REG_BRT_A
rval |= lm3630a_write(pchip, REG_BRT_A, pdata->leda_init_brt);
ret = lm3630a_write(pchip, REG_BRT_A, brightness);
rval = lm3630a_read(pchip, REG_BRT_A);
rval = lm3630a_write(pchip, REG_BRT_A, 0);