TwiMaster is now based on the NRFX TWI driver, as it handles more edge cases and workarounds for errors on the bus.

Reset the TWI bus after the soft-reset of the motion sensor to workaround issues on the TWI bus.

1 files changed, 40 insertions, 185 deletions

diff --git a/src/drivers/TwiMaster.cpp b/src/drivers/TwiMaster.cpp
index 6a063ec..646823d 100644
--- a/src/drivers/TwiMaster.cpp
+++ b/src/drivers/TwiMaster.cpp
@@ -2,195 +2,77 @@
 #include <cstring>
 #include <hal/nrf_gpio.h>
 #include <nrfx_log.h>
-
+#include <nrfx_twim.h>
+#include <nrf_drv_twi.h>
 using namespace Pinetime::Drivers;
 
 // TODO use shortcut to automatically send STOP when receive LastTX, for example
 // TODO use DMA/IRQ
 
-TwiMaster::TwiMaster(const Modules module, const Parameters& params) : module{module}, params{params} {
-  mutex = xSemaphoreCreateBinary();
-}
-
-void TwiMaster::Init() {
-  NRF_GPIO->PIN_CNF[params.pinScl] = ((uint32_t)GPIO_PIN_CNF_DIR_Input      << GPIO_PIN_CNF_DIR_Pos)
-                                     | ((uint32_t)GPIO_PIN_CNF_INPUT_Connect    << GPIO_PIN_CNF_INPUT_Pos)
-                                     | ((uint32_t)GPIO_PIN_CNF_PULL_Pullup      << GPIO_PIN_CNF_PULL_Pos)
-                                     | ((uint32_t)GPIO_PIN_CNF_DRIVE_S0D1       << GPIO_PIN_CNF_DRIVE_Pos)
-                                     | ((uint32_t)GPIO_PIN_CNF_SENSE_Disabled   << GPIO_PIN_CNF_SENSE_Pos);
-
-  NRF_GPIO->PIN_CNF[params.pinSda] = ((uint32_t)GPIO_PIN_CNF_DIR_Input        << GPIO_PIN_CNF_DIR_Pos)
-                                     | ((uint32_t)GPIO_PIN_CNF_INPUT_Connect    << GPIO_PIN_CNF_INPUT_Pos)
-                                     | ((uint32_t)GPIO_PIN_CNF_PULL_Pullup      << GPIO_PIN_CNF_PULL_Pos)
-                                     | ((uint32_t)GPIO_PIN_CNF_DRIVE_S0D1       << GPIO_PIN_CNF_DRIVE_Pos)
-                                     | ((uint32_t)GPIO_PIN_CNF_SENSE_Disabled   << GPIO_PIN_CNF_SENSE_Pos);
-
+TwiMaster::TwiMaster(const Modules module, const Parameters& params) : module{module}, params{params}, mutex{xSemaphoreCreateBinary()} {
+  ASSERT(mutex != nullptr);
   switch(module) {
-    case Modules::TWIM1: twiBaseAddress = NRF_TWIM1; break;
+    case Modules::TWIM1:
     default:
-      return;
-  }
-
-  switch(static_cast<Frequencies>(params.frequency)) {
-    case Frequencies::Khz100 : twiBaseAddress->FREQUENCY = TWIM_FREQUENCY_FREQUENCY_K100; break;
-    case Frequencies::Khz250 : twiBaseAddress->FREQUENCY = TWIM_FREQUENCY_FREQUENCY_K250; break;
-    case Frequencies::Khz400 : twiBaseAddress->FREQUENCY = TWIM_FREQUENCY_FREQUENCY_K400; break;
+      twim = NRFX_TWIM_INSTANCE(1);
+      break;
   }
+}
 
-  twiBaseAddress->PSEL.SCL = params.pinScl;
-  twiBaseAddress->PSEL.SDA = params.pinSda;
-  twiBaseAddress->EVENTS_LASTRX = 0;
-  twiBaseAddress->EVENTS_STOPPED = 0;
-  twiBaseAddress->EVENTS_LASTTX = 0;
-  twiBaseAddress->EVENTS_ERROR = 0;
-  twiBaseAddress->EVENTS_RXSTARTED = 0;
-  twiBaseAddress->EVENTS_SUSPENDED = 0;
-  twiBaseAddress->EVENTS_TXSTARTED = 0;
-
-  twiBaseAddress->ENABLE = (TWIM_ENABLE_ENABLE_Enabled << TWIM_ENABLE_ENABLE_Pos);
-
-
-  /* // IRQ
-     NVIC_ClearPendingIRQ(_IRQn);
-     NVIC_SetPriority(_IRQn, 2);
-     NVIC_EnableIRQ(_IRQn);
-   */
+void TwiMaster::Init() {
+  nrfx_twim_config_t config;
+  config.frequency = static_cast<nrf_twim_frequency_t>(params.frequency);
+  config.hold_bus_uninit = false;
+  config.interrupt_priority = 0;
+  config.scl = params.pinScl;
+  config.sda = params.pinSda;
+  nrfx_twim_init(&twim,
+                 &config,
+                 nullptr,
+                 nullptr);
+  nrfx_twim_enable(&twim);
 
   xSemaphoreGive(mutex);
-
 }
 
 TwiMaster::ErrorCodes TwiMaster::Read(uint8_t deviceAddress, uint8_t registerAddress, uint8_t *data, size_t size) {
   xSemaphoreTake(mutex, portMAX_DELAY);
-  auto ret = ReadWithRetry(deviceAddress, registerAddress, data, size);
+  TwiMaster::ErrorCodes ret;
+
+  auto err = nrfx_twim_tx(&twim, deviceAddress, &registerAddress, 1, false);
+  if(err != 0) {
+    return TwiMaster::ErrorCodes::TransactionFailed;
+  }
+
+  err = nrfx_twim_rx(&twim, deviceAddress, data, size);
+  if(err != 0) {
+    return TwiMaster::ErrorCodes::TransactionFailed;
+  }
   xSemaphoreGive(mutex);
 
-  return ret;
+  return TwiMaster::ErrorCodes::NoError;
 }
 
 TwiMaster::ErrorCodes TwiMaster::Write(uint8_t deviceAddress, uint8_t registerAddress, const uint8_t *data, size_t size) {
   ASSERT(size <= maxDataSize);
   xSemaphoreTake(mutex, portMAX_DELAY);
-
-  auto ret = WriteWithRetry(deviceAddress, registerAddress, data, size);
-  xSemaphoreGive(mutex);
-  return ret;
-}
-
-/* Execute a read transaction (composed of a write and a read operation). If one of these opeartion fails,
- * it's retried once. If it fails again, an error is returned */
-TwiMaster::ErrorCodes TwiMaster::ReadWithRetry(uint8_t deviceAddress, uint8_t registerAddress, uint8_t *data, size_t size) {
   TwiMaster::ErrorCodes ret;
-  ret = Write(deviceAddress, &registerAddress, 1, false);
-  if(ret != ErrorCodes::NoError)
-    ret = Write(deviceAddress, &registerAddress, 1, false);
-
-  if(ret != ErrorCodes::NoError) return ret;
 
-  ret = Read(deviceAddress, data, size, true);
-  if(ret != ErrorCodes::NoError)
-    ret = Read(deviceAddress, data, size, true);
-
-  return ret;
-}
-
-/* Execute a write transaction. If it fails, it is retried once. If it fails again, an error is returned. */
-TwiMaster::ErrorCodes TwiMaster::WriteWithRetry(uint8_t deviceAddress, uint8_t registerAddress, const uint8_t *data, size_t size) {
   internalBuffer[0] = registerAddress;
   std::memcpy(internalBuffer+1, data, size);
-  auto ret = Write(deviceAddress, internalBuffer, size+1, true);
-  if(ret != ErrorCodes::NoError)
-    ret = Write(deviceAddress, internalBuffer, size+1, true);
-
-  return ret;
-}
-
-
-TwiMaster::ErrorCodes TwiMaster::Read(uint8_t deviceAddress, uint8_t *buffer, size_t size, bool stop) {
-  twiBaseAddress->ADDRESS = deviceAddress;
-  twiBaseAddress->TASKS_RESUME = 0x1UL;
-  twiBaseAddress->RXD.PTR = (uint32_t)buffer;
-  twiBaseAddress->RXD.MAXCNT = size;
-
-  twiBaseAddress->TASKS_STARTRX = 1;
-
-  while(!twiBaseAddress->EVENTS_RXSTARTED && !twiBaseAddress->EVENTS_ERROR);
-  twiBaseAddress->EVENTS_RXSTARTED = 0x0UL;
-
-  txStartedCycleCount = DWT->CYCCNT;
-  uint32_t currentCycleCount;
-  while(!twiBaseAddress->EVENTS_LASTRX && !twiBaseAddress->EVENTS_ERROR) {
-    currentCycleCount = DWT->CYCCNT;
-    if ((currentCycleCount-txStartedCycleCount) > HwFreezedDelay) {
-      FixHwFreezed();
-      return ErrorCodes::TransactionFailed;
-    }
-  }
-  twiBaseAddress->EVENTS_LASTRX = 0x0UL;
-
-  if (stop || twiBaseAddress->EVENTS_ERROR) {
-    twiBaseAddress->TASKS_STOP = 0x1UL;
-    while(!twiBaseAddress->EVENTS_STOPPED);
-    twiBaseAddress->EVENTS_STOPPED = 0x0UL;
-  }
-  else {
-    twiBaseAddress->TASKS_SUSPEND = 0x1UL;
-    while(!twiBaseAddress->EVENTS_SUSPENDED);
-    twiBaseAddress->EVENTS_SUSPENDED = 0x0UL;
+  auto err = nrfx_twim_tx(&twim, deviceAddress, internalBuffer , size+1, false);
+  if(err != 0){
+    return TwiMaster::ErrorCodes::TransactionFailed;
   }
 
-  if (twiBaseAddress->EVENTS_ERROR) {
-    twiBaseAddress->EVENTS_ERROR = 0x0UL;
-  }
-  return ErrorCodes::NoError;
-}
-
-TwiMaster::ErrorCodes TwiMaster::Write(uint8_t deviceAddress, const uint8_t *data, size_t size, bool stop) {
-  twiBaseAddress->ADDRESS = deviceAddress;
-  twiBaseAddress->TASKS_RESUME = 0x1UL;
-  twiBaseAddress->TXD.PTR = (uint32_t)data;
-  twiBaseAddress->TXD.MAXCNT = size;
-
-  twiBaseAddress->TASKS_STARTTX = 1;
-
-  while(!twiBaseAddress->EVENTS_TXSTARTED && !twiBaseAddress->EVENTS_ERROR);
-  twiBaseAddress->EVENTS_TXSTARTED = 0x0UL;
-
-  txStartedCycleCount = DWT->CYCCNT;
-  uint32_t currentCycleCount;
-  while(!twiBaseAddress->EVENTS_LASTTX && !twiBaseAddress->EVENTS_ERROR) {
-    currentCycleCount = DWT->CYCCNT;
-    if ((currentCycleCount-txStartedCycleCount) > HwFreezedDelay) {
-      FixHwFreezed();
-      return ErrorCodes::TransactionFailed;
-    }
-  }
-  twiBaseAddress->EVENTS_LASTTX = 0x0UL;
-
-  if (stop || twiBaseAddress->EVENTS_ERROR) {
-    twiBaseAddress->TASKS_STOP = 0x1UL;
-    while(!twiBaseAddress->EVENTS_STOPPED);
-    twiBaseAddress->EVENTS_STOPPED = 0x0UL;
-  }
-  else {
-    twiBaseAddress->TASKS_SUSPEND = 0x1UL;
-    while(!twiBaseAddress->EVENTS_SUSPENDED);
-    twiBaseAddress->EVENTS_SUSPENDED = 0x0UL;
-  }
-
-  if (twiBaseAddress->EVENTS_ERROR) {
-    twiBaseAddress->EVENTS_ERROR = 0x0UL;
-    uint32_t error = twiBaseAddress->ERRORSRC;
-    twiBaseAddress->ERRORSRC = error;
-  }
-
-  return ErrorCodes::NoError;
+  xSemaphoreGive(mutex);
+  return TwiMaster::ErrorCodes::NoError;
 }
 
 void TwiMaster::Sleep() {
-  while(twiBaseAddress->ENABLE != 0) {
-    twiBaseAddress->ENABLE = (TWIM_ENABLE_ENABLE_Disabled << TWIM_ENABLE_ENABLE_Pos);
-  }
+  nrfx_twim_disable(&twim);
+  nrfx_twim_uninit(&twim);
+
   nrf_gpio_cfg_default(6);
   nrf_gpio_cfg_default(7);
   NRF_LOG_INFO("[TWIMASTER] Sleep");
@@ -200,30 +82,3 @@ void TwiMaster::Wakeup() {
   Init();
   NRF_LOG_INFO("[TWIMASTER] Wakeup");
 }
-
-/* Sometimes, the TWIM device just freeze and never set the event EVENTS_LASTTX.
- * This method disable and re-enable the peripheral so that it works again.
- * This is just a workaround, and it would be better if we could find a way to prevent
- * this issue from happening.
- * */
-void TwiMaster::FixHwFreezed() {
-  NRF_LOG_INFO("I2C device frozen, reinitializing it!");
-  // Disable I²C
-  uint32_t twi_state = NRF_TWI1->ENABLE;
-  twiBaseAddress->ENABLE = TWIM_ENABLE_ENABLE_Disabled << TWI_ENABLE_ENABLE_Pos;
-
-  NRF_GPIO->PIN_CNF[params.pinScl] = ((uint32_t)GPIO_PIN_CNF_DIR_Input      << GPIO_PIN_CNF_DIR_Pos)
-                         | ((uint32_t)GPIO_PIN_CNF_INPUT_Connect    << GPIO_PIN_CNF_INPUT_Pos)
-                         | ((uint32_t)GPIO_PIN_CNF_PULL_Pullup      << GPIO_PIN_CNF_PULL_Pos)
-                         | ((uint32_t)GPIO_PIN_CNF_DRIVE_S0S1       << GPIO_PIN_CNF_DRIVE_Pos)
-                         | ((uint32_t)GPIO_PIN_CNF_SENSE_Disabled   << GPIO_PIN_CNF_SENSE_Pos);
-
-  NRF_GPIO->PIN_CNF[params.pinSda] = ((uint32_t)GPIO_PIN_CNF_DIR_Input        << GPIO_PIN_CNF_DIR_Pos)
-                         | ((uint32_t)GPIO_PIN_CNF_INPUT_Connect    << GPIO_PIN_CNF_INPUT_Pos)
-                         | ((uint32_t)GPIO_PIN_CNF_PULL_Pullup      << GPIO_PIN_CNF_PULL_Pos)
-                         | ((uint32_t)GPIO_PIN_CNF_DRIVE_S0S1       << GPIO_PIN_CNF_DRIVE_Pos)
-                         | ((uint32_t)GPIO_PIN_CNF_SENSE_Disabled   << GPIO_PIN_CNF_SENSE_Pos);
-
-  // Re-enable I²C
-  twiBaseAddress->ENABLE = twi_state;
-}