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