AM5728: spidev_test questions

looks like there is no support for loopback in the lopts struct even though the usage says there is. Sooo, how are you guys testing loopback. Do you not have a device attached to the spi bus?

static void print_usage(const char *prog)
{
printf("Usage: %s [-DsbdlHOLC3vpNR24SI]\n", prog);
puts(" -D --device device to use (default /dev/spidev1.1)\n"
" -s --speed max speed (Hz)\n"
" -d --delay delay (usec)\n"
" -b --bpw bits per word\n"
" -i --input input data from a file (e.g. \"test.bin\")\n"
" -o --output output data to a file (e.g. \"results.bin\")\n"
" -l --loop loopback\n"
" -H --cpha clock phase\n"
" -O --cpol clock polarity\n"
" -L --lsb least significant bit first\n"
" -C --cs-high chip select active high\n"
" -3 --3wire SI/SO signals shared\n"
" -v --verbose Verbose (show tx buffer)\n"
" -p Send data (e.g. \"1234\\xde\\xad\")\n"
" -N --no-cs no chip select\n"
" -R --ready slave pulls low to pause\n"
" -2 --dual dual transfer\n"
" -4 --quad quad transfer\n"
" -S --size transfer size\n"
" -I --iter iterations\n");
exit(1);
}

while (1) {
static const struct option lopts[] = {
{ "device", 1, 0, 'D' },
{ "speed", 1, 0, 's' },
{ "delay", 1, 0, 'd' },
{ "bpw", 1, 0, 'b' },
{ "input", 1, 0, 'i' },
{ "output", 1, 0, 'o' },
{ "loop", 0, 0, 'l' },
{ "cpha", 0, 0, 'H' },
{ "cpol", 0, 0, 'O' },
{ "lsb", 0, 0, 'L' },
{ "cs-high", 0, 0, 'C' },
{ "3wire", 0, 0, '3' },
{ "no-cs", 0, 0, 'N' },
{ "ready", 0, 0, 'R' },
{ "dual", 0, 0, '2' },
{ "verbose", 0, 0, 'v' },
{ "quad", 0, 0, '4' },
{ "size", 1, 0, 'S' },
{ "iter", 1, 0, 'I' },
{ NULL, 0, 0, 0 },