ref: b4b4b6cd631e4627f8e581d20fc70d5d13f4de18
dir: /sys/src/9/mtx/devrtc.c/
/* * M48T59/559 Timekeeper */ #include "u.h" #include "../port/lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "../port/error.h" #include "io.h" enum{ STB0 = 0x74, STB1 = 0x75, Data = 0x77, NVOFF= 0, NVLEN= 0x1ff0, /* length in bytes of NV RAM */ /* * register offsets into time of day clock */ NVflags= 0x1ff0, NVwatchdog= 0x1ff7, NVctl= 0x1ff8, NVsec, NVmin, NVhour, NVday, /* (1 = Sun) */ NVmday, /* (1-31) */ NVmon, /* (1-12) */ NVyear, /* (0-99) */ /* NVctl */ RTwrite = (1<<7), RTread = (1<<6), RTsign = (1<<5), RTcal = 0x1f, /* NVwatchdog */ WDsteer = (1<<7), /* 0 -> intr, 1 -> reset */ WDmult = (1<<2), /* 5 bits of multiplier */ WDres0 = (0<<0), /* 1/16 sec resolution */ WDres1 = (1<<0), /* 1/4 sec resolution */ WDres2 = (2<<0), /* 1 sec resolution */ WDres3 = (3<<0), /* 4 sec resolution */ Qdir = 0, Qrtc, Qnvram, }; /* * broken down time */ typedef struct { int sec; int min; int hour; int mday; int mon; int year; } Rtc; QLock rtclock; /* mutex on nvram operations */ static Dirtab rtcdir[]={ ".", {Qdir, 0, QTDIR}, 0, DMDIR|0555, "rtc", {Qrtc, 0}, 0, 0644, "nvram", {Qnvram, 0}, 0, 0600, }; static ulong rtc2sec(Rtc*); static void sec2rtc(ulong, Rtc*); static void setrtc(Rtc*); static void nvcksum(void); static void nvput(int, uchar); static uchar nvget(int); static Chan* rtcattach(char *spec) { return devattach('r', spec); } static Walkqid* rtcwalk(Chan *c, Chan *nc, char **name, int nname) { return devwalk(c, nc, name, nname, rtcdir, nelem(rtcdir), devgen); } static int rtcstat(Chan *c, uchar *dp, int n) { return devstat(c, dp, n, rtcdir, nelem(rtcdir), devgen); } static Chan* rtcopen(Chan *c, int omode) { omode = openmode(omode); switch((ulong)c->qid.path){ case Qrtc: if(strcmp(up->user, eve)!=0 && omode!=OREAD) error(Eperm); break; case Qnvram: if(strcmp(up->user, eve)!=0 || !cpuserver) error(Eperm); } return devopen(c, omode, rtcdir, nelem(rtcdir), devgen); } static void rtcclose(Chan*) { } static long rtcread(Chan *c, void *buf, long n, vlong off) { char *p; ulong t; int i; ulong offset = off; if(c->qid.type & QTDIR) return devdirread(c, buf, n, rtcdir, nelem(rtcdir), devgen); switch((ulong)c->qid.path){ case Qrtc: qlock(&rtclock); t = rtctime(); qunlock(&rtclock); n = readnum(offset, buf, n, t, 12); return n; case Qnvram: offset += NVOFF; if(offset > NVLEN) return 0; if(n > NVLEN - offset) n = NVLEN - offset; p = buf; qlock(&rtclock); for(i = 0; i < n; i++) p[i] = nvget(i+offset); qunlock(&rtclock); return n; } error(Egreg); return -1; /* never reached */ } static long rtcwrite(Chan *c, void *buf, long n, vlong off) { Rtc rtc; ulong secs; char *cp, *ep; int i; ulong offset = off; switch((ulong)c->qid.path){ case Qrtc: 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); /* * write it */ qlock(&rtclock); setrtc(&rtc); qunlock(&rtclock); return n; case Qnvram: offset += NVOFF; if(offset > NVLEN) return 0; if(n > NVLEN - offset) n = NVLEN - offset; qlock(&rtclock); for(i = 0; i < n; i++) nvput(i+offset, ((uchar*)buf)[i]); nvcksum(); qunlock(&rtclock); return n; } error(Egreg); return -1; /* never reached */ } long rtcbwrite(Chan *c, Block *bp, ulong offset) { return devbwrite(c, bp, offset); } Dev rtcdevtab = { 'r', "rtc", devreset, devinit, devshutdown, rtcattach, rtcwalk, rtcstat, rtcopen, devcreate, rtcclose, rtcread, devbread, rtcwrite, devbwrite, devremove, devwstat, }; static void nvput(int offset, uchar val) { outb(STB0, offset); outb(STB1, offset>>8); outb(Data, val); } static uchar nvget(int offset) { outb(STB0, offset); outb(STB1, offset>>8); return inb(Data); } static void nvcksum(void) { } void watchreset(void) { splhi(); nvput(NVwatchdog, WDsteer|(1*WDmult)|WDres0); for(;;); } static int getbcd(int bcd) { return (bcd&0x0f) + 10 * (bcd>>4); } static int putbcd(int val) { return (val % 10) | (((val/10) % 10) << 4); } long rtctime(void) { int ctl; Rtc rtc; /* * convert from BCD */ ctl = nvget(NVctl); ctl &= RTsign|RTcal; nvput(NVctl, ctl|RTread); rtc.sec = getbcd(nvget(NVsec) & 0x7f); rtc.min = getbcd(nvget(NVmin)); rtc.hour = getbcd(nvget(NVhour)); rtc.mday = getbcd(nvget(NVmday)); rtc.mon = getbcd(nvget(NVmon)); rtc.year = getbcd(nvget(NVyear)); if(rtc.year < 70) rtc.year += 2000; else rtc.year += 1900; nvput(NVctl, ctl); return rtc2sec(&rtc); } static void setrtc(Rtc *rtc) { int ctl; ctl = nvget(NVctl); ctl &= RTsign|RTcal; nvput(NVctl, ctl|RTwrite); nvput(NVsec, putbcd(rtc->sec)); nvput(NVmin, putbcd(rtc->min)); nvput(NVhour, putbcd(rtc->hour)); nvput(NVmday, putbcd(rtc->mday)); nvput(NVmon, putbcd(rtc->mon)); nvput(NVyear, putbcd(rtc->year % 100)); nvput(NVctl, ctl); } #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 */ static int * yrsize(int y) { if((y%4) == 0 && ((y%100) != 0 || (y%400) == 0)) return ldmsize; else return dmsize; } /* * compute seconds since Jan 1 1970 */ static 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 */ static 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; }