  NRF_PPI->CH[ppi_channel].EEP = 0;
  NRF_PPI->CH[ppi_channel].TEP = 0;
  NRF_PPI->CHENSET = ppi_channel;
  spiBaseAddress->EVENTS_END = 0;
  spim->INTENSET = (1 << 6);
  spim->INTENSET = (1 << 1);
  spim->INTENSET = (1 << 19);
}

void SpiMaster::OnEndEvent() {
  if (currentBufferAddr == 0) {
    return;
  }

  auto s = currentBufferSize;
  if (s > 0) {
    auto currentSize = std::min((size_t) 255, s);
    PrepareTx(currentBufferAddr, currentSize);
    currentBufferAddr += currentSize;
    currentBufferSize -= currentSize;

    spiBaseAddress->TASKS_START = 1;
  } else {
    BaseType_t xHigherPriorityTaskWoken = pdFALSE;
    if (taskToNotify != nullptr) {
      vTaskNotifyGiveFromISR(taskToNotify, &xHigherPriorityTaskWoken);
      portYIELD_FROM_ISR(xHigherPriorityTaskWoken);
    }

    nrf_gpio_pin_set(this->pinCsn);
    currentBufferAddr = 0;
    BaseType_t xHigherPriorityTaskWoken2 = pdFALSE;
    xSemaphoreGiveFromISR(mutex, &xHigherPriorityTaskWoken2);
    portYIELD_FROM_ISR(xHigherPriorityTaskWoken | xHigherPriorityTaskWoken2);
  }
}

void SpiMaster::OnStartedEvent() {
}

void SpiMaster::PrepareTx(const volatile uint32_t bufferAddress, const volatile size_t size) {
  spiBaseAddress->TXD.PTR = bufferAddress;
  spiBaseAddress->TXD.MAXCNT = size;
  spiBaseAddress->TXD.LIST = 0;
  spiBaseAddress->RXD.PTR = 0;
  spiBaseAddress->RXD.MAXCNT = 0;
  spiBaseAddress->RXD.LIST = 0;
  spiBaseAddress->EVENTS_END = 0;
}

void SpiMaster::PrepareRx(const volatile uint32_t cmdAddress,
                          const volatile size_t cmdSize,
                          const volatile uint32_t bufferAddress,
                          const volatile size_t size) {
  spiBaseAddress->TXD.PTR = 0;
  spiBaseAddress->TXD.MAXCNT = 0;
  spiBaseAddress->TXD.LIST = 0;
  spiBaseAddress->RXD.PTR = bufferAddress;
  spiBaseAddress->RXD.MAXCNT = size;
  spiBaseAddress->RXD.LIST = 0;
  spiBaseAddress->EVENTS_END = 0;
}

bool SpiMaster::Write(uint8_t pinCsn, const uint8_t* data, size_t size) {
  if (data == nullptr)
    return false;
  auto ok = xSemaphoreTake(mutex, portMAX_DELAY);
  ASSERT(ok == true);
  taskToNotify = xTaskGetCurrentTaskHandle();

  this->pinCsn = pinCsn;

  if (size == 1) {
    SetupWorkaroundForFtpan58(spiBaseAddress, 0, 0);
  } else {
    DisableWorkaroundForFtpan58(spiBaseAddress, 0, 0);
  }

  nrf_gpio_pin_clear(this->pinCsn);

  currentBufferAddr = (uint32_t) data;
  currentBufferSize = size;

  auto currentSize = std::min((size_t) 255, (size_t) currentBufferSize);
  PrepareTx(currentBufferAddr, currentSize);
  currentBufferSize -= currentSize;
  currentBufferAddr += currentSize;
  spiBaseAddress->TASKS_START = 1;

  if (size == 1) {
    while (spiBaseAddress->EVENTS_END == 0)
      ;
    nrf_gpio_pin_set(this->pinCsn);
    currentBufferAddr = 0;
    xSemaphoreGive(mutex);
  }

  return true;
}

bool SpiMaster::Read(uint8_t pinCsn, uint8_t* cmd, size_t cmdSize, uint8_t* data, size_t dataSize) {
  xSemaphoreTake(mutex, portMAX_DELAY);

  taskToNotify = nullptr;

  this->pinCsn = pinCsn;
  DisableWorkaroundForFtpan58(spiBaseAddress, 0, 0);
  spiBaseAddress->INTENCLR = (1 << 6);
  spiBaseAddress->INTENCLR = (1 << 1);
  spiBaseAddress->INTENCLR = (1 << 19);

  nrf_gpio_pin_clear(this->pinCsn);

  currentBufferAddr = 0;
  currentBufferSize = 0;

  PrepareTx((uint32_t) cmd, cmdSize);
  spiBaseAddress->TASKS_START = 1;
  while (spiBaseAddress->EVENTS_END == 0)
    ;

  PrepareRx((uint32_t) cmd, cmdSize, (uint32_t) data, dataSize);
  spiBaseAddress->TASKS_START = 1;

  while (spiBaseAddress->EVENTS_END == 0)
    ;
  nrf_gpio_pin_set(this->pinCsn);

  xSemaphoreGive(mutex);

  return true;
}

void SpiMaster::Sleep() {
  while (spiBaseAddress->ENABLE != 0) {
    spiBaseAddress->ENABLE = (SPIM_ENABLE_ENABLE_Disabled << SPIM_ENABLE_ENABLE_Pos);
  }
  nrf_gpio_cfg_default(params.pinSCK);
  nrf_gpio_cfg_default(params.pinMOSI);
  nrf_gpio_cfg_default(params.pinMISO);

  NRF_LOG_INFO("[SPIMASTER] sleep")
}

void SpiMaster::Wakeup() {
  Init();
  NRF_LOG_INFO("[SPIMASTER] Wakeup");
}

bool SpiMaster::WriteCmdAndBuffer(uint8_t pinCsn, const uint8_t* cmd, size_t cmdSize, const uint8_t* data, size_t dataSize) {
  xSemaphoreTake(mutex, portMAX_DELAY);

  taskToNotify = nullptr;

  this->pinCsn = pinCsn;
  DisableWorkaroundForFtpan58(spiBaseAddress, 0, 0);
  spiBaseAddress->INTENCLR = (1 << 6);
  spiBaseAddress->INTENCLR = (1 << 1);
  spiBaseAddress->INTENCLR = (1 << 19);

  nrf_gpio_pin_clear(this->pinCsn);

  currentBufferAddr = 0;
  currentBufferSize = 0;

  PrepareTx((uint32_t) cmd, cmdSize);
  spiBaseAddress->TASKS_START = 1;
  while (spiBaseAddress->EVENTS_END == 0)
    ;

  PrepareTx((uint32_t) data, dataSize);
  spiBaseAddress->TASKS_START = 1;

  while (spiBaseAddress->EVENTS_END == 0)
    ;
  nrf_gpio_pin_set(this->pinCsn);

  xSemaphoreGive(mutex);

  return true;
}