xref: /openbmc/linux/drivers/cdrom/gdrom.c (revision 239480ab)
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 (__raw_readb(GDROM_ALTSTATUS_REG) & 0x80) != 0;
146 }
147 
148 static bool gdrom_data_request(void)
149 {
150 	return (__raw_readb(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 ((__raw_readb(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 	__raw_writeb(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] = __raw_readw(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 	__raw_writeb(0x08, GDROM_ALTSTATUS_REG);
201 	/* specify how many bytes we expect back */
202 	__raw_writeb(buflen & 0xFF, GDROM_BCL_REG);
203 	__raw_writeb((buflen >> 8) & 0xFF, GDROM_BCH_REG);
204 	/* other parameters */
205 	__raw_writeb(0, GDROM_INTSEC_REG);
206 	__raw_writeb(0, GDROM_SECNUM_REG);
207 	__raw_writeb(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 	__raw_writeb(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 	__raw_writeb(GDROM_COM_EXECDIAG, GDROM_STATUSCOMMAND_REG);
237 	if (!gdrom_wait_busy_sleeps())
238 		return 0;
239 	return __raw_readb(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 = __raw_readb(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 unsigned int gdrom_check_events(struct cdrom_device_info *cd_info,
399 				       unsigned int clearing, int ignore)
400 {
401 	/* check the sense key */
402 	return (__raw_readb(GDROM_ERROR_REG) & 0xF0) == 0x60 ?
403 		DISK_EVENT_MEDIA_CHANGE : 0;
404 }
405 
406 /* reset the G1 bus */
407 static int gdrom_hardreset(struct cdrom_device_info *cd_info)
408 {
409 	int count;
410 	__raw_writel(0x1fffff, GDROM_RESET_REG);
411 	for (count = 0xa0000000; count < 0xa0200000; count += 4)
412 		__raw_readl(count);
413 	return 0;
414 }
415 
416 /* keep the function looking like the universal
417  * CD Rom specification  - returning int */
418 static int gdrom_packetcommand(struct cdrom_device_info *cd_info,
419 	struct packet_command *command)
420 {
421 	gdrom_spicommand(&command->cmd, command->buflen);
422 	return 0;
423 }
424 
425 /* Get Sense SPI command
426  * From Marcus Comstedt
427  * cmd = 0x13
428  * cmd + 4 = length of returned buffer
429  * Returns 5 16 bit words
430  */
431 static int gdrom_getsense(short *bufstring)
432 {
433 	struct packet_command *sense_command;
434 	short sense[5];
435 	int sense_key;
436 	int err = -EIO;
437 
438 	sense_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
439 	if (!sense_command)
440 		return -ENOMEM;
441 	sense_command->cmd[0] = 0x13;
442 	sense_command->cmd[4] = 10;
443 	sense_command->buflen = 10;
444 	/* even if something is pending try to get
445 	* the sense key if possible */
446 	if (gd.pending && !gdrom_wait_clrbusy()) {
447 		err = -EBUSY;
448 		goto cleanup_sense_final;
449 	}
450 	gd.pending = 1;
451 	gdrom_packetcommand(gd.cd_info, sense_command);
452 	wait_event_interruptible_timeout(command_queue, gd.pending == 0,
453 		GDROM_DEFAULT_TIMEOUT);
454 	if (gd.pending)
455 		goto cleanup_sense;
456 	insw(GDROM_DATA_REG, &sense, sense_command->buflen/2);
457 	if (sense[1] & 40) {
458 		pr_info("Drive not ready - command aborted\n");
459 		goto cleanup_sense;
460 	}
461 	sense_key = sense[1] & 0x0F;
462 	if (sense_key < ARRAY_SIZE(sense_texts))
463 		pr_info("%s\n", sense_texts[sense_key].text);
464 	else
465 		pr_err("Unknown sense key: %d\n", sense_key);
466 	if (bufstring) /* return addional sense data */
467 		memcpy(bufstring, &sense[4], 2);
468 	if (sense_key < 2)
469 		err = 0;
470 
471 cleanup_sense:
472 	gd.pending = 0;
473 cleanup_sense_final:
474 	kfree(sense_command);
475 	return err;
476 }
477 
478 static int gdrom_audio_ioctl(struct cdrom_device_info *cdi, unsigned int cmd,
479 			     void *arg)
480 {
481 	return -EINVAL;
482 }
483 
484 static const struct cdrom_device_ops gdrom_ops = {
485 	.open			= gdrom_open,
486 	.release		= gdrom_release,
487 	.drive_status		= gdrom_drivestatus,
488 	.check_events		= gdrom_check_events,
489 	.get_last_session	= gdrom_get_last_session,
490 	.reset			= gdrom_hardreset,
491 	.audio_ioctl		= gdrom_audio_ioctl,
492 	.generic_packet		= cdrom_dummy_generic_packet,
493 	.capability		= CDC_MULTI_SESSION | CDC_MEDIA_CHANGED |
494 				  CDC_RESET | CDC_DRIVE_STATUS | CDC_CD_R,
495 };
496 
497 static int gdrom_bdops_open(struct block_device *bdev, fmode_t mode)
498 {
499 	int ret;
500 	mutex_lock(&gdrom_mutex);
501 	ret = cdrom_open(gd.cd_info, bdev, mode);
502 	mutex_unlock(&gdrom_mutex);
503 	return ret;
504 }
505 
506 static void gdrom_bdops_release(struct gendisk *disk, fmode_t mode)
507 {
508 	mutex_lock(&gdrom_mutex);
509 	cdrom_release(gd.cd_info, mode);
510 	mutex_unlock(&gdrom_mutex);
511 }
512 
513 static unsigned int gdrom_bdops_check_events(struct gendisk *disk,
514 					     unsigned int clearing)
515 {
516 	return cdrom_check_events(gd.cd_info, clearing);
517 }
518 
519 static int gdrom_bdops_ioctl(struct block_device *bdev, fmode_t mode,
520 	unsigned cmd, unsigned long arg)
521 {
522 	int ret;
523 
524 	mutex_lock(&gdrom_mutex);
525 	ret = cdrom_ioctl(gd.cd_info, bdev, mode, cmd, arg);
526 	mutex_unlock(&gdrom_mutex);
527 
528 	return ret;
529 }
530 
531 static const struct block_device_operations gdrom_bdops = {
532 	.owner			= THIS_MODULE,
533 	.open			= gdrom_bdops_open,
534 	.release		= gdrom_bdops_release,
535 	.check_events		= gdrom_bdops_check_events,
536 	.ioctl			= gdrom_bdops_ioctl,
537 };
538 
539 static irqreturn_t gdrom_command_interrupt(int irq, void *dev_id)
540 {
541 	gd.status = __raw_readb(GDROM_STATUSCOMMAND_REG);
542 	if (gd.pending != 1)
543 		return IRQ_HANDLED;
544 	gd.pending = 0;
545 	wake_up_interruptible(&command_queue);
546 	return IRQ_HANDLED;
547 }
548 
549 static irqreturn_t gdrom_dma_interrupt(int irq, void *dev_id)
550 {
551 	gd.status = __raw_readb(GDROM_STATUSCOMMAND_REG);
552 	if (gd.transfer != 1)
553 		return IRQ_HANDLED;
554 	gd.transfer = 0;
555 	wake_up_interruptible(&request_queue);
556 	return IRQ_HANDLED;
557 }
558 
559 static int gdrom_set_interrupt_handlers(void)
560 {
561 	int err;
562 
563 	err = request_irq(HW_EVENT_GDROM_CMD, gdrom_command_interrupt,
564 		0, "gdrom_command", &gd);
565 	if (err)
566 		return err;
567 	err = request_irq(HW_EVENT_GDROM_DMA, gdrom_dma_interrupt,
568 		0, "gdrom_dma", &gd);
569 	if (err)
570 		free_irq(HW_EVENT_GDROM_CMD, &gd);
571 	return err;
572 }
573 
574 /* Implement DMA read using SPI command
575  * 0 -> 0x30
576  * 1 -> mode
577  * 2 -> block >> 16
578  * 3 -> block >> 8
579  * 4 -> block
580  * 8 -> sectors >> 16
581  * 9 -> sectors >> 8
582  * 10 -> sectors
583  */
584 static void gdrom_readdisk_dma(struct work_struct *work)
585 {
586 	int err, block, block_cnt;
587 	struct packet_command *read_command;
588 	struct list_head *elem, *next;
589 	struct request *req;
590 	unsigned long timeout;
591 
592 	if (list_empty(&gdrom_deferred))
593 		return;
594 	read_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
595 	if (!read_command)
596 		return; /* get more memory later? */
597 	read_command->cmd[0] = 0x30;
598 	read_command->cmd[1] = 0x20;
599 	spin_lock(&gdrom_lock);
600 	list_for_each_safe(elem, next, &gdrom_deferred) {
601 		req = list_entry(elem, struct request, queuelist);
602 		spin_unlock(&gdrom_lock);
603 		block = blk_rq_pos(req)/GD_TO_BLK + GD_SESSION_OFFSET;
604 		block_cnt = blk_rq_sectors(req)/GD_TO_BLK;
605 		__raw_writel(virt_to_phys(bio_data(req->bio)), GDROM_DMA_STARTADDR_REG);
606 		__raw_writel(block_cnt * GDROM_HARD_SECTOR, GDROM_DMA_LENGTH_REG);
607 		__raw_writel(1, GDROM_DMA_DIRECTION_REG);
608 		__raw_writel(1, GDROM_DMA_ENABLE_REG);
609 		read_command->cmd[2] = (block >> 16) & 0xFF;
610 		read_command->cmd[3] = (block >> 8) & 0xFF;
611 		read_command->cmd[4] = block & 0xFF;
612 		read_command->cmd[8] = (block_cnt >> 16) & 0xFF;
613 		read_command->cmd[9] = (block_cnt >> 8) & 0xFF;
614 		read_command->cmd[10] = block_cnt & 0xFF;
615 		/* set for DMA */
616 		__raw_writeb(1, GDROM_ERROR_REG);
617 		/* other registers */
618 		__raw_writeb(0, GDROM_SECNUM_REG);
619 		__raw_writeb(0, GDROM_BCL_REG);
620 		__raw_writeb(0, GDROM_BCH_REG);
621 		__raw_writeb(0, GDROM_DSEL_REG);
622 		__raw_writeb(0, GDROM_INTSEC_REG);
623 		/* Wait for registers to reset after any previous activity */
624 		timeout = jiffies + HZ / 2;
625 		while (gdrom_is_busy() && time_before(jiffies, timeout))
626 			cpu_relax();
627 		__raw_writeb(GDROM_COM_PACKET, GDROM_STATUSCOMMAND_REG);
628 		timeout = jiffies + HZ / 2;
629 		/* Wait for packet command to finish */
630 		while (gdrom_is_busy() && time_before(jiffies, timeout))
631 			cpu_relax();
632 		gd.pending = 1;
633 		gd.transfer = 1;
634 		outsw(GDROM_DATA_REG, &read_command->cmd, 6);
635 		timeout = jiffies + HZ / 2;
636 		/* Wait for any pending DMA to finish */
637 		while (__raw_readb(GDROM_DMA_STATUS_REG) &&
638 			time_before(jiffies, timeout))
639 			cpu_relax();
640 		/* start transfer */
641 		__raw_writeb(1, GDROM_DMA_STATUS_REG);
642 		wait_event_interruptible_timeout(request_queue,
643 			gd.transfer == 0, GDROM_DEFAULT_TIMEOUT);
644 		err = gd.transfer ? -EIO : 0;
645 		gd.transfer = 0;
646 		gd.pending = 0;
647 		/* now seek to take the request spinlock
648 		* before handling ending the request */
649 		spin_lock(&gdrom_lock);
650 		list_del_init(&req->queuelist);
651 		__blk_end_request_all(req, err);
652 	}
653 	spin_unlock(&gdrom_lock);
654 	kfree(read_command);
655 }
656 
657 static void gdrom_request(struct request_queue *rq)
658 {
659 	struct request *req;
660 
661 	while ((req = blk_fetch_request(rq)) != NULL) {
662 		switch (req_op(req)) {
663 		case REQ_OP_READ:
664 			/*
665 			 * Add to list of deferred work and then schedule
666 			 * workqueue.
667 			 */
668 			list_add_tail(&req->queuelist, &gdrom_deferred);
669 			schedule_work(&work);
670 			break;
671 		case REQ_OP_WRITE:
672 			pr_notice("Read only device - write request ignored\n");
673 			__blk_end_request_all(req, -EIO);
674 			break;
675 		default:
676 			printk(KERN_DEBUG "gdrom: Non-fs request ignored\n");
677 			__blk_end_request_all(req, -EIO);
678 			break;
679 		}
680 	}
681 }
682 
683 /* Print string identifying GD ROM device */
684 static int gdrom_outputversion(void)
685 {
686 	struct gdrom_id *id;
687 	char *model_name, *manuf_name, *firmw_ver;
688 	int err = -ENOMEM;
689 
690 	/* query device ID */
691 	id = kzalloc(sizeof(struct gdrom_id), GFP_KERNEL);
692 	if (!id)
693 		return err;
694 	gdrom_identifydevice(id);
695 	model_name = kstrndup(id->modname, 16, GFP_KERNEL);
696 	if (!model_name)
697 		goto free_id;
698 	manuf_name = kstrndup(id->mname, 16, GFP_KERNEL);
699 	if (!manuf_name)
700 		goto free_model_name;
701 	firmw_ver = kstrndup(id->firmver, 16, GFP_KERNEL);
702 	if (!firmw_ver)
703 		goto free_manuf_name;
704 	pr_info("%s from %s with firmware %s\n",
705 		model_name, manuf_name, firmw_ver);
706 	err = 0;
707 	kfree(firmw_ver);
708 free_manuf_name:
709 	kfree(manuf_name);
710 free_model_name:
711 	kfree(model_name);
712 free_id:
713 	kfree(id);
714 	return err;
715 }
716 
717 /* set the default mode for DMA transfer */
718 static int gdrom_init_dma_mode(void)
719 {
720 	__raw_writeb(0x13, GDROM_ERROR_REG);
721 	__raw_writeb(0x22, GDROM_INTSEC_REG);
722 	if (!gdrom_wait_clrbusy())
723 		return -EBUSY;
724 	__raw_writeb(0xEF, GDROM_STATUSCOMMAND_REG);
725 	if (!gdrom_wait_busy_sleeps())
726 		return -EBUSY;
727 	/* Memory protection setting for GDROM DMA
728 	* Bits 31 - 16 security: 0x8843
729 	* Bits 15 and 7 reserved (0)
730 	* Bits 14 - 8 start of transfer range in 1 MB blocks OR'ed with 0x80
731 	* Bits 6 - 0 end of transfer range in 1 MB blocks OR'ed with 0x80
732 	* (0x40 | 0x80) = start range at 0x0C000000
733 	* (0x7F | 0x80) = end range at 0x0FFFFFFF */
734 	__raw_writel(0x8843407F, GDROM_DMA_ACCESS_CTRL_REG);
735 	__raw_writel(9, GDROM_DMA_WAIT_REG); /* DMA word setting */
736 	return 0;
737 }
738 
739 static void probe_gdrom_setupcd(void)
740 {
741 	gd.cd_info->ops = &gdrom_ops;
742 	gd.cd_info->capacity = 1;
743 	strcpy(gd.cd_info->name, GDROM_DEV_NAME);
744 	gd.cd_info->mask = CDC_CLOSE_TRAY|CDC_OPEN_TRAY|CDC_LOCK|
745 		CDC_SELECT_DISC;
746 }
747 
748 static void probe_gdrom_setupdisk(void)
749 {
750 	gd.disk->major = gdrom_major;
751 	gd.disk->first_minor = 1;
752 	gd.disk->minors = 1;
753 	strcpy(gd.disk->disk_name, GDROM_DEV_NAME);
754 }
755 
756 static int probe_gdrom_setupqueue(void)
757 {
758 	blk_queue_logical_block_size(gd.gdrom_rq, GDROM_HARD_SECTOR);
759 	/* using DMA so memory will need to be contiguous */
760 	blk_queue_max_segments(gd.gdrom_rq, 1);
761 	/* set a large max size to get most from DMA */
762 	blk_queue_max_segment_size(gd.gdrom_rq, 0x40000);
763 	gd.disk->queue = gd.gdrom_rq;
764 	return gdrom_init_dma_mode();
765 }
766 
767 /*
768  * register this as a block device and as compliant with the
769  * universal CD Rom driver interface
770  */
771 static int probe_gdrom(struct platform_device *devptr)
772 {
773 	int err;
774 	/* Start the device */
775 	if (gdrom_execute_diagnostic() != 1) {
776 		pr_warning("ATA Probe for GDROM failed\n");
777 		return -ENODEV;
778 	}
779 	/* Print out firmware ID */
780 	if (gdrom_outputversion())
781 		return -ENOMEM;
782 	/* Register GDROM */
783 	gdrom_major = register_blkdev(0, GDROM_DEV_NAME);
784 	if (gdrom_major <= 0)
785 		return gdrom_major;
786 	pr_info("Registered with major number %d\n",
787 		gdrom_major);
788 	/* Specify basic properties of drive */
789 	gd.cd_info = kzalloc(sizeof(struct cdrom_device_info), GFP_KERNEL);
790 	if (!gd.cd_info) {
791 		err = -ENOMEM;
792 		goto probe_fail_no_mem;
793 	}
794 	probe_gdrom_setupcd();
795 	gd.disk = alloc_disk(1);
796 	if (!gd.disk) {
797 		err = -ENODEV;
798 		goto probe_fail_no_disk;
799 	}
800 	probe_gdrom_setupdisk();
801 	if (register_cdrom(gd.cd_info)) {
802 		err = -ENODEV;
803 		goto probe_fail_cdrom_register;
804 	}
805 	gd.disk->fops = &gdrom_bdops;
806 	/* latch on to the interrupt */
807 	err = gdrom_set_interrupt_handlers();
808 	if (err)
809 		goto probe_fail_cmdirq_register;
810 	gd.gdrom_rq = blk_init_queue(gdrom_request, &gdrom_lock);
811 	if (!gd.gdrom_rq) {
812 		err = -ENOMEM;
813 		goto probe_fail_requestq;
814 	}
815 
816 	err = probe_gdrom_setupqueue();
817 	if (err)
818 		goto probe_fail_toc;
819 
820 	gd.toc = kzalloc(sizeof(struct gdromtoc), GFP_KERNEL);
821 	if (!gd.toc) {
822 		err = -ENOMEM;
823 		goto probe_fail_toc;
824 	}
825 	add_disk(gd.disk);
826 	return 0;
827 
828 probe_fail_toc:
829 	blk_cleanup_queue(gd.gdrom_rq);
830 probe_fail_requestq:
831 	free_irq(HW_EVENT_GDROM_DMA, &gd);
832 	free_irq(HW_EVENT_GDROM_CMD, &gd);
833 probe_fail_cmdirq_register:
834 probe_fail_cdrom_register:
835 	del_gendisk(gd.disk);
836 probe_fail_no_disk:
837 	kfree(gd.cd_info);
838 probe_fail_no_mem:
839 	unregister_blkdev(gdrom_major, GDROM_DEV_NAME);
840 	gdrom_major = 0;
841 	pr_warning("Probe failed - error is 0x%X\n", err);
842 	return err;
843 }
844 
845 static int remove_gdrom(struct platform_device *devptr)
846 {
847 	flush_work(&work);
848 	blk_cleanup_queue(gd.gdrom_rq);
849 	free_irq(HW_EVENT_GDROM_CMD, &gd);
850 	free_irq(HW_EVENT_GDROM_DMA, &gd);
851 	del_gendisk(gd.disk);
852 	if (gdrom_major)
853 		unregister_blkdev(gdrom_major, GDROM_DEV_NAME);
854 	unregister_cdrom(gd.cd_info);
855 
856 	return 0;
857 }
858 
859 static struct platform_driver gdrom_driver = {
860 	.probe = probe_gdrom,
861 	.remove = remove_gdrom,
862 	.driver = {
863 			.name = GDROM_DEV_NAME,
864 	},
865 };
866 
867 static int __init init_gdrom(void)
868 {
869 	int rc;
870 	gd.toc = NULL;
871 	rc = platform_driver_register(&gdrom_driver);
872 	if (rc)
873 		return rc;
874 	pd = platform_device_register_simple(GDROM_DEV_NAME, -1, NULL, 0);
875 	if (IS_ERR(pd)) {
876 		platform_driver_unregister(&gdrom_driver);
877 		return PTR_ERR(pd);
878 	}
879 	return 0;
880 }
881 
882 static void __exit exit_gdrom(void)
883 {
884 	platform_device_unregister(pd);
885 	platform_driver_unregister(&gdrom_driver);
886 	kfree(gd.toc);
887 }
888 
889 module_init(init_gdrom);
890 module_exit(exit_gdrom);
891 MODULE_AUTHOR("Adrian McMenamin <adrian@mcmen.demon.co.uk>");
892 MODULE_DESCRIPTION("SEGA Dreamcast GD-ROM Driver");
893 MODULE_LICENSE("GPL");
894