aboutsummaryrefslogtreecommitdiff
path: root/drivers/staging/vme/devices/vme_user.c
diff options
context:
space:
mode:
authorMartyn Welch <martyn.welch@gefanuc.com>2009-07-31 09:28:17 +0100
committerGreg Kroah-Hartman <gregkh@suse.de>2009-09-15 12:02:09 -0700
commitf00a86d98a1ec3e99d352cda926fab767ba43b1f (patch)
tree47326cc6feafea92714d9f18d5976e82879da287 /drivers/staging/vme/devices/vme_user.c
parenta17a75e2666f7175baac838bc4b6d11324dca3ef (diff)
downloadlinaro-lsk-f00a86d98a1ec3e99d352cda926fab767ba43b1f.tar.gz
Staging: vme: add VME userspace driver
Adds a VME userspace access driver Signed-off-by: Martyn Welch <martyn.welch@gefanuc.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/staging/vme/devices/vme_user.c')
-rw-r--r--drivers/staging/vme/devices/vme_user.c771
1 files changed, 771 insertions, 0 deletions
diff --git a/drivers/staging/vme/devices/vme_user.c b/drivers/staging/vme/devices/vme_user.c
new file mode 100644
index 00000000000..10294ab1c40
--- /dev/null
+++ b/drivers/staging/vme/devices/vme_user.c
@@ -0,0 +1,771 @@
+/*
+ * VMEbus User access driver
+ *
+ * Author: Martyn Welch <martyn.welch@gefanuc.com>
+ * Copyright 2008 GE Fanuc 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/cdev.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/ioctl.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/pagemap.h>
+#include <linux/pci.h>
+#include <linux/semaphore.h>
+#include <linux/spinlock.h>
+#include <linux/syscalls.h>
+#include <linux/types.h>
+#include <linux/version.h>
+
+#include <asm/io.h>
+#include <asm/uaccess.h>
+
+#include "../vme.h"
+#include "vme_user.h"
+
+/* Currently Documentation/devices.txt defines the following for VME:
+ *
+ * 221 char VME bus
+ * 0 = /dev/bus/vme/m0 First master image
+ * 1 = /dev/bus/vme/m1 Second master image
+ * 2 = /dev/bus/vme/m2 Third master image
+ * 3 = /dev/bus/vme/m3 Fourth master image
+ * 4 = /dev/bus/vme/s0 First slave image
+ * 5 = /dev/bus/vme/s1 Second slave image
+ * 6 = /dev/bus/vme/s2 Third slave image
+ * 7 = /dev/bus/vme/s3 Fourth slave image
+ * 8 = /dev/bus/vme/ctl Control
+ *
+ * It is expected that all VME bus drivers will use the
+ * same interface. For interface documentation see
+ * http://www.vmelinux.org/.
+ *
+ * However the VME driver at http://www.vmelinux.org/ is rather old and doesn't
+ * even support the tsi148 chipset (which has 8 master and 8 slave windows).
+ * We'll run with this or now as far as possible, however it probably makes
+ * sense to get rid of the old mappings and just do everything dynamically.
+ *
+ * So for now, we'll restrict the driver to providing 4 masters and 4 slaves as
+ * defined above and try to support at least some of the interface from
+ * http://www.vmelinux.org/ as an alternative drive can be written providing a
+ * saner interface later.
+ */
+#define VME_MAJOR 221 /* VME Major Device Number */
+#define VME_DEVS 9 /* Number of dev entries */
+
+#define MASTER_MINOR 0
+#define MASTER_MAX 3
+#define SLAVE_MINOR 4
+#define SLAVE_MAX 7
+#define CONTROL_MINOR 8
+
+#define PCI_BUF_SIZE 0x20000 /* Size of one slave image buffer */
+
+/*
+ * Structure to handle image related parameters.
+ */
+typedef struct {
+ void __iomem *kern_buf; /* Buffer address in kernel space */
+ dma_addr_t pci_buf; /* Buffer address in PCI address space */
+ unsigned long long size_buf; /* Buffer size */
+ struct semaphore sem; /* Semaphore for locking image */
+ struct device *device; /* Sysfs device */
+ struct vme_resource *resource; /* VME resource */
+ int users; /* Number of current users */
+} image_desc_t;
+static image_desc_t image[VME_DEVS];
+
+typedef struct {
+ unsigned long reads;
+ unsigned long writes;
+ unsigned long ioctls;
+ unsigned long irqs;
+ unsigned long berrs;
+ unsigned long dmaErrors;
+ unsigned long timeouts;
+ unsigned long external;
+} driver_stats_t;
+static driver_stats_t statistics;
+
+struct cdev *vme_user_cdev; /* Character device */
+struct class *vme_user_sysfs_class; /* Sysfs class */
+struct device *vme_user_bridge; /* Pointer to the bridge device */
+
+static char driver_name[] = "vme_user";
+
+static const int type[VME_DEVS] = { MASTER_MINOR, MASTER_MINOR,
+ MASTER_MINOR, MASTER_MINOR,
+ SLAVE_MINOR, SLAVE_MINOR,
+ SLAVE_MINOR, SLAVE_MINOR,
+ CONTROL_MINOR
+ };
+
+
+static int vme_user_open(struct inode *, struct file *);
+static int vme_user_release(struct inode *, struct file *);
+static ssize_t vme_user_read(struct file *, char *, size_t, loff_t *);
+static ssize_t vme_user_write(struct file *, const char *, size_t, loff_t *);
+static loff_t vme_user_llseek(struct file *, loff_t, int);
+static int vme_user_ioctl(struct inode *, struct file *, unsigned int,
+ unsigned long);
+
+static int __init vme_user_probe(struct device *dev);
+
+static struct file_operations vme_user_fops = {
+ .open = vme_user_open,
+ .release = vme_user_release,
+ .read = vme_user_read,
+ .write = vme_user_write,
+ .llseek = vme_user_llseek,
+ .ioctl = vme_user_ioctl,
+};
+
+
+/*
+ * Reset all the statistic counters
+ */
+static void reset_counters(void)
+{
+ statistics.reads = 0;
+ statistics.writes = 0;
+ statistics.ioctls = 0;
+ statistics.irqs = 0;
+ statistics.berrs = 0;
+ statistics.dmaErrors = 0;
+ statistics.timeouts = 0;
+}
+
+void lmcall(int monitor)
+{
+ printk("Caught Location Monitor %d access\n", monitor);
+}
+
+static void tests(void)
+{
+ struct vme_resource *dma_res;
+ struct vme_dma_list *dma_list;
+ struct vme_dma_attr *pattern_attr, *vme_attr;
+
+ int retval;
+ unsigned int data;
+
+ printk("Running VME DMA test\n");
+ dma_res = vme_request_dma(vme_user_bridge);
+ dma_list = vme_new_dma_list(dma_res);
+ pattern_attr = vme_dma_pattern_attribute(0x0,
+ VME_DMA_PATTERN_WORD |
+ VME_DMA_PATTERN_INCREMENT);
+ vme_attr = vme_dma_vme_attribute(0x10000, VME_A32,
+ VME_SCT, VME_D32);
+ retval = vme_dma_list_add(dma_list, pattern_attr,
+ vme_attr, 0x10000);
+#if 0
+ vme_dma_free_attribute(vme_attr);
+ vme_attr = vme_dma_vme_attribute(0x20000, VME_A32,
+ VME_SCT, VME_D32);
+ retval = vme_dma_list_add(dma_list, pattern_attr,
+ vme_attr, 0x10000);
+#endif
+ retval = vme_dma_list_exec(dma_list);
+ vme_dma_free_attribute(pattern_attr);
+ vme_dma_free_attribute(vme_attr);
+ vme_dma_list_free(dma_list);
+#if 0
+ printk("Generating a VME interrupt\n");
+ vme_generate_irq(dma_res, 0x3, 0xaa);
+ printk("Interrupt returned\n");
+#endif
+ vme_dma_free(dma_res);
+
+ /* Attempt RMW */
+ data = vme_master_rmw(image[0].resource, 0x80000000, 0x00000000,
+ 0x80000000, 0);
+ printk("RMW returned 0x%8.8x\n", data);
+
+
+ /* Location Monitor */
+ printk("vme_lm_set:%d\n", vme_lm_set(vme_user_bridge, 0x60000, VME_A32, VME_SCT | VME_USER | VME_DATA));
+ printk("vme_lm_attach:%d\n", vme_lm_attach(vme_user_bridge, 0, lmcall));
+
+ printk("Board in VME slot:%d\n", vme_slot_get(vme_user_bridge));
+}
+
+static int vme_user_open(struct inode *inode, struct file *file)
+{
+ int err;
+ unsigned int minor = MINOR(inode->i_rdev);
+
+ down(&image[minor].sem);
+ /* Only allow device to be opened if a resource is allocated */
+ if (image[minor].resource == NULL) {
+ printk(KERN_ERR "No resources allocated for device\n");
+ err = -EINVAL;
+ goto err_res;
+ }
+
+ /* Increment user count */
+ image[minor].users++;
+
+ up(&image[minor].sem);
+
+ return 0;
+
+err_res:
+ up(&image[minor].sem);
+
+ return err;
+}
+
+static int vme_user_release(struct inode *inode, struct file *file)
+{
+ unsigned int minor = MINOR(inode->i_rdev);
+
+ down(&image[minor].sem);
+
+ /* Decrement user count */
+ image[minor].users--;
+
+ up(&image[minor].sem);
+
+ return 0;
+}
+
+/*
+ * We are going ot alloc a page during init per window for small transfers.
+ * Small transfers will go VME -> buffer -> user space. Larger (more than a
+ * page) transfers will lock the user space buffer into memory and then
+ * transfer the data directly into the user space buffers.
+ */
+static ssize_t resource_to_user(int minor, char __user *buf, size_t count,
+ loff_t *ppos)
+{
+ ssize_t retval;
+ ssize_t copied = 0;
+
+ if (count <= image[minor].size_buf) {
+ /* We copy to kernel buffer */
+ copied = vme_master_read(image[minor].resource,
+ image[minor].kern_buf, count, *ppos);
+ if (copied < 0) {
+ return (int)copied;
+ }
+
+ retval = __copy_to_user(buf, image[minor].kern_buf,
+ (unsigned long)copied);
+ if (retval != 0) {
+ copied = (copied - retval);
+ printk("User copy failed\n");
+ return -EINVAL;
+ }
+
+ } else {
+ /* XXX Need to write this */
+ printk("Currently don't support large transfers\n");
+ /* Map in pages from userspace */
+
+ /* Call vme_master_read to do the transfer */
+ return -EINVAL;
+ }
+
+ return copied;
+}
+
+/*
+ * We are going ot alloc a page during init per window for small transfers.
+ * Small transfers will go user space -> buffer -> VME. Larger (more than a
+ * page) transfers will lock the user space buffer into memory and then
+ * transfer the data directly from the user space buffers out to VME.
+ */
+static ssize_t resource_from_user(unsigned int minor, const char *buf,
+ size_t count, loff_t *ppos)
+{
+ ssize_t retval;
+ ssize_t copied = 0;
+
+ if (count <= image[minor].size_buf) {
+ retval = __copy_from_user(image[minor].kern_buf, buf,
+ (unsigned long)count);
+ if (retval != 0)
+ copied = (copied - retval);
+ else
+ copied = count;
+
+ copied = vme_master_write(image[minor].resource,
+ image[minor].kern_buf, copied, *ppos);
+ } else {
+ /* XXX Need to write this */
+ printk("Currently don't support large transfers\n");
+ /* Map in pages from userspace */
+
+ /* Call vme_master_write to do the transfer */
+ return -EINVAL;
+ }
+
+ return copied;
+}
+
+static ssize_t buffer_to_user(unsigned int minor, char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ void __iomem *image_ptr;
+ ssize_t retval;
+
+ image_ptr = image[minor].kern_buf + *ppos;
+
+ retval = __copy_to_user(buf, image_ptr, (unsigned long)count);
+ if (retval != 0) {
+ retval = (count - retval);
+ printk(KERN_WARNING "Partial copy to userspace\n");
+ } else
+ retval = count;
+
+ /* Return number of bytes successfully read */
+ return retval;
+}
+
+static ssize_t buffer_from_user(unsigned int minor, const char *buf,
+ size_t count, loff_t *ppos)
+{
+ void __iomem *image_ptr;
+ size_t retval;
+
+ image_ptr = image[minor].kern_buf + *ppos;
+
+ retval = __copy_from_user(image_ptr, buf, (unsigned long)count);
+ if (retval != 0) {
+ retval = (count - retval);
+ printk(KERN_WARNING "Partial copy to userspace\n");
+ } else
+ retval = count;
+
+ /* Return number of bytes successfully read */
+ return retval;
+}
+
+static ssize_t vme_user_read(struct file *file, char *buf, size_t count,
+ loff_t * ppos)
+{
+ unsigned int minor = MINOR(file->f_dentry->d_inode->i_rdev);
+ ssize_t retval;
+ size_t image_size;
+ size_t okcount;
+
+ down(&image[minor].sem);
+
+ /* XXX Do we *really* want this helper - we can use vme_*_get ? */
+ image_size = vme_get_size(image[minor].resource);
+
+ /* Ensure we are starting at a valid location */
+ if ((*ppos < 0) || (*ppos > (image_size - 1))) {
+ up(&image[minor].sem);
+ return 0;
+ }
+
+ /* Ensure not reading past end of the image */
+ if (*ppos + count > image_size)
+ okcount = image_size - *ppos;
+ else
+ okcount = count;
+
+ switch (type[minor]){
+ case MASTER_MINOR:
+ retval = resource_to_user(minor, buf, okcount, ppos);
+ break;
+ case SLAVE_MINOR:
+ retval = buffer_to_user(minor, buf, okcount, ppos);
+ break;
+ default:
+ retval = -EINVAL;
+ }
+
+ up(&image[minor].sem);
+
+ if (retval > 0)
+ *ppos += retval;
+
+ return retval;
+}
+
+static ssize_t vme_user_write(struct file *file, const char *buf, size_t count,
+ loff_t *ppos)
+{
+ unsigned int minor = MINOR(file->f_dentry->d_inode->i_rdev);
+ ssize_t retval;
+ size_t image_size;
+ size_t okcount;
+
+ down(&image[minor].sem);
+
+ image_size = vme_get_size(image[minor].resource);
+
+ /* Ensure we are starting at a valid location */
+ if ((*ppos < 0) || (*ppos > (image_size - 1))) {
+ up(&image[minor].sem);
+ return 0;
+ }
+
+ /* Ensure not reading past end of the image */
+ if (*ppos + count > image_size)
+ okcount = image_size - *ppos;
+ else
+ okcount = count;
+
+ switch (type[minor]){
+ case MASTER_MINOR:
+ retval = resource_from_user(minor, buf, okcount, ppos);
+ break;
+ case SLAVE_MINOR:
+ retval = buffer_from_user(minor, buf, okcount, ppos);
+ break;
+ default:
+ retval = -EINVAL;
+ }
+
+ up(&image[minor].sem);
+
+ if (retval > 0)
+ *ppos += retval;
+
+ return retval;
+}
+
+static loff_t vme_user_llseek(struct file *file, loff_t off, int whence)
+{
+ printk(KERN_ERR "Llseek currently incomplete\n");
+ return -EINVAL;
+}
+
+static int vme_user_ioctl(struct inode *inode, struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ unsigned int minor = MINOR(inode->i_rdev);
+#if 0
+ int ret_val;
+#endif
+ unsigned long copyRet;
+ vme_slave_t slave;
+
+ statistics.ioctls++;
+ switch (type[minor]) {
+ case CONTROL_MINOR:
+ break;
+ case MASTER_MINOR:
+ break;
+ case SLAVE_MINOR:
+ switch (cmd) {
+ case VME_SET_SLAVE:
+
+ copyRet = copy_from_user(&slave, (char *)arg,
+ sizeof(slave));
+ if (copyRet != 0) {
+ printk(KERN_WARNING "Partial copy from "
+ "userspace\n");
+ return -EFAULT;
+ }
+
+ return vme_slave_set(image[minor].resource,
+ slave.enable, slave.vme_addr, slave.size,
+ image[minor].pci_buf, slave.aspace,
+ slave.cycle);
+
+ break;
+#if 0
+ case VME_GET_SLAVE:
+ vme_slave_t slave;
+
+ ret_val = vme_slave_get(minor, &iRegs);
+
+ copyRet = copy_to_user((char *)arg, &slave,
+ sizeof(slave));
+ if (copyRet != 0) {
+ printk(KERN_WARNING "Partial copy to "
+ "userspace\n");
+ return -EFAULT;
+ }
+
+ return ret_val;
+ break;
+#endif
+ }
+ break;
+ }
+
+ return -EINVAL;
+}
+
+
+/*
+ * Unallocate a previously allocated buffer
+ */
+static void buf_unalloc (int num)
+{
+ if (image[num].kern_buf) {
+#ifdef VME_DEBUG
+ printk(KERN_DEBUG "UniverseII:Releasing buffer at %p\n",
+ image[num].pci_buf);
+#endif
+
+ vme_free_consistent(image[num].resource, image[num].size_buf,
+ image[num].kern_buf, image[num].pci_buf);
+
+ image[num].kern_buf = NULL;
+ image[num].pci_buf = 0;
+ image[num].size_buf = 0;
+
+#ifdef VME_DEBUG
+ } else {
+ printk(KERN_DEBUG "UniverseII: Buffer not allocated\n");
+#endif
+ }
+}
+
+static struct vme_driver vme_user_driver = {
+ .name = driver_name,
+ .probe = vme_user_probe,
+};
+
+
+/*
+ * In this simple access driver, the old behaviour is being preserved as much
+ * as practical. We will therefore reserve the buffers and request the images
+ * here so that we don't have to do it later.
+ */
+static int __init vme_bridge_init(void)
+{
+ int retval;
+ printk(KERN_INFO "VME User Space Access Driver\n");
+ printk("vme_user_driver:%p\n", &vme_user_driver);
+ retval = vme_register_driver(&vme_user_driver);
+ printk("vme_register_driver returned %d\n", retval);
+ return retval;
+}
+
+/*
+ * This structure gets passed a device, this should be the device created at
+ * registration.
+ */
+static int __init vme_user_probe(struct device *dev)
+{
+ int i, err;
+ char name[8];
+
+ printk("Running vme_user_probe()\n");
+
+ /* Pointer to the bridge device */
+ vme_user_bridge = dev;
+
+ /* Initialise descriptors */
+ for (i = 0; i < VME_DEVS; i++) {
+ image[i].kern_buf = NULL;
+ image[i].pci_buf = 0;
+ init_MUTEX(&(image[i].sem));
+ image[i].device = NULL;
+ image[i].resource = NULL;
+ image[i].users = 0;
+ }
+
+ /* Initialise statistics counters */
+ reset_counters();
+
+ /* Assign major and minor numbers for the driver */
+ err = register_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS,
+ driver_name);
+ if (err) {
+ printk(KERN_WARNING "%s: Error getting Major Number %d for "
+ "driver.\n", driver_name, VME_MAJOR);
+ goto err_region;
+ }
+
+ /* Register the driver as a char device */
+ vme_user_cdev = cdev_alloc();
+ vme_user_cdev->ops = &vme_user_fops;
+ vme_user_cdev->owner = THIS_MODULE;
+ err = cdev_add(vme_user_cdev, MKDEV(VME_MAJOR, 0), VME_DEVS);
+ if (err) {
+ printk(KERN_WARNING "%s: cdev_all failed\n", driver_name);
+ goto err_char;
+ }
+
+ /* Request slave resources and allocate buffers (128kB wide) */
+ for (i = SLAVE_MINOR; i < (SLAVE_MAX + 1); i++) {
+ /* XXX Need to properly request attributes */
+ image[i].resource = vme_slave_request(vme_user_bridge,
+ VME_A16, VME_SCT);
+ if (image[i].resource == NULL) {
+ printk(KERN_WARNING "Unable to allocate slave "
+ "resource\n");
+ goto err_buf;
+ }
+ image[i].size_buf = PCI_BUF_SIZE;
+ image[i].kern_buf = vme_alloc_consistent(image[i].resource,
+ image[i].size_buf, &(image[i].pci_buf));
+ if (image[i].kern_buf == NULL) {
+ printk(KERN_WARNING "Unable to allocate memory for "
+ "buffer\n");
+ image[i].pci_buf = 0;
+ vme_slave_free(image[i].resource);
+ err = -ENOMEM;
+ goto err_buf;
+ }
+ }
+
+ /*
+ * Request master resources allocate page sized buffers for small
+ * reads and writes
+ */
+ for (i = MASTER_MINOR; i < (MASTER_MAX + 1); i++) {
+ /* XXX Need to properly request attributes */
+ image[i].resource = vme_master_request(vme_user_bridge,
+ VME_A32, VME_SCT, VME_D32);
+ if (image[i].resource == NULL) {
+ printk(KERN_WARNING "Unable to allocate master "
+ "resource\n");
+ goto err_buf;
+ }
+ image[i].size_buf = PAGE_SIZE;
+ image[i].kern_buf = vme_alloc_consistent(image[i].resource,
+ image[i].size_buf, &(image[i].pci_buf));
+ if (image[i].kern_buf == NULL) {
+ printk(KERN_WARNING "Unable to allocate memory for "
+ "buffer\n");
+ image[i].pci_buf = 0;
+ vme_master_free(image[i].resource);
+ err = -ENOMEM;
+ goto err_buf;
+ }
+ }
+
+ /* Setup some debug windows */
+ for (i = SLAVE_MINOR; i < (SLAVE_MAX + 1); i++) {
+ err = vme_slave_set(image[i].resource, 1, 0x4000*(i-4),
+ 0x4000, image[i].pci_buf, VME_A16,
+ VME_SCT | VME_SUPER | VME_USER | VME_PROG | VME_DATA);
+ if (err != 0) {
+ printk(KERN_WARNING "Failed to configure window\n");
+ goto err_buf;
+ }
+ }
+ for (i = MASTER_MINOR; i < (MASTER_MAX + 1); i++) {
+ err = vme_master_set(image[i].resource, 1,
+ (0x10000 + (0x10000*i)), 0x10000,
+ VME_A32, VME_SCT | VME_USER | VME_DATA, VME_D32);
+ if (err != 0) {
+ printk(KERN_WARNING "Failed to configure window\n");
+ goto err_buf;
+ }
+ }
+
+ /* Create sysfs entries - on udev systems this creates the dev files */
+ vme_user_sysfs_class = class_create(THIS_MODULE, driver_name);
+ if (IS_ERR(vme_user_sysfs_class)) {
+ printk(KERN_ERR "Error creating vme_user class.\n");
+ err = PTR_ERR(vme_user_sysfs_class);
+ goto err_class;
+ }
+
+ /* Add sysfs Entries */
+ for (i=0; i<VME_DEVS; i++) {
+ switch (type[i]) {
+ case MASTER_MINOR:
+ sprintf(name,"bus/vme/m%%d");
+ break;
+ case CONTROL_MINOR:
+ sprintf(name,"bus/vme/ctl");
+ break;
+ case SLAVE_MINOR:
+ sprintf(name,"bus/vme/s%%d");
+ break;
+ default:
+ err = -EINVAL;
+ goto err_sysfs;
+ break;
+ }
+
+ image[i].device =
+ device_create(vme_user_sysfs_class, NULL,
+ MKDEV(VME_MAJOR, i), NULL, name,
+ (type[i] == SLAVE_MINOR)? i - (MASTER_MAX + 1) : i);
+ if (IS_ERR(image[i].device)) {
+ printk("%s: Error creating sysfs device\n",
+ driver_name);
+ err = PTR_ERR(image[i].device);
+ goto err_sysfs;
+ }
+ }
+
+ /* XXX Run tests */
+ /*
+ tests();
+ */
+
+ return 0;
+
+ /* Ensure counter set correcty to destroy all sysfs devices */
+ i = VME_DEVS;
+err_sysfs:
+ while (i > 0){
+ i--;
+ device_destroy(vme_user_sysfs_class, MKDEV(VME_MAJOR, i));
+ }
+ class_destroy(vme_user_sysfs_class);
+
+ /* Ensure counter set correcty to unalloc all slave buffers */
+ i = SLAVE_MAX + 1;
+err_buf:
+ while (i > SLAVE_MINOR){
+ i--;
+ vme_slave_set(image[i].resource, 0, 0, 0, 0, VME_A32, 0);
+ vme_slave_free(image[i].resource);
+ buf_unalloc(i);
+ }
+err_class:
+ cdev_del(vme_user_cdev);
+err_char:
+ unregister_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS);
+err_region:
+ return err;
+}
+
+static void __exit vme_bridge_exit(void)
+{
+ int i;
+
+ /* Remove sysfs Entries */
+ for(i=0; i<VME_DEVS; i++) {
+ device_destroy(vme_user_sysfs_class, MKDEV(VME_MAJOR, i));
+ }
+ class_destroy(vme_user_sysfs_class);
+
+ for (i = SLAVE_MINOR; i < (SLAVE_MAX + 1); i++) {
+ buf_unalloc(i);
+ }
+
+ /* Unregister device driver */
+ cdev_del(vme_user_cdev);
+
+ /* Unregiser the major and minor device numbers */
+ unregister_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS);
+}
+
+MODULE_DESCRIPTION("VME User Space Access Driver");
+MODULE_AUTHOR("Martyn Welch <martyn.welch@gefanuc.com");
+MODULE_LICENSE("GPL");
+
+module_init(vme_bridge_init);
+module_exit(vme_bridge_exit);