summaryrefslogtreecommitdiff
path: root/drivers/cdrom/gdrom.c
blob: b45c543c571acf10bf87991e45cb50ad850186da (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
/* GD ROM driver for the SEGA Dreamcast
 * copyright Adrian McMenamin, 2007
 * With thanks to Marcus Comstedt and Nathan Keynes
 * for work in reversing PIO and DMA
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/init.h>
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/dma-mapping.h>
#include <linux/cdrom.h>
#include <linux/genhd.h>
#include <linux/bio.h>
#include <linux/blk-mq.h>
#include <linux/interrupt.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/wait.h>
#include <linux/platform_device.h>
#include <scsi/scsi.h>
#include <asm/io.h>
#include <asm/dma.h>
#include <asm/delay.h>
#include <mach/dma.h>
#include <mach/sysasic.h>

#define GDROM_DEV_NAME "gdrom"
#define GD_SESSION_OFFSET 150

/* GD Rom commands */
#define GDROM_COM_SOFTRESET 0x08
#define GDROM_COM_EXECDIAG 0x90
#define GDROM_COM_PACKET 0xA0
#define GDROM_COM_IDDEV 0xA1

/* GD Rom registers */
#define GDROM_BASE_REG			0xA05F7000
#define GDROM_ALTSTATUS_REG		(GDROM_BASE_REG + 0x18)
#define GDROM_DATA_REG			(GDROM_BASE_REG + 0x80)
#define GDROM_ERROR_REG		(GDROM_BASE_REG + 0x84)
#define GDROM_INTSEC_REG		(GDROM_BASE_REG + 0x88)
#define GDROM_SECNUM_REG		(GDROM_BASE_REG + 0x8C)
#define GDROM_BCL_REG			(GDROM_BASE_REG + 0x90)
#define GDROM_BCH_REG			(GDROM_BASE_REG + 0x94)
#define GDROM_DSEL_REG			(GDROM_BASE_REG + 0x98)
#define GDROM_STATUSCOMMAND_REG	(GDROM_BASE_REG + 0x9C)
#define GDROM_RESET_REG		(GDROM_BASE_REG + 0x4E4)

#define GDROM_DMA_STARTADDR_REG	(GDROM_BASE_REG + 0x404)
#define GDROM_DMA_LENGTH_REG		(GDROM_BASE_REG + 0x408)
#define GDROM_DMA_DIRECTION_REG	(GDROM_BASE_REG + 0x40C)
#define GDROM_DMA_ENABLE_REG		(GDROM_BASE_REG + 0x414)
#define GDROM_DMA_STATUS_REG		(GDROM_BASE_REG + 0x418)
#define GDROM_DMA_WAIT_REG		(GDROM_BASE_REG + 0x4A0)
#define GDROM_DMA_ACCESS_CTRL_REG	(GDROM_BASE_REG + 0x4B8)

#define GDROM_HARD_SECTOR	2048
#define BLOCK_LAYER_SECTOR	512
#define GD_TO_BLK		4

#define GDROM_DEFAULT_TIMEOUT	(HZ * 7)

static DEFINE_MUTEX(gdrom_mutex);
static const struct {
	int sense_key;
	const char * const text;
} sense_texts[] = {
	{NO_SENSE, "OK"},
	{RECOVERED_ERROR, "Recovered from error"},
	{NOT_READY, "Device not ready"},
	{MEDIUM_ERROR, "Disk not ready"},
	{HARDWARE_ERROR, "Hardware error"},
	{ILLEGAL_REQUEST, "Command has failed"},
	{UNIT_ATTENTION, "Device needs attention - disk may have been changed"},
	{DATA_PROTECT, "Data protection error"},
	{ABORTED_COMMAND, "Command aborted"},
};

static struct platform_device *pd;
static int gdrom_major;
static DECLARE_WAIT_QUEUE_HEAD(command_queue);
static DECLARE_WAIT_QUEUE_HEAD(request_queue);

struct gdromtoc {
	unsigned int entry[99];
	unsigned int first, last;
	unsigned int leadout;
};

static struct gdrom_unit {
	struct gendisk *disk;
	struct cdrom_device_info *cd_info;
	int status;
	int pending;
	int transfer;
	char disk_type;
	struct gdromtoc *toc;
	struct request_queue *gdrom_rq;
	struct blk_mq_tag_set tag_set;
} gd;

struct gdrom_id {
	char mid;
	char modid;
	char verid;
	char padA[13];
	char mname[16];
	char modname[16];
	char firmver[16];
	char padB[16];
};

static int gdrom_getsense(short *bufstring);
static int gdrom_packetcommand(struct cdrom_device_info *cd_info,
	struct packet_command *command);
static int gdrom_hardreset(struct cdrom_device_info *cd_info);

static bool gdrom_is_busy(void)
{
	return (__raw_readb(GDROM_ALTSTATUS_REG) & 0x80) != 0;
}

static bool gdrom_data_request(void)
{
	return (__raw_readb(GDROM_ALTSTATUS_REG) & 0x88) == 8;
}

static bool gdrom_wait_clrbusy(void)
{
	unsigned long timeout = jiffies + GDROM_DEFAULT_TIMEOUT;
	while ((__raw_readb(GDROM_ALTSTATUS_REG) & 0x80) &&
		(time_before(jiffies, timeout)))
		cpu_relax();
	return time_before(jiffies, timeout + 1);
}

static bool gdrom_wait_busy_sleeps(void)
{
	unsigned long timeout;
	/* Wait to get busy first */
	timeout = jiffies + GDROM_DEFAULT_TIMEOUT;
	while (!gdrom_is_busy() && time_before(jiffies, timeout))
		cpu_relax();
	/* Now wait for busy to clear */
	return gdrom_wait_clrbusy();
}

static void gdrom_identifydevice(void *buf)
{
	int c;
	short *data = buf;
	/* If the device won't clear it has probably
	* been hit by a serious failure - but we'll
	* try to return a sense key even so */
	if (!gdrom_wait_clrbusy()) {
		gdrom_getsense(NULL);
		return;
	}
	__raw_writeb(GDROM_COM_IDDEV, GDROM_STATUSCOMMAND_REG);
	if (!gdrom_wait_busy_sleeps()) {
		gdrom_getsense(NULL);
		return;
	}
	/* now read in the data */
	for (c = 0; c < 40; c++)
		data[c] = __raw_readw(GDROM_DATA_REG);
}

static void gdrom_spicommand(void *spi_string, int buflen)
{
	short *cmd = spi_string;
	unsigned long timeout;

	/* ensure IRQ_WAIT is set */
	__raw_writeb(0x08, GDROM_ALTSTATUS_REG);
	/* specify how many bytes we expect back */
	__raw_writeb(buflen & 0xFF, GDROM_BCL_REG);
	__raw_writeb((buflen >> 8) & 0xFF, GDROM_BCH_REG);
	/* other parameters */
	__raw_writeb(0, GDROM_INTSEC_REG);
	__raw_writeb(0, GDROM_SECNUM_REG);
	__raw_writeb(0, GDROM_ERROR_REG);
	/* Wait until we can go */
	if (!gdrom_wait_clrbusy()) {
		gdrom_getsense(NULL);
		return;
	}
	timeout = jiffies + GDROM_DEFAULT_TIMEOUT;
	__raw_writeb(GDROM_COM_PACKET, GDROM_STATUSCOMMAND_REG);
	while (!gdrom_data_request() && time_before(jiffies, timeout))
		cpu_relax();
	if (!time_before(jiffies, timeout + 1)) {
		gdrom_getsense(NULL);
		return;
	}
	outsw(GDROM_DATA_REG, cmd, 6);
}


/* gdrom_command_executediagnostic:
 * Used to probe for presence of working GDROM
 * Restarts GDROM device and then applies standard ATA 3
 * Execute Diagnostic Command: a return of '1' indicates device 0
 * present and device 1 absent
 */
static char gdrom_execute_diagnostic(void)
{
	gdrom_hardreset(gd.cd_info);
	if (!gdrom_wait_clrbusy())
		return 0;
	__raw_writeb(GDROM_COM_EXECDIAG, GDROM_STATUSCOMMAND_REG);
	if (!gdrom_wait_busy_sleeps())
		return 0;
	return __raw_readb(GDROM_ERROR_REG);
}

/*
 * Prepare disk command
 * byte 0 = 0x70
 * byte 1 = 0x1f
 */
static int gdrom_preparedisk_cmd(void)
{
	struct packet_command *spin_command;
	spin_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
	if (!spin_command)
		return -ENOMEM;
	spin_command->cmd[0] = 0x70;
	spin_command->cmd[2] = 0x1f;
	spin_command->buflen = 0;
	gd.pending = 1;
	gdrom_packetcommand(gd.cd_info, spin_command);
	/* 60 second timeout */
	wait_event_interruptible_timeout(command_queue, gd.pending == 0,
		GDROM_DEFAULT_TIMEOUT);
	gd.pending = 0;
	kfree(spin_command);
	if (gd.status & 0x01) {
		/* log an error */
		gdrom_getsense(NULL);
		return -EIO;
	}
	return 0;
}

/*
 * Read TOC command
 * byte 0 = 0x14
 * byte 1 = session
 * byte 3 = sizeof TOC >> 8  ie upper byte
 * byte 4 = sizeof TOC & 0xff ie lower byte
 */
static int gdrom_readtoc_cmd(struct gdromtoc *toc, int session)
{
	int tocsize;
	struct packet_command *toc_command;
	int err = 0;

	toc_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
	if (!toc_command)
		return -ENOMEM;
	tocsize = sizeof(struct gdromtoc);
	toc_command->cmd[0] = 0x14;
	toc_command->cmd[1] = session;
	toc_command->cmd[3] = tocsize >> 8;
	toc_command->cmd[4] = tocsize & 0xff;
	toc_command->buflen = tocsize;
	if (gd.pending) {
		err = -EBUSY;
		goto cleanup_readtoc_final;
	}
	gd.pending = 1;
	gdrom_packetcommand(gd.cd_info, toc_command);
	wait_event_interruptible_timeout(command_queue, gd.pending == 0,
		GDROM_DEFAULT_TIMEOUT);
	if (gd.pending) {
		err = -EINVAL;
		goto cleanup_readtoc;
	}
	insw(GDROM_DATA_REG, toc, tocsize/2);
	if (gd.status & 0x01)
		err = -EINVAL;

cleanup_readtoc:
	gd.pending = 0;
cleanup_readtoc_final:
	kfree(toc_command);
	return err;
}

/* TOC helpers */
static int get_entry_lba(int track)
{
	return (cpu_to_be32(track & 0xffffff00) - GD_SESSION_OFFSET);
}

static int get_entry_q_ctrl(int track)
{
	return (track & 0x000000f0) >> 4;
}

static int get_entry_track(int track)
{
	return (track & 0x0000ff00) >> 8;
}

static int gdrom_get_last_session(struct cdrom_device_info *cd_info,
	struct cdrom_multisession *ms_info)
{
	int fentry, lentry, track, data, err;

	if (!gd.toc)
		return -ENOMEM;

	/* Check if GD-ROM */
	err = gdrom_readtoc_cmd(gd.toc, 1);
	/* Not a GD-ROM so check if standard CD-ROM */
	if (err) {
		err = gdrom_readtoc_cmd(gd.toc, 0);
		if (err) {
			pr_info("Could not get CD table of contents\n");
			return -ENXIO;
		}
	}

	fentry = get_entry_track(gd.toc->first);
	lentry = get_entry_track(gd.toc->last);
	/* Find the first data track */
	track = get_entry_track(gd.toc->last);
	do {
		data = gd.toc->entry[track - 1];
		if (get_entry_q_ctrl(data))
			break;	/* ie a real data track */
		track--;
	} while (track >= fentry);

	if ((track > 100) || (track < get_entry_track(gd.toc->first))) {
		pr_info("No data on the last session of the CD\n");
		gdrom_getsense(NULL);
		return -ENXIO;
	}

	ms_info->addr_format = CDROM_LBA;
	ms_info->addr.lba = get_entry_lba(data);
	ms_info->xa_flag = 1;
	return 0;
}

static int gdrom_open(struct cdrom_device_info *cd_info, int purpose)
{
	/* spin up the disk */
	return gdrom_preparedisk_cmd();
}

/* this function is required even if empty */
static void gdrom_release(struct cdrom_device_info *cd_info)
{
}

static int gdrom_drivestatus(struct cdrom_device_info *cd_info, int ignore)
{
	/* read the sense key */
	char sense = __raw_readb(GDROM_ERROR_REG);
	sense &= 0xF0;
	if (sense == 0)
		return CDS_DISC_OK;
	if (sense == 0x20)
		return CDS_DRIVE_NOT_READY;
	/* default */
	return CDS_NO_INFO;
}

static unsigned int gdrom_check_events(struct cdrom_device_info *cd_info,
				       unsigned int clearing, int ignore)
{
	/* check the sense key */
	return (__raw_readb(GDROM_ERROR_REG) & 0xF0) == 0x60 ?
		DISK_EVENT_MEDIA_CHANGE : 0;
}

/* reset the G1 bus */
static int gdrom_hardreset(struct cdrom_device_info *cd_info)
{
	int count;
	__raw_writel(0x1fffff, GDROM_RESET_REG);
	for (count = 0xa0000000; count < 0xa0200000; count += 4)
		__raw_readl(count);
	return 0;
}

/* keep the function looking like the universal
 * CD Rom specification  - returning int */
static int gdrom_packetcommand(struct cdrom_device_info *cd_info,
	struct packet_command *command)
{
	gdrom_spicommand(&command->cmd, command->buflen);
	return 0;
}

/* Get Sense SPI command
 * From Marcus Comstedt
 * cmd = 0x13
 * cmd + 4 = length of returned buffer
 * Returns 5 16 bit words
 */
static int gdrom_getsense(short *bufstring)
{
	struct packet_command *sense_command;
	short sense[5];
	int sense_key;
	int err = -EIO;

	sense_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
	if (!sense_command)
		return -ENOMEM;
	sense_command->cmd[0] = 0x13;
	sense_command->cmd[4] = 10;
	sense_command->buflen = 10;
	/* even if something is pending try to get
	* the sense key if possible */
	if (gd.pending && !gdrom_wait_clrbusy()) {
		err = -EBUSY;
		goto cleanup_sense_final;
	}
	gd.pending = 1;
	gdrom_packetcommand(gd.cd_info, sense_command);
	wait_event_interruptible_timeout(command_queue, gd.pending == 0,
		GDROM_DEFAULT_TIMEOUT);
	if (gd.pending)
		goto cleanup_sense;
	insw(GDROM_DATA_REG, &sense, sense_command->buflen/2);
	if (sense[1] & 40) {
		pr_info("Drive not ready - command aborted\n");
		goto cleanup_sense;
	}
	sense_key = sense[1] & 0x0F;
	if (sense_key < ARRAY_SIZE(sense_texts))
		pr_info("%s\n", sense_texts[sense_key].text);
	else
		pr_err("Unknown sense key: %d\n", sense_key);
	if (bufstring) /* return addional sense data */
		memcpy(bufstring, &sense[4], 2);
	if (sense_key < 2)
		err = 0;

cleanup_sense:
	gd.pending = 0;
cleanup_sense_final:
	kfree(sense_command);
	return err;
}

static int gdrom_audio_ioctl(struct cdrom_device_info *cdi, unsigned int cmd,
			     void *arg)
{
	return -EINVAL;
}

static const struct cdrom_device_ops gdrom_ops = {
	.open			= gdrom_open,
	.release		= gdrom_release,
	.drive_status		= gdrom_drivestatus,
	.check_events		= gdrom_check_events,
	.get_last_session	= gdrom_get_last_session,
	.reset			= gdrom_hardreset,
	.audio_ioctl		= gdrom_audio_ioctl,
	.generic_packet		= cdrom_dummy_generic_packet,
	.capability		= CDC_MULTI_SESSION | CDC_MEDIA_CHANGED |
				  CDC_RESET | CDC_DRIVE_STATUS | CDC_CD_R,
};

static int gdrom_bdops_open(struct block_device *bdev, fmode_t mode)
{
	int ret;

	check_disk_change(bdev);

	mutex_lock(&gdrom_mutex);
	ret = cdrom_open(gd.cd_info, bdev, mode);
	mutex_unlock(&gdrom_mutex);
	return ret;
}

static void gdrom_bdops_release(struct gendisk *disk, fmode_t mode)
{
	mutex_lock(&gdrom_mutex);
	cdrom_release(gd.cd_info, mode);
	mutex_unlock(&gdrom_mutex);
}

static unsigned int gdrom_bdops_check_events(struct gendisk *disk,
					     unsigned int clearing)
{
	return cdrom_check_events(gd.cd_info, clearing);
}

static int gdrom_bdops_ioctl(struct block_device *bdev, fmode_t mode,
	unsigned cmd, unsigned long arg)
{
	int ret;

	mutex_lock(&gdrom_mutex);
	ret = cdrom_ioctl(gd.cd_info, bdev, mode, cmd, arg);
	mutex_unlock(&gdrom_mutex);

	return ret;
}

static const struct block_device_operations gdrom_bdops = {
	.owner			= THIS_MODULE,
	.open			= gdrom_bdops_open,
	.release		= gdrom_bdops_release,
	.check_events		= gdrom_bdops_check_events,
	.ioctl			= gdrom_bdops_ioctl,
};

static irqreturn_t gdrom_command_interrupt(int irq, void *dev_id)
{
	gd.status = __raw_readb(GDROM_STATUSCOMMAND_REG);
	if (gd.pending != 1)
		return IRQ_HANDLED;
	gd.pending = 0;
	wake_up_interruptible(&command_queue);
	return IRQ_HANDLED;
}

static irqreturn_t gdrom_dma_interrupt(int irq, void *dev_id)
{
	gd.status = __raw_readb(GDROM_STATUSCOMMAND_REG);
	if (gd.transfer != 1)
		return IRQ_HANDLED;
	gd.transfer = 0;
	wake_up_interruptible(&request_queue);
	return IRQ_HANDLED;
}

static int gdrom_set_interrupt_handlers(void)
{
	int err;

	err = request_irq(HW_EVENT_GDROM_CMD, gdrom_command_interrupt,
		0, "gdrom_command", &gd);
	if (err)
		return err;
	err = request_irq(HW_EVENT_GDROM_DMA, gdrom_dma_interrupt,
		0, "gdrom_dma", &gd);
	if (err)
		free_irq(HW_EVENT_GDROM_CMD, &gd);
	return err;
}

/* Implement DMA read using SPI command
 * 0 -> 0x30
 * 1 -> mode
 * 2 -> block >> 16
 * 3 -> block >> 8
 * 4 -> block
 * 8 -> sectors >> 16
 * 9 -> sectors >> 8
 * 10 -> sectors
 */
static blk_status_t gdrom_readdisk_dma(struct request *req)
{
	int block, block_cnt;
	blk_status_t err;
	struct packet_command *read_command;
	unsigned long timeout;

	read_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
	if (!read_command)
		return BLK_STS_RESOURCE;

	read_command->cmd[0] = 0x30;
	read_command->cmd[1] = 0x20;
	block = blk_rq_pos(req)/GD_TO_BLK + GD_SESSION_OFFSET;
	block_cnt = blk_rq_sectors(req)/GD_TO_BLK;
	__raw_writel(virt_to_phys(bio_data(req->bio)), GDROM_DMA_STARTADDR_REG);
	__raw_writel(block_cnt * GDROM_HARD_SECTOR, GDROM_DMA_LENGTH_REG);
	__raw_writel(1, GDROM_DMA_DIRECTION_REG);
	__raw_writel(1, GDROM_DMA_ENABLE_REG);
	read_command->cmd[2] = (block >> 16) & 0xFF;
	read_command->cmd[3] = (block >> 8) & 0xFF;
	read_command->cmd[4] = block & 0xFF;
	read_command->cmd[8] = (block_cnt >> 16) & 0xFF;
	read_command->cmd[9] = (block_cnt >> 8) & 0xFF;
	read_command->cmd[10] = block_cnt & 0xFF;
	/* set for DMA */
	__raw_writeb(1, GDROM_ERROR_REG);
	/* other registers */
	__raw_writeb(0, GDROM_SECNUM_REG);
	__raw_writeb(0, GDROM_BCL_REG);
	__raw_writeb(0, GDROM_BCH_REG);
	__raw_writeb(0, GDROM_DSEL_REG);
	__raw_writeb(0, GDROM_INTSEC_REG);
	/* Wait for registers to reset after any previous activity */
	timeout = jiffies + HZ / 2;
	while (gdrom_is_busy() && time_before(jiffies, timeout))
		cpu_relax();
	__raw_writeb(GDROM_COM_PACKET, GDROM_STATUSCOMMAND_REG);
	timeout = jiffies + HZ / 2;
	/* Wait for packet command to finish */
	while (gdrom_is_busy() && time_before(jiffies, timeout))
		cpu_relax();
	gd.pending = 1;
	gd.transfer = 1;
	outsw(GDROM_DATA_REG, &read_command->cmd, 6);
	timeout = jiffies + HZ / 2;
	/* Wait for any pending DMA to finish */
	while (__raw_readb(GDROM_DMA_STATUS_REG) &&
		time_before(jiffies, timeout))
		cpu_relax();
	/* start transfer */
	__raw_writeb(1, GDROM_DMA_STATUS_REG);
	wait_event_interruptible_timeout(request_queue,
		gd.transfer == 0, GDROM_DEFAULT_TIMEOUT);
	err = gd.transfer ? BLK_STS_IOERR : BLK_STS_OK;
	gd.transfer = 0;
	gd.pending = 0;

	blk_mq_end_request(req, err);
	kfree(read_command);
	return BLK_STS_OK;
}

static blk_status_t gdrom_queue_rq(struct blk_mq_hw_ctx *hctx,
				   const struct blk_mq_queue_data *bd)
{
	blk_mq_start_request(bd->rq);

	switch (req_op(bd->rq)) {
	case REQ_OP_READ:
		return gdrom_readdisk_dma(bd->rq);
	case REQ_OP_WRITE:
		pr_notice("Read only device - write request ignored\n");
		return BLK_STS_IOERR;
	default:
		printk(KERN_DEBUG "gdrom: Non-fs request ignored\n");
		return BLK_STS_IOERR;
	}
}

/* Print string identifying GD ROM device */
static int gdrom_outputversion(void)
{
	struct gdrom_id *id;
	char *model_name, *manuf_name, *firmw_ver;
	int err = -ENOMEM;

	/* query device ID */
	id = kzalloc(sizeof(struct gdrom_id), GFP_KERNEL);
	if (!id)
		return err;
	gdrom_identifydevice(id);
	model_name = kstrndup(id->modname, 16, GFP_KERNEL);
	if (!model_name)
		goto free_id;
	manuf_name = kstrndup(id->mname, 16, GFP_KERNEL);
	if (!manuf_name)
		goto free_model_name;
	firmw_ver = kstrndup(id->firmver, 16, GFP_KERNEL);
	if (!firmw_ver)
		goto free_manuf_name;
	pr_info("%s from %s with firmware %s\n",
		model_name, manuf_name, firmw_ver);
	err = 0;
	kfree(firmw_ver);
free_manuf_name:
	kfree(manuf_name);
free_model_name:
	kfree(model_name);
free_id:
	kfree(id);
	return err;
}

/* set the default mode for DMA transfer */
static int gdrom_init_dma_mode(void)
{
	__raw_writeb(0x13, GDROM_ERROR_REG);
	__raw_writeb(0x22, GDROM_INTSEC_REG);
	if (!gdrom_wait_clrbusy())
		return -EBUSY;
	__raw_writeb(0xEF, GDROM_STATUSCOMMAND_REG);
	if (!gdrom_wait_busy_sleeps())
		return -EBUSY;
	/* Memory protection setting for GDROM DMA
	* Bits 31 - 16 security: 0x8843
	* Bits 15 and 7 reserved (0)
	* Bits 14 - 8 start of transfer range in 1 MB blocks OR'ed with 0x80
	* Bits 6 - 0 end of transfer range in 1 MB blocks OR'ed with 0x80
	* (0x40 | 0x80) = start range at 0x0C000000
	* (0x7F | 0x80) = end range at 0x0FFFFFFF */
	__raw_writel(0x8843407F, GDROM_DMA_ACCESS_CTRL_REG);
	__raw_writel(9, GDROM_DMA_WAIT_REG); /* DMA word setting */
	return 0;
}

static void probe_gdrom_setupcd(void)
{
	gd.cd_info->ops = &gdrom_ops;
	gd.cd_info->capacity = 1;
	strcpy(gd.cd_info->name, GDROM_DEV_NAME);
	gd.cd_info->mask = CDC_CLOSE_TRAY|CDC_OPEN_TRAY|CDC_LOCK|
		CDC_SELECT_DISC;
}

static void probe_gdrom_setupdisk(void)
{
	gd.disk->major = gdrom_major;
	gd.disk->first_minor = 1;
	gd.disk->minors = 1;
	strcpy(gd.disk->disk_name, GDROM_DEV_NAME);
}

static int probe_gdrom_setupqueue(void)
{
	blk_queue_logical_block_size(gd.gdrom_rq, GDROM_HARD_SECTOR);
	/* using DMA so memory will need to be contiguous */
	blk_queue_max_segments(gd.gdrom_rq, 1);
	/* set a large max size to get most from DMA */
	blk_queue_max_segment_size(gd.gdrom_rq, 0x40000);
	gd.disk->queue = gd.gdrom_rq;
	return gdrom_init_dma_mode();
}

static const struct blk_mq_ops gdrom_mq_ops = {
	.queue_rq	= gdrom_queue_rq,
};

/*
 * register this as a block device and as compliant with the
 * universal CD Rom driver interface
 */
static int probe_gdrom(struct platform_device *devptr)
{
	int err;
	/* Start the device */
	if (gdrom_execute_diagnostic() != 1) {
		pr_warning("ATA Probe for GDROM failed\n");
		return -ENODEV;
	}
	/* Print out firmware ID */
	if (gdrom_outputversion())
		return -ENOMEM;
	/* Register GDROM */
	gdrom_major = register_blkdev(0, GDROM_DEV_NAME);
	if (gdrom_major <= 0)
		return gdrom_major;
	pr_info("Registered with major number %d\n",
		gdrom_major);
	/* Specify basic properties of drive */
	gd.cd_info = kzalloc(sizeof(struct cdrom_device_info), GFP_KERNEL);
	if (!gd.cd_info) {
		err = -ENOMEM;
		goto probe_fail_no_mem;
	}
	probe_gdrom_setupcd();
	gd.disk = alloc_disk(1);
	if (!gd.disk) {
		err = -ENODEV;
		goto probe_fail_no_disk;
	}
	probe_gdrom_setupdisk();
	if (register_cdrom(gd.cd_info)) {
		err = -ENODEV;
		goto probe_fail_cdrom_register;
	}
	gd.disk->fops = &gdrom_bdops;
	/* latch on to the interrupt */
	err = gdrom_set_interrupt_handlers();
	if (err)
		goto probe_fail_cmdirq_register;

	gd.gdrom_rq = blk_mq_init_sq_queue(&gd.tag_set, &gdrom_mq_ops, 1,
				BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_BLOCKING);
	if (IS_ERR(gd.gdrom_rq)) {
		rc = PTR_ERR(gd.gdrom_rq);
		gd.gdrom_rq = NULL;
		goto probe_fail_requestq;
	}

	blk_queue_bounce_limit(gd.gdrom_rq, BLK_BOUNCE_HIGH);

	err = probe_gdrom_setupqueue();
	if (err)
		goto probe_fail_toc;

	gd.toc = kzalloc(sizeof(struct gdromtoc), GFP_KERNEL);
	if (!gd.toc) {
		err = -ENOMEM;
		goto probe_fail_toc;
	}
	add_disk(gd.disk);
	return 0;

probe_fail_toc:
	blk_cleanup_queue(gd.gdrom_rq);
	blk_mq_free_tag_set(&gd.tag_set);
probe_fail_requestq:
	free_irq(HW_EVENT_GDROM_DMA, &gd);
	free_irq(HW_EVENT_GDROM_CMD, &gd);
probe_fail_cmdirq_register:
probe_fail_cdrom_register:
	del_gendisk(gd.disk);
probe_fail_no_disk:
	kfree(gd.cd_info);
probe_fail_no_mem:
	unregister_blkdev(gdrom_major, GDROM_DEV_NAME);
	gdrom_major = 0;
	pr_warning("Probe failed - error is 0x%X\n", err);
	return err;
}

static int remove_gdrom(struct platform_device *devptr)
{
	blk_cleanup_queue(gd.gdrom_rq);
	blk_mq_free_tag_set(&gd.tag_set);
	free_irq(HW_EVENT_GDROM_CMD, &gd);
	free_irq(HW_EVENT_GDROM_DMA, &gd);
	del_gendisk(gd.disk);
	if (gdrom_major)
		unregister_blkdev(gdrom_major, GDROM_DEV_NAME);
	unregister_cdrom(gd.cd_info);

	return 0;
}

static struct platform_driver gdrom_driver = {
	.probe = probe_gdrom,
	.remove = remove_gdrom,
	.driver = {
			.name = GDROM_DEV_NAME,
	},
};

static int __init init_gdrom(void)
{
	int rc;
	gd.toc = NULL;
	rc = platform_driver_register(&gdrom_driver);
	if (rc)
		return rc;
	pd = platform_device_register_simple(GDROM_DEV_NAME, -1, NULL, 0);
	if (IS_ERR(pd)) {
		platform_driver_unregister(&gdrom_driver);
		return PTR_ERR(pd);
	}
	return 0;
}

static void __exit exit_gdrom(void)
{
	platform_device_unregister(pd);
	platform_driver_unregister(&gdrom_driver);
	kfree(gd.toc);
}

module_init(init_gdrom);
module_exit(exit_gdrom);
MODULE_AUTHOR("Adrian McMenamin <adrian@mcmen.demon.co.uk>");
MODULE_DESCRIPTION("SEGA Dreamcast GD-ROM Driver");
MODULE_LICENSE("GPL");