typedef struct FController FController;

typedef struct FController FController;
typedef struct FDrive FDrive;
typedef struct FType FType;

static void floppyintr(Ureg*);
static void floppyon(FDrive*);
static void floppyoff(FDrive*);
static void floppysetdef(FDrive*);

/*
* a floppy drive
*/
struct FDrive
{
FType *t; /* floppy type */
int dt; /* drive type */
int dev;

ulong lasttouched; /* time last touched */
int cyl; /* current arm position */
int confused; /* needs to be recalibrated */
int vers;

int tcyl; /* target cylinder */
int thead; /* target head */
int tsec; /* target sector */
long len; /* size of xfer */

uchar *cache; /* track cache */
int ccyl;
int chead;

Rendez r; /* waiting here for motor to spin up */
};

/*
* controller for 4 floppys
*/
struct FController
{
QLock; /* exclusive access to the contoller */

int ndrive;
FDrive *d; /* the floppy drives */
FDrive *selected;
int rate; /* current rate selected */
uchar cmd[14]; /* command */
int ncmd; /* # command bytes */
uchar stat[14]; /* command status */
int nstat; /* # status bytes */
int confused; /* controler needs to be reset */
Rendez r; /* wait here for command termination */
int motor; /* bit mask of spinning disks */
Rendez kr; /* for motor watcher */
};

/*
* floppy types (all MFM encoding)
*/
struct FType
{
char *name;
int dt; /* compatible drive type */
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 */
int rate; /* rate code */

/*
* these depend on previous entries and are set filled in
* by floppyinit
*/
int bcode; /* coded version of bytes for the controller */
long cap; /* drive capacity in bytes */
long tsize; /* track size in bytes */
};
/* bits in the registers */
enum
{
/* status registers a & b */
Psra= 0x3f0,
Psrb= 0x3f1,

/* digital output register */
Pdor= 0x3f2,
Fintena= 0x8, /* enable floppy interrupt */
Fena= 0x4, /* 0 == reset controller */

/* main status register */
Pmsr= 0x3f4,
Fready= 0x80, /* ready to be touched */
Ffrom= 0x40, /* data from controller */
Ffloppybusy= 0x10, /* operation not over */

/* data register */
Pfdata= 0x3f5,
Frecal= 0x07, /* recalibrate cmd */
Fseek= 0x0f, /* seek cmd */
Fsense= 0x08, /* sense cmd */
Fread= 0x66, /* read cmd */
Freadid= 0x4a, /* read track id */
Fspec= 0x03, /* set hold times */
Fwrite= 0x45, /* write cmd */
Fformat= 0x4d, /* format cmd */
Fmulti= 0x80, /* or'd with Fread or Fwrite for multi-head */
Fdumpreg= 0x0e, /* dump internal registers */

/* digital input register */
Pdir= 0x3F7, /* disk changed port (read only) */
Pdsr= 0x3F7, /* data rate select port (write only) */
Fchange= 0x80, /* disk has changed */

/* status 0 byte */
Drivemask= 3<<0,
Seekend= 1<<5,
Codemask= (3<<6)|(3<<3),
Cmdexec= 1<<6,

/* status 1 byte */
Overrun= 0x10,
};

static void
pcfloppyintr(Ureg *ur, void *a)
{
USED(a);

floppyintr(ur);
}

void
floppysetup0(FController *fl)
{
fl->ndrive = 0;
if(ioalloc(Psra, 6, 0, "floppy") < 0)
return;
if(ioalloc(Pdir, 1, 0, "floppy") < 0){
iofree(Psra);
return;
}
fl->ndrive = 1;
}

void
floppysetup1(FController *fl)
{
if(fl->ndrive > 0){
fl->d[0].dt = 4;
floppysetdef(&fl->d[0]);
}
if(fl->ndrive > 1){
fl->d[1].dt = 4;
floppysetdef(&fl->d[1]);
}

intrenable(IrqFLOPPY, pcfloppyintr, fl, BUSUNKNOWN, "floppy");
}

/*
* eject disk
*/
void
floppyeject(FDrive *dp)
{
floppyon(dp);
dp->vers++;
floppyoff(dp);
}

int
floppyexec(char *a, long b, int c)
{
USED(a, b, c);
return b;
}