drivers/cdrom/gdrom.c

   1 /* GD ROM driver for the SEGA Dreamcast
   2  * copyright Adrian McMenamin, 2007
   3  * With thanks to Marcus Comstedt and Nathan Keynes
   4  * for work in reversing PIO and DMA
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  */
  21
  22 #include <linux/init.h>
  23 #include <linux/module.h>
  24 #include <linux/fs.h>
  25 #include <linux/kernel.h>
  26 #include <linux/list.h>
  27 #include <linux/slab.h>
  28 #include <linux/dma-mapping.h>
  29 #include <linux/cdrom.h>
  30 #include <linux/genhd.h>
  31 #include <linux/bio.h>
  32 #include <linux/blkdev.h>
  33 #include <linux/interrupt.h>
  34 #include <linux/device.h>
  35 #include <linux/wait.h>
  36 #include <linux/workqueue.h>
  37 #include <linux/platform_device.h>
  38 #include <scsi/scsi.h>
  39 #include <asm/io.h>
  40 #include <asm/dma.h>
  41 #include <asm/delay.h>
  42 #include <mach/dma.h>
  43 #include <mach/sysasic.h>
  44
  45 #define GDROM_DEV_NAME "gdrom"
  46 #define GD_SESSION_OFFSET 150
  47
  48 /* GD Rom commands */
  49 #define GDROM_COM_SOFTRESET 0x08
  50 #define GDROM_COM_EXECDIAG 0x90
  51 #define GDROM_COM_PACKET 0xA0
  52 #define GDROM_COM_IDDEV 0xA1
  53
  54 /* GD Rom registers */
  55 #define GDROM_BASE_REG                  0xA05F7000
  56 #define GDROM_ALTSTATUS_REG             (GDROM_BASE_REG + 0x18)
  57 #define GDROM_DATA_REG                  (GDROM_BASE_REG + 0x80)
  58 #define GDROM_ERROR_REG         (GDROM_BASE_REG + 0x84)
  59 #define GDROM_INTSEC_REG                (GDROM_BASE_REG + 0x88)
  60 #define GDROM_SECNUM_REG                (GDROM_BASE_REG + 0x8C)
  61 #define GDROM_BCL_REG                   (GDROM_BASE_REG + 0x90)
  62 #define GDROM_BCH_REG                   (GDROM_BASE_REG + 0x94)
  63 #define GDROM_DSEL_REG                  (GDROM_BASE_REG + 0x98)
  64 #define GDROM_STATUSCOMMAND_REG (GDROM_BASE_REG + 0x9C)
  65 #define GDROM_RESET_REG         (GDROM_BASE_REG + 0x4E4)
  66
  67 #define GDROM_DMA_STARTADDR_REG (GDROM_BASE_REG + 0x404)
  68 #define GDROM_DMA_LENGTH_REG            (GDROM_BASE_REG + 0x408)
  69 #define GDROM_DMA_DIRECTION_REG (GDROM_BASE_REG + 0x40C)
  70 #define GDROM_DMA_ENABLE_REG            (GDROM_BASE_REG + 0x414)
  71 #define GDROM_DMA_STATUS_REG            (GDROM_BASE_REG + 0x418)
  72 #define GDROM_DMA_WAIT_REG              (GDROM_BASE_REG + 0x4A0)
  73 #define GDROM_DMA_ACCESS_CTRL_REG       (GDROM_BASE_REG + 0x4B8)
  74
  75 #define GDROM_HARD_SECTOR       2048
  76 #define BLOCK_LAYER_SECTOR      512
  77 #define GD_TO_BLK               4
  78
  79 #define GDROM_DEFAULT_TIMEOUT   (HZ * 7)
  80
  81 static const struct {
  82         int sense_key;
  83         const char * const text;
  84 } sense_texts[] = {
  85         {NO_SENSE, "OK"},
  86         {RECOVERED_ERROR, "Recovered from error"},
  87         {NOT_READY, "Device not ready"},
  88         {MEDIUM_ERROR, "Disk not ready"},
  89         {HARDWARE_ERROR, "Hardware error"},
  90         {ILLEGAL_REQUEST, "Command has failed"},
  91         {UNIT_ATTENTION, "Device needs attention - disk may have been changed"},
  92         {DATA_PROTECT, "Data protection error"},
  93         {ABORTED_COMMAND, "Command aborted"},
  94 };
  95
  96 static struct platform_device *pd;
  97 static int gdrom_major;
  98 static DECLARE_WAIT_QUEUE_HEAD(command_queue);
  99 static DECLARE_WAIT_QUEUE_HEAD(request_queue);
 100
 101 static DEFINE_SPINLOCK(gdrom_lock);
 102 static void gdrom_readdisk_dma(struct work_struct *work);
 103 static DECLARE_WORK(work, gdrom_readdisk_dma);
 104 static LIST_HEAD(gdrom_deferred);
 105
 106 struct gdromtoc {
 107         unsigned int entry[99];
 108         unsigned int first, last;
 109         unsigned int leadout;
 110 };
 111
 112 static struct gdrom_unit {
 113         struct gendisk *disk;
 114         struct cdrom_device_info *cd_info;
 115         int status;
 116         int pending;
 117         int transfer;
 118         char disk_type;
 119         struct gdromtoc *toc;
 120         struct request_queue *gdrom_rq;
 121 } gd;
 122
 123 struct gdrom_id {
 124         char mid;
 125         char modid;
 126         char verid;
 127         char padA[13];
 128         char mname[16];
 129         char modname[16];
 130         char firmver[16];
 131         char padB[16];
 132 };
 133
 134 static int gdrom_getsense(short *bufstring);
 135 static int gdrom_packetcommand(struct cdrom_device_info *cd_info,
 136         struct packet_command *command);
 137 static int gdrom_hardreset(struct cdrom_device_info *cd_info);
 138
 139 static bool gdrom_is_busy(void)
 140 {
 141         return (ctrl_inb(GDROM_ALTSTATUS_REG) & 0x80) != 0;
 142 }
 143
 144 static bool gdrom_data_request(void)
 145 {
 146         return (ctrl_inb(GDROM_ALTSTATUS_REG) & 0x88) == 8;
 147 }
 148
 149 static bool gdrom_wait_clrbusy(void)
 150 {
 151         unsigned long timeout = jiffies + GDROM_DEFAULT_TIMEOUT;
 152         while ((ctrl_inb(GDROM_ALTSTATUS_REG) & 0x80) &&
 153                 (time_before(jiffies, timeout)))
 154                 cpu_relax();
 155         return time_before(jiffies, timeout + 1);
 156 }
 157
 158 static bool gdrom_wait_busy_sleeps(void)
 159 {
 160         unsigned long timeout;
 161         /* Wait to get busy first */
 162         timeout = jiffies + GDROM_DEFAULT_TIMEOUT;
 163         while (!gdrom_is_busy() && time_before(jiffies, timeout))
 164                 cpu_relax();
 165         /* Now wait for busy to clear */
 166         return gdrom_wait_clrbusy();
 167 }
 168
 169 static void gdrom_identifydevice(void *buf)
 170 {
 171         int c;
 172         short *data = buf;
 173         /* If the device won't clear it has probably
 174         * been hit by a serious failure - but we'll
 175         * try to return a sense key even so */
 176         if (!gdrom_wait_clrbusy()) {
 177                 gdrom_getsense(NULL);
 178                 return;
 179         }
 180         ctrl_outb(GDROM_COM_IDDEV, GDROM_STATUSCOMMAND_REG);
 181         if (!gdrom_wait_busy_sleeps()) {
 182                 gdrom_getsense(NULL);
 183                 return;
 184         }
 185         /* now read in the data */
 186         for (c = 0; c < 40; c++)
 187                 data[c] = ctrl_inw(GDROM_DATA_REG);
 188 }
 189
 190 static void gdrom_spicommand(void *spi_string, int buflen)
 191 {
 192         short *cmd = spi_string;
 193         unsigned long timeout;
 194
 195         /* ensure IRQ_WAIT is set */
 196         ctrl_outb(0x08, GDROM_ALTSTATUS_REG);
 197         /* specify how many bytes we expect back */
 198         ctrl_outb(buflen & 0xFF, GDROM_BCL_REG);
 199         ctrl_outb((buflen >> 8) & 0xFF, GDROM_BCH_REG);
 200         /* other parameters */
 201         ctrl_outb(0, GDROM_INTSEC_REG);
 202         ctrl_outb(0, GDROM_SECNUM_REG);
 203         ctrl_outb(0, GDROM_ERROR_REG);
 204         /* Wait until we can go */
 205         if (!gdrom_wait_clrbusy()) {
 206                 gdrom_getsense(NULL);
 207                 return;
 208         }
 209         timeout = jiffies + GDROM_DEFAULT_TIMEOUT;
 210         ctrl_outb(GDROM_COM_PACKET, GDROM_STATUSCOMMAND_REG);
 211         while (!gdrom_data_request() && time_before(jiffies, timeout))
 212                 cpu_relax();
 213         if (!time_before(jiffies, timeout + 1)) {
 214                 gdrom_getsense(NULL);
 215                 return;
 216         }
 217         outsw(PHYSADDR(GDROM_DATA_REG), cmd, 6);
 218 }
 219
 220
 221 /* gdrom_command_executediagnostic:
 222  * Used to probe for presence of working GDROM
 223  * Restarts GDROM device and then applies standard ATA 3
 224  * Execute Diagnostic Command: a return of '1' indicates device 0
 225  * present and device 1 absent
 226  */
 227 static char gdrom_execute_diagnostic(void)
 228 {
 229         gdrom_hardreset(gd.cd_info);
 230         if (!gdrom_wait_clrbusy())
 231                 return 0;
 232         ctrl_outb(GDROM_COM_EXECDIAG, GDROM_STATUSCOMMAND_REG);
 233         if (!gdrom_wait_busy_sleeps())
 234                 return 0;
 235         return ctrl_inb(GDROM_ERROR_REG);
 236 }
 237
 238 /*
 239  * Prepare disk command
 240  * byte 0 = 0x70
 241  * byte 1 = 0x1f
 242  */
 243 static int gdrom_preparedisk_cmd(void)
 244 {
 245         struct packet_command *spin_command;
 246         spin_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
 247         if (!spin_command)
 248                 return -ENOMEM;
 249         spin_command->cmd[0] = 0x70;
 250         spin_command->cmd[2] = 0x1f;
 251         spin_command->buflen = 0;
 252         gd.pending = 1;
 253         gdrom_packetcommand(gd.cd_info, spin_command);
 254         /* 60 second timeout */
 255         wait_event_interruptible_timeout(command_queue, gd.pending == 0,
 256                 GDROM_DEFAULT_TIMEOUT);
 257         gd.pending = 0;
 258         kfree(spin_command);
 259         if (gd.status & 0x01) {
 260                 /* log an error */
 261                 gdrom_getsense(NULL);
 262                 return -EIO;
 263         }
 264         return 0;
 265 }
 266
 267 /*
 268  * Read TOC command
 269  * byte 0 = 0x14
 270  * byte 1 = session
 271  * byte 3 = sizeof TOC >> 8  ie upper byte
 272  * byte 4 = sizeof TOC & 0xff ie lower byte
 273  */
 274 static int gdrom_readtoc_cmd(struct gdromtoc *toc, int session)
 275 {
 276         int tocsize;
 277         struct packet_command *toc_command;
 278         int err = 0;
 279
 280         toc_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
 281         if (!toc_command)
 282                 return -ENOMEM;
 283         tocsize = sizeof(struct gdromtoc);
 284         toc_command->cmd[0] = 0x14;
 285         toc_command->cmd[1] = session;
 286         toc_command->cmd[3] = tocsize >> 8;
 287         toc_command->cmd[4] = tocsize & 0xff;
 288         toc_command->buflen = tocsize;
 289         if (gd.pending) {
 290                 err = -EBUSY;
 291                 goto cleanup_readtoc_final;
 292         }
 293         gd.pending = 1;
 294         gdrom_packetcommand(gd.cd_info, toc_command);
 295         wait_event_interruptible_timeout(command_queue, gd.pending == 0,
 296                 GDROM_DEFAULT_TIMEOUT);
 297         if (gd.pending) {
 298                 err = -EINVAL;
 299                 goto cleanup_readtoc;
 300         }
 301         insw(PHYSADDR(GDROM_DATA_REG), toc, tocsize/2);
 302         if (gd.status & 0x01)
 303                 err = -EINVAL;
 304
 305 cleanup_readtoc:
 306         gd.pending = 0;
 307 cleanup_readtoc_final:
 308         kfree(toc_command);
 309         return err;
 310 }
 311
 312 /* TOC helpers */
 313 static int get_entry_lba(int track)
 314 {
 315         return (cpu_to_be32(track & 0xffffff00) - GD_SESSION_OFFSET);
 316 }
 317
 318 static int get_entry_q_ctrl(int track)
 319 {
 320         return (track & 0x000000f0) >> 4;
 321 }
 322
 323 static int get_entry_track(int track)
 324 {
 325         return (track & 0x0000ff00) >> 8;
 326 }
 327
 328 static int gdrom_get_last_session(struct cdrom_device_info *cd_info,
 329         struct cdrom_multisession *ms_info)
 330 {
 331         int fentry, lentry, track, data, tocuse, err;
 332         if (!gd.toc)
 333                 return -ENOMEM;
 334         tocuse = 1;
 335         /* Check if GD-ROM */
 336         err = gdrom_readtoc_cmd(gd.toc, 1);
 337         /* Not a GD-ROM so check if standard CD-ROM */
 338         if (err) {
 339                 tocuse = 0;
 340                 err = gdrom_readtoc_cmd(gd.toc, 0);
 341                 if (err) {
 342                         printk(KERN_INFO "GDROM: Could not get CD "
 343                                 "table of contents\n");
 344                         return -ENXIO;
 345                 }
 346         }
 347
 348         fentry = get_entry_track(gd.toc->first);
 349         lentry = get_entry_track(gd.toc->last);
 350         /* Find the first data track */
 351         track = get_entry_track(gd.toc->last);
 352         do {
 353                 data = gd.toc->entry[track - 1];
 354                 if (get_entry_q_ctrl(data))
 355                         break;  /* ie a real data track */
 356                 track--;
 357         } while (track >= fentry);
 358
 359         if ((track > 100) || (track < get_entry_track(gd.toc->first))) {
 360                 printk(KERN_INFO "GDROM: No data on the last "
 361                         "session of the CD\n");
 362                 gdrom_getsense(NULL);
 363                 return -ENXIO;
 364         }
 365
 366         ms_info->addr_format = CDROM_LBA;
 367         ms_info->addr.lba = get_entry_lba(data);
 368         ms_info->xa_flag = 1;
 369         return 0;
 370 }
 371
 372 static int gdrom_open(struct cdrom_device_info *cd_info, int purpose)
 373 {
 374         /* spin up the disk */
 375         return gdrom_preparedisk_cmd();
 376 }
 377
 378 /* this function is required even if empty */
 379 static void gdrom_release(struct cdrom_device_info *cd_info)
 380 {
 381 }
 382
 383 static int gdrom_drivestatus(struct cdrom_device_info *cd_info, int ignore)
 384 {
 385         /* read the sense key */
 386         char sense = ctrl_inb(GDROM_ERROR_REG);
 387         sense &= 0xF0;
 388         if (sense == 0)
 389                 return CDS_DISC_OK;
 390         if (sense == 0x20)
 391                 return CDS_DRIVE_NOT_READY;
 392         /* default */
 393         return CDS_NO_INFO;
 394 }
 395
 396 static int gdrom_mediachanged(struct cdrom_device_info *cd_info, int ignore)
 397 {
 398         /* check the sense key */
 399         return (ctrl_inb(GDROM_ERROR_REG) & 0xF0) == 0x60;
 400 }
 401
 402 /* reset the G1 bus */
 403 static int gdrom_hardreset(struct cdrom_device_info *cd_info)
 404 {
 405         int count;
 406         ctrl_outl(0x1fffff, GDROM_RESET_REG);
 407         for (count = 0xa0000000; count < 0xa0200000; count += 4)
 408                 ctrl_inl(count);
 409         return 0;
 410 }
 411
 412 /* keep the function looking like the universal
 413  * CD Rom specification  - returning int */
 414 static int gdrom_packetcommand(struct cdrom_device_info *cd_info,
 415         struct packet_command *command)
 416 {
 417         gdrom_spicommand(&command->cmd, command->buflen);
 418         return 0;
 419 }
 420
 421 /* Get Sense SPI command
 422  * From Marcus Comstedt
 423  * cmd = 0x13
 424  * cmd + 4 = length of returned buffer
 425  * Returns 5 16 bit words
 426  */
 427 static int gdrom_getsense(short *bufstring)
 428 {
 429         struct packet_command *sense_command;
 430         short sense[5];
 431         int sense_key;
 432         int err = -EIO;
 433
 434         sense_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
 435         if (!sense_command)
 436                 return -ENOMEM;
 437         sense_command->cmd[0] = 0x13;
 438         sense_command->cmd[4] = 10;
 439         sense_command->buflen = 10;
 440         /* even if something is pending try to get
 441         * the sense key if possible */
 442         if (gd.pending && !gdrom_wait_clrbusy()) {
 443                 err = -EBUSY;
 444                 goto cleanup_sense_final;
 445         }
 446         gd.pending = 1;
 447         gdrom_packetcommand(gd.cd_info, sense_command);
 448         wait_event_interruptible_timeout(command_queue, gd.pending == 0,
 449                 GDROM_DEFAULT_TIMEOUT);
 450         if (gd.pending)
 451                 goto cleanup_sense;
 452         insw(PHYSADDR(GDROM_DATA_REG), &sense, sense_command->buflen/2);
 453         if (sense[1] & 40) {
 454                 printk(KERN_INFO "GDROM: Drive not ready - command aborted\n");
 455                 goto cleanup_sense;
 456         }
 457         sense_key = sense[1] & 0x0F;
 458         if (sense_key < ARRAY_SIZE(sense_texts))
 459                 printk(KERN_INFO "GDROM: %s\n", sense_texts[sense_key].text);
 460         else
 461                 printk(KERN_ERR "GDROM: Unknown sense key: %d\n", sense_key);
 462         if (bufstring) /* return addional sense data */
 463                 memcpy(bufstring, &sense[4], 2);
 464         if (sense_key < 2)
 465                 err = 0;
 466
 467 cleanup_sense:
 468         gd.pending = 0;
 469 cleanup_sense_final:
 470         kfree(sense_command);
 471         return err;
 472 }
 473
 474 static int gdrom_audio_ioctl(struct cdrom_device_info *cdi, unsigned int cmd,
 475                              void *arg)
 476 {
 477         return -EINVAL;
 478 }
 479
 480 static struct cdrom_device_ops gdrom_ops = {
 481         .open                   = gdrom_open,
 482         .release                = gdrom_release,
 483         .drive_status           = gdrom_drivestatus,
 484         .media_changed          = gdrom_mediachanged,
 485         .get_last_session       = gdrom_get_last_session,
 486         .reset                  = gdrom_hardreset,
 487         .audio_ioctl            = gdrom_audio_ioctl,
 488         .capability             = CDC_MULTI_SESSION | CDC_MEDIA_CHANGED |
 489                                   CDC_RESET | CDC_DRIVE_STATUS | CDC_CD_R,
 490         .n_minors               = 1,
 491 };
 492
 493 static int gdrom_bdops_open(struct block_device *bdev, fmode_t mode)
 494 {
 495         return cdrom_open(gd.cd_info, bdev, mode);
 496 }
 497
 498 static int gdrom_bdops_release(struct gendisk *disk, fmode_t mode)
 499 {
 500         cdrom_release(gd.cd_info, mode);
 501         return 0;
 502 }
 503
 504 static int gdrom_bdops_mediachanged(struct gendisk *disk)
 505 {
 506         return cdrom_media_changed(gd.cd_info);
 507 }
 508
 509 static int gdrom_bdops_ioctl(struct block_device *bdev, fmode_t mode,
 510         unsigned cmd, unsigned long arg)
 511 {
 512         return cdrom_ioctl(gd.cd_info, bdev, mode, cmd, arg);
 513 }
 514
 515 static struct block_device_operations gdrom_bdops = {
 516         .owner                  = THIS_MODULE,
 517         .open                   = gdrom_bdops_open,
 518         .release                = gdrom_bdops_release,
 519         .media_changed          = gdrom_bdops_mediachanged,
 520         .locked_ioctl           = gdrom_bdops_ioctl,
 521 };
 522
 523 static irqreturn_t gdrom_command_interrupt(int irq, void *dev_id)
 524 {
 525         gd.status = ctrl_inb(GDROM_STATUSCOMMAND_REG);
 526         if (gd.pending != 1)
 527                 return IRQ_HANDLED;
 528         gd.pending = 0;
 529         wake_up_interruptible(&command_queue);
 530         return IRQ_HANDLED;
 531 }
 532
 533 static irqreturn_t gdrom_dma_interrupt(int irq, void *dev_id)
 534 {
 535         gd.status = ctrl_inb(GDROM_STATUSCOMMAND_REG);
 536         if (gd.transfer != 1)
 537                 return IRQ_HANDLED;
 538         gd.transfer = 0;
 539         wake_up_interruptible(&request_queue);
 540         return IRQ_HANDLED;
 541 }
 542
 543 static int __devinit gdrom_set_interrupt_handlers(void)
 544 {
 545         int err;
 546
 547         err = request_irq(HW_EVENT_GDROM_CMD, gdrom_command_interrupt,
 548                 IRQF_DISABLED, "gdrom_command", &gd);
 549         if (err)
 550                 return err;
 551         err = request_irq(HW_EVENT_GDROM_DMA, gdrom_dma_interrupt,
 552                 IRQF_DISABLED, "gdrom_dma", &gd);
 553         if (err)
 554                 free_irq(HW_EVENT_GDROM_CMD, &gd);
 555         return err;
 556 }
 557
 558 /* Implement DMA read using SPI command
 559  * 0 -> 0x30
 560  * 1 -> mode
 561  * 2 -> block >> 16
 562  * 3 -> block >> 8
 563  * 4 -> block
 564  * 8 -> sectors >> 16
 565  * 9 -> sectors >> 8
 566  * 10 -> sectors
 567  */
 568 static void gdrom_readdisk_dma(struct work_struct *work)
 569 {
 570         int err, block, block_cnt;
 571         struct packet_command *read_command;
 572         struct list_head *elem, *next;
 573         struct request *req;
 574         unsigned long timeout;
 575
 576         if (list_empty(&gdrom_deferred))
 577                 return;
 578         read_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
 579         if (!read_command)
 580                 return; /* get more memory later? */
 581         read_command->cmd[0] = 0x30;
 582         read_command->cmd[1] = 0x20;
 583         spin_lock(&gdrom_lock);
 584         list_for_each_safe(elem, next, &gdrom_deferred) {
 585                 req = list_entry(elem, struct request, queuelist);
 586                 spin_unlock(&gdrom_lock);
 587                 block = req->sector/GD_TO_BLK + GD_SESSION_OFFSET;
 588                 block_cnt = req->nr_sectors/GD_TO_BLK;
 589                 ctrl_outl(PHYSADDR(req->buffer), GDROM_DMA_STARTADDR_REG);
 590                 ctrl_outl(block_cnt * GDROM_HARD_SECTOR, GDROM_DMA_LENGTH_REG);
 591                 ctrl_outl(1, GDROM_DMA_DIRECTION_REG);
 592                 ctrl_outl(1, GDROM_DMA_ENABLE_REG);
 593                 read_command->cmd[2] = (block >> 16) & 0xFF;
 594                 read_command->cmd[3] = (block >> 8) & 0xFF;
 595                 read_command->cmd[4] = block & 0xFF;
 596                 read_command->cmd[8] = (block_cnt >> 16) & 0xFF;
 597                 read_command->cmd[9] = (block_cnt >> 8) & 0xFF;
 598                 read_command->cmd[10] = block_cnt & 0xFF;
 599                 /* set for DMA */
 600                 ctrl_outb(1, GDROM_ERROR_REG);
 601                 /* other registers */
 602                 ctrl_outb(0, GDROM_SECNUM_REG);
 603                 ctrl_outb(0, GDROM_BCL_REG);
 604                 ctrl_outb(0, GDROM_BCH_REG);
 605                 ctrl_outb(0, GDROM_DSEL_REG);
 606                 ctrl_outb(0, GDROM_INTSEC_REG);
 607                 /* Wait for registers to reset after any previous activity */
 608                 timeout = jiffies + HZ / 2;
 609                 while (gdrom_is_busy() && time_before(jiffies, timeout))
 610                         cpu_relax();
 611                 ctrl_outb(GDROM_COM_PACKET, GDROM_STATUSCOMMAND_REG);
 612                 timeout = jiffies + HZ / 2;
 613                 /* Wait for packet command to finish */
 614                 while (gdrom_is_busy() && time_before(jiffies, timeout))
 615                         cpu_relax();
 616                 gd.pending = 1;
 617                 gd.transfer = 1;
 618                 outsw(PHYSADDR(GDROM_DATA_REG), &read_command->cmd, 6);
 619                 timeout = jiffies + HZ / 2;
 620                 /* Wait for any pending DMA to finish */
 621                 while (ctrl_inb(GDROM_DMA_STATUS_REG) &&
 622                         time_before(jiffies, timeout))
 623                         cpu_relax();
 624                 /* start transfer */
 625                 ctrl_outb(1, GDROM_DMA_STATUS_REG);
 626                 wait_event_interruptible_timeout(request_queue,
 627                         gd.transfer == 0, GDROM_DEFAULT_TIMEOUT);
 628                 err = gd.transfer ? -EIO : 0;
 629                 gd.transfer = 0;
 630                 gd.pending = 0;
 631                 /* now seek to take the request spinlock
 632                 * before handling ending the request */
 633                 spin_lock(&gdrom_lock);
 634                 list_del_init(&req->queuelist);
 635                 __blk_end_request(req, err, blk_rq_bytes(req));
 636         }
 637         spin_unlock(&gdrom_lock);
 638         kfree(read_command);
 639 }
 640
 641 static void gdrom_request_handler_dma(struct request *req)
 642 {
 643         /* dequeue, add to list of deferred work
 644         * and then schedule workqueue */
 645         blkdev_dequeue_request(req);
 646         list_add_tail(&req->queuelist, &gdrom_deferred);
 647         schedule_work(&work);
 648 }
 649
 650 static void gdrom_request(struct request_queue *rq)
 651 {
 652         struct request *req;
 653
 654         while ((req = elv_next_request(rq)) != NULL) {
 655                 if (!blk_fs_request(req)) {
 656                         printk(KERN_DEBUG "GDROM: Non-fs request ignored\n");
 657                         end_request(req, 0);
 658                 }
 659                 if (rq_data_dir(req) != READ) {
 660                         printk(KERN_NOTICE "GDROM: Read only device -");
 661                         printk(" write request ignored\n");
 662                         end_request(req, 0);
 663                 }
 664                 if (req->nr_sectors)
 665                         gdrom_request_handler_dma(req);
 666                 else
 667                         end_request(req, 0);
 668         }
 669 }
 670
 671 /* Print string identifying GD ROM device */
 672 static int __devinit gdrom_outputversion(void)
 673 {
 674         struct gdrom_id *id;
 675         char *model_name, *manuf_name, *firmw_ver;
 676         int err = -ENOMEM;
 677
 678         /* query device ID */
 679         id = kzalloc(sizeof(struct gdrom_id), GFP_KERNEL);
 680         if (!id)
 681                 return err;
 682         gdrom_identifydevice(id);
 683         model_name = kstrndup(id->modname, 16, GFP_KERNEL);
 684         if (!model_name)
 685                 goto free_id;
 686         manuf_name = kstrndup(id->mname, 16, GFP_KERNEL);
 687         if (!manuf_name)
 688                 goto free_model_name;
 689         firmw_ver = kstrndup(id->firmver, 16, GFP_KERNEL);
 690         if (!firmw_ver)
 691                 goto free_manuf_name;
 692         printk(KERN_INFO "GDROM: %s from %s with firmware %s\n",
 693                 model_name, manuf_name, firmw_ver);
 694         err = 0;
 695         kfree(firmw_ver);
 696 free_manuf_name:
 697         kfree(manuf_name);
 698 free_model_name:
 699         kfree(model_name);
 700 free_id:
 701         kfree(id);
 702         return err;
 703 }
 704
 705 /* set the default mode for DMA transfer */
 706 static int __devinit gdrom_init_dma_mode(void)
 707 {
 708         ctrl_outb(0x13, GDROM_ERROR_REG);
 709         ctrl_outb(0x22, GDROM_INTSEC_REG);
 710         if (!gdrom_wait_clrbusy())
 711                 return -EBUSY;
 712         ctrl_outb(0xEF, GDROM_STATUSCOMMAND_REG);
 713         if (!gdrom_wait_busy_sleeps())
 714                 return -EBUSY;
 715         /* Memory protection setting for GDROM DMA
 716         * Bits 31 - 16 security: 0x8843
 717         * Bits 15 and 7 reserved (0)
 718         * Bits 14 - 8 start of transfer range in 1 MB blocks OR'ed with 0x80
 719         * Bits 6 - 0 end of transfer range in 1 MB blocks OR'ed with 0x80
 720         * (0x40 | 0x80) = start range at 0x0C000000
 721         * (0x7F | 0x80) = end range at 0x0FFFFFFF */
 722         ctrl_outl(0x8843407F, GDROM_DMA_ACCESS_CTRL_REG);
 723         ctrl_outl(9, GDROM_DMA_WAIT_REG); /* DMA word setting */
 724         return 0;
 725 }
 726
 727 static void __devinit probe_gdrom_setupcd(void)
 728 {
 729         gd.cd_info->ops = &gdrom_ops;
 730         gd.cd_info->capacity = 1;
 731         strcpy(gd.cd_info->name, GDROM_DEV_NAME);
 732         gd.cd_info->mask = CDC_CLOSE_TRAY|CDC_OPEN_TRAY|CDC_LOCK|
 733                 CDC_SELECT_DISC;
 734 }
 735
 736 static void __devinit probe_gdrom_setupdisk(void)
 737 {
 738         gd.disk->major = gdrom_major;
 739         gd.disk->first_minor = 1;
 740         gd.disk->minors = 1;
 741         strcpy(gd.disk->disk_name, GDROM_DEV_NAME);
 742 }
 743
 744 static int __devinit probe_gdrom_setupqueue(void)
 745 {
 746         blk_queue_hardsect_size(gd.gdrom_rq, GDROM_HARD_SECTOR);
 747         /* using DMA so memory will need to be contiguous */
 748         blk_queue_max_hw_segments(gd.gdrom_rq, 1);
 749         /* set a large max size to get most from DMA */
 750         blk_queue_max_segment_size(gd.gdrom_rq, 0x40000);
 751         gd.disk->queue = gd.gdrom_rq;
 752         return gdrom_init_dma_mode();
 753 }
 754
 755 /*
 756  * register this as a block device and as compliant with the
 757  * universal CD Rom driver interface
 758  */
 759 static int __devinit probe_gdrom(struct platform_device *devptr)
 760 {
 761         int err;
 762         /* Start the device */
 763         if (gdrom_execute_diagnostic() != 1) {
 764                 printk(KERN_WARNING "GDROM: ATA Probe for GDROM failed.\n");
 765                 return -ENODEV;
 766         }
 767         /* Print out firmware ID */
 768         if (gdrom_outputversion())
 769                 return -ENOMEM;
 770         /* Register GDROM */
 771         gdrom_major = register_blkdev(0, GDROM_DEV_NAME);
 772         if (gdrom_major <= 0)
 773                 return gdrom_major;
 774         printk(KERN_INFO "GDROM: Registered with major number %d\n",
 775                 gdrom_major);
 776         /* Specify basic properties of drive */
 777         gd.cd_info = kzalloc(sizeof(struct cdrom_device_info), GFP_KERNEL);
 778         if (!gd.cd_info) {
 779                 err = -ENOMEM;
 780                 goto probe_fail_no_mem;
 781         }
 782         probe_gdrom_setupcd();
 783         gd.disk = alloc_disk(1);
 784         if (!gd.disk) {
 785                 err = -ENODEV;
 786                 goto probe_fail_no_disk;
 787         }
 788         probe_gdrom_setupdisk();
 789         if (register_cdrom(gd.cd_info)) {
 790                 err = -ENODEV;
 791                 goto probe_fail_cdrom_register;
 792         }
 793         gd.disk->fops = &gdrom_bdops;
 794         /* latch on to the interrupt */
 795         err = gdrom_set_interrupt_handlers();
 796         if (err)
 797                 goto probe_fail_cmdirq_register;
 798         gd.gdrom_rq = blk_init_queue(gdrom_request, &gdrom_lock);
 799         if (!gd.gdrom_rq)
 800                 goto probe_fail_requestq;
 801
 802         err = probe_gdrom_setupqueue();
 803         if (err)
 804                 goto probe_fail_toc;
 805
 806         gd.toc = kzalloc(sizeof(struct gdromtoc), GFP_KERNEL);
 807         if (!gd.toc)
 808                 goto probe_fail_toc;
 809         add_disk(gd.disk);
 810         return 0;
 811
 812 probe_fail_toc:
 813         blk_cleanup_queue(gd.gdrom_rq);
 814 probe_fail_requestq:
 815         free_irq(HW_EVENT_GDROM_DMA, &gd);
 816         free_irq(HW_EVENT_GDROM_CMD, &gd);
 817 probe_fail_cmdirq_register:
 818 probe_fail_cdrom_register:
 819         del_gendisk(gd.disk);
 820 probe_fail_no_disk:
 821         kfree(gd.cd_info);
 822         unregister_blkdev(gdrom_major, GDROM_DEV_NAME);
 823         gdrom_major = 0;
 824 probe_fail_no_mem:
 825         printk(KERN_WARNING "GDROM: Probe failed - error is 0x%X\n", err);
 826         return err;
 827 }
 828
 829 static int __devexit remove_gdrom(struct platform_device *devptr)
 830 {
 831         flush_scheduled_work();
 832         blk_cleanup_queue(gd.gdrom_rq);
 833         free_irq(HW_EVENT_GDROM_CMD, &gd);
 834         free_irq(HW_EVENT_GDROM_DMA, &gd);
 835         del_gendisk(gd.disk);
 836         if (gdrom_major)
 837                 unregister_blkdev(gdrom_major, GDROM_DEV_NAME);
 838         unregister_cdrom(gd.cd_info);
 839
 840         return 0;
 841 }
 842
 843 static struct platform_driver gdrom_driver = {
 844         .probe = probe_gdrom,
 845         .remove = __devexit_p(remove_gdrom),
 846         .driver = {
 847                         .name = GDROM_DEV_NAME,
 848         },
 849 };
 850
 851 static int __init init_gdrom(void)
 852 {
 853         int rc;
 854         gd.toc = NULL;
 855         rc = platform_driver_register(&gdrom_driver);
 856         if (rc)
 857                 return rc;
 858         pd = platform_device_register_simple(GDROM_DEV_NAME, -1, NULL, 0);
 859         if (IS_ERR(pd)) {
 860                 platform_driver_unregister(&gdrom_driver);
 861                 return PTR_ERR(pd);
 862         }
 863         return 0;
 864 }
 865
 866 static void __exit exit_gdrom(void)
 867 {
 868         platform_device_unregister(pd);
 869         platform_driver_unregister(&gdrom_driver);
 870         kfree(gd.toc);
 871 }
 872
 873 module_init(init_gdrom);
 874 module_exit(exit_gdrom);
 875 MODULE_AUTHOR("Adrian McMenamin <adrian@mcmen.demon.co.uk>");
 876 MODULE_DESCRIPTION("SEGA Dreamcast GD-ROM Driver");
 877 MODULE_LICENSE("GPL");