/*
   * VME Bridge Framework
   *

   * Author: Martyn Welch <martyn.welch@ge.com>
   * Copyright 2008 GE Intelligent Platforms Embedded Systems, Inc.

   *
   * Based on work by Tom Armistead and Ajit Prem
   * Copyright 2004 Motorola Inc.
   *
   * 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.
   */

  #include <linux/module.h>
  #include <linux/moduleparam.h>
  #include <linux/mm.h>
  #include <linux/types.h>
  #include <linux/kernel.h>
  #include <linux/errno.h>
  #include <linux/pci.h>
  #include <linux/poll.h>
  #include <linux/highmem.h>
  #include <linux/interrupt.h>
  #include <linux/pagemap.h>
  #include <linux/device.h>
  #include <linux/dma-mapping.h>
  #include <linux/syscalls.h>

  #include <linux/mutex.h>

  #include <linux/spinlock.h>

  #include <linux/slab.h>

  #include <linux/vme.h>

  #include "vme_bridge.h"

  /* Bitmask and list of registered buses both protected by common mutex */

  static unsigned int vme_bus_numbers;

  static LIST_HEAD(vme_bus_list);
  static DEFINE_MUTEX(vme_buses_lock);

  static void __exit vme_exit(void);
  static int __init vme_init(void);

  static struct vme_dev *dev_to_vme_dev(struct device *dev)

  {

  	return container_of(dev, struct vme_dev, dev);

  }
  
  /*
   * Find the bridge that the resource is associated with.
   */
  static struct vme_bridge *find_bridge(struct vme_resource *resource)
  {
  	/* Get list to search */
  	switch (resource->type) {
  	case VME_MASTER:
  		return list_entry(resource->entry, struct vme_master_resource,
  			list)->parent;
  		break;
  	case VME_SLAVE:
  		return list_entry(resource->entry, struct vme_slave_resource,
  			list)->parent;
  		break;
  	case VME_DMA:
  		return list_entry(resource->entry, struct vme_dma_resource,
  			list)->parent;
  		break;

  	case VME_LM:
  		return list_entry(resource->entry, struct vme_lm_resource,
  			list)->parent;
  		break;

  	default:
  		printk(KERN_ERR "Unknown resource type
  ");
  		return NULL;
  		break;
  	}
  }
  
  /*
   * Allocate a contiguous block of memory for use by the driver. This is used to
   * create the buffers for the slave windows.

   */

  void *vme_alloc_consistent(struct vme_resource *resource, size_t size,

  	dma_addr_t *dma)
  {
  	struct vme_bridge *bridge;

  	if (resource == NULL) {
  		printk(KERN_ERR "No resource
  ");

  		return NULL;
  	}
  
  	bridge = find_bridge(resource);

  	if (bridge == NULL) {
  		printk(KERN_ERR "Can't find bridge
  ");

  		return NULL;
  	}

  	if (bridge->parent == NULL) {

  		printk(KERN_ERR "Dev entry NULL for bridge %s
  ", bridge->name);

  		return NULL;
  	}
  
  	if (bridge->alloc_consistent == NULL) {

  		printk(KERN_ERR "alloc_consistent not supported by bridge %s
  ",
  		       bridge->name);

  		return NULL;
  	}

  	return bridge->alloc_consistent(bridge->parent, size, dma);

  }
  EXPORT_SYMBOL(vme_alloc_consistent);
  
  /*
   * Free previously allocated contiguous block of memory.

   */
  void vme_free_consistent(struct vme_resource *resource, size_t size,
  	void *vaddr, dma_addr_t dma)
  {
  	struct vme_bridge *bridge;

  	if (resource == NULL) {
  		printk(KERN_ERR "No resource
  ");

  		return;
  	}
  
  	bridge = find_bridge(resource);

  	if (bridge == NULL) {
  		printk(KERN_ERR "Can't find bridge
  ");

  		return;
  	}

  	if (bridge->parent == NULL) {

  		printk(KERN_ERR "Dev entry NULL for bridge %s
  ", bridge->name);

  		return;
  	}
  
  	if (bridge->free_consistent == NULL) {

  		printk(KERN_ERR "free_consistent not supported by bridge %s
  ",
  		       bridge->name);

  		return;
  	}

  	bridge->free_consistent(bridge->parent, size, vaddr, dma);

  }
  EXPORT_SYMBOL(vme_free_consistent);
  
  size_t vme_get_size(struct vme_resource *resource)
  {
  	int enabled, retval;
  	unsigned long long base, size;
  	dma_addr_t buf_base;

  	u32 aspace, cycle, dwidth;

  
  	switch (resource->type) {
  	case VME_MASTER:
  		retval = vme_master_get(resource, &enabled, &base, &size,
  			&aspace, &cycle, &dwidth);
  
  		return size;
  		break;
  	case VME_SLAVE:
  		retval = vme_slave_get(resource, &enabled, &base, &size,
  			&buf_base, &aspace, &cycle);
  
  		return size;
  		break;
  	case VME_DMA:
  		return 0;
  		break;
  	default:
  		printk(KERN_ERR "Unknown resource type
  ");
  		return 0;
  		break;
  	}
  }
  EXPORT_SYMBOL(vme_get_size);

  int vme_check_window(u32 aspace, unsigned long long vme_base,
  		     unsigned long long size)

  {
  	int retval = 0;
  
  	switch (aspace) {
  	case VME_A16:
  		if (((vme_base + size) > VME_A16_MAX) ||
  				(vme_base > VME_A16_MAX))
  			retval = -EFAULT;
  		break;
  	case VME_A24:
  		if (((vme_base + size) > VME_A24_MAX) ||
  				(vme_base > VME_A24_MAX))
  			retval = -EFAULT;
  		break;
  	case VME_A32:
  		if (((vme_base + size) > VME_A32_MAX) ||
  				(vme_base > VME_A32_MAX))
  			retval = -EFAULT;
  		break;
  	case VME_A64:

  		if ((size != 0) && (vme_base > U64_MAX + 1 - size))
  			retval = -EFAULT;

  		break;
  	case VME_CRCSR:
  		if (((vme_base + size) > VME_CRCSR_MAX) ||
  				(vme_base > VME_CRCSR_MAX))
  			retval = -EFAULT;
  		break;
  	case VME_USER1:
  	case VME_USER2:
  	case VME_USER3:
  	case VME_USER4:
  		/* User Defined */
  		break;
  	default:

  		printk(KERN_ERR "Invalid address space
  ");

  		retval = -EINVAL;
  		break;
  	}
  
  	return retval;
  }

  EXPORT_SYMBOL(vme_check_window);

  static u32 vme_get_aspace(int am)
  {
  	switch (am) {
  	case 0x29:
  	case 0x2D:
  		return VME_A16;
  	case 0x38:
  	case 0x39:
  	case 0x3A:
  	case 0x3B:
  	case 0x3C:
  	case 0x3D:
  	case 0x3E:
  	case 0x3F:
  		return VME_A24;
  	case 0x8:
  	case 0x9:
  	case 0xA:
  	case 0xB:
  	case 0xC:
  	case 0xD:
  	case 0xE:
  	case 0xF:
  		return VME_A32;
  	case 0x0:
  	case 0x1:
  	case 0x3:
  		return VME_A64;
  	}
  
  	return 0;
  }

  /*
   * Request a slave image with specific attributes, return some unique
   * identifier.
   */

  struct vme_resource *vme_slave_request(struct vme_dev *vdev, u32 address,
  	u32 cycle)

  {
  	struct vme_bridge *bridge;
  	struct list_head *slave_pos = NULL;
  	struct vme_slave_resource *allocated_image = NULL;
  	struct vme_slave_resource *slave_image = NULL;
  	struct vme_resource *resource = NULL;

  	bridge = vdev->bridge;

  	if (bridge == NULL) {
  		printk(KERN_ERR "Can't find VME bus
  ");
  		goto err_bus;
  	}
  
  	/* Loop through slave resources */

  	list_for_each(slave_pos, &bridge->slave_resources) {

  		slave_image = list_entry(slave_pos,
  			struct vme_slave_resource, list);
  
  		if (slave_image == NULL) {

  			printk(KERN_ERR "Registered NULL Slave resource
  ");

  			continue;
  		}
  
  		/* Find an unlocked and compatible image */

  		mutex_lock(&slave_image->mtx);

  		if (((slave_image->address_attr & address) == address) &&

  			((slave_image->cycle_attr & cycle) == cycle) &&
  			(slave_image->locked == 0)) {
  
  			slave_image->locked = 1;

  			mutex_unlock(&slave_image->mtx);

  			allocated_image = slave_image;
  			break;
  		}

  		mutex_unlock(&slave_image->mtx);

  	}
  
  	/* No free image */
  	if (allocated_image == NULL)
  		goto err_image;
  
  	resource = kmalloc(sizeof(struct vme_resource), GFP_KERNEL);
  	if (resource == NULL) {
  		printk(KERN_WARNING "Unable to allocate resource structure
  ");
  		goto err_alloc;
  	}
  	resource->type = VME_SLAVE;

  	resource->entry = &allocated_image->list;

  
  	return resource;
  
  err_alloc:
  	/* Unlock image */

  	mutex_lock(&slave_image->mtx);

  	slave_image->locked = 0;

  	mutex_unlock(&slave_image->mtx);

  err_image:
  err_bus:
  	return NULL;
  }
  EXPORT_SYMBOL(vme_slave_request);

  int vme_slave_set(struct vme_resource *resource, int enabled,

  	unsigned long long vme_base, unsigned long long size,

  	dma_addr_t buf_base, u32 aspace, u32 cycle)

  {
  	struct vme_bridge *bridge = find_bridge(resource);
  	struct vme_slave_resource *image;
  	int retval;
  
  	if (resource->type != VME_SLAVE) {

  		printk(KERN_ERR "Not a slave resource
  ");

  		return -EINVAL;
  	}
  
  	image = list_entry(resource->entry, struct vme_slave_resource, list);
  
  	if (bridge->slave_set == NULL) {

  		printk(KERN_ERR "Function not supported
  ");

  		return -ENOSYS;
  	}

  	if (!(((image->address_attr & aspace) == aspace) &&

  		((image->cycle_attr & cycle) == cycle))) {

  		printk(KERN_ERR "Invalid attributes
  ");

  		return -EINVAL;
  	}
  
  	retval = vme_check_window(aspace, vme_base, size);

  	if (retval)

  		return retval;
  
  	return bridge->slave_set(image, enabled, vme_base, size, buf_base,
  		aspace, cycle);
  }
  EXPORT_SYMBOL(vme_slave_set);

  int vme_slave_get(struct vme_resource *resource, int *enabled,

  	unsigned long long *vme_base, unsigned long long *size,

  	dma_addr_t *buf_base, u32 *aspace, u32 *cycle)

  {
  	struct vme_bridge *bridge = find_bridge(resource);
  	struct vme_slave_resource *image;
  
  	if (resource->type != VME_SLAVE) {

  		printk(KERN_ERR "Not a slave resource
  ");

  		return -EINVAL;
  	}
  
  	image = list_entry(resource->entry, struct vme_slave_resource, list);

  	if (bridge->slave_get == NULL) {

  		printk(KERN_ERR "vme_slave_get not supported
  ");

  		return -EINVAL;
  	}
  
  	return bridge->slave_get(image, enabled, vme_base, size, buf_base,
  		aspace, cycle);
  }
  EXPORT_SYMBOL(vme_slave_get);
  
  void vme_slave_free(struct vme_resource *resource)
  {
  	struct vme_slave_resource *slave_image;
  
  	if (resource->type != VME_SLAVE) {

  		printk(KERN_ERR "Not a slave resource
  ");

  		return;
  	}
  
  	slave_image = list_entry(resource->entry, struct vme_slave_resource,
  		list);
  	if (slave_image == NULL) {

  		printk(KERN_ERR "Can't find slave resource
  ");

  		return;
  	}
  
  	/* Unlock image */

  	mutex_lock(&slave_image->mtx);

  	if (slave_image->locked == 0)
  		printk(KERN_ERR "Image is already free
  ");
  
  	slave_image->locked = 0;

  	mutex_unlock(&slave_image->mtx);

  
  	/* Free up resource memory */
  	kfree(resource);
  }
  EXPORT_SYMBOL(vme_slave_free);
  
  /*
   * Request a master image with specific attributes, return some unique
   * identifier.
   */

  struct vme_resource *vme_master_request(struct vme_dev *vdev, u32 address,
  	u32 cycle, u32 dwidth)

  {
  	struct vme_bridge *bridge;
  	struct list_head *master_pos = NULL;
  	struct vme_master_resource *allocated_image = NULL;
  	struct vme_master_resource *master_image = NULL;
  	struct vme_resource *resource = NULL;

  	bridge = vdev->bridge;

  	if (bridge == NULL) {
  		printk(KERN_ERR "Can't find VME bus
  ");
  		goto err_bus;
  	}
  
  	/* Loop through master resources */

  	list_for_each(master_pos, &bridge->master_resources) {

  		master_image = list_entry(master_pos,
  			struct vme_master_resource, list);
  
  		if (master_image == NULL) {
  			printk(KERN_WARNING "Registered NULL master resource
  ");
  			continue;
  		}
  
  		/* Find an unlocked and compatible image */

  		spin_lock(&master_image->lock);

  		if (((master_image->address_attr & address) == address) &&

  			((master_image->cycle_attr & cycle) == cycle) &&
  			((master_image->width_attr & dwidth) == dwidth) &&
  			(master_image->locked == 0)) {
  
  			master_image->locked = 1;

  			spin_unlock(&master_image->lock);

  			allocated_image = master_image;
  			break;
  		}

  		spin_unlock(&master_image->lock);

  	}
  
  	/* Check to see if we found a resource */
  	if (allocated_image == NULL) {
  		printk(KERN_ERR "Can't find a suitable resource
  ");
  		goto err_image;
  	}
  
  	resource = kmalloc(sizeof(struct vme_resource), GFP_KERNEL);
  	if (resource == NULL) {
  		printk(KERN_ERR "Unable to allocate resource structure
  ");
  		goto err_alloc;
  	}
  	resource->type = VME_MASTER;

  	resource->entry = &allocated_image->list;

  
  	return resource;

  err_alloc:
  	/* Unlock image */

  	spin_lock(&master_image->lock);

  	master_image->locked = 0;

  	spin_unlock(&master_image->lock);

  err_image:
  err_bus:
  	return NULL;
  }
  EXPORT_SYMBOL(vme_master_request);

  int vme_master_set(struct vme_resource *resource, int enabled,

  	unsigned long long vme_base, unsigned long long size, u32 aspace,
  	u32 cycle, u32 dwidth)

  {
  	struct vme_bridge *bridge = find_bridge(resource);
  	struct vme_master_resource *image;
  	int retval;
  
  	if (resource->type != VME_MASTER) {

  		printk(KERN_ERR "Not a master resource
  ");

  		return -EINVAL;
  	}
  
  	image = list_entry(resource->entry, struct vme_master_resource, list);
  
  	if (bridge->master_set == NULL) {

  		printk(KERN_WARNING "vme_master_set not supported
  ");

  		return -EINVAL;
  	}

  	if (!(((image->address_attr & aspace) == aspace) &&

  		((image->cycle_attr & cycle) == cycle) &&
  		((image->width_attr & dwidth) == dwidth))) {

  		printk(KERN_WARNING "Invalid attributes
  ");

  		return -EINVAL;
  	}
  
  	retval = vme_check_window(aspace, vme_base, size);

  	if (retval)

  		return retval;
  
  	return bridge->master_set(image, enabled, vme_base, size, aspace,
  		cycle, dwidth);
  }
  EXPORT_SYMBOL(vme_master_set);

  int vme_master_get(struct vme_resource *resource, int *enabled,

  	unsigned long long *vme_base, unsigned long long *size, u32 *aspace,
  	u32 *cycle, u32 *dwidth)

  {
  	struct vme_bridge *bridge = find_bridge(resource);
  	struct vme_master_resource *image;
  
  	if (resource->type != VME_MASTER) {

  		printk(KERN_ERR "Not a master resource
  ");

  		return -EINVAL;
  	}
  
  	image = list_entry(resource->entry, struct vme_master_resource, list);

  	if (bridge->master_get == NULL) {

  		printk(KERN_WARNING "%s not supported
  ", __func__);

  		return -EINVAL;
  	}
  
  	return bridge->master_get(image, enabled, vme_base, size, aspace,
  		cycle, dwidth);
  }
  EXPORT_SYMBOL(vme_master_get);
  
  /*
   * Read data out of VME space into a buffer.
   */

  ssize_t vme_master_read(struct vme_resource *resource, void *buf, size_t count,

  	loff_t offset)
  {
  	struct vme_bridge *bridge = find_bridge(resource);
  	struct vme_master_resource *image;
  	size_t length;
  
  	if (bridge->master_read == NULL) {

  		printk(KERN_WARNING "Reading from resource not supported
  ");

  		return -EINVAL;
  	}
  
  	if (resource->type != VME_MASTER) {

  		printk(KERN_ERR "Not a master resource
  ");

  		return -EINVAL;
  	}
  
  	image = list_entry(resource->entry, struct vme_master_resource, list);
  
  	length = vme_get_size(resource);
  
  	if (offset > length) {

  		printk(KERN_WARNING "Invalid Offset
  ");

  		return -EFAULT;
  	}
  
  	if ((offset + count) > length)
  		count = length - offset;
  
  	return bridge->master_read(image, buf, count, offset);
  
  }
  EXPORT_SYMBOL(vme_master_read);
  
  /*
   * Write data out to VME space from a buffer.
   */

  ssize_t vme_master_write(struct vme_resource *resource, void *buf,

  	size_t count, loff_t offset)
  {
  	struct vme_bridge *bridge = find_bridge(resource);
  	struct vme_master_resource *image;
  	size_t length;
  
  	if (bridge->master_write == NULL) {

  		printk(KERN_WARNING "Writing to resource not supported
  ");

  		return -EINVAL;
  	}
  
  	if (resource->type != VME_MASTER) {

  		printk(KERN_ERR "Not a master resource
  ");

  		return -EINVAL;
  	}
  
  	image = list_entry(resource->entry, struct vme_master_resource, list);
  
  	length = vme_get_size(resource);
  
  	if (offset > length) {

  		printk(KERN_WARNING "Invalid Offset
  ");

  		return -EFAULT;
  	}
  
  	if ((offset + count) > length)
  		count = length - offset;
  
  	return bridge->master_write(image, buf, count, offset);
  }
  EXPORT_SYMBOL(vme_master_write);
  
  /*
   * Perform RMW cycle to provided location.
   */

  unsigned int vme_master_rmw(struct vme_resource *resource, unsigned int mask,

  	unsigned int compare, unsigned int swap, loff_t offset)
  {
  	struct vme_bridge *bridge = find_bridge(resource);
  	struct vme_master_resource *image;
  
  	if (bridge->master_rmw == NULL) {

  		printk(KERN_WARNING "Writing to resource not supported
  ");

  		return -EINVAL;
  	}
  
  	if (resource->type != VME_MASTER) {

  		printk(KERN_ERR "Not a master resource
  ");

  		return -EINVAL;
  	}
  
  	image = list_entry(resource->entry, struct vme_master_resource, list);
  
  	return bridge->master_rmw(image, mask, compare, swap, offset);
  }
  EXPORT_SYMBOL(vme_master_rmw);

  int vme_master_mmap(struct vme_resource *resource, struct vm_area_struct *vma)
  {
  	struct vme_master_resource *image;
  	phys_addr_t phys_addr;
  	unsigned long vma_size;
  
  	if (resource->type != VME_MASTER) {
  		pr_err("Not a master resource
  ");
  		return -EINVAL;
  	}
  
  	image = list_entry(resource->entry, struct vme_master_resource, list);
  	phys_addr = image->bus_resource.start + (vma->vm_pgoff << PAGE_SHIFT);
  	vma_size = vma->vm_end - vma->vm_start;
  
  	if (phys_addr + vma_size > image->bus_resource.end + 1) {
  		pr_err("Map size cannot exceed the window size
  ");
  		return -EFAULT;
  	}
  
  	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
  
  	return vm_iomap_memory(vma, phys_addr, vma->vm_end - vma->vm_start);
  }
  EXPORT_SYMBOL(vme_master_mmap);

  void vme_master_free(struct vme_resource *resource)
  {
  	struct vme_master_resource *master_image;
  
  	if (resource->type != VME_MASTER) {

  		printk(KERN_ERR "Not a master resource
  ");

  		return;
  	}
  
  	master_image = list_entry(resource->entry, struct vme_master_resource,
  		list);
  	if (master_image == NULL) {

  		printk(KERN_ERR "Can't find master resource
  ");

  		return;
  	}
  
  	/* Unlock image */

  	spin_lock(&master_image->lock);

  	if (master_image->locked == 0)
  		printk(KERN_ERR "Image is already free
  ");
  
  	master_image->locked = 0;

  	spin_unlock(&master_image->lock);

  
  	/* Free up resource memory */
  	kfree(resource);
  }
  EXPORT_SYMBOL(vme_master_free);
  
  /*
   * Request a DMA controller with specific attributes, return some unique
   * identifier.
   */

  struct vme_resource *vme_dma_request(struct vme_dev *vdev, u32 route)

  {
  	struct vme_bridge *bridge;
  	struct list_head *dma_pos = NULL;
  	struct vme_dma_resource *allocated_ctrlr = NULL;
  	struct vme_dma_resource *dma_ctrlr = NULL;
  	struct vme_resource *resource = NULL;
  
  	/* XXX Not checking resource attributes */
  	printk(KERN_ERR "No VME resource Attribute tests done
  ");

  	bridge = vdev->bridge;

  	if (bridge == NULL) {
  		printk(KERN_ERR "Can't find VME bus
  ");
  		goto err_bus;
  	}
  
  	/* Loop through DMA resources */

  	list_for_each(dma_pos, &bridge->dma_resources) {

  		dma_ctrlr = list_entry(dma_pos,
  			struct vme_dma_resource, list);
  
  		if (dma_ctrlr == NULL) {

  			printk(KERN_ERR "Registered NULL DMA resource
  ");

  			continue;
  		}

  		/* Find an unlocked and compatible controller */

  		mutex_lock(&dma_ctrlr->mtx);

  		if (((dma_ctrlr->route_attr & route) == route) &&
  			(dma_ctrlr->locked == 0)) {

  			dma_ctrlr->locked = 1;

  			mutex_unlock(&dma_ctrlr->mtx);

  			allocated_ctrlr = dma_ctrlr;
  			break;
  		}

  		mutex_unlock(&dma_ctrlr->mtx);

  	}
  
  	/* Check to see if we found a resource */
  	if (allocated_ctrlr == NULL)
  		goto err_ctrlr;
  
  	resource = kmalloc(sizeof(struct vme_resource), GFP_KERNEL);
  	if (resource == NULL) {
  		printk(KERN_WARNING "Unable to allocate resource structure
  ");
  		goto err_alloc;
  	}
  	resource->type = VME_DMA;

  	resource->entry = &allocated_ctrlr->list;

  
  	return resource;
  
  err_alloc:
  	/* Unlock image */

  	mutex_lock(&dma_ctrlr->mtx);

  	dma_ctrlr->locked = 0;

  	mutex_unlock(&dma_ctrlr->mtx);

  err_ctrlr:
  err_bus:
  	return NULL;
  }

  EXPORT_SYMBOL(vme_dma_request);

  
  /*
   * Start new list
   */
  struct vme_dma_list *vme_new_dma_list(struct vme_resource *resource)
  {
  	struct vme_dma_resource *ctrlr;
  	struct vme_dma_list *dma_list;
  
  	if (resource->type != VME_DMA) {

  		printk(KERN_ERR "Not a DMA resource
  ");

  		return NULL;
  	}
  
  	ctrlr = list_entry(resource->entry, struct vme_dma_resource, list);

  	dma_list = kmalloc(sizeof(struct vme_dma_list), GFP_KERNEL);
  	if (dma_list == NULL) {

  		printk(KERN_ERR "Unable to allocate memory for new DMA list
  ");

  		return NULL;
  	}

  	INIT_LIST_HEAD(&dma_list->entries);

  	dma_list->parent = ctrlr;

  	mutex_init(&dma_list->mtx);

  
  	return dma_list;
  }
  EXPORT_SYMBOL(vme_new_dma_list);
  
  /*
   * Create "Pattern" type attributes
   */

  struct vme_dma_attr *vme_dma_pattern_attribute(u32 pattern, u32 type)

  {
  	struct vme_dma_attr *attributes;
  	struct vme_dma_pattern *pattern_attr;

  	attributes = kmalloc(sizeof(struct vme_dma_attr), GFP_KERNEL);
  	if (attributes == NULL) {

  		printk(KERN_ERR "Unable to allocate memory for attributes structure
  ");

  		goto err_attr;
  	}

  	pattern_attr = kmalloc(sizeof(struct vme_dma_pattern), GFP_KERNEL);
  	if (pattern_attr == NULL) {

  		printk(KERN_ERR "Unable to allocate memory for pattern attributes
  ");

  		goto err_pat;
  	}
  
  	attributes->type = VME_DMA_PATTERN;
  	attributes->private = (void *)pattern_attr;
  
  	pattern_attr->pattern = pattern;
  	pattern_attr->type = type;
  
  	return attributes;

  err_pat:
  	kfree(attributes);
  err_attr:
  	return NULL;
  }
  EXPORT_SYMBOL(vme_dma_pattern_attribute);
  
  /*
   * Create "PCI" type attributes
   */
  struct vme_dma_attr *vme_dma_pci_attribute(dma_addr_t address)
  {
  	struct vme_dma_attr *attributes;
  	struct vme_dma_pci *pci_attr;
  
  	/* XXX Run some sanity checks here */

  	attributes = kmalloc(sizeof(struct vme_dma_attr), GFP_KERNEL);
  	if (attributes == NULL) {

  		printk(KERN_ERR "Unable to allocate memory for attributes structure
  ");

  		goto err_attr;
  	}

  	pci_attr = kmalloc(sizeof(struct vme_dma_pci), GFP_KERNEL);
  	if (pci_attr == NULL) {

  		printk(KERN_ERR "Unable to allocate memory for PCI attributes
  ");

  		goto err_pci;
  	}
  
  
  
  	attributes->type = VME_DMA_PCI;
  	attributes->private = (void *)pci_attr;
  
  	pci_attr->address = address;
  
  	return attributes;

  err_pci:
  	kfree(attributes);
  err_attr:
  	return NULL;
  }
  EXPORT_SYMBOL(vme_dma_pci_attribute);
  
  /*
   * Create "VME" type attributes
   */
  struct vme_dma_attr *vme_dma_vme_attribute(unsigned long long address,

  	u32 aspace, u32 cycle, u32 dwidth)

  {
  	struct vme_dma_attr *attributes;
  	struct vme_dma_vme *vme_attr;

  	attributes = kmalloc(

  		sizeof(struct vme_dma_attr), GFP_KERNEL);

  	if (attributes == NULL) {

  		printk(KERN_ERR "Unable to allocate memory for attributes structure
  ");

  		goto err_attr;
  	}

  	vme_attr = kmalloc(sizeof(struct vme_dma_vme), GFP_KERNEL);
  	if (vme_attr == NULL) {

  		printk(KERN_ERR "Unable to allocate memory for VME attributes
  ");

  		goto err_vme;
  	}
  
  	attributes->type = VME_DMA_VME;
  	attributes->private = (void *)vme_attr;
  
  	vme_attr->address = address;
  	vme_attr->aspace = aspace;
  	vme_attr->cycle = cycle;
  	vme_attr->dwidth = dwidth;
  
  	return attributes;

  err_vme:
  	kfree(attributes);
  err_attr:
  	return NULL;
  }
  EXPORT_SYMBOL(vme_dma_vme_attribute);
  
  /*
   * Free attribute
   */
  void vme_dma_free_attribute(struct vme_dma_attr *attributes)
  {
  	kfree(attributes->private);
  	kfree(attributes);
  }
  EXPORT_SYMBOL(vme_dma_free_attribute);
  
  int vme_dma_list_add(struct vme_dma_list *list, struct vme_dma_attr *src,
  	struct vme_dma_attr *dest, size_t count)
  {
  	struct vme_bridge *bridge = list->parent->parent;
  	int retval;
  
  	if (bridge->dma_list_add == NULL) {

  		printk(KERN_WARNING "Link List DMA generation not supported
  ");

  		return -EINVAL;
  	}

  	if (!mutex_trylock(&list->mtx)) {

  		printk(KERN_ERR "Link List already submitted
  ");

  		return -EINVAL;
  	}
  
  	retval = bridge->dma_list_add(list, src, dest, count);

  	mutex_unlock(&list->mtx);

  
  	return retval;
  }
  EXPORT_SYMBOL(vme_dma_list_add);
  
  int vme_dma_list_exec(struct vme_dma_list *list)
  {
  	struct vme_bridge *bridge = list->parent->parent;
  	int retval;
  
  	if (bridge->dma_list_exec == NULL) {

  		printk(KERN_ERR "Link List DMA execution not supported
  ");

  		return -EINVAL;
  	}

  	mutex_lock(&list->mtx);

  
  	retval = bridge->dma_list_exec(list);

  	mutex_unlock(&list->mtx);

  
  	return retval;
  }
  EXPORT_SYMBOL(vme_dma_list_exec);
  
  int vme_dma_list_free(struct vme_dma_list *list)
  {
  	struct vme_bridge *bridge = list->parent->parent;
  	int retval;
  
  	if (bridge->dma_list_empty == NULL) {

  		printk(KERN_WARNING "Emptying of Link Lists not supported
  ");

  		return -EINVAL;
  	}

  	if (!mutex_trylock(&list->mtx)) {

  		printk(KERN_ERR "Link List in use
  ");

  		return -EINVAL;
  	}
  
  	/*

  	 * Empty out all of the entries from the DMA list. We need to go to the
  	 * low level driver as DMA entries are driver specific.

  	 */
  	retval = bridge->dma_list_empty(list);
  	if (retval) {

  		printk(KERN_ERR "Unable to empty link-list entries
  ");

  		mutex_unlock(&list->mtx);

  		return retval;
  	}

  	mutex_unlock(&list->mtx);

  	kfree(list);
  
  	return retval;
  }
  EXPORT_SYMBOL(vme_dma_list_free);
  
  int vme_dma_free(struct vme_resource *resource)
  {
  	struct vme_dma_resource *ctrlr;
  
  	if (resource->type != VME_DMA) {

  		printk(KERN_ERR "Not a DMA resource
  ");

  		return -EINVAL;
  	}
  
  	ctrlr = list_entry(resource->entry, struct vme_dma_resource, list);

  	if (!mutex_trylock(&ctrlr->mtx)) {

  		printk(KERN_ERR "Resource busy, can't free
  ");

  		return -EBUSY;
  	}

  	if (!(list_empty(&ctrlr->pending) && list_empty(&ctrlr->running))) {

  		printk(KERN_WARNING "Resource still processing transfers
  ");

  		mutex_unlock(&ctrlr->mtx);

  		return -EBUSY;
  	}
  
  	ctrlr->locked = 0;

  	mutex_unlock(&ctrlr->mtx);

  	kfree(resource);

  	return 0;
  }
  EXPORT_SYMBOL(vme_dma_free);

  void vme_bus_error_handler(struct vme_bridge *bridge,

  			   unsigned long long address, int am)

  {

  	struct list_head *handler_pos = NULL;
  	struct vme_error_handler *handler;

  	int handler_triggered = 0;

  	u32 aspace = vme_get_aspace(am);
  
  	list_for_each(handler_pos, &bridge->vme_error_handlers) {
  		handler = list_entry(handler_pos, struct vme_error_handler,
  				     list);
  		if ((aspace == handler->aspace) &&
  		    (address >= handler->start) &&
  		    (address < handler->end)) {
  			if (!handler->num_errors)
  				handler->first_error = address;
  			if (handler->num_errors != UINT_MAX)
  				handler->num_errors++;

  			handler_triggered = 1;

  		}

  	}

  
  	if (!handler_triggered)
  		dev_err(bridge->parent,
  			"Unhandled VME access error at address 0x%llx
  ",
  			address);

  }
  EXPORT_SYMBOL(vme_bus_error_handler);

  struct vme_error_handler *vme_register_error_handler(
  	struct vme_bridge *bridge, u32 aspace,
  	unsigned long long address, size_t len)

  {

  	struct vme_error_handler *handler;

  	handler = kmalloc(sizeof(*handler), GFP_KERNEL);
  	if (!handler)
  		return NULL;

  	handler->aspace = aspace;
  	handler->start = address;
  	handler->end = address + len;
  	handler->num_errors = 0;
  	handler->first_error = 0;
  	list_add_tail(&handler->list, &bridge->vme_error_handlers);

  	return handler;

  }

  EXPORT_SYMBOL(vme_register_error_handler);

  void vme_unregister_error_handler(struct vme_error_handler *handler)

  {

  	list_del(&handler->list);
  	kfree(handler);

  }

  EXPORT_SYMBOL(vme_unregister_error_handler);

  void vme_irq_handler(struct vme_bridge *bridge, int level, int statid)
  {
  	void (*call)(int, int, void *);
  	void *priv_data;
  
  	call = bridge->irq[level - 1].callback[statid].func;
  	priv_data = bridge->irq[level - 1].callback[statid].priv_data;
  
  	if (call != NULL)
  		call(level, statid, priv_data);
  	else

  		printk(KERN_WARNING "Spurious VME interrupt, level:%x, vector:%x
  ",

  		       level, statid);

  }
  EXPORT_SYMBOL(vme_irq_handler);

  int vme_irq_request(struct vme_dev *vdev, int level, int statid,

  	void (*callback)(int, int, void *),

  	void *priv_data)
  {
  	struct vme_bridge *bridge;

  	bridge = vdev->bridge;

  	if (bridge == NULL) {
  		printk(KERN_ERR "Can't find VME bus
  ");
  		return -EINVAL;
  	}

  	if ((level < 1) || (level > 7)) {

  		printk(KERN_ERR "Invalid interrupt level
  ");

  		return -EINVAL;
  	}

  	if (bridge->irq_set == NULL) {
  		printk(KERN_ERR "Configuring interrupts not supported
  ");

  		return -EINVAL;
  	}

  	mutex_lock(&bridge->irq_mtx);

  
  	if (bridge->irq[level - 1].callback[statid].func) {

  		mutex_unlock(&bridge->irq_mtx);

  		printk(KERN_WARNING "VME Interrupt already taken
  ");
  		return -EBUSY;
  	}
  
  	bridge->irq[level - 1].count++;
  	bridge->irq[level - 1].callback[statid].priv_data = priv_data;
  	bridge->irq[level - 1].callback[statid].func = callback;
  
  	/* Enable IRQ level */

  	bridge->irq_set(bridge, level, 1, 1);

  	mutex_unlock(&bridge->irq_mtx);

  
  	return 0;

  }

  EXPORT_SYMBOL(vme_irq_request);

  void vme_irq_free(struct vme_dev *vdev, int level, int statid)

  {
  	struct vme_bridge *bridge;

  	bridge = vdev->bridge;

  	if (bridge == NULL) {
  		printk(KERN_ERR "Can't find VME bus
  ");
  		return;
  	}

  	if ((level < 1) || (level > 7)) {

  		printk(KERN_ERR "Invalid interrupt level
  ");

  		return;
  	}

  	if (bridge->irq_set == NULL) {
  		printk(KERN_ERR "Configuring interrupts not supported
  ");

  		return;
  	}

  	mutex_lock(&bridge->irq_mtx);

  
  	bridge->irq[level - 1].count--;
  
  	/* Disable IRQ level if no more interrupts attached at this level*/
  	if (bridge->irq[level - 1].count == 0)

  		bridge->irq_set(bridge, level, 0, 1);

  
  	bridge->irq[level - 1].callback[statid].func = NULL;
  	bridge->irq[level - 1].callback[statid].priv_data = NULL;

  	mutex_unlock(&bridge->irq_mtx);

  }

  EXPORT_SYMBOL(vme_irq_free);

  int vme_irq_generate(struct vme_dev *vdev, int level, int statid)

  {
  	struct vme_bridge *bridge;

  	bridge = vdev->bridge;

  	if (bridge == NULL) {
  		printk(KERN_ERR "Can't find VME bus
  ");
  		return -EINVAL;
  	}

  	if ((level < 1) || (level > 7)) {

  		printk(KERN_WARNING "Invalid interrupt level
  ");
  		return -EINVAL;
  	}

  	if (bridge->irq_generate == NULL) {

  		printk(KERN_WARNING "Interrupt generation not supported
  ");

  		return -EINVAL;
  	}

  	return bridge->irq_generate(bridge, level, statid);

  }

  EXPORT_SYMBOL(vme_irq_generate);

  /*
   * Request the location monitor, return resource or NULL
   */

  struct vme_resource *vme_lm_request(struct vme_dev *vdev)

  {
  	struct vme_bridge *bridge;

  	struct list_head *lm_pos = NULL;
  	struct vme_lm_resource *allocated_lm = NULL;
  	struct vme_lm_resource *lm = NULL;
  	struct vme_resource *resource = NULL;

  	bridge = vdev->bridge;

  	if (bridge == NULL) {
  		printk(KERN_ERR "Can't find VME bus
  ");

  		goto err_bus;
  	}
  
  	/* Loop through DMA resources */

  	list_for_each(lm_pos, &bridge->lm_resources) {

  		lm = list_entry(lm_pos,
  			struct vme_lm_resource, list);
  
  		if (lm == NULL) {

  			printk(KERN_ERR "Registered NULL Location Monitor resource
  ");

  			continue;
  		}
  
  		/* Find an unlocked controller */

  		mutex_lock(&lm->mtx);

  		if (lm->locked == 0) {
  			lm->locked = 1;

  			mutex_unlock(&lm->mtx);

  			allocated_lm = lm;
  			break;
  		}

  		mutex_unlock(&lm->mtx);

  	}
  
  	/* Check to see if we found a resource */
  	if (allocated_lm == NULL)
  		goto err_lm;
  
  	resource = kmalloc(sizeof(struct vme_resource), GFP_KERNEL);
  	if (resource == NULL) {
  		printk(KERN_ERR "Unable to allocate resource structure
  ");
  		goto err_alloc;
  	}
  	resource->type = VME_LM;

  	resource->entry = &allocated_lm->list;

  
  	return resource;
  
  err_alloc:
  	/* Unlock image */

  	mutex_lock(&lm->mtx);

  	lm->locked = 0;

  	mutex_unlock(&lm->mtx);

  err_lm:
  err_bus:
  	return NULL;
  }
  EXPORT_SYMBOL(vme_lm_request);
  
  int vme_lm_count(struct vme_resource *resource)
  {
  	struct vme_lm_resource *lm;
  
  	if (resource->type != VME_LM) {
  		printk(KERN_ERR "Not a Location Monitor resource
  ");
  		return -EINVAL;
  	}
  
  	lm = list_entry(resource->entry, struct vme_lm_resource, list);
  
  	return lm->monitors;
  }
  EXPORT_SYMBOL(vme_lm_count);
  
  int vme_lm_set(struct vme_resource *resource, unsigned long long lm_base,

  	u32 aspace, u32 cycle)

  {
  	struct vme_bridge *bridge = find_bridge(resource);
  	struct vme_lm_resource *lm;
  
  	if (resource->type != VME_LM) {
  		printk(KERN_ERR "Not a Location Monitor resource
  ");

  		return -EINVAL;
  	}

  	lm = list_entry(resource->entry, struct vme_lm_resource, list);

  	if (bridge->lm_set == NULL) {

  		printk(KERN_ERR "vme_lm_set not supported
  ");

  		return -EINVAL;
  	}

  	return bridge->lm_set(lm, lm_base, aspace, cycle);

  }
  EXPORT_SYMBOL(vme_lm_set);

  int vme_lm_get(struct vme_resource *resource, unsigned long long *lm_base,

  	u32 *aspace, u32 *cycle)

  {

  	struct vme_bridge *bridge = find_bridge(resource);
  	struct vme_lm_resource *lm;

  	if (resource->type != VME_LM) {
  		printk(KERN_ERR "Not a Location Monitor resource
  ");

  		return -EINVAL;
  	}

  	lm = list_entry(resource->entry, struct vme_lm_resource, list);

  	if (bridge->lm_get == NULL) {

  		printk(KERN_ERR "vme_lm_get not supported
  ");

  		return -EINVAL;
  	}

  	return bridge->lm_get(lm, lm_base, aspace, cycle);

  }
  EXPORT_SYMBOL(vme_lm_get);

  int vme_lm_attach(struct vme_resource *resource, int monitor,
  	void (*callback)(int))

  {

  	struct vme_bridge *bridge = find_bridge(resource);
  	struct vme_lm_resource *lm;

  	if (resource->type != VME_LM) {
  		printk(KERN_ERR "Not a Location Monitor resource
  ");

  		return -EINVAL;
  	}

  	lm = list_entry(resource->entry, struct vme_lm_resource, list);

  	if (bridge->lm_attach == NULL) {

  		printk(KERN_ERR "vme_lm_attach not supported
  ");

  		return -EINVAL;
  	}

  	return bridge->lm_attach(lm, monitor, callback);

  }
  EXPORT_SYMBOL(vme_lm_attach);

  int vme_lm_detach(struct vme_resource *resource, int monitor)

  {

  	struct vme_bridge *bridge = find_bridge(resource);
  	struct vme_lm_resource *lm;

  	if (resource->type != VME_LM) {
  		printk(KERN_ERR "Not a Location Monitor resource
  ");

  		return -EINVAL;
  	}

  	lm = list_entry(resource->entry, struct vme_lm_resource, list);

  	if (bridge->lm_detach == NULL) {

  		printk(KERN_ERR "vme_lm_detach not supported
  ");

  		return -EINVAL;
  	}

  	return bridge->lm_detach(lm, monitor);

  }
  EXPORT_SYMBOL(vme_lm_detach);

  void vme_lm_free(struct vme_resource *resource)
  {
  	struct vme_lm_resource *lm;
  
  	if (resource->type != VME_LM) {
  		printk(KERN_ERR "Not a Location Monitor resource
  ");
  		return;
  	}
  
  	lm = list_entry(resource->entry, struct vme_lm_resource, list);

  	mutex_lock(&lm->mtx);

  	/* XXX
  	 * Check to see that there aren't any callbacks still attached, if
  	 * there are we should probably be detaching them!
  	 */

  
  	lm->locked = 0;

  	mutex_unlock(&lm->mtx);

  
  	kfree(resource);

  }
  EXPORT_SYMBOL(vme_lm_free);

  int vme_slot_num(struct vme_dev *vdev)

  {
  	struct vme_bridge *bridge;

  	bridge = vdev->bridge;

  	if (bridge == NULL) {
  		printk(KERN_ERR "Can't find VME bus
  ");
  		return -EINVAL;
  	}
  
  	if (bridge->slot_get == NULL) {

  		printk(KERN_WARNING "vme_slot_num not supported
  ");

  		return -EINVAL;
  	}

  	return bridge->slot_get(bridge);

  }

  EXPORT_SYMBOL(vme_slot_num);

  int vme_bus_num(struct vme_dev *vdev)
  {
  	struct vme_bridge *bridge;
  
  	bridge = vdev->bridge;
  	if (bridge == NULL) {
  		pr_err("Can't find VME bus
  ");
  		return -EINVAL;
  	}
  
  	return bridge->num;
  }
  EXPORT_SYMBOL(vme_bus_num);

  
  /* - Bridge Registration --------------------------------------------------- */

  static void vme_dev_release(struct device *dev)
  {
  	kfree(dev_to_vme_dev(dev));
  }

  /* Common bridge initialization */
  struct vme_bridge *vme_init_bridge(struct vme_bridge *bridge)
  {
  	INIT_LIST_HEAD(&bridge->vme_error_handlers);
  	INIT_LIST_HEAD(&bridge->master_resources);
  	INIT_LIST_HEAD(&bridge->slave_resources);
  	INIT_LIST_HEAD(&bridge->dma_resources);
  	INIT_LIST_HEAD(&bridge->lm_resources);
  	mutex_init(&bridge->irq_mtx);
  
  	return bridge;
  }
  EXPORT_SYMBOL(vme_init_bridge);

  int vme_register_bridge(struct vme_bridge *bridge)

  {
  	int i;

  	int ret = -1;

  	mutex_lock(&vme_buses_lock);

  	for (i = 0; i < sizeof(vme_bus_numbers) * 8; i++) {

  		if ((vme_bus_numbers & (1 << i)) == 0) {
  			vme_bus_numbers |= (1 << i);
  			bridge->num = i;

  			INIT_LIST_HEAD(&bridge->devices);

  			list_add_tail(&bridge->bus_list, &vme_bus_list);
  			ret = 0;

  			break;
  		}
  	}

  	mutex_unlock(&vme_buses_lock);

  	return ret;

  }

  EXPORT_SYMBOL(vme_register_bridge);

  void vme_unregister_bridge(struct vme_bridge *bridge)

  {

  	struct vme_dev *vdev;
  	struct vme_dev *tmp;

  	mutex_lock(&vme_buses_lock);
  	vme_bus_numbers &= ~(1 << bridge->num);

  	list_for_each_entry_safe(vdev, tmp, &bridge->devices, bridge_list) {
  		list_del(&vdev->drv_list);
  		list_del(&vdev->bridge_list);
  		device_unregister(&vdev->dev);
  	}

  	list_del(&bridge->bus_list);
  	mutex_unlock(&vme_buses_lock);

  }

  EXPORT_SYMBOL(vme_unregister_bridge);

  /* - Driver Registration --------------------------------------------------- */
  
  static int __vme_register_driver_bus(struct vme_driver *drv,
  	struct vme_bridge *bridge, unsigned int ndevs)
  {
  	int err;
  	unsigned int i;
  	struct vme_dev *vdev;
  	struct vme_dev *tmp;
  
  	for (i = 0; i < ndevs; i++) {
  		vdev = kzalloc(sizeof(struct vme_dev), GFP_KERNEL);
  		if (!vdev) {
  			err = -ENOMEM;

  			goto err_devalloc;
  		}

  		vdev->num = i;

  		vdev->bridge = bridge;

  		vdev->dev.platform_data = drv;
  		vdev->dev.release = vme_dev_release;

  		vdev->dev.parent = bridge->parent;
  		vdev->dev.bus = &vme_bus_type;

  		dev_set_name(&vdev->dev, "%s.%u-%u", drv->name, bridge->num,
  			vdev->num);

  		err = device_register(&vdev->dev);
  		if (err)

  			goto err_reg;

  		if (vdev->dev.platform_data) {
  			list_add_tail(&vdev->drv_list, &drv->devices);
  			list_add_tail(&vdev->bridge_list, &bridge->devices);
  		} else
  			device_unregister(&vdev->dev);
  	}
  	return 0;

  err_reg:

  	put_device(&vdev->dev);

  	kfree(vdev);

  err_devalloc:

  	list_for_each_entry_safe(vdev, tmp, &drv->devices, drv_list) {
  		list_del(&vdev->drv_list);
  		list_del(&vdev->bridge_list);

  		device_unregister(&vdev->dev);

  	}

  	return err;

  }

  static int __vme_register_driver(struct vme_driver *drv, unsigned int ndevs)

  {

  	struct vme_bridge *bridge;
  	int err = 0;

  	mutex_lock(&vme_buses_lock);
  	list_for_each_entry(bridge, &vme_bus_list, bus_list) {
  		/*
  		 * This cannot cause trouble as we already have vme_buses_lock
  		 * and if the bridge is removed, it will have to go through
  		 * vme_unregister_bridge() to do it (which calls remove() on
  		 * the bridge which in turn tries to acquire vme_buses_lock and

  		 * will have to wait).

  		 */
  		err = __vme_register_driver_bus(drv, bridge, ndevs);
  		if (err)
  			break;

  	}

  	mutex_unlock(&vme_buses_lock);
  	return err;

  }

  int vme_register_driver(struct vme_driver *drv, unsigned int ndevs)

  {

  	int err;

  	drv->driver.name = drv->name;
  	drv->driver.bus = &vme_bus_type;

  	INIT_LIST_HEAD(&drv->devices);
  
  	err = driver_register(&drv->driver);
  	if (err)
  		return err;

  	err = __vme_register_driver(drv, ndevs);
  	if (err)
  		driver_unregister(&drv->driver);
  
  	return err;

  }
  EXPORT_SYMBOL(vme_register_driver);

  void vme_unregister_driver(struct vme_driver *drv)

  {

  	struct vme_dev *dev, *dev_tmp;
  
  	mutex_lock(&vme_buses_lock);
  	list_for_each_entry_safe(dev, dev_tmp, &drv->devices, drv_list) {
  		list_del(&dev->drv_list);
  		list_del(&dev->bridge_list);
  		device_unregister(&dev->dev);
  	}
  	mutex_unlock(&vme_buses_lock);

  	driver_unregister(&drv->driver);
  }
  EXPORT_SYMBOL(vme_unregister_driver);
  
  /* - Bus Registration ------------------------------------------------------ */

  static int vme_bus_match(struct device *dev, struct device_driver *drv)
  {

  	struct vme_driver *vme_drv;

  	vme_drv = container_of(drv, struct vme_driver, driver);

  	if (dev->platform_data == vme_drv) {
  		struct vme_dev *vdev = dev_to_vme_dev(dev);

  		if (vme_drv->match && vme_drv->match(vdev))
  			return 1;

  		dev->platform_data = NULL;

  	}

  	return 0;
  }
  
  static int vme_bus_probe(struct device *dev)
  {

  	int retval = -ENODEV;

  	struct vme_driver *driver;
  	struct vme_dev *vdev = dev_to_vme_dev(dev);

  	driver = dev->platform_data;

  	if (driver->probe != NULL)

  		retval = driver->probe(vdev);

  
  	return retval;
  }
  
  static int vme_bus_remove(struct device *dev)
  {

  	int retval = -ENODEV;

  	struct vme_driver *driver;
  	struct vme_dev *vdev = dev_to_vme_dev(dev);

  	driver = dev->platform_data;

  	if (driver->remove != NULL)

  		retval = driver->remove(vdev);

  
  	return retval;
  }
  
  struct bus_type vme_bus_type = {
  	.name = "vme",
  	.match = vme_bus_match,
  	.probe = vme_bus_probe,
  	.remove = vme_bus_remove,
  };
  EXPORT_SYMBOL(vme_bus_type);

  static int __init vme_init(void)

  {
  	return bus_register(&vme_bus_type);
  }

  static void __exit vme_exit(void)

  {
  	bus_unregister(&vme_bus_type);
  }

  subsys_initcall(vme_init);

  module_exit(vme_exit);