ref: 951b9aa55bdcc5a930dc0648aaf233e76b093086
dir: /sys/src/9/omap/devrtctwl.c/
#include "u.h" #include "../port/lib.h" #include "../port/error.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "io.h" #include "../port/i2c.h" enum { Rsec = 0x1c, Rmin = 0x1d, Rhour = 0x1e, Rday = 0x1f, Rmonth = 0x20, Ryear = 0x21, Rweeks = 0x22, Rctrl = 0x29, Cget = 1<<6, Qdir = 0, Qrtc, SecMin = 60, SecHour = 60*SecMin, SecDay = 24*SecHour, }; typedef struct Ctlr Ctlr; struct Ctlr { I2Cdev *dev; int sec; int min; int hour; int day; int month; int year; }; static Ctlr ctlr; 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 }; static Dirtab rtctab[] = { ".", {Qdir, 0, QTDIR}, 0, 0555, "rtc", {Qrtc, 0, QTFILE}, 0, 0440, }; #define bcddec(x) (((x) & 0xf) + ((x) >> 4) * 10) #define bcdenc(x) (((x / 10) << 4) + (x) % 10) #define leap(x) (((x) % 4) == 0 && ((x % 100) != 0 || (x % 400) == 0)) static u8int csr8r(Ctlr *ctlr, u8int r) { uchar buf; i2crecv(ctlr->dev, &buf, sizeof(buf), r); return buf; } static u8int csr8w(Ctlr *ctlr, u8int r, u8int w) { i2csend(ctlr->dev, &w, sizeof(w), r); return w; } static vlong rtcsnarf(void) { vlong s; int i; /* latch and snarf */ csr8w(&ctlr, Rctrl, csr8r(&ctlr, Rctrl) | Cget); ctlr.sec = bcddec(csr8r(&ctlr, Rsec)) % 60; ctlr.min = bcddec(csr8r(&ctlr, Rmin)) % 60; ctlr.hour = bcddec(csr8r(&ctlr, Rhour)) % 24; ctlr.day = bcddec(csr8r(&ctlr, Rday)); ctlr.month = bcddec(csr8r(&ctlr, Rmonth)); ctlr.year = bcddec(csr8r(&ctlr, Ryear)) % 100; ctlr.year += 2000; /* seconds per year */ s = 0; for(i = 1970; i < ctlr.year; i++) { if(leap(i)) s += ldmsize[0] * SecDay; else s += dmsize[0] * SecDay; } /* seconds per month */ for(i = 1; i < ctlr.month; i++) { if(leap(ctlr.year)) s += ldmsize[i] * SecDay; else s += dmsize[i] * SecDay; } /* days, hours, minutes, seconds */ s += (ctlr.day - 1) * SecDay; s += ctlr.hour * SecHour; s += ctlr.min * SecMin; s += ctlr.sec; return s; } static void rtcreset(void) { ctlr.dev = i2cdev(i2cbus("i2c1"), 0x4b); if(!ctlr.dev) return; ctlr.dev->subaddr = 1; ctlr.dev->size = 0x100; } static void rtcshutdown(void) { } static Chan * rtcattach(char *spec) { if(!ctlr.dev) error(Enonexist); return devattach('r', spec); } static Walkqid * rtcwalk(Chan *c, Chan *nc, char **name, int nname) { return devwalk(c, nc, name, nname, rtctab, nelem(rtctab), devgen); } static int rtcstat(Chan *c, uchar *dp, int n) { return devstat(c, dp, n, rtctab, nelem(rtctab), devgen); } static Chan * rtcopen(Chan *c, int mode) { mode = openmode(mode); if(c->qid.path == Qrtc) { if(!iseve() && mode != OREAD) error(Eperm); } return devopen(c, mode, rtctab, nelem(rtctab), devgen); } static void rtcclose(Chan *) { } static long rtcread(Chan *c, void *a, long n, vlong off) { if(c->qid.path == Qdir) return devdirread(c, a, n, rtctab, nelem(rtctab), devgen); if(c->qid.path == Qrtc) return readnum(off, a, n, rtcsnarf(), 12); error(Egreg); return 0; } static long rtcwrite(Chan *, void *, long, vlong) { error(Egreg); return 0; } Dev rtctwldevtab = { 'r', "rtc", rtcreset, devinit, rtcshutdown, rtcattach, rtcwalk, rtcstat, rtcopen, devcreate, rtcclose, rtcread, devbread, rtcwrite, devbwrite, devremove, devwstat, };