1997/0401/carrera/devrtc.c (diff list | history)

carrera/devrtc.c on 1993/0916
1993/0916		#include "u.h" #include "../port/lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "../port/error.h" #include "io.h" /* * real time clock and non-volatile ram */ typedef struct Rtc Rtc; struct Rtc { int sec; int min; int hour; int mday; int mon; int year; };
1997/0327		static QLock rtclock; /* mutex on clock operations */
1993/0916
1995/0108		enum {
1993/0916		Qrtc = 1, Qnvram, Seconds= 0x00, Minutes= 0x02, Hours= 0x04, Mday= 0x07, Month= 0x08, Year= 0x09, Status= 0x0A, Nvsize = 4096, }; Dirtab rtcdir[]={ "nvram", {Qnvram, 0}, Nvsize, 0664, "rtc", {Qrtc, 0}, 0, 0664, };
1997/0327		static ulong rtc2sec(Rtc*); static void sec2rtc(ulong, Rtc*);
1993/0916
1997/0327		static Chan*
1993/0916		rtcattach(char *spec) { return devattach('r', spec); }
1997/0327		static int
1993/0916		rtcwalk(Chan *c, char *name) {
1997/0327		return devwalk(c, name, rtcdir, nelem(rtcdir), devgen);
1993/0916		}
1997/0327		static void
1993/0916		rtcstat(Chan *c, char *dp) {
1997/0327		devstat(c, dp, rtcdir, nelem(rtcdir), devgen);
1993/0916		}
1997/0327		static Chan*
1993/0916		rtcopen(Chan *c, int omode) { omode = openmode(omode); switch(c->qid.path){ case Qrtc: if(strcmp(up->user, eve)!=0 && omode!=OREAD) error(Eperm); break; case Qnvram: if(strcmp(up->user, eve)!=0) error(Eperm); }
1997/0327		return devopen(c, omode, rtcdir, nelem(rtcdir), devgen);
1993/0916		}
1997/0327		static void
1993/0916		rtcclose(Chan *c) { USED(c); } static uchar bcd2binary(int reg) { uchar x;
1994/0225
1993/0916		x = (*(uchar*)Rtcindex)&~0x7f; *(uchar*)Rtcindex = x|reg; x = *(uchar*)Rtcdata; return (x&0xf) + 10*(x>>4); }
1997/0401		static long _rtctime(void)
1993/0916		{ Rtc rtc;
1997/0401		int i, x;
1993/0916
1997/0401		for(i = 0; i < 10000; i++){ x = (*(uchar*)Rtcindex)&~0x7f; *(uchar*)Rtcindex = x|Status; x = *(uchar*)Rtcdata; if(x & 0x80) continue;
1993/0916
1997/0401		/* * read and convert from bcd */ rtc.sec = bcd2binary(Seconds); rtc.min = bcd2binary(Minutes); rtc.hour = bcd2binary(Hours); rtc.mday = bcd2binary(Mday); rtc.mon = bcd2binary(Month); rtc.year = bcd2binary(Year)+1970; x = (*(uchar*)Rtcindex)&~0x7f; *(uchar*)Rtcindex = x|Status; x = *(uchar*)Rtcdata; if((x & 0x80) == 0) break; }
1993/0916		return rtc2sec(&rtc); }
1997/0401		static Lock rtlock; long rtctime(void) { int i; long t, ot; ilock(&rtlock); /* loop till we get two reads in a row the same */ t = _rtctime(); for(i = 0; i < 100; i++){ ot = t; t = _rtctime(); if(ot == t) break; } if(i == 100) print("we are boofheads\n"); iunlock(&rtlock); return t; }
1997/0327		static long
1993/0916		rtcread(Chan *c, void *buf, long n, ulong offset) {
1997/0401		ulong t;
1993/0916		uchar *f, *to, *e; if(c->qid.path & CHDIR)
1997/0327		return devdirread(c, buf, n, rtcdir, nelem(rtcdir), devgen);
1993/0916		switch(c->qid.path){ case Qrtc:
1997/0401		qlock(&rtclock);
1993/0916		t = rtctime();
1997/0401		qunlock(&rtclock);
1993/0916		n = readnum(offset, buf, n, t, 12); return n; case Qnvram: if(offset > Nvsize) return -1; if(offset + n > Nvsize) n = Nvsize - offset; f = (uchar*)Nvram+offset; to = buf; e = f + n; while(f < e) *to++ = *f++; return n; } error(Ebadarg); return 0; } static void binary2bcd(int reg, uchar val) { uchar x; x = (*(uchar*)Rtcindex)&~0x7f; *(uchar*)Rtcindex = x|reg; *(uchar*)Rtcdata = (val % 10) | (((val / 10) % 10)<<4); }
1997/0327		static long
1993/0916		rtcwrite(Chan *c, void *buf, long n, ulong offset) { Rtc rtc; ulong secs; char *cp, *ep; uchar *f, *t, *e; int s; USED(c); switch(c->qid.path){ case Qrtc: /* * read the time */ cp = ep = buf; ep += n; while(cp < ep){ if(*cp>='0' && *cp<='9') break; cp++; } secs = strtoul(cp, 0, 0); sec2rtc(secs, &rtc); /* * convert to bcd */ s = splhi(); binary2bcd(Seconds, rtc.sec); binary2bcd(Minutes, rtc.min); binary2bcd(Hours, rtc.hour); binary2bcd(Mday, rtc.mday); binary2bcd(Month, rtc.mon);
1997/0401		binary2bcd(Year, rtc.year-1970);
1993/0916		splx(s); return n; case Qnvram: if(offset > Nvsize) return -1; if(offset + n > Nvsize) n = Nvsize - offset; t = (uchar*)Nvram+offset; f = buf; e = f + n; while(f < e) *t++ = *f++; return n; } error(Ebadarg); return 0;
1995/0108		}
1997/0327		Dev rtcdevtab = { devreset, devinit, rtcattach, devclone, rtcwalk, rtcstat, rtcopen, devcreate, rtcclose, rtcread, devbread, rtcwrite, devbwrite, devremove, devwstat, };
1993/0916		#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 */
1997/0327		static int*
1993/0916		yrsize(int yr) { if((yr % 4) == 0) return ldmsize; else return dmsize; } /* * compute seconds since Jan 1 1970 */
1997/0327		static ulong
1993/0916		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 */
1997/0327		static void
1993/0916		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; }