1991/0911/pc/devrtc.c (diff list | history)

pc/devrtc.c on 1991/0911
1991/0911		#include "u.h" #include "lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "errno.h" #include "devtab.h" enum { Paddr= 0x70, /* address port */ Pdata= 0x71, /* data port */ Seconds= 0x00, Minutes= 0x02, Hours= 0x04, Mday= 0x07, Month= 0x08, Year= 0x09, Status= 0x0A, Nbcd= 6, }; typedef struct Rtc Rtc; struct Rtc { int sec; int min; int hour; int mday; int mon; int year; }; QLock rtclock; /* mutex on clock operations */ #define NRTC 1 Dirtab rtcdir[]={ "rtc", {1, 0}, 0, 0600, }; ulong rtc2sec(Rtc*); void sec2rtc(ulong, Rtc*); int *yrsize(int); void rtcreset(void) { } void rtcinit(void) { } Chan* rtcattach(char *spec) { return devattach('r', spec); } Chan* rtcclone(Chan *c, Chan *nc) { return devclone(c, nc); } int rtcwalk(Chan *c, char *name) { return devwalk(c, name, rtcdir, NRTC, devgen); } void rtcstat(Chan *c, char *dp) { devstat(c, dp, rtcdir, NRTC, devgen); } Chan* rtcopen(Chan *c, int omode) { return devopen(c, omode, rtcdir, NRTC, devgen); } void rtccreate(Chan *c, char *name, int omode, ulong perm) { error(Eperm); } void rtcclose(Chan *c) { } #define GETBCD(o) ((bcdclock[o]&0xf) + 10*(bcdclock[o]>>4)) long rtctime(void) { int i,j; uchar ch; uchar bcdclock[Nbcd]; char atime[64]; Rtc rtc; outb(Paddr, Status); while(inb(Pdata) & 1) ; outb(Paddr, Seconds); bcdclock[0] = inb(Pdata); outb(Paddr, Minutes); bcdclock[1] = inb(Pdata); outb(Paddr, Hours); bcdclock[2] = inb(Pdata); outb(Paddr, Mday); bcdclock[3] = inb(Pdata); outb(Paddr, Month); bcdclock[4] = inb(Pdata); outb(Paddr, Year); bcdclock[5] = inb(Pdata); /* * convert from BCD */ rtc.sec = GETBCD(0); rtc.min = GETBCD(1); rtc.hour = GETBCD(2); rtc.mday = GETBCD(3); rtc.mon = GETBCD(4); rtc.year = GETBCD(5); /* * the world starts jan 1 1970 */ if(rtc.year < 70) rtc.year += 2000; else rtc.year += 1900; return rtc2sec(&rtc); } long rtcread(Chan *c, void *buf, long n, ulong offset) { ulong t, ot; if(c->qid.path & CHDIR) return devdirread(c, buf, n, rtcdir, NRTC, devgen); qlock(&rtclock); t = rtctime(); do{ ot = t; t = rtctime(); /* make sure there's no skew */ }while(t != ot); qunlock(&rtclock); n = readnum(offset, buf, n, t, 12); return n; } #define PUTBCD(n,o) bcdclock[o] = (n % 10) | (((n / 10) % 10)<<4) long rtcwrite(Chan *c, void *buf, long n, ulong offset) { Rtc rtc; ulong secs; int i,j; uchar ch; uchar bcdclock[Nbcd]; uchar *nv; char *cp, *ep; if(offset!=0) error(Ebadarg); /* * read the time */ cp = ep = buf; ep += n; while(cp < ep){ if(*cp>='0' && *cp<='9') break; cp++; } secs = strtoul(cp, 0, 0); /* * convert to bcd */ sec2rtc(secs, &rtc); PUTBCD(rtc.sec, 0); PUTBCD(rtc.min, 1); PUTBCD(rtc.hour, 2); PUTBCD(rtc.mday, 3); PUTBCD(rtc.mon, 4); PUTBCD(rtc.year, 5); /* * write the clock */ qlock(&rtclock); outb(Paddr, Seconds); outb(Pdata, bcdclock[0]); outb(Paddr, Minutes); outb(Pdata, bcdclock[1]); outb(Paddr, Hours); outb(Pdata, bcdclock[2]); outb(Paddr, Mday); outb(Pdata, bcdclock[3]); outb(Paddr, Month); outb(Pdata, bcdclock[4]); outb(Paddr, Year); outb(Pdata, bcdclock[5]); qunlock(&rtclock); return n; } void rtcremove(Chan *c) { error(Eperm); } void rtcwstat(Chan *c, char *dp) { error(Eperm); } #define SEC2MIN 60L #define SEC2HOUR (60L*SEC2MIN) #define SEC2DAY (24L*SEC2HOUR) /* * days per month plus days/year */ static int dmsize[] = { 365, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; static int ldmsize[] = { 366, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; /* * return the days/month for the given year */ int * yrsize(int yr) { if((yr % 4) == 0) return ldmsize; else return dmsize; } /* * compute seconds since Jan 1 1970 */ ulong rtc2sec(Rtc *rtc) { ulong secs; int i; int *d2m; secs = 0; /* * seconds per year */ for(i = 1970; i < rtc->year; i++){ d2m = yrsize(i); secs += d2m[0] * SEC2DAY; } /* * seconds per month */ d2m = yrsize(rtc->year); for(i = 1; i < rtc->mon; i++) secs += d2m[i] * SEC2DAY; secs += (rtc->mday-1) * SEC2DAY; secs += rtc->hour * SEC2HOUR; secs += rtc->min * SEC2MIN; secs += rtc->sec; return secs; } /* * compute rtc from seconds since Jan 1 1970 */ void sec2rtc(ulong secs, Rtc *rtc) { int d; long hms, day; int *d2m; /* * break initial number into days */ hms = secs % SEC2DAY; day = secs / SEC2DAY; if(hms < 0) { hms += SEC2DAY; day -= 1; } /* * generate hours:minutes:seconds */ rtc->sec = hms % 60; d = hms / 60; rtc->min = d % 60; d /= 60; rtc->hour = d; /* * year number */ if(day >= 0) for(d = 1970; day >= *yrsize(d); d++) day -= *yrsize(d); else for (d = 1970; day < 0; d--) day += *yrsize(d-1); rtc->year = d; /* * generate month */ d2m = yrsize(rtc->year); for(d = 1; day >= d2m[d]; d++) day -= d2m[d]; rtc->mday = day + 1; rtc->mon = d; return; }