summaryrefslogtreecommitdiffstats
path: root/drivers/block/paride/pd.c
blob: c98983be4f9c088bcd3ebb2e98e1462a7dc6fbda (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
/* 
        pd.c    (c) 1997-8  Grant R. Guenther <grant@torque.net>
                            Under the terms of the GNU General Public License.

        This is the high-level driver for parallel port IDE hard
        drives based on chips supported by the paride module.

	By default, the driver will autoprobe for a single parallel
	port IDE drive, but if their individual parameters are
        specified, the driver can handle up to 4 drives.

        The behaviour of the pd driver can be altered by setting
        some parameters from the insmod command line.  The following
        parameters are adjustable:
 
	    drive0  	These four arguments can be arrays of	    
	    drive1	1-8 integers as follows:
	    drive2
	    drive3	<prt>,<pro>,<uni>,<mod>,<geo>,<sby>,<dly>,<slv>

			Where,

		<prt>	is the base of the parallel port address for
			the corresponding drive.  (required)

		<pro>   is the protocol number for the adapter that
			supports this drive.  These numbers are
                        logged by 'paride' when the protocol modules
			are initialised.  (0 if not given)

		<uni>   for those adapters that support chained
			devices, this is the unit selector for the
		        chain of devices on the given port.  It should
			be zero for devices that don't support chaining.
			(0 if not given)

		<mod>   this can be -1 to choose the best mode, or one
		        of the mode numbers supported by the adapter.
			(-1 if not given)

		<geo>   this defaults to 0 to indicate that the driver
			should use the CHS geometry provided by the drive
			itself.  If set to 1, the driver will provide
			a logical geometry with 64 heads and 32 sectors
			per track, to be consistent with most SCSI
		        drivers.  (0 if not given)

		<sby>   set this to zero to disable the power saving
			standby mode, if needed.  (1 if not given)

		<dly>   some parallel ports require the driver to 
			go more slowly.  -1 sets a default value that
			should work with the chosen protocol.  Otherwise,
			set this to a small integer, the larger it is
			the slower the port i/o.  In some cases, setting
			this to zero will speed up the device. (default -1)

		<slv>   IDE disks can be jumpered to master or slave.
                        Set this to 0 to choose the master drive, 1 to
                        choose the slave, -1 (the default) to choose the
                        first drive found.
			

            major       You may use this parameter to override the
                        default major number (45) that this driver
                        will use.  Be sure to change the device
                        name as well.

            name        This parameter is a character string that
                        contains the name the kernel will use for this
                        device (in /proc output, for instance).
			(default "pd")

	    cluster	The driver will attempt to aggregate requests
			for adjacent blocks into larger multi-block
			clusters.  The maximum cluster size (in 512
			byte sectors) is set with this parameter.
			(default 64)

	    verbose	This parameter controls the amount of logging
			that the driver will do.  Set it to 0 for 
			normal operation, 1 to see autoprobe progress
			messages, or 2 to see additional debugging
			output.  (default 0)

            nice        This parameter controls the driver's use of
                        idle CPU time, at the expense of some speed.

        If this driver is built into the kernel, you can use kernel
        the following command line parameters, with the same values
        as the corresponding module parameters listed above:

            pd.drive0
            pd.drive1
            pd.drive2
            pd.drive3
            pd.cluster
            pd.nice

        In addition, you can use the parameter pd.disable to disable
        the driver entirely.
 
*/

/* Changes:

	1.01	GRG 1997.01.24	Restored pd_reset()
				Added eject ioctl
	1.02    GRG 1998.05.06  SMP spinlock changes, 
				Added slave support
	1.03    GRG 1998.06.16  Eliminate an Ugh.
	1.04	GRG 1998.08.15  Extra debugging, use HZ in loop timing
	1.05    GRG 1998.09.24  Added jumbo support

*/

#define PD_VERSION      "1.05"
#define PD_MAJOR	45
#define PD_NAME		"pd"
#define PD_UNITS	4

/* Here are things one can override from the insmod command.
   Most are autoprobed by paride unless set here.  Verbose is off
   by default.

*/
#include <linux/types.h>

static int verbose = 0;
static int major = PD_MAJOR;
static char *name = PD_NAME;
static int cluster = 64;
static int nice = 0;
static int disable = 0;

static int drive0[8] = { 0, 0, 0, -1, 0, 1, -1, -1 };
static int drive1[8] = { 0, 0, 0, -1, 0, 1, -1, -1 };
static int drive2[8] = { 0, 0, 0, -1, 0, 1, -1, -1 };
static int drive3[8] = { 0, 0, 0, -1, 0, 1, -1, -1 };

static int (*drives[4])[8] = {&drive0, &drive1, &drive2, &drive3};

enum {D_PRT, D_PRO, D_UNI, D_MOD, D_GEO, D_SBY, D_DLY, D_SLV};

/* end of parameters */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/gfp.h>
#include <linux/fs.h>
#include <linux/delay.h>
#include <linux/hdreg.h>
#include <linux/cdrom.h>	/* for the eject ioctl */
#include <linux/blkdev.h>
#include <linux/blkpg.h>
#include <linux/kernel.h>
#include <linux/mutex.h>
#include <linux/uaccess.h>
#include <linux/workqueue.h>

static DEFINE_MUTEX(pd_mutex);
static DEFINE_SPINLOCK(pd_lock);

module_param(verbose, int, 0);
module_param(major, int, 0);
module_param(name, charp, 0);
module_param(cluster, int, 0);
module_param(nice, int, 0);
module_param_array(drive0, int, NULL, 0);
module_param_array(drive1, int, NULL, 0);
module_param_array(drive2, int, NULL, 0);
module_param_array(drive3, int, NULL, 0);

#include "paride.h"

#define PD_BITS    4

/* numbers for "SCSI" geometry */

#define PD_LOG_HEADS    64
#define PD_LOG_SECTS    32

#define PD_ID_OFF       54
#define PD_ID_LEN       14

#define PD_MAX_RETRIES  5
#define PD_TMO          800	/* interrupt timeout in jiffies */
#define PD_SPIN_DEL     50	/* spin delay in micro-seconds  */

#define PD_SPIN         (1000000*PD_TMO)/(HZ*PD_SPIN_DEL)

#define STAT_ERR        0x00001
#define STAT_INDEX      0x00002
#define STAT_ECC        0x00004
#define STAT_DRQ        0x00008
#define STAT_SEEK       0x00010
#define STAT_WRERR      0x00020
#define STAT_READY      0x00040
#define STAT_BUSY       0x00080

#define ERR_AMNF        0x00100
#define ERR_TK0NF       0x00200
#define ERR_ABRT        0x00400
#define ERR_MCR         0x00800
#define ERR_IDNF        0x01000
#define ERR_MC          0x02000
#define ERR_UNC         0x04000
#define ERR_TMO         0x10000

#define IDE_READ        	0x20
#define IDE_WRITE       	0x30
#define IDE_READ_VRFY		0x40
#define IDE_INIT_DEV_PARMS	0x91
#define IDE_STANDBY     	0x96
#define IDE_ACKCHANGE   	0xdb
#define IDE_DOORLOCK    	0xde
#define IDE_DOORUNLOCK  	0xdf
#define IDE_IDENTIFY    	0xec
#define IDE_EJECT		0xed

#define PD_NAMELEN	8

struct pd_unit {
	struct pi_adapter pia;	/* interface to paride layer */
	struct pi_adapter *pi;
	int access;		/* count of active opens ... */
	int capacity;		/* Size of this volume in sectors */
	int heads;		/* physical geometry */
	int sectors;
	int cylinders;
	int can_lba;
	int drive;		/* master=0 slave=1 */
	int changed;		/* Have we seen a disk change ? */
	int removable;		/* removable media device  ?  */
	int standby;
	int alt_geom;
	char name[PD_NAMELEN];	/* pda, pdb, etc ... */
	struct gendisk *gd;
};

static struct pd_unit pd[PD_UNITS];

static char pd_scratch[512];	/* scratch block buffer */

static char *pd_errs[17] = { "ERR", "INDEX", "ECC", "DRQ", "SEEK", "WRERR",
	"READY", "BUSY", "AMNF", "TK0NF", "ABRT", "MCR",
	"IDNF", "MC", "UNC", "???", "TMO"
};

static void *par_drv;		/* reference of parport driver */

static inline int status_reg(struct pd_unit *disk)
{
	return pi_read_regr(disk->pi, 1, 6);
}

static inline int read_reg(struct pd_unit *disk, int reg)
{
	return pi_read_regr(disk->pi, 0, reg);
}

static inline void write_status(struct pd_unit *disk, int val)
{
	pi_write_regr(disk->pi, 1, 6, val);
}

static inline void write_reg(struct pd_unit *disk, int reg, int val)
{
	pi_write_regr(disk->pi, 0, reg, val);
}

static inline u8 DRIVE(struct pd_unit *disk)
{
	return 0xa0+0x10*disk->drive;
}

/*  ide command interface */

static void pd_print_error(struct pd_unit *disk, char *msg, int status)
{
	int i;

	printk("%s: %s: status = 0x%x =", disk->name, msg, status);
	for (i = 0; i < ARRAY_SIZE(pd_errs); i++)
		if (status & (1 << i))
			printk(" %s", pd_errs[i]);
	printk("\n");
}

static void pd_reset(struct pd_unit *disk)
{				/* called only for MASTER drive */
	write_status(disk, 4);
	udelay(50);
	write_status(disk, 0);
	udelay(250);
}

#define DBMSG(msg)	((verbose>1)?(msg):NULL)

static int pd_wait_for(struct pd_unit *disk, int w, char *msg)
{				/* polled wait */
	int k, r, e;

	k = 0;
	while (k < PD_SPIN) {
		r = status_reg(disk);
		k++;
		if (((r & w) == w) && !(r & STAT_BUSY))
			break;
		udelay(PD_SPIN_DEL);
	}
	e = (read_reg(disk, 1) << 8) + read_reg(disk, 7);
	if (k >= PD_SPIN)
		e |= ERR_TMO;
	if ((e & (STAT_ERR | ERR_TMO)) && (msg != NULL))
		pd_print_error(disk, msg, e);
	return e;
}

static void pd_send_command(struct pd_unit *disk, int n, int s, int h, int c0, int c1, int func)
{
	write_reg(disk, 6, DRIVE(disk) + h);
	write_reg(disk, 1, 0);		/* the IDE task file */
	write_reg(disk, 2, n);
	write_reg(disk, 3, s);
	write_reg(disk, 4, c0);
	write_reg(disk, 5, c1);
	write_reg(disk, 7, func);

	udelay(1);
}

static void pd_ide_command(struct pd_unit *disk, int func, int block, int count)
{
	int c1, c0, h, s;

	if (disk->can_lba) {
		s = block & 255;
		c0 = (block >>= 8) & 255;
		c1 = (block >>= 8) & 255;
		h = ((block >>= 8) & 15) + 0x40;
	} else {
		s = (block % disk->sectors) + 1;
		h = (block /= disk->sectors) % disk->heads;
		c0 = (block /= disk->heads) % 256;
		c1 = (block >>= 8);
	}
	pd_send_command(disk, count, s, h, c0, c1, func);
}

/* The i/o request engine */

enum action {Fail = 0, Ok = 1, Hold, Wait};

static struct request *pd_req;	/* current request */
static enum action (*phase)(void);

static void run_fsm(void);

static void ps_tq_int(struct work_struct *work);

static DECLARE_DELAYED_WORK(fsm_tq, ps_tq_int);

static void schedule_fsm(void)
{
	if (!nice)
		schedule_delayed_work(&fsm_tq, 0);
	else
		schedule_delayed_work(&fsm_tq, nice-1);
}

static void ps_tq_int(struct work_struct *work)
{
	run_fsm();
}

static enum action do_pd_io_start(void);
static enum action pd_special(void);
static enum action do_pd_read_start(void);
static enum action do_pd_write_start(void);
static enum action do_pd_read_drq(void);
static enum action do_pd_write_done(void);

static int pd_queue;
static int pd_claimed;

static struct pd_unit *pd_current; /* current request's drive */
static PIA *pi_current; /* current request's PIA */

static int set_next_request(void)
{
	struct gendisk *disk;
	struct request_queue *q;
	int old_pos = pd_queue;

	do {
		disk = pd[pd_queue].gd;
		q = disk ? disk->queue : NULL;
		if (++pd_queue == PD_UNITS)
			pd_queue = 0;
		if (q) {
			pd_req = blk_fetch_request(q);
			if (pd_req)
				break;
		}
	} while (pd_queue != old_pos);

	return pd_req != NULL;
}

static void run_fsm(void)
{
	while (1) {
		enum action res;
		unsigned long saved_flags;
		int stop = 0;

		if (!phase) {
			pd_current = pd_req->rq_disk->private_data;
			pi_current = pd_current->pi;
			phase = do_pd_io_start;
		}

		switch (pd_claimed) {
			case 0:
				pd_claimed = 1;
				if (!pi_schedule_claimed(pi_current, run_fsm))
					return;
			case 1:
				pd_claimed = 2;
				pi_current->proto->connect(pi_current);
		}

		switch(res = phase()) {
			case Ok: case Fail:
				pi_disconnect(pi_current);
				pd_claimed = 0;
				phase = NULL;
				spin_lock_irqsave(&pd_lock, saved_flags);
				if (!__blk_end_request_cur(pd_req,
						res == Ok ? 0 : BLK_STS_IOERR)) {
					if (!set_next_request())
						stop = 1;
				}
				spin_unlock_irqrestore(&pd_lock, saved_flags);
				if (stop)
					return;
			case Hold:
				schedule_fsm();
				return;
			case Wait:
				pi_disconnect(pi_current);
				pd_claimed = 0;
		}
	}
}

static int pd_retries = 0;	/* i/o error retry count */
static int pd_block;		/* address of next requested block */
static int pd_count;		/* number of blocks still to do */
static int pd_run;		/* sectors in current cluster */
static char *pd_buf;		/* buffer for request in progress */

static enum action do_pd_io_start(void)
{
	switch (req_op(pd_req)) {
	case REQ_OP_DRV_IN:
		phase = pd_special;
		return pd_special();
	case REQ_OP_READ:
	case REQ_OP_WRITE:
		pd_block = blk_rq_pos(pd_req);
		pd_count = blk_rq_cur_sectors(pd_req);
		if (pd_block + pd_count > get_capacity(pd_req->rq_disk))
			return Fail;
		pd_run = blk_rq_sectors(pd_req);
		pd_buf = bio_data(pd_req->bio);
		pd_retries = 0;
		if (req_op(pd_req) == REQ_OP_READ)
			return do_pd_read_start();
		else
			return do_pd_write_start();
	}
	return Fail;
}

static enum action pd_special(void)
{
	enum action (*func)(struct pd_unit *) = pd_req->special;
	return func(pd_current);
}

static int pd_next_buf(void)
{
	unsigned long saved_flags;

	pd_count--;
	pd_run--;
	pd_buf += 512;
	pd_block++;
	if (!pd_run)
		return 1;
	if (pd_count)
		return 0;
	spin_lock_irqsave(&pd_lock, saved_flags);
	__blk_end_request_cur(pd_req, 0);
	pd_count = blk_rq_cur_sectors(pd_req);
	pd_buf = bio_data(pd_req->bio);
	spin_unlock_irqrestore(&pd_lock, saved_flags);
	return 0;
}

static unsigned long pd_timeout;

static enum action do_pd_read_start(void)
{
	if (pd_wait_for(pd_current, STAT_READY, "do_pd_read") & STAT_ERR) {
		if (pd_retries < PD_MAX_RETRIES) {
			pd_retries++;
			return Wait;
		}
		return Fail;
	}
	pd_ide_command(pd_current, IDE_READ, pd_block, pd_run);
	phase = do_pd_read_drq;
	pd_timeout = jiffies + PD_TMO;
	return Hold;
}

static enum action do_pd_write_start(void)
{
	if (pd_wait_for(pd_current, STAT_READY, "do_pd_write") & STAT_ERR) {
		if (pd_retries < PD_MAX_RETRIES) {
			pd_retries++;
			return Wait;
		}
		return Fail;
	}
	pd_ide_command(pd_current, IDE_WRITE, pd_block, pd_run);
	while (1) {
		if (pd_wait_for(pd_current, STAT_DRQ, "do_pd_write_drq") & STAT_ERR) {
			if (pd_retries < PD_MAX_RETRIES) {
				pd_retries++;
				return Wait;
			}
			return Fail;
		}
		pi_write_block(pd_current->pi, pd_buf, 512);
		if (pd_next_buf())
			break;
	}
	phase = do_pd_write_done;
	pd_timeout = jiffies + PD_TMO;
	return Hold;
}

static inline int pd_ready(void)
{
	return !(status_reg(pd_current) & STAT_BUSY);
}

static enum action do_pd_read_drq(void)
{
	if (!pd_ready() && !time_after_eq(jiffies, pd_timeout))
		return Hold;

	while (1) {
		if (pd_wait_for(pd_current, STAT_DRQ, "do_pd_read_drq") & STAT_ERR) {
			if (pd_retries < PD_MAX_RETRIES) {
				pd_retries++;
				phase = do_pd_read_start;
				return Wait;
			}
			return Fail;
		}
		pi_read_block(pd_current->pi, pd_buf, 512);
		if (pd_next_buf())
			break;
	}
	return Ok;
}

static enum action do_pd_write_done(void)
{
	if (!pd_ready() && !time_after_eq(jiffies, pd_timeout))
		return Hold;

	if (pd_wait_for(pd_current, STAT_READY, "do_pd_write_done") & STAT_ERR) {
		if (pd_retries < PD_MAX_RETRIES) {
			pd_retries++;
			phase = do_pd_write_start;
			return Wait;
		}
		return Fail;
	}
	return Ok;
}

/* special io requests */

/* According to the ATA standard, the default CHS geometry should be
   available following a reset.  Some Western Digital drives come up
   in a mode where only LBA addresses are accepted until the device
   parameters are initialised.
*/

static void pd_init_dev_parms(struct pd_unit *disk)
{
	pd_wait_for(disk, 0, DBMSG("before init_dev_parms"));
	pd_send_command(disk, disk->sectors, 0, disk->heads - 1, 0, 0,
			IDE_INIT_DEV_PARMS);
	udelay(300);
	pd_wait_for(disk, 0, "Initialise device parameters");
}

static enum action pd_door_lock(struct pd_unit *disk)
{
	if (!(pd_wait_for(disk, STAT_READY, "Lock") & STAT_ERR)) {
		pd_send_command(disk, 1, 0, 0, 0, 0, IDE_DOORLOCK);
		pd_wait_for(disk, STAT_READY, "Lock done");
	}
	return Ok;
}

static enum action pd_door_unlock(struct pd_unit *disk)
{
	if (!(pd_wait_for(disk, STAT_READY, "Lock") & STAT_ERR)) {
		pd_send_command(disk, 1, 0, 0, 0, 0, IDE_DOORUNLOCK);
		pd_wait_for(disk, STAT_READY, "Lock done");
	}
	return Ok;
}

static enum action pd_eject(struct pd_unit *disk)
{
	pd_wait_for(disk, 0, DBMSG("before unlock on eject"));
	pd_send_command(disk, 1, 0, 0, 0, 0, IDE_DOORUNLOCK);
	pd_wait_for(disk, 0, DBMSG("after unlock on eject"));
	pd_wait_for(disk, 0, DBMSG("before eject"));
	pd_send_command(disk, 0, 0, 0, 0, 0, IDE_EJECT);
	pd_wait_for(disk, 0, DBMSG("after eject"));
	return Ok;
}

static enum action pd_media_check(struct pd_unit *disk)
{
	int r = pd_wait_for(disk, STAT_READY, DBMSG("before media_check"));
	if (!(r & STAT_ERR)) {
		pd_send_command(disk, 1, 1, 0, 0, 0, IDE_READ_VRFY);
		r = pd_wait_for(disk, STAT_READY, DBMSG("RDY after READ_VRFY"));
	} else
		disk->changed = 1;	/* say changed if other error */
	if (r & ERR_MC) {
		disk->changed = 1;
		pd_send_command(disk, 1, 0, 0, 0, 0, IDE_ACKCHANGE);
		pd_wait_for(disk, STAT_READY, DBMSG("RDY after ACKCHANGE"));
		pd_send_command(disk, 1, 1, 0, 0, 0, IDE_READ_VRFY);
		r = pd_wait_for(disk, STAT_READY, DBMSG("RDY after VRFY"));
	}
	return Ok;
}

static void pd_standby_off(struct pd_unit *disk)
{
	pd_wait_for(disk, 0, DBMSG("before STANDBY"));
	pd_send_command(disk, 0, 0, 0, 0, 0, IDE_STANDBY);
	pd_wait_for(disk, 0, DBMSG("after STANDBY"));
}

static enum action pd_identify(struct pd_unit *disk)
{
	int j;
	char id[PD_ID_LEN + 1];

/* WARNING:  here there may be dragons.  reset() applies to both drives,
   but we call it only on probing the MASTER. This should allow most
   common configurations to work, but be warned that a reset can clear
   settings on the SLAVE drive.
*/

	if (disk->drive == 0)
		pd_reset(disk);

	write_reg(disk, 6, DRIVE(disk));
	pd_wait_for(disk, 0, DBMSG("before IDENT"));
	pd_send_command(disk, 1, 0, 0, 0, 0, IDE_IDENTIFY);

	if (pd_wait_for(disk, STAT_DRQ, DBMSG("IDENT DRQ")) & STAT_ERR)
		return Fail;
	pi_read_block(disk->pi, pd_scratch, 512);
	disk->can_lba = pd_scratch[99] & 2;
	disk->sectors = le16_to_cpu(*(__le16 *) (pd_scratch + 12));
	disk->heads = le16_to_cpu(*(__le16 *) (pd_scratch + 6));
	disk->cylinders = le16_to_cpu(*(__le16 *) (pd_scratch + 2));
	if (disk->can_lba)
		disk->capacity = le32_to_cpu(*(__le32 *) (pd_scratch + 120));
	else
		disk->capacity = disk->sectors * disk->heads * disk->cylinders;

	for (j = 0; j < PD_ID_LEN; j++)
		id[j ^ 1] = pd_scratch[j + PD_ID_OFF];
	j = PD_ID_LEN - 1;
	while ((j >= 0) && (id[j] <= 0x20))
		j--;
	j++;
	id[j] = 0;

	disk->removable = pd_scratch[0] & 0x80;

	printk("%s: %s, %s, %d blocks [%dM], (%d/%d/%d), %s media\n",
	       disk->name, id,
	       disk->drive ? "slave" : "master",
	       disk->capacity, disk->capacity / 2048,
	       disk->cylinders, disk->heads, disk->sectors,
	       disk->removable ? "removable" : "fixed");

	if (disk->capacity)
		pd_init_dev_parms(disk);
	if (!disk->standby)
		pd_standby_off(disk);

	return Ok;
}

/* end of io request engine */

static void do_pd_request(struct request_queue * q)
{
	if (pd_req)
		return;
	pd_req = blk_fetch_request(q);
	if (!pd_req)
		return;

	schedule_fsm();
}

static int pd_special_command(struct pd_unit *disk,
		      enum action (*func)(struct pd_unit *disk))
{
	struct request *rq;

	rq = blk_get_request(disk->gd->queue, REQ_OP_DRV_IN, __GFP_RECLAIM);
	if (IS_ERR(rq))
		return PTR_ERR(rq);

	rq->special = func;
	blk_execute_rq(disk->gd->queue, disk->gd, rq, 0);
	blk_put_request(rq);
	return 0;
}

/* kernel glue structures */

static int pd_open(struct block_device *bdev, fmode_t mode)
{
	struct pd_unit *disk = bdev->bd_disk->private_data;

	mutex_lock(&pd_mutex);
	disk->access++;

	if (disk->removable) {
		pd_special_command(disk, pd_media_check);
		pd_special_command(disk, pd_door_lock);
	}
	mutex_unlock(&pd_mutex);
	return 0;
}

static int pd_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
	struct pd_unit *disk = bdev->bd_disk->private_data;

	if (disk->alt_geom) {
		geo->heads = PD_LOG_HEADS;
		geo->sectors = PD_LOG_SECTS;
		geo->cylinders = disk->capacity / (geo->heads * geo->sectors);
	} else {
		geo->heads = disk->heads;
		geo->sectors = disk->sectors;
		geo->cylinders = disk->cylinders;
	}

	return 0;
}

static int pd_ioctl(struct block_device *bdev, fmode_t mode,
	 unsigned int cmd, unsigned long arg)
{
	struct pd_unit *disk = bdev->bd_disk->private_data;

	switch (cmd) {
	case CDROMEJECT:
		mutex_lock(&pd_mutex);
		if (disk->access == 1)
			pd_special_command(disk, pd_eject);
		mutex_unlock(&pd_mutex);
		return 0;
	default:
		return -EINVAL;
	}
}

static void pd_release(struct gendisk *p, fmode_t mode)
{
	struct pd_unit *disk = p->private_data;

	mutex_lock(&pd_mutex);
	if (!--disk->access && disk->removable)
		pd_special_command(disk, pd_door_unlock);
	mutex_unlock(&pd_mutex);
}

static unsigned int pd_check_events(struct gendisk *p, unsigned int clearing)
{
	struct pd_unit *disk = p->private_data;
	int r;
	if (!disk->removable)
		return 0;
	pd_special_command(disk, pd_media_check);
	r = disk->changed;
	disk->changed = 0;
	return r ? DISK_EVENT_MEDIA_CHANGE : 0;
}

static int pd_revalidate(struct gendisk *p)
{
	struct pd_unit *disk = p->private_data;
	if (pd_special_command(disk, pd_identify) == 0)
		set_capacity(p, disk->capacity);
	else
		set_capacity(p, 0);
	return 0;
}

static const struct block_device_operations pd_fops = {
	.owner		= THIS_MODULE,
	.open		= pd_open,
	.release	= pd_release,
	.ioctl		= pd_ioctl,
	.getgeo		= pd_getgeo,
	.check_events	= pd_check_events,
	.revalidate_disk= pd_revalidate
};

/* probing */

static void pd_probe_drive(struct pd_unit *disk)
{
	struct gendisk *p = alloc_disk(1 << PD_BITS);
	if (!p)
		return;
	strcpy(p->disk_name, disk->name);
	p->fops = &pd_fops;
	p->major = major;
	p->first_minor = (disk - pd) << PD_BITS;
	disk->gd = p;
	p->private_data = disk;
	p->queue = blk_init_queue(do_pd_request, &pd_lock);
	if (!p->queue) {
		disk->gd = NULL;
		put_disk(p);
		return;
	}
	blk_queue_max_hw_sectors(p->queue, cluster);

	if (disk->drive == -1) {
		for (disk->drive = 0; disk->drive <= 1; disk->drive++)
			if (pd_special_command(disk, pd_identify) == 0)
				return;
	} else if (pd_special_command(disk, pd_identify) == 0)
		return;
	disk->gd = NULL;
	put_disk(p);
}

static int pd_detect(void)
{
	int found = 0, unit, pd_drive_count = 0;
	struct pd_unit *disk;

	for (unit = 0; unit < PD_UNITS; unit++) {
		int *parm = *drives[unit];
		struct pd_unit *disk = pd + unit;
		disk->pi = &disk->pia;
		disk->access = 0;
		disk->changed = 1;
		disk->capacity = 0;
		disk->drive = parm[D_SLV];
		snprintf(disk->name, PD_NAMELEN, "%s%c", name, 'a'+unit);
		disk->alt_geom = parm[D_GEO];
		disk->standby = parm[D_SBY];
		if (parm[D_PRT])
			pd_drive_count++;
	}

	par_drv = pi_register_driver(name);
	if (!par_drv) {
		pr_err("failed to register %s driver\n", name);
		return -1;
	}

	if (pd_drive_count == 0) { /* nothing spec'd - so autoprobe for 1 */
		disk = pd;
		if (pi_init(disk->pi, 1, -1, -1, -1, -1, -1, pd_scratch,
			    PI_PD, verbose, disk->name)) {
			pd_probe_drive(disk);
			if (!disk->gd)
				pi_release(disk->pi);
		}

	} else {
		for (unit = 0, disk = pd; unit < PD_UNITS; unit++, disk++) {
			int *parm = *drives[unit];
			if (!parm[D_PRT])
				continue;
			if (pi_init(disk->pi, 0, parm[D_PRT], parm[D_MOD],
				     parm[D_UNI], parm[D_PRO], parm[D_DLY],
				     pd_scratch, PI_PD, verbose, disk->name)) {
				pd_probe_drive(disk);
				if (!disk->gd)
					pi_release(disk->pi);
			}
		}
	}
	for (unit = 0, disk = pd; unit < PD_UNITS; unit++, disk++) {
		if (disk->gd) {
			set_capacity(disk->gd, disk->capacity);
			add_disk(disk->gd);
			found = 1;
		}
	}
	if (!found) {
		printk("%s: no valid drive found\n", name);
		pi_unregister_driver(par_drv);
	}
	return found;
}

static int __init pd_init(void)
{
	if (disable)
		goto out1;

	if (register_blkdev(major, name))
		goto out1;

	printk("%s: %s version %s, major %d, cluster %d, nice %d\n",
	       name, name, PD_VERSION, major, cluster, nice);
	if (!pd_detect())
		goto out2;

	return 0;

out2:
	unregister_blkdev(major, name);
out1:
	return -ENODEV;
}

static void __exit pd_exit(void)
{
	struct pd_unit *disk;
	int unit;
	unregister_blkdev(major, name);
	for (unit = 0, disk = pd; unit < PD_UNITS; unit++, disk++) {
		struct gendisk *p = disk->gd;
		if (p) {
			disk->gd = NULL;
			del_gendisk(p);
			blk_cleanup_queue(p->queue);
			put_disk(p);
			pi_release(disk->pi);
		}
	}
}

MODULE_LICENSE("GPL");
module_init(pd_init)
module_exit(pd_exit)