xref: /openbmc/linux/drivers/cdrom/gdrom.c (revision 0a94608f)
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/bio.h>
19 #include <linux/blk-mq.h>
20 #include <linux/interrupt.h>
21 #include <linux/device.h>
22 #include <linux/mutex.h>
23 #include <linux/wait.h>
24 #include <linux/platform_device.h>
25 #include <scsi/scsi.h>
26 #include <asm/io.h>
27 #include <asm/dma.h>
28 #include <asm/delay.h>
29 #include <mach/dma.h>
30 #include <mach/sysasic.h>
31 
32 #define GDROM_DEV_NAME "gdrom"
33 #define GD_SESSION_OFFSET 150
34 
35 /* GD Rom commands */
36 #define GDROM_COM_SOFTRESET 0x08
37 #define GDROM_COM_EXECDIAG 0x90
38 #define GDROM_COM_PACKET 0xA0
39 #define GDROM_COM_IDDEV 0xA1
40 
41 /* GD Rom registers */
42 #define GDROM_BASE_REG			0xA05F7000
43 #define GDROM_ALTSTATUS_REG		(GDROM_BASE_REG + 0x18)
44 #define GDROM_DATA_REG			(GDROM_BASE_REG + 0x80)
45 #define GDROM_ERROR_REG		(GDROM_BASE_REG + 0x84)
46 #define GDROM_INTSEC_REG		(GDROM_BASE_REG + 0x88)
47 #define GDROM_SECNUM_REG		(GDROM_BASE_REG + 0x8C)
48 #define GDROM_BCL_REG			(GDROM_BASE_REG + 0x90)
49 #define GDROM_BCH_REG			(GDROM_BASE_REG + 0x94)
50 #define GDROM_DSEL_REG			(GDROM_BASE_REG + 0x98)
51 #define GDROM_STATUSCOMMAND_REG	(GDROM_BASE_REG + 0x9C)
52 #define GDROM_RESET_REG		(GDROM_BASE_REG + 0x4E4)
53 
54 #define GDROM_DMA_STARTADDR_REG	(GDROM_BASE_REG + 0x404)
55 #define GDROM_DMA_LENGTH_REG		(GDROM_BASE_REG + 0x408)
56 #define GDROM_DMA_DIRECTION_REG	(GDROM_BASE_REG + 0x40C)
57 #define GDROM_DMA_ENABLE_REG		(GDROM_BASE_REG + 0x414)
58 #define GDROM_DMA_STATUS_REG		(GDROM_BASE_REG + 0x418)
59 #define GDROM_DMA_WAIT_REG		(GDROM_BASE_REG + 0x4A0)
60 #define GDROM_DMA_ACCESS_CTRL_REG	(GDROM_BASE_REG + 0x4B8)
61 
62 #define GDROM_HARD_SECTOR	2048
63 #define BLOCK_LAYER_SECTOR	512
64 #define GD_TO_BLK		4
65 
66 #define GDROM_DEFAULT_TIMEOUT	(HZ * 7)
67 
68 static DEFINE_MUTEX(gdrom_mutex);
69 static const struct {
70 	int sense_key;
71 	const char * const text;
72 } sense_texts[] = {
73 	{NO_SENSE, "OK"},
74 	{RECOVERED_ERROR, "Recovered from error"},
75 	{NOT_READY, "Device not ready"},
76 	{MEDIUM_ERROR, "Disk not ready"},
77 	{HARDWARE_ERROR, "Hardware error"},
78 	{ILLEGAL_REQUEST, "Command has failed"},
79 	{UNIT_ATTENTION, "Device needs attention - disk may have been changed"},
80 	{DATA_PROTECT, "Data protection error"},
81 	{ABORTED_COMMAND, "Command aborted"},
82 };
83 
84 static struct platform_device *pd;
85 static int gdrom_major;
86 static DECLARE_WAIT_QUEUE_HEAD(command_queue);
87 static DECLARE_WAIT_QUEUE_HEAD(request_queue);
88 
89 struct gdromtoc {
90 	unsigned int entry[99];
91 	unsigned int first, last;
92 	unsigned int leadout;
93 };
94 
95 static struct gdrom_unit {
96 	struct gendisk *disk;
97 	struct cdrom_device_info *cd_info;
98 	int status;
99 	int pending;
100 	int transfer;
101 	char disk_type;
102 	struct gdromtoc *toc;
103 	struct request_queue *gdrom_rq;
104 	struct blk_mq_tag_set tag_set;
105 } gd;
106 
107 struct gdrom_id {
108 	char mid;
109 	char modid;
110 	char verid;
111 	char padA[13];
112 	char mname[16];
113 	char modname[16];
114 	char firmver[16];
115 	char padB[16];
116 };
117 
118 static int gdrom_getsense(short *bufstring);
119 static int gdrom_packetcommand(struct cdrom_device_info *cd_info,
120 	struct packet_command *command);
121 static int gdrom_hardreset(struct cdrom_device_info *cd_info);
122 
123 static bool gdrom_is_busy(void)
124 {
125 	return (__raw_readb(GDROM_ALTSTATUS_REG) & 0x80) != 0;
126 }
127 
128 static bool gdrom_data_request(void)
129 {
130 	return (__raw_readb(GDROM_ALTSTATUS_REG) & 0x88) == 8;
131 }
132 
133 static bool gdrom_wait_clrbusy(void)
134 {
135 	unsigned long timeout = jiffies + GDROM_DEFAULT_TIMEOUT;
136 	while ((__raw_readb(GDROM_ALTSTATUS_REG) & 0x80) &&
137 		(time_before(jiffies, timeout)))
138 		cpu_relax();
139 	return time_before(jiffies, timeout + 1);
140 }
141 
142 static bool gdrom_wait_busy_sleeps(void)
143 {
144 	unsigned long timeout;
145 	/* Wait to get busy first */
146 	timeout = jiffies + GDROM_DEFAULT_TIMEOUT;
147 	while (!gdrom_is_busy() && time_before(jiffies, timeout))
148 		cpu_relax();
149 	/* Now wait for busy to clear */
150 	return gdrom_wait_clrbusy();
151 }
152 
153 static void gdrom_identifydevice(void *buf)
154 {
155 	int c;
156 	short *data = buf;
157 	/* If the device won't clear it has probably
158 	* been hit by a serious failure - but we'll
159 	* try to return a sense key even so */
160 	if (!gdrom_wait_clrbusy()) {
161 		gdrom_getsense(NULL);
162 		return;
163 	}
164 	__raw_writeb(GDROM_COM_IDDEV, GDROM_STATUSCOMMAND_REG);
165 	if (!gdrom_wait_busy_sleeps()) {
166 		gdrom_getsense(NULL);
167 		return;
168 	}
169 	/* now read in the data */
170 	for (c = 0; c < 40; c++)
171 		data[c] = __raw_readw(GDROM_DATA_REG);
172 }
173 
174 static void gdrom_spicommand(void *spi_string, int buflen)
175 {
176 	short *cmd = spi_string;
177 	unsigned long timeout;
178 
179 	/* ensure IRQ_WAIT is set */
180 	__raw_writeb(0x08, GDROM_ALTSTATUS_REG);
181 	/* specify how many bytes we expect back */
182 	__raw_writeb(buflen & 0xFF, GDROM_BCL_REG);
183 	__raw_writeb((buflen >> 8) & 0xFF, GDROM_BCH_REG);
184 	/* other parameters */
185 	__raw_writeb(0, GDROM_INTSEC_REG);
186 	__raw_writeb(0, GDROM_SECNUM_REG);
187 	__raw_writeb(0, GDROM_ERROR_REG);
188 	/* Wait until we can go */
189 	if (!gdrom_wait_clrbusy()) {
190 		gdrom_getsense(NULL);
191 		return;
192 	}
193 	timeout = jiffies + GDROM_DEFAULT_TIMEOUT;
194 	__raw_writeb(GDROM_COM_PACKET, GDROM_STATUSCOMMAND_REG);
195 	while (!gdrom_data_request() && time_before(jiffies, timeout))
196 		cpu_relax();
197 	if (!time_before(jiffies, timeout + 1)) {
198 		gdrom_getsense(NULL);
199 		return;
200 	}
201 	outsw(GDROM_DATA_REG, cmd, 6);
202 }
203 
204 
205 /* gdrom_command_executediagnostic:
206  * Used to probe for presence of working GDROM
207  * Restarts GDROM device and then applies standard ATA 3
208  * Execute Diagnostic Command: a return of '1' indicates device 0
209  * present and device 1 absent
210  */
211 static char gdrom_execute_diagnostic(void)
212 {
213 	gdrom_hardreset(gd.cd_info);
214 	if (!gdrom_wait_clrbusy())
215 		return 0;
216 	__raw_writeb(GDROM_COM_EXECDIAG, GDROM_STATUSCOMMAND_REG);
217 	if (!gdrom_wait_busy_sleeps())
218 		return 0;
219 	return __raw_readb(GDROM_ERROR_REG);
220 }
221 
222 /*
223  * Prepare disk command
224  * byte 0 = 0x70
225  * byte 1 = 0x1f
226  */
227 static int gdrom_preparedisk_cmd(void)
228 {
229 	struct packet_command *spin_command;
230 	spin_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
231 	if (!spin_command)
232 		return -ENOMEM;
233 	spin_command->cmd[0] = 0x70;
234 	spin_command->cmd[2] = 0x1f;
235 	spin_command->buflen = 0;
236 	gd.pending = 1;
237 	gdrom_packetcommand(gd.cd_info, spin_command);
238 	/* 60 second timeout */
239 	wait_event_interruptible_timeout(command_queue, gd.pending == 0,
240 		GDROM_DEFAULT_TIMEOUT);
241 	gd.pending = 0;
242 	kfree(spin_command);
243 	if (gd.status & 0x01) {
244 		/* log an error */
245 		gdrom_getsense(NULL);
246 		return -EIO;
247 	}
248 	return 0;
249 }
250 
251 /*
252  * Read TOC command
253  * byte 0 = 0x14
254  * byte 1 = session
255  * byte 3 = sizeof TOC >> 8  ie upper byte
256  * byte 4 = sizeof TOC & 0xff ie lower byte
257  */
258 static int gdrom_readtoc_cmd(struct gdromtoc *toc, int session)
259 {
260 	int tocsize;
261 	struct packet_command *toc_command;
262 	int err = 0;
263 
264 	toc_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
265 	if (!toc_command)
266 		return -ENOMEM;
267 	tocsize = sizeof(struct gdromtoc);
268 	toc_command->cmd[0] = 0x14;
269 	toc_command->cmd[1] = session;
270 	toc_command->cmd[3] = tocsize >> 8;
271 	toc_command->cmd[4] = tocsize & 0xff;
272 	toc_command->buflen = tocsize;
273 	if (gd.pending) {
274 		err = -EBUSY;
275 		goto cleanup_readtoc_final;
276 	}
277 	gd.pending = 1;
278 	gdrom_packetcommand(gd.cd_info, toc_command);
279 	wait_event_interruptible_timeout(command_queue, gd.pending == 0,
280 		GDROM_DEFAULT_TIMEOUT);
281 	if (gd.pending) {
282 		err = -EINVAL;
283 		goto cleanup_readtoc;
284 	}
285 	insw(GDROM_DATA_REG, toc, tocsize/2);
286 	if (gd.status & 0x01)
287 		err = -EINVAL;
288 
289 cleanup_readtoc:
290 	gd.pending = 0;
291 cleanup_readtoc_final:
292 	kfree(toc_command);
293 	return err;
294 }
295 
296 /* TOC helpers */
297 static int get_entry_lba(int track)
298 {
299 	return (cpu_to_be32(track & 0xffffff00) - GD_SESSION_OFFSET);
300 }
301 
302 static int get_entry_q_ctrl(int track)
303 {
304 	return (track & 0x000000f0) >> 4;
305 }
306 
307 static int get_entry_track(int track)
308 {
309 	return (track & 0x0000ff00) >> 8;
310 }
311 
312 static int gdrom_get_last_session(struct cdrom_device_info *cd_info,
313 	struct cdrom_multisession *ms_info)
314 {
315 	int fentry, lentry, track, data, err;
316 
317 	if (!gd.toc)
318 		return -ENOMEM;
319 
320 	/* Check if GD-ROM */
321 	err = gdrom_readtoc_cmd(gd.toc, 1);
322 	/* Not a GD-ROM so check if standard CD-ROM */
323 	if (err) {
324 		err = gdrom_readtoc_cmd(gd.toc, 0);
325 		if (err) {
326 			pr_info("Could not get CD table of contents\n");
327 			return -ENXIO;
328 		}
329 	}
330 
331 	fentry = get_entry_track(gd.toc->first);
332 	lentry = get_entry_track(gd.toc->last);
333 	/* Find the first data track */
334 	track = get_entry_track(gd.toc->last);
335 	do {
336 		data = gd.toc->entry[track - 1];
337 		if (get_entry_q_ctrl(data))
338 			break;	/* ie a real data track */
339 		track--;
340 	} while (track >= fentry);
341 
342 	if ((track > 100) || (track < get_entry_track(gd.toc->first))) {
343 		pr_info("No data on the last session of the CD\n");
344 		gdrom_getsense(NULL);
345 		return -ENXIO;
346 	}
347 
348 	ms_info->addr_format = CDROM_LBA;
349 	ms_info->addr.lba = get_entry_lba(data);
350 	ms_info->xa_flag = 1;
351 	return 0;
352 }
353 
354 static int gdrom_open(struct cdrom_device_info *cd_info, int purpose)
355 {
356 	/* spin up the disk */
357 	return gdrom_preparedisk_cmd();
358 }
359 
360 /* this function is required even if empty */
361 static void gdrom_release(struct cdrom_device_info *cd_info)
362 {
363 }
364 
365 static int gdrom_drivestatus(struct cdrom_device_info *cd_info, int ignore)
366 {
367 	/* read the sense key */
368 	char sense = __raw_readb(GDROM_ERROR_REG);
369 	sense &= 0xF0;
370 	if (sense == 0)
371 		return CDS_DISC_OK;
372 	if (sense == 0x20)
373 		return CDS_DRIVE_NOT_READY;
374 	/* default */
375 	return CDS_NO_INFO;
376 }
377 
378 static unsigned int gdrom_check_events(struct cdrom_device_info *cd_info,
379 				       unsigned int clearing, int ignore)
380 {
381 	/* check the sense key */
382 	return (__raw_readb(GDROM_ERROR_REG) & 0xF0) == 0x60 ?
383 		DISK_EVENT_MEDIA_CHANGE : 0;
384 }
385 
386 /* reset the G1 bus */
387 static int gdrom_hardreset(struct cdrom_device_info *cd_info)
388 {
389 	int count;
390 	__raw_writel(0x1fffff, GDROM_RESET_REG);
391 	for (count = 0xa0000000; count < 0xa0200000; count += 4)
392 		__raw_readl(count);
393 	return 0;
394 }
395 
396 /* keep the function looking like the universal
397  * CD Rom specification  - returning int */
398 static int gdrom_packetcommand(struct cdrom_device_info *cd_info,
399 	struct packet_command *command)
400 {
401 	gdrom_spicommand(&command->cmd, command->buflen);
402 	return 0;
403 }
404 
405 /* Get Sense SPI command
406  * From Marcus Comstedt
407  * cmd = 0x13
408  * cmd + 4 = length of returned buffer
409  * Returns 5 16 bit words
410  */
411 static int gdrom_getsense(short *bufstring)
412 {
413 	struct packet_command *sense_command;
414 	short sense[5];
415 	int sense_key;
416 	int err = -EIO;
417 
418 	sense_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
419 	if (!sense_command)
420 		return -ENOMEM;
421 	sense_command->cmd[0] = 0x13;
422 	sense_command->cmd[4] = 10;
423 	sense_command->buflen = 10;
424 	/* even if something is pending try to get
425 	* the sense key if possible */
426 	if (gd.pending && !gdrom_wait_clrbusy()) {
427 		err = -EBUSY;
428 		goto cleanup_sense_final;
429 	}
430 	gd.pending = 1;
431 	gdrom_packetcommand(gd.cd_info, sense_command);
432 	wait_event_interruptible_timeout(command_queue, gd.pending == 0,
433 		GDROM_DEFAULT_TIMEOUT);
434 	if (gd.pending)
435 		goto cleanup_sense;
436 	insw(GDROM_DATA_REG, &sense, sense_command->buflen/2);
437 	if (sense[1] & 40) {
438 		pr_info("Drive not ready - command aborted\n");
439 		goto cleanup_sense;
440 	}
441 	sense_key = sense[1] & 0x0F;
442 	if (sense_key < ARRAY_SIZE(sense_texts))
443 		pr_info("%s\n", sense_texts[sense_key].text);
444 	else
445 		pr_err("Unknown sense key: %d\n", sense_key);
446 	if (bufstring) /* return addional sense data */
447 		memcpy(bufstring, &sense[4], 2);
448 	if (sense_key < 2)
449 		err = 0;
450 
451 cleanup_sense:
452 	gd.pending = 0;
453 cleanup_sense_final:
454 	kfree(sense_command);
455 	return err;
456 }
457 
458 static int gdrom_audio_ioctl(struct cdrom_device_info *cdi, unsigned int cmd,
459 			     void *arg)
460 {
461 	return -EINVAL;
462 }
463 
464 static const struct cdrom_device_ops gdrom_ops = {
465 	.open			= gdrom_open,
466 	.release		= gdrom_release,
467 	.drive_status		= gdrom_drivestatus,
468 	.check_events		= gdrom_check_events,
469 	.get_last_session	= gdrom_get_last_session,
470 	.reset			= gdrom_hardreset,
471 	.audio_ioctl		= gdrom_audio_ioctl,
472 	.generic_packet		= cdrom_dummy_generic_packet,
473 	.capability		= CDC_MULTI_SESSION | CDC_MEDIA_CHANGED |
474 				  CDC_RESET | CDC_DRIVE_STATUS | CDC_CD_R,
475 };
476 
477 static int gdrom_bdops_open(struct block_device *bdev, fmode_t mode)
478 {
479 	int ret;
480 
481 	bdev_check_media_change(bdev);
482 
483 	mutex_lock(&gdrom_mutex);
484 	ret = cdrom_open(gd.cd_info, bdev, mode);
485 	mutex_unlock(&gdrom_mutex);
486 	return ret;
487 }
488 
489 static void gdrom_bdops_release(struct gendisk *disk, fmode_t mode)
490 {
491 	mutex_lock(&gdrom_mutex);
492 	cdrom_release(gd.cd_info, mode);
493 	mutex_unlock(&gdrom_mutex);
494 }
495 
496 static unsigned int gdrom_bdops_check_events(struct gendisk *disk,
497 					     unsigned int clearing)
498 {
499 	return cdrom_check_events(gd.cd_info, clearing);
500 }
501 
502 static int gdrom_bdops_ioctl(struct block_device *bdev, fmode_t mode,
503 	unsigned cmd, unsigned long arg)
504 {
505 	int ret;
506 
507 	mutex_lock(&gdrom_mutex);
508 	ret = cdrom_ioctl(gd.cd_info, bdev, mode, cmd, arg);
509 	mutex_unlock(&gdrom_mutex);
510 
511 	return ret;
512 }
513 
514 static const struct block_device_operations gdrom_bdops = {
515 	.owner			= THIS_MODULE,
516 	.open			= gdrom_bdops_open,
517 	.release		= gdrom_bdops_release,
518 	.check_events		= gdrom_bdops_check_events,
519 	.ioctl			= gdrom_bdops_ioctl,
520 #ifdef CONFIG_COMPAT
521 	.compat_ioctl		= blkdev_compat_ptr_ioctl,
522 #endif
523 };
524 
525 static irqreturn_t gdrom_command_interrupt(int irq, void *dev_id)
526 {
527 	gd.status = __raw_readb(GDROM_STATUSCOMMAND_REG);
528 	if (gd.pending != 1)
529 		return IRQ_HANDLED;
530 	gd.pending = 0;
531 	wake_up_interruptible(&command_queue);
532 	return IRQ_HANDLED;
533 }
534 
535 static irqreturn_t gdrom_dma_interrupt(int irq, void *dev_id)
536 {
537 	gd.status = __raw_readb(GDROM_STATUSCOMMAND_REG);
538 	if (gd.transfer != 1)
539 		return IRQ_HANDLED;
540 	gd.transfer = 0;
541 	wake_up_interruptible(&request_queue);
542 	return IRQ_HANDLED;
543 }
544 
545 static int gdrom_set_interrupt_handlers(void)
546 {
547 	int err;
548 
549 	err = request_irq(HW_EVENT_GDROM_CMD, gdrom_command_interrupt,
550 		0, "gdrom_command", &gd);
551 	if (err)
552 		return err;
553 	err = request_irq(HW_EVENT_GDROM_DMA, gdrom_dma_interrupt,
554 		0, "gdrom_dma", &gd);
555 	if (err)
556 		free_irq(HW_EVENT_GDROM_CMD, &gd);
557 	return err;
558 }
559 
560 /* Implement DMA read using SPI command
561  * 0 -> 0x30
562  * 1 -> mode
563  * 2 -> block >> 16
564  * 3 -> block >> 8
565  * 4 -> block
566  * 8 -> sectors >> 16
567  * 9 -> sectors >> 8
568  * 10 -> sectors
569  */
570 static blk_status_t gdrom_readdisk_dma(struct request *req)
571 {
572 	int block, block_cnt;
573 	blk_status_t err;
574 	struct packet_command *read_command;
575 	unsigned long timeout;
576 
577 	read_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
578 	if (!read_command)
579 		return BLK_STS_RESOURCE;
580 
581 	read_command->cmd[0] = 0x30;
582 	read_command->cmd[1] = 0x20;
583 	block = blk_rq_pos(req)/GD_TO_BLK + GD_SESSION_OFFSET;
584 	block_cnt = blk_rq_sectors(req)/GD_TO_BLK;
585 	__raw_writel(page_to_phys(bio_page(req->bio)) + bio_offset(req->bio),
586 			GDROM_DMA_STARTADDR_REG);
587 	__raw_writel(block_cnt * GDROM_HARD_SECTOR, GDROM_DMA_LENGTH_REG);
588 	__raw_writel(1, GDROM_DMA_DIRECTION_REG);
589 	__raw_writel(1, GDROM_DMA_ENABLE_REG);
590 	read_command->cmd[2] = (block >> 16) & 0xFF;
591 	read_command->cmd[3] = (block >> 8) & 0xFF;
592 	read_command->cmd[4] = block & 0xFF;
593 	read_command->cmd[8] = (block_cnt >> 16) & 0xFF;
594 	read_command->cmd[9] = (block_cnt >> 8) & 0xFF;
595 	read_command->cmd[10] = block_cnt & 0xFF;
596 	/* set for DMA */
597 	__raw_writeb(1, GDROM_ERROR_REG);
598 	/* other registers */
599 	__raw_writeb(0, GDROM_SECNUM_REG);
600 	__raw_writeb(0, GDROM_BCL_REG);
601 	__raw_writeb(0, GDROM_BCH_REG);
602 	__raw_writeb(0, GDROM_DSEL_REG);
603 	__raw_writeb(0, GDROM_INTSEC_REG);
604 	/* Wait for registers to reset after any previous activity */
605 	timeout = jiffies + HZ / 2;
606 	while (gdrom_is_busy() && time_before(jiffies, timeout))
607 		cpu_relax();
608 	__raw_writeb(GDROM_COM_PACKET, GDROM_STATUSCOMMAND_REG);
609 	timeout = jiffies + HZ / 2;
610 	/* Wait for packet command to finish */
611 	while (gdrom_is_busy() && time_before(jiffies, timeout))
612 		cpu_relax();
613 	gd.pending = 1;
614 	gd.transfer = 1;
615 	outsw(GDROM_DATA_REG, &read_command->cmd, 6);
616 	timeout = jiffies + HZ / 2;
617 	/* Wait for any pending DMA to finish */
618 	while (__raw_readb(GDROM_DMA_STATUS_REG) &&
619 		time_before(jiffies, timeout))
620 		cpu_relax();
621 	/* start transfer */
622 	__raw_writeb(1, GDROM_DMA_STATUS_REG);
623 	wait_event_interruptible_timeout(request_queue,
624 		gd.transfer == 0, GDROM_DEFAULT_TIMEOUT);
625 	err = gd.transfer ? BLK_STS_IOERR : BLK_STS_OK;
626 	gd.transfer = 0;
627 	gd.pending = 0;
628 
629 	blk_mq_end_request(req, err);
630 	kfree(read_command);
631 	return BLK_STS_OK;
632 }
633 
634 static blk_status_t gdrom_queue_rq(struct blk_mq_hw_ctx *hctx,
635 				   const struct blk_mq_queue_data *bd)
636 {
637 	blk_mq_start_request(bd->rq);
638 
639 	switch (req_op(bd->rq)) {
640 	case REQ_OP_READ:
641 		return gdrom_readdisk_dma(bd->rq);
642 	case REQ_OP_WRITE:
643 		pr_notice("Read only device - write request ignored\n");
644 		return BLK_STS_IOERR;
645 	default:
646 		printk(KERN_DEBUG "gdrom: Non-fs request ignored\n");
647 		return BLK_STS_IOERR;
648 	}
649 }
650 
651 /* Print string identifying GD ROM device */
652 static int gdrom_outputversion(void)
653 {
654 	struct gdrom_id *id;
655 	char *model_name, *manuf_name, *firmw_ver;
656 	int err = -ENOMEM;
657 
658 	/* query device ID */
659 	id = kzalloc(sizeof(struct gdrom_id), GFP_KERNEL);
660 	if (!id)
661 		return err;
662 	gdrom_identifydevice(id);
663 	model_name = kstrndup(id->modname, 16, GFP_KERNEL);
664 	if (!model_name)
665 		goto free_id;
666 	manuf_name = kstrndup(id->mname, 16, GFP_KERNEL);
667 	if (!manuf_name)
668 		goto free_model_name;
669 	firmw_ver = kstrndup(id->firmver, 16, GFP_KERNEL);
670 	if (!firmw_ver)
671 		goto free_manuf_name;
672 	pr_info("%s from %s with firmware %s\n",
673 		model_name, manuf_name, firmw_ver);
674 	err = 0;
675 	kfree(firmw_ver);
676 free_manuf_name:
677 	kfree(manuf_name);
678 free_model_name:
679 	kfree(model_name);
680 free_id:
681 	kfree(id);
682 	return err;
683 }
684 
685 /* set the default mode for DMA transfer */
686 static int gdrom_init_dma_mode(void)
687 {
688 	__raw_writeb(0x13, GDROM_ERROR_REG);
689 	__raw_writeb(0x22, GDROM_INTSEC_REG);
690 	if (!gdrom_wait_clrbusy())
691 		return -EBUSY;
692 	__raw_writeb(0xEF, GDROM_STATUSCOMMAND_REG);
693 	if (!gdrom_wait_busy_sleeps())
694 		return -EBUSY;
695 	/* Memory protection setting for GDROM DMA
696 	* Bits 31 - 16 security: 0x8843
697 	* Bits 15 and 7 reserved (0)
698 	* Bits 14 - 8 start of transfer range in 1 MB blocks OR'ed with 0x80
699 	* Bits 6 - 0 end of transfer range in 1 MB blocks OR'ed with 0x80
700 	* (0x40 | 0x80) = start range at 0x0C000000
701 	* (0x7F | 0x80) = end range at 0x0FFFFFFF */
702 	__raw_writel(0x8843407F, GDROM_DMA_ACCESS_CTRL_REG);
703 	__raw_writel(9, GDROM_DMA_WAIT_REG); /* DMA word setting */
704 	return 0;
705 }
706 
707 static void probe_gdrom_setupcd(void)
708 {
709 	gd.cd_info->ops = &gdrom_ops;
710 	gd.cd_info->capacity = 1;
711 	strcpy(gd.cd_info->name, GDROM_DEV_NAME);
712 	gd.cd_info->mask = CDC_CLOSE_TRAY|CDC_OPEN_TRAY|CDC_LOCK|
713 		CDC_SELECT_DISC;
714 }
715 
716 static void probe_gdrom_setupdisk(void)
717 {
718 	gd.disk->major = gdrom_major;
719 	gd.disk->first_minor = 1;
720 	gd.disk->minors = 1;
721 	gd.disk->flags |= GENHD_FL_NO_PART;
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 	err = add_disk(gd.disk);
809 	if (err)
810 		goto probe_fail_add_disk;
811 
812 	return 0;
813 
814 probe_fail_add_disk:
815 	kfree(gd.toc);
816 probe_fail_free_irqs:
817 	free_irq(HW_EVENT_GDROM_DMA, &gd);
818 	free_irq(HW_EVENT_GDROM_CMD, &gd);
819 probe_fail_cleanup_disk:
820 	blk_cleanup_disk(gd.disk);
821 probe_fail_free_tag_set:
822 	blk_mq_free_tag_set(&gd.tag_set);
823 probe_fail_free_cd_info:
824 	kfree(gd.cd_info);
825 probe_fail_no_mem:
826 	unregister_blkdev(gdrom_major, GDROM_DEV_NAME);
827 	gdrom_major = 0;
828 	pr_warn("Probe failed - error is 0x%X\n", err);
829 	return err;
830 }
831 
832 static int remove_gdrom(struct platform_device *devptr)
833 {
834 	blk_cleanup_queue(gd.gdrom_rq);
835 	blk_mq_free_tag_set(&gd.tag_set);
836 	free_irq(HW_EVENT_GDROM_CMD, &gd);
837 	free_irq(HW_EVENT_GDROM_DMA, &gd);
838 	del_gendisk(gd.disk);
839 	if (gdrom_major)
840 		unregister_blkdev(gdrom_major, GDROM_DEV_NAME);
841 	unregister_cdrom(gd.cd_info);
842 	kfree(gd.cd_info);
843 	kfree(gd.toc);
844 
845 	return 0;
846 }
847 
848 static struct platform_driver gdrom_driver = {
849 	.probe = probe_gdrom,
850 	.remove = remove_gdrom,
851 	.driver = {
852 			.name = GDROM_DEV_NAME,
853 	},
854 };
855 
856 static int __init init_gdrom(void)
857 {
858 	int rc;
859 
860 	rc = platform_driver_register(&gdrom_driver);
861 	if (rc)
862 		return rc;
863 	pd = platform_device_register_simple(GDROM_DEV_NAME, -1, NULL, 0);
864 	if (IS_ERR(pd)) {
865 		platform_driver_unregister(&gdrom_driver);
866 		return PTR_ERR(pd);
867 	}
868 	return 0;
869 }
870 
871 static void __exit exit_gdrom(void)
872 {
873 	platform_device_unregister(pd);
874 	platform_driver_unregister(&gdrom_driver);
875 }
876 
877 module_init(init_gdrom);
878 module_exit(exit_gdrom);
879 MODULE_AUTHOR("Adrian McMenamin <adrian@mcmen.demon.co.uk>");
880 MODULE_DESCRIPTION("SEGA Dreamcast GD-ROM Driver");
881 MODULE_LICENSE("GPL");
882