xref: /linux/drivers/cdrom/gdrom.c (revision 662fa3d6099374c4615bf64d06895e3573b935b2)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* GD ROM driver for the SEGA Dreamcast
3  * copyright Adrian McMenamin, 2007
4  * With thanks to Marcus Comstedt and Nathan Keynes
5  * for work in reversing PIO and DMA
6  */
7 
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9 
10 #include <linux/init.h>
11 #include <linux/module.h>
12 #include <linux/fs.h>
13 #include <linux/kernel.h>
14 #include <linux/list.h>
15 #include <linux/slab.h>
16 #include <linux/dma-mapping.h>
17 #include <linux/cdrom.h>
18 #include <linux/genhd.h>
19 #include <linux/bio.h>
20 #include <linux/blk-mq.h>
21 #include <linux/interrupt.h>
22 #include <linux/device.h>
23 #include <linux/mutex.h>
24 #include <linux/wait.h>
25 #include <linux/platform_device.h>
26 #include <scsi/scsi.h>
27 #include <asm/io.h>
28 #include <asm/dma.h>
29 #include <asm/delay.h>
30 #include <mach/dma.h>
31 #include <mach/sysasic.h>
32 
33 #define GDROM_DEV_NAME "gdrom"
34 #define GD_SESSION_OFFSET 150
35 
36 /* GD Rom commands */
37 #define GDROM_COM_SOFTRESET 0x08
38 #define GDROM_COM_EXECDIAG 0x90
39 #define GDROM_COM_PACKET 0xA0
40 #define GDROM_COM_IDDEV 0xA1
41 
42 /* GD Rom registers */
43 #define GDROM_BASE_REG			0xA05F7000
44 #define GDROM_ALTSTATUS_REG		(GDROM_BASE_REG + 0x18)
45 #define GDROM_DATA_REG			(GDROM_BASE_REG + 0x80)
46 #define GDROM_ERROR_REG		(GDROM_BASE_REG + 0x84)
47 #define GDROM_INTSEC_REG		(GDROM_BASE_REG + 0x88)
48 #define GDROM_SECNUM_REG		(GDROM_BASE_REG + 0x8C)
49 #define GDROM_BCL_REG			(GDROM_BASE_REG + 0x90)
50 #define GDROM_BCH_REG			(GDROM_BASE_REG + 0x94)
51 #define GDROM_DSEL_REG			(GDROM_BASE_REG + 0x98)
52 #define GDROM_STATUSCOMMAND_REG	(GDROM_BASE_REG + 0x9C)
53 #define GDROM_RESET_REG		(GDROM_BASE_REG + 0x4E4)
54 
55 #define GDROM_DMA_STARTADDR_REG	(GDROM_BASE_REG + 0x404)
56 #define GDROM_DMA_LENGTH_REG		(GDROM_BASE_REG + 0x408)
57 #define GDROM_DMA_DIRECTION_REG	(GDROM_BASE_REG + 0x40C)
58 #define GDROM_DMA_ENABLE_REG		(GDROM_BASE_REG + 0x414)
59 #define GDROM_DMA_STATUS_REG		(GDROM_BASE_REG + 0x418)
60 #define GDROM_DMA_WAIT_REG		(GDROM_BASE_REG + 0x4A0)
61 #define GDROM_DMA_ACCESS_CTRL_REG	(GDROM_BASE_REG + 0x4B8)
62 
63 #define GDROM_HARD_SECTOR	2048
64 #define BLOCK_LAYER_SECTOR	512
65 #define GD_TO_BLK		4
66 
67 #define GDROM_DEFAULT_TIMEOUT	(HZ * 7)
68 
69 static DEFINE_MUTEX(gdrom_mutex);
70 static const struct {
71 	int sense_key;
72 	const char * const text;
73 } sense_texts[] = {
74 	{NO_SENSE, "OK"},
75 	{RECOVERED_ERROR, "Recovered from error"},
76 	{NOT_READY, "Device not ready"},
77 	{MEDIUM_ERROR, "Disk not ready"},
78 	{HARDWARE_ERROR, "Hardware error"},
79 	{ILLEGAL_REQUEST, "Command has failed"},
80 	{UNIT_ATTENTION, "Device needs attention - disk may have been changed"},
81 	{DATA_PROTECT, "Data protection error"},
82 	{ABORTED_COMMAND, "Command aborted"},
83 };
84 
85 static struct platform_device *pd;
86 static int gdrom_major;
87 static DECLARE_WAIT_QUEUE_HEAD(command_queue);
88 static DECLARE_WAIT_QUEUE_HEAD(request_queue);
89 
90 struct gdromtoc {
91 	unsigned int entry[99];
92 	unsigned int first, last;
93 	unsigned int leadout;
94 };
95 
96 static struct gdrom_unit {
97 	struct gendisk *disk;
98 	struct cdrom_device_info *cd_info;
99 	int status;
100 	int pending;
101 	int transfer;
102 	char disk_type;
103 	struct gdromtoc *toc;
104 	struct request_queue *gdrom_rq;
105 	struct blk_mq_tag_set tag_set;
106 } gd;
107 
108 struct gdrom_id {
109 	char mid;
110 	char modid;
111 	char verid;
112 	char padA[13];
113 	char mname[16];
114 	char modname[16];
115 	char firmver[16];
116 	char padB[16];
117 };
118 
119 static int gdrom_getsense(short *bufstring);
120 static int gdrom_packetcommand(struct cdrom_device_info *cd_info,
121 	struct packet_command *command);
122 static int gdrom_hardreset(struct cdrom_device_info *cd_info);
123 
124 static bool gdrom_is_busy(void)
125 {
126 	return (__raw_readb(GDROM_ALTSTATUS_REG) & 0x80) != 0;
127 }
128 
129 static bool gdrom_data_request(void)
130 {
131 	return (__raw_readb(GDROM_ALTSTATUS_REG) & 0x88) == 8;
132 }
133 
134 static bool gdrom_wait_clrbusy(void)
135 {
136 	unsigned long timeout = jiffies + GDROM_DEFAULT_TIMEOUT;
137 	while ((__raw_readb(GDROM_ALTSTATUS_REG) & 0x80) &&
138 		(time_before(jiffies, timeout)))
139 		cpu_relax();
140 	return time_before(jiffies, timeout + 1);
141 }
142 
143 static bool gdrom_wait_busy_sleeps(void)
144 {
145 	unsigned long timeout;
146 	/* Wait to get busy first */
147 	timeout = jiffies + GDROM_DEFAULT_TIMEOUT;
148 	while (!gdrom_is_busy() && time_before(jiffies, timeout))
149 		cpu_relax();
150 	/* Now wait for busy to clear */
151 	return gdrom_wait_clrbusy();
152 }
153 
154 static void gdrom_identifydevice(void *buf)
155 {
156 	int c;
157 	short *data = buf;
158 	/* If the device won't clear it has probably
159 	* been hit by a serious failure - but we'll
160 	* try to return a sense key even so */
161 	if (!gdrom_wait_clrbusy()) {
162 		gdrom_getsense(NULL);
163 		return;
164 	}
165 	__raw_writeb(GDROM_COM_IDDEV, GDROM_STATUSCOMMAND_REG);
166 	if (!gdrom_wait_busy_sleeps()) {
167 		gdrom_getsense(NULL);
168 		return;
169 	}
170 	/* now read in the data */
171 	for (c = 0; c < 40; c++)
172 		data[c] = __raw_readw(GDROM_DATA_REG);
173 }
174 
175 static void gdrom_spicommand(void *spi_string, int buflen)
176 {
177 	short *cmd = spi_string;
178 	unsigned long timeout;
179 
180 	/* ensure IRQ_WAIT is set */
181 	__raw_writeb(0x08, GDROM_ALTSTATUS_REG);
182 	/* specify how many bytes we expect back */
183 	__raw_writeb(buflen & 0xFF, GDROM_BCL_REG);
184 	__raw_writeb((buflen >> 8) & 0xFF, GDROM_BCH_REG);
185 	/* other parameters */
186 	__raw_writeb(0, GDROM_INTSEC_REG);
187 	__raw_writeb(0, GDROM_SECNUM_REG);
188 	__raw_writeb(0, GDROM_ERROR_REG);
189 	/* Wait until we can go */
190 	if (!gdrom_wait_clrbusy()) {
191 		gdrom_getsense(NULL);
192 		return;
193 	}
194 	timeout = jiffies + GDROM_DEFAULT_TIMEOUT;
195 	__raw_writeb(GDROM_COM_PACKET, GDROM_STATUSCOMMAND_REG);
196 	while (!gdrom_data_request() && time_before(jiffies, timeout))
197 		cpu_relax();
198 	if (!time_before(jiffies, timeout + 1)) {
199 		gdrom_getsense(NULL);
200 		return;
201 	}
202 	outsw(GDROM_DATA_REG, cmd, 6);
203 }
204 
205 
206 /* gdrom_command_executediagnostic:
207  * Used to probe for presence of working GDROM
208  * Restarts GDROM device and then applies standard ATA 3
209  * Execute Diagnostic Command: a return of '1' indicates device 0
210  * present and device 1 absent
211  */
212 static char gdrom_execute_diagnostic(void)
213 {
214 	gdrom_hardreset(gd.cd_info);
215 	if (!gdrom_wait_clrbusy())
216 		return 0;
217 	__raw_writeb(GDROM_COM_EXECDIAG, GDROM_STATUSCOMMAND_REG);
218 	if (!gdrom_wait_busy_sleeps())
219 		return 0;
220 	return __raw_readb(GDROM_ERROR_REG);
221 }
222 
223 /*
224  * Prepare disk command
225  * byte 0 = 0x70
226  * byte 1 = 0x1f
227  */
228 static int gdrom_preparedisk_cmd(void)
229 {
230 	struct packet_command *spin_command;
231 	spin_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
232 	if (!spin_command)
233 		return -ENOMEM;
234 	spin_command->cmd[0] = 0x70;
235 	spin_command->cmd[2] = 0x1f;
236 	spin_command->buflen = 0;
237 	gd.pending = 1;
238 	gdrom_packetcommand(gd.cd_info, spin_command);
239 	/* 60 second timeout */
240 	wait_event_interruptible_timeout(command_queue, gd.pending == 0,
241 		GDROM_DEFAULT_TIMEOUT);
242 	gd.pending = 0;
243 	kfree(spin_command);
244 	if (gd.status & 0x01) {
245 		/* log an error */
246 		gdrom_getsense(NULL);
247 		return -EIO;
248 	}
249 	return 0;
250 }
251 
252 /*
253  * Read TOC command
254  * byte 0 = 0x14
255  * byte 1 = session
256  * byte 3 = sizeof TOC >> 8  ie upper byte
257  * byte 4 = sizeof TOC & 0xff ie lower byte
258  */
259 static int gdrom_readtoc_cmd(struct gdromtoc *toc, int session)
260 {
261 	int tocsize;
262 	struct packet_command *toc_command;
263 	int err = 0;
264 
265 	toc_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
266 	if (!toc_command)
267 		return -ENOMEM;
268 	tocsize = sizeof(struct gdromtoc);
269 	toc_command->cmd[0] = 0x14;
270 	toc_command->cmd[1] = session;
271 	toc_command->cmd[3] = tocsize >> 8;
272 	toc_command->cmd[4] = tocsize & 0xff;
273 	toc_command->buflen = tocsize;
274 	if (gd.pending) {
275 		err = -EBUSY;
276 		goto cleanup_readtoc_final;
277 	}
278 	gd.pending = 1;
279 	gdrom_packetcommand(gd.cd_info, toc_command);
280 	wait_event_interruptible_timeout(command_queue, gd.pending == 0,
281 		GDROM_DEFAULT_TIMEOUT);
282 	if (gd.pending) {
283 		err = -EINVAL;
284 		goto cleanup_readtoc;
285 	}
286 	insw(GDROM_DATA_REG, toc, tocsize/2);
287 	if (gd.status & 0x01)
288 		err = -EINVAL;
289 
290 cleanup_readtoc:
291 	gd.pending = 0;
292 cleanup_readtoc_final:
293 	kfree(toc_command);
294 	return err;
295 }
296 
297 /* TOC helpers */
298 static int get_entry_lba(int track)
299 {
300 	return (cpu_to_be32(track & 0xffffff00) - GD_SESSION_OFFSET);
301 }
302 
303 static int get_entry_q_ctrl(int track)
304 {
305 	return (track & 0x000000f0) >> 4;
306 }
307 
308 static int get_entry_track(int track)
309 {
310 	return (track & 0x0000ff00) >> 8;
311 }
312 
313 static int gdrom_get_last_session(struct cdrom_device_info *cd_info,
314 	struct cdrom_multisession *ms_info)
315 {
316 	int fentry, lentry, track, data, err;
317 
318 	if (!gd.toc)
319 		return -ENOMEM;
320 
321 	/* Check if GD-ROM */
322 	err = gdrom_readtoc_cmd(gd.toc, 1);
323 	/* Not a GD-ROM so check if standard CD-ROM */
324 	if (err) {
325 		err = gdrom_readtoc_cmd(gd.toc, 0);
326 		if (err) {
327 			pr_info("Could not get CD table of contents\n");
328 			return -ENXIO;
329 		}
330 	}
331 
332 	fentry = get_entry_track(gd.toc->first);
333 	lentry = get_entry_track(gd.toc->last);
334 	/* Find the first data track */
335 	track = get_entry_track(gd.toc->last);
336 	do {
337 		data = gd.toc->entry[track - 1];
338 		if (get_entry_q_ctrl(data))
339 			break;	/* ie a real data track */
340 		track--;
341 	} while (track >= fentry);
342 
343 	if ((track > 100) || (track < get_entry_track(gd.toc->first))) {
344 		pr_info("No data on the last session of the CD\n");
345 		gdrom_getsense(NULL);
346 		return -ENXIO;
347 	}
348 
349 	ms_info->addr_format = CDROM_LBA;
350 	ms_info->addr.lba = get_entry_lba(data);
351 	ms_info->xa_flag = 1;
352 	return 0;
353 }
354 
355 static int gdrom_open(struct cdrom_device_info *cd_info, int purpose)
356 {
357 	/* spin up the disk */
358 	return gdrom_preparedisk_cmd();
359 }
360 
361 /* this function is required even if empty */
362 static void gdrom_release(struct cdrom_device_info *cd_info)
363 {
364 }
365 
366 static int gdrom_drivestatus(struct cdrom_device_info *cd_info, int ignore)
367 {
368 	/* read the sense key */
369 	char sense = __raw_readb(GDROM_ERROR_REG);
370 	sense &= 0xF0;
371 	if (sense == 0)
372 		return CDS_DISC_OK;
373 	if (sense == 0x20)
374 		return CDS_DRIVE_NOT_READY;
375 	/* default */
376 	return CDS_NO_INFO;
377 }
378 
379 static unsigned int gdrom_check_events(struct cdrom_device_info *cd_info,
380 				       unsigned int clearing, int ignore)
381 {
382 	/* check the sense key */
383 	return (__raw_readb(GDROM_ERROR_REG) & 0xF0) == 0x60 ?
384 		DISK_EVENT_MEDIA_CHANGE : 0;
385 }
386 
387 /* reset the G1 bus */
388 static int gdrom_hardreset(struct cdrom_device_info *cd_info)
389 {
390 	int count;
391 	__raw_writel(0x1fffff, GDROM_RESET_REG);
392 	for (count = 0xa0000000; count < 0xa0200000; count += 4)
393 		__raw_readl(count);
394 	return 0;
395 }
396 
397 /* keep the function looking like the universal
398  * CD Rom specification  - returning int */
399 static int gdrom_packetcommand(struct cdrom_device_info *cd_info,
400 	struct packet_command *command)
401 {
402 	gdrom_spicommand(&command->cmd, command->buflen);
403 	return 0;
404 }
405 
406 /* Get Sense SPI command
407  * From Marcus Comstedt
408  * cmd = 0x13
409  * cmd + 4 = length of returned buffer
410  * Returns 5 16 bit words
411  */
412 static int gdrom_getsense(short *bufstring)
413 {
414 	struct packet_command *sense_command;
415 	short sense[5];
416 	int sense_key;
417 	int err = -EIO;
418 
419 	sense_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
420 	if (!sense_command)
421 		return -ENOMEM;
422 	sense_command->cmd[0] = 0x13;
423 	sense_command->cmd[4] = 10;
424 	sense_command->buflen = 10;
425 	/* even if something is pending try to get
426 	* the sense key if possible */
427 	if (gd.pending && !gdrom_wait_clrbusy()) {
428 		err = -EBUSY;
429 		goto cleanup_sense_final;
430 	}
431 	gd.pending = 1;
432 	gdrom_packetcommand(gd.cd_info, sense_command);
433 	wait_event_interruptible_timeout(command_queue, gd.pending == 0,
434 		GDROM_DEFAULT_TIMEOUT);
435 	if (gd.pending)
436 		goto cleanup_sense;
437 	insw(GDROM_DATA_REG, &sense, sense_command->buflen/2);
438 	if (sense[1] & 40) {
439 		pr_info("Drive not ready - command aborted\n");
440 		goto cleanup_sense;
441 	}
442 	sense_key = sense[1] & 0x0F;
443 	if (sense_key < ARRAY_SIZE(sense_texts))
444 		pr_info("%s\n", sense_texts[sense_key].text);
445 	else
446 		pr_err("Unknown sense key: %d\n", sense_key);
447 	if (bufstring) /* return addional sense data */
448 		memcpy(bufstring, &sense[4], 2);
449 	if (sense_key < 2)
450 		err = 0;
451 
452 cleanup_sense:
453 	gd.pending = 0;
454 cleanup_sense_final:
455 	kfree(sense_command);
456 	return err;
457 }
458 
459 static int gdrom_audio_ioctl(struct cdrom_device_info *cdi, unsigned int cmd,
460 			     void *arg)
461 {
462 	return -EINVAL;
463 }
464 
465 static const struct cdrom_device_ops gdrom_ops = {
466 	.open			= gdrom_open,
467 	.release		= gdrom_release,
468 	.drive_status		= gdrom_drivestatus,
469 	.check_events		= gdrom_check_events,
470 	.get_last_session	= gdrom_get_last_session,
471 	.reset			= gdrom_hardreset,
472 	.audio_ioctl		= gdrom_audio_ioctl,
473 	.generic_packet		= cdrom_dummy_generic_packet,
474 	.capability		= CDC_MULTI_SESSION | CDC_MEDIA_CHANGED |
475 				  CDC_RESET | CDC_DRIVE_STATUS | CDC_CD_R,
476 };
477 
478 static int gdrom_bdops_open(struct block_device *bdev, fmode_t mode)
479 {
480 	int ret;
481 
482 	bdev_check_media_change(bdev);
483 
484 	mutex_lock(&gdrom_mutex);
485 	ret = cdrom_open(gd.cd_info, bdev, mode);
486 	mutex_unlock(&gdrom_mutex);
487 	return ret;
488 }
489 
490 static void gdrom_bdops_release(struct gendisk *disk, fmode_t mode)
491 {
492 	mutex_lock(&gdrom_mutex);
493 	cdrom_release(gd.cd_info, mode);
494 	mutex_unlock(&gdrom_mutex);
495 }
496 
497 static unsigned int gdrom_bdops_check_events(struct gendisk *disk,
498 					     unsigned int clearing)
499 {
500 	return cdrom_check_events(gd.cd_info, clearing);
501 }
502 
503 static int gdrom_bdops_ioctl(struct block_device *bdev, fmode_t mode,
504 	unsigned cmd, unsigned long arg)
505 {
506 	int ret;
507 
508 	mutex_lock(&gdrom_mutex);
509 	ret = cdrom_ioctl(gd.cd_info, bdev, mode, cmd, arg);
510 	mutex_unlock(&gdrom_mutex);
511 
512 	return ret;
513 }
514 
515 static const struct block_device_operations gdrom_bdops = {
516 	.owner			= THIS_MODULE,
517 	.open			= gdrom_bdops_open,
518 	.release		= gdrom_bdops_release,
519 	.check_events		= gdrom_bdops_check_events,
520 	.ioctl			= gdrom_bdops_ioctl,
521 #ifdef CONFIG_COMPAT
522 	.compat_ioctl		= blkdev_compat_ptr_ioctl,
523 #endif
524 };
525 
526 static irqreturn_t gdrom_command_interrupt(int irq, void *dev_id)
527 {
528 	gd.status = __raw_readb(GDROM_STATUSCOMMAND_REG);
529 	if (gd.pending != 1)
530 		return IRQ_HANDLED;
531 	gd.pending = 0;
532 	wake_up_interruptible(&command_queue);
533 	return IRQ_HANDLED;
534 }
535 
536 static irqreturn_t gdrom_dma_interrupt(int irq, void *dev_id)
537 {
538 	gd.status = __raw_readb(GDROM_STATUSCOMMAND_REG);
539 	if (gd.transfer != 1)
540 		return IRQ_HANDLED;
541 	gd.transfer = 0;
542 	wake_up_interruptible(&request_queue);
543 	return IRQ_HANDLED;
544 }
545 
546 static int gdrom_set_interrupt_handlers(void)
547 {
548 	int err;
549 
550 	err = request_irq(HW_EVENT_GDROM_CMD, gdrom_command_interrupt,
551 		0, "gdrom_command", &gd);
552 	if (err)
553 		return err;
554 	err = request_irq(HW_EVENT_GDROM_DMA, gdrom_dma_interrupt,
555 		0, "gdrom_dma", &gd);
556 	if (err)
557 		free_irq(HW_EVENT_GDROM_CMD, &gd);
558 	return err;
559 }
560 
561 /* Implement DMA read using SPI command
562  * 0 -> 0x30
563  * 1 -> mode
564  * 2 -> block >> 16
565  * 3 -> block >> 8
566  * 4 -> block
567  * 8 -> sectors >> 16
568  * 9 -> sectors >> 8
569  * 10 -> sectors
570  */
571 static blk_status_t gdrom_readdisk_dma(struct request *req)
572 {
573 	int block, block_cnt;
574 	blk_status_t err;
575 	struct packet_command *read_command;
576 	unsigned long timeout;
577 
578 	read_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
579 	if (!read_command)
580 		return BLK_STS_RESOURCE;
581 
582 	read_command->cmd[0] = 0x30;
583 	read_command->cmd[1] = 0x20;
584 	block = blk_rq_pos(req)/GD_TO_BLK + GD_SESSION_OFFSET;
585 	block_cnt = blk_rq_sectors(req)/GD_TO_BLK;
586 	__raw_writel(page_to_phys(bio_page(req->bio)) + bio_offset(req->bio),
587 			GDROM_DMA_STARTADDR_REG);
588 	__raw_writel(block_cnt * GDROM_HARD_SECTOR, GDROM_DMA_LENGTH_REG);
589 	__raw_writel(1, GDROM_DMA_DIRECTION_REG);
590 	__raw_writel(1, GDROM_DMA_ENABLE_REG);
591 	read_command->cmd[2] = (block >> 16) & 0xFF;
592 	read_command->cmd[3] = (block >> 8) & 0xFF;
593 	read_command->cmd[4] = block & 0xFF;
594 	read_command->cmd[8] = (block_cnt >> 16) & 0xFF;
595 	read_command->cmd[9] = (block_cnt >> 8) & 0xFF;
596 	read_command->cmd[10] = block_cnt & 0xFF;
597 	/* set for DMA */
598 	__raw_writeb(1, GDROM_ERROR_REG);
599 	/* other registers */
600 	__raw_writeb(0, GDROM_SECNUM_REG);
601 	__raw_writeb(0, GDROM_BCL_REG);
602 	__raw_writeb(0, GDROM_BCH_REG);
603 	__raw_writeb(0, GDROM_DSEL_REG);
604 	__raw_writeb(0, GDROM_INTSEC_REG);
605 	/* Wait for registers to reset after any previous activity */
606 	timeout = jiffies + HZ / 2;
607 	while (gdrom_is_busy() && time_before(jiffies, timeout))
608 		cpu_relax();
609 	__raw_writeb(GDROM_COM_PACKET, GDROM_STATUSCOMMAND_REG);
610 	timeout = jiffies + HZ / 2;
611 	/* Wait for packet command to finish */
612 	while (gdrom_is_busy() && time_before(jiffies, timeout))
613 		cpu_relax();
614 	gd.pending = 1;
615 	gd.transfer = 1;
616 	outsw(GDROM_DATA_REG, &read_command->cmd, 6);
617 	timeout = jiffies + HZ / 2;
618 	/* Wait for any pending DMA to finish */
619 	while (__raw_readb(GDROM_DMA_STATUS_REG) &&
620 		time_before(jiffies, timeout))
621 		cpu_relax();
622 	/* start transfer */
623 	__raw_writeb(1, GDROM_DMA_STATUS_REG);
624 	wait_event_interruptible_timeout(request_queue,
625 		gd.transfer == 0, GDROM_DEFAULT_TIMEOUT);
626 	err = gd.transfer ? BLK_STS_IOERR : BLK_STS_OK;
627 	gd.transfer = 0;
628 	gd.pending = 0;
629 
630 	blk_mq_end_request(req, err);
631 	kfree(read_command);
632 	return BLK_STS_OK;
633 }
634 
635 static blk_status_t gdrom_queue_rq(struct blk_mq_hw_ctx *hctx,
636 				   const struct blk_mq_queue_data *bd)
637 {
638 	blk_mq_start_request(bd->rq);
639 
640 	switch (req_op(bd->rq)) {
641 	case REQ_OP_READ:
642 		return gdrom_readdisk_dma(bd->rq);
643 	case REQ_OP_WRITE:
644 		pr_notice("Read only device - write request ignored\n");
645 		return BLK_STS_IOERR;
646 	default:
647 		printk(KERN_DEBUG "gdrom: Non-fs request ignored\n");
648 		return BLK_STS_IOERR;
649 	}
650 }
651 
652 /* Print string identifying GD ROM device */
653 static int gdrom_outputversion(void)
654 {
655 	struct gdrom_id *id;
656 	char *model_name, *manuf_name, *firmw_ver;
657 	int err = -ENOMEM;
658 
659 	/* query device ID */
660 	id = kzalloc(sizeof(struct gdrom_id), GFP_KERNEL);
661 	if (!id)
662 		return err;
663 	gdrom_identifydevice(id);
664 	model_name = kstrndup(id->modname, 16, GFP_KERNEL);
665 	if (!model_name)
666 		goto free_id;
667 	manuf_name = kstrndup(id->mname, 16, GFP_KERNEL);
668 	if (!manuf_name)
669 		goto free_model_name;
670 	firmw_ver = kstrndup(id->firmver, 16, GFP_KERNEL);
671 	if (!firmw_ver)
672 		goto free_manuf_name;
673 	pr_info("%s from %s with firmware %s\n",
674 		model_name, manuf_name, firmw_ver);
675 	err = 0;
676 	kfree(firmw_ver);
677 free_manuf_name:
678 	kfree(manuf_name);
679 free_model_name:
680 	kfree(model_name);
681 free_id:
682 	kfree(id);
683 	return err;
684 }
685 
686 /* set the default mode for DMA transfer */
687 static int gdrom_init_dma_mode(void)
688 {
689 	__raw_writeb(0x13, GDROM_ERROR_REG);
690 	__raw_writeb(0x22, GDROM_INTSEC_REG);
691 	if (!gdrom_wait_clrbusy())
692 		return -EBUSY;
693 	__raw_writeb(0xEF, GDROM_STATUSCOMMAND_REG);
694 	if (!gdrom_wait_busy_sleeps())
695 		return -EBUSY;
696 	/* Memory protection setting for GDROM DMA
697 	* Bits 31 - 16 security: 0x8843
698 	* Bits 15 and 7 reserved (0)
699 	* Bits 14 - 8 start of transfer range in 1 MB blocks OR'ed with 0x80
700 	* Bits 6 - 0 end of transfer range in 1 MB blocks OR'ed with 0x80
701 	* (0x40 | 0x80) = start range at 0x0C000000
702 	* (0x7F | 0x80) = end range at 0x0FFFFFFF */
703 	__raw_writel(0x8843407F, GDROM_DMA_ACCESS_CTRL_REG);
704 	__raw_writel(9, GDROM_DMA_WAIT_REG); /* DMA word setting */
705 	return 0;
706 }
707 
708 static void probe_gdrom_setupcd(void)
709 {
710 	gd.cd_info->ops = &gdrom_ops;
711 	gd.cd_info->capacity = 1;
712 	strcpy(gd.cd_info->name, GDROM_DEV_NAME);
713 	gd.cd_info->mask = CDC_CLOSE_TRAY|CDC_OPEN_TRAY|CDC_LOCK|
714 		CDC_SELECT_DISC;
715 }
716 
717 static void probe_gdrom_setupdisk(void)
718 {
719 	gd.disk->major = gdrom_major;
720 	gd.disk->first_minor = 1;
721 	gd.disk->minors = 1;
722 	strcpy(gd.disk->disk_name, GDROM_DEV_NAME);
723 }
724 
725 static int probe_gdrom_setupqueue(void)
726 {
727 	blk_queue_logical_block_size(gd.gdrom_rq, GDROM_HARD_SECTOR);
728 	/* using DMA so memory will need to be contiguous */
729 	blk_queue_max_segments(gd.gdrom_rq, 1);
730 	/* set a large max size to get most from DMA */
731 	blk_queue_max_segment_size(gd.gdrom_rq, 0x40000);
732 	gd.disk->queue = gd.gdrom_rq;
733 	return gdrom_init_dma_mode();
734 }
735 
736 static const struct blk_mq_ops gdrom_mq_ops = {
737 	.queue_rq	= gdrom_queue_rq,
738 };
739 
740 /*
741  * register this as a block device and as compliant with the
742  * universal CD Rom driver interface
743  */
744 static int probe_gdrom(struct platform_device *devptr)
745 {
746 	int err;
747 
748 	/*
749 	 * Ensure our "one" device is initialized properly in case of previous
750 	 * usages of it
751 	 */
752 	memset(&gd, 0, sizeof(gd));
753 
754 	/* Start the device */
755 	if (gdrom_execute_diagnostic() != 1) {
756 		pr_warn("ATA Probe for GDROM failed\n");
757 		return -ENODEV;
758 	}
759 	/* Print out firmware ID */
760 	if (gdrom_outputversion())
761 		return -ENOMEM;
762 	/* Register GDROM */
763 	gdrom_major = register_blkdev(0, GDROM_DEV_NAME);
764 	if (gdrom_major <= 0)
765 		return gdrom_major;
766 	pr_info("Registered with major number %d\n",
767 		gdrom_major);
768 	/* Specify basic properties of drive */
769 	gd.cd_info = kzalloc(sizeof(struct cdrom_device_info), GFP_KERNEL);
770 	if (!gd.cd_info) {
771 		err = -ENOMEM;
772 		goto probe_fail_no_mem;
773 	}
774 	probe_gdrom_setupcd();
775 
776 	err = blk_mq_alloc_sq_tag_set(&gd.tag_set, &gdrom_mq_ops, 1,
777 				BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_BLOCKING);
778 	if (err)
779 		goto probe_fail_free_cd_info;
780 
781 	gd.disk = blk_mq_alloc_disk(&gd.tag_set, NULL);
782 	if (IS_ERR(gd.disk)) {
783 		err = PTR_ERR(gd.disk);
784 		goto probe_fail_free_tag_set;
785 	}
786 	gd.gdrom_rq = gd.disk->queue;
787 	probe_gdrom_setupdisk();
788 	if (register_cdrom(gd.disk, gd.cd_info)) {
789 		err = -ENODEV;
790 		goto probe_fail_cleanup_disk;
791 	}
792 	gd.disk->fops = &gdrom_bdops;
793 	gd.disk->events = DISK_EVENT_MEDIA_CHANGE;
794 	/* latch on to the interrupt */
795 	err = gdrom_set_interrupt_handlers();
796 	if (err)
797 		goto probe_fail_cleanup_disk;
798 
799 	err = probe_gdrom_setupqueue();
800 	if (err)
801 		goto probe_fail_free_irqs;
802 
803 	gd.toc = kzalloc(sizeof(struct gdromtoc), GFP_KERNEL);
804 	if (!gd.toc) {
805 		err = -ENOMEM;
806 		goto probe_fail_free_irqs;
807 	}
808 	add_disk(gd.disk);
809 	return 0;
810 
811 probe_fail_free_irqs:
812 	free_irq(HW_EVENT_GDROM_DMA, &gd);
813 	free_irq(HW_EVENT_GDROM_CMD, &gd);
814 probe_fail_cleanup_disk:
815 	blk_cleanup_disk(gd.disk);
816 probe_fail_free_tag_set:
817 	blk_mq_free_tag_set(&gd.tag_set);
818 probe_fail_free_cd_info:
819 	kfree(gd.cd_info);
820 probe_fail_no_mem:
821 	unregister_blkdev(gdrom_major, GDROM_DEV_NAME);
822 	gdrom_major = 0;
823 	pr_warn("Probe failed - error is 0x%X\n", err);
824 	return err;
825 }
826 
827 static int remove_gdrom(struct platform_device *devptr)
828 {
829 	blk_cleanup_queue(gd.gdrom_rq);
830 	blk_mq_free_tag_set(&gd.tag_set);
831 	free_irq(HW_EVENT_GDROM_CMD, &gd);
832 	free_irq(HW_EVENT_GDROM_DMA, &gd);
833 	del_gendisk(gd.disk);
834 	if (gdrom_major)
835 		unregister_blkdev(gdrom_major, GDROM_DEV_NAME);
836 	unregister_cdrom(gd.cd_info);
837 	kfree(gd.cd_info);
838 	kfree(gd.toc);
839 
840 	return 0;
841 }
842 
843 static struct platform_driver gdrom_driver = {
844 	.probe = probe_gdrom,
845 	.remove = remove_gdrom,
846 	.driver = {
847 			.name = GDROM_DEV_NAME,
848 	},
849 };
850 
851 static int __init init_gdrom(void)
852 {
853 	int rc;
854 
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 }
871 
872 module_init(init_gdrom);
873 module_exit(exit_gdrom);
874 MODULE_AUTHOR("Adrian McMenamin <adrian@mcmen.demon.co.uk>");
875 MODULE_DESCRIPTION("SEGA Dreamcast GD-ROM Driver");
876 MODULE_LICENSE("GPL");
877