ataflop.c

Linux块设备驱动源码

			if (minor2disktype[type].drive_types > DriveType)
				return -ENODEV;
			type = minor2disktype[type].index;
			dtp = &disk_type[type];
			if (UD.flags & FTD_MSG)
			    printk (KERN_ERR "floppy%d: found dtp %p name %s!\n",
			        drive, dtp, dtp->name);
		}
		else {
			if (!UDT)
				return -ENXIO;
			else
				dtp = UDT;
		}
		memset((void *)&getprm, 0, sizeof(getprm));
		getprm.size = dtp->blocks;
		getprm.sect = dtp->spt;
		getprm.head = 2;
		getprm.track = dtp->blocks/dtp->spt/2;
		getprm.stretch = dtp->stretch;
		if (copy_to_user((void *)param, &getprm, sizeof(getprm)))
			return -EFAULT;
		return 0;
	}
	switch (cmd) {
	case FDSETPRM:
	case FDDEFPRM:
	        /* 
		 * MSch 7/96: simple 'set geometry' case: just set the
		 * 'default' device params (minor == 0).
		 * Currently, the drive geometry is cleared after each
		 * disk change and subsequent revalidate()! simple
		 * implementation of FDDEFPRM: save geometry from a
		 * FDDEFPRM call and restore it in floppy_revalidate() !
		 */

		/* get the parameters from user space */
		if (floppy->ref != 1 && floppy->ref != -1)
			return -EBUSY;
		if (copy_from_user(&setprm, (void *) param, sizeof(setprm)))
			return -EFAULT;
		/* 
		 * first of all: check for floppy change and revalidate, 
		 * or the next access will revalidate - and clear UDT :-(
		 */

		if (check_floppy_change(disk))
		        floppy_revalidate(disk);

		if (UD.flags & FTD_MSG)
		    printk (KERN_INFO "floppy%d: setting size %d spt %d str %d!\n",
			drive, setprm.size, setprm.sect, setprm.stretch);

		/* what if type > 0 here? Overwrite specified entry ? */
		if (type) {
		        /* refuse to re-set a predefined type for now */
			redo_fd_request();
			return -EINVAL;
		}

		/* 
		 * type == 0: first look for a matching entry in the type list,
		 * and set the UD.disktype field to use the perdefined entry.
		 * TODO: add user-defined format to head of autoprobe list ? 
		 * Useful to include the user-type for future autodetection!
		 */

		for (settype = 0; settype < NUM_DISK_MINORS; settype++) {
			int setidx = 0;
			if (minor2disktype[settype].drive_types > DriveType) {
				/* skip this one, invalid for drive ... */
				continue;
			}
			setidx = minor2disktype[settype].index;
			dtp = &disk_type[setidx];

			/* found matching entry ?? */
			if (   dtp->blocks  == setprm.size 
			    && dtp->spt     == setprm.sect
			    && dtp->stretch == setprm.stretch ) {
				if (UD.flags & FTD_MSG)
				    printk (KERN_INFO "floppy%d: setting %s %p!\n",
				        drive, dtp->name, dtp);
				UDT = dtp;
				set_capacity(floppy->disk, UDT->blocks);

				if (cmd == FDDEFPRM) {
				  /* save settings as permanent default type */
				  default_params[drive].name    = dtp->name;
				  default_params[drive].spt     = dtp->spt;
				  default_params[drive].blocks  = dtp->blocks;
				  default_params[drive].fdc_speed = dtp->fdc_speed;
				  default_params[drive].stretch = dtp->stretch;
				}
				
				return 0;
			}

		}

		/* no matching disk type found above - setting user_params */

	       	if (cmd == FDDEFPRM) {
			/* set permanent type */
			dtp = &default_params[drive];
		} else
			/* set user type (reset by disk change!) */
			dtp = &user_params[drive];

		dtp->name   = "user format";
		dtp->blocks = setprm.size;
		dtp->spt    = setprm.sect;
		if (setprm.sect > 14) 
			dtp->fdc_speed = 3;
		else
			dtp->fdc_speed = 0;
		dtp->stretch = setprm.stretch;

		if (UD.flags & FTD_MSG)
			printk (KERN_INFO "floppy%d: blk %d spt %d str %d!\n",
				drive, dtp->blocks, dtp->spt, dtp->stretch);

		/* sanity check */
		if (!dtp || setprm.track != dtp->blocks/dtp->spt/2 ||
		    setprm.head != 2) {
			redo_fd_request();
			return -EINVAL;
		}

		UDT = dtp;
		set_capacity(floppy->disk, UDT->blocks);

		return 0;
	case FDMSGON:
		UD.flags |= FTD_MSG;
		return 0;
	case FDMSGOFF:
		UD.flags &= ~FTD_MSG;
		return 0;
	case FDSETEMSGTRESH:
		return -EINVAL;
	case FDFMTBEG:
		return 0;
	case FDFMTTRK:
		if (floppy->ref != 1 && floppy->ref != -1)
			return -EBUSY;
		if (copy_from_user(&fmt_desc, (void *) param, sizeof(fmt_desc)))
			return -EFAULT;
		return do_format(drive, type, &fmt_desc);
	case FDCLRPRM:
		UDT = NULL;
		/* MSch: invalidate default_params */
		default_params[drive].blocks  = 0;
		set_capacity(floppy->disk, MAX_DISK_SIZE * 2);
	case FDFMTEND:
	case FDFLUSH:
		/* invalidate the buffer track to force a reread */
		BufferDrive = -1;
		set_bit(drive, &fake_change);
		check_disk_change(inode->i_bdev);
		return 0;
	default:
		return -EINVAL;
	}
}


/* Initialize the 'unit' variable for drive 'drive' */

static void __init fd_probe( int drive )
{
	UD.connected = 0;
	UDT  = NULL;

	if (!fd_test_drive_present( drive ))
		return;

	UD.connected = 1;
	UD.track     = 0;
	switch( UserSteprate[drive] ) {
	case 2:
		UD.steprate = FDCSTEP_2;
		break;
	case 3:
		UD.steprate = FDCSTEP_3;
		break;
	case 6:
		UD.steprate = FDCSTEP_6;
		break;
	case 12:
		UD.steprate = FDCSTEP_12;
		break;
	default: /* should be -1 for "not set by user" */
		if (ATARIHW_PRESENT( FDCSPEED ) || MACH_IS_MEDUSA)
			UD.steprate = FDCSTEP_3;
		else
			UD.steprate = FDCSTEP_6;
		break;
	}
	MotorOn = 1;	/* from probe restore operation! */
}


/* This function tests the physical presence of a floppy drive (not
 * whether a disk is inserted). This is done by issuing a restore
 * command, waiting max. 2 seconds (that should be enough to move the
 * head across the whole disk) and looking at the state of the "TR00"
 * signal. This should now be raised if there is a drive connected
 * (and there is no hardware failure :-) Otherwise, the drive is
 * declared absent.
 */

static int __init fd_test_drive_present( int drive )
{
	unsigned long timeout;
	unsigned char status;
	int ok;
	
	if (drive >= (MACH_IS_FALCON ? 1 : 2)) return( 0 );
	fd_select_drive( drive );

	/* disable interrupt temporarily */
	atari_turnoff_irq( IRQ_MFP_FDC );
	FDC_WRITE (FDCREG_TRACK, 0xff00);
	FDC_WRITE( FDCREG_CMD, FDCCMD_RESTORE | FDCCMDADD_H | FDCSTEP_6 );

	timeout = jiffies + 2*HZ+HZ/2;
	while (time_before(jiffies, timeout))
		if (!(mfp.par_dt_reg & 0x20))
			break;

	status = FDC_READ( FDCREG_STATUS );
	ok = (status & FDCSTAT_TR00) != 0;

	/* force interrupt to abort restore operation (FDC would try
	 * about 50 seconds!) */
	FDC_WRITE( FDCREG_CMD, FDCCMD_FORCI );
	udelay(500);
	status = FDC_READ( FDCREG_STATUS );
	udelay(20);

	if (ok) {
		/* dummy seek command to make WP bit accessible */
		FDC_WRITE( FDCREG_DATA, 0 );
		FDC_WRITE( FDCREG_CMD, FDCCMD_SEEK );
		while( mfp.par_dt_reg & 0x20 )
			;
		status = FDC_READ( FDCREG_STATUS );
	}

	atari_turnon_irq( IRQ_MFP_FDC );
	return( ok );
}


/* Look how many and which kind of drives are connected. If there are
 * floppies, additionally start the disk-change and motor-off timers.
 */

static void __init config_types( void )
{
	int drive, cnt = 0;

	/* for probing drives, set the FDC speed to 8 MHz */
	if (ATARIHW_PRESENT(FDCSPEED))
		dma_wd.fdc_speed = 0;

	printk(KERN_INFO "Probing floppy drive(s):\n");
	for( drive = 0; drive < FD_MAX_UNITS; drive++ ) {
		fd_probe( drive );
		if (UD.connected) {
			printk(KERN_INFO "fd%d\n", drive);
			++cnt;
		}
	}

	if (FDC_READ( FDCREG_STATUS ) & FDCSTAT_BUSY) {
		/* If FDC is still busy from probing, give it another FORCI
		 * command to abort the operation. If this isn't done, the FDC
		 * will interrupt later and its IRQ line stays low, because
		 * the status register isn't read. And this will block any
		 * interrupts on this IRQ line :-(
		 */
		FDC_WRITE( FDCREG_CMD, FDCCMD_FORCI );
		udelay(500);
		FDC_READ( FDCREG_STATUS );
		udelay(20);
	}
	
	if (cnt > 0) {
		start_motor_off_timer();
		if (cnt == 1) fd_select_drive( 0 );
		start_check_change_timer();
	}
}

/*
 * floppy_open check for aliasing (/dev/fd0 can be the same as
 * /dev/PS0 etc), and disallows simultaneous access to the same
 * drive with different device numbers.
 */

static int floppy_open( struct inode *inode, struct file *filp )
{
	struct atari_floppy_struct *p = inode->i_bdev->bd_disk->private_data;
	int type  = iminor(inode) >> 2;

	DPRINT(("fd_open: type=%d\n",type));
	if (p->ref && p->type != type)
		return -EBUSY;

	if (p->ref == -1 || (p->ref && filp->f_flags & O_EXCL))
		return -EBUSY;

	if (filp->f_flags & O_EXCL)
		p->ref = -1;
	else
		p->ref++;

	p->type = type;

	if (filp->f_flags & O_NDELAY)
		return 0;

	if (filp->f_mode & 3) {
		check_disk_change(inode->i_bdev);
		if (filp->f_mode & 2) {
			if (p->wpstat) {
				if (p->ref < 0)
					p->ref = 0;
				else
					p->ref--;
				floppy_release(inode, filp);
				return -EROFS;
			}
		}
	}
	return 0;
}


static int floppy_release( struct inode * inode, struct file * filp )
{
	struct atari_floppy_struct *p = inode->i_bdev->bd_disk->private_data;
	if (p->ref < 0)
		p->ref = 0;
	else if (!p->ref--) {
		printk(KERN_ERR "floppy_release with fd_ref == 0");
		p->ref = 0;
	}
	return 0;
}

static struct block_device_operations floppy_fops = {
	.owner		= THIS_MODULE,
	.open		= floppy_open,
	.release	= floppy_release,
	.ioctl		= fd_ioctl,
	.media_changed	= check_floppy_change,
	.revalidate_disk= floppy_revalidate,
};

static struct kobject *floppy_find(dev_t dev, int *part, void *data)
{
	int drive = *part & 3;
	int type  = *part >> 2;
	if (drive >= FD_MAX_UNITS || type > NUM_DISK_MINORS)
		return NULL;
	*part = 0;
	return get_disk(unit[drive].disk);
}

static int __init atari_floppy_init (void)
{
	int i;

	if (!MACH_IS_ATARI)
		/* Amiga, Mac, ... don't have Atari-compatible floppy :-) */
		return -ENXIO;

	if (MACH_IS_HADES)
		/* Hades doesn't have Atari-compatible floppy */
		return -ENXIO;

	if (register_blkdev(FLOPPY_MAJOR,"fd"))
		return -EBUSY;

	for (i = 0; i < FD_MAX_UNITS; i++) {
		unit[i].disk = alloc_disk(1);
		if (!unit[i].disk)
			goto Enomem;
	}

	if (UseTrackbuffer < 0)
		/* not set by user -> use default: for now, we turn
		   track buffering off for all Medusas, though it
		   could be used with ones that have a counter
		   card. But the test is too hard :-( */
		UseTrackbuffer = !MACH_IS_MEDUSA;

	/* initialize variables */
	SelectedDrive = -1;
	BufferDrive = -1;

	DMABuffer = atari_stram_alloc(BUFFER_SIZE+512, "ataflop");
	if (!DMABuffer) {
		printk(KERN_ERR "atari_floppy_init: cannot get dma buffer\n");
		goto Enomem;
	}
	TrackBuffer = DMABuffer + 512;
	PhysDMABuffer = virt_to_phys(DMABuffer);
	PhysTrackBuffer = virt_to_phys(TrackBuffer);
	BufferDrive = BufferSide = BufferTrack = -1;

	floppy_queue = blk_init_queue(do_fd_request, &ataflop_lock);
	if (!floppy_queue)
		goto Enomem;

	for (i = 0; i < FD_MAX_UNITS; i++) {
		unit[i].track = -1;
		unit[i].flags = 0;
		unit[i].disk->major = FLOPPY_MAJOR;
		unit[i].disk->first_minor = i;
		sprintf(unit[i].disk->disk_name, "fd%d", i);
		unit[i].disk->fops = &floppy_fops;
		unit[i].disk->private_data = &unit[i];
		unit[i].disk->queue = floppy_queue;
		set_capacity(unit[i].disk, MAX_DISK_SIZE * 2);
		add_disk(unit[i].disk);
	}

	blk_register_region(MKDEV(FLOPPY_MAJOR, 0), 256, THIS_MODULE,
				floppy_find, NULL, NULL);

	printk(KERN_INFO "Atari floppy driver: max. %cD, %strack buffering\n",
	       DriveType == 0 ? 'D' : DriveType == 1 ? 'H' : 'E',
	       UseTrackbuffer ? "" : "no ");
	config_types();

	return 0;
Enomem:
	while (i--)
		put_disk(unit[i].disk);
	if (floppy_queue)
		blk_cleanup_queue(floppy_queue);
	unregister_blkdev(FLOPPY_MAJOR, "fd");
	return -ENOMEM;
}


void __init atari_floppy_setup( char *str, int *ints )
{
	int i;
	
	if (ints[0] < 1) {
		printk(KERN_ERR "ataflop_setup: no arguments!\n" );
		return;
	}
	else if (ints[0] > 2+FD_MAX_UNITS) {
		printk(KERN_ERR "ataflop_setup: too many arguments\n" );
	}

	if (ints[1] < 0 || ints[1] > 2)
		printk(KERN_ERR "ataflop_setup: bad drive type\n" );
	else
		DriveType = ints[1];

	if (ints[0] >= 2)
		UseTrackbuffer = (ints[2] > 0);

	for( i = 3; i <= ints[0] && i-3 < FD_MAX_UNITS; ++i ) {
		if (ints[i] != 2 && ints[i] != 3 && ints[i] != 6 && ints[i] != 12)
			printk(KERN_ERR "ataflop_setup: bad steprate\n" );
		else
			UserSteprate[i-3] = ints[i];
	}
}

static void atari_floppy_exit(void)
{
	int i;
	blk_unregister_region(MKDEV(FLOPPY_MAJOR, 0), 256);
	for (i = 0; i < FD_MAX_UNITS; i++) {
		del_gendisk(unit[i].disk);
		put_disk(unit[i].disk);
	}
	unregister_blkdev(FLOPPY_MAJOR, "fd");

	blk_cleanup_queue(floppy_queue);
	del_timer_sync(&fd_timer);
	atari_stram_free( DMABuffer );
}

module_init(atari_floppy_init)
module_exit(atari_floppy_exit)

MODULE_LICENSE("GPL");