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 } 287 288 static void mdpy_remove(struct mdev_device *mdev) 289 { 290 struct mdev_state *mdev_state = dev_get_drvdata(&mdev->dev); 291 292 dev_info(&mdev->dev, "%s\n", __func__); 293 294 vfio_unregister_group_dev(&mdev_state->vdev); 295 vfio_put_device(&mdev_state->vdev); 296 } 297 298 static ssize_t mdpy_read(struct vfio_device *vdev, char __user *buf, 299 size_t count, loff_t *ppos) 300 { 301 struct mdev_state *mdev_state = 302 container_of(vdev, struct mdev_state, vdev); 303 unsigned int done = 0; 304 int ret; 305 306 while (count) { 307 size_t filled; 308 309 if (count >= 4 && !(*ppos % 4)) { 310 u32 val; 311 312 ret = mdev_access(mdev_state, (char *)&val, sizeof(val), 313 *ppos, false); 314 if (ret <= 0) 315 goto read_err; 316 317 if (copy_to_user(buf, &val, sizeof(val))) 318 goto read_err; 319 320 filled = 4; 321 } else if (count >= 2 && !(*ppos % 2)) { 322 u16 val; 323 324 ret = mdev_access(mdev_state, (char *)&val, sizeof(val), 325 *ppos, false); 326 if (ret <= 0) 327 goto read_err; 328 329 if (copy_to_user(buf, &val, sizeof(val))) 330 goto read_err; 331 332 filled = 2; 333 } else { 334 u8 val; 335 336 ret = mdev_access(mdev_state, (char *)&val, sizeof(val), 337 *ppos, false); 338 if (ret <= 0) 339 goto read_err; 340 341 if (copy_to_user(buf, &val, sizeof(val))) 342 goto read_err; 343 344 filled = 1; 345 } 346 347 count -= filled; 348 done += filled; 349 *ppos += filled; 350 buf += filled; 351 } 352 353 return done; 354 355 read_err: 356 return -EFAULT; 357 } 358 359 static ssize_t mdpy_write(struct vfio_device *vdev, const char __user *buf, 360 size_t count, loff_t *ppos) 361 { 362 struct mdev_state *mdev_state = 363 container_of(vdev, struct mdev_state, vdev); 364 unsigned int done = 0; 365 int ret; 366 367 while (count) { 368 size_t filled; 369 370 if (count >= 4 && !(*ppos % 4)) { 371 u32 val; 372 373 if (copy_from_user(&val, buf, sizeof(val))) 374 goto write_err; 375 376 ret = mdev_access(mdev_state, (char *)&val, sizeof(val), 377 *ppos, true); 378 if (ret <= 0) 379 goto write_err; 380 381 filled = 4; 382 } else if (count >= 2 && !(*ppos % 2)) { 383 u16 val; 384 385 if (copy_from_user(&val, buf, sizeof(val))) 386 goto write_err; 387 388 ret = mdev_access(mdev_state, (char *)&val, sizeof(val), 389 *ppos, true); 390 if (ret <= 0) 391 goto write_err; 392 393 filled = 2; 394 } else { 395 u8 val; 396 397 if (copy_from_user(&val, buf, sizeof(val))) 398 goto write_err; 399 400 ret = mdev_access(mdev_state, (char *)&val, sizeof(val), 401 *ppos, true); 402 if (ret <= 0) 403 goto write_err; 404 405 filled = 1; 406 } 407 count -= filled; 408 done += filled; 409 *ppos += filled; 410 buf += filled; 411 } 412 413 return done; 414 write_err: 415 return -EFAULT; 416 } 417 418 static int mdpy_mmap(struct vfio_device *vdev, struct vm_area_struct *vma) 419 { 420 struct mdev_state *mdev_state = 421 container_of(vdev, struct mdev_state, vdev); 422 423 if (vma->vm_pgoff != MDPY_MEMORY_BAR_OFFSET >> PAGE_SHIFT) 424 return -EINVAL; 425 if (vma->vm_end < vma->vm_start) 426 return -EINVAL; 427 if (vma->vm_end - vma->vm_start > mdev_state->memsize) 428 return -EINVAL; 429 if ((vma->vm_flags & VM_SHARED) == 0) 430 return -EINVAL; 431 432 return remap_vmalloc_range(vma, mdev_state->memblk, 0); 433 } 434 435 static int mdpy_get_region_info(struct mdev_state *mdev_state, 436 struct vfio_region_info *region_info, 437 u16 *cap_type_id, void **cap_type) 438 { 439 if (region_info->index >= VFIO_PCI_NUM_REGIONS && 440 region_info->index != MDPY_DISPLAY_REGION) 441 return -EINVAL; 442 443 switch (region_info->index) { 444 case VFIO_PCI_CONFIG_REGION_INDEX: 445 region_info->offset = 0; 446 region_info->size = MDPY_CONFIG_SPACE_SIZE; 447 region_info->flags = (VFIO_REGION_INFO_FLAG_READ | 448 VFIO_REGION_INFO_FLAG_WRITE); 449 break; 450 case VFIO_PCI_BAR0_REGION_INDEX: 451 case MDPY_DISPLAY_REGION: 452 region_info->offset = MDPY_MEMORY_BAR_OFFSET; 453 region_info->size = mdev_state->memsize; 454 region_info->flags = (VFIO_REGION_INFO_FLAG_READ | 455 VFIO_REGION_INFO_FLAG_WRITE | 456 VFIO_REGION_INFO_FLAG_MMAP); 457 break; 458 default: 459 region_info->size = 0; 460 region_info->offset = 0; 461 region_info->flags = 0; 462 } 463 464 return 0; 465 } 466 467 static int mdpy_get_irq_info(struct vfio_irq_info *irq_info) 468 { 469 irq_info->count = 0; 470 return 0; 471 } 472 473 static int mdpy_get_device_info(struct vfio_device_info *dev_info) 474 { 475 dev_info->flags = VFIO_DEVICE_FLAGS_PCI; 476 dev_info->num_regions = VFIO_PCI_NUM_REGIONS; 477 dev_info->num_irqs = VFIO_PCI_NUM_IRQS; 478 return 0; 479 } 480 481 static int mdpy_query_gfx_plane(struct mdev_state *mdev_state, 482 struct vfio_device_gfx_plane_info *plane) 483 { 484 if (plane->flags & VFIO_GFX_PLANE_TYPE_PROBE) { 485 if (plane->flags == (VFIO_GFX_PLANE_TYPE_PROBE | 486 VFIO_GFX_PLANE_TYPE_REGION)) 487 return 0; 488 return -EINVAL; 489 } 490 491 if (plane->flags != VFIO_GFX_PLANE_TYPE_REGION) 492 return -EINVAL; 493 494 plane->drm_format = mdev_state->type->format; 495 plane->width = mdev_state->type->width; 496 plane->height = mdev_state->type->height; 497 plane->stride = (mdev_state->type->width * 498 mdev_state->type->bytepp); 499 plane->size = mdev_state->memsize; 500 plane->region_index = MDPY_DISPLAY_REGION; 501 502 /* unused */ 503 plane->drm_format_mod = 0; 504 plane->x_pos = 0; 505 plane->y_pos = 0; 506 plane->x_hot = 0; 507 plane->y_hot = 0; 508 509 return 0; 510 } 511 512 static long mdpy_ioctl(struct vfio_device *vdev, unsigned int cmd, 513 unsigned long arg) 514 { 515 int ret = 0; 516 unsigned long minsz; 517 struct mdev_state *mdev_state = 518 container_of(vdev, struct mdev_state, vdev); 519 520 switch (cmd) { 521 case VFIO_DEVICE_GET_INFO: 522 { 523 struct vfio_device_info info; 524 525 minsz = offsetofend(struct vfio_device_info, num_irqs); 526 527 if (copy_from_user(&info, (void __user *)arg, minsz)) 528 return -EFAULT; 529 530 if (info.argsz < minsz) 531 return -EINVAL; 532 533 ret = mdpy_get_device_info(&info); 534 if (ret) 535 return ret; 536 537 memcpy(&mdev_state->dev_info, &info, sizeof(info)); 538 539 if (copy_to_user((void __user *)arg, &info, minsz)) 540 return -EFAULT; 541 542 return 0; 543 } 544 case VFIO_DEVICE_GET_REGION_INFO: 545 { 546 struct vfio_region_info info; 547 u16 cap_type_id = 0; 548 void *cap_type = NULL; 549 550 minsz = offsetofend(struct vfio_region_info, offset); 551 552 if (copy_from_user(&info, (void __user *)arg, minsz)) 553 return -EFAULT; 554 555 if (info.argsz < minsz) 556 return -EINVAL; 557 558 ret = mdpy_get_region_info(mdev_state, &info, &cap_type_id, 559 &cap_type); 560 if (ret) 561 return ret; 562 563 if (copy_to_user((void __user *)arg, &info, minsz)) 564 return -EFAULT; 565 566 return 0; 567 } 568 569 case VFIO_DEVICE_GET_IRQ_INFO: 570 { 571 struct vfio_irq_info info; 572 573 minsz = offsetofend(struct vfio_irq_info, count); 574 575 if (copy_from_user(&info, (void __user *)arg, minsz)) 576 return -EFAULT; 577 578 if ((info.argsz < minsz) || 579 (info.index >= mdev_state->dev_info.num_irqs)) 580 return -EINVAL; 581 582 ret = mdpy_get_irq_info(&info); 583 if (ret) 584 return ret; 585 586 if (copy_to_user((void __user *)arg, &info, minsz)) 587 return -EFAULT; 588 589 return 0; 590 } 591 592 case VFIO_DEVICE_QUERY_GFX_PLANE: 593 { 594 struct vfio_device_gfx_plane_info plane; 595 596 minsz = offsetofend(struct vfio_device_gfx_plane_info, 597 region_index); 598 599 if (copy_from_user(&plane, (void __user *)arg, minsz)) 600 return -EFAULT; 601 602 if (plane.argsz < minsz) 603 return -EINVAL; 604 605 ret = mdpy_query_gfx_plane(mdev_state, &plane); 606 if (ret) 607 return ret; 608 609 if (copy_to_user((void __user *)arg, &plane, minsz)) 610 return -EFAULT; 611 612 return 0; 613 } 614 615 case VFIO_DEVICE_SET_IRQS: 616 return -EINVAL; 617 618 case VFIO_DEVICE_RESET: 619 return mdpy_reset(mdev_state); 620 } 621 return -ENOTTY; 622 } 623 624 static ssize_t 625 resolution_show(struct device *dev, struct device_attribute *attr, 626 char *buf) 627 { 628 struct mdev_state *mdev_state = dev_get_drvdata(dev); 629 630 return sprintf(buf, "%dx%d\n", 631 mdev_state->type->width, 632 mdev_state->type->height); 633 } 634 static DEVICE_ATTR_RO(resolution); 635 636 static struct attribute *mdev_dev_attrs[] = { 637 &dev_attr_resolution.attr, 638 NULL, 639 }; 640 641 static const struct attribute_group mdev_dev_group = { 642 .name = "vendor", 643 .attrs = mdev_dev_attrs, 644 }; 645 646 static const struct attribute_group *mdev_dev_groups[] = { 647 &mdev_dev_group, 648 NULL, 649 }; 650 651 static ssize_t mdpy_show_description(struct mdev_type *mtype, char *buf) 652 { 653 struct mdpy_type *type = container_of(mtype, struct mdpy_type, type); 654 655 return sprintf(buf, "virtual display, %dx%d framebuffer\n", 656 type->width, type->height); 657 } 658 659 static const struct vfio_device_ops mdpy_dev_ops = { 660 .init = mdpy_init_dev, 661 .release = mdpy_release_dev, 662 .read = mdpy_read, 663 .write = mdpy_write, 664 .ioctl = mdpy_ioctl, 665 .mmap = mdpy_mmap, 666 .bind_iommufd = vfio_iommufd_emulated_bind, 667 .unbind_iommufd = vfio_iommufd_emulated_unbind, 668 .attach_ioas = vfio_iommufd_emulated_attach_ioas, 669 .detach_ioas = vfio_iommufd_emulated_detach_ioas, 670 }; 671 672 static struct mdev_driver mdpy_driver = { 673 .device_api = VFIO_DEVICE_API_PCI_STRING, 674 .max_instances = 4, 675 .driver = { 676 .name = "mdpy", 677 .owner = THIS_MODULE, 678 .mod_name = KBUILD_MODNAME, 679 .dev_groups = mdev_dev_groups, 680 }, 681 .probe = mdpy_probe, 682 .remove = mdpy_remove, 683 .show_description = mdpy_show_description, 684 }; 685 686 static const struct file_operations vd_fops = { 687 .owner = THIS_MODULE, 688 }; 689 690 static void mdpy_device_release(struct device *dev) 691 { 692 /* nothing */ 693 } 694 695 static int __init mdpy_dev_init(void) 696 { 697 int ret = 0; 698 699 ret = alloc_chrdev_region(&mdpy_devt, 0, MINORMASK + 1, MDPY_NAME); 700 if (ret < 0) { 701 pr_err("Error: failed to register mdpy_dev, err: %d\n", ret); 702 return ret; 703 } 704 cdev_init(&mdpy_cdev, &vd_fops); 705 cdev_add(&mdpy_cdev, mdpy_devt, MINORMASK + 1); 706 pr_info("%s: major %d\n", __func__, MAJOR(mdpy_devt)); 707 708 ret = mdev_register_driver(&mdpy_driver); 709 if (ret) 710 goto err_cdev; 711 712 mdpy_class = class_create(MDPY_CLASS_NAME); 713 if (IS_ERR(mdpy_class)) { 714 pr_err("Error: failed to register mdpy_dev class\n"); 715 ret = PTR_ERR(mdpy_class); 716 goto err_driver; 717 } 718 mdpy_dev.class = mdpy_class; 719 mdpy_dev.release = mdpy_device_release; 720 dev_set_name(&mdpy_dev, "%s", MDPY_NAME); 721 722 ret = device_register(&mdpy_dev); 723 if (ret) 724 goto err_put; 725 726 ret = mdev_register_parent(&mdpy_parent, &mdpy_dev, &mdpy_driver, 727 mdpy_mdev_types, 728 ARRAY_SIZE(mdpy_mdev_types)); 729 if (ret) 730 goto err_device; 731 732 return 0; 733 734 err_device: 735 device_del(&mdpy_dev); 736 err_put: 737 put_device(&mdpy_dev); 738 class_destroy(mdpy_class); 739 err_driver: 740 mdev_unregister_driver(&mdpy_driver); 741 err_cdev: 742 cdev_del(&mdpy_cdev); 743 unregister_chrdev_region(mdpy_devt, MINORMASK + 1); 744 return ret; 745 } 746 747 static void __exit mdpy_dev_exit(void) 748 { 749 mdpy_dev.bus = NULL; 750 mdev_unregister_parent(&mdpy_parent); 751 752 device_unregister(&mdpy_dev); 753 mdev_unregister_driver(&mdpy_driver); 754 cdev_del(&mdpy_cdev); 755 unregister_chrdev_region(mdpy_devt, MINORMASK + 1); 756 class_destroy(mdpy_class); 757 mdpy_class = NULL; 758 } 759 760 module_param_named(count, mdpy_driver.max_instances, int, 0444); 761 MODULE_PARM_DESC(count, "number of " MDPY_NAME " devices"); 762 763 module_init(mdpy_dev_init) 764 module_exit(mdpy_dev_exit) 765