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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  23
  24 #include <linux/init.h>
  25 #include <linux/module.h>
  26 #include <linux/fs.h>
  27 #include <linux/kernel.h>
  28 #include <linux/list.h>
  29 #include <linux/slab.h>
  30 #include <linux/dma-mapping.h>
  31 #include <linux/cdrom.h>
  32 #include <linux/genhd.h>
  33 #include <linux/bio.h>
  34 #include <linux/blkdev.h>
  35 #include <linux/interrupt.h>
  36 #include <linux/device.h>
  37 #include <linux/mutex.h>
  38 #include <linux/wait.h>
  39 #include <linux/workqueue.h>
  40 #include <linux/platform_device.h>
  41 #include <scsi/scsi.h>
  42 #include <asm/io.h>
  43 #include <asm/dma.h>
  44 #include <asm/delay.h>
  45 #include <mach/dma.h>
  46 #include <mach/sysasic.h>
  47
  48 #define GDROM_DEV_NAME "gdrom"
  49 #define GD_SESSION_OFFSET 150
  50
  51 /* GD Rom commands */
  52 #define GDROM_COM_SOFTRESET 0x08
  53 #define GDROM_COM_EXECDIAG 0x90
  54 #define GDROM_COM_PACKET 0xA0
  55 #define GDROM_COM_IDDEV 0xA1
  56
  57 /* GD Rom registers */
  58 #define GDROM_BASE_REG                  0xA05F7000
  59 #define GDROM_ALTSTATUS_REG             (GDROM_BASE_REG + 0x18)
  60 #define GDROM_DATA_REG                  (GDROM_BASE_REG + 0x80)
  61 #define GDROM_ERROR_REG         (GDROM_BASE_REG + 0x84)
  62 #define GDROM_INTSEC_REG                (GDROM_BASE_REG + 0x88)
  63 #define GDROM_SECNUM_REG                (GDROM_BASE_REG + 0x8C)
  64 #define GDROM_BCL_REG                   (GDROM_BASE_REG + 0x90)
  65 #define GDROM_BCH_REG                   (GDROM_BASE_REG + 0x94)
  66 #define GDROM_DSEL_REG                  (GDROM_BASE_REG + 0x98)
  67 #define GDROM_STATUSCOMMAND_REG (GDROM_BASE_REG + 0x9C)
  68 #define GDROM_RESET_REG         (GDROM_BASE_REG + 0x4E4)
  69
  70 #define GDROM_DMA_STARTADDR_REG (GDROM_BASE_REG + 0x404)
  71 #define GDROM_DMA_LENGTH_REG            (GDROM_BASE_REG + 0x408)
  72 #define GDROM_DMA_DIRECTION_REG (GDROM_BASE_REG + 0x40C)
  73 #define GDROM_DMA_ENABLE_REG            (GDROM_BASE_REG + 0x414)
  74 #define GDROM_DMA_STATUS_REG            (GDROM_BASE_REG + 0x418)
  75 #define GDROM_DMA_WAIT_REG              (GDROM_BASE_REG + 0x4A0)
  76 #define GDROM_DMA_ACCESS_CTRL_REG       (GDROM_BASE_REG + 0x4B8)
  77
  78 #define GDROM_HARD_SECTOR       2048
  79 #define BLOCK_LAYER_SECTOR      512
  80 #define GD_TO_BLK               4
  81
  82 #define GDROM_DEFAULT_TIMEOUT   (HZ * 7)
  83
  84 static DEFINE_MUTEX(gdrom_mutex);
  85 static const struct {
  86         int sense_key;
  87         const char * const text;
  88 } sense_texts[] = {
  89         {NO_SENSE, "OK"},
  90         {RECOVERED_ERROR, "Recovered from error"},
  91         {NOT_READY, "Device not ready"},
  92         {MEDIUM_ERROR, "Disk not ready"},
  93         {HARDWARE_ERROR, "Hardware error"},
  94         {ILLEGAL_REQUEST, "Command has failed"},
  95         {UNIT_ATTENTION, "Device needs attention - disk may have been changed"},
  96         {DATA_PROTECT, "Data protection error"},
  97         {ABORTED_COMMAND, "Command aborted"},
  98 };
  99
 100 static struct platform_device *pd;
 101 static int gdrom_major;
 102 static DECLARE_WAIT_QUEUE_HEAD(command_queue);
 103 static DECLARE_WAIT_QUEUE_HEAD(request_queue);
 104
 105 static DEFINE_SPINLOCK(gdrom_lock);
 106 static void gdrom_readdisk_dma(struct work_struct *work);
 107 static DECLARE_WORK(work, gdrom_readdisk_dma);
 108 static LIST_HEAD(gdrom_deferred);
 109
 110 struct gdromtoc {
 111         unsigned int entry[99];
 112         unsigned int first, last;
 113         unsigned int leadout;
 114 };
 115
 116 static struct gdrom_unit {
 117         struct gendisk *disk;
 118         struct cdrom_device_info *cd_info;
 119         int status;
 120         int pending;
 121         int transfer;
 122         char disk_type;
 123         struct gdromtoc *toc;
 124         struct request_queue *gdrom_rq;
 125 } gd;
 126
 127 struct gdrom_id {
 128         char mid;
 129         char modid;
 130         char verid;
 131         char padA[13];
 132         char mname[16];
 133         char modname[16];
 134         char firmver[16];
 135         char padB[16];
 136 };
 137
 138 static int gdrom_getsense(short *bufstring);
 139 static int gdrom_packetcommand(struct cdrom_device_info *cd_info,
 140         struct packet_command *command);
 141 static int gdrom_hardreset(struct cdrom_device_info *cd_info);
 142
 143 static bool gdrom_is_busy(void)
 144 {
 145         return (ctrl_inb(GDROM_ALTSTATUS_REG) & 0x80) != 0;
 146 }
 147
 148 static bool gdrom_data_request(void)
 149 {
 150         return (ctrl_inb(GDROM_ALTSTATUS_REG) & 0x88) == 8;
 151 }
 152
 153 static bool gdrom_wait_clrbusy(void)
 154 {
 155         unsigned long timeout = jiffies + GDROM_DEFAULT_TIMEOUT;
 156         while ((ctrl_inb(GDROM_ALTSTATUS_REG) & 0x80) &&
 157                 (time_before(jiffies, timeout)))
 158                 cpu_relax();
 159         return time_before(jiffies, timeout + 1);
 160 }
 161
 162 static bool gdrom_wait_busy_sleeps(void)
 163 {
 164         unsigned long timeout;
 165         /* Wait to get busy first */
 166         timeout = jiffies + GDROM_DEFAULT_TIMEOUT;
 167         while (!gdrom_is_busy() && time_before(jiffies, timeout))
 168                 cpu_relax();
 169         /* Now wait for busy to clear */
 170         return gdrom_wait_clrbusy();
 171 }
 172
 173 static void gdrom_identifydevice(void *buf)
 174 {
 175         int c;
 176         short *data = buf;
 177         /* If the device won't clear it has probably
 178         * been hit by a serious failure - but we'll
 179         * try to return a sense key even so */
 180         if (!gdrom_wait_clrbusy()) {
 181                 gdrom_getsense(NULL);
 182                 return;
 183         }
 184         ctrl_outb(GDROM_COM_IDDEV, GDROM_STATUSCOMMAND_REG);
 185         if (!gdrom_wait_busy_sleeps()) {
 186                 gdrom_getsense(NULL);
 187                 return;
 188         }
 189         /* now read in the data */
 190         for (c = 0; c < 40; c++)
 191                 data[c] = ctrl_inw(GDROM_DATA_REG);
 192 }
 193
 194 static void gdrom_spicommand(void *spi_string, int buflen)
 195 {
 196         short *cmd = spi_string;
 197         unsigned long timeout;
 198
 199         /* ensure IRQ_WAIT is set */
 200         ctrl_outb(0x08, GDROM_ALTSTATUS_REG);
 201         /* specify how many bytes we expect back */
 202         ctrl_outb(buflen & 0xFF, GDROM_BCL_REG);
 203         ctrl_outb((buflen >> 8) & 0xFF, GDROM_BCH_REG);
 204         /* other parameters */
 205         ctrl_outb(0, GDROM_INTSEC_REG);
 206         ctrl_outb(0, GDROM_SECNUM_REG);
 207         ctrl_outb(0, GDROM_ERROR_REG);
 208         /* Wait until we can go */
 209         if (!gdrom_wait_clrbusy()) {
 210                 gdrom_getsense(NULL);
 211                 return;
 212         }
 213         timeout = jiffies + GDROM_DEFAULT_TIMEOUT;
 214         ctrl_outb(GDROM_COM_PACKET, GDROM_STATUSCOMMAND_REG);
 215         while (!gdrom_data_request() && time_before(jiffies, timeout))
 216                 cpu_relax();
 217         if (!time_before(jiffies, timeout + 1)) {
 218                 gdrom_getsense(NULL);
 219                 return;
 220         }
 221         outsw(GDROM_DATA_REG, cmd, 6);
 222 }
 223
 224
 225 /* gdrom_command_executediagnostic:
 226  * Used to probe for presence of working GDROM
 227  * Restarts GDROM device and then applies standard ATA 3
 228  * Execute Diagnostic Command: a return of '1' indicates device 0
 229  * present and device 1 absent
 230  */
 231 static char gdrom_execute_diagnostic(void)
 232 {
 233         gdrom_hardreset(gd.cd_info);
 234         if (!gdrom_wait_clrbusy())
 235                 return 0;
 236         ctrl_outb(GDROM_COM_EXECDIAG, GDROM_STATUSCOMMAND_REG);
 237         if (!gdrom_wait_busy_sleeps())
 238                 return 0;
 239         return ctrl_inb(GDROM_ERROR_REG);
 240 }
 241
 242 /*
 243  * Prepare disk command
 244  * byte 0 = 0x70
 245  * byte 1 = 0x1f
 246  */
 247 static int gdrom_preparedisk_cmd(void)
 248 {
 249         struct packet_command *spin_command;
 250         spin_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
 251         if (!spin_command)
 252                 return -ENOMEM;
 253         spin_command->cmd[0] = 0x70;
 254         spin_command->cmd[2] = 0x1f;
 255         spin_command->buflen = 0;
 256         gd.pending = 1;
 257         gdrom_packetcommand(gd.cd_info, spin_command);
 258         /* 60 second timeout */
 259         wait_event_interruptible_timeout(command_queue, gd.pending == 0,
 260                 GDROM_DEFAULT_TIMEOUT);
 261         gd.pending = 0;
 262         kfree(spin_command);
 263         if (gd.status & 0x01) {
 264                 /* log an error */
 265                 gdrom_getsense(NULL);
 266                 return -EIO;
 267         }
 268         return 0;
 269 }
 270
 271 /*
 272  * Read TOC command
 273  * byte 0 = 0x14
 274  * byte 1 = session
 275  * byte 3 = sizeof TOC >> 8  ie upper byte
 276  * byte 4 = sizeof TOC & 0xff ie lower byte
 277  */
 278 static int gdrom_readtoc_cmd(struct gdromtoc *toc, int session)
 279 {
 280         int tocsize;
 281         struct packet_command *toc_command;
 282         int err = 0;
 283
 284         toc_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
 285         if (!toc_command)
 286                 return -ENOMEM;
 287         tocsize = sizeof(struct gdromtoc);
 288         toc_command->cmd[0] = 0x14;
 289         toc_command->cmd[1] = session;
 290         toc_command->cmd[3] = tocsize >> 8;
 291         toc_command->cmd[4] = tocsize & 0xff;
 292         toc_command->buflen = tocsize;
 293         if (gd.pending) {
 294                 err = -EBUSY;
 295                 goto cleanup_readtoc_final;
 296         }
 297         gd.pending = 1;
 298         gdrom_packetcommand(gd.cd_info, toc_command);
 299         wait_event_interruptible_timeout(command_queue, gd.pending == 0,
 300                 GDROM_DEFAULT_TIMEOUT);
 301         if (gd.pending) {
 302                 err = -EINVAL;
 303                 goto cleanup_readtoc;
 304         }
 305         insw(GDROM_DATA_REG, toc, tocsize/2);
 306         if (gd.status & 0x01)
 307                 err = -EINVAL;
 308
 309 cleanup_readtoc:
 310         gd.pending = 0;
 311 cleanup_readtoc_final:
 312         kfree(toc_command);
 313         return err;
 314 }
 315
 316 /* TOC helpers */
 317 static int get_entry_lba(int track)
 318 {
 319         return (cpu_to_be32(track & 0xffffff00) - GD_SESSION_OFFSET);
 320 }
 321
 322 static int get_entry_q_ctrl(int track)
 323 {
 324         return (track & 0x000000f0) >> 4;
 325 }
 326
 327 static int get_entry_track(int track)
 328 {
 329         return (track & 0x0000ff00) >> 8;
 330 }
 331
 332 static int gdrom_get_last_session(struct cdrom_device_info *cd_info,
 333         struct cdrom_multisession *ms_info)
 334 {
 335         int fentry, lentry, track, data, tocuse, err;
 336         if (!gd.toc)
 337                 return -ENOMEM;
 338         tocuse = 1;
 339         /* Check if GD-ROM */
 340         err = gdrom_readtoc_cmd(gd.toc, 1);
 341         /* Not a GD-ROM so check if standard CD-ROM */
 342         if (err) {
 343                 tocuse = 0;
 344                 err = gdrom_readtoc_cmd(gd.toc, 0);
 345                 if (err) {
 346                         pr_info("Could not get CD table of contents\n");
 347                         return -ENXIO;
 348                 }
 349         }
 350
 351         fentry = get_entry_track(gd.toc->first);
 352         lentry = get_entry_track(gd.toc->last);
 353         /* Find the first data track */
 354         track = get_entry_track(gd.toc->last);
 355         do {
 356                 data = gd.toc->entry[track - 1];
 357                 if (get_entry_q_ctrl(data))
 358                         break;  /* ie a real data track */
 359                 track--;
 360         } while (track >= fentry);
 361
 362         if ((track > 100) || (track < get_entry_track(gd.toc->first))) {
 363                 pr_info("No data on the last session of the CD\n");
 364                 gdrom_getsense(NULL);
 365                 return -ENXIO;
 366         }
 367
 368         ms_info->addr_format = CDROM_LBA;
 369         ms_info->addr.lba = get_entry_lba(data);
 370         ms_info->xa_flag = 1;
 371         return 0;
 372 }
 373
 374 static int gdrom_open(struct cdrom_device_info *cd_info, int purpose)
 375 {
 376         /* spin up the disk */
 377         return gdrom_preparedisk_cmd();
 378 }
 379
 380 /* this function is required even if empty */
 381 static void gdrom_release(struct cdrom_device_info *cd_info)
 382 {
 383 }
 384
 385 static int gdrom_drivestatus(struct cdrom_device_info *cd_info, int ignore)
 386 {
 387         /* read the sense key */
 388         char sense = ctrl_inb(GDROM_ERROR_REG);
 389         sense &= 0xF0;
 390         if (sense == 0)
 391                 return CDS_DISC_OK;
 392         if (sense == 0x20)
 393                 return CDS_DRIVE_NOT_READY;
 394         /* default */
 395         return CDS_NO_INFO;
 396 }
 397
 398 static int gdrom_mediachanged(struct cdrom_device_info *cd_info, int ignore)
 399 {
 400         /* check the sense key */
 401         return (ctrl_inb(GDROM_ERROR_REG) & 0xF0) == 0x60;
 402 }
 403
 404 /* reset the G1 bus */
 405 static int gdrom_hardreset(struct cdrom_device_info *cd_info)
 406 {
 407         int count;
 408         ctrl_outl(0x1fffff, GDROM_RESET_REG);
 409         for (count = 0xa0000000; count < 0xa0200000; count += 4)
 410                 ctrl_inl(count);
 411         return 0;
 412 }
 413
 414 /* keep the function looking like the universal
 415  * CD Rom specification  - returning int */
 416 static int gdrom_packetcommand(struct cdrom_device_info *cd_info,
 417         struct packet_command *command)
 418 {
 419         gdrom_spicommand(&command->cmd, command->buflen);
 420         return 0;
 421 }
 422
 423 /* Get Sense SPI command
 424  * From Marcus Comstedt
 425  * cmd = 0x13
 426  * cmd + 4 = length of returned buffer
 427  * Returns 5 16 bit words
 428  */
 429 static int gdrom_getsense(short *bufstring)
 430 {
 431         struct packet_command *sense_command;
 432         short sense[5];
 433         int sense_key;
 434         int err = -EIO;
 435
 436         sense_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
 437         if (!sense_command)
 438                 return -ENOMEM;
 439         sense_command->cmd[0] = 0x13;
 440         sense_command->cmd[4] = 10;
 441         sense_command->buflen = 10;
 442         /* even if something is pending try to get
 443         * the sense key if possible */
 444         if (gd.pending && !gdrom_wait_clrbusy()) {
 445                 err = -EBUSY;
 446                 goto cleanup_sense_final;
 447         }
 448         gd.pending = 1;
 449         gdrom_packetcommand(gd.cd_info, sense_command);
 450         wait_event_interruptible_timeout(command_queue, gd.pending == 0,
 451                 GDROM_DEFAULT_TIMEOUT);
 452         if (gd.pending)
 453                 goto cleanup_sense;
 454         insw(GDROM_DATA_REG, &sense, sense_command->buflen/2);
 455         if (sense[1] & 40) {
 456                 pr_info("Drive not ready - command aborted\n");
 457                 goto cleanup_sense;
 458         }
 459         sense_key = sense[1] & 0x0F;
 460         if (sense_key < ARRAY_SIZE(sense_texts))
 461                 pr_info("%s\n", sense_texts[sense_key].text);
 462         else
 463                 pr_err("Unknown sense key: %d\n", sense_key);
 464         if (bufstring) /* return addional sense data */
 465                 memcpy(bufstring, &sense[4], 2);
 466         if (sense_key < 2)
 467                 err = 0;
 468
 469 cleanup_sense:
 470         gd.pending = 0;
 471 cleanup_sense_final:
 472         kfree(sense_command);
 473         return err;
 474 }
 475
 476 static int gdrom_audio_ioctl(struct cdrom_device_info *cdi, unsigned int cmd,
 477                              void *arg)
 478 {
 479         return -EINVAL;
 480 }
 481
 482 static struct cdrom_device_ops gdrom_ops = {
 483         .open                   = gdrom_open,
 484         .release                = gdrom_release,
 485         .drive_status           = gdrom_drivestatus,
 486         .media_changed          = gdrom_mediachanged,
 487         .get_last_session       = gdrom_get_last_session,
 488         .reset                  = gdrom_hardreset,
 489         .audio_ioctl            = gdrom_audio_ioctl,
 490         .capability             = CDC_MULTI_SESSION | CDC_MEDIA_CHANGED |
 491                                   CDC_RESET | CDC_DRIVE_STATUS | CDC_CD_R,
 492         .n_minors               = 1,
 493 };
 494
 495 static int gdrom_bdops_open(struct block_device *bdev, fmode_t mode)
 496 {
 497         int ret;
 498         mutex_lock(&gdrom_mutex);
 499         ret = cdrom_open(gd.cd_info, bdev, mode);
 500         mutex_unlock(&gdrom_mutex);
 501         return ret;
 502 }
 503
 504 static int gdrom_bdops_release(struct gendisk *disk, fmode_t mode)
 505 {
 506         mutex_lock(&gdrom_mutex);
 507         cdrom_release(gd.cd_info, mode);
 508         mutex_unlock(&gdrom_mutex);
 509         return 0;
 510 }
 511
 512 static int gdrom_bdops_mediachanged(struct gendisk *disk)
 513 {
 514         return cdrom_media_changed(gd.cd_info);
 515 }
 516
 517 static int gdrom_bdops_ioctl(struct block_device *bdev, fmode_t mode,
 518         unsigned cmd, unsigned long arg)
 519 {
 520         int ret;
 521
 522         mutex_lock(&gdrom_mutex);
 523         ret = cdrom_ioctl(gd.cd_info, bdev, mode, cmd, arg);
 524         mutex_unlock(&gdrom_mutex);
 525
 526         return ret;
 527 }
 528
 529 static const struct block_device_operations gdrom_bdops = {
 530         .owner                  = THIS_MODULE,
 531         .open                   = gdrom_bdops_open,
 532         .release                = gdrom_bdops_release,
 533         .media_changed          = gdrom_bdops_mediachanged,
 534         .ioctl                  = gdrom_bdops_ioctl,
 535 };
 536
 537 static irqreturn_t gdrom_command_interrupt(int irq, void *dev_id)
 538 {
 539         gd.status = ctrl_inb(GDROM_STATUSCOMMAND_REG);
 540         if (gd.pending != 1)
 541                 return IRQ_HANDLED;
 542         gd.pending = 0;
 543         wake_up_interruptible(&command_queue);
 544         return IRQ_HANDLED;
 545 }
 546
 547 static irqreturn_t gdrom_dma_interrupt(int irq, void *dev_id)
 548 {
 549         gd.status = ctrl_inb(GDROM_STATUSCOMMAND_REG);
 550         if (gd.transfer != 1)
 551                 return IRQ_HANDLED;
 552         gd.transfer = 0;
 553         wake_up_interruptible(&request_queue);
 554         return IRQ_HANDLED;
 555 }
 556
 557 static int __devinit gdrom_set_interrupt_handlers(void)
 558 {
 559         int err;
 560
 561         err = request_irq(HW_EVENT_GDROM_CMD, gdrom_command_interrupt,
 562                 IRQF_DISABLED, "gdrom_command", &gd);
 563         if (err)
 564                 return err;
 565         err = request_irq(HW_EVENT_GDROM_DMA, gdrom_dma_interrupt,
 566                 IRQF_DISABLED, "gdrom_dma", &gd);
 567         if (err)
 568                 free_irq(HW_EVENT_GDROM_CMD, &gd);
 569         return err;
 570 }
 571
 572 /* Implement DMA read using SPI command
 573  * 0 -> 0x30
 574  * 1 -> mode
 575  * 2 -> block >> 16
 576  * 3 -> block >> 8
 577  * 4 -> block
 578  * 8 -> sectors >> 16
 579  * 9 -> sectors >> 8
 580  * 10 -> sectors
 581  */
 582 static void gdrom_readdisk_dma(struct work_struct *work)
 583 {
 584         int err, block, block_cnt;
 585         struct packet_command *read_command;
 586         struct list_head *elem, *next;
 587         struct request *req;
 588         unsigned long timeout;
 589
 590         if (list_empty(&gdrom_deferred))
 591                 return;
 592         read_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
 593         if (!read_command)
 594                 return; /* get more memory later? */
 595         read_command->cmd[0] = 0x30;
 596         read_command->cmd[1] = 0x20;
 597         spin_lock(&gdrom_lock);
 598         list_for_each_safe(elem, next, &gdrom_deferred) {
 599                 req = list_entry(elem, struct request, queuelist);
 600                 spin_unlock(&gdrom_lock);
 601                 block = blk_rq_pos(req)/GD_TO_BLK + GD_SESSION_OFFSET;
 602                 block_cnt = blk_rq_sectors(req)/GD_TO_BLK;
 603                 ctrl_outl(virt_to_phys(req->buffer), GDROM_DMA_STARTADDR_REG);
 604                 ctrl_outl(block_cnt * GDROM_HARD_SECTOR, GDROM_DMA_LENGTH_REG);
 605                 ctrl_outl(1, GDROM_DMA_DIRECTION_REG);
 606                 ctrl_outl(1, GDROM_DMA_ENABLE_REG);
 607                 read_command->cmd[2] = (block >> 16) & 0xFF;
 608                 read_command->cmd[3] = (block >> 8) & 0xFF;
 609                 read_command->cmd[4] = block & 0xFF;
 610                 read_command->cmd[8] = (block_cnt >> 16) & 0xFF;
 611                 read_command->cmd[9] = (block_cnt >> 8) & 0xFF;
 612                 read_command->cmd[10] = block_cnt & 0xFF;
 613                 /* set for DMA */
 614                 ctrl_outb(1, GDROM_ERROR_REG);
 615                 /* other registers */
 616                 ctrl_outb(0, GDROM_SECNUM_REG);
 617                 ctrl_outb(0, GDROM_BCL_REG);
 618                 ctrl_outb(0, GDROM_BCH_REG);
 619                 ctrl_outb(0, GDROM_DSEL_REG);
 620                 ctrl_outb(0, GDROM_INTSEC_REG);
 621                 /* Wait for registers to reset after any previous activity */
 622                 timeout = jiffies + HZ / 2;
 623                 while (gdrom_is_busy() && time_before(jiffies, timeout))
 624                         cpu_relax();
 625                 ctrl_outb(GDROM_COM_PACKET, GDROM_STATUSCOMMAND_REG);
 626                 timeout = jiffies + HZ / 2;
 627                 /* Wait for packet command to finish */
 628                 while (gdrom_is_busy() && time_before(jiffies, timeout))
 629                         cpu_relax();
 630                 gd.pending = 1;
 631                 gd.transfer = 1;
 632                 outsw(GDROM_DATA_REG, &read_command->cmd, 6);
 633                 timeout = jiffies + HZ / 2;
 634                 /* Wait for any pending DMA to finish */
 635                 while (ctrl_inb(GDROM_DMA_STATUS_REG) &&
 636                         time_before(jiffies, timeout))
 637                         cpu_relax();
 638                 /* start transfer */
 639                 ctrl_outb(1, GDROM_DMA_STATUS_REG);
 640                 wait_event_interruptible_timeout(request_queue,
 641                         gd.transfer == 0, GDROM_DEFAULT_TIMEOUT);
 642                 err = gd.transfer ? -EIO : 0;
 643                 gd.transfer = 0;
 644                 gd.pending = 0;
 645                 /* now seek to take the request spinlock
 646                 * before handling ending the request */
 647                 spin_lock(&gdrom_lock);
 648                 list_del_init(&req->queuelist);
 649                 __blk_end_request_all(req, err);
 650         }
 651         spin_unlock(&gdrom_lock);
 652         kfree(read_command);
 653 }
 654
 655 static void gdrom_request(struct request_queue *rq)
 656 {
 657         struct request *req;
 658
 659         while ((req = blk_fetch_request(rq)) != NULL) {
 660                 if (req->cmd_type != REQ_TYPE_FS) {
 661                         printk(KERN_DEBUG "gdrom: Non-fs request ignored\n");
 662                         __blk_end_request_all(req, -EIO);
 663                         continue;
 664                 }
 665                 if (rq_data_dir(req) != READ) {
 666                         pr_notice("Read only device - write request ignored\n");
 667                         __blk_end_request_all(req, -EIO);
 668                         continue;
 669                 }
 670
 671                 /*
 672                  * Add to list of deferred work and then schedule
 673                  * workqueue.
 674                  */
 675                 list_add_tail(&req->queuelist, &gdrom_deferred);
 676                 schedule_work(&work);
 677         }
 678 }
 679
 680 /* Print string identifying GD ROM device */
 681 static int __devinit gdrom_outputversion(void)
 682 {
 683         struct gdrom_id *id;
 684         char *model_name, *manuf_name, *firmw_ver;
 685         int err = -ENOMEM;
 686
 687         /* query device ID */
 688         id = kzalloc(sizeof(struct gdrom_id), GFP_KERNEL);
 689         if (!id)
 690                 return err;
 691         gdrom_identifydevice(id);
 692         model_name = kstrndup(id->modname, 16, GFP_KERNEL);
 693         if (!model_name)
 694                 goto free_id;
 695         manuf_name = kstrndup(id->mname, 16, GFP_KERNEL);
 696         if (!manuf_name)
 697                 goto free_model_name;
 698         firmw_ver = kstrndup(id->firmver, 16, GFP_KERNEL);
 699         if (!firmw_ver)
 700                 goto free_manuf_name;
 701         pr_info("%s from %s with firmware %s\n",
 702                 model_name, manuf_name, firmw_ver);
 703         err = 0;
 704         kfree(firmw_ver);
 705 free_manuf_name:
 706         kfree(manuf_name);
 707 free_model_name:
 708         kfree(model_name);
 709 free_id:
 710         kfree(id);
 711         return err;
 712 }
 713
 714 /* set the default mode for DMA transfer */
 715 static int __devinit gdrom_init_dma_mode(void)
 716 {
 717         ctrl_outb(0x13, GDROM_ERROR_REG);
 718         ctrl_outb(0x22, GDROM_INTSEC_REG);
 719         if (!gdrom_wait_clrbusy())
 720                 return -EBUSY;
 721         ctrl_outb(0xEF, GDROM_STATUSCOMMAND_REG);
 722         if (!gdrom_wait_busy_sleeps())
 723                 return -EBUSY;
 724         /* Memory protection setting for GDROM DMA
 725         * Bits 31 - 16 security: 0x8843
 726         * Bits 15 and 7 reserved (0)
 727         * Bits 14 - 8 start of transfer range in 1 MB blocks OR'ed with 0x80
 728         * Bits 6 - 0 end of transfer range in 1 MB blocks OR'ed with 0x80
 729         * (0x40 | 0x80) = start range at 0x0C000000
 730         * (0x7F | 0x80) = end range at 0x0FFFFFFF */
 731         ctrl_outl(0x8843407F, GDROM_DMA_ACCESS_CTRL_REG);
 732         ctrl_outl(9, GDROM_DMA_WAIT_REG); /* DMA word setting */
 733         return 0;
 734 }
 735
 736 static void __devinit probe_gdrom_setupcd(void)
 737 {
 738         gd.cd_info->ops = &gdrom_ops;
 739         gd.cd_info->capacity = 1;
 740         strcpy(gd.cd_info->name, GDROM_DEV_NAME);
 741         gd.cd_info->mask = CDC_CLOSE_TRAY|CDC_OPEN_TRAY|CDC_LOCK|
 742                 CDC_SELECT_DISC;
 743 }
 744
 745 static void __devinit probe_gdrom_setupdisk(void)
 746 {
 747         gd.disk->major = gdrom_major;
 748         gd.disk->first_minor = 1;
 749         gd.disk->minors = 1;
 750         strcpy(gd.disk->disk_name, GDROM_DEV_NAME);
 751 }
 752
 753 static int __devinit probe_gdrom_setupqueue(void)
 754 {
 755         blk_queue_logical_block_size(gd.gdrom_rq, GDROM_HARD_SECTOR);
 756         /* using DMA so memory will need to be contiguous */
 757         blk_queue_max_segments(gd.gdrom_rq, 1);
 758         /* set a large max size to get most from DMA */
 759         blk_queue_max_segment_size(gd.gdrom_rq, 0x40000);
 760         gd.disk->queue = gd.gdrom_rq;
 761         return gdrom_init_dma_mode();
 762 }
 763
 764 /*
 765  * register this as a block device and as compliant with the
 766  * universal CD Rom driver interface
 767  */
 768 static int __devinit probe_gdrom(struct platform_device *devptr)
 769 {
 770         int err;
 771         /* Start the device */
 772         if (gdrom_execute_diagnostic() != 1) {
 773                 pr_warning("ATA Probe for GDROM failed\n");
 774                 return -ENODEV;
 775         }
 776         /* Print out firmware ID */
 777         if (gdrom_outputversion())
 778                 return -ENOMEM;
 779         /* Register GDROM */
 780         gdrom_major = register_blkdev(0, GDROM_DEV_NAME);
 781         if (gdrom_major <= 0)
 782                 return gdrom_major;
 783         pr_info("Registered with major number %d\n",
 784                 gdrom_major);
 785         /* Specify basic properties of drive */
 786         gd.cd_info = kzalloc(sizeof(struct cdrom_device_info), GFP_KERNEL);
 787         if (!gd.cd_info) {
 788                 err = -ENOMEM;
 789                 goto probe_fail_no_mem;
 790         }
 791         probe_gdrom_setupcd();
 792         gd.disk = alloc_disk(1);
 793         if (!gd.disk) {
 794                 err = -ENODEV;
 795                 goto probe_fail_no_disk;
 796         }
 797         probe_gdrom_setupdisk();
 798         if (register_cdrom(gd.cd_info)) {
 799                 err = -ENODEV;
 800                 goto probe_fail_cdrom_register;
 801         }
 802         gd.disk->fops = &gdrom_bdops;
 803         /* latch on to the interrupt */
 804         err = gdrom_set_interrupt_handlers();
 805         if (err)
 806                 goto probe_fail_cmdirq_register;
 807         gd.gdrom_rq = blk_init_queue(gdrom_request, &gdrom_lock);
 808         if (!gd.gdrom_rq)
 809                 goto probe_fail_requestq;
 810
 811         err = probe_gdrom_setupqueue();
 812         if (err)
 813                 goto probe_fail_toc;
 814
 815         gd.toc = kzalloc(sizeof(struct gdromtoc), GFP_KERNEL);
 816         if (!gd.toc)
 817                 goto probe_fail_toc;
 818         add_disk(gd.disk);
 819         return 0;
 820
 821 probe_fail_toc:
 822         blk_cleanup_queue(gd.gdrom_rq);
 823 probe_fail_requestq:
 824         free_irq(HW_EVENT_GDROM_DMA, &gd);
 825         free_irq(HW_EVENT_GDROM_CMD, &gd);
 826 probe_fail_cmdirq_register:
 827 probe_fail_cdrom_register:
 828         del_gendisk(gd.disk);
 829 probe_fail_no_disk:
 830         kfree(gd.cd_info);
 831         unregister_blkdev(gdrom_major, GDROM_DEV_NAME);
 832         gdrom_major = 0;
 833 probe_fail_no_mem:
 834         pr_warning("Probe failed - error is 0x%X\n", err);
 835         return err;
 836 }
 837
 838 static int __devexit remove_gdrom(struct platform_device *devptr)
 839 {
 840         flush_scheduled_work();
 841         blk_cleanup_queue(gd.gdrom_rq);
 842         free_irq(HW_EVENT_GDROM_CMD, &gd);
 843         free_irq(HW_EVENT_GDROM_DMA, &gd);
 844         del_gendisk(gd.disk);
 845         if (gdrom_major)
 846                 unregister_blkdev(gdrom_major, GDROM_DEV_NAME);
 847         unregister_cdrom(gd.cd_info);
 848
 849         return 0;
 850 }
 851
 852 static struct platform_driver gdrom_driver = {
 853         .probe = probe_gdrom,
 854         .remove = __devexit_p(remove_gdrom),
 855         .driver = {
 856                         .name = GDROM_DEV_NAME,
 857         },
 858 };
 859
 860 static int __init init_gdrom(void)
 861 {
 862         int rc;
 863         gd.toc = NULL;
 864         rc = platform_driver_register(&gdrom_driver);
 865         if (rc)
 866                 return rc;
 867         pd = platform_device_register_simple(GDROM_DEV_NAME, -1, NULL, 0);
 868         if (IS_ERR(pd)) {
 869                 platform_driver_unregister(&gdrom_driver);
 870                 return PTR_ERR(pd);
 871         }
 872         return 0;
 873 }
 874
 875 static void __exit exit_gdrom(void)
 876 {
 877         platform_device_unregister(pd);
 878         platform_driver_unregister(&gdrom_driver);
 879         kfree(gd.toc);
 880 }
 881
 882 module_init(init_gdrom);
 883 module_exit(exit_gdrom);
 884 MODULE_AUTHOR("Adrian McMenamin <adrian@mcmen.demon.co.uk>");
 885 MODULE_DESCRIPTION("SEGA Dreamcast GD-ROM Driver");
 886 MODULE_LICENSE("GPL");