/*
* check if the floppy has been replaced under foot. cause
* an error if it has.
*
* a seek and a read clears the condition. this was determined
* experimentally, there has to be a better way.
*
* if the read fails, cycle through the possible floppy
* density till one works or we've cycled through all
* possibilities for this drive.
*/
static void
changed(Chan *c, FDrive *dp)
{
ulong old;
FType *start;
/*
* if floppy has changed or first time through
*/
if((inb(Pdir)&Fchange) || dp->vers == 0){
DPRINT("changed\n");
fldump();
dp->vers++;
start = dp->t;
dp->maxtries = 3; /* limit it when we're probing */
/* floppyon will fail if there's a controller but no drive */
dp->confused = 1; /* make floppyon recal */
if(floppyon(dp) < 0)
error(Eio);
/* seek to the first track */
floppyseek(dp, dp->t->heads*dp->t->tsize);
while(waserror()){
/*
* if first attempt doesn't reset changed bit, there's
* no floppy there
*/
if(inb(Pdir)&Fchange)
nexterror();
while(++dp->t){
if(dp->t == &floppytype[nelem(floppytype)])
dp->t = floppytype;
if(dp->dt == dp->t->dt)
break;
}
floppydir[1+NFDIR*dp->dev].length = dp->t->cap;
/* floppyon will fail if there's a controller but no drive */
if(floppyon(dp) < 0)
error(Eio);
DPRINT("changed: trying %s\n", dp->t->name);
fldump();
if(dp->t == start)
nexterror();
}
/* if the read succeeds, we've got the density right */
floppyxfer(dp, Fread, dp->cache, 0, dp->t->tsize);
poperror();
dp->maxtries = 20;
}
old = c->qid.vers;
c->qid.vers = dp->vers;
if(old && old != dp->vers)
error(Eio);
}
/*
* check if the floppy has been replaced under foot. cause
* an error if it has.
*
* a seek and a read clears the condition. this was determined
* experimentally, there has to be a better way.
*
* if the read fails, cycle through the possible floppy
* density till one works or we've cycled through all
* possibilities for this drive.
*/
static int
changed(FDrive *dp)
{
FType *start;
/*
* if floppy has changed or first time through
*/
if((inb(Pdir)&Fchange) || dp->vers == 0) {
DPRINT("changed\n");
fldump();
dp->vers++;
floppysetdef(dp);
dp->maxtries = 3;
start = dp->t;
/* flopppyon fails if there's no drive */
dp->confused = 1; /* make floppyon recal */
if(floppyon(dp) < 0)
return -1;
pcfloppyseek(dp, dp->t->heads*dp->t->tsize);
while(floppyxfer(dp, Fread, dp->cache, 0, dp->t->tsize) <= 0) {
/*
* if the xfer attempt doesn't clear the changed bit,
* there's no floppy in the drive
*/
if(inb(Pdir)&Fchange)
return -1;
while(++dp->t) {
if(dp->t == &floppytype[nelem(floppytype)])
dp->t = floppytype;
if(dp->dt == dp->t->dt)
break;
}
/* flopppyon fails if there's no drive */
if(floppyon(dp) < 0)
return -1;
DPRINT("changed: trying %s\n", dp->t->name);
fldump();
if(dp->t == start)
return -1;
}
}
return 0;
}
/*
* get a command result from the floppy
*
* when the controller goes ready waiting for a command
* (instead of sending results), we're done
*
*/
static int
floppyresult(void)
{
int i, s;
int tries;
/* get the result of the operation */
for(i = 0; i < sizeof(fl.stat); i++) {
/* wait for status byte */
for(tries = 0; ; tries++) {
s = inb(Pmsr)&(Ffrom|Fready);
if(s == Fready) {
fl.nstat = i;
return fl.nstat;
}
if(s == (Ffrom|Fready))
break;
if(tries > 1000) {
DPRINT("floppyresult: %d stats\n", i);
fldump();
fl.confused = 1;
return -1;
}
microdelay(1);
}
fl.stat[i] = inb(Pfdata);
}
fl.nstat = sizeof(fl.stat);
return fl.nstat;
}
/*
* send a command to the floppy
*/
static int
floppycmd(void)
{
int i;
int tries;
fl.nstat = 0;
for(i = 0; i < fl.ncmd; i++) {
for(tries = 0; ; tries++) {
if((inb(Pmsr)&(Ffrom|Fready)) == Fready)
break;
if(tries > 1000) {
DPRINT("cmd %ux can't be sent (%d)\n", fl.cmd[0], i);
fldump();
/* empty fifo, might have been a bad command */
floppyresult();
return -1;
}
microdelay(1);
}
outb(Pfdata, fl.cmd[i]);
}
return 0;
}
/*
* if the controller or a specific drive is in a confused state,
* reset it and get back to a kown state
*/
static void
floppyrevive(void)
{
FDrive *dp;
/*
* reset the controller if it's confused
*/
if(fl.confused) {
DPRINT("floppyrevive in\n");
fldump();
/* reset controller and turn all motors off */
splhi();
fl.ncmd = 1;
fl.cmd[0] = 0;
outb(Pdor, 0);
delay(10);
outb(Pdor, Fintena|Fena);
delay(10);
spllo();
fl.motor = 0;
fl.confused = 0;
floppywait(0);
/* mark all drives in an unknown state */
for(dp = fl.d; dp < &fl.d[fl.ndrive]; dp++)
dp->confused = 1;
/* set rate to a known value */
outb(Pdsr, 0);
fl.rate = 0;
DPRINT("floppyrevive out\n");
fldump();
}
}
/*
* get the interrupt cause from the floppy.
*/
static int
floppysense(void)
{
fl.ncmd = 0;
fl.cmd[fl.ncmd++] = Fsense;
if(floppycmd() < 0)
return -1;
if(floppyresult() < 2) {
DPRINT("can't read sense response\n");
fldump();
fl.confused = 1;
return -1;
}
return 0;
}
