SSSR
} while ((ispi_read(sc, SSSR) & SSSR_BSY) && --tries);
ispi_write(sc, SSSR, SSSR_ROR);
while ((ispi_read(sc, SSSR) & SSSR_BSY) && --tries)
return ispi_read(sc, SSSR);
ispi_write(sc, SSSR, SSSR_TUR | SSSR_TINT | SSSR_PINT | SSSR_ROR);