/* -*- linux-c -*-
   *  drivers/cdrom/viocd.c
   *
   *  iSeries Virtual CD Rom
   *
   *  Authors: Dave Boutcher <boutcher@us.ibm.com>
   *           Ryan Arnold <ryanarn@us.ibm.com>
   *           Colin Devilbiss <devilbis@us.ibm.com>

   *           Stephen Rothwell

   *
   * (C) Copyright 2000-2004 IBM Corporation
   *
   * 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) anyu later version.
   *
   * This program is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   * General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software Foundation,
   * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
   *
   * This routine provides access to CD ROM drives owned and managed by an
   * OS/400 partition running on the same box as this Linux partition.
   *
   * All operations are performed by sending messages back and forth to
   * the OS/400 partition.
   */

  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

  #include <linux/major.h>
  #include <linux/blkdev.h>
  #include <linux/cdrom.h>
  #include <linux/errno.h>
  #include <linux/init.h>
  #include <linux/dma-mapping.h>
  #include <linux/module.h>
  #include <linux/completion.h>
  #include <linux/proc_fs.h>

  #include <linux/mutex.h>

  #include <linux/seq_file.h>

  #include <linux/scatterlist.h>

  #include <asm/vio.h>

  #include <asm/iseries/hv_types.h>

  #include <asm/iseries/hv_lp_event.h>

  #include <asm/iseries/vio.h>

  #include <asm/firmware.h>

  
  #define VIOCD_DEVICE			"iseries/vcd"

  
  #define VIOCD_VERS "1.06"

  /*
   * Should probably make this a module parameter....sigh
   */
  #define VIOCD_MAX_CD	HVMAXARCHITECTEDVIRTUALCDROMS

  static DEFINE_MUTEX(viocd_mutex);

  static const struct vio_error_entry viocd_err_table[] = {
  	{0x0201, EINVAL, "Invalid Range"},
  	{0x0202, EINVAL, "Invalid Token"},
  	{0x0203, EIO, "DMA Error"},
  	{0x0204, EIO, "Use Error"},
  	{0x0205, EIO, "Release Error"},
  	{0x0206, EINVAL, "Invalid CD"},
  	{0x020C, EROFS, "Read Only Device"},
  	{0x020D, ENOMEDIUM, "Changed or Missing Volume (or Varied Off?)"},
  	{0x020E, EIO, "Optical System Error (Varied Off?)"},
  	{0x02FF, EIO, "Internal Error"},
  	{0x3010, EIO, "Changed Volume"},
  	{0xC100, EIO, "Optical System Error"},
  	{0x0000, 0, NULL},
  };
  
  /*
   * This is the structure we use to exchange info between driver and interrupt
   * handler
   */
  struct viocd_waitevent {
  	struct completion	com;
  	int			rc;
  	u16			sub_result;
  	int			changed;
  };
  
  /* this is a lookup table for the true capabilities of a device */
  struct capability_entry {
  	char	*type;
  	int	capability;
  };
  
  static struct capability_entry capability_table[] __initdata = {
  	{ "6330", CDC_LOCK | CDC_DVD_RAM | CDC_RAM },
  	{ "6331", CDC_LOCK | CDC_DVD_RAM | CDC_RAM },
  	{ "6333", CDC_LOCK | CDC_DVD_RAM | CDC_RAM },
  	{ "632A", CDC_LOCK | CDC_DVD_RAM | CDC_RAM },
  	{ "6321", CDC_LOCK },
  	{ "632B", 0 },
  	{ NULL  , CDC_LOCK },
  };
  
  /* These are our internal structures for keeping track of devices */
  static int viocd_numdev;

  struct disk_info {
  	struct gendisk			*viocd_disk;
  	struct cdrom_device_info	viocd_info;
  	struct device			*dev;

  	const char			*rsrcname;
  	const char			*type;
  	const char			*model;

  };
  static struct disk_info viocd_diskinfo[VIOCD_MAX_CD];
  
  #define DEVICE_NR(di)	((di) - &viocd_diskinfo[0])
  
  static spinlock_t viocd_reqlock;
  
  #define MAX_CD_REQ	1
  
  /* procfs support */
  static int proc_viocd_show(struct seq_file *m, void *v)
  {
  	int i;
  
  	for (i = 0; i < viocd_numdev; i++) {
  		seq_printf(m, "viocd device %d is iSeries resource %10.10s"
  				"type %4.4s, model %3.3s
  ",

  				i, viocd_diskinfo[i].rsrcname,
  				viocd_diskinfo[i].type,
  				viocd_diskinfo[i].model);

  	}
  	return 0;
  }
  
  static int proc_viocd_open(struct inode *inode, struct file *file)
  {
  	return single_open(file, proc_viocd_show, NULL);
  }

  static const struct file_operations proc_viocd_operations = {

  	.owner		= THIS_MODULE,

  	.open		= proc_viocd_open,
  	.read		= seq_read,
  	.llseek		= seq_lseek,
  	.release	= single_release,
  };

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

  {

  	struct disk_info *di = bdev->bd_disk->private_data;

  	int ret;

  	mutex_lock(&viocd_mutex);

  	ret = cdrom_open(&di->viocd_info, bdev, mode);

  	mutex_unlock(&viocd_mutex);

  
  	return ret;

  }

  static int viocd_blk_release(struct gendisk *disk, fmode_t mode)

  {

  	struct disk_info *di = disk->private_data;

  	mutex_lock(&viocd_mutex);

  	cdrom_release(&di->viocd_info, mode);

  	mutex_unlock(&viocd_mutex);

  	return 0;

  }

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

  		unsigned cmd, unsigned long arg)
  {

  	struct disk_info *di = bdev->bd_disk->private_data;

  	int ret;

  	mutex_lock(&viocd_mutex);

  	ret = cdrom_ioctl(&di->viocd_info, bdev, mode, cmd, arg);

  	mutex_unlock(&viocd_mutex);

  
  	return ret;

  }

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

  {
  	struct disk_info *di = disk->private_data;

  	return cdrom_check_events(&di->viocd_info, clearing);

  }

  static const struct block_device_operations viocd_fops = {

  	.owner =		THIS_MODULE,

  	.open =			viocd_blk_open,
  	.release =		viocd_blk_release,

  	.ioctl =		viocd_blk_ioctl,

  	.check_events =		viocd_blk_check_events,

  };

  static int viocd_open(struct cdrom_device_info *cdi, int purpose)
  {
          struct disk_info *diskinfo = cdi->handle;
  	int device_no = DEVICE_NR(diskinfo);
  	HvLpEvent_Rc hvrc;
  	struct viocd_waitevent we;
  
  	init_completion(&we.com);
  	hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
  			HvLpEvent_Type_VirtualIo,
  			viomajorsubtype_cdio | viocdopen,
  			HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
  			viopath_sourceinst(viopath_hostLp),
  			viopath_targetinst(viopath_hostLp),
  			(u64)&we, VIOVERSION << 16, ((u64)device_no << 48),
  			0, 0, 0);
  	if (hvrc != 0) {

  		pr_warning("bad rc on HvCallEvent_signalLpEventFast %d
  ",
  			   (int)hvrc);

  		return -EIO;
  	}
  
  	wait_for_completion(&we.com);
  
  	if (we.rc) {
  		const struct vio_error_entry *err =
  			vio_lookup_rc(viocd_err_table, we.sub_result);

  		pr_warning("bad rc %d:0x%04X on open: %s
  ",
  			   we.rc, we.sub_result, err->msg);

  		return -err->errno;
  	}
  
  	return 0;
  }
  
  static void viocd_release(struct cdrom_device_info *cdi)
  {
  	int device_no = DEVICE_NR((struct disk_info *)cdi->handle);
  	HvLpEvent_Rc hvrc;
  
  	hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
  			HvLpEvent_Type_VirtualIo,
  			viomajorsubtype_cdio | viocdclose,
  			HvLpEvent_AckInd_NoAck, HvLpEvent_AckType_ImmediateAck,
  			viopath_sourceinst(viopath_hostLp),
  			viopath_targetinst(viopath_hostLp), 0,
  			VIOVERSION << 16, ((u64)device_no << 48), 0, 0, 0);
  	if (hvrc != 0)

  		pr_warning("bad rc on HvCallEvent_signalLpEventFast %d
  ",
  			   (int)hvrc);

  }
  
  /* Send a read or write request to OS/400 */
  static int send_request(struct request *req)
  {
  	HvLpEvent_Rc hvrc;
  	struct disk_info *diskinfo = req->rq_disk->private_data;
  	u64 len;
  	dma_addr_t dmaaddr;
  	int direction;
  	u16 cmd;
  	struct scatterlist sg;
  
  	BUG_ON(req->nr_phys_segments > 1);
  
  	if (rq_data_dir(req) == READ) {
  		direction = DMA_FROM_DEVICE;
  		cmd = viomajorsubtype_cdio | viocdread;
  	} else {
  		direction = DMA_TO_DEVICE;
  		cmd = viomajorsubtype_cdio | viocdwrite;
  	}

  	sg_init_table(&sg, 1);

          if (blk_rq_map_sg(req->q, req, &sg) == 0) {

  		pr_warning("error setting up scatter/gather list
  ");

  		return -1;
  	}
  
  	if (dma_map_sg(diskinfo->dev, &sg, 1, direction) == 0) {

  		pr_warning("error allocating sg tce
  ");

  		return -1;
  	}
  	dmaaddr = sg_dma_address(&sg);
  	len = sg_dma_len(&sg);
  
  	hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
  			HvLpEvent_Type_VirtualIo, cmd,
  			HvLpEvent_AckInd_DoAck,
  			HvLpEvent_AckType_ImmediateAck,
  			viopath_sourceinst(viopath_hostLp),
  			viopath_targetinst(viopath_hostLp),
  			(u64)req, VIOVERSION << 16,
  			((u64)DEVICE_NR(diskinfo) << 48) | dmaaddr,

  			(u64)blk_rq_pos(req) * 512, len, 0);

  	if (hvrc != HvLpEvent_Rc_Good) {

  		pr_warning("hv error on op %d
  ", (int)hvrc);

  		return -1;
  	}
  
  	return 0;
  }

  static int rwreq;

  static void do_viocd_request(struct request_queue *q)

  {
  	struct request *req;

  	while ((rwreq == 0) && ((req = blk_fetch_request(q)) != NULL)) {

  		if (req->cmd_type != REQ_TYPE_FS)

  			__blk_end_request_all(req, -EIO);

  		else if (send_request(req) < 0) {

  			pr_warning("unable to send message to OS/400!
  ");

  			__blk_end_request_all(req, -EIO);

  		} else
  			rwreq++;
  	}
  }

  static unsigned int viocd_check_events(struct cdrom_device_info *cdi,
  				       unsigned int clearing, int disc_nr)

  {
  	struct viocd_waitevent we;
  	HvLpEvent_Rc hvrc;
  	int device_no = DEVICE_NR((struct disk_info *)cdi->handle);
  
  	init_completion(&we.com);
  
  	/* Send the open event to OS/400 */
  	hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
  			HvLpEvent_Type_VirtualIo,
  			viomajorsubtype_cdio | viocdcheck,
  			HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
  			viopath_sourceinst(viopath_hostLp),
  			viopath_targetinst(viopath_hostLp),
  			(u64)&we, VIOVERSION << 16, ((u64)device_no << 48),
  			0, 0, 0);
  	if (hvrc != 0) {

  		pr_warning("bad rc on HvCallEvent_signalLpEventFast %d
  ",
  			   (int)hvrc);

  		return 0;

  	}
  
  	wait_for_completion(&we.com);
  
  	/* Check the return code.  If bad, assume no change */
  	if (we.rc) {
  		const struct vio_error_entry *err =
  			vio_lookup_rc(viocd_err_table, we.sub_result);

  		pr_warning("bad rc %d:0x%04X on check_change: %s; Assuming no change
  ",
  			   we.rc, we.sub_result, err->msg);

  		return 0;
  	}

  	return we.changed ? DISK_EVENT_MEDIA_CHANGE : 0;

  }
  
  static int viocd_lock_door(struct cdrom_device_info *cdi, int locking)
  {
  	HvLpEvent_Rc hvrc;
  	u64 device_no = DEVICE_NR((struct disk_info *)cdi->handle);
  	/* NOTE: flags is 1 or 0 so it won't overwrite the device_no */
  	u64 flags = !!locking;
  	struct viocd_waitevent we;
  
  	init_completion(&we.com);
  
  	/* Send the lockdoor event to OS/400 */
  	hvrc = HvCallEvent_signalLpEventFast(viopath_hostLp,
  			HvLpEvent_Type_VirtualIo,
  			viomajorsubtype_cdio | viocdlockdoor,
  			HvLpEvent_AckInd_DoAck, HvLpEvent_AckType_ImmediateAck,
  			viopath_sourceinst(viopath_hostLp),
  			viopath_targetinst(viopath_hostLp),
  			(u64)&we, VIOVERSION << 16,
  			(device_no << 48) | (flags << 32), 0, 0, 0);
  	if (hvrc != 0) {

  		pr_warning("bad rc on HvCallEvent_signalLpEventFast %d
  ",
  			   (int)hvrc);

  		return -EIO;
  	}
  
  	wait_for_completion(&we.com);
  
  	if (we.rc != 0)
  		return -EIO;
  	return 0;
  }
  
  static int viocd_packet(struct cdrom_device_info *cdi,
  		struct packet_command *cgc)
  {
  	unsigned int buflen = cgc->buflen;
  	int ret = -EIO;
  
  	switch (cgc->cmd[0]) {
  	case GPCMD_READ_DISC_INFO:
  		{
  			disc_information *di = (disc_information *)cgc->buffer;
  
  			if (buflen >= 2) {
  				di->disc_information_length = cpu_to_be16(1);
  				ret = 0;
  			}
  			if (buflen >= 3)
  				di->erasable =
  					(cdi->ops->capability & ~cdi->mask
  					 & (CDC_DVD_RAM | CDC_RAM)) != 0;
  		}
  		break;

  	case GPCMD_GET_CONFIGURATION:
  		if (cgc->cmd[3] == CDF_RWRT) {
  			struct rwrt_feature_desc *rfd = (struct rwrt_feature_desc *)(cgc->buffer + sizeof(struct feature_header));
  
  			if ((buflen >=
  			     (sizeof(struct feature_header) + sizeof(*rfd))) &&
  			    (cdi->ops->capability & ~cdi->mask
  			     & (CDC_DVD_RAM | CDC_RAM))) {
  				rfd->feature_code = cpu_to_be16(CDF_RWRT);
  				rfd->curr = 1;
  				ret = 0;
  			}
  		}
  		break;

  	default:
  		if (cgc->sense) {
  			/* indicate Unknown code */
  			cgc->sense->sense_key = 0x05;
  			cgc->sense->asc = 0x20;
  			cgc->sense->ascq = 0x00;
  		}
  		break;
  	}
  
  	cgc->stat = ret;
  	return ret;
  }
  
  static void restart_all_queues(int first_index)
  {
  	int i;
  
  	for (i = first_index + 1; i < viocd_numdev; i++)
  		if (viocd_diskinfo[i].viocd_disk)
  			blk_run_queue(viocd_diskinfo[i].viocd_disk->queue);
  	for (i = 0; i <= first_index; i++)
  		if (viocd_diskinfo[i].viocd_disk)
  			blk_run_queue(viocd_diskinfo[i].viocd_disk->queue);
  }
  
  /* This routine handles incoming CD LP events */
  static void vio_handle_cd_event(struct HvLpEvent *event)
  {
  	struct viocdlpevent *bevent;
  	struct viocd_waitevent *pwe;
  	struct disk_info *di;
  	unsigned long flags;
  	struct request *req;
  
  
  	if (event == NULL)
  		/* Notification that a partition went away! */
  		return;
  	/* First, we should NEVER get an int here...only acks */

  	if (hvlpevent_is_int(event)) {

  		pr_warning("Yikes! got an int in viocd event handler!
  ");

  		if (hvlpevent_need_ack(event)) {

  			event->xRc = HvLpEvent_Rc_InvalidSubtype;
  			HvCallEvent_ackLpEvent(event);
  		}
  	}
  
  	bevent = (struct viocdlpevent *)event;
  
  	switch (event->xSubtype & VIOMINOR_SUBTYPE_MASK) {
  	case viocdopen:
  		if (event->xRc == 0) {
  			di = &viocd_diskinfo[bevent->disk];

  			blk_queue_logical_block_size(di->viocd_disk->queue,
  						     bevent->block_size);

  			set_capacity(di->viocd_disk,
  					bevent->media_size *
  					bevent->block_size / 512);
  		}
  		/* FALLTHROUGH !! */

  	case viocdlockdoor:
  		pwe = (struct viocd_waitevent *)event->xCorrelationToken;
  return_complete:
  		pwe->rc = event->xRc;
  		pwe->sub_result = bevent->sub_result;
  		complete(&pwe->com);
  		break;
  
  	case viocdcheck:
  		pwe = (struct viocd_waitevent *)event->xCorrelationToken;
  		pwe->changed = bevent->flags;
  		goto return_complete;
  
  	case viocdclose:
  		break;
  
  	case viocdwrite:
  	case viocdread:
  		/*
  		 * Since this is running in interrupt mode, we need to
  		 * make sure we're not stepping on any global I/O operations
  		 */
  		di = &viocd_diskinfo[bevent->disk];
  		spin_lock_irqsave(&viocd_reqlock, flags);
  		dma_unmap_single(di->dev, bevent->token, bevent->len,
  				((event->xSubtype & VIOMINOR_SUBTYPE_MASK) == viocdread)
  				?  DMA_FROM_DEVICE : DMA_TO_DEVICE);
  		req = (struct request *)bevent->event.xCorrelationToken;
  		rwreq--;
  
  		if (event->xRc != HvLpEvent_Rc_Good) {
  			const struct vio_error_entry *err =
  				vio_lookup_rc(viocd_err_table,
  						bevent->sub_result);

  			pr_warning("request %p failed with rc %d:0x%04X: %s
  ",
  				   req, event->xRc,
  				   bevent->sub_result, err->msg);

  			__blk_end_request_all(req, -EIO);

  		} else

  			__blk_end_request_all(req, 0);

  
  		/* restart handling of incoming requests */
  		spin_unlock_irqrestore(&viocd_reqlock, flags);
  		restart_all_queues(bevent->disk);
  		break;
  
  	default:

  		pr_warning("message with invalid subtype %0x04X!
  ",
  			   event->xSubtype & VIOMINOR_SUBTYPE_MASK);

  		if (hvlpevent_need_ack(event)) {

  			event->xRc = HvLpEvent_Rc_InvalidSubtype;
  			HvCallEvent_ackLpEvent(event);
  		}
  	}
  }

  static int viocd_audio_ioctl(struct cdrom_device_info *cdi, unsigned int cmd,
  			     void *arg)
  {
  	return -EINVAL;
  }

  static struct cdrom_device_ops viocd_dops = {
  	.open = viocd_open,
  	.release = viocd_release,

  	.check_events = viocd_check_events,

  	.lock_door = viocd_lock_door,
  	.generic_packet = viocd_packet,

  	.audio_ioctl = viocd_audio_ioctl,

  	.capability = CDC_CLOSE_TRAY | CDC_OPEN_TRAY | CDC_LOCK | CDC_SELECT_SPEED | CDC_SELECT_DISC | CDC_MULTI_SESSION | CDC_MCN | CDC_MEDIA_CHANGED | CDC_PLAY_AUDIO | CDC_RESET | CDC_DRIVE_STATUS | CDC_GENERIC_PACKET | CDC_CD_R | CDC_CD_RW | CDC_DVD | CDC_DVD_R | CDC_DVD_RAM | CDC_RAM

  };

  static int find_capability(const char *type)

  {
  	struct capability_entry *entry;
  
  	for(entry = capability_table; entry->type; ++entry)
  		if(!strncmp(entry->type, type, 4))
  			break;
  	return entry->capability;
  }
  
  static int viocd_probe(struct vio_dev *vdev, const struct vio_device_id *id)
  {
  	struct gendisk *gendisk;
  	int deviceno;
  	struct disk_info *d;
  	struct cdrom_device_info *c;

  	struct request_queue *q;

  	struct device_node *node = vdev->dev.of_node;

  
  	deviceno = vdev->unit_address;

  	if (deviceno >= VIOCD_MAX_CD)

  		return -ENODEV;

  	if (!node)
  		return -ENODEV;
  
  	if (deviceno >= viocd_numdev)
  		viocd_numdev = deviceno + 1;

  
  	d = &viocd_diskinfo[deviceno];

  	d->rsrcname = of_get_property(node, "linux,vio_rsrcname", NULL);
  	d->type = of_get_property(node, "linux,vio_type", NULL);
  	d->model = of_get_property(node, "linux,vio_model", NULL);

  	c = &d->viocd_info;

  
  	c->ops = &viocd_dops;
  	c->speed = 4;
  	c->capacity = 1;
  	c->handle = d;

  	c->mask = ~find_capability(d->type);

  	sprintf(c->name, VIOCD_DEVICE "%c", 'a' + deviceno);
  
  	if (register_cdrom(c) != 0) {

  		pr_warning("Cannot register viocd CD-ROM %s!
  ", c->name);

  		goto out;
  	}

  	pr_info("cd %s is iSeries resource %10.10s type %4.4s, model %3.3s
  ",
  		c->name, d->rsrcname, d->type, d->model);

  	q = blk_init_queue(do_viocd_request, &viocd_reqlock);
  	if (q == NULL) {

  		pr_warning("Cannot allocate queue for %s!
  ", c->name);

  		goto out_unregister_cdrom;
  	}
  	gendisk = alloc_disk(1);
  	if (gendisk == NULL) {

  		pr_warning("Cannot create gendisk for %s!
  ", c->name);

  		goto out_cleanup_queue;
  	}
  	gendisk->major = VIOCD_MAJOR;
  	gendisk->first_minor = deviceno;
  	strncpy(gendisk->disk_name, c->name,
  			sizeof(gendisk->disk_name));

  	blk_queue_max_segments(q, 1);

  	blk_queue_max_hw_sectors(q, 4096 / 512);

  	gendisk->queue = q;
  	gendisk->fops = &viocd_fops;

  	gendisk->flags = GENHD_FL_CD | GENHD_FL_REMOVABLE |
  			 GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;

  	set_capacity(gendisk, 0);
  	gendisk->private_data = d;
  	d->viocd_disk = gendisk;
  	d->dev = &vdev->dev;
  	gendisk->driverfs_dev = d->dev;
  	add_disk(gendisk);
  	return 0;
  
  out_cleanup_queue:
  	blk_cleanup_queue(q);
  out_unregister_cdrom:
  	unregister_cdrom(c);
  out:
  	return -ENODEV;
  }
  
  static int viocd_remove(struct vio_dev *vdev)
  {
  	struct disk_info *d = &viocd_diskinfo[vdev->unit_address];

  	unregister_cdrom(&d->viocd_info);

  	del_gendisk(d->viocd_disk);
  	blk_cleanup_queue(d->viocd_disk->queue);
  	put_disk(d->viocd_disk);
  	return 0;
  }
  
  /**
   * viocd_device_table: Used by vio.c to match devices that we
   * support.
   */
  static struct vio_device_id viocd_device_table[] __devinitdata = {

  	{ "block", "IBM,iSeries-viocd" },

  	{ "", "" }

  };

  MODULE_DEVICE_TABLE(vio, viocd_device_table);

  static struct vio_driver viocd_driver = {

  	.id_table = viocd_device_table,
  	.probe = viocd_probe,

  	.remove = viocd_remove,
  	.driver = {
  		.name = "viocd",

  		.owner = THIS_MODULE,

  	}

  };
  
  static int __init viocd_init(void)
  {

  	int ret = 0;

  	if (!firmware_has_feature(FW_FEATURE_ISERIES))
  		return -ENODEV;

  	if (viopath_hostLp == HvLpIndexInvalid) {
  		vio_set_hostlp();
  		/* If we don't have a host, bail out */
  		if (viopath_hostLp == HvLpIndexInvalid)
  			return -ENODEV;
  	}

  	pr_info("vers " VIOCD_VERS ", hosting partition %d
  ", viopath_hostLp);

  
  	if (register_blkdev(VIOCD_MAJOR, VIOCD_DEVICE) != 0) {

  		pr_warning("Unable to get major %d for %s
  ",
  			   VIOCD_MAJOR, VIOCD_DEVICE);

  		return -EIO;
  	}
  
  	ret = viopath_open(viopath_hostLp, viomajorsubtype_cdio,
  			MAX_CD_REQ + 2);
  	if (ret) {

  		pr_warning("error opening path to host partition %d
  ",
  			   viopath_hostLp);

  		goto out_unregister;
  	}
  
  	/* Initialize our request handler */
  	vio_setHandler(viomajorsubtype_cdio, vio_handle_cd_event);

  	spin_lock_init(&viocd_reqlock);
  
  	ret = vio_register_driver(&viocd_driver);
  	if (ret)
  		goto out_free_info;

  	proc_create("iSeries/viocd", S_IFREG|S_IRUGO, NULL,
  		    &proc_viocd_operations);

  	return 0;
  
  out_free_info:

  	vio_clearHandler(viomajorsubtype_cdio);
  	viopath_close(viopath_hostLp, viomajorsubtype_cdio, MAX_CD_REQ + 2);
  out_unregister:
  	unregister_blkdev(VIOCD_MAJOR, VIOCD_DEVICE);
  	return ret;
  }
  
  static void __exit viocd_exit(void)
  {
  	remove_proc_entry("iSeries/viocd", NULL);
  	vio_unregister_driver(&viocd_driver);

  	viopath_close(viopath_hostLp, viomajorsubtype_cdio, MAX_CD_REQ + 2);
  	vio_clearHandler(viomajorsubtype_cdio);
  	unregister_blkdev(VIOCD_MAJOR, VIOCD_DEVICE);
  }
  
  module_init(viocd_init);
  module_exit(viocd_exit);
  MODULE_LICENSE("GPL");