release/src-rt-6.x.4708/linux/linux-2.6.36/drivers/video/via/via-core.c

   1 /*
   2  * Copyright 1998-2009 VIA Technologies, Inc. All Rights Reserved.
   3  * Copyright 2001-2008 S3 Graphics, Inc. All Rights Reserved.
   4  * Copyright 2009 Jonathan Corbet <corbet@lwn.net>
   5  */
   6
   7 /*
   8  * Core code for the Via multifunction framebuffer device.
   9  */
  10 #include <linux/via-core.h>
  11 #include <linux/via_i2c.h>
  12 #include <linux/via-gpio.h>
  13 #include "global.h"
  14
  15 #include <linux/module.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/platform_device.h>
  18
  19 /*
  20  * The default port config.
  21  */
  22 static struct via_port_cfg adap_configs[] = {
  23         [VIA_PORT_26]   = { VIA_PORT_I2C,  VIA_MODE_OFF, VIASR, 0x26 },
  24         [VIA_PORT_31]   = { VIA_PORT_I2C,  VIA_MODE_I2C, VIASR, 0x31 },
  25         [VIA_PORT_25]   = { VIA_PORT_GPIO, VIA_MODE_GPIO, VIASR, 0x25 },
  26         [VIA_PORT_2C]   = { VIA_PORT_GPIO, VIA_MODE_I2C, VIASR, 0x2c },
  27         [VIA_PORT_3D]   = { VIA_PORT_GPIO, VIA_MODE_GPIO, VIASR, 0x3d },
  28         { 0, 0, 0, 0 }
  29 };
  30
  31 /*
  32  * We currently only support one viafb device (will there ever be
  33  * more than one?), so just declare it globally here.
  34  */
  35 static struct viafb_dev global_dev;
  36
  37
  38 /*
  39  * Basic register access; spinlock required.
  40  */
  41 static inline void viafb_mmio_write(int reg, u32 v)
  42 {
  43         iowrite32(v, global_dev.engine_mmio + reg);
  44 }
  45
  46 static inline int viafb_mmio_read(int reg)
  47 {
  48         return ioread32(global_dev.engine_mmio + reg);
  49 }
  50
  51 /* ---------------------------------------------------------------------- */
  52 /*
  53  * Interrupt management.  We have a single IRQ line for a lot of
  54  * different functions, so we need to share it.  The design here
  55  * is that we don't want to reimplement the shared IRQ code here;
  56  * we also want to avoid having contention for a single handler thread.
  57  * So each subdev driver which needs interrupts just requests
  58  * them directly from the kernel.  We just have what's needed for
  59  * overall access to the interrupt control register.
  60  */
  61
  62 /*
  63  * Which interrupts are enabled now?
  64  */
  65 static u32 viafb_enabled_ints;
  66
  67 static void __devinit viafb_int_init(void)
  68 {
  69         viafb_enabled_ints = 0;
  70
  71         viafb_mmio_write(VDE_INTERRUPT, 0);
  72 }
  73
  74 /*
  75  * Allow subdevs to ask for specific interrupts to be enabled.  These
  76  * functions must be called with reg_lock held
  77  */
  78 void viafb_irq_enable(u32 mask)
  79 {
  80         viafb_enabled_ints |= mask;
  81         viafb_mmio_write(VDE_INTERRUPT, viafb_enabled_ints | VDE_I_ENABLE);
  82 }
  83 EXPORT_SYMBOL_GPL(viafb_irq_enable);
  84
  85 void viafb_irq_disable(u32 mask)
  86 {
  87         viafb_enabled_ints &= ~mask;
  88         if (viafb_enabled_ints == 0)
  89                 viafb_mmio_write(VDE_INTERRUPT, 0);  /* Disable entirely */
  90         else
  91                 viafb_mmio_write(VDE_INTERRUPT,
  92                                 viafb_enabled_ints | VDE_I_ENABLE);
  93 }
  94 EXPORT_SYMBOL_GPL(viafb_irq_disable);
  95
  96 /* ---------------------------------------------------------------------- */
  97 /*
  98  * Access to the DMA engine.  This currently provides what the camera
  99  * driver needs (i.e. outgoing only) but is easily expandable if need
 100  * be.
 101  */
 102
 103 /*
 104  * There are four DMA channels in the vx855.  For now, we only
 105  * use one of them, though.  Most of the time, the DMA channel
 106  * will be idle, so we keep the IRQ handler unregistered except
 107  * when some subsystem has indicated an interest.
 108  */
 109 static int viafb_dma_users;
 110 static DECLARE_COMPLETION(viafb_dma_completion);
 111 /*
 112  * This mutex protects viafb_dma_users and our global interrupt
 113  * registration state; it also serializes access to the DMA
 114  * engine.
 115  */
 116 static DEFINE_MUTEX(viafb_dma_lock);
 117
 118 /*
 119  * The VX855 DMA descriptor (used for s/g transfers) looks
 120  * like this.
 121  */
 122 struct viafb_vx855_dma_descr {
 123         u32     addr_low;       /* Low part of phys addr */
 124         u32     addr_high;      /* High 12 bits of addr */
 125         u32     fb_offset;      /* Offset into FB memory */
 126         u32     seg_size;       /* Size, 16-byte units */
 127         u32     tile_mode;      /* "tile mode" setting */
 128         u32     next_desc_low;  /* Next descriptor addr */
 129         u32     next_desc_high;
 130         u32     pad;            /* Fill out to 64 bytes */
 131 };
 132
 133 /*
 134  * Flags added to the "next descriptor low" pointers
 135  */
 136 #define VIAFB_DMA_MAGIC         0x01  /* ??? Just has to be there */
 137 #define VIAFB_DMA_FINAL_SEGMENT 0x02  /* Final segment */
 138
 139 /*
 140  * The completion IRQ handler.
 141  */
 142 static irqreturn_t viafb_dma_irq(int irq, void *data)
 143 {
 144         int csr;
 145         irqreturn_t ret = IRQ_NONE;
 146
 147         spin_lock(&global_dev.reg_lock);
 148         csr = viafb_mmio_read(VDMA_CSR0);
 149         if (csr & VDMA_C_DONE) {
 150                 viafb_mmio_write(VDMA_CSR0, VDMA_C_DONE);
 151                 complete(&viafb_dma_completion);
 152                 ret = IRQ_HANDLED;
 153         }
 154         spin_unlock(&global_dev.reg_lock);
 155         return ret;
 156 }
 157
 158 /*
 159  * Indicate a need for DMA functionality.
 160  */
 161 int viafb_request_dma(void)
 162 {
 163         int ret = 0;
 164
 165         /*
 166          * Only VX855 is supported currently.
 167          */
 168         if (global_dev.chip_type != UNICHROME_VX855)
 169                 return -ENODEV;
 170         /*
 171          * Note the new user and set up our interrupt handler
 172          * if need be.
 173          */
 174         mutex_lock(&viafb_dma_lock);
 175         viafb_dma_users++;
 176         if (viafb_dma_users == 1) {
 177                 ret = request_irq(global_dev.pdev->irq, viafb_dma_irq,
 178                                 IRQF_SHARED, "via-dma", &viafb_dma_users);
 179                 if (ret)
 180                         viafb_dma_users--;
 181                 else
 182                         viafb_irq_enable(VDE_I_DMA0TDEN);
 183         }
 184         mutex_unlock(&viafb_dma_lock);
 185         return ret;
 186 }
 187 EXPORT_SYMBOL_GPL(viafb_request_dma);
 188
 189 void viafb_release_dma(void)
 190 {
 191         mutex_lock(&viafb_dma_lock);
 192         viafb_dma_users--;
 193         if (viafb_dma_users == 0) {
 194                 viafb_irq_disable(VDE_I_DMA0TDEN);
 195                 free_irq(global_dev.pdev->irq, &viafb_dma_users);
 196         }
 197         mutex_unlock(&viafb_dma_lock);
 198 }
 199 EXPORT_SYMBOL_GPL(viafb_release_dma);
 200
 201
 202
 203 /*
 204  * Do a scatter/gather DMA copy from FB memory.  You must have done
 205  * a successful call to viafb_request_dma() first.
 206  */
 207 int viafb_dma_copy_out_sg(unsigned int offset, struct scatterlist *sg, int nsg)
 208 {
 209         struct viafb_vx855_dma_descr *descr;
 210         void *descrpages;
 211         dma_addr_t descr_handle;
 212         unsigned long flags;
 213         int i;
 214         struct scatterlist *sgentry;
 215         dma_addr_t nextdesc;
 216
 217         /*
 218          * Get a place to put the descriptors.
 219          */
 220         descrpages = dma_alloc_coherent(&global_dev.pdev->dev,
 221                         nsg*sizeof(struct viafb_vx855_dma_descr),
 222                         &descr_handle, GFP_KERNEL);
 223         if (descrpages == NULL) {
 224                 dev_err(&global_dev.pdev->dev, "Unable to get descr page.\n");
 225                 return -ENOMEM;
 226         }
 227         mutex_lock(&viafb_dma_lock);
 228         /*
 229          * Fill them in.
 230          */
 231         descr = descrpages;
 232         nextdesc = descr_handle + sizeof(struct viafb_vx855_dma_descr);
 233         for_each_sg(sg, sgentry, nsg, i) {
 234                 dma_addr_t paddr = sg_dma_address(sgentry);
 235                 descr->addr_low = paddr & 0xfffffff0;
 236                 descr->addr_high = ((u64) paddr >> 32) & 0x0fff;
 237                 descr->fb_offset = offset;
 238                 descr->seg_size = sg_dma_len(sgentry) >> 4;
 239                 descr->tile_mode = 0;
 240                 descr->next_desc_low = (nextdesc&0xfffffff0) | VIAFB_DMA_MAGIC;
 241                 descr->next_desc_high = ((u64) nextdesc >> 32) & 0x0fff;
 242                 descr->pad = 0xffffffff;  /* VIA driver does this */
 243                 offset += sg_dma_len(sgentry);
 244                 nextdesc += sizeof(struct viafb_vx855_dma_descr);
 245                 descr++;
 246         }
 247         descr[-1].next_desc_low = VIAFB_DMA_FINAL_SEGMENT|VIAFB_DMA_MAGIC;
 248         /*
 249          * Program the engine.
 250          */
 251         spin_lock_irqsave(&global_dev.reg_lock, flags);
 252         init_completion(&viafb_dma_completion);
 253         viafb_mmio_write(VDMA_DQWCR0, 0);
 254         viafb_mmio_write(VDMA_CSR0, VDMA_C_ENABLE|VDMA_C_DONE);
 255         viafb_mmio_write(VDMA_MR0, VDMA_MR_TDIE | VDMA_MR_CHAIN);
 256         viafb_mmio_write(VDMA_DPRL0, descr_handle | VIAFB_DMA_MAGIC);
 257         viafb_mmio_write(VDMA_DPRH0,
 258                         (((u64)descr_handle >> 32) & 0x0fff) | 0xf0000);
 259         (void) viafb_mmio_read(VDMA_CSR0);
 260         viafb_mmio_write(VDMA_CSR0, VDMA_C_ENABLE|VDMA_C_START);
 261         spin_unlock_irqrestore(&global_dev.reg_lock, flags);
 262         /*
 263          * Now we just wait until the interrupt handler says
 264          * we're done.  Except that, actually, we need to wait a little
 265          * longer: the interrupts seem to jump the gun a little and we
 266          * get corrupted frames sometimes.
 267          */
 268         wait_for_completion_timeout(&viafb_dma_completion, 1);
 269         msleep(1);
 270         if ((viafb_mmio_read(VDMA_CSR0)&VDMA_C_DONE) == 0)
 271                 printk(KERN_ERR "VIA DMA timeout!\n");
 272         /*
 273          * Clean up and we're done.
 274          */
 275         viafb_mmio_write(VDMA_CSR0, VDMA_C_DONE);
 276         viafb_mmio_write(VDMA_MR0, 0); /* Reset int enable */
 277         mutex_unlock(&viafb_dma_lock);
 278         dma_free_coherent(&global_dev.pdev->dev,
 279                         nsg*sizeof(struct viafb_vx855_dma_descr), descrpages,
 280                         descr_handle);
 281         return 0;
 282 }
 283 EXPORT_SYMBOL_GPL(viafb_dma_copy_out_sg);
 284
 285
 286 /* ---------------------------------------------------------------------- */
 287 /*
 288  * Figure out how big our framebuffer memory is.  Kind of ugly,
 289  * but evidently we can't trust the information found in the
 290  * fbdev configuration area.
 291  */
 292 static u16 via_function3[] = {
 293         CLE266_FUNCTION3, KM400_FUNCTION3, CN400_FUNCTION3, CN700_FUNCTION3,
 294         CX700_FUNCTION3, KM800_FUNCTION3, KM890_FUNCTION3, P4M890_FUNCTION3,
 295         P4M900_FUNCTION3, VX800_FUNCTION3, VX855_FUNCTION3,
 296 };
 297
 298 /* Get the BIOS-configured framebuffer size from PCI configuration space
 299  * of function 3 in the respective chipset */
 300 static int viafb_get_fb_size_from_pci(int chip_type)
 301 {
 302         int i;
 303         u8 offset = 0;
 304         u32 FBSize;
 305         u32 VideoMemSize;
 306
 307         /* search for the "FUNCTION3" device in this chipset */
 308         for (i = 0; i < ARRAY_SIZE(via_function3); i++) {
 309                 struct pci_dev *pdev;
 310
 311                 pdev = pci_get_device(PCI_VENDOR_ID_VIA, via_function3[i],
 312                                       NULL);
 313                 if (!pdev)
 314                         continue;
 315
 316                 DEBUG_MSG(KERN_INFO "Device ID = %x\n", pdev->device);
 317
 318                 switch (pdev->device) {
 319                 case CLE266_FUNCTION3:
 320                 case KM400_FUNCTION3:
 321                         offset = 0xE0;
 322                         break;
 323                 case CN400_FUNCTION3:
 324                 case CN700_FUNCTION3:
 325                 case CX700_FUNCTION3:
 326                 case KM800_FUNCTION3:
 327                 case KM890_FUNCTION3:
 328                 case P4M890_FUNCTION3:
 329                 case P4M900_FUNCTION3:
 330                 case VX800_FUNCTION3:
 331                 case VX855_FUNCTION3:
 332                 /*case CN750_FUNCTION3: */
 333                         offset = 0xA0;
 334                         break;
 335                 }
 336
 337                 if (!offset)
 338                         break;
 339
 340                 pci_read_config_dword(pdev, offset, &FBSize);
 341                 pci_dev_put(pdev);
 342         }
 343
 344         if (!offset) {
 345                 printk(KERN_ERR "cannot determine framebuffer size\n");
 346                 return -EIO;
 347         }
 348
 349         FBSize = FBSize & 0x00007000;
 350         DEBUG_MSG(KERN_INFO "FB Size = %x\n", FBSize);
 351
 352         if (chip_type < UNICHROME_CX700) {
 353                 switch (FBSize) {
 354                 case 0x00004000:
 355                         VideoMemSize = (16 << 20);      /*16M */
 356                         break;
 357
 358                 case 0x00005000:
 359                         VideoMemSize = (32 << 20);      /*32M */
 360                         break;
 361
 362                 case 0x00006000:
 363                         VideoMemSize = (64 << 20);      /*64M */
 364                         break;
 365
 366                 default:
 367                         VideoMemSize = (32 << 20);      /*32M */
 368                         break;
 369                 }
 370         } else {
 371                 switch (FBSize) {
 372                 case 0x00001000:
 373                         VideoMemSize = (8 << 20);       /*8M */
 374                         break;
 375
 376                 case 0x00002000:
 377                         VideoMemSize = (16 << 20);      /*16M */
 378                         break;
 379
 380                 case 0x00003000:
 381                         VideoMemSize = (32 << 20);      /*32M */
 382                         break;
 383
 384                 case 0x00004000:
 385                         VideoMemSize = (64 << 20);      /*64M */
 386                         break;
 387
 388                 case 0x00005000:
 389                         VideoMemSize = (128 << 20);     /*128M */
 390                         break;
 391
 392                 case 0x00006000:
 393                         VideoMemSize = (256 << 20);     /*256M */
 394                         break;
 395
 396                 case 0x00007000:        /* Only on VX855/875 */
 397                         VideoMemSize = (512 << 20);     /*512M */
 398                         break;
 399
 400                 default:
 401                         VideoMemSize = (32 << 20);      /*32M */
 402                         break;
 403                 }
 404         }
 405
 406         return VideoMemSize;
 407 }
 408
 409
 410 /*
 411  * Figure out and map our MMIO regions.
 412  */
 413 static int __devinit via_pci_setup_mmio(struct viafb_dev *vdev)
 414 {
 415         int ret;
 416         /*
 417          * Hook up to the device registers.  Note that we soldier
 418          * on if it fails; the framebuffer can operate (without
 419          * acceleration) without this region.
 420          */
 421         vdev->engine_start = pci_resource_start(vdev->pdev, 1);
 422         vdev->engine_len = pci_resource_len(vdev->pdev, 1);
 423         vdev->engine_mmio = ioremap_nocache(vdev->engine_start,
 424                         vdev->engine_len);
 425         if (vdev->engine_mmio == NULL)
 426                 dev_err(&vdev->pdev->dev,
 427                                 "Unable to map engine MMIO; operation will be "
 428                                 "slow and crippled.\n");
 429         /*
 430          * Map in framebuffer memory.  For now, failure here is
 431          * fatal.  Unfortunately, in the absence of significant
 432          * vmalloc space, failure here is also entirely plausible.
 433          * Eventually we want to move away from mapping this
 434          * entire region.
 435          */
 436         vdev->fbmem_start = pci_resource_start(vdev->pdev, 0);
 437         ret = vdev->fbmem_len = viafb_get_fb_size_from_pci(vdev->chip_type);
 438         if (ret < 0)
 439                 goto out_unmap;
 440         vdev->fbmem = ioremap_nocache(vdev->fbmem_start, vdev->fbmem_len);
 441         if (vdev->fbmem == NULL) {
 442                 ret = -ENOMEM;
 443                 goto out_unmap;
 444         }
 445         return 0;
 446 out_unmap:
 447         iounmap(vdev->engine_mmio);
 448         return ret;
 449 }
 450
 451 static void via_pci_teardown_mmio(struct viafb_dev *vdev)
 452 {
 453         iounmap(vdev->fbmem);
 454         iounmap(vdev->engine_mmio);
 455 }
 456
 457 /*
 458  * Create our subsidiary devices.
 459  */
 460 static struct viafb_subdev_info {
 461         char *name;
 462         struct platform_device *platdev;
 463 } viafb_subdevs[] = {
 464         {
 465                 .name = "viafb-gpio",
 466         },
 467         {
 468                 .name = "viafb-i2c",
 469         }
 470 };
 471 #define N_SUBDEVS ARRAY_SIZE(viafb_subdevs)
 472
 473 static int __devinit via_create_subdev(struct viafb_dev *vdev,
 474                 struct viafb_subdev_info *info)
 475 {
 476         int ret;
 477
 478         info->platdev = platform_device_alloc(info->name, -1);
 479         if (!info->platdev) {
 480                 dev_err(&vdev->pdev->dev, "Unable to allocate pdev %s\n",
 481                         info->name);
 482                 return -ENOMEM;
 483         }
 484         info->platdev->dev.parent = &vdev->pdev->dev;
 485         info->platdev->dev.platform_data = vdev;
 486         ret = platform_device_add(info->platdev);
 487         if (ret) {
 488                 dev_err(&vdev->pdev->dev, "Unable to add pdev %s\n",
 489                                 info->name);
 490                 platform_device_put(info->platdev);
 491                 info->platdev = NULL;
 492         }
 493         return ret;
 494 }
 495
 496 static int __devinit via_setup_subdevs(struct viafb_dev *vdev)
 497 {
 498         int i;
 499
 500         /*
 501          * Ignore return values.  Even if some of the devices
 502          * fail to be created, we'll still be able to use some
 503          * of the rest.
 504          */
 505         for (i = 0; i < N_SUBDEVS; i++)
 506                 via_create_subdev(vdev, viafb_subdevs + i);
 507         return 0;
 508 }
 509
 510 static void via_teardown_subdevs(void)
 511 {
 512         int i;
 513
 514         for (i = 0; i < N_SUBDEVS; i++)
 515                 if (viafb_subdevs[i].platdev) {
 516                         viafb_subdevs[i].platdev->dev.platform_data = NULL;
 517                         platform_device_unregister(viafb_subdevs[i].platdev);
 518                 }
 519 }
 520
 521
 522 static int __devinit via_pci_probe(struct pci_dev *pdev,
 523                 const struct pci_device_id *ent)
 524 {
 525         int ret;
 526
 527         ret = pci_enable_device(pdev);
 528         if (ret)
 529                 return ret;
 530         /*
 531          * Global device initialization.
 532          */
 533         memset(&global_dev, 0, sizeof(global_dev));
 534         global_dev.pdev = pdev;
 535         global_dev.chip_type = ent->driver_data;
 536         global_dev.port_cfg = adap_configs;
 537         spin_lock_init(&global_dev.reg_lock);
 538         ret = via_pci_setup_mmio(&global_dev);
 539         if (ret)
 540                 goto out_disable;
 541         /*
 542          * Set up interrupts and create our subdevices.  Continue even if
 543          * some things fail.
 544          */
 545         viafb_int_init();
 546         via_setup_subdevs(&global_dev);
 547         /*
 548          * Set up the framebuffer device
 549          */
 550         ret = via_fb_pci_probe(&global_dev);
 551         if (ret)
 552                 goto out_subdevs;
 553         return 0;
 554
 555 out_subdevs:
 556         via_teardown_subdevs();
 557         via_pci_teardown_mmio(&global_dev);
 558 out_disable:
 559         pci_disable_device(pdev);
 560         return ret;
 561 }
 562
 563 static void __devexit via_pci_remove(struct pci_dev *pdev)
 564 {
 565         via_teardown_subdevs();
 566         via_fb_pci_remove(pdev);
 567         via_pci_teardown_mmio(&global_dev);
 568         pci_disable_device(pdev);
 569 }
 570
 571
 572 static struct pci_device_id via_pci_table[] __devinitdata = {
 573         { PCI_DEVICE(PCI_VENDOR_ID_VIA, UNICHROME_CLE266_DID),
 574           .driver_data = UNICHROME_CLE266 },
 575         { PCI_DEVICE(PCI_VENDOR_ID_VIA, UNICHROME_K400_DID),
 576           .driver_data = UNICHROME_K400 },
 577         { PCI_DEVICE(PCI_VENDOR_ID_VIA, UNICHROME_K800_DID),
 578           .driver_data = UNICHROME_K800 },
 579         { PCI_DEVICE(PCI_VENDOR_ID_VIA, UNICHROME_PM800_DID),
 580           .driver_data = UNICHROME_PM800 },
 581         { PCI_DEVICE(PCI_VENDOR_ID_VIA, UNICHROME_CN700_DID),
 582           .driver_data = UNICHROME_CN700 },
 583         { PCI_DEVICE(PCI_VENDOR_ID_VIA, UNICHROME_CX700_DID),
 584           .driver_data = UNICHROME_CX700 },
 585         { PCI_DEVICE(PCI_VENDOR_ID_VIA, UNICHROME_CN750_DID),
 586           .driver_data = UNICHROME_CN750 },
 587         { PCI_DEVICE(PCI_VENDOR_ID_VIA, UNICHROME_K8M890_DID),
 588           .driver_data = UNICHROME_K8M890 },
 589         { PCI_DEVICE(PCI_VENDOR_ID_VIA, UNICHROME_P4M890_DID),
 590           .driver_data = UNICHROME_P4M890 },
 591         { PCI_DEVICE(PCI_VENDOR_ID_VIA, UNICHROME_P4M900_DID),
 592           .driver_data = UNICHROME_P4M900 },
 593         { PCI_DEVICE(PCI_VENDOR_ID_VIA, UNICHROME_VX800_DID),
 594           .driver_data = UNICHROME_VX800 },
 595         { PCI_DEVICE(PCI_VENDOR_ID_VIA, UNICHROME_VX855_DID),
 596           .driver_data = UNICHROME_VX855 },
 597         { }
 598 };
 599 MODULE_DEVICE_TABLE(pci, via_pci_table);
 600
 601 static struct pci_driver via_driver = {
 602         .name           = "viafb",
 603         .id_table       = via_pci_table,
 604         .probe          = via_pci_probe,
 605         .remove         = __devexit_p(via_pci_remove),
 606 };
 607
 608 static int __init via_core_init(void)
 609 {
 610         int ret;
 611
 612         ret = viafb_init();
 613         if (ret)
 614                 return ret;
 615         viafb_i2c_init();
 616         viafb_gpio_init();
 617         return pci_register_driver(&via_driver);
 618 }
 619
 620 static void __exit via_core_exit(void)
 621 {
 622         pci_unregister_driver(&via_driver);
 623         viafb_gpio_exit();
 624         viafb_i2c_exit();
 625         viafb_exit();
 626 }
 627
 628 module_init(via_core_init);
 629 module_exit(via_core_exit);