ref: d4bc9052beb3305d64a353a16641740380eb87af
dir: /sys/src/9/pc/devrtc.c/
#include "u.h" #include "../port/lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "../port/error.h" /* * real time clock and non-volatile ram */ enum { Paddr= 0x70, /* address port */ Pdata= 0x71, /* data port */ Seconds= 0x00, Minutes= 0x02, Hours= 0x04, Mday= 0x07, Month= 0x08, Year= 0x09, Status= 0x0A, Nvoff= 128, /* where usable nvram lives */ Nvsize= 256, Nbcd= 6, }; typedef struct Rtc Rtc; struct Rtc { int sec; int min; int hour; int mday; int mon; int year; }; enum{ Qdir = 0, Qrtc, Qnvram, }; Dirtab rtcdir[]={ ".", {Qdir, 0, QTDIR}, 0, 0555, "nvram", {Qnvram, 0}, Nvsize, 0664, "rtc", {Qrtc, 0}, 0, 0664, }; static ulong rtc2sec(Rtc*); static void sec2rtc(ulong, Rtc*); void rtcinit(void) { if(ioalloc(Paddr, 2, 0, "rtc/nvr") < 0) panic("rtcinit: ioalloc failed"); } 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) error(Eperm); } return devopen(c, omode, rtcdir, nelem(rtcdir), devgen); } static void rtcclose(Chan*) { } #define GETBCD(o) ((bcdclock[o]&0xf) + 10*(bcdclock[o]>>4)) static long _rtctime(void) { uchar bcdclock[Nbcd]; Rtc rtc; int i; /* don't do the read until the clock is no longer busy */ for(i = 0; i < 10000; i++){ outb(Paddr, Status); if(inb(Pdata) & 0x80) continue; /* read clock values */ 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); outb(Paddr, Status); if((inb(Pdata) & 0x80) == 0) break; } /* * 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); } static Lock nvrtlock; long rtctime(void) { int i; long t, ot; ilock(&nvrtlock); /* 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(&nvrtlock); return t; } static long rtcread(Chan* c, void* buf, long n, vlong off) { ulong t; char *a, *start; ulong offset = off; if(c->qid.type & QTDIR) return devdirread(c, buf, n, rtcdir, nelem(rtcdir), devgen); switch((ulong)c->qid.path){ case Qrtc: t = rtctime(); n = readnum(offset, buf, n, t, 12); return n; case Qnvram: if(n == 0) return 0; if(n > Nvsize) n = Nvsize; a = start = smalloc(n); ilock(&nvrtlock); for(t = offset; t < offset + n; t++){ if(t >= Nvsize) break; outb(Paddr, Nvoff+t); *a++ = inb(Pdata); } iunlock(&nvrtlock); if(waserror()){ free(start); nexterror(); } memmove(buf, start, t - offset); poperror(); free(start); return t - offset; } error(Ebadarg); return 0; } #define PUTBCD(n,o) bcdclock[o] = (n % 10) | (((n / 10) % 10)<<4) static long rtcwrite(Chan* c, void* buf, long n, vlong off) { int t; char *a, *start; Rtc rtc; ulong secs; uchar bcdclock[Nbcd]; char *cp, *ep; ulong offset = off; if(offset!=0) error(Ebadarg); switch((ulong)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); /* * 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 */ ilock(&nvrtlock); 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]); iunlock(&nvrtlock); return n; case Qnvram: if(n == 0) return 0; if(n > Nvsize) n = Nvsize; start = a = smalloc(n); if(waserror()){ free(start); nexterror(); } memmove(a, buf, n); poperror(); ilock(&nvrtlock); for(t = offset; t < offset + n; t++){ if(t >= Nvsize) break; outb(Paddr, Nvoff+t); outb(Pdata, *a++); } iunlock(&nvrtlock); free(start); return t - offset; } error(Ebadarg); return 0; } Dev rtcdevtab = { 'r', "rtc", devreset, rtcinit, devshutdown, rtcattach, rtcwalk, rtcstat, rtcopen, devcreate, rtcclose, rtcread, devbread, rtcwrite, devbwrite, devremove, devwstat, }; #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; } uchar nvramread(int addr) { uchar data; ilock(&nvrtlock); outb(Paddr, addr); data = inb(Pdata); iunlock(&nvrtlock); return data; } void nvramwrite(int addr, uchar data) { ilock(&nvrtlock); outb(Paddr, addr); outb(Pdata, data); iunlock(&nvrtlock); }