HelenOS sources

rtc_close          90 uspace/drv/time/cmos-rtc/cmos-rtc.c static void rtc_close(ddf_fun_t *fun);
rtc_close         150 uspace/drv/time/cmos-rtc/cmos-rtc.c 	rtc_dev_ops.close = rtc_close;
HelenOS homepage, sources at GitHub