/*
   * Driver for the SWIM3 (Super Woz Integrated Machine 3)
   * floppy controller found on Power Macintoshes.
   *
   * Copyright (C) 1996 Paul Mackerras.
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * as published by the Free Software Foundation; either version
   * 2 of the License, or (at your option) any later version.
   */
  
  /*
   * TODO:
   * handle 2 drives
   * handle GCR disks
   */

  #undef DEBUG

  #include <linux/stddef.h>
  #include <linux/kernel.h>

  #include <linux/sched/signal.h>

  #include <linux/timer.h>
  #include <linux/delay.h>
  #include <linux/fd.h>
  #include <linux/ioctl.h>
  #include <linux/blkdev.h>

  #include <linux/interrupt.h>

  #include <linux/mutex.h>

  #include <linux/module.h>

  #include <linux/spinlock.h>

  #include <linux/wait.h>

  #include <asm/io.h>
  #include <asm/dbdma.h>
  #include <asm/prom.h>

  #include <linux/uaccess.h>

  #include <asm/mediabay.h>
  #include <asm/machdep.h>
  #include <asm/pmac_feature.h>

  #define MAX_FLOPPIES	2

  static DEFINE_MUTEX(swim3_mutex);
  static struct gendisk *disks[MAX_FLOPPIES];

  enum swim_state {
  	idle,
  	locating,
  	seeking,
  	settling,
  	do_transfer,
  	jogging,
  	available,
  	revalidating,
  	ejecting
  };
  
  #define REG(x)	unsigned char x; char x ## _pad[15];
  
  /*
   * The names for these registers mostly represent speculation on my part.
   * It will be interesting to see how close they are to the names Apple uses.
   */
  struct swim3 {
  	REG(data);
  	REG(timer);		/* counts down at 1MHz */
  	REG(error);
  	REG(mode);
  	REG(select);		/* controls CA0, CA1, CA2 and LSTRB signals */
  	REG(setup);
  	REG(control);		/* writing bits clears them */
  	REG(status);		/* writing bits sets them in control */
  	REG(intr);
  	REG(nseek);		/* # tracks to seek */
  	REG(ctrack);		/* current track number */
  	REG(csect);		/* current sector number */
  	REG(gap3);		/* size of gap 3 in track format */
  	REG(sector);		/* sector # to read or write */
  	REG(nsect);		/* # sectors to read or write */
  	REG(intr_enable);
  };
  
  #define control_bic	control
  #define control_bis	status
  
  /* Bits in select register */
  #define CA_MASK		7
  #define LSTRB		8
  
  /* Bits in control register */
  #define DO_SEEK		0x80
  #define FORMAT		0x40
  #define SELECT		0x20
  #define WRITE_SECTORS	0x10
  #define DO_ACTION	0x08
  #define DRIVE2_ENABLE	0x04
  #define DRIVE_ENABLE	0x02
  #define INTR_ENABLE	0x01
  
  /* Bits in status register */
  #define FIFO_1BYTE	0x80
  #define FIFO_2BYTE	0x40
  #define ERROR		0x20
  #define DATA		0x08
  #define RDDATA		0x04
  #define INTR_PENDING	0x02
  #define MARK_BYTE	0x01
  
  /* Bits in intr and intr_enable registers */
  #define ERROR_INTR	0x20
  #define DATA_CHANGED	0x10
  #define TRANSFER_DONE	0x08
  #define SEEN_SECTOR	0x04
  #define SEEK_DONE	0x02
  #define TIMER_DONE	0x01
  
  /* Bits in error register */
  #define ERR_DATA_CRC	0x80
  #define ERR_ADDR_CRC	0x40
  #define ERR_OVERRUN	0x04
  #define ERR_UNDERRUN	0x01
  
  /* Bits in setup register */
  #define S_SW_RESET	0x80
  #define S_GCR_WRITE	0x40
  #define S_IBM_DRIVE	0x20
  #define S_TEST_MODE	0x10
  #define S_FCLK_DIV2	0x08
  #define S_GCR		0x04
  #define S_COPY_PROT	0x02
  #define S_INV_WDATA	0x01
  
  /* Select values for swim3_action */
  #define SEEK_POSITIVE	0
  #define SEEK_NEGATIVE	4
  #define STEP		1
  #define MOTOR_ON	2
  #define MOTOR_OFF	6
  #define INDEX		3
  #define EJECT		7
  #define SETMFM		9
  #define SETGCR		13
  
  /* Select values for swim3_select and swim3_readbit */
  #define STEP_DIR	0
  #define STEPPING	1
  #define MOTOR_ON	2
  #define RELAX		3	/* also eject in progress */
  #define READ_DATA_0	4
  #define TWOMEG_DRIVE	5
  #define SINGLE_SIDED	6	/* drive or diskette is 4MB type? */
  #define DRIVE_PRESENT	7
  #define DISK_IN		8
  #define WRITE_PROT	9
  #define TRACK_ZERO	10
  #define TACHO		11
  #define READ_DATA_1	12
  #define MFM_MODE	13
  #define SEEK_COMPLETE	14
  #define ONEMEG_MEDIA	15
  
  /* Definitions of values used in writing and formatting */
  #define DATA_ESCAPE	0x99
  #define GCR_SYNC_EXC	0x3f
  #define GCR_SYNC_CONV	0x80
  #define GCR_FIRST_MARK	0xd5
  #define GCR_SECOND_MARK	0xaa
  #define GCR_ADDR_MARK	"\xd5\xaa\x00"
  #define GCR_DATA_MARK	"\xd5\xaa\x0b"
  #define GCR_SLIP_BYTE	"\x27\xaa"
  #define GCR_SELF_SYNC	"\x3f\xbf\x1e\x34\x3c\x3f"
  
  #define DATA_99		"\x99\x99"
  #define MFM_ADDR_MARK	"\x99\xa1\x99\xa1\x99\xa1\x99\xfe"
  #define MFM_INDEX_MARK	"\x99\xc2\x99\xc2\x99\xc2\x99\xfc"
  #define MFM_GAP_LEN	12
  
  struct floppy_state {
  	enum swim_state	state;
  	struct swim3 __iomem *swim3;	/* hardware registers */
  	struct dbdma_regs __iomem *dma;	/* DMA controller registers */
  	int	swim3_intr;	/* interrupt number for SWIM3 */
  	int	dma_intr;	/* interrupt number for DMA channel */
  	int	cur_cyl;	/* cylinder head is on, or -1 */
  	int	cur_sector;	/* last sector we saw go past */
  	int	req_cyl;	/* the cylinder for the current r/w request */
  	int	head;		/* head number ditto */
  	int	req_sector;	/* sector number ditto */
  	int	scount;		/* # sectors we're transferring at present */
  	int	retries;
  	int	settle_time;
  	int	secpercyl;	/* disk geometry information */
  	int	secpertrack;
  	int	total_secs;
  	int	write_prot;	/* 1 if write-protected, 0 if not, -1 dunno */
  	struct dbdma_cmd *dma_cmd;
  	int	ref_count;
  	int	expect_cyl;
  	struct timer_list timeout;
  	int	timeout_pending;
  	int	ejected;
  	wait_queue_head_t wait;
  	int	wanted;

  	struct macio_dev *mdev;

  	char	dbdma_cmd_space[5 * sizeof(struct dbdma_cmd)];

  	int	index;
  	struct request *cur_req;

  };

  #define swim3_err(fmt, arg...)	dev_err(&fs->mdev->ofdev.dev, "[fd%d] " fmt, fs->index, arg)
  #define swim3_warn(fmt, arg...)	dev_warn(&fs->mdev->ofdev.dev, "[fd%d] " fmt, fs->index, arg)
  #define swim3_info(fmt, arg...)	dev_info(&fs->mdev->ofdev.dev, "[fd%d] " fmt, fs->index, arg)
  
  #ifdef DEBUG
  #define swim3_dbg(fmt, arg...)	dev_dbg(&fs->mdev->ofdev.dev, "[fd%d] " fmt, fs->index, arg)
  #else
  #define swim3_dbg(fmt, arg...)	do { } while(0)
  #endif

  static struct floppy_state floppy_states[MAX_FLOPPIES];
  static int floppy_count = 0;
  static DEFINE_SPINLOCK(swim3_lock);
  
  static unsigned short write_preamble[] = {
  	0x4e4e, 0x4e4e, 0x4e4e, 0x4e4e, 0x4e4e,	/* gap field */
  	0, 0, 0, 0, 0, 0,			/* sync field */
  	0x99a1, 0x99a1, 0x99a1, 0x99fb,		/* data address mark */
  	0x990f					/* no escape for 512 bytes */
  };
  
  static unsigned short write_postamble[] = {
  	0x9904,					/* insert CRC */
  	0x4e4e, 0x4e4e,
  	0x9908,					/* stop writing */
  	0, 0, 0, 0, 0, 0
  };

  static void seek_track(struct floppy_state *fs, int n);
  static void init_dma(struct dbdma_cmd *cp, int cmd, void *buf, int count);

  static void act(struct floppy_state *fs);
  static void scan_timeout(unsigned long data);
  static void seek_timeout(unsigned long data);
  static void settle_timeout(unsigned long data);
  static void xfer_timeout(unsigned long data);

  static irqreturn_t swim3_interrupt(int irq, void *dev_id);
  /*static void fd_dma_interrupt(int irq, void *dev_id);*/

  static int grab_drive(struct floppy_state *fs, enum swim_state state,
  		      int interruptible);
  static void release_drive(struct floppy_state *fs);
  static int fd_eject(struct floppy_state *fs);

  static int floppy_ioctl(struct block_device *bdev, fmode_t mode,

  			unsigned int cmd, unsigned long param);

  static int floppy_open(struct block_device *bdev, fmode_t mode);

  static void floppy_release(struct gendisk *disk, fmode_t mode);

  static unsigned int floppy_check_events(struct gendisk *disk,
  					unsigned int clearing);

  static int floppy_revalidate(struct gendisk *disk);

  static bool swim3_end_request(struct floppy_state *fs, int err, unsigned int nr_bytes)

  {

  	struct request *req = fs->cur_req;
  	int rc;

  	swim3_dbg("  end request, err=%d nr_bytes=%d, cur_req=%p
  ",
  		  err, nr_bytes, req);

  	if (err)
  		nr_bytes = blk_rq_cur_bytes(req);
  	rc = __blk_end_request(req, err, nr_bytes);
  	if (rc)
  		return true;
  	fs->cur_req = NULL;
  	return false;

  }

  static void swim3_select(struct floppy_state *fs, int sel)
  {
  	struct swim3 __iomem *sw = fs->swim3;
  
  	out_8(&sw->select, RELAX);
  	if (sel & 8)
  		out_8(&sw->control_bis, SELECT);
  	else
  		out_8(&sw->control_bic, SELECT);
  	out_8(&sw->select, sel & CA_MASK);
  }
  
  static void swim3_action(struct floppy_state *fs, int action)
  {
  	struct swim3 __iomem *sw = fs->swim3;
  
  	swim3_select(fs, action);
  	udelay(1);
  	out_8(&sw->select, sw->select | LSTRB);
  	udelay(2);
  	out_8(&sw->select, sw->select & ~LSTRB);
  	udelay(1);
  }
  
  static int swim3_readbit(struct floppy_state *fs, int bit)
  {
  	struct swim3 __iomem *sw = fs->swim3;
  	int stat;
  
  	swim3_select(fs, bit);
  	udelay(1);
  	stat = in_8(&sw->status);
  	return (stat & DATA) == 0;
  }

  static void start_request(struct floppy_state *fs)
  {
  	struct request *req;
  	unsigned long x;

  	swim3_dbg("start request, initial state=%d
  ", fs->state);

  	if (fs->state == idle && fs->wanted) {
  		fs->state = available;
  		wake_up(&fs->wait);
  		return;
  	}

  	while (fs->state == idle) {

  		swim3_dbg("start request, idle loop, cur_req=%p
  ", fs->cur_req);
  		if (!fs->cur_req) {
  			fs->cur_req = blk_fetch_request(disks[fs->index]->queue);
  			swim3_dbg("  fetched request %p
  ", fs->cur_req);
  			if (!fs->cur_req)

  				break;

  		}

  		req = fs->cur_req;
  
  		if (fs->mdev->media_bay &&
  		    check_media_bay(fs->mdev->media_bay) != MB_FD) {
  			swim3_dbg("%s", "  media bay absent, dropping req
  ");
  			swim3_end_request(fs, -ENODEV, 0);
  			continue;
  		}
  
  #if 0 /* This is really too verbose */
  		swim3_dbg("do_fd_req: dev=%s cmd=%d sec=%ld nr_sec=%u buf=%p
  ",
  			  req->rq_disk->disk_name, req->cmd,
  			  (long)blk_rq_pos(req), blk_rq_sectors(req),

  			  bio_data(req->bio));

  		swim3_dbg("           current_nr_sectors=%u
  ",
  			  blk_rq_cur_sectors(req));

  #endif

  		if (blk_rq_pos(req) >= fs->total_secs) {

  			swim3_dbg("  pos out of bounds (%ld, max is %ld)
  ",
  				  (long)blk_rq_pos(req), (long)fs->total_secs);
  			swim3_end_request(fs, -EIO, 0);

  			continue;
  		}

  		if (fs->ejected) {

  			swim3_dbg("%s", "  disk ejected
  ");
  			swim3_end_request(fs, -EIO, 0);

  			continue;
  		}
  
  		if (rq_data_dir(req) == WRITE) {
  			if (fs->write_prot < 0)
  				fs->write_prot = swim3_readbit(fs, WRITE_PROT);
  			if (fs->write_prot) {

  				swim3_dbg("%s", "  try to write, disk write protected
  ");
  				swim3_end_request(fs, -EIO, 0);

  				continue;
  			}
  		}

  		/* Do not remove the cast. blk_rq_pos(req) is now a
  		 * sector_t and can be 64 bits, but it will never go
  		 * past 32 bits for this driver anyway, so we can
  		 * safely cast it down and not have to do a 64/32
  		 * division

  		 */

  		fs->req_cyl = ((long)blk_rq_pos(req)) / fs->secpercyl;
  		x = ((long)blk_rq_pos(req)) % fs->secpercyl;

  		fs->head = x / fs->secpertrack;
  		fs->req_sector = x % fs->secpertrack + 1;

  		fs->state = do_transfer;
  		fs->retries = 0;
  
  		act(fs);
  	}
  }

  static void do_fd_request(struct request_queue * q)
  {
  	start_request(q->queuedata);
  }

  static void set_timeout(struct floppy_state *fs, int nticks,
  			void (*proc)(unsigned long))
  {

  	if (fs->timeout_pending)
  		del_timer(&fs->timeout);
  	fs->timeout.expires = jiffies + nticks;
  	fs->timeout.function = proc;
  	fs->timeout.data = (unsigned long) fs;
  	add_timer(&fs->timeout);
  	fs->timeout_pending = 1;

  }
  
  static inline void scan_track(struct floppy_state *fs)
  {
  	struct swim3 __iomem *sw = fs->swim3;
  
  	swim3_select(fs, READ_DATA_0);
  	in_8(&sw->intr);		/* clear SEEN_SECTOR bit */
  	in_8(&sw->error);
  	out_8(&sw->intr_enable, SEEN_SECTOR);
  	out_8(&sw->control_bis, DO_ACTION);
  	/* enable intr when track found */
  	set_timeout(fs, HZ, scan_timeout);	/* enable timeout */
  }
  
  static inline void seek_track(struct floppy_state *fs, int n)
  {
  	struct swim3 __iomem *sw = fs->swim3;
  
  	if (n >= 0) {
  		swim3_action(fs, SEEK_POSITIVE);
  		sw->nseek = n;
  	} else {
  		swim3_action(fs, SEEK_NEGATIVE);
  		sw->nseek = -n;
  	}
  	fs->expect_cyl = (fs->cur_cyl >= 0)? fs->cur_cyl + n: -1;
  	swim3_select(fs, STEP);
  	in_8(&sw->error);
  	/* enable intr when seek finished */
  	out_8(&sw->intr_enable, SEEK_DONE);
  	out_8(&sw->control_bis, DO_SEEK);
  	set_timeout(fs, 3*HZ, seek_timeout);	/* enable timeout */
  	fs->settle_time = 0;
  }
  
  static inline void init_dma(struct dbdma_cmd *cp, int cmd,
  			    void *buf, int count)
  {

  	cp->req_count = cpu_to_le16(count);
  	cp->command = cpu_to_le16(cmd);
  	cp->phy_addr = cpu_to_le32(virt_to_bus(buf));

  	cp->xfer_status = 0;
  }
  
  static inline void setup_transfer(struct floppy_state *fs)
  {
  	int n;
  	struct swim3 __iomem *sw = fs->swim3;
  	struct dbdma_cmd *cp = fs->dma_cmd;
  	struct dbdma_regs __iomem *dr = fs->dma;

  	struct request *req = fs->cur_req;

  	if (blk_rq_cur_sectors(req) <= 0) {
  		swim3_warn("%s", "Transfer 0 sectors ?
  ");

  		return;
  	}

  	if (rq_data_dir(req) == WRITE)

  		n = 1;
  	else {
  		n = fs->secpertrack - fs->req_sector + 1;

  		if (n > blk_rq_cur_sectors(req))
  			n = blk_rq_cur_sectors(req);

  	}

  
  	swim3_dbg("  setup xfer at sect %d (of %d) head %d for %d
  ",
  		  fs->req_sector, fs->secpertrack, fs->head, n);

  	fs->scount = n;
  	swim3_select(fs, fs->head? READ_DATA_1: READ_DATA_0);
  	out_8(&sw->sector, fs->req_sector);
  	out_8(&sw->nsect, n);
  	out_8(&sw->gap3, 0);
  	out_le32(&dr->cmdptr, virt_to_bus(cp));

  	if (rq_data_dir(req) == WRITE) {

  		/* Set up 3 dma commands: write preamble, data, postamble */
  		init_dma(cp, OUTPUT_MORE, write_preamble, sizeof(write_preamble));
  		++cp;

  		init_dma(cp, OUTPUT_MORE, bio_data(req->bio), 512);

  		++cp;
  		init_dma(cp, OUTPUT_LAST, write_postamble, sizeof(write_postamble));
  	} else {

  		init_dma(cp, INPUT_LAST, bio_data(req->bio), n * 512);

  	}
  	++cp;
  	out_le16(&cp->command, DBDMA_STOP);
  	out_8(&sw->control_bic, DO_ACTION | WRITE_SECTORS);
  	in_8(&sw->error);
  	out_8(&sw->control_bic, DO_ACTION | WRITE_SECTORS);

  	if (rq_data_dir(req) == WRITE)

  		out_8(&sw->control_bis, WRITE_SECTORS);
  	in_8(&sw->intr);
  	out_le32(&dr->control, (RUN << 16) | RUN);
  	/* enable intr when transfer complete */
  	out_8(&sw->intr_enable, TRANSFER_DONE);
  	out_8(&sw->control_bis, DO_ACTION);
  	set_timeout(fs, 2*HZ, xfer_timeout);	/* enable timeout */
  }
  
  static void act(struct floppy_state *fs)
  {
  	for (;;) {

  		swim3_dbg("  act loop, state=%d, req_cyl=%d, cur_cyl=%d
  ",
  			  fs->state, fs->req_cyl, fs->cur_cyl);

  		switch (fs->state) {
  		case idle:
  			return;		/* XXX shouldn't get here */
  
  		case locating:
  			if (swim3_readbit(fs, TRACK_ZERO)) {

  				swim3_dbg("%s", "    locate track 0
  ");

  				fs->cur_cyl = 0;
  				if (fs->req_cyl == 0)
  					fs->state = do_transfer;
  				else
  					fs->state = seeking;
  				break;
  			}
  			scan_track(fs);
  			return;
  
  		case seeking:
  			if (fs->cur_cyl < 0) {
  				fs->expect_cyl = -1;
  				fs->state = locating;
  				break;
  			}
  			if (fs->req_cyl == fs->cur_cyl) {

  				swim3_warn("%s", "Whoops, seeking 0
  ");

  				fs->state = do_transfer;
  				break;
  			}
  			seek_track(fs, fs->req_cyl - fs->cur_cyl);
  			return;
  
  		case settling:
  			/* check for SEEK_COMPLETE after 30ms */
  			fs->settle_time = (HZ + 32) / 33;
  			set_timeout(fs, fs->settle_time, settle_timeout);
  			return;
  
  		case do_transfer:
  			if (fs->cur_cyl != fs->req_cyl) {
  				if (fs->retries > 5) {

  					swim3_err("Wrong cylinder in transfer, want: %d got %d
  ",
  						  fs->req_cyl, fs->cur_cyl);
  					swim3_end_request(fs, -EIO, 0);

  					fs->state = idle;
  					return;
  				}
  				fs->state = seeking;
  				break;
  			}
  			setup_transfer(fs);
  			return;
  
  		case jogging:
  			seek_track(fs, -5);
  			return;
  
  		default:

  			swim3_err("Unknown state %d
  ", fs->state);

  			return;
  		}
  	}
  }
  
  static void scan_timeout(unsigned long data)
  {
  	struct floppy_state *fs = (struct floppy_state *) data;
  	struct swim3 __iomem *sw = fs->swim3;

  	unsigned long flags;
  
  	swim3_dbg("* scan timeout, state=%d
  ", fs->state);

  	spin_lock_irqsave(&swim3_lock, flags);

  	fs->timeout_pending = 0;
  	out_8(&sw->control_bic, DO_ACTION | WRITE_SECTORS);
  	out_8(&sw->select, RELAX);
  	out_8(&sw->intr_enable, 0);
  	fs->cur_cyl = -1;
  	if (fs->retries > 5) {

  		swim3_end_request(fs, -EIO, 0);

  		fs->state = idle;
  		start_request(fs);
  	} else {
  		fs->state = jogging;
  		act(fs);
  	}

  	spin_unlock_irqrestore(&swim3_lock, flags);

  }
  
  static void seek_timeout(unsigned long data)
  {
  	struct floppy_state *fs = (struct floppy_state *) data;
  	struct swim3 __iomem *sw = fs->swim3;

  	unsigned long flags;
  
  	swim3_dbg("* seek timeout, state=%d
  ", fs->state);

  	spin_lock_irqsave(&swim3_lock, flags);

  	fs->timeout_pending = 0;
  	out_8(&sw->control_bic, DO_SEEK);
  	out_8(&sw->select, RELAX);
  	out_8(&sw->intr_enable, 0);

  	swim3_err("%s", "Seek timeout
  ");
  	swim3_end_request(fs, -EIO, 0);

  	fs->state = idle;
  	start_request(fs);

  	spin_unlock_irqrestore(&swim3_lock, flags);

  }
  
  static void settle_timeout(unsigned long data)
  {
  	struct floppy_state *fs = (struct floppy_state *) data;
  	struct swim3 __iomem *sw = fs->swim3;

  	unsigned long flags;
  
  	swim3_dbg("* settle timeout, state=%d
  ", fs->state);

  	spin_lock_irqsave(&swim3_lock, flags);

  	fs->timeout_pending = 0;
  	if (swim3_readbit(fs, SEEK_COMPLETE)) {
  		out_8(&sw->select, RELAX);
  		fs->state = locating;
  		act(fs);

  		goto unlock;

  	}
  	out_8(&sw->select, RELAX);
  	if (fs->settle_time < 2*HZ) {
  		++fs->settle_time;
  		set_timeout(fs, 1, settle_timeout);

  		goto unlock;

  	}

  	swim3_err("%s", "Seek settle timeout
  ");
  	swim3_end_request(fs, -EIO, 0);

  	fs->state = idle;
  	start_request(fs);

   unlock:
  	spin_unlock_irqrestore(&swim3_lock, flags);

  }
  
  static void xfer_timeout(unsigned long data)
  {
  	struct floppy_state *fs = (struct floppy_state *) data;
  	struct swim3 __iomem *sw = fs->swim3;
  	struct dbdma_regs __iomem *dr = fs->dma;

  	unsigned long flags;

  	int n;

  	swim3_dbg("* xfer timeout, state=%d
  ", fs->state);
  
  	spin_lock_irqsave(&swim3_lock, flags);

  	fs->timeout_pending = 0;
  	out_le32(&dr->control, RUN << 16);
  	/* We must wait a bit for dbdma to stop */
  	for (n = 0; (in_le32(&dr->status) & ACTIVE) && n < 1000; n++)
  		udelay(1);
  	out_8(&sw->intr_enable, 0);
  	out_8(&sw->control_bic, WRITE_SECTORS | DO_ACTION);
  	out_8(&sw->select, RELAX);

  	swim3_err("Timeout %sing sector %ld
  ",
  	       (rq_data_dir(fs->cur_req)==WRITE? "writ": "read"),
  	       (long)blk_rq_pos(fs->cur_req));
  	swim3_end_request(fs, -EIO, 0);

  	fs->state = idle;
  	start_request(fs);

  	spin_unlock_irqrestore(&swim3_lock, flags);

  }

  static irqreturn_t swim3_interrupt(int irq, void *dev_id)

  {
  	struct floppy_state *fs = (struct floppy_state *) dev_id;
  	struct swim3 __iomem *sw = fs->swim3;
  	int intr, err, n;
  	int stat, resid;
  	struct dbdma_regs __iomem *dr;
  	struct dbdma_cmd *cp;

  	unsigned long flags;
  	struct request *req = fs->cur_req;
  
  	swim3_dbg("* interrupt, state=%d
  ", fs->state);

  	spin_lock_irqsave(&swim3_lock, flags);

  	intr = in_8(&sw->intr);
  	err = (intr & ERROR_INTR)? in_8(&sw->error): 0;
  	if ((intr & ERROR_INTR) && fs->state != do_transfer)

  		swim3_err("Non-transfer error interrupt: state=%d, dir=%x, intr=%x, err=%x
  ",
  			  fs->state, rq_data_dir(req), intr, err);

  	switch (fs->state) {
  	case locating:
  		if (intr & SEEN_SECTOR) {
  			out_8(&sw->control_bic, DO_ACTION | WRITE_SECTORS);
  			out_8(&sw->select, RELAX);
  			out_8(&sw->intr_enable, 0);
  			del_timer(&fs->timeout);
  			fs->timeout_pending = 0;
  			if (sw->ctrack == 0xff) {

  				swim3_err("%s", "Seen sector but cyl=ff?
  ");

  				fs->cur_cyl = -1;
  				if (fs->retries > 5) {

  					swim3_end_request(fs, -EIO, 0);

  					fs->state = idle;
  					start_request(fs);
  				} else {
  					fs->state = jogging;
  					act(fs);
  				}
  				break;
  			}
  			fs->cur_cyl = sw->ctrack;
  			fs->cur_sector = sw->csect;
  			if (fs->expect_cyl != -1 && fs->expect_cyl != fs->cur_cyl)

  				swim3_err("Expected cyl %d, got %d
  ",
  					  fs->expect_cyl, fs->cur_cyl);

  			fs->state = do_transfer;
  			act(fs);
  		}
  		break;
  	case seeking:
  	case jogging:
  		if (sw->nseek == 0) {
  			out_8(&sw->control_bic, DO_SEEK);
  			out_8(&sw->select, RELAX);
  			out_8(&sw->intr_enable, 0);
  			del_timer(&fs->timeout);
  			fs->timeout_pending = 0;
  			if (fs->state == seeking)
  				++fs->retries;
  			fs->state = settling;
  			act(fs);
  		}
  		break;
  	case settling:
  		out_8(&sw->intr_enable, 0);
  		del_timer(&fs->timeout);
  		fs->timeout_pending = 0;
  		act(fs);
  		break;
  	case do_transfer:
  		if ((intr & (ERROR_INTR | TRANSFER_DONE)) == 0)
  			break;
  		out_8(&sw->intr_enable, 0);
  		out_8(&sw->control_bic, WRITE_SECTORS | DO_ACTION);
  		out_8(&sw->select, RELAX);
  		del_timer(&fs->timeout);
  		fs->timeout_pending = 0;
  		dr = fs->dma;
  		cp = fs->dma_cmd;

  		if (rq_data_dir(req) == WRITE)

  			++cp;
  		/*
  		 * Check that the main data transfer has finished.
  		 * On writing, the swim3 sometimes doesn't use
  		 * up all the bytes of the postamble, so we can still
  		 * see DMA active here.  That doesn't matter as long
  		 * as all the sector data has been transferred.
  		 */
  		if ((intr & ERROR_INTR) == 0 && cp->xfer_status == 0) {
  			/* wait a little while for DMA to complete */
  			for (n = 0; n < 100; ++n) {
  				if (cp->xfer_status != 0)
  					break;
  				udelay(1);
  				barrier();
  			}
  		}
  		/* turn off DMA */
  		out_le32(&dr->control, (RUN | PAUSE) << 16);

  		stat = le16_to_cpu(cp->xfer_status);
  		resid = le16_to_cpu(cp->res_count);

  		if (intr & ERROR_INTR) {
  			n = fs->scount - 1 - resid / 512;
  			if (n > 0) {

  				blk_update_request(req, 0, n << 9);

  				fs->req_sector += n;
  			}
  			if (fs->retries < 5) {
  				++fs->retries;
  				act(fs);
  			} else {

  				swim3_err("Error %sing block %ld (err=%x)
  ",
  				       rq_data_dir(req) == WRITE? "writ": "read",
  				       (long)blk_rq_pos(req), err);
  				swim3_end_request(fs, -EIO, 0);

  				fs->state = idle;
  			}
  		} else {
  			if ((stat & ACTIVE) == 0 || resid != 0) {
  				/* musta been an error */

  				swim3_err("fd dma error: stat=%x resid=%d
  ", stat, resid);
  				swim3_err("  state=%d, dir=%x, intr=%x, err=%x
  ",
  					  fs->state, rq_data_dir(req), intr, err);
  				swim3_end_request(fs, -EIO, 0);

  				fs->state = idle;
  				start_request(fs);
  				break;
  			}

  			fs->retries = 0;
  			if (swim3_end_request(fs, 0, fs->scount << 9)) {

  				fs->req_sector += fs->scount;
  				if (fs->req_sector > fs->secpertrack) {
  					fs->req_sector -= fs->secpertrack;
  					if (++fs->head > 1) {
  						fs->head = 0;
  						++fs->req_cyl;
  					}
  				}
  				act(fs);

  			} else
  				fs->state = idle;

  		}
  		if (fs->state == idle)
  			start_request(fs);
  		break;
  	default:

  		swim3_err("Don't know what to do in state %d
  ", fs->state);

  	}

  	spin_unlock_irqrestore(&swim3_lock, flags);

  	return IRQ_HANDLED;
  }
  
  /*

  static void fd_dma_interrupt(int irq, void *dev_id)

  {
  }
  */

  /* Called under the mutex to grab exclusive access to a drive */

  static int grab_drive(struct floppy_state *fs, enum swim_state state,
  		      int interruptible)
  {
  	unsigned long flags;

  	swim3_dbg("%s", "-> grab drive
  ");
  
  	spin_lock_irqsave(&swim3_lock, flags);
  	if (fs->state != idle && fs->state != available) {

  		++fs->wanted;

  		/* this will enable irqs in order to sleep */
  		if (!interruptible)
  			wait_event_lock_irq(fs->wait,
                                          fs->state == available,
                                          swim3_lock);
  		else if (wait_event_interruptible_lock_irq(fs->wait,
  					fs->state == available,
  					swim3_lock)) {
  			--fs->wanted;

  			spin_unlock_irqrestore(&swim3_lock, flags);

  			return -EINTR;

  		}
  		--fs->wanted;
  	}
  	fs->state = state;

  	spin_unlock_irqrestore(&swim3_lock, flags);

  	return 0;
  }
  
  static void release_drive(struct floppy_state *fs)
  {
  	unsigned long flags;

  	swim3_dbg("%s", "-> release drive
  ");
  
  	spin_lock_irqsave(&swim3_lock, flags);

  	fs->state = idle;
  	start_request(fs);

  	spin_unlock_irqrestore(&swim3_lock, flags);

  }
  
  static int fd_eject(struct floppy_state *fs)
  {
  	int err, n;
  
  	err = grab_drive(fs, ejecting, 1);
  	if (err)
  		return err;
  	swim3_action(fs, EJECT);
  	for (n = 20; n > 0; --n) {
  		if (signal_pending(current)) {
  			err = -EINTR;
  			break;
  		}
  		swim3_select(fs, RELAX);

  		schedule_timeout_interruptible(1);

  		if (swim3_readbit(fs, DISK_IN) == 0)
  			break;
  	}
  	swim3_select(fs, RELAX);
  	udelay(150);
  	fs->ejected = 1;
  	release_drive(fs);
  	return err;
  }
  
  static struct floppy_struct floppy_type =
  	{ 2880,18,2,80,0,0x1B,0x00,0xCF,0x6C,NULL };	/*  7 1.44MB 3.5"   */

  static int floppy_locked_ioctl(struct block_device *bdev, fmode_t mode,

  			unsigned int cmd, unsigned long param)
  {

  	struct floppy_state *fs = bdev->bd_disk->private_data;

  	int err;
  		
  	if ((cmd & 0x80) && !capable(CAP_SYS_ADMIN))
  		return -EPERM;

  	if (fs->mdev->media_bay &&
  	    check_media_bay(fs->mdev->media_bay) != MB_FD)

  		return -ENXIO;
  
  	switch (cmd) {
  	case FDEJECT:
  		if (fs->ref_count != 1)
  			return -EBUSY;
  		err = fd_eject(fs);
  		return err;
  	case FDGETPRM:
  	        if (copy_to_user((void __user *) param, &floppy_type,
  				 sizeof(struct floppy_struct)))
  			return -EFAULT;
  		return 0;
  	}
  	return -ENOTTY;
  }

  static int floppy_ioctl(struct block_device *bdev, fmode_t mode,
  				 unsigned int cmd, unsigned long param)
  {
  	int ret;

  	mutex_lock(&swim3_mutex);

  	ret = floppy_locked_ioctl(bdev, mode, cmd, param);

  	mutex_unlock(&swim3_mutex);

  
  	return ret;
  }

  static int floppy_open(struct block_device *bdev, fmode_t mode)

  {

  	struct floppy_state *fs = bdev->bd_disk->private_data;

  	struct swim3 __iomem *sw = fs->swim3;
  	int n, err = 0;
  
  	if (fs->ref_count == 0) {

  		if (fs->mdev->media_bay &&
  		    check_media_bay(fs->mdev->media_bay) != MB_FD)

  			return -ENXIO;
  		out_8(&sw->setup, S_IBM_DRIVE | S_FCLK_DIV2);
  		out_8(&sw->control_bic, 0xff);
  		out_8(&sw->mode, 0x95);
  		udelay(10);
  		out_8(&sw->intr_enable, 0);
  		out_8(&sw->control_bis, DRIVE_ENABLE | INTR_ENABLE);
  		swim3_action(fs, MOTOR_ON);
  		fs->write_prot = -1;
  		fs->cur_cyl = -1;
  		for (n = 0; n < 2 * HZ; ++n) {
  			if (n >= HZ/30 && swim3_readbit(fs, SEEK_COMPLETE))
  				break;
  			if (signal_pending(current)) {
  				err = -EINTR;
  				break;
  			}
  			swim3_select(fs, RELAX);

  			schedule_timeout_interruptible(1);

  		}
  		if (err == 0 && (swim3_readbit(fs, SEEK_COMPLETE) == 0
  				 || swim3_readbit(fs, DISK_IN) == 0))
  			err = -ENXIO;
  		swim3_action(fs, SETMFM);
  		swim3_select(fs, RELAX);

  	} else if (fs->ref_count == -1 || mode & FMODE_EXCL)

  		return -EBUSY;

  	if (err == 0 && (mode & FMODE_NDELAY) == 0
  	    && (mode & (FMODE_READ|FMODE_WRITE))) {
  		check_disk_change(bdev);

  		if (fs->ejected)
  			err = -ENXIO;
  	}

  	if (err == 0 && (mode & FMODE_WRITE)) {

  		if (fs->write_prot < 0)
  			fs->write_prot = swim3_readbit(fs, WRITE_PROT);
  		if (fs->write_prot)
  			err = -EROFS;
  	}
  
  	if (err) {
  		if (fs->ref_count == 0) {
  			swim3_action(fs, MOTOR_OFF);
  			out_8(&sw->control_bic, DRIVE_ENABLE | INTR_ENABLE);
  			swim3_select(fs, RELAX);
  		}
  		return err;
  	}

  	if (mode & FMODE_EXCL)

  		fs->ref_count = -1;
  	else
  		++fs->ref_count;
  
  	return 0;
  }

  static int floppy_unlocked_open(struct block_device *bdev, fmode_t mode)
  {
  	int ret;

  	mutex_lock(&swim3_mutex);

  	ret = floppy_open(bdev, mode);

  	mutex_unlock(&swim3_mutex);

  
  	return ret;
  }

  static void floppy_release(struct gendisk *disk, fmode_t mode)

  {

  	struct floppy_state *fs = disk->private_data;

  	struct swim3 __iomem *sw = fs->swim3;

  	mutex_lock(&swim3_mutex);

  	if (fs->ref_count > 0 && --fs->ref_count == 0) {
  		swim3_action(fs, MOTOR_OFF);
  		out_8(&sw->control_bic, 0xff);
  		swim3_select(fs, RELAX);
  	}

  	mutex_unlock(&swim3_mutex);

  }

  static unsigned int floppy_check_events(struct gendisk *disk,
  					unsigned int clearing)

  {
  	struct floppy_state *fs = disk->private_data;

  	return fs->ejected ? DISK_EVENT_MEDIA_CHANGE : 0;

  }
  
  static int floppy_revalidate(struct gendisk *disk)
  {
  	struct floppy_state *fs = disk->private_data;
  	struct swim3 __iomem *sw;
  	int ret, n;

  	if (fs->mdev->media_bay &&
  	    check_media_bay(fs->mdev->media_bay) != MB_FD)

  		return -ENXIO;
  
  	sw = fs->swim3;
  	grab_drive(fs, revalidating, 0);
  	out_8(&sw->intr_enable, 0);
  	out_8(&sw->control_bis, DRIVE_ENABLE);
  	swim3_action(fs, MOTOR_ON);	/* necessary? */
  	fs->write_prot = -1;
  	fs->cur_cyl = -1;
  	mdelay(1);
  	for (n = HZ; n > 0; --n) {
  		if (swim3_readbit(fs, SEEK_COMPLETE))
  			break;
  		if (signal_pending(current))
  			break;
  		swim3_select(fs, RELAX);

  		schedule_timeout_interruptible(1);

  	}
  	ret = swim3_readbit(fs, SEEK_COMPLETE) == 0
  		|| swim3_readbit(fs, DISK_IN) == 0;
  	if (ret)
  		swim3_action(fs, MOTOR_OFF);
  	else {
  		fs->ejected = 0;
  		swim3_action(fs, SETMFM);
  	}
  	swim3_select(fs, RELAX);
  
  	release_drive(fs);
  	return ret;
  }

  static const struct block_device_operations floppy_fops = {

  	.open		= floppy_unlocked_open,

  	.release	= floppy_release,

  	.ioctl		= floppy_ioctl,

  	.check_events	= floppy_check_events,

  	.revalidate_disk= floppy_revalidate,
  };

  static void swim3_mb_event(struct macio_dev* mdev, int mb_state)
  {
  	struct floppy_state *fs = macio_get_drvdata(mdev);

  	struct swim3 __iomem *sw;

  
  	if (!fs)
  		return;

  
  	sw = fs->swim3;

  	if (mb_state != MB_FD)
  		return;
  
  	/* Clear state */
  	out_8(&sw->intr_enable, 0);
  	in_8(&sw->intr);
  	in_8(&sw->error);
  }

  static int swim3_add_device(struct macio_dev *mdev, int index)

  {

  	struct device_node *swim = mdev->ofdev.dev.of_node;

  	struct floppy_state *fs = &floppy_states[index];
  	int rc = -EBUSY;

  	/* Do this first for message macros */
  	memset(fs, 0, sizeof(*fs));
  	fs->mdev = mdev;
  	fs->index = index;

  	/* Check & Request resources */
  	if (macio_resource_count(mdev) < 2) {

  		swim3_err("%s", "No address in device-tree
  ");

  		return -ENXIO;

  	}

  	if (macio_irq_count(mdev) < 1) {
  		swim3_err("%s", "No interrupt in device-tree
  ");
  		return -ENXIO;

  	}

  	if (macio_request_resource(mdev, 0, "swim3 (mmio)")) {

  		swim3_err("%s", "Can't request mmio resource
  ");

  		return -EBUSY;

  	}

  	if (macio_request_resource(mdev, 1, "swim3 (dma)")) {

  		swim3_err("%s", "Can't request dma resource
  ");

  		macio_release_resource(mdev, 0);
  		return -EBUSY;

  	}

  	dev_set_drvdata(&mdev->ofdev.dev, fs);

  	if (mdev->media_bay == NULL)

  		pmac_call_feature(PMAC_FTR_SWIM3_ENABLE, swim, 0, 1);
  	

  	fs->state = idle;

  	fs->swim3 = (struct swim3 __iomem *)
  		ioremap(macio_resource_start(mdev, 0), 0x200);
  	if (fs->swim3 == NULL) {

  		swim3_err("%s", "Couldn't map mmio registers
  ");

  		rc = -ENOMEM;
  		goto out_release;
  	}
  	fs->dma = (struct dbdma_regs __iomem *)
  		ioremap(macio_resource_start(mdev, 1), 0x200);
  	if (fs->dma == NULL) {

  		swim3_err("%s", "Couldn't map dma registers
  ");

  		iounmap(fs->swim3);
  		rc = -ENOMEM;
  		goto out_release;
  	}
  	fs->swim3_intr = macio_irq(mdev, 0);

  	fs->dma_intr = macio_irq(mdev, 1);

  	fs->cur_cyl = -1;
  	fs->cur_sector = -1;
  	fs->secpercyl = 36;
  	fs->secpertrack = 18;
  	fs->total_secs = 2880;

  	init_waitqueue_head(&fs->wait);
  
  	fs->dma_cmd = (struct dbdma_cmd *) DBDMA_ALIGN(fs->dbdma_cmd_space);
  	memset(fs->dma_cmd, 0, 2 * sizeof(struct dbdma_cmd));

  	fs->dma_cmd[1].command = cpu_to_le16(DBDMA_STOP);

  	if (mdev->media_bay == NULL || check_media_bay(mdev->media_bay) == MB_FD)
  		swim3_mb_event(mdev, MB_FD);

  	if (request_irq(fs->swim3_intr, swim3_interrupt, 0, "SWIM3", fs)) {

  		swim3_err("%s", "Couldn't request interrupt
  ");

  		pmac_call_feature(PMAC_FTR_SWIM3_ENABLE, swim, 0, 0);

  		goto out_unmap;

  		return -EBUSY;
  	}

  
  	init_timer(&fs->timeout);

  	swim3_info("SWIM3 floppy controller %s
  ",

  		mdev->media_bay ? "in media bay" : "");

  	return 0;
  
   out_unmap:
  	iounmap(fs->dma);
  	iounmap(fs->swim3);
  
   out_release:
  	macio_release_resource(mdev, 0);
  	macio_release_resource(mdev, 1);
  
  	return rc;
  }

  static int swim3_attach(struct macio_dev *mdev,
  			const struct of_device_id *match)

  {

  	struct gendisk *disk;

  	int index, rc;
  
  	index = floppy_count++;
  	if (index >= MAX_FLOPPIES)
  		return -ENXIO;

  
  	/* Add the drive */

  	rc = swim3_add_device(mdev, index);

  	if (rc)
  		return rc;

  	/* Now register that disk. Same comment about failure handling */
  	disk = disks[index] = alloc_disk(1);
  	if (disk == NULL)
  		return -ENOMEM;
  	disk->queue = blk_init_queue(do_fd_request, &swim3_lock);
  	if (disk->queue == NULL) {
  		put_disk(disk);
  		return -ENOMEM;
  	}
  	disk->queue->queuedata = &floppy_states[index];

  	if (index == 0) {

  		/* If we failed, there isn't much we can do as the driver is still
  		 * too dumb to remove the device, just bail out
  		 */
  		if (register_blkdev(FLOPPY_MAJOR, "fd"))
  			return 0;

  	}

  	disk->major = FLOPPY_MAJOR;

  	disk->first_minor = index;

  	disk->fops = &floppy_fops;

  	disk->private_data = &floppy_states[index];

  	disk->flags |= GENHD_FL_REMOVABLE;

  	sprintf(disk->disk_name, "fd%d", index);

  	set_capacity(disk, 2880);
  	add_disk(disk);
  
  	return 0;
  }
  
  static struct of_device_id swim3_match[] =
  {
  	{
  	.name		= "swim3",
  	},
  	{
  	.compatible	= "ohare-swim3"
  	},
  	{
  	.compatible	= "swim3"
  	},

  	{ /* end of list */ }

  };
  
  static struct macio_driver swim3_driver =
  {

  	.driver = {
  		.name 		= "swim3",
  		.of_match_table	= swim3_match,
  	},

  	.probe		= swim3_attach,

  #ifdef CONFIG_PMAC_MEDIABAY
  	.mediabay_event	= swim3_mb_event,
  #endif

  #if 0
  	.suspend	= swim3_suspend,
  	.resume		= swim3_resume,
  #endif
  };
  
  
  int swim3_init(void)
  {
  	macio_register_driver(&swim3_driver);

  	return 0;
  }
  
  module_init(swim3_init)
  
  MODULE_LICENSE("GPL");
  MODULE_AUTHOR("Paul Mackerras");
  MODULE_ALIAS_BLOCKDEV_MAJOR(FLOPPY_MAJOR);