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1995/0108/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	"devtab.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; 
}; 
QLock rtclock;	/* mutex on clock operations */ 
 
 
1995/0108    
enum 
{ 
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	Qrtc = 1, 
	Qnvram, 
 
	Seconds=	0x00, 
	Minutes=	0x02, 
	Hours=		0x04,  
	Mday=		0x07, 
	Month=		0x08, 
	Year=		0x09, 
	Status=		0x0A, 
 
	Nvsize = 4096, 
}; 
 
#define	NRTC	2 
Dirtab rtcdir[]={ 
	"nvram",	{Qnvram, 0},	Nvsize,	0664, 
	"rtc",		{Qrtc, 0},	0,	0664, 
}; 
 
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) 
{ 
	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); 
	} 
	return devopen(c, omode, rtcdir, NRTC, devgen); 
} 
 
void	  
rtccreate(Chan *c, char *name, int omode, ulong perm) 
{ 
	USED(c, name, omode, perm); 
	error(Eperm); 
} 
 
void	  
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); 
} 
 
long	  
rtctime(void) 
{ 
	Rtc rtc; 
	int x; 
 
	/* 
	 *  read and convert from bcd 
	 */ 
	x = splhi(); 
	rtc.sec = bcd2binary(Seconds); 
	rtc.min = bcd2binary(Minutes); 
	rtc.hour = bcd2binary(Hours); 
	rtc.mday = bcd2binary(Mday); 
	rtc.mon = bcd2binary(Month); 
	rtc.year = bcd2binary(Year); 
	splx(x); 
 
	/* 
	 *  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; 
	uchar *f, *to, *e; 
 
	if(c->qid.path & CHDIR) 
		return devdirread(c, buf, n, rtcdir, NRTC, devgen); 
 
	switch(c->qid.path){ 
	case Qrtc: 
		t = rtctime(); 
		do{ 
			ot = t; 
			t = rtctime();	/* make sure there's no skew */ 
		}while(t != ot); 
		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; 
} 
 
1995/0108    
Block* 
rtcbread(Chan *c, long n, ulong offset) 
{ 
	return devbread(c, n, offset); 
} 
 
1993/0916    
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); 
} 
 
 
long	  
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); 
		binary2bcd(Year, rtc.year); 
		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; 
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} 
 
long 
rtcbwrite(Chan *c, Block *bp, ulong offset) 
{ 
	return devbwrite(c, bp, offset); 
1993/0916    
} 
 
void	  
rtcremove(Chan *c) 
{ 
	USED(c); 
	error(Eperm); 
} 
 
void	  
rtcwstat(Chan *c, char *dp) 
{ 
	USED(c, 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; 
} 


source code copyright © 1990-2005 Lucent Technologies; see license
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comments to russ cox (rsc@swtch.com)