IG4_REG_FS_SCL_HCNT
reg_write(sc, IG4_REG_FS_SCL_HCNT, sc->cfg.fs_scl_hcnt);
REGDUMP(sc, IG4_REG_FS_SCL_HCNT);
reg_read(sc, IG4_REG_FS_SCL_HCNT) & IG4_SCL_CLOCK_MASK;