drivers/staging/vme/devices/vme_user.c

   1 /*
   2  * VMEbus User access driver
   3  *
   4  * Author: Martyn Welch <martyn.welch@ge.com>
   5  * Copyright 2008 GE Intelligent Platforms Embedded Systems, Inc.
   6  *
   7  * Based on work by:
   8  *   Tom Armistead and Ajit Prem
   9  *     Copyright 2004 Motorola Inc.
  10  *
  11  *
  12  * This program is free software; you can redistribute  it and/or modify it
  13  * under  the terms of  the GNU General  Public License as published by the
  14  * Free Software Foundation;  either version 2 of the  License, or (at your
  15  * option) any later version.
  16  */
  17
  18 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  19
  20 #include <linux/refcount.h>
  21 #include <linux/cdev.h>
  22 #include <linux/delay.h>
  23 #include <linux/device.h>
  24 #include <linux/dma-mapping.h>
  25 #include <linux/errno.h>
  26 #include <linux/init.h>
  27 #include <linux/ioctl.h>
  28 #include <linux/kernel.h>
  29 #include <linux/mm.h>
  30 #include <linux/module.h>
  31 #include <linux/pagemap.h>
  32 #include <linux/pci.h>
  33 #include <linux/mutex.h>
  34 #include <linux/slab.h>
  35 #include <linux/spinlock.h>
  36 #include <linux/syscalls.h>
  37 #include <linux/types.h>
  38
  39 #include <linux/io.h>
  40 #include <linux/uaccess.h>
  41 #include <linux/vme.h>
  42
  43 #include "vme_user.h"
  44
  45 static const char driver_name[] = "vme_user";
  46
  47 static int bus[VME_USER_BUS_MAX];
  48 static unsigned int bus_num;
  49
  50 /* Currently Documentation/admin-guide/devices.rst defines the
  51  * following for VME:
  52  *
  53  * 221 char     VME bus
  54  *                0 = /dev/bus/vme/m0           First master image
  55  *                1 = /dev/bus/vme/m1           Second master image
  56  *                2 = /dev/bus/vme/m2           Third master image
  57  *                3 = /dev/bus/vme/m3           Fourth master image
  58  *                4 = /dev/bus/vme/s0           First slave image
  59  *                5 = /dev/bus/vme/s1           Second slave image
  60  *                6 = /dev/bus/vme/s2           Third slave image
  61  *                7 = /dev/bus/vme/s3           Fourth slave image
  62  *                8 = /dev/bus/vme/ctl          Control
  63  *
  64  *              It is expected that all VME bus drivers will use the
  65  *              same interface.  For interface documentation see
  66  *              http://www.vmelinux.org/.
  67  *
  68  * However the VME driver at http://www.vmelinux.org/ is rather old and doesn't
  69  * even support the tsi148 chipset (which has 8 master and 8 slave windows).
  70  * We'll run with this for now as far as possible, however it probably makes
  71  * sense to get rid of the old mappings and just do everything dynamically.
  72  *
  73  * So for now, we'll restrict the driver to providing 4 masters and 4 slaves as
  74  * defined above and try to support at least some of the interface from
  75  * http://www.vmelinux.org/ as an alternative the driver can be written
  76  * providing a saner interface later.
  77  *
  78  * The vmelinux.org driver never supported slave images, the devices reserved
  79  * for slaves were repurposed to support all 8 master images on the UniverseII!
  80  * We shall support 4 masters and 4 slaves with this driver.
  81  */
  82 #define VME_MAJOR       221     /* VME Major Device Number */
  83 #define VME_DEVS        9       /* Number of dev entries */
  84
  85 #define MASTER_MINOR    0
  86 #define MASTER_MAX      3
  87 #define SLAVE_MINOR     4
  88 #define SLAVE_MAX       7
  89 #define CONTROL_MINOR   8
  90
  91 #define PCI_BUF_SIZE  0x20000   /* Size of one slave image buffer */
  92
  93 /*
  94  * Structure to handle image related parameters.
  95  */
  96 struct image_desc {
  97         void *kern_buf; /* Buffer address in kernel space */
  98         dma_addr_t pci_buf;     /* Buffer address in PCI address space */
  99         unsigned long long size_buf;    /* Buffer size */
 100         struct mutex mutex;     /* Mutex for locking image */
 101         struct device *device;  /* Sysfs device */
 102         struct vme_resource *resource;  /* VME resource */
 103         int mmap_count;         /* Number of current mmap's */
 104 };
 105
 106 static struct image_desc image[VME_DEVS];
 107
 108 static struct cdev *vme_user_cdev;              /* Character device */
 109 static struct class *vme_user_sysfs_class;      /* Sysfs class */
 110 static struct vme_dev *vme_user_bridge;         /* Pointer to user device */
 111
 112 static const int type[VME_DEVS] = {     MASTER_MINOR,   MASTER_MINOR,
 113                                         MASTER_MINOR,   MASTER_MINOR,
 114                                         SLAVE_MINOR,    SLAVE_MINOR,
 115                                         SLAVE_MINOR,    SLAVE_MINOR,
 116                                         CONTROL_MINOR
 117                                 };
 118
 119 struct vme_user_vma_priv {
 120         unsigned int minor;
 121         refcount_t refcnt;
 122 };
 123
 124 static ssize_t resource_to_user(int minor, char __user *buf, size_t count,
 125                                 loff_t *ppos)
 126 {
 127         ssize_t copied = 0;
 128
 129         if (count > image[minor].size_buf)
 130                 count = image[minor].size_buf;
 131
 132         copied = vme_master_read(image[minor].resource, image[minor].kern_buf,
 133                                  count, *ppos);
 134         if (copied < 0)
 135                 return (int)copied;
 136
 137         if (__copy_to_user(buf, image[minor].kern_buf, (unsigned long)copied))
 138                 return -EFAULT;
 139
 140         return copied;
 141 }
 142
 143 static ssize_t resource_from_user(unsigned int minor, const char __user *buf,
 144                                   size_t count, loff_t *ppos)
 145 {
 146         if (count > image[minor].size_buf)
 147                 count = image[minor].size_buf;
 148
 149         if (__copy_from_user(image[minor].kern_buf, buf, (unsigned long)count))
 150                 return -EFAULT;
 151
 152         return vme_master_write(image[minor].resource, image[minor].kern_buf,
 153                                 count, *ppos);
 154 }
 155
 156 static ssize_t buffer_to_user(unsigned int minor, char __user *buf,
 157                               size_t count, loff_t *ppos)
 158 {
 159         void *image_ptr;
 160
 161         image_ptr = image[minor].kern_buf + *ppos;
 162         if (__copy_to_user(buf, image_ptr, (unsigned long)count))
 163                 return -EFAULT;
 164
 165         return count;
 166 }
 167
 168 static ssize_t buffer_from_user(unsigned int minor, const char __user *buf,
 169                                 size_t count, loff_t *ppos)
 170 {
 171         void *image_ptr;
 172
 173         image_ptr = image[minor].kern_buf + *ppos;
 174         if (__copy_from_user(image_ptr, buf, (unsigned long)count))
 175                 return -EFAULT;
 176
 177         return count;
 178 }
 179
 180 static ssize_t vme_user_read(struct file *file, char __user *buf, size_t count,
 181                              loff_t *ppos)
 182 {
 183         unsigned int minor = MINOR(file_inode(file)->i_rdev);
 184         ssize_t retval;
 185         size_t image_size;
 186
 187         if (minor == CONTROL_MINOR)
 188                 return 0;
 189
 190         mutex_lock(&image[minor].mutex);
 191
 192         /* XXX Do we *really* want this helper - we can use vme_*_get ? */
 193         image_size = vme_get_size(image[minor].resource);
 194
 195         /* Ensure we are starting at a valid location */
 196         if ((*ppos < 0) || (*ppos > (image_size - 1))) {
 197                 mutex_unlock(&image[minor].mutex);
 198                 return 0;
 199         }
 200
 201         /* Ensure not reading past end of the image */
 202         if (*ppos + count > image_size)
 203                 count = image_size - *ppos;
 204
 205         switch (type[minor]) {
 206         case MASTER_MINOR:
 207                 retval = resource_to_user(minor, buf, count, ppos);
 208                 break;
 209         case SLAVE_MINOR:
 210                 retval = buffer_to_user(minor, buf, count, ppos);
 211                 break;
 212         default:
 213                 retval = -EINVAL;
 214         }
 215
 216         mutex_unlock(&image[minor].mutex);
 217         if (retval > 0)
 218                 *ppos += retval;
 219
 220         return retval;
 221 }
 222
 223 static ssize_t vme_user_write(struct file *file, const char __user *buf,
 224                               size_t count, loff_t *ppos)
 225 {
 226         unsigned int minor = MINOR(file_inode(file)->i_rdev);
 227         ssize_t retval;
 228         size_t image_size;
 229
 230         if (minor == CONTROL_MINOR)
 231                 return 0;
 232
 233         mutex_lock(&image[minor].mutex);
 234
 235         image_size = vme_get_size(image[minor].resource);
 236
 237         /* Ensure we are starting at a valid location */
 238         if ((*ppos < 0) || (*ppos > (image_size - 1))) {
 239                 mutex_unlock(&image[minor].mutex);
 240                 return 0;
 241         }
 242
 243         /* Ensure not reading past end of the image */
 244         if (*ppos + count > image_size)
 245                 count = image_size - *ppos;
 246
 247         switch (type[minor]) {
 248         case MASTER_MINOR:
 249                 retval = resource_from_user(minor, buf, count, ppos);
 250                 break;
 251         case SLAVE_MINOR:
 252                 retval = buffer_from_user(minor, buf, count, ppos);
 253                 break;
 254         default:
 255                 retval = -EINVAL;
 256         }
 257
 258         mutex_unlock(&image[minor].mutex);
 259
 260         if (retval > 0)
 261                 *ppos += retval;
 262
 263         return retval;
 264 }
 265
 266 static loff_t vme_user_llseek(struct file *file, loff_t off, int whence)
 267 {
 268         unsigned int minor = MINOR(file_inode(file)->i_rdev);
 269         size_t image_size;
 270         loff_t res;
 271
 272         switch (type[minor]) {
 273         case MASTER_MINOR:
 274         case SLAVE_MINOR:
 275                 mutex_lock(&image[minor].mutex);
 276                 image_size = vme_get_size(image[minor].resource);
 277                 res = fixed_size_llseek(file, off, whence, image_size);
 278                 mutex_unlock(&image[minor].mutex);
 279                 return res;
 280         }
 281
 282         return -EINVAL;
 283 }
 284
 285 /*
 286  * The ioctls provided by the old VME access method (the one at vmelinux.org)
 287  * are most certainly wrong as the effectively push the registers layout
 288  * through to user space. Given that the VME core can handle multiple bridges,
 289  * with different register layouts this is most certainly not the way to go.
 290  *
 291  * We aren't using the structures defined in the Motorola driver either - these
 292  * are also quite low level, however we should use the definitions that have
 293  * already been defined.
 294  */
 295 static int vme_user_ioctl(struct inode *inode, struct file *file,
 296                           unsigned int cmd, unsigned long arg)
 297 {
 298         struct vme_master master;
 299         struct vme_slave slave;
 300         struct vme_irq_id irq_req;
 301         unsigned long copied;
 302         unsigned int minor = MINOR(inode->i_rdev);
 303         int retval;
 304         dma_addr_t pci_addr;
 305         void __user *argp = (void __user *)arg;
 306
 307         switch (type[minor]) {
 308         case CONTROL_MINOR:
 309                 switch (cmd) {
 310                 case VME_IRQ_GEN:
 311                         copied = copy_from_user(&irq_req, argp,
 312                                                 sizeof(irq_req));
 313                         if (copied) {
 314                                 pr_warn("Partial copy from userspace\n");
 315                                 return -EFAULT;
 316                         }
 317
 318                         return vme_irq_generate(vme_user_bridge,
 319                                                   irq_req.level,
 320                                                   irq_req.statid);
 321                 }
 322                 break;
 323         case MASTER_MINOR:
 324                 switch (cmd) {
 325                 case VME_GET_MASTER:
 326                         memset(&master, 0, sizeof(master));
 327
 328                         /* XXX  We do not want to push aspace, cycle and width
 329                          *      to userspace as they are
 330                          */
 331                         retval = vme_master_get(image[minor].resource,
 332                                                 &master.enable,
 333                                                 &master.vme_addr,
 334                                                 &master.size, &master.aspace,
 335                                                 &master.cycle, &master.dwidth);
 336
 337                         copied = copy_to_user(argp, &master,
 338                                               sizeof(master));
 339                         if (copied) {
 340                                 pr_warn("Partial copy to userspace\n");
 341                                 return -EFAULT;
 342                         }
 343
 344                         return retval;
 345
 346                 case VME_SET_MASTER:
 347
 348                         if (image[minor].mmap_count != 0) {
 349                                 pr_warn("Can't adjust mapped window\n");
 350                                 return -EPERM;
 351                         }
 352
 353                         copied = copy_from_user(&master, argp, sizeof(master));
 354                         if (copied) {
 355                                 pr_warn("Partial copy from userspace\n");
 356                                 return -EFAULT;
 357                         }
 358
 359                         /* XXX  We do not want to push aspace, cycle and width
 360                          *      to userspace as they are
 361                          */
 362                         return vme_master_set(image[minor].resource,
 363                                 master.enable, master.vme_addr, master.size,
 364                                 master.aspace, master.cycle, master.dwidth);
 365
 366                         break;
 367                 }
 368                 break;
 369         case SLAVE_MINOR:
 370                 switch (cmd) {
 371                 case VME_GET_SLAVE:
 372                         memset(&slave, 0, sizeof(slave));
 373
 374                         /* XXX  We do not want to push aspace, cycle and width
 375                          *      to userspace as they are
 376                          */
 377                         retval = vme_slave_get(image[minor].resource,
 378                                                &slave.enable, &slave.vme_addr,
 379                                                &slave.size, &pci_addr,
 380                                                &slave.aspace, &slave.cycle);
 381
 382                         copied = copy_to_user(argp, &slave,
 383                                               sizeof(slave));
 384                         if (copied) {
 385                                 pr_warn("Partial copy to userspace\n");
 386                                 return -EFAULT;
 387                         }
 388
 389                         return retval;
 390
 391                 case VME_SET_SLAVE:
 392
 393                         copied = copy_from_user(&slave, argp, sizeof(slave));
 394                         if (copied) {
 395                                 pr_warn("Partial copy from userspace\n");
 396                                 return -EFAULT;
 397                         }
 398
 399                         /* XXX  We do not want to push aspace, cycle and width
 400                          *      to userspace as they are
 401                          */
 402                         return vme_slave_set(image[minor].resource,
 403                                 slave.enable, slave.vme_addr, slave.size,
 404                                 image[minor].pci_buf, slave.aspace,
 405                                 slave.cycle);
 406
 407                         break;
 408                 }
 409                 break;
 410         }
 411
 412         return -EINVAL;
 413 }
 414
 415 static long
 416 vme_user_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 417 {
 418         int ret;
 419         struct inode *inode = file_inode(file);
 420         unsigned int minor = MINOR(inode->i_rdev);
 421
 422         mutex_lock(&image[minor].mutex);
 423         ret = vme_user_ioctl(inode, file, cmd, arg);
 424         mutex_unlock(&image[minor].mutex);
 425
 426         return ret;
 427 }
 428
 429 static void vme_user_vm_open(struct vm_area_struct *vma)
 430 {
 431         struct vme_user_vma_priv *vma_priv = vma->vm_private_data;
 432
 433         refcount_inc(&vma_priv->refcnt);
 434 }
 435
 436 static void vme_user_vm_close(struct vm_area_struct *vma)
 437 {
 438         struct vme_user_vma_priv *vma_priv = vma->vm_private_data;
 439         unsigned int minor = vma_priv->minor;
 440
 441         if (!refcount_dec_and_test(&vma_priv->refcnt))
 442                 return;
 443
 444         mutex_lock(&image[minor].mutex);
 445         image[minor].mmap_count--;
 446         mutex_unlock(&image[minor].mutex);
 447
 448         kfree(vma_priv);
 449 }
 450
 451 static const struct vm_operations_struct vme_user_vm_ops = {
 452         .open = vme_user_vm_open,
 453         .close = vme_user_vm_close,
 454 };
 455
 456 static int vme_user_master_mmap(unsigned int minor, struct vm_area_struct *vma)
 457 {
 458         int err;
 459         struct vme_user_vma_priv *vma_priv;
 460
 461         mutex_lock(&image[minor].mutex);
 462
 463         err = vme_master_mmap(image[minor].resource, vma);
 464         if (err) {
 465                 mutex_unlock(&image[minor].mutex);
 466                 return err;
 467         }
 468
 469         vma_priv = kmalloc(sizeof(*vma_priv), GFP_KERNEL);
 470         if (!vma_priv) {
 471                 mutex_unlock(&image[minor].mutex);
 472                 return -ENOMEM;
 473         }
 474
 475         vma_priv->minor = minor;
 476         refcount_set(&vma_priv->refcnt, 1);
 477         vma->vm_ops = &vme_user_vm_ops;
 478         vma->vm_private_data = vma_priv;
 479
 480         image[minor].mmap_count++;
 481
 482         mutex_unlock(&image[minor].mutex);
 483
 484         return 0;
 485 }
 486
 487 static int vme_user_mmap(struct file *file, struct vm_area_struct *vma)
 488 {
 489         unsigned int minor = MINOR(file_inode(file)->i_rdev);
 490
 491         if (type[minor] == MASTER_MINOR)
 492                 return vme_user_master_mmap(minor, vma);
 493
 494         return -ENODEV;
 495 }
 496
 497 static const struct file_operations vme_user_fops = {
 498         .read = vme_user_read,
 499         .write = vme_user_write,
 500         .llseek = vme_user_llseek,
 501         .unlocked_ioctl = vme_user_unlocked_ioctl,
 502         .compat_ioctl = vme_user_unlocked_ioctl,
 503         .mmap = vme_user_mmap,
 504 };
 505
 506 static int vme_user_match(struct vme_dev *vdev)
 507 {
 508         int i;
 509
 510         int cur_bus = vme_bus_num(vdev);
 511         int cur_slot = vme_slot_num(vdev);
 512
 513         for (i = 0; i < bus_num; i++)
 514                 if ((cur_bus == bus[i]) && (cur_slot == vdev->num))
 515                         return 1;
 516
 517         return 0;
 518 }
 519
 520 /*
 521  * In this simple access driver, the old behaviour is being preserved as much
 522  * as practical. We will therefore reserve the buffers and request the images
 523  * here so that we don't have to do it later.
 524  */
 525 static int vme_user_probe(struct vme_dev *vdev)
 526 {
 527         int i, err;
 528         char *name;
 529
 530         /* Save pointer to the bridge device */
 531         if (vme_user_bridge) {
 532                 dev_err(&vdev->dev, "Driver can only be loaded for 1 device\n");
 533                 err = -EINVAL;
 534                 goto err_dev;
 535         }
 536         vme_user_bridge = vdev;
 537
 538         /* Initialise descriptors */
 539         for (i = 0; i < VME_DEVS; i++) {
 540                 image[i].kern_buf = NULL;
 541                 image[i].pci_buf = 0;
 542                 mutex_init(&image[i].mutex);
 543                 image[i].device = NULL;
 544                 image[i].resource = NULL;
 545         }
 546
 547         /* Assign major and minor numbers for the driver */
 548         err = register_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS,
 549                                      driver_name);
 550         if (err) {
 551                 dev_warn(&vdev->dev, "Error getting Major Number %d for driver.\n",
 552                          VME_MAJOR);
 553                 goto err_region;
 554         }
 555
 556         /* Register the driver as a char device */
 557         vme_user_cdev = cdev_alloc();
 558         if (!vme_user_cdev) {
 559                 err = -ENOMEM;
 560                 goto err_char;
 561         }
 562         vme_user_cdev->ops = &vme_user_fops;
 563         vme_user_cdev->owner = THIS_MODULE;
 564         err = cdev_add(vme_user_cdev, MKDEV(VME_MAJOR, 0), VME_DEVS);
 565         if (err)
 566                 goto err_char;
 567
 568         /* Request slave resources and allocate buffers (128kB wide) */
 569         for (i = SLAVE_MINOR; i < (SLAVE_MAX + 1); i++) {
 570                 /* XXX Need to properly request attributes */
 571                 /* For ca91cx42 bridge there are only two slave windows
 572                  * supporting A16 addressing, so we request A24 supported
 573                  * by all windows.
 574                  */
 575                 image[i].resource = vme_slave_request(vme_user_bridge,
 576                         VME_A24, VME_SCT);
 577                 if (!image[i].resource) {
 578                         dev_warn(&vdev->dev,
 579                                  "Unable to allocate slave resource\n");
 580                         err = -ENOMEM;
 581                         goto err_slave;
 582                 }
 583                 image[i].size_buf = PCI_BUF_SIZE;
 584                 image[i].kern_buf = vme_alloc_consistent(image[i].resource,
 585                         image[i].size_buf, &image[i].pci_buf);
 586                 if (!image[i].kern_buf) {
 587                         dev_warn(&vdev->dev,
 588                                  "Unable to allocate memory for buffer\n");
 589                         image[i].pci_buf = 0;
 590                         vme_slave_free(image[i].resource);
 591                         err = -ENOMEM;
 592                         goto err_slave;
 593                 }
 594         }
 595
 596         /*
 597          * Request master resources allocate page sized buffers for small
 598          * reads and writes
 599          */
 600         for (i = MASTER_MINOR; i < (MASTER_MAX + 1); i++) {
 601                 /* XXX Need to properly request attributes */
 602                 image[i].resource = vme_master_request(vme_user_bridge,
 603                         VME_A32, VME_SCT, VME_D32);
 604                 if (!image[i].resource) {
 605                         dev_warn(&vdev->dev,
 606                                  "Unable to allocate master resource\n");
 607                         err = -ENOMEM;
 608                         goto err_master;
 609                 }
 610                 image[i].size_buf = PCI_BUF_SIZE;
 611                 image[i].kern_buf = kmalloc(image[i].size_buf, GFP_KERNEL);
 612                 if (!image[i].kern_buf) {
 613                         err = -ENOMEM;
 614                         vme_master_free(image[i].resource);
 615                         goto err_master;
 616                 }
 617         }
 618
 619         /* Create sysfs entries - on udev systems this creates the dev files */
 620         vme_user_sysfs_class = class_create(THIS_MODULE, driver_name);
 621         if (IS_ERR(vme_user_sysfs_class)) {
 622                 dev_err(&vdev->dev, "Error creating vme_user class.\n");
 623                 err = PTR_ERR(vme_user_sysfs_class);
 624                 goto err_class;
 625         }
 626
 627         /* Add sysfs Entries */
 628         for (i = 0; i < VME_DEVS; i++) {
 629                 int num;
 630
 631                 switch (type[i]) {
 632                 case MASTER_MINOR:
 633                         name = "bus/vme/m%d";
 634                         break;
 635                 case CONTROL_MINOR:
 636                         name = "bus/vme/ctl";
 637                         break;
 638                 case SLAVE_MINOR:
 639                         name = "bus/vme/s%d";
 640                         break;
 641                 default:
 642                         err = -EINVAL;
 643                         goto err_sysfs;
 644                 }
 645
 646                 num = (type[i] == SLAVE_MINOR) ? i - (MASTER_MAX + 1) : i;
 647                 image[i].device = device_create(vme_user_sysfs_class, NULL,
 648                                         MKDEV(VME_MAJOR, i), NULL, name, num);
 649                 if (IS_ERR(image[i].device)) {
 650                         dev_info(&vdev->dev, "Error creating sysfs device\n");
 651                         err = PTR_ERR(image[i].device);
 652                         goto err_sysfs;
 653                 }
 654         }
 655
 656         return 0;
 657
 658 err_sysfs:
 659         while (i > 0) {
 660                 i--;
 661                 device_destroy(vme_user_sysfs_class, MKDEV(VME_MAJOR, i));
 662         }
 663         class_destroy(vme_user_sysfs_class);
 664
 665         /* Ensure counter set correctly to unalloc all master windows */
 666         i = MASTER_MAX + 1;
 667 err_master:
 668         while (i > MASTER_MINOR) {
 669                 i--;
 670                 kfree(image[i].kern_buf);
 671                 vme_master_free(image[i].resource);
 672         }
 673
 674         /*
 675          * Ensure counter set correctly to unalloc all slave windows and buffers
 676          */
 677         i = SLAVE_MAX + 1;
 678 err_slave:
 679         while (i > SLAVE_MINOR) {
 680                 i--;
 681                 vme_free_consistent(image[i].resource, image[i].size_buf,
 682                                     image[i].kern_buf, image[i].pci_buf);
 683                 vme_slave_free(image[i].resource);
 684         }
 685 err_class:
 686         cdev_del(vme_user_cdev);
 687 err_char:
 688         unregister_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS);
 689 err_region:
 690 err_dev:
 691         return err;
 692 }
 693
 694 static int vme_user_remove(struct vme_dev *dev)
 695 {
 696         int i;
 697
 698         /* Remove sysfs Entries */
 699         for (i = 0; i < VME_DEVS; i++) {
 700                 mutex_destroy(&image[i].mutex);
 701                 device_destroy(vme_user_sysfs_class, MKDEV(VME_MAJOR, i));
 702         }
 703         class_destroy(vme_user_sysfs_class);
 704
 705         for (i = MASTER_MINOR; i < (MASTER_MAX + 1); i++) {
 706                 kfree(image[i].kern_buf);
 707                 vme_master_free(image[i].resource);
 708         }
 709
 710         for (i = SLAVE_MINOR; i < (SLAVE_MAX + 1); i++) {
 711                 vme_slave_set(image[i].resource, 0, 0, 0, 0, VME_A32, 0);
 712                 vme_free_consistent(image[i].resource, image[i].size_buf,
 713                                     image[i].kern_buf, image[i].pci_buf);
 714                 vme_slave_free(image[i].resource);
 715         }
 716
 717         /* Unregister device driver */
 718         cdev_del(vme_user_cdev);
 719
 720         /* Unregister the major and minor device numbers */
 721         unregister_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS);
 722
 723         return 0;
 724 }
 725
 726 static struct vme_driver vme_user_driver = {
 727         .name = driver_name,
 728         .match = vme_user_match,
 729         .probe = vme_user_probe,
 730         .remove = vme_user_remove,
 731 };
 732
 733 static int __init vme_user_init(void)
 734 {
 735         int retval = 0;
 736
 737         pr_info("VME User Space Access Driver\n");
 738
 739         if (bus_num == 0) {
 740                 pr_err("No cards, skipping registration\n");
 741                 retval = -ENODEV;
 742                 goto err_nocard;
 743         }
 744
 745         /* Let's start by supporting one bus, we can support more than one
 746          * in future revisions if that ever becomes necessary.
 747          */
 748         if (bus_num > VME_USER_BUS_MAX) {
 749                 pr_err("Driver only able to handle %d buses\n",
 750                        VME_USER_BUS_MAX);
 751                 bus_num = VME_USER_BUS_MAX;
 752         }
 753
 754         /*
 755          * Here we just register the maximum number of devices we can and
 756          * leave vme_user_match() to allow only 1 to go through to probe().
 757          * This way, if we later want to allow multiple user access devices,
 758          * we just change the code in vme_user_match().
 759          */
 760         retval = vme_register_driver(&vme_user_driver, VME_MAX_SLOTS);
 761         if (retval)
 762                 goto err_reg;
 763
 764         return retval;
 765
 766 err_reg:
 767 err_nocard:
 768         return retval;
 769 }
 770
 771 static void __exit vme_user_exit(void)
 772 {
 773         vme_unregister_driver(&vme_user_driver);
 774 }
 775
 776 MODULE_PARM_DESC(bus, "Enumeration of VMEbus to which the driver is connected");
 777 module_param_array(bus, int, &bus_num, 0000);
 778
 779 MODULE_DESCRIPTION("VME User Space Access Driver");
 780 MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com");
 781 MODULE_LICENSE("GPL");
 782
 783 module_init(vme_user_init);
 784 module_exit(vme_user_exit);