Subversion Repositories planix.SVN

/*
 * raspberry pi doesn't have a realtime clock
 * fake a crude approximation from the kernel build time
 */

#include        "u.h"
#include        "../port/lib.h"
#include        "mem.h"
#include        "dat.h"
#include        "fns.h"
#include        "../port/error.h"

enum{
        Qdir = 0,
        Qrtc,
};

Dirtab rtcdir[]={
        ".",    {Qdir, 0, QTDIR},       0,      0555,
        "rtc",          {Qrtc, 0},      0,      0664,
};

extern ulong kerndate;

static ulong rtcsecs;

static void
rtctick(void)
{
        rtcsecs++;
}

static void
rtcinit(void)
{
        rtcsecs = kerndate;
        addclock0link(rtctick, 1000);
}

static long
rtcread(Chan *c, void *a, long n, vlong offset)
{
        if(c->qid.type & QTDIR)
                return devdirread(c, a, n, rtcdir, nelem(rtcdir), devgen);

        switch((ulong)c->qid.path){
        case Qrtc:
                return readnum((ulong)offset, a, n, rtcsecs, 12);
        }
        error(Ebadarg);
        return 0;
}

static long
rtcwrite(Chan*c, void *a, long n, vlong)
{
        char b[13];
        ulong i;

        switch((ulong)c->qid.path){
        case Qrtc:
                if(n >= sizeof(b))
                        error(Ebadarg);
                strncpy(b, (char*)a, n);
                i = strtol(b, 0, 0);
                if(i <= 0)
                        error(Ebadarg);
                rtcsecs = i;
                return n;
        }
        error(Eperm);
        return 0;
}

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)
{
        return devopen(c, omode, rtcdir, nelem(rtcdir), devgen);
}

static void      
rtcclose(Chan*)
{
}

Dev fakertcdevtab = {
        'r',
        "rtc",

        devreset,
        rtcinit,
        devshutdown,
        rtcattach,
        rtcwalk,
        rtcstat,
        rtcopen,
        devcreate,
        rtcclose,
        rtcread,
        devbread,
        rtcwrite,
        devbwrite,
        devremove,
        devwstat,
};