1991/0727/pc/devfloppy.c (diff list | history)

pc/devfloppy.c on 1991/0727
1991/0727		#include "u.h" #include "lib.h" #include "mem.h" #include "dat.h" #include "fns.h" #include "io.h" #include "ureg.h" typedef struct Drive Drive; typedef struct Controller Controller; typedef struct Type Type; enum { Fmotor= 0x3f2, /* motor port */ Fintena= 0x4, /* enable floppy interrupt */ Fena= 0x8, /* 0 == reset controller */ Fstatus= 0x3f4, /* controller main status port */ Fready= 0x80, /* ready to be touched */ Ffrom= 0x40, /* data from controller */ Fbusy= 0x10, /* operation not over */ Fdata= 0x3f5, /* controller data port */ Frecal= 0x7, /* recalibrate cmd */ Fseek= 0xf, /* seek cmd */ Fsense= 0x8, /* sense cmd */ Fread= 0x66, /* read cmd */ Fwrite= 0x47, /* write cmd */ Fmulti= 0x80, /* or'd with Fread or Fwrite for multi-head */ DMAmode0= 0xb, DMAmode1= 0xc, DMAaddr= 0x4, DMAtop= 0x81, DMAinit= 0xa, DMAcount= 0x5, Nfloppy= 4, /* floppies/controller */ /* sector size encodings */ S128= 0, S256= 1, S512= 2, S1024= 3, /* status 0 byte */ Drivemask= 3<<0, Seekend= 1<<5, Codemask= (3<<6)|(3<<3), }; /* * floppy types */ struct Type { char *name; int bytes; /* bytes/sector */ int sectors; /* sectors/track */ int heads; /* number of heads */ int steps; /* steps per cylinder */ int tracks; /* tracks/disk */ int gpl; /* intersector gap length for read/write */ int fgpl; /* intersector gap length for format */ long cap; /* drive capacity in bytes */ }; Type floppytype[] = { { "MF2HD", S512, 18, 2, 1, 80, 0x1B, 0x54, 512*2*18*80 }, { "MF2DD", S512, 9, 2, 1, 80, 0x1B, 0x54, 512*2*9*80 }, { "F2HD", S512, 15, 2, 1, 80, 0x2A, 0x50, 512*15*2*80 }, { "F2DD", S512, 8, 2, 1, 40, 0x2A, 0x50, 512*8*2*40 }, { "F1DD", S512, 8, 1, 1, 40, 0x2A, 0x50, 512*8*1*40 }, }; static int secbytes[] = { 128, 256, 512, 1024 }; /* * a floppy drive */ struct Drive { QLock; Type *t; int dev; ulong lasttouched; /* time last touched */ int motoron; /* motor is on */ int cyl; /* current cylinder */ long offset; /* current offset */ int confused; /* needs to be recalibrated (or worse) */ int tcyl; /* target cylinder */ int thead; /* target head */ int tsec; /* target sector */ long len; int busy; /* true if drive is seeking */ Rendez r; /* waiting for operation termination */ }; /* * NEC PD765A controller for 4 floppys */ struct Controller { QLock; Drive d[Nfloppy]; /* the floppy drives */ int busy; /* true if a read or write in progress */ uchar stat[8]; /* status of an operation */ int confused; }; Controller floppy[1]; /* * start a floppy drive's motor. set an alarm for 1 second later to * mark it as started (we get no interrupt to tell us). * * assume the caller qlocked the drive. */ void floppystart(Drive *dp) { int cmd; dp->lasttouched = m->ticks; if(dp->motoron) return; cmd = (1<<(dp->dev+4)) | Fintena | Fena | dp->dev; outb(Fmotor, cmd); dp->busy = 1; tsleep(&dp->r, noreturn, 0, 1000); dp->motoron = 1; dp->busy = 0; dp->lasttouched = m->ticks; } /* * stop the floppy if it hasn't been used in 5 seconds */ void floppystop(Drive *dp) { int cmd; if(!canqlock(dp)) return; cmd = Fintena | Fena | dp->dev; outb(Fmotor, cmd); dp->motoron = 0; } void floppykproc(Alarm* a) { Drive *dp; if(waserror()) for(dp = floppy.d; dp < &floppy.d[Nfloppy]; dp++){ if(dp->motoron && TK2SEC(m->ticks - dp->lasttouched) > 5) floppystop(dp); } alarm(5*1000, floppyalarm, 0); cancel(a); } int floppysend(int data) { int tries; uchar c; for(tries = 0; tries < 100; tries++){ /* * see if its ready for data */ c = inb(Fstatus); if((c&(Ffrom|Fready)) != Fready) continue; /* * send the data */ outb(Fdata, data); return 0; } return -1; } int floppyrcv(void) { int tries; uchar c; for(tries = 0; tries < 100; tries++){ /* * see if its ready for data */ c = inb(Fstatus); if((c&(Ffrom|Fready)) != (Ffrom|Fready)) continue; /* * get data */ return inb(Fdata)&0xff; } return -1; } int floppyrdstat(int n) { int i; int c; for(i = 0; i < n; i++){ c = floppyrcv(); if(c < 0) return -1; floppy.stat[i] = c; } return 0; } void floppypos(Drive *dp, long off) { int lsec; int end; int cyl; lsec = off/secbytes[dp->t->bytes]; dp->tcyl = lsec/(dp->t->sectors*dp->t->heads); dp->tsec = (lsec % dp->t->sectors) + 1; dp->thead = (lsec/dp->t->sectors) % dp->t->heads; /* * can't read across cylinder boundaries. * if so, decrement the bytes to be read. */ lsec = (off+dp->len)/secbytes[dp->t->bytes]; cyl = lsec/(dp->t->sectors*dp->t->heads); if(cyl != dp->tcyl){ dp->len -= (lsec % dp->t->sectors)*secbytes[dp->t->bytes]; dp->len -= ((lsec/dp->t->sectors) % dp->t->heads)*secbytes[dp->t->bytes] *dp->t->sectors; } dp->lasttouched = m->ticks; floppy.intr = 0; } void floppywait(void) { int tries; for(tries = 0; tries < 100 && floppy.intr == 0; tries++) delay(5); if(tries >= 100) print("tired floopy\n"); floppy.intr = 0; } int floppysense(Drive *dp) { /* * ask for floppy status */ if(floppysend(Fsense) < 0){ floppy.confused = 1; return -1; } if(floppyrdstat(2) < 0){ floppy.confused = 1; dp->confused = 1; return -1; } /* * make sure it's the right drive */ if((floppy.stat[0] & Drivemask) != dp-floppy.d){ print("sense failed\n"); dp->confused = 1; return -1; } return 0; } int floppyrecal(Drive *dp) { floppy.intr = 0; if(floppysend(Frecal) < 0 || floppysend(dp - floppy.d) < 0){ floppy.confused = 0; return -1; } floppywait(); /* * get return values */ if(floppysense(dp) < 0) return -1; /* * see if it worked */ if((floppy.stat[0] & (Codemask|Seekend)) != Seekend){ print("recalibrate failed\n"); dp->confused = 1; return -1; } /* * see what cylinder we got to */ dp->tcyl = 0; dp->cyl = floppy.stat[1]/dp->t->steps; if(dp->cyl != dp->tcyl){ print("recalibrate went to wrong cylinder %d\n", dp->cyl); dp->confused = 1; return -1; } dp->confused = 0; return 0; } void floppyinit(void) { Drive *dp; for(dp = floppy.d; dp < &floppy.d[Nfloppy]; dp++){ dp->t = &floppytype[0]; dp->cyl = -1; dp->motoron = 1; floppystop(dp); } setvec(22, floppyintr); alarm(5*1000, floppyalarm, (void *)0); } void floppyreset(void) { Drive *dp; /* * reset the floppy if'n it's confused */ if(floppy.confused){ /* reset controller and turn all motors off */ floppy.intr = 0; splhi(); outb(Fmotor, 0); delay(1); outb(Fmotor, Fintena|Fena); spllo(); for(dp = floppy.d; dp < &floppy.d[Nfloppy]; dp++){ dp->motoron = 0; dp->confused = 1; } floppywait(); floppy.confused = 0; } /* * recalibrate any confused drives */ for(dp = floppy.d; floppy.confused == 0 && dp < &floppy.d[Nfloppy]; dp++){ if(dp->confused == 0) floppyrecal(dp); } } long floppyseek(int dev, long off) { Drive *dp; dp = &floppy.d[dev]; if(floppy.confused || dp->confused) floppyreset(); floppystart(dp); floppypos(dp, off); if(dp->cyl == dp->tcyl){ dp->offset = off; return off; } /* * tell floppy to seek */ if(floppysend(Fseek) < 0 || floppysend((dp->thead<<2) | dev) < 0 || floppysend(dp->tcyl * dp->t->steps) < 0){ print("seek cmd failed\n"); floppy.confused = 1; return -1; } /* * wait for interrupt */ floppywait(); /* * get floppy status */ if(floppysense(dp) < 0) return -1; /* * see if it worked */ if((floppy.stat[0] & (Codemask|Seekend)) != Seekend){ print("seek failed\n"); dp->confused = 1; return -1; } /* * see what cylinder we got to */ dp->cyl = floppy.stat[1]/dp->t->steps; if(dp->cyl != dp->tcyl){ print("seek went to wrong cylinder %d instead of %d\n", dp->cyl, dp->tcyl); dp->confused = 1; return -1; } dp->offset = off; return dp->offset; } long floppyxfer(Drive *dp, int cmd, void *a, long n) { int dev; ulong addr; long offset; addr = (ulong)a; dev = dp - floppy.d; /* * dma can't cross 64 k boundaries */ if((addr & 0xffff0000) != ((addr+n) & 0xffff0000)) n -= (addr+n)&0xffff; dp->len = n; floppyseek(dev, dp->offset); /* print("tcyl %d, thead %d, tsec %d, addr %lux, n %d\n", dp->tcyl, dp->thead, dp->tsec, addr, n);/**/ /* * set up the dma */ outb(DMAmode1, cmd==Fread ? 0x46 : 0x4a); outb(DMAmode0, cmd==Fread ? 0x46 : 0x4a); outb(DMAaddr, addr); outb(DMAaddr, addr>>8); outb(DMAtop, addr>>16); outb(DMAcount, n-1); outb(DMAcount, (n-1)>>8); outb(DMAinit, 2); /* * tell floppy to go */ cmd = cmd | (dp->t->heads > 1 ? Fmulti : 0); if(floppysend(cmd) < 0 || floppysend((dp->thead<<2) | dev) < 0 || floppysend(dp->tcyl * dp->t->steps) < 0 || floppysend(dp->thead) < 0 || floppysend(dp->tsec) < 0 || floppysend(dp->t->bytes) < 0 || floppysend(dp->t->sectors) < 0 || floppysend(dp->t->gpl) < 0 || floppysend(0xFF) < 0){ print("xfer cmd failed\n"); floppy.confused = 1; return -1; } floppywait(); /* * get status */ if(floppyrdstat(7) < 0){ print("xfer status failed\n"); floppy.confused = 1; return -1; } if((floppy.stat[0] & Codemask)!=0 || floppy.stat[1] || floppy.stat[2]){ print("xfer failed %lux %lux %lux\n", floppy.stat[0], floppy.stat[1], floppy.stat[2]); dp->confused = 1; return -1; } offset = (floppy.stat[3]/dp->t->steps) * dp->t->heads + floppy.stat[4]; offset = offset*dp->t->sectors + floppy.stat[5] - 1; offset = offset * secbytes[floppy.stat[6]]; if(offset != dp->offset+n){ print("new offset %d instead of %d\n", offset, dp->offset+dp->len); dp->confused = 1; return -1;/**/ } dp->offset += dp->len; return dp->len; } long floppyread(int dev, void *a, long n) { Drive *dp; long rv, i; uchar *aa = a; dp = &floppy.d[dev]; for(rv = 0; rv < n; rv += i){ i = floppyxfer(dp, Fread, aa+rv, n-rv); if(i <= 0) break; } return rv; } void floppyintr(Ureg *ur) { floppy.intr = 1; }