1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Mediated virtual PCI display host device driver 4 * 5 * See mdpy-defs.h for device specs 6 * 7 * (c) Gerd Hoffmann <kraxel@redhat.com> 8 * 9 * based on mtty driver which is: 10 * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved. 11 * Author: Neo Jia <cjia@nvidia.com> 12 * Kirti Wankhede <kwankhede@nvidia.com> 13 * 14 * This program is free software; you can redistribute it and/or modify 15 * it under the terms of the GNU General Public License version 2 as 16 * published by the Free Software Foundation. 17 */ 18 #include <linux/init.h> 19 #include <linux/module.h> 20 #include <linux/kernel.h> 21 #include <linux/slab.h> 22 #include <linux/vmalloc.h> 23 #include <linux/cdev.h> 24 #include <linux/vfio.h> 25 #include <linux/iommu.h> 26 #include <linux/sysfs.h> 27 #include <linux/mdev.h> 28 #include <linux/pci.h> 29 #include <drm/drm_fourcc.h> 30 #include "mdpy-defs.h" 31 32 #define MDPY_NAME "mdpy" 33 #define MDPY_CLASS_NAME "mdpy" 34 35 #define MDPY_CONFIG_SPACE_SIZE 0xff 36 #define MDPY_MEMORY_BAR_OFFSET PAGE_SIZE 37 #define MDPY_DISPLAY_REGION 16 38 39 #define STORE_LE16(addr, val) (*(u16 *)addr = val) 40 #define STORE_LE32(addr, val) (*(u32 *)addr = val) 41 42 43 MODULE_LICENSE("GPL v2"); 44 45 #define MDPY_TYPE_1 "vga" 46 #define MDPY_TYPE_2 "xga" 47 #define MDPY_TYPE_3 "hd" 48 49 static struct mdpy_type { 50 struct mdev_type type; 51 u32 format; 52 u32 bytepp; 53 u32 width; 54 u32 height; 55 } mdpy_types[] = { 56 { 57 .type.sysfs_name = MDPY_TYPE_1, 58 .type.pretty_name = MDPY_CLASS_NAME "-" MDPY_TYPE_1, 59 .format = DRM_FORMAT_XRGB8888, 60 .bytepp = 4, 61 .width = 640, 62 .height = 480, 63 }, { 64 .type.sysfs_name = MDPY_TYPE_2, 65 .type.pretty_name = MDPY_CLASS_NAME "-" MDPY_TYPE_2, 66 .format = DRM_FORMAT_XRGB8888, 67 .bytepp = 4, 68 .width = 1024, 69 .height = 768, 70 }, { 71 .type.sysfs_name = MDPY_TYPE_3, 72 .type.pretty_name = MDPY_CLASS_NAME "-" MDPY_TYPE_3, 73 .format = DRM_FORMAT_XRGB8888, 74 .bytepp = 4, 75 .width = 1920, 76 .height = 1080, 77 }, 78 }; 79 80 static struct mdev_type *mdpy_mdev_types[] = { 81 &mdpy_types[0].type, 82 &mdpy_types[1].type, 83 &mdpy_types[2].type, 84 }; 85 86 static dev_t mdpy_devt; 87 static struct class *mdpy_class; 88 static struct cdev mdpy_cdev; 89 static struct device mdpy_dev; 90 static struct mdev_parent mdpy_parent; 91 static const struct vfio_device_ops mdpy_dev_ops; 92 93 /* State of each mdev device */ 94 struct mdev_state { 95 struct vfio_device vdev; 96 u8 *vconfig; 97 u32 bar_mask; 98 struct mutex ops_lock; 99 struct mdev_device *mdev; 100 struct vfio_device_info dev_info; 101 102 const struct mdpy_type *type; 103 u32 memsize; 104 void *memblk; 105 }; 106 107 static void mdpy_create_config_space(struct mdev_state *mdev_state) 108 { 109 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_VENDOR_ID], 110 MDPY_PCI_VENDOR_ID); 111 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_DEVICE_ID], 112 MDPY_PCI_DEVICE_ID); 113 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_VENDOR_ID], 114 MDPY_PCI_SUBVENDOR_ID); 115 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_SUBSYSTEM_ID], 116 MDPY_PCI_SUBDEVICE_ID); 117 118 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_COMMAND], 119 PCI_COMMAND_IO | PCI_COMMAND_MEMORY); 120 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_STATUS], 121 PCI_STATUS_CAP_LIST); 122 STORE_LE16((u16 *) &mdev_state->vconfig[PCI_CLASS_DEVICE], 123 PCI_CLASS_DISPLAY_OTHER); 124 mdev_state->vconfig[PCI_CLASS_REVISION] = 0x01; 125 126 STORE_LE32((u32 *) &mdev_state->vconfig[PCI_BASE_ADDRESS_0], 127 PCI_BASE_ADDRESS_SPACE_MEMORY | 128 PCI_BASE_ADDRESS_MEM_TYPE_32 | 129 PCI_BASE_ADDRESS_MEM_PREFETCH); 130 mdev_state->bar_mask = ~(mdev_state->memsize) + 1; 131 132 /* vendor specific capability for the config registers */ 133 mdev_state->vconfig[PCI_CAPABILITY_LIST] = MDPY_VENDORCAP_OFFSET; 134 mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 0] = 0x09; /* vendor cap */ 135 mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 1] = 0x00; /* next ptr */ 136 mdev_state->vconfig[MDPY_VENDORCAP_OFFSET + 2] = MDPY_VENDORCAP_SIZE; 137 STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_FORMAT_OFFSET], 138 mdev_state->type->format); 139 STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_WIDTH_OFFSET], 140 mdev_state->type->width); 141 STORE_LE32((u32 *) &mdev_state->vconfig[MDPY_HEIGHT_OFFSET], 142 mdev_state->type->height); 143 } 144 145 static void handle_pci_cfg_write(struct mdev_state *mdev_state, u16 offset, 146 char *buf, u32 count) 147 { 148 struct device *dev = mdev_dev(mdev_state->mdev); 149 u32 cfg_addr; 150 151 switch (offset) { 152 case PCI_BASE_ADDRESS_0: 153 cfg_addr = *(u32 *)buf; 154 155 if (cfg_addr == 0xffffffff) { 156 cfg_addr = (cfg_addr & mdev_state->bar_mask); 157 } else { 158 cfg_addr &= PCI_BASE_ADDRESS_MEM_MASK; 159 if (cfg_addr) 160 dev_info(dev, "BAR0 @ 0x%x\n", cfg_addr); 161 } 162 163 cfg_addr |= (mdev_state->vconfig[offset] & 164 ~PCI_BASE_ADDRESS_MEM_MASK); 165 STORE_LE32(&mdev_state->vconfig[offset], cfg_addr); 166 break; 167 } 168 } 169 170 static ssize_t mdev_access(struct mdev_state *mdev_state, char *buf, 171 size_t count, loff_t pos, bool is_write) 172 { 173 int ret = 0; 174 175 mutex_lock(&mdev_state->ops_lock); 176 177 if (pos < MDPY_CONFIG_SPACE_SIZE) { 178 if (is_write) 179 handle_pci_cfg_write(mdev_state, pos, buf, count); 180 else 181 memcpy(buf, (mdev_state->vconfig + pos), count); 182 183 } else if ((pos >= MDPY_MEMORY_BAR_OFFSET) && 184 (pos + count <= 185 MDPY_MEMORY_BAR_OFFSET + mdev_state->memsize)) { 186 pos -= MDPY_MEMORY_BAR_OFFSET; 187 if (is_write) 188 memcpy(mdev_state->memblk, buf, count); 189 else 190 memcpy(buf, mdev_state->memblk, count); 191 192 } else { 193 dev_info(mdev_state->vdev.dev, 194 "%s: %s @0x%llx (unhandled)\n", __func__, 195 is_write ? "WR" : "RD", pos); 196 ret = -1; 197 goto accessfailed; 198 } 199 200 ret = count; 201 202 203 accessfailed: 204 mutex_unlock(&mdev_state->ops_lock); 205 206 return ret; 207 } 208 209 static int mdpy_reset(struct mdev_state *mdev_state) 210 { 211 u32 stride, i; 212 213 /* initialize with gray gradient */ 214 stride = mdev_state->type->width * mdev_state->type->bytepp; 215 for (i = 0; i < mdev_state->type->height; i++) 216 memset(mdev_state->memblk + i * stride, 217 i * 255 / mdev_state->type->height, 218 stride); 219 return 0; 220 } 221 222 static int mdpy_init_dev(struct vfio_device *vdev) 223 { 224 struct mdev_state *mdev_state = 225 container_of(vdev, struct mdev_state, vdev); 226 struct mdev_device *mdev = to_mdev_device(vdev->dev); 227 const struct mdpy_type *type = 228 container_of(mdev->type, struct mdpy_type, type); 229 u32 fbsize; 230 int ret = -ENOMEM; 231 232 mdev_state->vconfig = kzalloc(MDPY_CONFIG_SPACE_SIZE, GFP_KERNEL); 233 if (!mdev_state->vconfig) 234 return ret; 235 236 fbsize = roundup_pow_of_two(type->width * type->height * type->bytepp); 237 238 mdev_state->memblk = vmalloc_user(fbsize); 239 if (!mdev_state->memblk) 240 goto out_vconfig; 241 242 mutex_init(&mdev_state->ops_lock); 243 mdev_state->mdev = mdev; 244 mdev_state->type = type; 245 mdev_state->memsize = fbsize; 246 mdpy_create_config_space(mdev_state); 247 mdpy_reset(mdev_state); 248 249 dev_info(vdev->dev, "%s: %s (%dx%d)\n", __func__, type->type.pretty_name, 250 type->width, type->height); 251 return 0; 252 253 out_vconfig: 254 kfree(mdev_state->vconfig); 255 return ret; 256 } 257 258 static int mdpy_probe(struct mdev_device *mdev) 259 { 260 struct mdev_state *mdev_state; 261 int ret; 262 263 mdev_state = vfio_alloc_device(mdev_state, vdev, &mdev->dev, 264 &mdpy_dev_ops); 265 if (IS_ERR(mdev_state)) 266 return PTR_ERR(mdev_state); 267 268 ret = vfio_register_emulated_iommu_dev(&mdev_state->vdev); 269 if (ret) 270 goto err_put_vdev; 271 dev_set_drvdata(&mdev->dev, mdev_state); 272 return 0; 273 274 err_put_vdev: 275 vfio_put_device(&mdev_state->vdev); 276 return ret; 277 } 278 279 static void mdpy_release_dev(struct vfio_device *vdev) 280 { 281 struct mdev_state *mdev_state = 282 container_of(vdev, struct mdev_state, vdev); 283 284 vfree(mdev_state->memblk); 285 kfree(mdev_state->vconfig); 286 vfio_free_device(vdev); 287 } 288 289 static void mdpy_remove(struct mdev_device *mdev) 290 { 291 struct mdev_state *mdev_state = dev_get_drvdata(&mdev->dev); 292 293 dev_info(&mdev->dev, "%s\n", __func__); 294 295 vfio_unregister_group_dev(&mdev_state->vdev); 296 vfio_put_device(&mdev_state->vdev); 297 } 298 299 static ssize_t mdpy_read(struct vfio_device *vdev, char __user *buf, 300 size_t count, loff_t *ppos) 301 { 302 struct mdev_state *mdev_state = 303 container_of(vdev, struct mdev_state, vdev); 304 unsigned int done = 0; 305 int ret; 306 307 while (count) { 308 size_t filled; 309 310 if (count >= 4 && !(*ppos % 4)) { 311 u32 val; 312 313 ret = mdev_access(mdev_state, (char *)&val, sizeof(val), 314 *ppos, false); 315 if (ret <= 0) 316 goto read_err; 317 318 if (copy_to_user(buf, &val, sizeof(val))) 319 goto read_err; 320 321 filled = 4; 322 } else if (count >= 2 && !(*ppos % 2)) { 323 u16 val; 324 325 ret = mdev_access(mdev_state, (char *)&val, sizeof(val), 326 *ppos, false); 327 if (ret <= 0) 328 goto read_err; 329 330 if (copy_to_user(buf, &val, sizeof(val))) 331 goto read_err; 332 333 filled = 2; 334 } else { 335 u8 val; 336 337 ret = mdev_access(mdev_state, (char *)&val, sizeof(val), 338 *ppos, false); 339 if (ret <= 0) 340 goto read_err; 341 342 if (copy_to_user(buf, &val, sizeof(val))) 343 goto read_err; 344 345 filled = 1; 346 } 347 348 count -= filled; 349 done += filled; 350 *ppos += filled; 351 buf += filled; 352 } 353 354 return done; 355 356 read_err: 357 return -EFAULT; 358 } 359 360 static ssize_t mdpy_write(struct vfio_device *vdev, const char __user *buf, 361 size_t count, loff_t *ppos) 362 { 363 struct mdev_state *mdev_state = 364 container_of(vdev, struct mdev_state, vdev); 365 unsigned int done = 0; 366 int ret; 367 368 while (count) { 369 size_t filled; 370 371 if (count >= 4 && !(*ppos % 4)) { 372 u32 val; 373 374 if (copy_from_user(&val, buf, sizeof(val))) 375 goto write_err; 376 377 ret = mdev_access(mdev_state, (char *)&val, sizeof(val), 378 *ppos, true); 379 if (ret <= 0) 380 goto write_err; 381 382 filled = 4; 383 } else if (count >= 2 && !(*ppos % 2)) { 384 u16 val; 385 386 if (copy_from_user(&val, buf, sizeof(val))) 387 goto write_err; 388 389 ret = mdev_access(mdev_state, (char *)&val, sizeof(val), 390 *ppos, true); 391 if (ret <= 0) 392 goto write_err; 393 394 filled = 2; 395 } else { 396 u8 val; 397 398 if (copy_from_user(&val, buf, sizeof(val))) 399 goto write_err; 400 401 ret = mdev_access(mdev_state, (char *)&val, sizeof(val), 402 *ppos, true); 403 if (ret <= 0) 404 goto write_err; 405 406 filled = 1; 407 } 408 count -= filled; 409 done += filled; 410 *ppos += filled; 411 buf += filled; 412 } 413 414 return done; 415 write_err: 416 return -EFAULT; 417 } 418 419 static int mdpy_mmap(struct vfio_device *vdev, struct vm_area_struct *vma) 420 { 421 struct mdev_state *mdev_state = 422 container_of(vdev, struct mdev_state, vdev); 423 424 if (vma->vm_pgoff != MDPY_MEMORY_BAR_OFFSET >> PAGE_SHIFT) 425 return -EINVAL; 426 if (vma->vm_end < vma->vm_start) 427 return -EINVAL; 428 if (vma->vm_end - vma->vm_start > mdev_state->memsize) 429 return -EINVAL; 430 if ((vma->vm_flags & VM_SHARED) == 0) 431 return -EINVAL; 432 433 return remap_vmalloc_range(vma, mdev_state->memblk, 0); 434 } 435 436 static int mdpy_get_region_info(struct mdev_state *mdev_state, 437 struct vfio_region_info *region_info, 438 u16 *cap_type_id, void **cap_type) 439 { 440 if (region_info->index >= VFIO_PCI_NUM_REGIONS && 441 region_info->index != MDPY_DISPLAY_REGION) 442 return -EINVAL; 443 444 switch (region_info->index) { 445 case VFIO_PCI_CONFIG_REGION_INDEX: 446 region_info->offset = 0; 447 region_info->size = MDPY_CONFIG_SPACE_SIZE; 448 region_info->flags = (VFIO_REGION_INFO_FLAG_READ | 449 VFIO_REGION_INFO_FLAG_WRITE); 450 break; 451 case VFIO_PCI_BAR0_REGION_INDEX: 452 case MDPY_DISPLAY_REGION: 453 region_info->offset = MDPY_MEMORY_BAR_OFFSET; 454 region_info->size = mdev_state->memsize; 455 region_info->flags = (VFIO_REGION_INFO_FLAG_READ | 456 VFIO_REGION_INFO_FLAG_WRITE | 457 VFIO_REGION_INFO_FLAG_MMAP); 458 break; 459 default: 460 region_info->size = 0; 461 region_info->offset = 0; 462 region_info->flags = 0; 463 } 464 465 return 0; 466 } 467 468 static int mdpy_get_irq_info(struct vfio_irq_info *irq_info) 469 { 470 irq_info->count = 0; 471 return 0; 472 } 473 474 static int mdpy_get_device_info(struct vfio_device_info *dev_info) 475 { 476 dev_info->flags = VFIO_DEVICE_FLAGS_PCI; 477 dev_info->num_regions = VFIO_PCI_NUM_REGIONS; 478 dev_info->num_irqs = VFIO_PCI_NUM_IRQS; 479 return 0; 480 } 481 482 static int mdpy_query_gfx_plane(struct mdev_state *mdev_state, 483 struct vfio_device_gfx_plane_info *plane) 484 { 485 if (plane->flags & VFIO_GFX_PLANE_TYPE_PROBE) { 486 if (plane->flags == (VFIO_GFX_PLANE_TYPE_PROBE | 487 VFIO_GFX_PLANE_TYPE_REGION)) 488 return 0; 489 return -EINVAL; 490 } 491 492 if (plane->flags != VFIO_GFX_PLANE_TYPE_REGION) 493 return -EINVAL; 494 495 plane->drm_format = mdev_state->type->format; 496 plane->width = mdev_state->type->width; 497 plane->height = mdev_state->type->height; 498 plane->stride = (mdev_state->type->width * 499 mdev_state->type->bytepp); 500 plane->size = mdev_state->memsize; 501 plane->region_index = MDPY_DISPLAY_REGION; 502 503 /* unused */ 504 plane->drm_format_mod = 0; 505 plane->x_pos = 0; 506 plane->y_pos = 0; 507 plane->x_hot = 0; 508 plane->y_hot = 0; 509 510 return 0; 511 } 512 513 static long mdpy_ioctl(struct vfio_device *vdev, unsigned int cmd, 514 unsigned long arg) 515 { 516 int ret = 0; 517 unsigned long minsz; 518 struct mdev_state *mdev_state = 519 container_of(vdev, struct mdev_state, vdev); 520 521 switch (cmd) { 522 case VFIO_DEVICE_GET_INFO: 523 { 524 struct vfio_device_info info; 525 526 minsz = offsetofend(struct vfio_device_info, num_irqs); 527 528 if (copy_from_user(&info, (void __user *)arg, minsz)) 529 return -EFAULT; 530 531 if (info.argsz < minsz) 532 return -EINVAL; 533 534 ret = mdpy_get_device_info(&info); 535 if (ret) 536 return ret; 537 538 memcpy(&mdev_state->dev_info, &info, sizeof(info)); 539 540 if (copy_to_user((void __user *)arg, &info, minsz)) 541 return -EFAULT; 542 543 return 0; 544 } 545 case VFIO_DEVICE_GET_REGION_INFO: 546 { 547 struct vfio_region_info info; 548 u16 cap_type_id = 0; 549 void *cap_type = NULL; 550 551 minsz = offsetofend(struct vfio_region_info, offset); 552 553 if (copy_from_user(&info, (void __user *)arg, minsz)) 554 return -EFAULT; 555 556 if (info.argsz < minsz) 557 return -EINVAL; 558 559 ret = mdpy_get_region_info(mdev_state, &info, &cap_type_id, 560 &cap_type); 561 if (ret) 562 return ret; 563 564 if (copy_to_user((void __user *)arg, &info, minsz)) 565 return -EFAULT; 566 567 return 0; 568 } 569 570 case VFIO_DEVICE_GET_IRQ_INFO: 571 { 572 struct vfio_irq_info info; 573 574 minsz = offsetofend(struct vfio_irq_info, count); 575 576 if (copy_from_user(&info, (void __user *)arg, minsz)) 577 return -EFAULT; 578 579 if ((info.argsz < minsz) || 580 (info.index >= mdev_state->dev_info.num_irqs)) 581 return -EINVAL; 582 583 ret = mdpy_get_irq_info(&info); 584 if (ret) 585 return ret; 586 587 if (copy_to_user((void __user *)arg, &info, minsz)) 588 return -EFAULT; 589 590 return 0; 591 } 592 593 case VFIO_DEVICE_QUERY_GFX_PLANE: 594 { 595 struct vfio_device_gfx_plane_info plane; 596 597 minsz = offsetofend(struct vfio_device_gfx_plane_info, 598 region_index); 599 600 if (copy_from_user(&plane, (void __user *)arg, minsz)) 601 return -EFAULT; 602 603 if (plane.argsz < minsz) 604 return -EINVAL; 605 606 ret = mdpy_query_gfx_plane(mdev_state, &plane); 607 if (ret) 608 return ret; 609 610 if (copy_to_user((void __user *)arg, &plane, minsz)) 611 return -EFAULT; 612 613 return 0; 614 } 615 616 case VFIO_DEVICE_SET_IRQS: 617 return -EINVAL; 618 619 case VFIO_DEVICE_RESET: 620 return mdpy_reset(mdev_state); 621 } 622 return -ENOTTY; 623 } 624 625 static ssize_t 626 resolution_show(struct device *dev, struct device_attribute *attr, 627 char *buf) 628 { 629 struct mdev_state *mdev_state = dev_get_drvdata(dev); 630 631 return sprintf(buf, "%dx%d\n", 632 mdev_state->type->width, 633 mdev_state->type->height); 634 } 635 static DEVICE_ATTR_RO(resolution); 636 637 static struct attribute *mdev_dev_attrs[] = { 638 &dev_attr_resolution.attr, 639 NULL, 640 }; 641 642 static const struct attribute_group mdev_dev_group = { 643 .name = "vendor", 644 .attrs = mdev_dev_attrs, 645 }; 646 647 static const struct attribute_group *mdev_dev_groups[] = { 648 &mdev_dev_group, 649 NULL, 650 }; 651 652 static ssize_t mdpy_show_description(struct mdev_type *mtype, char *buf) 653 { 654 struct mdpy_type *type = container_of(mtype, struct mdpy_type, type); 655 656 return sprintf(buf, "virtual display, %dx%d framebuffer\n", 657 type->width, type->height); 658 } 659 660 static const struct vfio_device_ops mdpy_dev_ops = { 661 .init = mdpy_init_dev, 662 .release = mdpy_release_dev, 663 .read = mdpy_read, 664 .write = mdpy_write, 665 .ioctl = mdpy_ioctl, 666 .mmap = mdpy_mmap, 667 }; 668 669 static struct mdev_driver mdpy_driver = { 670 .device_api = VFIO_DEVICE_API_PCI_STRING, 671 .max_instances = 4, 672 .driver = { 673 .name = "mdpy", 674 .owner = THIS_MODULE, 675 .mod_name = KBUILD_MODNAME, 676 .dev_groups = mdev_dev_groups, 677 }, 678 .probe = mdpy_probe, 679 .remove = mdpy_remove, 680 .show_description = mdpy_show_description, 681 }; 682 683 static const struct file_operations vd_fops = { 684 .owner = THIS_MODULE, 685 }; 686 687 static void mdpy_device_release(struct device *dev) 688 { 689 /* nothing */ 690 } 691 692 static int __init mdpy_dev_init(void) 693 { 694 int ret = 0; 695 696 ret = alloc_chrdev_region(&mdpy_devt, 0, MINORMASK + 1, MDPY_NAME); 697 if (ret < 0) { 698 pr_err("Error: failed to register mdpy_dev, err: %d\n", ret); 699 return ret; 700 } 701 cdev_init(&mdpy_cdev, &vd_fops); 702 cdev_add(&mdpy_cdev, mdpy_devt, MINORMASK + 1); 703 pr_info("%s: major %d\n", __func__, MAJOR(mdpy_devt)); 704 705 ret = mdev_register_driver(&mdpy_driver); 706 if (ret) 707 goto err_cdev; 708 709 mdpy_class = class_create(THIS_MODULE, MDPY_CLASS_NAME); 710 if (IS_ERR(mdpy_class)) { 711 pr_err("Error: failed to register mdpy_dev class\n"); 712 ret = PTR_ERR(mdpy_class); 713 goto err_driver; 714 } 715 mdpy_dev.class = mdpy_class; 716 mdpy_dev.release = mdpy_device_release; 717 dev_set_name(&mdpy_dev, "%s", MDPY_NAME); 718 719 ret = device_register(&mdpy_dev); 720 if (ret) 721 goto err_class; 722 723 ret = mdev_register_parent(&mdpy_parent, &mdpy_dev, &mdpy_driver, 724 mdpy_mdev_types, 725 ARRAY_SIZE(mdpy_mdev_types)); 726 if (ret) 727 goto err_device; 728 729 return 0; 730 731 err_device: 732 device_unregister(&mdpy_dev); 733 err_class: 734 class_destroy(mdpy_class); 735 err_driver: 736 mdev_unregister_driver(&mdpy_driver); 737 err_cdev: 738 cdev_del(&mdpy_cdev); 739 unregister_chrdev_region(mdpy_devt, MINORMASK + 1); 740 return ret; 741 } 742 743 static void __exit mdpy_dev_exit(void) 744 { 745 mdpy_dev.bus = NULL; 746 mdev_unregister_parent(&mdpy_parent); 747 748 device_unregister(&mdpy_dev); 749 mdev_unregister_driver(&mdpy_driver); 750 cdev_del(&mdpy_cdev); 751 unregister_chrdev_region(mdpy_devt, MINORMASK + 1); 752 class_destroy(mdpy_class); 753 mdpy_class = NULL; 754 } 755 756 module_param_named(count, mdpy_driver.max_instances, int, 0444); 757 MODULE_PARM_DESC(count, "number of " MDPY_NAME " devices"); 758 759 module_init(mdpy_dev_init) 760 module_exit(mdpy_dev_exit) 761