linux/drivers/staging/vme/devices/vme_user.c
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   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
  40static const char driver_name[] = "vme_user";
  41
  42static int bus[VME_USER_BUS_MAX];
  43static 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 */
  91struct 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
 101static struct image_desc image[VME_DEVS];
 102
 103static struct cdev *vme_user_cdev;              /* Character device */
 104static struct class *vme_user_sysfs_class;      /* Sysfs class */
 105static struct vme_dev *vme_user_bridge;         /* Pointer to user device */
 106
 107static 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
 114struct vme_user_vma_priv {
 115        unsigned int minor;
 116        refcount_t refcnt;
 117};
 118
 119static 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
 138static 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
 151static 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
 163static 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
 175static 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
 218static 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
 261static 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 */
 290static 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
 410static long
 411vme_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
 424static 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
 431static 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
 446static const struct vm_operations_struct vme_user_vm_ops = {
 447        .open = vme_user_vm_open,
 448        .close = vme_user_vm_close,
 449};
 450
 451static 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
 482static 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
 492static 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
 501static 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 */
 520static 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
 656err_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;
 665err_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;
 676err_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        }
 683err_class:
 684        cdev_del(vme_user_cdev);
 685err_char:
 686        unregister_chrdev_region(MKDEV(VME_MAJOR, 0), VME_DEVS);
 687err_region:
 688err_dev:
 689        return err;
 690}
 691
 692static 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
 724static 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
 731static 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
 764err_reg:
 765err_nocard:
 766        return retval;
 767}
 768
 769static void __exit vme_user_exit(void)
 770{
 771        vme_unregister_driver(&vme_user_driver);
 772}
 773
 774MODULE_PARM_DESC(bus, "Enumeration of VMEbus to which the driver is connected");
 775module_param_array(bus, int, &bus_num, 0000);
 776
 777MODULE_DESCRIPTION("VME User Space Access Driver");
 778MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com");
 779MODULE_LICENSE("GPL");
 780
 781module_init(vme_user_init);
 782module_exit(vme_user_exit);
 783