Is anyone actively using spi_sam0 driver in your applications? I tried enabling it on SAMD21_xpro but I am unable to see any activity on the SCK pin (tried both SERCOM0 and SERCOM5). The SCK pin transitions to HIGH upon plug and it stays there forever (instead of continuously toggling). The loopback test also failed (tests/drivers/spi/spi_loopback). Any idea if the driver is working?