drivers/ata/sata_via.c

   1 /*
   2  *  sata_via.c - VIA Serial ATA controllers
   3  *
   4  *  Maintained by:  Jeff Garzik <jgarzik@pobox.com>
   5  *                 Please ALWAYS copy linux-ide@vger.kernel.org
   6  *                 on emails.
   7  *
   8  *  Copyright 2003-2004 Red Hat, Inc.  All rights reserved.
   9  *  Copyright 2003-2004 Jeff Garzik
  10  *
  11  *
  12  *  This program is free software; you can redistribute it and/or modify
  13  *  it under the terms of the GNU General Public License as published by
  14  *  the Free Software Foundation; either version 2, or (at your option)
  15  *  any later version.
  16  *
  17  *  This program is distributed in the hope that it will be useful,
  18  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  *  GNU General Public License for more details.
  21  *
  22  *  You should have received a copy of the GNU General Public License
  23  *  along with this program; see the file COPYING.  If not, write to
  24  *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  25  *
  26  *
  27  *  libata documentation is available via 'make {ps|pdf}docs',
  28  *  as Documentation/DocBook/libata.*
  29  *
  30  *  Hardware documentation available under NDA.
  31  *
  32  *
  33  *
  34  */
  35
  36 #include <linux/kernel.h>
  37 #include <linux/module.h>
  38 #include <linux/pci.h>
  39 #include <linux/init.h>
  40 #include <linux/blkdev.h>
  41 #include <linux/delay.h>
  42 #include <linux/device.h>
  43 #include <scsi/scsi.h>
  44 #include <scsi/scsi_cmnd.h>
  45 #include <scsi/scsi_host.h>
  46 #include <linux/libata.h>
  47
  48 #define DRV_NAME        "sata_via"
  49 #define DRV_VERSION     "2.6"
  50
  51 /*
  52  * vt8251 is different from other sata controllers of VIA.  It has two
  53  * channels, each channel has both Master and Slave slot.
  54  */
  55 enum board_ids_enum {
  56         vt6420,
  57         vt6421,
  58         vt8251,
  59 };
  60
  61 enum {
  62         SATA_CHAN_ENAB          = 0x40, /* SATA channel enable */
  63         SATA_INT_GATE           = 0x41, /* SATA interrupt gating */
  64         SATA_NATIVE_MODE        = 0x42, /* Native mode enable */
  65         PATA_UDMA_TIMING        = 0xB3, /* PATA timing for DMA/ cable detect */
  66         PATA_PIO_TIMING         = 0xAB, /* PATA timing register */
  67
  68         PORT0                   = (1 << 1),
  69         PORT1                   = (1 << 0),
  70         ALL_PORTS               = PORT0 | PORT1,
  71
  72         NATIVE_MODE_ALL         = (1 << 7) | (1 << 6) | (1 << 5) | (1 << 4),
  73
  74         SATA_EXT_PHY            = (1 << 6), /* 0==use PATA, 1==ext phy */
  75 };
  76
  77 static int svia_init_one(struct pci_dev *pdev, const struct pci_device_id *ent);
  78 static int svia_scr_read(struct ata_link *link, unsigned int sc_reg, u32 *val);
  79 static int svia_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val);
  80 static int vt8251_scr_read(struct ata_link *link, unsigned int scr, u32 *val);
  81 static int vt8251_scr_write(struct ata_link *link, unsigned int scr, u32 val);
  82 static void svia_tf_load(struct ata_port *ap, const struct ata_taskfile *tf);
  83 static void svia_noop_freeze(struct ata_port *ap);
  84 static int vt6420_prereset(struct ata_link *link, unsigned long deadline);
  85 static void vt6420_bmdma_start(struct ata_queued_cmd *qc);
  86 static int vt6421_pata_cable_detect(struct ata_port *ap);
  87 static void vt6421_set_pio_mode(struct ata_port *ap, struct ata_device *adev);
  88 static void vt6421_set_dma_mode(struct ata_port *ap, struct ata_device *adev);
  89
  90 static const struct pci_device_id svia_pci_tbl[] = {
  91         { PCI_VDEVICE(VIA, 0x5337), vt6420 },
  92         { PCI_VDEVICE(VIA, 0x0591), vt6420 }, /* 2 sata chnls (Master) */
  93         { PCI_VDEVICE(VIA, 0x3149), vt6420 }, /* 2 sata chnls (Master) */
  94         { PCI_VDEVICE(VIA, 0x3249), vt6421 }, /* 2 sata chnls, 1 pata chnl */
  95         { PCI_VDEVICE(VIA, 0x5372), vt6420 },
  96         { PCI_VDEVICE(VIA, 0x7372), vt6420 },
  97         { PCI_VDEVICE(VIA, 0x5287), vt8251 }, /* 2 sata chnls (Master/Slave) */
  98         { PCI_VDEVICE(VIA, 0x9000), vt8251 },
  99
 100         { }     /* terminate list */
 101 };
 102
 103 static struct pci_driver svia_pci_driver = {
 104         .name                   = DRV_NAME,
 105         .id_table               = svia_pci_tbl,
 106         .probe                  = svia_init_one,
 107 #ifdef CONFIG_PM
 108         .suspend                = ata_pci_device_suspend,
 109         .resume                 = ata_pci_device_resume,
 110 #endif
 111         .remove                 = ata_pci_remove_one,
 112 };
 113
 114 static struct scsi_host_template svia_sht = {
 115         ATA_BMDMA_SHT(DRV_NAME),
 116 };
 117
 118 static struct ata_port_operations svia_base_ops = {
 119         .inherits               = &ata_bmdma_port_ops,
 120         .sff_tf_load            = svia_tf_load,
 121 };
 122
 123 static struct ata_port_operations vt6420_sata_ops = {
 124         .inherits               = &svia_base_ops,
 125         .freeze                 = svia_noop_freeze,
 126         .prereset               = vt6420_prereset,
 127         .bmdma_start            = vt6420_bmdma_start,
 128 };
 129
 130 static struct ata_port_operations vt6421_pata_ops = {
 131         .inherits               = &svia_base_ops,
 132         .cable_detect           = vt6421_pata_cable_detect,
 133         .set_piomode            = vt6421_set_pio_mode,
 134         .set_dmamode            = vt6421_set_dma_mode,
 135 };
 136
 137 static struct ata_port_operations vt6421_sata_ops = {
 138         .inherits               = &svia_base_ops,
 139         .scr_read               = svia_scr_read,
 140         .scr_write              = svia_scr_write,
 141 };
 142
 143 static struct ata_port_operations vt8251_ops = {
 144         .inherits               = &svia_base_ops,
 145         .hardreset              = sata_std_hardreset,
 146         .scr_read               = vt8251_scr_read,
 147         .scr_write              = vt8251_scr_write,
 148 };
 149
 150 static const struct ata_port_info vt6420_port_info = {
 151         .flags          = ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY,
 152         .pio_mask       = ATA_PIO4,
 153         .mwdma_mask     = ATA_MWDMA2,
 154         .udma_mask      = ATA_UDMA6,
 155         .port_ops       = &vt6420_sata_ops,
 156 };
 157
 158 static struct ata_port_info vt6421_sport_info = {
 159         .flags          = ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY,
 160         .pio_mask       = ATA_PIO4,
 161         .mwdma_mask     = ATA_MWDMA2,
 162         .udma_mask      = ATA_UDMA6,
 163         .port_ops       = &vt6421_sata_ops,
 164 };
 165
 166 static struct ata_port_info vt6421_pport_info = {
 167         .flags          = ATA_FLAG_SLAVE_POSS | ATA_FLAG_NO_LEGACY,
 168         .pio_mask       = ATA_PIO4,
 169         /* No MWDMA */
 170         .udma_mask      = ATA_UDMA6,
 171         .port_ops       = &vt6421_pata_ops,
 172 };
 173
 174 static struct ata_port_info vt8251_port_info = {
 175         .flags          = ATA_FLAG_SATA | ATA_FLAG_SLAVE_POSS |
 176                           ATA_FLAG_NO_LEGACY,
 177         .pio_mask       = ATA_PIO4,
 178         .mwdma_mask     = ATA_MWDMA2,
 179         .udma_mask      = ATA_UDMA6,
 180         .port_ops       = &vt8251_ops,
 181 };
 182
 183 MODULE_AUTHOR("Jeff Garzik");
 184 MODULE_DESCRIPTION("SCSI low-level driver for VIA SATA controllers");
 185 MODULE_LICENSE("GPL");
 186 MODULE_DEVICE_TABLE(pci, svia_pci_tbl);
 187 MODULE_VERSION(DRV_VERSION);
 188
 189 static int svia_scr_read(struct ata_link *link, unsigned int sc_reg, u32 *val)
 190 {
 191         if (sc_reg > SCR_CONTROL)
 192                 return -EINVAL;
 193         *val = ioread32(link->ap->ioaddr.scr_addr + (4 * sc_reg));
 194         return 0;
 195 }
 196
 197 static int svia_scr_write(struct ata_link *link, unsigned int sc_reg, u32 val)
 198 {
 199         if (sc_reg > SCR_CONTROL)
 200                 return -EINVAL;
 201         iowrite32(val, link->ap->ioaddr.scr_addr + (4 * sc_reg));
 202         return 0;
 203 }
 204
 205 static int vt8251_scr_read(struct ata_link *link, unsigned int scr, u32 *val)
 206 {
 207         static const u8 ipm_tbl[] = { 1, 2, 6, 0 };
 208         struct pci_dev *pdev = to_pci_dev(link->ap->host->dev);
 209         int slot = 2 * link->ap->port_no + link->pmp;
 210         u32 v = 0;
 211         u8 raw;
 212
 213         switch (scr) {
 214         case SCR_STATUS:
 215                 pci_read_config_byte(pdev, 0xA0 + slot, &raw);
 216
 217                 /* read the DET field, bit0 and 1 of the config byte */
 218                 v |= raw & 0x03;
 219
 220                 /* read the SPD field, bit4 of the configure byte */
 221                 if (raw & (1 << 4))
 222                         v |= 0x02 << 4;
 223                 else
 224                         v |= 0x01 << 4;
 225
 226                 /* read the IPM field, bit2 and 3 of the config byte */
 227                 v |= ipm_tbl[(raw >> 2) & 0x3];
 228                 break;
 229
 230         case SCR_ERROR:
 231                 /* devices other than 5287 uses 0xA8 as base */
 232                 WARN_ON(pdev->device != 0x5287);
 233                 pci_read_config_dword(pdev, 0xB0 + slot * 4, &v);
 234                 break;
 235
 236         case SCR_CONTROL:
 237                 pci_read_config_byte(pdev, 0xA4 + slot, &raw);
 238
 239                 /* read the DET field, bit0 and bit1 */
 240                 v |= ((raw & 0x02) << 1) | (raw & 0x01);
 241
 242                 /* read the IPM field, bit2 and bit3 */
 243                 v |= ((raw >> 2) & 0x03) << 8;
 244                 break;
 245
 246         default:
 247                 return -EINVAL;
 248         }
 249
 250         *val = v;
 251         return 0;
 252 }
 253
 254 static int vt8251_scr_write(struct ata_link *link, unsigned int scr, u32 val)
 255 {
 256         struct pci_dev *pdev = to_pci_dev(link->ap->host->dev);
 257         int slot = 2 * link->ap->port_no + link->pmp;
 258         u32 v = 0;
 259
 260         switch (scr) {
 261         case SCR_ERROR:
 262                 /* devices other than 5287 uses 0xA8 as base */
 263                 WARN_ON(pdev->device != 0x5287);
 264                 pci_write_config_dword(pdev, 0xB0 + slot * 4, val);
 265                 return 0;
 266
 267         case SCR_CONTROL:
 268                 /* set the DET field */
 269                 v |= ((val & 0x4) >> 1) | (val & 0x1);
 270
 271                 /* set the IPM field */
 272                 v |= ((val >> 8) & 0x3) << 2;
 273
 274                 pci_write_config_byte(pdev, 0xA4 + slot, v);
 275                 return 0;
 276
 277         default:
 278                 return -EINVAL;
 279         }
 280 }
 281
 282 /**
 283  *      svia_tf_load - send taskfile registers to host controller
 284  *      @ap: Port to which output is sent
 285  *      @tf: ATA taskfile register set
 286  *
 287  *      Outputs ATA taskfile to standard ATA host controller.
 288  *
 289  *      This is to fix the internal bug of via chipsets, which will
 290  *      reset the device register after changing the IEN bit on ctl
 291  *      register.
 292  */
 293 static void svia_tf_load(struct ata_port *ap, const struct ata_taskfile *tf)
 294 {
 295         struct ata_taskfile ttf;
 296
 297         if (tf->ctl != ap->last_ctl)  {
 298                 ttf = *tf;
 299                 ttf.flags |= ATA_TFLAG_DEVICE;
 300                 tf = &ttf;
 301         }
 302         ata_sff_tf_load(ap, tf);
 303 }
 304
 305 static void svia_noop_freeze(struct ata_port *ap)
 306 {
 307         /* Some VIA controllers choke if ATA_NIEN is manipulated in
 308          * certain way.  Leave it alone and just clear pending IRQ.
 309          */
 310         ap->ops->sff_check_status(ap);
 311         ata_bmdma_irq_clear(ap);
 312 }
 313
 314 /**
 315  *      vt6420_prereset - prereset for vt6420
 316  *      @link: target ATA link
 317  *      @deadline: deadline jiffies for the operation
 318  *
 319  *      SCR registers on vt6420 are pieces of shit and may hang the
 320  *      whole machine completely if accessed with the wrong timing.
 321  *      To avoid such catastrophe, vt6420 doesn't provide generic SCR
 322  *      access operations, but uses SStatus and SControl only during
 323  *      boot probing in controlled way.
 324  *
 325  *      As the old (pre EH update) probing code is proven to work, we
 326  *      strictly follow the access pattern.
 327  *
 328  *      LOCKING:
 329  *      Kernel thread context (may sleep)
 330  *
 331  *      RETURNS:
 332  *      0 on success, -errno otherwise.
 333  */
 334 static int vt6420_prereset(struct ata_link *link, unsigned long deadline)
 335 {
 336         struct ata_port *ap = link->ap;
 337         struct ata_eh_context *ehc = &ap->link.eh_context;
 338         unsigned long timeout = jiffies + (HZ * 5);
 339         u32 sstatus, scontrol;
 340         int online;
 341
 342         /* don't do any SCR stuff if we're not loading */
 343         if (!(ap->pflags & ATA_PFLAG_LOADING))
 344                 goto skip_scr;
 345
 346         /* Resume phy.  This is the old SATA resume sequence */
 347         svia_scr_write(link, SCR_CONTROL, 0x300);
 348         svia_scr_read(link, SCR_CONTROL, &scontrol); /* flush */
 349
 350         /* wait for phy to become ready, if necessary */
 351         do {
 352                 msleep(200);
 353                 svia_scr_read(link, SCR_STATUS, &sstatus);
 354                 if ((sstatus & 0xf) != 1)
 355                         break;
 356         } while (time_before(jiffies, timeout));
 357
 358         /* open code sata_print_link_status() */
 359         svia_scr_read(link, SCR_STATUS, &sstatus);
 360         svia_scr_read(link, SCR_CONTROL, &scontrol);
 361
 362         online = (sstatus & 0xf) == 0x3;
 363
 364         ata_port_printk(ap, KERN_INFO,
 365                         "SATA link %s 1.5 Gbps (SStatus %X SControl %X)\n",
 366                         online ? "up" : "down", sstatus, scontrol);
 367
 368         /* SStatus is read one more time */
 369         svia_scr_read(link, SCR_STATUS, &sstatus);
 370
 371         if (!online) {
 372                 /* tell EH to bail */
 373                 ehc->i.action &= ~ATA_EH_RESET;
 374                 return 0;
 375         }
 376
 377  skip_scr:
 378         /* wait for !BSY */
 379         ata_sff_wait_ready(link, deadline);
 380
 381         return 0;
 382 }
 383
 384 static void vt6420_bmdma_start(struct ata_queued_cmd *qc)
 385 {
 386         struct ata_port *ap = qc->ap;
 387         if ((qc->tf.command == ATA_CMD_PACKET) &&
 388             (qc->scsicmd->sc_data_direction == DMA_TO_DEVICE)) {
 389                 /* Prevents corruption on some ATAPI burners */
 390                 ata_sff_pause(ap);
 391         }
 392         ata_bmdma_start(qc);
 393 }
 394
 395 static int vt6421_pata_cable_detect(struct ata_port *ap)
 396 {
 397         struct pci_dev *pdev = to_pci_dev(ap->host->dev);
 398         u8 tmp;
 399
 400         pci_read_config_byte(pdev, PATA_UDMA_TIMING, &tmp);
 401         if (tmp & 0x10)
 402                 return ATA_CBL_PATA40;
 403         return ATA_CBL_PATA80;
 404 }
 405
 406 static void vt6421_set_pio_mode(struct ata_port *ap, struct ata_device *adev)
 407 {
 408         struct pci_dev *pdev = to_pci_dev(ap->host->dev);
 409         static const u8 pio_bits[] = { 0xA8, 0x65, 0x65, 0x31, 0x20 };
 410         pci_write_config_byte(pdev, PATA_PIO_TIMING - adev->devno,
 411                               pio_bits[adev->pio_mode - XFER_PIO_0]);
 412 }
 413
 414 static void vt6421_set_dma_mode(struct ata_port *ap, struct ata_device *adev)
 415 {
 416         struct pci_dev *pdev = to_pci_dev(ap->host->dev);
 417         static const u8 udma_bits[] = { 0xEE, 0xE8, 0xE6, 0xE4, 0xE2, 0xE1, 0xE0, 0xE0 };
 418         pci_write_config_byte(pdev, PATA_UDMA_TIMING - adev->devno,
 419                               udma_bits[adev->dma_mode - XFER_UDMA_0]);
 420 }
 421
 422 static const unsigned int svia_bar_sizes[] = {
 423         8, 4, 8, 4, 16, 256
 424 };
 425
 426 static const unsigned int vt6421_bar_sizes[] = {
 427         16, 16, 16, 16, 32, 128
 428 };
 429
 430 static void __iomem *svia_scr_addr(void __iomem *addr, unsigned int port)
 431 {
 432         return addr + (port * 128);
 433 }
 434
 435 static void __iomem *vt6421_scr_addr(void __iomem *addr, unsigned int port)
 436 {
 437         return addr + (port * 64);
 438 }
 439
 440 static void vt6421_init_addrs(struct ata_port *ap)
 441 {
 442         void __iomem * const * iomap = ap->host->iomap;
 443         void __iomem *reg_addr = iomap[ap->port_no];
 444         void __iomem *bmdma_addr = iomap[4] + (ap->port_no * 8);
 445         struct ata_ioports *ioaddr = &ap->ioaddr;
 446
 447         ioaddr->cmd_addr = reg_addr;
 448         ioaddr->altstatus_addr =
 449         ioaddr->ctl_addr = (void __iomem *)
 450                 ((unsigned long)(reg_addr + 8) | ATA_PCI_CTL_OFS);
 451         ioaddr->bmdma_addr = bmdma_addr;
 452         ioaddr->scr_addr = vt6421_scr_addr(iomap[5], ap->port_no);
 453
 454         ata_sff_std_ports(ioaddr);
 455
 456         ata_port_pbar_desc(ap, ap->port_no, -1, "port");
 457         ata_port_pbar_desc(ap, 4, ap->port_no * 8, "bmdma");
 458 }
 459
 460 static int vt6420_prepare_host(struct pci_dev *pdev, struct ata_host **r_host)
 461 {
 462         const struct ata_port_info *ppi[] = { &vt6420_port_info, NULL };
 463         struct ata_host *host;
 464         int rc;
 465
 466         rc = ata_pci_bmdma_prepare_host(pdev, ppi, &host);
 467         if (rc)
 468                 return rc;
 469         *r_host = host;
 470
 471         rc = pcim_iomap_regions(pdev, 1 << 5, DRV_NAME);
 472         if (rc) {
 473                 dev_printk(KERN_ERR, &pdev->dev, "failed to iomap PCI BAR 5\n");
 474                 return rc;
 475         }
 476
 477         host->ports[0]->ioaddr.scr_addr = svia_scr_addr(host->iomap[5], 0);
 478         host->ports[1]->ioaddr.scr_addr = svia_scr_addr(host->iomap[5], 1);
 479
 480         return 0;
 481 }
 482
 483 static int vt6421_prepare_host(struct pci_dev *pdev, struct ata_host **r_host)
 484 {
 485         const struct ata_port_info *ppi[] =
 486                 { &vt6421_sport_info, &vt6421_sport_info, &vt6421_pport_info };
 487         struct ata_host *host;
 488         int i, rc;
 489
 490         *r_host = host = ata_host_alloc_pinfo(&pdev->dev, ppi, ARRAY_SIZE(ppi));
 491         if (!host) {
 492                 dev_printk(KERN_ERR, &pdev->dev, "failed to allocate host\n");
 493                 return -ENOMEM;
 494         }
 495
 496         rc = pcim_iomap_regions(pdev, 0x3f, DRV_NAME);
 497         if (rc) {
 498                 dev_printk(KERN_ERR, &pdev->dev, "failed to request/iomap "
 499                            "PCI BARs (errno=%d)\n", rc);
 500                 return rc;
 501         }
 502         host->iomap = pcim_iomap_table(pdev);
 503
 504         for (i = 0; i < host->n_ports; i++)
 505                 vt6421_init_addrs(host->ports[i]);
 506
 507         rc = pci_set_dma_mask(pdev, ATA_DMA_MASK);
 508         if (rc)
 509                 return rc;
 510         rc = pci_set_consistent_dma_mask(pdev, ATA_DMA_MASK);
 511         if (rc)
 512                 return rc;
 513
 514         return 0;
 515 }
 516
 517 static int vt8251_prepare_host(struct pci_dev *pdev, struct ata_host **r_host)
 518 {
 519         const struct ata_port_info *ppi[] = { &vt8251_port_info, NULL };
 520         struct ata_host *host;
 521         int i, rc;
 522
 523         rc = ata_pci_bmdma_prepare_host(pdev, ppi, &host);
 524         if (rc)
 525                 return rc;
 526         *r_host = host;
 527
 528         rc = pcim_iomap_regions(pdev, 1 << 5, DRV_NAME);
 529         if (rc) {
 530                 dev_printk(KERN_ERR, &pdev->dev, "failed to iomap PCI BAR 5\n");
 531                 return rc;
 532         }
 533
 534         /* 8251 hosts four sata ports as M/S of the two channels */
 535         for (i = 0; i < host->n_ports; i++)
 536                 ata_slave_link_init(host->ports[i]);
 537
 538         return 0;
 539 }
 540
 541 static void svia_configure(struct pci_dev *pdev, int board_id)
 542 {
 543         u8 tmp8;
 544
 545         pci_read_config_byte(pdev, PCI_INTERRUPT_LINE, &tmp8);
 546         dev_printk(KERN_INFO, &pdev->dev, "routed to hard irq line %d\n",
 547                (int) (tmp8 & 0xf0) == 0xf0 ? 0 : tmp8 & 0x0f);
 548
 549         /* make sure SATA channels are enabled */
 550         pci_read_config_byte(pdev, SATA_CHAN_ENAB, &tmp8);
 551         if ((tmp8 & ALL_PORTS) != ALL_PORTS) {
 552                 dev_printk(KERN_DEBUG, &pdev->dev,
 553                            "enabling SATA channels (0x%x)\n",
 554                            (int) tmp8);
 555                 tmp8 |= ALL_PORTS;
 556                 pci_write_config_byte(pdev, SATA_CHAN_ENAB, tmp8);
 557         }
 558
 559         /* make sure interrupts for each channel sent to us */
 560         pci_read_config_byte(pdev, SATA_INT_GATE, &tmp8);
 561         if ((tmp8 & ALL_PORTS) != ALL_PORTS) {
 562                 dev_printk(KERN_DEBUG, &pdev->dev,
 563                            "enabling SATA channel interrupts (0x%x)\n",
 564                            (int) tmp8);
 565                 tmp8 |= ALL_PORTS;
 566                 pci_write_config_byte(pdev, SATA_INT_GATE, tmp8);
 567         }
 568
 569         /* make sure native mode is enabled */
 570         pci_read_config_byte(pdev, SATA_NATIVE_MODE, &tmp8);
 571         if ((tmp8 & NATIVE_MODE_ALL) != NATIVE_MODE_ALL) {
 572                 dev_printk(KERN_DEBUG, &pdev->dev,
 573                            "enabling SATA channel native mode (0x%x)\n",
 574                            (int) tmp8);
 575                 tmp8 |= NATIVE_MODE_ALL;
 576                 pci_write_config_byte(pdev, SATA_NATIVE_MODE, tmp8);
 577         }
 578
 579         /*
 580          * vt6420/1 has problems talking to some drives.  The following
 581          * is the fix from Joseph Chan <JosephChan@via.com.tw>.
 582          *
 583          * When host issues HOLD, device may send up to 20DW of data
 584          * before acknowledging it with HOLDA and the host should be
 585          * able to buffer them in FIFO.  Unfortunately, some WD drives
 586          * send upto 40DW before acknowledging HOLD and, in the
 587          * default configuration, this ends up overflowing vt6421's
 588          * FIFO, making the controller abort the transaction with
 589          * R_ERR.
 590          *
 591          * Rx52[2] is the internal 128DW FIFO Flow control watermark
 592          * adjusting mechanism enable bit and the default value 0
 593          * means host will issue HOLD to device when the left FIFO
 594          * size goes below 32DW.  Setting it to 1 makes the watermark
 595          * 64DW.
 596          *
 597          * https://bugzilla.kernel.org/show_bug.cgi?id=15173
 598          * http://article.gmane.org/gmane.linux.ide/46352
 599          * http://thread.gmane.org/gmane.linux.kernel/1062139
 600          */
 601         if (board_id == vt6420 || board_id == vt6421) {
 602                 pci_read_config_byte(pdev, 0x52, &tmp8);
 603                 tmp8 |= 1 << 2;
 604                 pci_write_config_byte(pdev, 0x52, tmp8);
 605         }
 606 }
 607
 608 static int svia_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 609 {
 610         static int printed_version;
 611         unsigned int i;
 612         int rc;
 613         struct ata_host *host = NULL;
 614         int board_id = (int) ent->driver_data;
 615         const unsigned *bar_sizes;
 616
 617         if (!printed_version++)
 618                 dev_printk(KERN_DEBUG, &pdev->dev, "version " DRV_VERSION "\n");
 619
 620         rc = pcim_enable_device(pdev);
 621         if (rc)
 622                 return rc;
 623
 624         if (board_id == vt6421)
 625                 bar_sizes = &vt6421_bar_sizes[0];
 626         else
 627                 bar_sizes = &svia_bar_sizes[0];
 628
 629         for (i = 0; i < ARRAY_SIZE(svia_bar_sizes); i++)
 630                 if ((pci_resource_start(pdev, i) == 0) ||
 631                     (pci_resource_len(pdev, i) < bar_sizes[i])) {
 632                         dev_printk(KERN_ERR, &pdev->dev,
 633                                 "invalid PCI BAR %u (sz 0x%llx, val 0x%llx)\n",
 634                                 i,
 635                                 (unsigned long long)pci_resource_start(pdev, i),
 636                                 (unsigned long long)pci_resource_len(pdev, i));
 637                         return -ENODEV;
 638                 }
 639
 640         switch (board_id) {
 641         case vt6420:
 642                 rc = vt6420_prepare_host(pdev, &host);
 643                 break;
 644         case vt6421:
 645                 rc = vt6421_prepare_host(pdev, &host);
 646                 break;
 647         case vt8251:
 648                 rc = vt8251_prepare_host(pdev, &host);
 649                 break;
 650         default:
 651                 rc = -EINVAL;
 652         }
 653         if (rc)
 654                 return rc;
 655
 656         svia_configure(pdev, board_id);
 657
 658         pci_set_master(pdev);
 659         return ata_host_activate(host, pdev->irq, ata_bmdma_interrupt,
 660                                  IRQF_SHARED, &svia_sht);
 661 }
 662
 663 static int __init svia_init(void)
 664 {
 665         return pci_register_driver(&svia_pci_driver);
 666 }
 667
 668 static void __exit svia_exit(void)
 669 {
 670         pci_unregister_driver(&svia_pci_driver);
 671 }
 672
 673 module_init(svia_init);
 674 module_exit(svia_exit);