aboutsummaryrefslogtreecommitdiff
path: root/drivers/block/paride/pf.c
blob: a902d84fd33083f6ed6651bfee616340ecf1a533 (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
981
982
983
984
985
986
987
988
989
990
991
992
/* 
        pf.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 ATAPI disk
        drives based on chips supported by the paride module.

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

        The behaviour of the pf 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      1-7 integers as follows:
            drive2
            drive3      <prt>,<pro>,<uni>,<mod>,<slv>,<lun>,<dly>

                        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)

                <slv>   ATAPI CDroms 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.

		<lun>   Some ATAPI devices support multiple LUNs.
                        One example is the ATAPI PD/CD drive from
                        Matshita/Panasonic.  This device has a 
                        CD drive on LUN 0 and a PD drive on LUN 1.
                        By default, the driver will search for the
                        first LUN with a supported device.  Set 
                        this parameter to force it to use a specific
                        LUN.  (default -1)

                <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)

	    major	You may use this parameter to overide the
			default major number (47) 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 "pf").

            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 the
        following command line parameters, with the same values
        as the corresponding module parameters listed above:

            pf.drive0
            pf.drive1
            pf.drive2
            pf.drive3
	    pf.cluster
            pf.nice

        In addition, you can use the parameter pf.disable to disable
        the driver entirely.

*/

/* Changes:

	1.01	GRG 1998.05.03  Changes for SMP.  Eliminate sti().
				Fix for drives that don't clear STAT_ERR
			        until after next CDB delivered.
				Small change in pf_completion to round
				up transfer size.
	1.02    GRG 1998.06.16  Eliminated an Ugh
	1.03    GRG 1998.08.16  Use HZ in loop timings, extra debugging
	1.04    GRG 1998.09.24  Added jumbo support

*/

#define PF_VERSION      "1.04"
#define PF_MAJOR	47
#define PF_NAME		"pf"
#define PF_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.

*/

static int verbose = 0;
static int major = PF_MAJOR;
static char *name = PF_NAME;
static int cluster = 64;
static int nice = 0;
static int disable = 0;

static int drive0[7] = { 0, 0, 0, -1, -1, -1, -1 };
static int drive1[7] = { 0, 0, 0, -1, -1, -1, -1 };
static int drive2[7] = { 0, 0, 0, -1, -1, -1, -1 };
static int drive3[7] = { 0, 0, 0, -1, -1, -1, -1 };

static int (*drives[4])[7] = {&drive0, &drive1, &drive2, &drive3};
static int pf_drive_count;

enum {D_PRT, D_PRO, D_UNI, D_MOD, D_SLV, D_LUN, D_DLY};

/* end of parameters */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/fs.h>
#include <linux/delay.h>
#include <linux/hdreg.h>
#include <linux/cdrom.h>
#include <linux/spinlock.h>
#include <linux/blkdev.h>
#include <linux/blkpg.h>
#include <asm/uaccess.h>

static DEFINE_SPINLOCK(pf_spin_lock);

module_param(verbose, bool, 0644);
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"
#include "pseudo.h"

/* constants for faking geometry numbers */

#define PF_FD_MAX	8192	/* use FD geometry under this size */
#define PF_FD_HDS	2
#define PF_FD_SPT	18
#define PF_HD_HDS	64
#define PF_HD_SPT	32

#define PF_MAX_RETRIES  5
#define PF_TMO          800	/* interrupt timeout in jiffies */
#define PF_SPIN_DEL     50	/* spin delay in micro-seconds  */

#define PF_SPIN         (1000000*PF_TMO)/(HZ*PF_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 ATAPI_REQ_SENSE		0x03
#define ATAPI_LOCK		0x1e
#define ATAPI_DOOR		0x1b
#define ATAPI_MODE_SENSE	0x5a
#define ATAPI_CAPACITY		0x25
#define ATAPI_IDENTIFY		0x12
#define ATAPI_READ_10		0x28
#define ATAPI_WRITE_10		0x2a

static int pf_open(struct inode *inode, struct file *file);
static void do_pf_request(struct request_queue * q);
static int pf_ioctl(struct inode *inode, struct file *file,
		    unsigned int cmd, unsigned long arg);
static int pf_getgeo(struct block_device *bdev, struct hd_geometry *geo);

static int pf_release(struct inode *inode, struct file *file);

static int pf_detect(void);
static void do_pf_read(void);
static void do_pf_read_start(void);
static void do_pf_write(void);
static void do_pf_write_start(void);
static void do_pf_read_drq(void);
static void do_pf_write_done(void);

#define PF_NM           0
#define PF_RO           1
#define PF_RW           2

#define PF_NAMELEN      8

struct pf_unit {
	struct pi_adapter pia;	/* interface to paride layer */
	struct pi_adapter *pi;
	int removable;		/* removable media device  ?  */
	int media_status;	/* media present ?  WP ? */
	int drive;		/* drive */
	int lun;
	int access;		/* count of active opens ... */
	int present;		/* device present ? */
	char name[PF_NAMELEN];	/* pf0, pf1, ... */
	struct gendisk *disk;
};

static struct pf_unit units[PF_UNITS];

static int pf_identify(struct pf_unit *pf);
static void pf_lock(struct pf_unit *pf, int func);
static void pf_eject(struct pf_unit *pf);
static int pf_check_media(struct gendisk *disk);

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

/* the variables below are used mainly in the I/O request engine, which
   processes only one request at a time.
*/

static int pf_retries = 0;	/* i/o error retry count */
static int pf_busy = 0;		/* request being processed ? */
static struct request *pf_req;	/* current request */
static int pf_block;		/* address of next requested block */
static int pf_count;		/* number of blocks still to do */
static int pf_run;		/* sectors in current cluster */
static int pf_cmd;		/* current command READ/WRITE */
static struct pf_unit *pf_current;/* unit of current request */
static int pf_mask;		/* stopper for pseudo-int */
static char *pf_buf;		/* buffer for request in progress */

/* kernel glue structures */

static struct block_device_operations pf_fops = {
	.owner		= THIS_MODULE,
	.open		= pf_open,
	.release	= pf_release,
	.ioctl		= pf_ioctl,
	.getgeo		= pf_getgeo,
	.media_changed	= pf_check_media,
};

static void __init pf_init_units(void)
{
	struct pf_unit *pf;
	int unit;

	pf_drive_count = 0;
	for (unit = 0, pf = units; unit < PF_UNITS; unit++, pf++) {
		struct gendisk *disk = alloc_disk(1);
		if (!disk)
			continue;
		pf->disk = disk;
		pf->pi = &pf->pia;
		pf->media_status = PF_NM;
		pf->drive = (*drives[unit])[D_SLV];
		pf->lun = (*drives[unit])[D_LUN];
		snprintf(pf->name, PF_NAMELEN, "%s%d", name, unit);
		disk->major = major;
		disk->first_minor = unit;
		strcpy(disk->disk_name, pf->name);
		disk->fops = &pf_fops;
		if (!(*drives[unit])[D_PRT])
			pf_drive_count++;
	}
}

static int pf_open(struct inode *inode, struct file *file)
{
	struct pf_unit *pf = inode->i_bdev->bd_disk->private_data;

	pf_identify(pf);

	if (pf->media_status == PF_NM)
		return -ENODEV;

	if ((pf->media_status == PF_RO) && (file->f_mode & FMODE_WRITE))
		return -EROFS;

	pf->access++;
	if (pf->removable)
		pf_lock(pf, 1);

	return 0;
}

static int pf_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
	struct pf_unit *pf = bdev->bd_disk->private_data;
	sector_t capacity = get_capacity(pf->disk);

	if (capacity < PF_FD_MAX) {
		geo->cylinders = sector_div(capacity, PF_FD_HDS * PF_FD_SPT);
		geo->heads = PF_FD_HDS;
		geo->sectors = PF_FD_SPT;
	} else {
		geo->cylinders = sector_div(capacity, PF_HD_HDS * PF_HD_SPT);
		geo->heads = PF_HD_HDS;
		geo->sectors = PF_HD_SPT;
	}

	return 0;
}

static int pf_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
	struct pf_unit *pf = inode->i_bdev->bd_disk->private_data;

	if (cmd != CDROMEJECT)
		return -EINVAL;

	if (pf->access != 1)
		return -EBUSY;
	pf_eject(pf);
	return 0;
}

static int pf_release(struct inode *inode, struct file *file)
{
	struct pf_unit *pf = inode->i_bdev->bd_disk->private_data;

	if (pf->access <= 0)
		return -EINVAL;

	pf->access--;

	if (!pf->access && pf->removable)
		pf_lock(pf, 0);

	return 0;

}

static int pf_check_media(struct gendisk *disk)
{
	return 1;
}

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

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

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

static int pf_wait(struct pf_unit *pf, int go, int stop, char *fun, char *msg)
{
	int j, r, e, s, p;

	j = 0;
	while ((((r = status_reg(pf)) & go) || (stop && (!(r & stop))))
	       && (j++ < PF_SPIN))
		udelay(PF_SPIN_DEL);

	if ((r & (STAT_ERR & stop)) || (j >= PF_SPIN)) {
		s = read_reg(pf, 7);
		e = read_reg(pf, 1);
		p = read_reg(pf, 2);
		if (j >= PF_SPIN)
			e |= 0x100;
		if (fun)
			printk("%s: %s %s: alt=0x%x stat=0x%x err=0x%x"
			       " loop=%d phase=%d\n",
			       pf->name, fun, msg, r, s, e, j, p);
		return (e << 8) + s;
	}
	return 0;
}

static int pf_command(struct pf_unit *pf, char *cmd, int dlen, char *fun)
{
	pi_connect(pf->pi);

	write_reg(pf, 6, 0xa0+0x10*pf->drive);

	if (pf_wait(pf, STAT_BUSY | STAT_DRQ, 0, fun, "before command")) {
		pi_disconnect(pf->pi);
		return -1;
	}

	write_reg(pf, 4, dlen % 256);
	write_reg(pf, 5, dlen / 256);
	write_reg(pf, 7, 0xa0);	/* ATAPI packet command */

	if (pf_wait(pf, STAT_BUSY, STAT_DRQ, fun, "command DRQ")) {
		pi_disconnect(pf->pi);
		return -1;
	}

	if (read_reg(pf, 2) != 1) {
		printk("%s: %s: command phase error\n", pf->name, fun);
		pi_disconnect(pf->pi);
		return -1;
	}

	pi_write_block(pf->pi, cmd, 12);

	return 0;
}

static int pf_completion(struct pf_unit *pf, char *buf, char *fun)
{
	int r, s, n;

	r = pf_wait(pf, STAT_BUSY, STAT_DRQ | STAT_READY | STAT_ERR,
		    fun, "completion");

	if ((read_reg(pf, 2) & 2) && (read_reg(pf, 7) & STAT_DRQ)) {
		n = (((read_reg(pf, 4) + 256 * read_reg(pf, 5)) +
		      3) & 0xfffc);
		pi_read_block(pf->pi, buf, n);
	}

	s = pf_wait(pf, STAT_BUSY, STAT_READY | STAT_ERR, fun, "data done");

	pi_disconnect(pf->pi);

	return (r ? r : s);
}

static void pf_req_sense(struct pf_unit *pf, int quiet)
{
	char rs_cmd[12] =
	    { ATAPI_REQ_SENSE, pf->lun << 5, 0, 0, 16, 0, 0, 0, 0, 0, 0, 0 };
	char buf[16];
	int r;

	r = pf_command(pf, rs_cmd, 16, "Request sense");
	mdelay(1);
	if (!r)
		pf_completion(pf, buf, "Request sense");

	if ((!r) && (!quiet))
		printk("%s: Sense key: %x, ASC: %x, ASQ: %x\n",
		       pf->name, buf[2] & 0xf, buf[12], buf[13]);
}

static int pf_atapi(struct pf_unit *pf, char *cmd, int dlen, char *buf, char *fun)
{
	int r;

	r = pf_command(pf, cmd, dlen, fun);
	mdelay(1);
	if (!r)
		r = pf_completion(pf, buf, fun);
	if (r)
		pf_req_sense(pf, !fun);

	return r;
}

static void pf_lock(struct pf_unit *pf, int func)
{
	char lo_cmd[12] = { ATAPI_LOCK, pf->lun << 5, 0, 0, func, 0, 0, 0, 0, 0, 0, 0 };

	pf_atapi(pf, lo_cmd, 0, pf_scratch, func ? "lock" : "unlock");
}

static void pf_eject(struct pf_unit *pf)
{
	char ej_cmd[12] = { ATAPI_DOOR, pf->lun << 5, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0 };

	pf_lock(pf, 0);
	pf_atapi(pf, ej_cmd, 0, pf_scratch, "eject");
}

#define PF_RESET_TMO   30	/* in tenths of a second */

static void pf_sleep(int cs)
{
	schedule_timeout_interruptible(cs);
}

/* the ATAPI standard actually specifies the contents of all 7 registers
   after a reset, but the specification is ambiguous concerning the last
   two bytes, and different drives interpret the standard differently.
 */

static int pf_reset(struct pf_unit *pf)
{
	int i, k, flg;
	int expect[5] = { 1, 1, 1, 0x14, 0xeb };

	pi_connect(pf->pi);
	write_reg(pf, 6, 0xa0+0x10*pf->drive);
	write_reg(pf, 7, 8);

	pf_sleep(20 * HZ / 1000);

	k = 0;
	while ((k++ < PF_RESET_TMO) && (status_reg(pf) & STAT_BUSY))
		pf_sleep(HZ / 10);

	flg = 1;
	for (i = 0; i < 5; i++)
		flg &= (read_reg(pf, i + 1) == expect[i]);

	if (verbose) {
		printk("%s: Reset (%d) signature = ", pf->name, k);
		for (i = 0; i < 5; i++)
			printk("%3x", read_reg(pf, i + 1));
		if (!flg)
			printk(" (incorrect)");
		printk("\n");
	}

	pi_disconnect(pf->pi);
	return flg - 1;
}

static void pf_mode_sense(struct pf_unit *pf)
{
	char ms_cmd[12] =
	    { ATAPI_MODE_SENSE, pf->lun << 5, 0, 0, 0, 0, 0, 0, 8, 0, 0, 0 };
	char buf[8];

	pf_atapi(pf, ms_cmd, 8, buf, "mode sense");
	pf->media_status = PF_RW;
	if (buf[3] & 0x80)
		pf->media_status = PF_RO;
}

static void xs(char *buf, char *targ, int offs, int len)
{
	int j, k, l;

	j = 0;
	l = 0;
	for (k = 0; k < len; k++)
		if ((buf[k + offs] != 0x20) || (buf[k + offs] != l))
			l = targ[j++] = buf[k + offs];
	if (l == 0x20)
		j--;
	targ[j] = 0;
}

static int xl(char *buf, int offs)
{
	int v, k;

	v = 0;
	for (k = 0; k < 4; k++)
		v = v * 256 + (buf[k + offs] & 0xff);
	return v;
}

static void pf_get_capacity(struct pf_unit *pf)
{
	char rc_cmd[12] = { ATAPI_CAPACITY, pf->lun << 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
	char buf[8];
	int bs;

	if (pf_atapi(pf, rc_cmd, 8, buf, "get capacity")) {
		pf->media_status = PF_NM;
		return;
	}
	set_capacity(pf->disk, xl(buf, 0) + 1);
	bs = xl(buf, 4);
	if (bs != 512) {
		set_capacity(pf->disk, 0);
		if (verbose)
			printk("%s: Drive %d, LUN %d,"
			       " unsupported block size %d\n",
			       pf->name, pf->drive, pf->lun, bs);
	}
}

static int pf_identify(struct pf_unit *pf)
{
	int dt, s;
	char *ms[2] = { "master", "slave" };
	char mf[10], id[18];
	char id_cmd[12] =
	    { ATAPI_IDENTIFY, pf->lun << 5, 0, 0, 36, 0, 0, 0, 0, 0, 0, 0 };
	char buf[36];

	s = pf_atapi(pf, id_cmd, 36, buf, "identify");
	if (s)
		return -1;

	dt = buf[0] & 0x1f;
	if ((dt != 0) && (dt != 7)) {
		if (verbose)
			printk("%s: Drive %d, LUN %d, unsupported type %d\n",
			       pf->name, pf->drive, pf->lun, dt);
		return -1;
	}

	xs(buf, mf, 8, 8);
	xs(buf, id, 16, 16);

	pf->removable = (buf[1] & 0x80);

	pf_mode_sense(pf);
	pf_mode_sense(pf);
	pf_mode_sense(pf);

	pf_get_capacity(pf);

	printk("%s: %s %s, %s LUN %d, type %d",
	       pf->name, mf, id, ms[pf->drive], pf->lun, dt);
	if (pf->removable)
		printk(", removable");
	if (pf->media_status == PF_NM)
		printk(", no media\n");
	else {
		if (pf->media_status == PF_RO)
			printk(", RO");
		printk(", %llu blocks\n",
			(unsigned long long)get_capacity(pf->disk));
	}
	return 0;
}

/*	returns  0, with id set if drive is detected
	        -1, if drive detection failed
*/
static int pf_probe(struct pf_unit *pf)
{
	if (pf->drive == -1) {
		for (pf->drive = 0; pf->drive <= 1; pf->drive++)
			if (!pf_reset(pf)) {
				if (pf->lun != -1)
					return pf_identify(pf);
				else
					for (pf->lun = 0; pf->lun < 8; pf->lun++)
						if (!pf_identify(pf))
							return 0;
			}
	} else {
		if (pf_reset(pf))
			return -1;
		if (pf->lun != -1)
			return pf_identify(pf);
		for (pf->lun = 0; pf->lun < 8; pf->lun++)
			if (!pf_identify(pf))
				return 0;
	}
	return -1;
}

static int pf_detect(void)
{
	struct pf_unit *pf = units;
	int k, unit;

	printk("%s: %s version %s, major %d, cluster %d, nice %d\n",
	       name, name, PF_VERSION, major, cluster, nice);

	k = 0;
	if (pf_drive_count == 0) {
		if (pi_init(pf->pi, 1, -1, -1, -1, -1, -1, pf_scratch, PI_PF,
			    verbose, pf->name)) {
			if (!pf_probe(pf) && pf->disk) {
				pf->present = 1;
				k++;
			} else
				pi_release(pf->pi);
		}

	} else
		for (unit = 0; unit < PF_UNITS; unit++, pf++) {
			int *conf = *drives[unit];
			if (!conf[D_PRT])
				continue;
			if (pi_init(pf->pi, 0, conf[D_PRT], conf[D_MOD],
				    conf[D_UNI], conf[D_PRO], conf[D_DLY],
				    pf_scratch, PI_PF, verbose, pf->name)) {
				if (pf->disk && !pf_probe(pf)) {
					pf->present = 1;
					k++;
				} else
					pi_release(pf->pi);
			}
		}
	if (k)
		return 0;

	printk("%s: No ATAPI disk detected\n", name);
	for (pf = units, unit = 0; unit < PF_UNITS; pf++, unit++)
		put_disk(pf->disk);
	return -1;
}

/* The i/o request engine */

static int pf_start(struct pf_unit *pf, int cmd, int b, int c)
{
	int i;
	char io_cmd[12] = { cmd, pf->lun << 5, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

	for (i = 0; i < 4; i++) {
		io_cmd[5 - i] = b & 0xff;
		b = b >> 8;
	}

	io_cmd[8] = c & 0xff;
	io_cmd[7] = (c >> 8) & 0xff;

	i = pf_command(pf, io_cmd, c * 512, "start i/o");

	mdelay(1);

	return i;
}

static int pf_ready(void)
{
	return (((status_reg(pf_current) & (STAT_BUSY | pf_mask)) == pf_mask));
}

static struct request_queue *pf_queue;

static void pf_end_request(int uptodate)
{
	if (pf_req) {
		end_request(pf_req, uptodate);
		pf_req = NULL;
	}
}

static void do_pf_request(struct request_queue * q)
{
	if (pf_busy)
		return;
repeat:
	pf_req = elv_next_request(q);
	if (!pf_req)
		return;

	pf_current = pf_req->rq_disk->private_data;
	pf_block = pf_req->sector;
	pf_run = pf_req->nr_sectors;
	pf_count = pf_req->current_nr_sectors;

	if (pf_block + pf_count > get_capacity(pf_req->rq_disk)) {
		pf_end_request(0);
		goto repeat;
	}

	pf_cmd = rq_data_dir(pf_req);
	pf_buf = pf_req->buffer;
	pf_retries = 0;

	pf_busy = 1;
	if (pf_cmd == READ)
		pi_do_claimed(pf_current->pi, do_pf_read);
	else if (pf_cmd == WRITE)
		pi_do_claimed(pf_current->pi, do_pf_write);
	else {
		pf_busy = 0;
		pf_end_request(0);
		goto repeat;
	}
}

static int pf_next_buf(void)
{
	unsigned long saved_flags;

	pf_count--;
	pf_run--;
	pf_buf += 512;
	pf_block++;
	if (!pf_run)
		return 1;
	if (!pf_count) {
		spin_lock_irqsave(&pf_spin_lock, saved_flags);
		pf_end_request(1);
		pf_req = elv_next_request(pf_queue);
		spin_unlock_irqrestore(&pf_spin_lock, saved_flags);
		if (!pf_req)
			return 1;
		pf_count = pf_req->current_nr_sectors;
		pf_buf = pf_req->buffer;
	}
	return 0;
}

static inline void next_request(int success)
{
	unsigned long saved_flags;

	spin_lock_irqsave(&pf_spin_lock, saved_flags);
	pf_end_request(success);
	pf_busy = 0;
	do_pf_request(pf_queue);
	spin_unlock_irqrestore(&pf_spin_lock, saved_flags);
}

/* detach from the calling context - in case the spinlock is held */
static void do_pf_read(void)
{
	ps_set_intr(do_pf_read_start, NULL, 0, nice);
}

static void do_pf_read_start(void)
{
	pf_busy = 1;

	if (pf_start(pf_current, ATAPI_READ_10, pf_block, pf_run)) {
		pi_disconnect(pf_current->pi);
		if (pf_retries < PF_MAX_RETRIES) {
			pf_retries++;
			pi_do_claimed(pf_current->pi, do_pf_read_start);
			return;
		}
		next_request(0);
		return;
	}
	pf_mask = STAT_DRQ;
	ps_set_intr(do_pf_read_drq, pf_ready, PF_TMO, nice);
}

static void do_pf_read_drq(void)
{
	while (1) {
		if (pf_wait(pf_current, STAT_BUSY, STAT_DRQ | STAT_ERR,
			    "read block", "completion") & STAT_ERR) {
			pi_disconnect(pf_current->pi);
			if (pf_retries < PF_MAX_RETRIES) {
				pf_req_sense(pf_current, 0);
				pf_retries++;
				pi_do_claimed(pf_current->pi, do_pf_read_start);
				return;
			}
			next_request(0);
			return;
		}
		pi_read_block(pf_current->pi, pf_buf, 512);
		if (pf_next_buf())
			break;
	}
	pi_disconnect(pf_current->pi);
	next_request(1);
}

static void do_pf_write(void)
{
	ps_set_intr(do_pf_write_start, NULL, 0, nice);
}

static void do_pf_write_start(void)
{
	pf_busy = 1;

	if (pf_start(pf_current, ATAPI_WRITE_10, pf_block, pf_run)) {
		pi_disconnect(pf_current->pi);
		if (pf_retries < PF_MAX_RETRIES) {
			pf_retries++;
			pi_do_claimed(pf_current->pi, do_pf_write_start);
			return;
		}
		next_request(0);
		return;
	}

	while (1) {
		if (pf_wait(pf_current, STAT_BUSY, STAT_DRQ | STAT_ERR,
			    "write block", "data wait") & STAT_ERR) {
			pi_disconnect(pf_current->pi);
			if (pf_retries < PF_MAX_RETRIES) {
				pf_retries++;
				pi_do_claimed(pf_current->pi, do_pf_write_start);
				return;
			}
			next_request(0);
			return;
		}
		pi_write_block(pf_current->pi, pf_buf, 512);
		if (pf_next_buf())
			break;
	}
	pf_mask = 0;
	ps_set_intr(do_pf_write_done, pf_ready, PF_TMO, nice);
}

static void do_pf_write_done(void)
{
	if (pf_wait(pf_current, STAT_BUSY, 0, "write block", "done") & STAT_ERR) {
		pi_disconnect(pf_current->pi);
		if (pf_retries < PF_MAX_RETRIES) {
			pf_retries++;
			pi_do_claimed(pf_current->pi, do_pf_write_start);
			return;
		}
		next_request(0);
		return;
	}
	pi_disconnect(pf_current->pi);
	next_request(1);
}

static int __init pf_init(void)
{				/* preliminary initialisation */
	struct pf_unit *pf;
	int unit;

	if (disable)
		return -EINVAL;

	pf_init_units();

	if (pf_detect())
		return -ENODEV;
	pf_busy = 0;

	if (register_blkdev(major, name)) {
		for (pf = units, unit = 0; unit < PF_UNITS; pf++, unit++)
			put_disk(pf->disk);
		return -EBUSY;
	}
	pf_queue = blk_init_queue(do_pf_request, &pf_spin_lock);
	if (!pf_queue) {
		unregister_blkdev(major, name);
		for (pf = units, unit = 0; unit < PF_UNITS; pf++, unit++)
			put_disk(pf->disk);
		return -ENOMEM;
	}

	blk_queue_max_phys_segments(pf_queue, cluster);
	blk_queue_max_hw_segments(pf_queue, cluster);

	for (pf = units, unit = 0; unit < PF_UNITS; pf++, unit++) {
		struct gendisk *disk = pf->disk;

		if (!pf->present)
			continue;
		disk->private_data = pf;
		disk->queue = pf_queue;
		add_disk(disk);
	}
	return 0;
}

static void __exit pf_exit(void)
{
	struct pf_unit *pf;
	int unit;
	unregister_blkdev(major, name);
	for (pf = units, unit = 0; unit < PF_UNITS; pf++, unit++) {
		if (!pf->present)
			continue;
		del_gendisk(pf->disk);
		put_disk(pf->disk);
		pi_release(pf->pi);
	}
	blk_cleanup_queue(pf_queue);
}

MODULE_LICENSE("GPL");
module_init(pf_init)
module_exit(pf_exit)