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#include "drivers/TwiMaster.h"
#include <cstring>
#include <hal/nrf_gpio.h>
#include <nrfx_log.h>
using namespace Pinetime::Drivers;
// TODO use shortcut to automatically send STOP when receive LastTX, for example
// TODO use DMA/IRQ
TwiMaster::TwiMaster(NRF_TWIM_Type* module, uint32_t frequency, uint8_t pinSda, uint8_t pinScl)
: module {module}, frequency {frequency}, pinSda {pinSda}, pinScl {pinScl} {
}
void TwiMaster::ConfigurePins() const {
NRF_GPIO->PIN_CNF[pinScl] = (GPIO_PIN_CNF_DIR_Input << GPIO_PIN_CNF_DIR_Pos) | (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos) |
(GPIO_PIN_CNF_PULL_Disabled << GPIO_PIN_CNF_PULL_Pos) | (GPIO_PIN_CNF_DRIVE_S0D1 << GPIO_PIN_CNF_DRIVE_Pos) |
(GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos);
NRF_GPIO->PIN_CNF[pinSda] = (GPIO_PIN_CNF_DIR_Input << GPIO_PIN_CNF_DIR_Pos) | (GPIO_PIN_CNF_INPUT_Connect << GPIO_PIN_CNF_INPUT_Pos) |
(GPIO_PIN_CNF_PULL_Disabled << GPIO_PIN_CNF_PULL_Pos) | (GPIO_PIN_CNF_DRIVE_S0D1 << GPIO_PIN_CNF_DRIVE_Pos) |
(GPIO_PIN_CNF_SENSE_Disabled << GPIO_PIN_CNF_SENSE_Pos);
}
void TwiMaster::Init() {
if (mutex == nullptr) {
mutex = xSemaphoreCreateBinary();
}
ConfigurePins();
twiBaseAddress = module;
twiBaseAddress->FREQUENCY = frequency;
twiBaseAddress->PSEL.SCL = pinScl;
twiBaseAddress->PSEL.SDA = 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);
xSemaphoreGive(mutex);
}
TwiMaster::ErrorCodes TwiMaster::Read(uint8_t deviceAddress, uint8_t registerAddress, uint8_t* data, size_t size) {
xSemaphoreTake(mutex, portMAX_DELAY);
Wakeup();
auto ret = Write(deviceAddress, ®isterAddress, 1, false);
ret = Read(deviceAddress, data, size, true);
Sleep();
xSemaphoreGive(mutex);
return ret;
}
TwiMaster::ErrorCodes TwiMaster::Write(uint8_t deviceAddress, uint8_t registerAddress, const uint8_t* data, size_t size) {
ASSERT(size <= maxDataSize);
xSemaphoreTake(mutex, portMAX_DELAY);
Wakeup();
internalBuffer[0] = registerAddress;
std::memcpy(internalBuffer + 1, data, size);
auto ret = Write(deviceAddress, internalBuffer, size + 1, true);
Sleep();
xSemaphoreGive(mutex);
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;
}
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;
}
void TwiMaster::Sleep() {
twiBaseAddress->ENABLE = (TWIM_ENABLE_ENABLE_Disabled << TWIM_ENABLE_ENABLE_Pos);
}
void TwiMaster::Wakeup() {
twiBaseAddress->ENABLE = (TWIM_ENABLE_ENABLE_Enabled << TWIM_ENABLE_ENABLE_Pos);
}
/* 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!");
uint32_t twi_state = NRF_TWI1->ENABLE;
Sleep();
twiBaseAddress->ENABLE = twi_state;
}
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