I have a raspberry pi5 and this is the code of how I started the SPI communication of the RPI5 - TangNano9K. (Not yet machine tested)
OS:
In /boot/broadcom/config.txt check is SPI is enabled (reboot if not)
# uncomment some or all of these to enable the optional hardware interfaces
#dtparam=i2c_arm=on
#dtparam=i2s=on
dtparam=spi=on
In /dev/
Check do you have listed spidev0.0, should be!
In RIO.h define:
#define TRANSPORT_SPI5
In RIO C add lines:
#ifdef TRANSPORT_SPI5
#include <linux/spi/spidev.h>
#include <sys/ioctl.h>
#endif
/***********************************************************************
* STRUCTURES AND GLOBAL VARIABLES *
************************************************************************/
#ifdef TRANSPORT_SPI5
int spifd;
static uint8_t mode = SPI_MODE_0;
static uint8_t bits = 8;
static uint32_t speed = 1500000;
#endif
/***********************************************************************
* INIT AND EXIT CODE *
************************************************************************/
#ifdef TRANSPORT_SPI5
rtapi_print("Info: Initialize SPI5 connection\n");
spifd = open("/dev/spidev0.0", O_RDWR);
if (spifd < 0) {
rtapi_print_msg(RTAPI_MSG_ERR,"Failed to open SPI device\n");
return -1;
}
// Set SPI mode
if (ioctl(spifd, SPI_IOC_WR_MODE, &mode) == -1) {
rtapi_print_msg(RTAPI_MSG_ERR,"Failed to set SPI mode\n");
close(spifd);
return -1;
}
// Set bits per word
if (ioctl(spifd, SPI_IOC_WR_BITS_PER_WORD, &bits) == -1) {
rtapi_print_msg(RTAPI_MSG_ERR,"Failed to set bits per word\n");
close(spifd);
return -1;
}
// Set max speed
if (ioctl(spifd, SPI_IOC_WR_MAX_SPEED_HZ, &speed) == -1) {
rtapi_print_msg(RTAPI_MSG_ERR,"Failed to set max speed\n");
close(spifd);
return -1;
}
#endif
//Edit rtapi_app_exit function, add close(spifd)
void rtapi_app_exit(void)
{
close(spifd);
hal_exit(comp_id);
}
//In fuction void rio_transfer() near end of it add:
#ifdef TRANSPORT_SPI5
struct spi_ioc_transfer tr = {
//.tx_buf = (uint64_t)tx_buf,
//.rx_buf = (uint64_t)rx_buf,
.tx_buf = (uint64_t)txData.txBuffer,
.rx_buf = (uint64_t)rxData.rxBuffer,
.len = SPIBUFSIZE,
.speed_hz = speed,
.delay_usecs = 0,
.bits_per_word = bits,
};
// Perform SPI transfer
if (ioctl(spifd, SPI_IOC_MESSAGE(1), &tr) == -1) {
rtapi_print_msg(RTAPI_MSG_ERR,"Failed to perform SPI transfer\n");
//close(spifd);
//return -1;
}
#endif
//Save and do hallcompile...
