SPI: random data length/tx/rx for DMA SPI transfers (eg. size over 32 bytes) "CONFIG_SPI_ROCKCHIP" #19
Description
SPI driver CONFIG_SPI_ROCKCHIP (drivers/spi/spi-rockchip.c) does not work for transfers over 32 bytes (switched to DMA transfers, see rockchip_spi_can_dma()). Totally random length/rx/tx are send and received with rk3288 (TinkerBoard, TinkerOS 1.8). Checked with external protocol analyzer and testing code:
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <inttypes.h>
#include <linux/spi/spidev.h>
#include <linux/types.h>
#include <sys/ioctl.h>
#include <linux/ioctl.h>
// SZ <= 32 OK (PIO transfers), >32 radom length send, random data send (checked from logic analyzer), random data received (DMA transfers)
#define SZ 33
int main()
{
int fd = open("/dev/spidev2.0", O_RDWR);
uint8_t mode = SPI_MODE_3;
ioctl(fd, SPI_IOC_WR_MODE, &mode);
ioctl(fd, SPI_IOC_RD_MODE, &mode);
struct spi_ioc_transfer xfer;
memset(&xfer, 0, sizeof(xfer));
uint8_t tx_buf[SZ] = "\03\0\0\0"; // "\03\0\0\0" read from SPI flash or "\237" Manufacturer and Device ID Read (len 7)
uint8_t rx_buf[SZ];
xfer.tx_buf = (unsigned long)&tx_buf;
xfer.rx_buf = (unsigned long)&rx_buf;
xfer.len = sizeof(rx_buf);
xfer.speed_hz = 10000000;
xfer.bits_per_word = 8;
int status = ioctl(fd, SPI_IOC_MESSAGE(1), &xfer);
printf("status %d\n", status);
int i;
for(i=0; i<sizeof(rx_buf); i++) printf("%02x ", rx_buf[i]);
printf("\n");
close(fd);
return 0;
}