xref: /openbmc/linux/drivers/cdrom/gdrom.c (revision 643d1f7f)
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 #include <linux/init.h>
23 #include <linux/module.h>
24 #include <linux/fs.h>
25 #include <linux/kernel.h>
26 #include <linux/list.h>
27 #include <linux/slab.h>
28 #include <linux/dma-mapping.h>
29 #include <linux/cdrom.h>
30 #include <linux/genhd.h>
31 #include <linux/bio.h>
32 #include <linux/blkdev.h>
33 #include <linux/interrupt.h>
34 #include <linux/device.h>
35 #include <linux/wait.h>
36 #include <linux/workqueue.h>
37 #include <linux/platform_device.h>
38 #include <scsi/scsi.h>
39 #include <asm/io.h>
40 #include <asm/dma.h>
41 #include <asm/delay.h>
42 #include <asm/mach/dma.h>
43 #include <asm/mach/sysasic.h>
44 
45 #define GDROM_DEV_NAME "gdrom"
46 #define GD_SESSION_OFFSET 150
47 
48 /* GD Rom commands */
49 #define GDROM_COM_SOFTRESET 0x08
50 #define GDROM_COM_EXECDIAG 0x90
51 #define GDROM_COM_PACKET 0xA0
52 #define GDROM_COM_IDDEV 0xA1
53 
54 /* GD Rom registers */
55 #define GDROM_BASE_REG			0xA05F7000
56 #define GDROM_ALTSTATUS_REG		(GDROM_BASE_REG + 0x18)
57 #define GDROM_DATA_REG			(GDROM_BASE_REG + 0x80)
58 #define GDROM_ERROR_REG		(GDROM_BASE_REG + 0x84)
59 #define GDROM_INTSEC_REG		(GDROM_BASE_REG + 0x88)
60 #define GDROM_SECNUM_REG		(GDROM_BASE_REG + 0x8C)
61 #define GDROM_BCL_REG			(GDROM_BASE_REG + 0x90)
62 #define GDROM_BCH_REG			(GDROM_BASE_REG + 0x94)
63 #define GDROM_DSEL_REG			(GDROM_BASE_REG + 0x98)
64 #define GDROM_STATUSCOMMAND_REG	(GDROM_BASE_REG + 0x9C)
65 #define GDROM_RESET_REG		(GDROM_BASE_REG + 0x4E4)
66 
67 #define GDROM_DMA_STARTADDR_REG	(GDROM_BASE_REG + 0x404)
68 #define GDROM_DMA_LENGTH_REG		(GDROM_BASE_REG + 0x408)
69 #define GDROM_DMA_DIRECTION_REG	(GDROM_BASE_REG + 0x40C)
70 #define GDROM_DMA_ENABLE_REG		(GDROM_BASE_REG + 0x414)
71 #define GDROM_DMA_STATUS_REG		(GDROM_BASE_REG + 0x418)
72 #define GDROM_DMA_WAIT_REG		(GDROM_BASE_REG + 0x4A0)
73 #define GDROM_DMA_ACCESS_CTRL_REG	(GDROM_BASE_REG + 0x4B8)
74 
75 #define GDROM_HARD_SECTOR	2048
76 #define BLOCK_LAYER_SECTOR	512
77 #define GD_TO_BLK		4
78 
79 #define GDROM_DEFAULT_TIMEOUT	(HZ * 7)
80 
81 static const struct {
82 	int sense_key;
83 	const char * const text;
84 } sense_texts[] = {
85 	{NO_SENSE, "OK"},
86 	{RECOVERED_ERROR, "Recovered from error"},
87 	{NOT_READY, "Device not ready"},
88 	{MEDIUM_ERROR, "Disk not ready"},
89 	{HARDWARE_ERROR, "Hardware error"},
90 	{ILLEGAL_REQUEST, "Command has failed"},
91 	{UNIT_ATTENTION, "Device needs attention - disk may have been changed"},
92 	{DATA_PROTECT, "Data protection error"},
93 	{ABORTED_COMMAND, "Command aborted"},
94 };
95 
96 static struct platform_device *pd;
97 static int gdrom_major;
98 static DECLARE_WAIT_QUEUE_HEAD(command_queue);
99 static DECLARE_WAIT_QUEUE_HEAD(request_queue);
100 
101 static DEFINE_SPINLOCK(gdrom_lock);
102 static void gdrom_readdisk_dma(struct work_struct *work);
103 static DECLARE_WORK(work, gdrom_readdisk_dma);
104 static LIST_HEAD(gdrom_deferred);
105 
106 struct gdromtoc {
107 	unsigned int entry[99];
108 	unsigned int first, last;
109 	unsigned int leadout;
110 };
111 
112 static struct gdrom_unit {
113 	struct gendisk *disk;
114 	struct cdrom_device_info *cd_info;
115 	int status;
116 	int pending;
117 	int transfer;
118 	char disk_type;
119 	struct gdromtoc *toc;
120 	struct request_queue *gdrom_rq;
121 } gd;
122 
123 struct gdrom_id {
124 	char mid;
125 	char modid;
126 	char verid;
127 	char padA[13];
128 	char mname[16];
129 	char modname[16];
130 	char firmver[16];
131 	char padB[16];
132 };
133 
134 static int gdrom_getsense(short *bufstring);
135 static int gdrom_packetcommand(struct cdrom_device_info *cd_info,
136 	struct packet_command *command);
137 static int gdrom_hardreset(struct cdrom_device_info *cd_info);
138 
139 static bool gdrom_is_busy(void)
140 {
141 	return (ctrl_inb(GDROM_ALTSTATUS_REG) & 0x80) != 0;
142 }
143 
144 static bool gdrom_data_request(void)
145 {
146 	return (ctrl_inb(GDROM_ALTSTATUS_REG) & 0x88) == 8;
147 }
148 
149 static bool gdrom_wait_clrbusy(void)
150 {
151 	unsigned long timeout = jiffies + GDROM_DEFAULT_TIMEOUT;
152 	while ((ctrl_inb(GDROM_ALTSTATUS_REG) & 0x80) &&
153 		(time_before(jiffies, timeout)))
154 		cpu_relax();
155 	return time_before(jiffies, timeout + 1);
156 }
157 
158 static bool gdrom_wait_busy_sleeps(void)
159 {
160 	unsigned long timeout;
161 	/* Wait to get busy first */
162 	timeout = jiffies + GDROM_DEFAULT_TIMEOUT;
163 	while (!gdrom_is_busy() && time_before(jiffies, timeout))
164 		cpu_relax();
165 	/* Now wait for busy to clear */
166 	return gdrom_wait_clrbusy();
167 }
168 
169 static void gdrom_identifydevice(void *buf)
170 {
171 	int c;
172 	short *data = buf;
173 	/* If the device won't clear it has probably
174 	* been hit by a serious failure - but we'll
175 	* try to return a sense key even so */
176 	if (!gdrom_wait_clrbusy()) {
177 		gdrom_getsense(NULL);
178 		return;
179 	}
180 	ctrl_outb(GDROM_COM_IDDEV, GDROM_STATUSCOMMAND_REG);
181 	if (!gdrom_wait_busy_sleeps()) {
182 		gdrom_getsense(NULL);
183 		return;
184 	}
185 	/* now read in the data */
186 	for (c = 0; c < 40; c++)
187 		data[c] = ctrl_inw(GDROM_DATA_REG);
188 }
189 
190 static void gdrom_spicommand(void *spi_string, int buflen)
191 {
192 	short *cmd = spi_string;
193 	unsigned long timeout;
194 
195 	/* ensure IRQ_WAIT is set */
196 	ctrl_outb(0x08, GDROM_ALTSTATUS_REG);
197 	/* specify how many bytes we expect back */
198 	ctrl_outb(buflen & 0xFF, GDROM_BCL_REG);
199 	ctrl_outb((buflen >> 8) & 0xFF, GDROM_BCH_REG);
200 	/* other parameters */
201 	ctrl_outb(0, GDROM_INTSEC_REG);
202 	ctrl_outb(0, GDROM_SECNUM_REG);
203 	ctrl_outb(0, GDROM_ERROR_REG);
204 	/* Wait until we can go */
205 	if (!gdrom_wait_clrbusy()) {
206 		gdrom_getsense(NULL);
207 		return;
208 	}
209 	timeout = jiffies + GDROM_DEFAULT_TIMEOUT;
210 	ctrl_outb(GDROM_COM_PACKET, GDROM_STATUSCOMMAND_REG);
211 	while (!gdrom_data_request() && time_before(jiffies, timeout))
212 		cpu_relax();
213 	if (!time_before(jiffies, timeout + 1)) {
214 		gdrom_getsense(NULL);
215 		return;
216 	}
217 	outsw(PHYSADDR(GDROM_DATA_REG), cmd, 6);
218 }
219 
220 
221 /* gdrom_command_executediagnostic:
222  * Used to probe for presence of working GDROM
223  * Restarts GDROM device and then applies standard ATA 3
224  * Execute Diagnostic Command: a return of '1' indicates device 0
225  * present and device 1 absent
226  */
227 static char gdrom_execute_diagnostic(void)
228 {
229 	gdrom_hardreset(gd.cd_info);
230 	if (!gdrom_wait_clrbusy())
231 		return 0;
232 	ctrl_outb(GDROM_COM_EXECDIAG, GDROM_STATUSCOMMAND_REG);
233 	if (!gdrom_wait_busy_sleeps())
234 		return 0;
235 	return ctrl_inb(GDROM_ERROR_REG);
236 }
237 
238 /*
239  * Prepare disk command
240  * byte 0 = 0x70
241  * byte 1 = 0x1f
242  */
243 static int gdrom_preparedisk_cmd(void)
244 {
245 	struct packet_command *spin_command;
246 	spin_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
247 	if (!spin_command)
248 		return -ENOMEM;
249 	spin_command->cmd[0] = 0x70;
250 	spin_command->cmd[2] = 0x1f;
251 	spin_command->buflen = 0;
252 	gd.pending = 1;
253 	gdrom_packetcommand(gd.cd_info, spin_command);
254 	/* 60 second timeout */
255 	wait_event_interruptible_timeout(command_queue, gd.pending == 0,
256 		GDROM_DEFAULT_TIMEOUT);
257 	gd.pending = 0;
258 	kfree(spin_command);
259 	if (gd.status & 0x01) {
260 		/* log an error */
261 		gdrom_getsense(NULL);
262 		return -EIO;
263 	}
264 	return 0;
265 }
266 
267 /*
268  * Read TOC command
269  * byte 0 = 0x14
270  * byte 1 = session
271  * byte 3 = sizeof TOC >> 8  ie upper byte
272  * byte 4 = sizeof TOC & 0xff ie lower byte
273  */
274 static int gdrom_readtoc_cmd(struct gdromtoc *toc, int session)
275 {
276 	int tocsize;
277 	struct packet_command *toc_command;
278 	int err = 0;
279 
280 	toc_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
281 	if (!toc_command)
282 		return -ENOMEM;
283 	tocsize = sizeof(struct gdromtoc);
284 	toc_command->cmd[0] = 0x14;
285 	toc_command->cmd[1] = session;
286 	toc_command->cmd[3] = tocsize >> 8;
287 	toc_command->cmd[4] = tocsize & 0xff;
288 	toc_command->buflen = tocsize;
289 	if (gd.pending) {
290 		err = -EBUSY;
291 		goto cleanup_readtoc_final;
292 	}
293 	gd.pending = 1;
294 	gdrom_packetcommand(gd.cd_info, toc_command);
295 	wait_event_interruptible_timeout(command_queue, gd.pending == 0,
296 		GDROM_DEFAULT_TIMEOUT);
297 	if (gd.pending) {
298 		err = -EINVAL;
299 		goto cleanup_readtoc;
300 	}
301 	insw(PHYSADDR(GDROM_DATA_REG), toc, tocsize/2);
302 	if (gd.status & 0x01)
303 		err = -EINVAL;
304 
305 cleanup_readtoc:
306 	gd.pending = 0;
307 cleanup_readtoc_final:
308 	kfree(toc_command);
309 	return err;
310 }
311 
312 /* TOC helpers */
313 static int get_entry_lba(int track)
314 {
315 	return (cpu_to_be32(track & 0xffffff00) - GD_SESSION_OFFSET);
316 }
317 
318 static int get_entry_q_ctrl(int track)
319 {
320 	return (track & 0x000000f0) >> 4;
321 }
322 
323 static int get_entry_track(int track)
324 {
325 	return (track & 0x0000ff00) >> 8;
326 }
327 
328 static int gdrom_get_last_session(struct cdrom_device_info *cd_info,
329 	struct cdrom_multisession *ms_info)
330 {
331 	int fentry, lentry, track, data, tocuse, err;
332 	if (!gd.toc)
333 		return -ENOMEM;
334 	tocuse = 1;
335 	/* Check if GD-ROM */
336 	err = gdrom_readtoc_cmd(gd.toc, 1);
337 	/* Not a GD-ROM so check if standard CD-ROM */
338 	if (err) {
339 		tocuse = 0;
340 		err = gdrom_readtoc_cmd(gd.toc, 0);
341 		if (err) {
342 			printk(KERN_INFO "GDROM: Could not get CD "
343 				"table of contents\n");
344 			return -ENXIO;
345 		}
346 	}
347 
348 	fentry = get_entry_track(gd.toc->first);
349 	lentry = get_entry_track(gd.toc->last);
350 	/* Find the first data track */
351 	track = get_entry_track(gd.toc->last);
352 	do {
353 		data = gd.toc->entry[track - 1];
354 		if (get_entry_q_ctrl(data))
355 			break;	/* ie a real data track */
356 		track--;
357 	} while (track >= fentry);
358 
359 	if ((track > 100) || (track < get_entry_track(gd.toc->first))) {
360 		printk(KERN_INFO "GDROM: No data on the last "
361 			"session of the CD\n");
362 		gdrom_getsense(NULL);
363 		return -ENXIO;
364 	}
365 
366 	ms_info->addr_format = CDROM_LBA;
367 	ms_info->addr.lba = get_entry_lba(data);
368 	ms_info->xa_flag = 1;
369 	return 0;
370 }
371 
372 static int gdrom_open(struct cdrom_device_info *cd_info, int purpose)
373 {
374 	/* spin up the disk */
375 	return gdrom_preparedisk_cmd();
376 }
377 
378 /* this function is required even if empty */
379 static void gdrom_release(struct cdrom_device_info *cd_info)
380 {
381 }
382 
383 static int gdrom_drivestatus(struct cdrom_device_info *cd_info, int ignore)
384 {
385 	/* read the sense key */
386 	char sense = ctrl_inb(GDROM_ERROR_REG);
387 	sense &= 0xF0;
388 	if (sense == 0)
389 		return CDS_DISC_OK;
390 	if (sense == 0x20)
391 		return CDS_DRIVE_NOT_READY;
392 	/* default */
393 	return CDS_NO_INFO;
394 }
395 
396 static int gdrom_mediachanged(struct cdrom_device_info *cd_info, int ignore)
397 {
398 	/* check the sense key */
399 	return (ctrl_inb(GDROM_ERROR_REG) & 0xF0) == 0x60;
400 }
401 
402 /* reset the G1 bus */
403 static int gdrom_hardreset(struct cdrom_device_info *cd_info)
404 {
405 	int count;
406 	ctrl_outl(0x1fffff, GDROM_RESET_REG);
407 	for (count = 0xa0000000; count < 0xa0200000; count += 4)
408 		ctrl_inl(count);
409 	return 0;
410 }
411 
412 /* keep the function looking like the universal
413  * CD Rom specification  - returning int */
414 static int gdrom_packetcommand(struct cdrom_device_info *cd_info,
415 	struct packet_command *command)
416 {
417 	gdrom_spicommand(&command->cmd, command->buflen);
418 	return 0;
419 }
420 
421 /* Get Sense SPI command
422  * From Marcus Comstedt
423  * cmd = 0x13
424  * cmd + 4 = length of returned buffer
425  * Returns 5 16 bit words
426  */
427 static int gdrom_getsense(short *bufstring)
428 {
429 	struct packet_command *sense_command;
430 	short sense[5];
431 	int sense_key;
432 	int err = -EIO;
433 
434 	sense_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
435 	if (!sense_command)
436 		return -ENOMEM;
437 	sense_command->cmd[0] = 0x13;
438 	sense_command->cmd[4] = 10;
439 	sense_command->buflen = 10;
440 	/* even if something is pending try to get
441 	* the sense key if possible */
442 	if (gd.pending && !gdrom_wait_clrbusy()) {
443 		err = -EBUSY;
444 		goto cleanup_sense_final;
445 	}
446 	gd.pending = 1;
447 	gdrom_packetcommand(gd.cd_info, sense_command);
448 	wait_event_interruptible_timeout(command_queue, gd.pending == 0,
449 		GDROM_DEFAULT_TIMEOUT);
450 	if (gd.pending)
451 		goto cleanup_sense;
452 	insw(PHYSADDR(GDROM_DATA_REG), &sense, sense_command->buflen/2);
453 	if (sense[1] & 40) {
454 		printk(KERN_INFO "GDROM: Drive not ready - command aborted\n");
455 		goto cleanup_sense;
456 	}
457 	sense_key = sense[1] & 0x0F;
458 	if (sense_key < ARRAY_SIZE(sense_texts))
459 		printk(KERN_INFO "GDROM: %s\n", sense_texts[sense_key].text);
460 	else
461 		printk(KERN_ERR "GDROM: Unknown sense key: %d\n", sense_key);
462 	if (bufstring) /* return addional sense data */
463 		memcpy(bufstring, &sense[4], 2);
464 	if (sense_key < 2)
465 		err = 0;
466 
467 cleanup_sense:
468 	gd.pending = 0;
469 cleanup_sense_final:
470 	kfree(sense_command);
471 	return err;
472 }
473 
474 static struct cdrom_device_ops gdrom_ops = {
475 	.open			= gdrom_open,
476 	.release		= gdrom_release,
477 	.drive_status		= gdrom_drivestatus,
478 	.media_changed		= gdrom_mediachanged,
479 	.get_last_session	= gdrom_get_last_session,
480 	.reset			= gdrom_hardreset,
481 	.capability		= CDC_MULTI_SESSION | CDC_MEDIA_CHANGED |
482 				  CDC_RESET | CDC_DRIVE_STATUS | CDC_CD_R,
483 	.n_minors		= 1,
484 };
485 
486 static int gdrom_bdops_open(struct inode *inode, struct file *file)
487 {
488 	return cdrom_open(gd.cd_info, inode, file);
489 }
490 
491 static int gdrom_bdops_release(struct inode *inode, struct file *file)
492 {
493 	return cdrom_release(gd.cd_info, file);
494 }
495 
496 static int gdrom_bdops_mediachanged(struct gendisk *disk)
497 {
498 	return cdrom_media_changed(gd.cd_info);
499 }
500 
501 static int gdrom_bdops_ioctl(struct inode *inode, struct file *file,
502 	unsigned cmd, unsigned long arg)
503 {
504 	return cdrom_ioctl(file, gd.cd_info, inode, cmd, arg);
505 }
506 
507 static struct block_device_operations gdrom_bdops = {
508 	.owner			= THIS_MODULE,
509 	.open			= gdrom_bdops_open,
510 	.release		= gdrom_bdops_release,
511 	.media_changed		= gdrom_bdops_mediachanged,
512 	.ioctl			= gdrom_bdops_ioctl,
513 };
514 
515 static irqreturn_t gdrom_command_interrupt(int irq, void *dev_id)
516 {
517 	gd.status = ctrl_inb(GDROM_STATUSCOMMAND_REG);
518 	if (gd.pending != 1)
519 		return IRQ_HANDLED;
520 	gd.pending = 0;
521 	wake_up_interruptible(&command_queue);
522 	return IRQ_HANDLED;
523 }
524 
525 static irqreturn_t gdrom_dma_interrupt(int irq, void *dev_id)
526 {
527 	gd.status = ctrl_inb(GDROM_STATUSCOMMAND_REG);
528 	if (gd.transfer != 1)
529 		return IRQ_HANDLED;
530 	gd.transfer = 0;
531 	wake_up_interruptible(&request_queue);
532 	return IRQ_HANDLED;
533 }
534 
535 static int __devinit gdrom_set_interrupt_handlers(void)
536 {
537 	int err;
538 
539 	err = request_irq(HW_EVENT_GDROM_CMD, gdrom_command_interrupt,
540 		IRQF_DISABLED, "gdrom_command", &gd);
541 	if (err)
542 		return err;
543 	err = request_irq(HW_EVENT_GDROM_DMA, gdrom_dma_interrupt,
544 		IRQF_DISABLED, "gdrom_dma", &gd);
545 	if (err)
546 		free_irq(HW_EVENT_GDROM_CMD, &gd);
547 	return err;
548 }
549 
550 /* Implement DMA read using SPI command
551  * 0 -> 0x30
552  * 1 -> mode
553  * 2 -> block >> 16
554  * 3 -> block >> 8
555  * 4 -> block
556  * 8 -> sectors >> 16
557  * 9 -> sectors >> 8
558  * 10 -> sectors
559  */
560 static void gdrom_readdisk_dma(struct work_struct *work)
561 {
562 	int err, block, block_cnt;
563 	struct packet_command *read_command;
564 	struct list_head *elem, *next;
565 	struct request *req;
566 	unsigned long timeout;
567 
568 	if (list_empty(&gdrom_deferred))
569 		return;
570 	read_command = kzalloc(sizeof(struct packet_command), GFP_KERNEL);
571 	if (!read_command)
572 		return; /* get more memory later? */
573 	read_command->cmd[0] = 0x30;
574 	read_command->cmd[1] = 0x20;
575 	spin_lock(&gdrom_lock);
576 	list_for_each_safe(elem, next, &gdrom_deferred) {
577 		req = list_entry(elem, struct request, queuelist);
578 		spin_unlock(&gdrom_lock);
579 		block = req->sector/GD_TO_BLK + GD_SESSION_OFFSET;
580 		block_cnt = req->nr_sectors/GD_TO_BLK;
581 		ctrl_outl(PHYSADDR(req->buffer), GDROM_DMA_STARTADDR_REG);
582 		ctrl_outl(block_cnt * GDROM_HARD_SECTOR, GDROM_DMA_LENGTH_REG);
583 		ctrl_outl(1, GDROM_DMA_DIRECTION_REG);
584 		ctrl_outl(1, GDROM_DMA_ENABLE_REG);
585 		read_command->cmd[2] = (block >> 16) & 0xFF;
586 		read_command->cmd[3] = (block >> 8) & 0xFF;
587 		read_command->cmd[4] = block & 0xFF;
588 		read_command->cmd[8] = (block_cnt >> 16) & 0xFF;
589 		read_command->cmd[9] = (block_cnt >> 8) & 0xFF;
590 		read_command->cmd[10] = block_cnt & 0xFF;
591 		/* set for DMA */
592 		ctrl_outb(1, GDROM_ERROR_REG);
593 		/* other registers */
594 		ctrl_outb(0, GDROM_SECNUM_REG);
595 		ctrl_outb(0, GDROM_BCL_REG);
596 		ctrl_outb(0, GDROM_BCH_REG);
597 		ctrl_outb(0, GDROM_DSEL_REG);
598 		ctrl_outb(0, GDROM_INTSEC_REG);
599 		/* Wait for registers to reset after any previous activity */
600 		timeout = jiffies + HZ / 2;
601 		while (gdrom_is_busy() && time_before(jiffies, timeout))
602 			cpu_relax();
603 		ctrl_outb(GDROM_COM_PACKET, GDROM_STATUSCOMMAND_REG);
604 		timeout = jiffies + HZ / 2;
605 		/* Wait for packet command to finish */
606 		while (gdrom_is_busy() && time_before(jiffies, timeout))
607 			cpu_relax();
608 		gd.pending = 1;
609 		gd.transfer = 1;
610 		outsw(PHYSADDR(GDROM_DATA_REG), &read_command->cmd, 6);
611 		timeout = jiffies + HZ / 2;
612 		/* Wait for any pending DMA to finish */
613 		while (ctrl_inb(GDROM_DMA_STATUS_REG) &&
614 			time_before(jiffies, timeout))
615 			cpu_relax();
616 		/* start transfer */
617 		ctrl_outb(1, GDROM_DMA_STATUS_REG);
618 		wait_event_interruptible_timeout(request_queue,
619 			gd.transfer == 0, GDROM_DEFAULT_TIMEOUT);
620 		err = gd.transfer;
621 		gd.transfer = 0;
622 		gd.pending = 0;
623 		/* now seek to take the request spinlock
624 		* before handling ending the request */
625 		spin_lock(&gdrom_lock);
626 		list_del_init(&req->queuelist);
627 		end_dequeued_request(req, 1 - err);
628 	}
629 	spin_unlock(&gdrom_lock);
630 	kfree(read_command);
631 }
632 
633 static void gdrom_request_handler_dma(struct request *req)
634 {
635 	/* dequeue, add to list of deferred work
636 	* and then schedule workqueue */
637 	blkdev_dequeue_request(req);
638 	list_add_tail(&req->queuelist, &gdrom_deferred);
639 	schedule_work(&work);
640 }
641 
642 static void gdrom_request(struct request_queue *rq)
643 {
644 	struct request *req;
645 
646 	while ((req = elv_next_request(rq)) != NULL) {
647 		if (!blk_fs_request(req)) {
648 			printk(KERN_DEBUG "GDROM: Non-fs request ignored\n");
649 			end_request(req, 0);
650 		}
651 		if (rq_data_dir(req) != READ) {
652 			printk(KERN_NOTICE "GDROM: Read only device -");
653 			printk(" write request ignored\n");
654 			end_request(req, 0);
655 		}
656 		if (req->nr_sectors)
657 			gdrom_request_handler_dma(req);
658 		else
659 			end_request(req, 0);
660 	}
661 }
662 
663 /* Print string identifying GD ROM device */
664 static int __devinit gdrom_outputversion(void)
665 {
666 	struct gdrom_id *id;
667 	char *model_name, *manuf_name, *firmw_ver;
668 	int err = -ENOMEM;
669 
670 	/* query device ID */
671 	id = kzalloc(sizeof(struct gdrom_id), GFP_KERNEL);
672 	if (!id)
673 		return err;
674 	gdrom_identifydevice(id);
675 	model_name = kstrndup(id->modname, 16, GFP_KERNEL);
676 	if (!model_name)
677 		goto free_id;
678 	manuf_name = kstrndup(id->mname, 16, GFP_KERNEL);
679 	if (!manuf_name)
680 		goto free_model_name;
681 	firmw_ver = kstrndup(id->firmver, 16, GFP_KERNEL);
682 	if (!firmw_ver)
683 		goto free_manuf_name;
684 	printk(KERN_INFO "GDROM: %s from %s with firmware %s\n",
685 		model_name, manuf_name, firmw_ver);
686 	err = 0;
687 	kfree(firmw_ver);
688 free_manuf_name:
689 	kfree(manuf_name);
690 free_model_name:
691 	kfree(model_name);
692 free_id:
693 	kfree(id);
694 	return err;
695 }
696 
697 /* set the default mode for DMA transfer */
698 static int __devinit gdrom_init_dma_mode(void)
699 {
700 	ctrl_outb(0x13, GDROM_ERROR_REG);
701 	ctrl_outb(0x22, GDROM_INTSEC_REG);
702 	if (!gdrom_wait_clrbusy())
703 		return -EBUSY;
704 	ctrl_outb(0xEF, GDROM_STATUSCOMMAND_REG);
705 	if (!gdrom_wait_busy_sleeps())
706 		return -EBUSY;
707 	/* Memory protection setting for GDROM DMA
708 	* Bits 31 - 16 security: 0x8843
709 	* Bits 15 and 7 reserved (0)
710 	* Bits 14 - 8 start of transfer range in 1 MB blocks OR'ed with 0x80
711 	* Bits 6 - 0 end of transfer range in 1 MB blocks OR'ed with 0x80
712 	* (0x40 | 0x80) = start range at 0x0C000000
713 	* (0x7F | 0x80) = end range at 0x0FFFFFFF */
714 	ctrl_outl(0x8843407F, GDROM_DMA_ACCESS_CTRL_REG);
715 	ctrl_outl(9, GDROM_DMA_WAIT_REG); /* DMA word setting */
716 	return 0;
717 }
718 
719 static void __devinit probe_gdrom_setupcd(void)
720 {
721 	gd.cd_info->ops = &gdrom_ops;
722 	gd.cd_info->capacity = 1;
723 	strcpy(gd.cd_info->name, GDROM_DEV_NAME);
724 	gd.cd_info->mask = CDC_CLOSE_TRAY|CDC_OPEN_TRAY|CDC_LOCK|
725 		CDC_SELECT_DISC;
726 }
727 
728 static void __devinit probe_gdrom_setupdisk(void)
729 {
730 	gd.disk->major = gdrom_major;
731 	gd.disk->first_minor = 1;
732 	gd.disk->minors = 1;
733 	strcpy(gd.disk->disk_name, GDROM_DEV_NAME);
734 }
735 
736 static int __devinit probe_gdrom_setupqueue(void)
737 {
738 	blk_queue_hardsect_size(gd.gdrom_rq, GDROM_HARD_SECTOR);
739 	/* using DMA so memory will need to be contiguous */
740 	blk_queue_max_hw_segments(gd.gdrom_rq, 1);
741 	/* set a large max size to get most from DMA */
742 	blk_queue_max_segment_size(gd.gdrom_rq, 0x40000);
743 	gd.disk->queue = gd.gdrom_rq;
744 	return gdrom_init_dma_mode();
745 }
746 
747 /*
748  * register this as a block device and as compliant with the
749  * universal CD Rom driver interface
750  */
751 static int __devinit probe_gdrom(struct platform_device *devptr)
752 {
753 	int err;
754 	/* Start the device */
755 	if (gdrom_execute_diagnostic() != 1) {
756 		printk(KERN_WARNING "GDROM: 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 	printk(KERN_INFO "GDROM: 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 	gd.disk = alloc_disk(1);
776 	if (!gd.disk) {
777 		err = -ENODEV;
778 		goto probe_fail_no_disk;
779 	}
780 	probe_gdrom_setupdisk();
781 	if (register_cdrom(gd.cd_info)) {
782 		err = -ENODEV;
783 		goto probe_fail_cdrom_register;
784 	}
785 	gd.disk->fops = &gdrom_bdops;
786 	/* latch on to the interrupt */
787 	err = gdrom_set_interrupt_handlers();
788 	if (err)
789 		goto probe_fail_cmdirq_register;
790 	gd.gdrom_rq = blk_init_queue(gdrom_request, &gdrom_lock);
791 	if (!gd.gdrom_rq)
792 		goto probe_fail_requestq;
793 
794 	err = probe_gdrom_setupqueue();
795 	if (err)
796 		goto probe_fail_toc;
797 
798 	gd.toc = kzalloc(sizeof(struct gdromtoc), GFP_KERNEL);
799 	if (!gd.toc)
800 		goto probe_fail_toc;
801 	add_disk(gd.disk);
802 	return 0;
803 
804 probe_fail_toc:
805 	blk_cleanup_queue(gd.gdrom_rq);
806 probe_fail_requestq:
807 	free_irq(HW_EVENT_GDROM_DMA, &gd);
808 	free_irq(HW_EVENT_GDROM_CMD, &gd);
809 probe_fail_cmdirq_register:
810 probe_fail_cdrom_register:
811 	del_gendisk(gd.disk);
812 probe_fail_no_disk:
813 	kfree(gd.cd_info);
814 	unregister_blkdev(gdrom_major, GDROM_DEV_NAME);
815 	gdrom_major = 0;
816 probe_fail_no_mem:
817 	printk(KERN_WARNING "GDROM: Probe failed - error is 0x%X\n", err);
818 	return err;
819 }
820 
821 static int __devexit remove_gdrom(struct platform_device *devptr)
822 {
823 	flush_scheduled_work();
824 	blk_cleanup_queue(gd.gdrom_rq);
825 	free_irq(HW_EVENT_GDROM_CMD, &gd);
826 	free_irq(HW_EVENT_GDROM_DMA, &gd);
827 	del_gendisk(gd.disk);
828 	if (gdrom_major)
829 		unregister_blkdev(gdrom_major, GDROM_DEV_NAME);
830 	return unregister_cdrom(gd.cd_info);
831 }
832 
833 static struct platform_driver gdrom_driver = {
834 	.probe = probe_gdrom,
835 	.remove = __devexit_p(remove_gdrom),
836 	.driver = {
837 			.name = GDROM_DEV_NAME,
838 	},
839 };
840 
841 static int __init init_gdrom(void)
842 {
843 	int rc;
844 	gd.toc = NULL;
845 	rc = platform_driver_register(&gdrom_driver);
846 	if (rc)
847 		return rc;
848 	pd = platform_device_register_simple(GDROM_DEV_NAME, -1, NULL, 0);
849 	if (IS_ERR(pd)) {
850 		platform_driver_unregister(&gdrom_driver);
851 		return PTR_ERR(pd);
852 	}
853 	return 0;
854 }
855 
856 static void __exit exit_gdrom(void)
857 {
858 	platform_device_unregister(pd);
859 	platform_driver_unregister(&gdrom_driver);
860 	kfree(gd.toc);
861 }
862 
863 module_init(init_gdrom);
864 module_exit(exit_gdrom);
865 MODULE_AUTHOR("Adrian McMenamin <adrian@mcmen.demon.co.uk>");
866 MODULE_DESCRIPTION("SEGA Dreamcast GD-ROM Driver");
867 MODULE_LICENSE("GPL");
868