drivers/staging/vme/devices/vme_user.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * VMEbus User access driver
   4  *
   5  * Author: Martyn Welch <martyn.welch@ge.com>
   6  * Copyright 2008 GE Intelligent Platforms Embedded Systems, Inc.
   7  *
   8  * Based on work by:
   9  *   Tom Armistead and Ajit Prem
  10  *     Copyright 2004 Motorola Inc.
  11  */
  12
  13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  14
  15 #include <linux/refcount.h>
  16 #include <linux/cdev.h>
  17 #include <linux/delay.h>
  18 #include <linux/device.h>
  19 #include <linux/dma-mapping.h>
  20 #include <linux/errno.h>
  21 #include <linux/init.h>
  22 #include <linux/ioctl.h>
  23 #include <linux/kernel.h>
  24 #include <linux/mm.h>
  25 #include <linux/module.h>
  26 #include <linux/pagemap.h>
  27 #include <linux/pci.h>
  28 #include <linux/mutex.h>
  29 #include <linux/slab.h>
  30 #include <linux/spinlock.h>
  31 #include <linux/syscalls.h>
  32 #include <linux/types.h>
  33
  34 #include <linux/io.h>
  35 #include <linux/uaccess.h>
  36 #include <linux/vme.h>
  37
  38 #include "vme_user.h"
  39
  40 static const char driver_name[] = "vme_user";
  41
  42 static int bus[VME_USER_BUS_MAX];
  43 static unsigned int bus_num;
  44
  45 /* Currently Documentation/admin-guide/devices.rst defines the
  46  * following for VME:
  47  *
  48  * 221 char     VME bus
  49  *                0 = /dev/bus/vme/m0           First master image
  50  *                1 = /dev/bus/vme/m1           Second master image
  51  *                2 = /dev/bus/vme/m2           Third master image
  52  *                3 = /dev/bus/vme/m3           Fourth master image
  53  *                4 = /dev/bus/vme/s0           First slave image
  54  *                5 = /dev/bus/vme/s1           Second slave image
  55  *                6 = /dev/bus/vme/s2           Third slave image
  56  *                7 = /dev/bus/vme/s3           Fourth slave image
  57  *                8 = /dev/bus/vme/ctl          Control
  58  *
  59  *              It is expected that all VME bus drivers will use the
  60  *              same interface.  For interface documentation see
  61  *              http://www.vmelinux.org/.
  62  *
  63  * However the VME driver at http://www.vmelinux.org/ is rather old and doesn't
  64  * even support the tsi148 chipset (which has 8 master and 8 slave windows).
  65  * We'll run with this for now as far as possible, however it probably makes
  66  * sense to get rid of the old mappings and just do everything dynamically.
  67  *
  68  * So for now, we'll restrict the driver to providing 4 masters and 4 slaves as
  69  * defined above and try to support at least some of the interface from
  70  * http://www.vmelinux.org/ as an alternative the driver can be written
  71  * providing a saner interface later.
  72  *
  73  * The vmelinux.org driver never supported slave images, the devices reserved
  74  * for slaves were repurposed to support all 8 master images on the UniverseII!
  75  * We shall support 4 masters and 4 slaves with this driver.
  76  */
  77 #define VME_MAJOR       221     /* VME Major Device Number */
  78 #define VME_DEVS        9       /* Number of dev entries */
  79
  80 #define MASTER_MINOR    0
  81 #define MASTER_MAX      3
  82 #define SLAVE_MINOR     4
  83 #define SLAVE_MAX       7
  84 #define CONTROL_MINOR   8
  85
  86 #define PCI_BUF_SIZE  0x20000   /* Size of one slave image buffer */
  87
  88 /*
  89  * Structure to handle image related parameters.
  90  */
  91 struct image_desc {
  92         void *kern_buf; /* Buffer address in kernel space */
  93         dma_addr_t pci_buf;     /* Buffer address in PCI address space */
  94         unsigned long long size_buf;    /* Buffer size */
  95         struct mutex mutex;     /* Mutex for locking image */
  96         struct device *device;  /* Sysfs device */
  97         struct vme_resource *resource;  /* VME resource */
  98         int mmap_count;         /* Number of current mmap's */
  99 };
 100
 101 static struct image_desc image[VME_DEVS];
 102
 103 static struct cdev *vme_user_cdev;              /* Character device */
 104 static struct class *vme_user_sysfs_class;      /* Sysfs class */
 105 static struct vme_dev *vme_user_bridge;         /* Pointer to user device */
 106
 107 static const int type[VME_DEVS] = {     MASTER_MINOR,   MASTER_MINOR,
 108                                         MASTER_MINOR,   MASTER_MINOR,
 109                                         SLAVE_MINOR,    SLAVE_MINOR,
 110                                         SLAVE_MINOR,    SLAVE_MINOR,
 111                                         CONTROL_MINOR
 112                                 };
 113
 114 struct vme_user_vma_priv {
 115         unsigned int minor;
 116         refcount_t refcnt;
 117 };
 118
 119 static ssize_t resource_to_user(int minor, char __user *buf, size_t count,
 120                                 loff_t *ppos)
 121 {
 122         ssize_t copied = 0;
 123
 124         if (count > image[minor].size_buf)
 125                 count = image[minor].size_buf;
 126
 127         copied = vme_master_read(image[minor].resource, image[minor].kern_buf,
 128                                  count, *ppos);
 129         if (copied < 0)
 130                 return (int)copied;
 131
 132         if (copy_to_user(buf, image[minor].kern_buf, (unsigned long)copied))
 133                 return -EFAULT;
 134
 135         return copied;
 136 }
 137
 138 static ssize_t resource_from_user(unsigned int minor, const char __user *buf,
 139                                   size_t count, loff_t *ppos)
 140 {
 141         if (count > image[minor].size_buf)
 142                 count = image[minor].size_buf;
 143
 144         if (copy_from_user(image[minor].kern_buf, buf, (unsigned long)count))
 145                 return -EFAULT;
 146
 147         return vme_master_write(image[minor].resource, image[minor].kern_buf,
 148                                 count, *ppos);
 149 }
 150
 151 static ssize_t buffer_to_user(unsigned int minor, char __user *buf,
 152                               size_t count, loff_t *ppos)
 153 {
 154         void *image_ptr;
 155
 156         image_ptr = image[minor].kern_buf + *ppos;
 157         if (copy_to_user(buf, image_ptr, (unsigned long)count))
 158                 return -EFAULT;
 159
 160         return count;
 161 }
 162
 163 static ssize_t buffer_from_user(unsigned int minor, const char __user *buf,
 164                                 size_t count, loff_t *ppos)
 165 {
 166         void *image_ptr;
 167
 168         image_ptr = image[minor].kern_buf + *ppos;
 169         if (copy_from_user(image_ptr, buf, (unsigned long)count))
 170                 return -EFAULT;
 171
 172         return count;
 173 }
 174
 175 static ssize_t vme_user_read(struct file *file, char __user *buf, size_t count,
 176                              loff_t *ppos)
 177 {
 178         unsigned int minor = MINOR(file_inode(file)->i_rdev);
 179         ssize_t retval;
 180         size_t image_size;
 181
 182         if (minor == CONTROL_MINOR)
 183                 return 0;
 184
 185         mutex_lock(&image[minor].mutex);
 186
 187         /* XXX Do we *really* want this helper - we can use vme_*_get ? */
 188         image_size = vme_get_size(image[minor].resource);
 189
 190         /* Ensure we are starting at a valid location */
 191         if ((*ppos < 0) || (*ppos > (image_size - 1))) {
 192                 mutex_unlock(&image[minor].mutex);
 193                 return 0;
 194         }
 195
 196         /* Ensure not reading past end of the image */
 197         if (*ppos + count > image_size)
 198                 count = image_size - *ppos;
 199
 200         switch (type[minor]) {
 201         case MASTER_MINOR:
 202                 retval = resource_to_user(minor, buf, count, ppos);
 203                 break;
 204         case SLAVE_MINOR:
 205                 retval = buffer_to_user(minor, buf, count, ppos);
 206                 break;
 207         default:
 208                 retval = -EINVAL;
 209         }
 210
 211         mutex_unlock(&image[minor].mutex);
 212         if (retval > 0)
 213                 *ppos += retval;
 214
 215         return retval;
 216 }
 217
 218 static ssize_t vme_user_write(struct file *file, const char __user *buf,
 219                               size_t count, loff_t *ppos)
 220 {
 221         unsigned int minor = MINOR(file_inode(file)->i_rdev);
 222         ssize_t retval;
 223         size_t image_size;
 224
 225         if (minor == CONTROL_MINOR)
 226                 return 0;
 227
 228         mutex_lock(&image[minor].mutex);
 229
 230         image_size = vme_get_size(image[minor].resource);
 231
 232         /* Ensure we are starting at a valid location */
 233         if ((*ppos < 0) || (*ppos > (image_size - 1))) {
 234                 mutex_unlock(&image[minor].mutex);
 235                 return 0;
 236         }
 237
 238         /* Ensure not reading past end of the image */
 239         if (*ppos + count > image_size)
 240                 count = image_size - *ppos;
 241
 242         switch (type[minor]) {
 243         case MASTER_MINOR:
 244                 retval = resource_from_user(minor, buf, count, ppos);
 245                 break;
 246         case SLAVE_MINOR:
 247                 retval = buffer_from_user(minor, buf, count, ppos);
 248                 break;
 249         default:
 250                 retval = -EINVAL;
 251         }
 252
 253         mutex_unlock(&image[minor].mutex);
 254
 255         if (retval > 0)
 256                 *ppos += retval;
 257
 258         return retval;
 259 }
 260
 261 static loff_t vme_user_llseek(struct file *file, loff_t off, int whence)
 262 {
 263         unsigned int minor = MINOR(file_inode(file)->i_rdev);
 264         size_t image_size;
 265         loff_t res;
 266
 267         switch (type[minor]) {
 268         case MASTER_MINOR:
 269         case SLAVE_MINOR:
 270                 mutex_lock(&image[minor].mutex);
 271                 image_size = vme_get_size(image[minor].resource);
 272                 res = fixed_size_llseek(file, off, whence, image_size);
 273                 mutex_unlock(&image[minor].mutex);
 274                 return res;
 275         }
 276
 277         return -EINVAL;
 278 }
 279
 280 /*
 281  * The ioctls provided by the old VME access method (the one at vmelinux.org)
 282  * are most certainly wrong as the effectively push the registers layout
 283  * through to user space. Given that the VME core can handle multiple bridges,
 284  * with different register layouts this is most certainly not the way to go.
 285  *
 286  * We aren't using the structures defined in the Motorola driver either - these
 287  * are also quite low level, however we should use the definitions that have
 288  * already been defined.
 289  */
 290 static int vme_user_ioctl(struct inode *inode, struct file *file,
 291                           unsigned int cmd, unsigned long arg)
 292 {
 293         struct vme_master master;
 294         struct vme_slave slave;
 295         struct vme_irq_id irq_req;
 296         unsigned long copied;
 297         unsigned int minor = MINOR(inode->i_rdev);
 298         int retval;
 299         dma_addr_t pci_addr;
 300         void __user *argp = (void __user *)arg;
 301
 302         switch (type[minor]) {
 303         case CONTROL_MINOR:
 304                 switch (cmd) {
 305                 case VME_IRQ_GEN:
 306                         copied = copy_from_user(&irq_req, argp,
 307                                                 sizeof(irq_req));
 308                         if (copied) {
 309                                 pr_warn("Partial copy from userspace\n");
 310                                 return -EFAULT;
 311                         }
 312
 313                         return vme_irq_generate(vme_user_bridge,
 314                                                   irq_req.level,
 315                                                   irq_req.statid);
 316                 }
 317                 break;
 318         case MASTER_MINOR:
 319                 switch (cmd) {
 320                 case VME_GET_MASTER:
 321                         memset(&master, 0, sizeof(master));
 322
 323                         /* XXX  We do not want to push aspace, cycle and width
 324                          *      to userspace as they are
 325                          */
 326                         retval = vme_master_get(image[minor].resource,
 327                                                 &master.enable,
 328                                                 &master.vme_addr,
 329                                                 &master.size, &master.aspace,
 330                                                 &master.cycle, &master.dwidth);
 331
 332                         copied = copy_to_user(argp, &master,
 333                                               sizeof(master));
 334                         if (copied) {
 335                                 pr_warn("Partial copy to userspace\n");
 336                                 return -EFAULT;
 337                         }
 338
 339                         return retval;
 340
 341                 case VME_SET_MASTER:
 342
 343                         if (image[minor].mmap_count != 0) {
 344                                 pr_warn("Can't adjust mapped window\n");
 345                                 return -EPERM;
 346                         }
 347
 348                         copied = copy_from_user(&master, argp, sizeof(master));
 349                         if (copied) {
 350                                 pr_warn("Partial copy from userspace\n");
 351                                 return -EFAULT;
 352                         }
 353
 354                         /* XXX  We do not want to push aspace, cycle and width
 355                          *      to userspace as they are
 356                          */
 357                         return vme_master_set(image[minor].resource,
 358                                 master.enable, master.vme_addr, master.size,
 359                                 master.aspace, master.cycle, master.dwidth);
 360
 361                         break;
 362                 }
 363                 break;
 364         case SLAVE_MINOR:
 365                 switch (cmd) {
 366                 case VME_GET_SLAVE:
 367                         memset(&slave, 0, sizeof(slave));
 368
 369                         /* XXX  We do not want to push aspace, cycle and width
 370                          *      to userspace as they are
 371                          */
 372                         retval = vme_slave_get(image[minor].resource,
 373                                                &slave.enable, &slave.vme_addr,
 374                                                &slave.size, &pci_addr,
 375                                                &slave.aspace, &slave.cycle);
 376
 377                         copied = copy_to_user(argp, &slave,
 378                                               sizeof(slave));
 379                         if (copied) {
 380                                 pr_warn("Partial copy to userspace\n");
 381                                 return -EFAULT;
 382                         }
 383
 384                         return retval;
 385
 386                 case VME_SET_SLAVE:
 387
 388                         copied = copy_from_user(&slave, argp, sizeof(slave));
 389                         if (copied) {
 390                                 pr_warn("Partial copy from userspace\n");
 391                                 return -EFAULT;
 392                         }
 393
 394                         /* XXX  We do not want to push aspace, cycle and width
 395                          *      to userspace as they are
 396                          */
 397                         return vme_slave_set(image[minor].resource,
 398                                 slave.enable, slave.vme_addr, slave.size,
 399                                 image[minor].pci_buf, slave.aspace,
 400                                 slave.cycle);
 401
 402                         break;
 403                 }
 404                 break;
 405         }
 406
 407         return -EINVAL;
 408 }
 409
 410 static long
 411 vme_user_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 412 {
 413         int ret;
 414         struct inode *inode = file_inode(file);
 415         unsigned int minor = MINOR(inode->i_rdev);
 416
 417         mutex_lock(&image[minor].mutex);
 418         ret = vme_user_ioctl(inode, file, cmd, arg);
 419         mutex_unlock(&image[minor].mutex);
 420
 421         return ret;
 422 }
 423
 424 static void vme_user_vm_open(struct vm_area_struct *vma)
 425 {
 426         struct vme_user_vma_priv *vma_priv = vma->vm_private_data;
 427
 428         refcount_inc(&vma_priv->refcnt);
 429 }
 430
 431 static void vme_user_vm_close(struct vm_area_struct *vma)
 432 {
 433         struct vme_user_vma_priv *vma_priv = vma->vm_private_data;
 434         unsigned int minor = vma_priv->minor;
 435
 436         if (!refcount_dec_and_test(&vma_priv->refcnt))
 437                 return;
 438
 439         mutex_lock(&image[minor].mutex);
 440         image[minor].mmap_count--;
 441         mutex_unlock(&image[minor].mutex);
 442
 443         kfree(vma_priv);
 444 }
 445
 446 static const struct vm_operations_struct vme_user_vm_ops = {
 447         .open = vme_user_vm_open,
 448         .close = vme_user_vm_close,
 449 };
 450
 451 static int vme_user_master_mmap(unsigned int minor, struct vm_area_struct *vma)
 452 {
 453         int err;
 454         struct vme_user_vma_priv *vma_priv;
 455
 456         mutex_lock(&image[minor].mutex);
 457
 458         err = vme_master_mmap(image[minor].resource, vma);
 459         if (err) {
 460                 mutex_unlock(&image[minor].mutex);
 461                 return err;
 462         }
 463
 464         vma_priv = kmalloc(sizeof(*vma_priv), GFP_KERNEL);
 465         if (!vma_priv) {
 466                 mutex_unlock(&image[minor].mutex);
 467                 return -ENOMEM;
 468         }
 469
 470         vma_priv->minor = minor;
 471         refcount_set(&vma_priv->refcnt, 1);
 472         vma->vm_ops = &vme_user_vm_ops;
 473         vma->vm_private_data = vma_priv;
 474
 475         image[minor].mmap_count++;
 476
 477         mutex_unlock(&image[minor].mutex);
 478
 479         return 0;
 480 }
 481
 482 static int vme_user_mmap(struct file *file, struct vm_area_struct *vma)
 483 {
 484         unsigned int minor = MINOR(file_inode(file)->i_rdev);
 485
 486         if (type[minor] == MASTER_MINOR)
 487                 return vme_user_master_mmap(minor, vma);
 488
 489         return -ENODEV;
 490 }
 491
 492 static const struct file_operations vme_user_fops = {
 493         .read = vme_user_read,
 494         .write = vme_user_write,
 495         .llseek = vme_user_llseek,
 496         .unlocked_ioctl = vme_user_unlocked_ioctl,
 497         .compat_ioctl = vme_user_unlocked_ioctl,
 498         .mmap = vme_user_mmap,
 499 };
 500
 501 static int vme_user_match(struct vme_dev *vdev)
 502 {
 503         int i;
 504
 505         int cur_bus = vme_bus_num(vdev);
 506         int cur_slot = vme_slot_num(vdev);
 507
 508         for (i = 0; i < bus_num; i++)
 509                 if ((cur_bus == bus[i]) && (cur_slot == vdev->num))
 510                         return 1;
 511
 512         return 0;
 513 }
 514
 515 /*
 516  * In this simple access driver, the old behaviour is being preserved as much
 517  * as practical. We will therefore reserve the buffers and request the images
 518  * here so that we don't have to do it later.
 519  */
 520 static int vme_user_probe(struct vme_dev *vdev)
 521 {
 522         int i, err;
 523         char *name;
 524
 525         /* Save pointer to the bridge device */
 526         if (vme_user_bridge) {
 527                 dev_err(&vdev->dev, "Driver can only be loaded for 1 device\n");
 528                 err = -EINVAL;
 529                 goto err_dev;
 530         }
 531         vme_user_bridge = vdev;
 532
 533         /* Initialise descriptors */
 534         for (i = 0; i < VME_DEVS; i++) {
 535                 image[i].kern_buf = NULL;
 536                 image[i].pci_buf = 0;
 537                 mutex_init(&image[i].mutex);
 538                 image[i].device = NULL;
 539                 image[i].resource = NULL;
 540         }
 541
 542         /* Assign major and minor numbers for the driver */
 543         err = register_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS,
 544                                      driver_name);
 545         if (err) {
 546                 dev_warn(&vdev->dev, "Error getting Major Number %d for driver.\n",
 547                          VME_MAJOR);
 548                 goto err_region;
 549         }
 550
 551         /* Register the driver as a char device */
 552         vme_user_cdev = cdev_alloc();
 553         if (!vme_user_cdev) {
 554                 err = -ENOMEM;
 555                 goto err_char;
 556         }
 557         vme_user_cdev->ops = &vme_user_fops;
 558         vme_user_cdev->owner = THIS_MODULE;
 559         err = cdev_add(vme_user_cdev, MKDEV(VME_MAJOR, 0), VME_DEVS);
 560         if (err)
 561                 goto err_class;
 562
 563         /* Request slave resources and allocate buffers (128kB wide) */
 564         for (i = SLAVE_MINOR; i < (SLAVE_MAX + 1); i++) {
 565                 /* XXX Need to properly request attributes */
 566                 /* For ca91cx42 bridge there are only two slave windows
 567                  * supporting A16 addressing, so we request A24 supported
 568                  * by all windows.
 569                  */
 570                 image[i].resource = vme_slave_request(vme_user_bridge,
 571                                                       VME_A24, VME_SCT);
 572                 if (!image[i].resource) {
 573                         dev_warn(&vdev->dev,
 574                                  "Unable to allocate slave resource\n");
 575                         err = -ENOMEM;
 576                         goto err_slave;
 577                 }
 578                 image[i].size_buf = PCI_BUF_SIZE;
 579                 image[i].kern_buf = vme_alloc_consistent(image[i].resource,
 580                                                          image[i].size_buf,
 581                                                          &image[i].pci_buf);
 582                 if (!image[i].kern_buf) {
 583                         dev_warn(&vdev->dev,
 584                                  "Unable to allocate memory for buffer\n");
 585                         image[i].pci_buf = 0;
 586                         vme_slave_free(image[i].resource);
 587                         err = -ENOMEM;
 588                         goto err_slave;
 589                 }
 590         }
 591
 592         /*
 593          * Request master resources allocate page sized buffers for small
 594          * reads and writes
 595          */
 596         for (i = MASTER_MINOR; i < (MASTER_MAX + 1); i++) {
 597                 /* XXX Need to properly request attributes */
 598                 image[i].resource = vme_master_request(vme_user_bridge,
 599                                                        VME_A32, VME_SCT,
 600                                                        VME_D32);
 601                 if (!image[i].resource) {
 602                         dev_warn(&vdev->dev,
 603                                  "Unable to allocate master resource\n");
 604                         err = -ENOMEM;
 605                         goto err_master;
 606                 }
 607                 image[i].size_buf = PCI_BUF_SIZE;
 608                 image[i].kern_buf = kmalloc(image[i].size_buf, GFP_KERNEL);
 609                 if (!image[i].kern_buf) {
 610                         err = -ENOMEM;
 611                         vme_master_free(image[i].resource);
 612                         goto err_master;
 613                 }
 614         }
 615
 616         /* Create sysfs entries - on udev systems this creates the dev files */
 617         vme_user_sysfs_class = class_create(THIS_MODULE, driver_name);
 618         if (IS_ERR(vme_user_sysfs_class)) {
 619                 dev_err(&vdev->dev, "Error creating vme_user class.\n");
 620                 err = PTR_ERR(vme_user_sysfs_class);
 621                 goto err_master;
 622         }
 623
 624         /* Add sysfs Entries */
 625         for (i = 0; i < VME_DEVS; i++) {
 626                 int num;
 627
 628                 switch (type[i]) {
 629                 case MASTER_MINOR:
 630                         name = "bus/vme/m%d";
 631                         break;
 632                 case CONTROL_MINOR:
 633                         name = "bus/vme/ctl";
 634                         break;
 635                 case SLAVE_MINOR:
 636                         name = "bus/vme/s%d";
 637                         break;
 638                 default:
 639                         err = -EINVAL;
 640                         goto err_sysfs;
 641                 }
 642
 643                 num = (type[i] == SLAVE_MINOR) ? i - (MASTER_MAX + 1) : i;
 644                 image[i].device = device_create(vme_user_sysfs_class, NULL,
 645                                                 MKDEV(VME_MAJOR, i), NULL,
 646                                                 name, num);
 647                 if (IS_ERR(image[i].device)) {
 648                         dev_info(&vdev->dev, "Error creating sysfs device\n");
 649                         err = PTR_ERR(image[i].device);
 650                         goto err_sysfs;
 651                 }
 652         }
 653
 654         return 0;
 655
 656 err_sysfs:
 657         while (i > 0) {
 658                 i--;
 659                 device_destroy(vme_user_sysfs_class, MKDEV(VME_MAJOR, i));
 660         }
 661         class_destroy(vme_user_sysfs_class);
 662
 663         /* Ensure counter set correctly to unalloc all master windows */
 664         i = MASTER_MAX + 1;
 665 err_master:
 666         while (i > MASTER_MINOR) {
 667                 i--;
 668                 kfree(image[i].kern_buf);
 669                 vme_master_free(image[i].resource);
 670         }
 671
 672         /*
 673          * Ensure counter set correctly to unalloc all slave windows and buffers
 674          */
 675         i = SLAVE_MAX + 1;
 676 err_slave:
 677         while (i > SLAVE_MINOR) {
 678                 i--;
 679                 vme_free_consistent(image[i].resource, image[i].size_buf,
 680                                     image[i].kern_buf, image[i].pci_buf);
 681                 vme_slave_free(image[i].resource);
 682         }
 683 err_class:
 684         cdev_del(vme_user_cdev);
 685 err_char:
 686         unregister_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS);
 687 err_region:
 688 err_dev:
 689         return err;
 690 }
 691
 692 static int vme_user_remove(struct vme_dev *dev)
 693 {
 694         int i;
 695
 696         /* Remove sysfs Entries */
 697         for (i = 0; i < VME_DEVS; i++) {
 698                 mutex_destroy(&image[i].mutex);
 699                 device_destroy(vme_user_sysfs_class, MKDEV(VME_MAJOR, i));
 700         }
 701         class_destroy(vme_user_sysfs_class);
 702
 703         for (i = MASTER_MINOR; i < (MASTER_MAX + 1); i++) {
 704                 kfree(image[i].kern_buf);
 705                 vme_master_free(image[i].resource);
 706         }
 707
 708         for (i = SLAVE_MINOR; i < (SLAVE_MAX + 1); i++) {
 709                 vme_slave_set(image[i].resource, 0, 0, 0, 0, VME_A32, 0);
 710                 vme_free_consistent(image[i].resource, image[i].size_buf,
 711                                     image[i].kern_buf, image[i].pci_buf);
 712                 vme_slave_free(image[i].resource);
 713         }
 714
 715         /* Unregister device driver */
 716         cdev_del(vme_user_cdev);
 717
 718         /* Unregister the major and minor device numbers */
 719         unregister_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS);
 720
 721         return 0;
 722 }
 723
 724 static struct vme_driver vme_user_driver = {
 725         .name = driver_name,
 726         .match = vme_user_match,
 727         .probe = vme_user_probe,
 728         .remove = vme_user_remove,
 729 };
 730
 731 static int __init vme_user_init(void)
 732 {
 733         int retval = 0;
 734
 735         pr_info("VME User Space Access Driver\n");
 736
 737         if (bus_num == 0) {
 738                 pr_err("No cards, skipping registration\n");
 739                 retval = -ENODEV;
 740                 goto err_nocard;
 741         }
 742
 743         /* Let's start by supporting one bus, we can support more than one
 744          * in future revisions if that ever becomes necessary.
 745          */
 746         if (bus_num > VME_USER_BUS_MAX) {
 747                 pr_err("Driver only able to handle %d buses\n",
 748                        VME_USER_BUS_MAX);
 749                 bus_num = VME_USER_BUS_MAX;
 750         }
 751
 752         /*
 753          * Here we just register the maximum number of devices we can and
 754          * leave vme_user_match() to allow only 1 to go through to probe().
 755          * This way, if we later want to allow multiple user access devices,
 756          * we just change the code in vme_user_match().
 757          */
 758         retval = vme_register_driver(&vme_user_driver, VME_MAX_SLOTS);
 759         if (retval)
 760                 goto err_reg;
 761
 762         return retval;
 763
 764 err_reg:
 765 err_nocard:
 766         return retval;
 767 }
 768
 769 static void __exit vme_user_exit(void)
 770 {
 771         vme_unregister_driver(&vme_user_driver);
 772 }
 773
 774 MODULE_PARM_DESC(bus, "Enumeration of VMEbus to which the driver is connected");
 775 module_param_array(bus, int, &bus_num, 0000);
 776
 777 MODULE_DESCRIPTION("VME User Space Access Driver");
 778 MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com");
 779 MODULE_LICENSE("GPL");
 780
 781 module_init(vme_user_init);
 782 module_exit(vme_user_exit);