ardupilot/libraries/AP_HAL_AVR/SPIDevice_SPI0.cpp

100 lines
2.3 KiB
C++

#include <AP_HAL.h>
#if (CONFIG_HAL_BOARD == HAL_BOARD_APM1 || CONFIG_HAL_BOARD == HAL_BOARD_APM2)
#include <avr/io.h>
#include <AP_HAL.h>
#include "SPIDevices.h"
#include "GPIO.h"
#include "Semaphore.h"
#include "pins_arduino_mega.h"
using namespace AP_HAL_AVR;
extern const AP_HAL::HAL& hal;
#define SPI0_MISO_PIN 50
#define SPI0_MOSI_PIN 51
#define SPI0_SCK_PIN 52
AVRSemaphore AVRSPI0DeviceDriver::_semaphore;
static volatile bool spi0_transferflag = false;
void AVRSPI0DeviceDriver::init() {
hal.gpio->pinMode(SPI0_MISO_PIN, GPIO_INPUT);
hal.gpio->pinMode(SPI0_MOSI_PIN, GPIO_OUTPUT);
hal.gpio->pinMode(SPI0_SCK_PIN, GPIO_OUTPUT);
_cs_pin->mode(GPIO_OUTPUT);
_cs_pin->write(1);
/* Enable the SPI0 peripheral as a master */
SPCR = _BV(SPE) | _BV(MSTR);
}
AP_HAL::Semaphore* AVRSPI0DeviceDriver::get_semaphore() {
return &_semaphore;
}
inline void AVRSPI0DeviceDriver::_cs_assert() {
const uint8_t valid_spcr_mask =
(_BV(CPOL) | _BV(CPHA) | _BV(SPR1) | _BV(SPR0));
uint8_t new_spcr = SPCR | (_spcr & valid_spcr_mask);
SPCR = new_spcr;
const uint8_t valid_spsr_mask = _BV(SPI2X);
uint8_t new_spsr = SPSR | (_spsr & valid_spsr_mask);
SPSR = new_spsr;
_cs_pin->write(0);
}
inline void AVRSPI0DeviceDriver::_cs_release() {
_cs_pin->write(1);
}
inline uint8_t AVRSPI0DeviceDriver::_transfer(uint8_t data) {
if (spi0_transferflag) {
hal.scheduler->panic(PSTR("PANIC: SPI0 transfer collision"));
}
spi0_transferflag = true;
SPDR = data;
if (SPSR & _BV(WCOL)) {
hal.scheduler->panic(PSTR("PANIC: SPI0 write collision"));
return 0;
}
while(!(SPSR & _BV(SPIF)));
uint8_t read_spdr = SPDR;
spi0_transferflag = false;
return read_spdr;
}
void AVRSPI0DeviceDriver::transaction(const uint8_t *tx, uint8_t *rx,
uint16_t len) {
_cs_assert();
if (rx == NULL) {
for (uint16_t i = 0; i < len; i++) {
_transfer(tx[i]);
}
} else {
for (uint16_t i = 0; i < len; i++) {
rx[i] = _transfer(tx[i]);
}
}
_cs_release();
}
void AVRSPI0DeviceDriver::cs_assert() {
_cs_assert();
}
void AVRSPI0DeviceDriver::cs_release() {
_cs_release();
}
uint8_t AVRSPI0DeviceDriver::transfer(uint8_t data) {
return _transfer(data);
}
#endif