From 951ab17262c61dca249baf5aca1810b55117e684 Mon Sep 17 00:00:00 2001 From: cinap_lenrek Date: Wed, 20 Jul 2022 18:49:28 +0000 Subject: [PATCH 1/3] imx8: add simple i2c rtc driver for NXP PCF8523 datasheet: http://nxp.com/docs/en/data-sheet/PCF8523.pdf --- sys/src/9/imx8/devrtc.c | 349 ++++++++++++++++++++++++++++++++++++++++ sys/src/9/imx8/reform | 1 + 2 files changed, 350 insertions(+) create mode 100644 sys/src/9/imx8/devrtc.c diff --git a/sys/src/9/imx8/devrtc.c b/sys/src/9/imx8/devrtc.c new file mode 100644 index 000000000..87b4c5533 --- /dev/null +++ b/sys/src/9/imx8/devrtc.c @@ -0,0 +1,349 @@ +/* + * NXP PCF8523 real time clock + */ + +#include "u.h" +#include "../port/lib.h" +#include "mem.h" +#include "dat.h" +#include "fns.h" +#include "../port/error.h" +#include "../port/i2c.h" + +enum { + Seconds= 0x03, + Minutes= 0x04, + Hours= 0x05, + Mday= 0x06, + Wday= 0x07, + Month= 0x08, + Year= 0x09, + Nbcd= 1+Year-Seconds, +}; + +typedef struct Rtc Rtc; +struct Rtc +{ + int sec; + int min; + int hour; + int mday; + int wday; + int mon; + int year; +}; + +enum{ + Qdir = 0, + Qrtc, +}; + +Dirtab rtcdir[]={ + ".", {Qdir, 0, QTDIR}, 0, 0555, + "rtc", {Qrtc, 0}, 0, 0664, +}; + +static ulong rtc2sec(Rtc*); +static void sec2rtc(ulong, Rtc*); +static I2Cdev *i2c; + +static Chan* +rtcattach(char* spec) +{ + i2c = i2cdev(i2cbus("i2c3"), 0x68); + if(i2c == nil) + error(Enonexist); + + i2c->subaddr = 1; + i2c->size = 0x14; + + 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; + } + return devopen(c, omode, rtcdir, nelem(rtcdir), devgen); +} + +static void +rtcclose(Chan*) +{ +} + +#define GETBCD(o) (((bcdclock[o]&0xf)%10) + 10*((bcdclock[o]>>4)%10)) + +static long +_rtctime(void) +{ + uchar bcdclock[Nbcd]; + Rtc rtc; + + /* read clock values */ + i2crecv(i2c, bcdclock, Nbcd, Seconds); + + /* + * convert from BCD + */ + rtc.sec = GETBCD(Seconds-Seconds) % 60; + rtc.min = GETBCD(Minutes-Seconds) % 60; + rtc.hour = GETBCD(Hours-Seconds) % 24; + rtc.mday = GETBCD(Mday-Seconds); + rtc.wday = GETBCD(Wday-Seconds) % 7; + rtc.mon = GETBCD(Month-Seconds); + rtc.year = GETBCD(Year-Seconds) % 100; + + /* + * the world starts jan 1 1970 + */ + if(rtc.year < 70) + rtc.year += 2000; + else + rtc.year += 1900; + return rtc2sec(&rtc); +} + +long +rtctime(void) +{ + int i; + long t, ot; + + /* 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"); + + return t; +} + +static long +rtcread(Chan* c, void* buf, long n, vlong off) +{ + ulong offset = off; + + if(c->qid.type & QTDIR) + return devdirread(c, buf, n, rtcdir, nelem(rtcdir), devgen); + + switch((ulong)c->qid.path){ + case Qrtc: + return readnum(offset, buf, n, rtctime(), 12); + } + 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) +{ + Rtc rtc; + ulong secs; + char *cp, sbuf[32]; + uchar bcdclock[Nbcd]; + ulong offset = off; + + if(offset!=0) + error(Ebadarg); + + + switch((ulong)c->qid.path){ + case Qrtc: + if(n >= sizeof(sbuf)) + error(Ebadarg); + strncpy(sbuf, buf, n); + sbuf[n] = '\0' + for(cp = sbuf; *cp != '\0'; cp++) + if(*cp >= '0' && *cp <= '9') + break; + secs = strtoul(cp, 0, 0); + + /* + * convert to bcd + */ + sec2rtc(secs, &rtc); + + PUTBCD(rtc.sec, Seconds-Seconds); + PUTBCD(rtc.min, Minutes-Seconds); + PUTBCD(rtc.hour, Hours-Seconds); + PUTBCD(rtc.mday, Mday-Seconds); + PUTBCD(rtc.wday, Wday-Seconds); + PUTBCD(rtc.mon, Month-Seconds); + PUTBCD(rtc.year, Year-Seconds); + + /* + * write the clock + */ + i2csend(i2c, bcdclock, Nbcd, Seconds); + + return n; + } + error(Ebadarg); + return 0; +} + +Dev rtcdevtab = { + 'r', + "rtc", + + devreset, + devinit, + 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; + } + + /* + * 19700101 was thursday + */ + rtc->wday = (day + 7340036L) % 7; + + /* + * 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; +} diff --git a/sys/src/9/imx8/reform b/sys/src/9/imx8/reform index 186075169..8dcc118f6 100644 --- a/sys/src/9/imx8/reform +++ b/sys/src/9/imx8/reform @@ -20,6 +20,7 @@ dev uart usb i2c + rtc devi2c sd link From 4063334e6f121b42b0e28fcbdd3108d040893fee Mon Sep 17 00:00:00 2001 From: cinap_lenrek Date: Wed, 20 Jul 2022 18:52:02 +0000 Subject: [PATCH 2/3] pc/rtc: make sure string is NUL terminates for rtc write --- sys/src/9/pc/devrtc.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/sys/src/9/pc/devrtc.c b/sys/src/9/pc/devrtc.c index 5d092066f..f8de9531d 100644 --- a/sys/src/9/pc/devrtc.c +++ b/sys/src/9/pc/devrtc.c @@ -227,26 +227,25 @@ rtcwrite(Chan* c, void* buf, long n, vlong off) char *a, *start; Rtc rtc; ulong secs; + char *cp, sbuf[32]; 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') + if(n >= sizeof(sbuf)) + error(Ebadarg); + strncpy(sbuf, buf, n); + sbuf[n] = '\0'; + for(cp = sbuf; *cp != '\0'; cp++) + if(*cp >= '0' && *cp <= '9') break; - cp++; - } secs = strtoul(cp, 0, 0); /* From 3cc07dddfbc2c5cb57fcd1849df55fca57f119db Mon Sep 17 00:00:00 2001 From: cinap_lenrek Date: Thu, 21 Jul 2022 00:44:34 +0000 Subject: [PATCH 3/3] devrtc: fix mistake. --- sys/src/9/imx8/devrtc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sys/src/9/imx8/devrtc.c b/sys/src/9/imx8/devrtc.c index 87b4c5533..a30c6cfef 100644 --- a/sys/src/9/imx8/devrtc.c +++ b/sys/src/9/imx8/devrtc.c @@ -177,7 +177,7 @@ rtcwrite(Chan* c, void* buf, long n, vlong off) if(n >= sizeof(sbuf)) error(Ebadarg); strncpy(sbuf, buf, n); - sbuf[n] = '\0' + sbuf[n] = '\0'; for(cp = sbuf; *cp != '\0'; cp++) if(*cp >= '0' && *cp <= '9') break;