InfiniTime/src/drivers/SpiMaster.cpp
2019-12-07 17:11:50 +01:00

89 lines
2.5 KiB
C++

#include <hal/nrf_gpio.h>
#include "SpiMaster.h"
using namespace Pinetime::Drivers;
bool SpiMaster::Init(const SpiMaster::SpiModule spi, const SpiMaster::Parameters &params) {
/* Configure GPIO pins used for pselsck, pselmosi, pselmiso and pselss for SPI0 */
nrf_gpio_cfg_output(params.pinSCK);
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_SPI0; break;
case SpiModule::SPI1: spiBaseAddress = NRF_SPI1; break;
default: return false;
}
/* Configure pins, frequency and mode */
spiBaseAddress->PSELSCK = params.pinSCK;
spiBaseAddress->PSELMOSI = params.pinMOSI;
spiBaseAddress->PSELMISO = params.pinMISO;
nrf_gpio_pin_set(pinCsn); /* disable Set slave select (inactive high) */
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;
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_READY = 0;
spiBaseAddress->ENABLE = (SPI_ENABLE_ENABLE_Enabled << SPI_ENABLE_ENABLE_Pos);
return true;
}
bool SpiMaster::Write(const uint8_t *data, size_t size) {
volatile uint32_t dummyread;
if(data == nullptr) return false;
/* enable slave (slave select active low) */
nrf_gpio_pin_clear(pinCsn);
spiBaseAddress->EVENTS_READY = 0;
spiBaseAddress->TXD = (uint32_t)*data++;
while(--size)
{
spiBaseAddress->TXD = (uint32_t)*data++;
/* Wait for the transaction complete or timeout (about 10ms - 20 ms) */
while (spiBaseAddress->EVENTS_READY == 0);
/* clear the event to be ready to receive next messages */
spiBaseAddress->EVENTS_READY = 0;
dummyread = spiBaseAddress->RXD;
}
/* Wait for the transaction complete or timeout (about 10ms - 20 ms) */
while (spiBaseAddress->EVENTS_READY == 0);
dummyread = spiBaseAddress->RXD;
/* disable slave (slave select active low) */
nrf_gpio_pin_set(pinCsn);
return true;
}