RTSX_CHANGE_CLK
RTSX_BITOP(sc, RTSX_CLK_CTL, RTSX_CHANGE_CLK, RTSX_CLK_LOW_FREQ);
rtsx_write(sc, RTSX_CLK_CTL, RTSX_CHANGE_CLK, RTSX_CHANGE_CLK);
rtsx_write(sc, RTSX_CLK_CTL, RTSX_CHANGE_CLK, 0);
rtsx_write(sc, RTSX_CLK_CTL, RTSX_CHANGE_CLK, RTSX_CHANGE_CLK);
rtsx_write(sc, RTSX_CLK_CTL, RTSX_CHANGE_CLK, 0);