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