summaryrefslogtreecommitdiffstats
path: root/drivers/media/video/cpia_pp.c
blob: c431df8248d659199c66da758e6afcd35a918575 (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
/*
 * cpia_pp CPiA Parallel Port driver
 *
 * Supports CPiA based parallel port Video Camera's.
 *
 * (C) Copyright 1999 Bas Huisman <bhuism@cs.utwente.nl>
 * (C) Copyright 1999-2000 Scott J. Bertin <sbertin@securenym.net>,
 * (C) Copyright 1999-2000 Peter Pregler <Peter_Pregler@email.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/* define _CPIA_DEBUG_ for verbose debug output (see cpia.h) */
/* #define _CPIA_DEBUG_  1 */


#include <linux/module.h>
#include <linux/init.h>

#include <linux/kernel.h>
#include <linux/parport.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/workqueue.h>
#include <linux/sched.h>

#include <linux/kmod.h>

/* #define _CPIA_DEBUG_		define for verbose debug output */
#include "cpia.h"

static int cpia_pp_open(void *privdata);
static int cpia_pp_registerCallback(void *privdata, void (*cb) (void *cbdata),
				    void *cbdata);
static int cpia_pp_transferCmd(void *privdata, u8 *command, u8 *data);
static int cpia_pp_streamStart(void *privdata);
static int cpia_pp_streamStop(void *privdata);
static int cpia_pp_streamRead(void *privdata, u8 *buffer, int noblock);
static int cpia_pp_close(void *privdata);


#define ABOUT "Parallel port driver for Vision CPiA based cameras"

#define PACKET_LENGTH  8

/* Magic numbers for defining port-device mappings */
#define PPCPIA_PARPORT_UNSPEC -4
#define PPCPIA_PARPORT_AUTO -3
#define PPCPIA_PARPORT_OFF -2
#define PPCPIA_PARPORT_NONE -1

static int parport_nr[PARPORT_MAX] = {[0 ... PARPORT_MAX - 1] = PPCPIA_PARPORT_UNSPEC};
static char *parport[PARPORT_MAX] = {NULL,};

MODULE_AUTHOR("B. Huisman <bhuism@cs.utwente.nl> & Peter Pregler <Peter_Pregler@email.com>");
MODULE_DESCRIPTION("Parallel port driver for Vision CPiA based cameras");
MODULE_LICENSE("GPL");

module_param_array(parport, charp, NULL, 0);
MODULE_PARM_DESC(parport, "'auto' or a list of parallel port numbers. Just like lp.");

struct pp_cam_entry {
	struct pardevice *pdev;
	struct parport *port;
	struct work_struct cb_task;
	void (*cb_func)(void *cbdata);
	void *cb_data;
	int open_count;
	wait_queue_head_t wq_stream;
	/* image state flags */
	int image_ready;	/* we got an interrupt */
	int image_complete;	/* we have seen 4 EOI */

	int streaming; /* we are in streaming mode */
	int stream_irq;
};

static struct cpia_camera_ops cpia_pp_ops =
{
	cpia_pp_open,
	cpia_pp_registerCallback,
	cpia_pp_transferCmd,
	cpia_pp_streamStart,
	cpia_pp_streamStop,
	cpia_pp_streamRead,
	cpia_pp_close,
	1,
	THIS_MODULE
};

static LIST_HEAD(cam_list);
static spinlock_t cam_list_lock_pp;

/* FIXME */
static void cpia_parport_enable_irq( struct parport *port ) {
	parport_enable_irq(port);
	mdelay(10);
	return;
}

static void cpia_parport_disable_irq( struct parport *port ) {
	parport_disable_irq(port);
	mdelay(10);
	return;
}

/* Special CPiA PPC modes: These are invoked by using the 1284 Extensibility
 * Link Flag during negotiation */
#define UPLOAD_FLAG  0x08
#define NIBBLE_TRANSFER 0x01
#define ECP_TRANSFER 0x03

#define PARPORT_CHUNK_SIZE	PAGE_SIZE


static void cpia_pp_run_callback(struct work_struct *work)
{
	void (*cb_func)(void *cbdata);
	void *cb_data;
	struct pp_cam_entry *cam;

	cam = container_of(work, struct pp_cam_entry, cb_task);
	cb_func = cam->cb_func;
	cb_data = cam->cb_data;

	cb_func(cb_data);
}

/****************************************************************************
 *
 *  CPiA-specific  low-level parport functions for nibble uploads
 *
 ***************************************************************************/
/*  CPiA nonstandard "Nibble" mode (no nDataAvail signal after each byte). */
/* The standard kernel parport_ieee1284_read_nibble() fails with the CPiA... */

static size_t cpia_read_nibble (struct parport *port,
			 void *buffer, size_t len,
			 int flags)
{
	/* adapted verbatim, with one change, from
	   parport_ieee1284_read_nibble() in drivers/parport/ieee1284-ops.c */

	unsigned char *buf = buffer;
	int i;
	unsigned char byte = 0;

	len *= 2; /* in nibbles */
	for (i=0; i < len; i++) {
		unsigned char nibble;

		/* The CPiA firmware suppresses the use of nDataAvail (nFault LO)
		 * after every second nibble to signal that more
		 * data is available.  (the total number of Bytes that
		 * should be sent is known; if too few are received, an error
		 * will be recorded after a timeout).
		 * This is incompatible with parport_ieee1284_read_nibble(),
		 * which expects to find nFault LO after every second nibble.
		 */

		/* Solution: modify cpia_read_nibble to only check for
		 * nDataAvail before the first nibble is sent.
		 */

		/* Does the error line indicate end of data? */
		if (((i /*& 1*/) == 0) &&
		    (parport_read_status(port) & PARPORT_STATUS_ERROR)) {
			DBG("%s: No more nibble data (%d bytes)\n",
			    port->name, i/2);
			goto end_of_data;
		}

		/* Event 7: Set nAutoFd low. */
		parport_frob_control (port,
				      PARPORT_CONTROL_AUTOFD,
				      PARPORT_CONTROL_AUTOFD);

		/* Event 9: nAck goes low. */
		port->ieee1284.phase = IEEE1284_PH_REV_DATA;
		if (parport_wait_peripheral (port,
					     PARPORT_STATUS_ACK, 0)) {
			/* Timeout -- no more data? */
				 DBG("%s: Nibble timeout at event 9 (%d bytes)\n",
				 port->name, i/2);
			parport_frob_control (port, PARPORT_CONTROL_AUTOFD, 0);
			break;
		}


		/* Read a nibble. */
		nibble = parport_read_status (port) >> 3;
		nibble &= ~8;
		if ((nibble & 0x10) == 0)
			nibble |= 8;
		nibble &= 0xf;

		/* Event 10: Set nAutoFd high. */
		parport_frob_control (port, PARPORT_CONTROL_AUTOFD, 0);

		/* Event 11: nAck goes high. */
		if (parport_wait_peripheral (port,
					     PARPORT_STATUS_ACK,
					     PARPORT_STATUS_ACK)) {
			/* Timeout -- no more data? */
			DBG("%s: Nibble timeout at event 11\n",
				 port->name);
			break;
		}

		if (i & 1) {
			/* Second nibble */
			byte |= nibble << 4;
			*buf++ = byte;
		} else
			byte = nibble;
	}

	if (i == len) {
		/* Read the last nibble without checking data avail. */
		if (parport_read_status (port) & PARPORT_STATUS_ERROR) {
		end_of_data:
			/* Go to reverse idle phase. */
			parport_frob_control (port,
					      PARPORT_CONTROL_AUTOFD,
					      PARPORT_CONTROL_AUTOFD);
			port->physport->ieee1284.phase = IEEE1284_PH_REV_IDLE;
		}
		else
			port->physport->ieee1284.phase = IEEE1284_PH_HBUSY_DAVAIL;
	}

	return i/2;
}

/* CPiA nonstandard "Nibble Stream" mode (2 nibbles per cycle, instead of 1)
 * (See CPiA Data sheet p. 31)
 *
 * "Nibble Stream" mode used by CPiA for uploads to non-ECP ports is a
 * nonstandard variant of nibble mode which allows the same (mediocre)
 * data flow of 8 bits per cycle as software-enabled ECP by TRISTATE-capable
 * parallel ports, but works also for  non-TRISTATE-capable ports.
 * (Standard nibble mode only send 4 bits per cycle)
 *
 */

static size_t cpia_read_nibble_stream(struct parport *port,
			       void *buffer, size_t len,
			       int flags)
{
	int i;
	unsigned char *buf = buffer;
	int endseen = 0;

	for (i=0; i < len; i++) {
		unsigned char nibble[2], byte = 0;
		int j;

		/* Image Data is complete when 4 consecutive EOI bytes (0xff) are seen */
		if (endseen > 3 )
			break;

		/* Event 7: Set nAutoFd low. */
		parport_frob_control (port,
				      PARPORT_CONTROL_AUTOFD,
				      PARPORT_CONTROL_AUTOFD);

		/* Event 9: nAck goes low. */
		port->ieee1284.phase = IEEE1284_PH_REV_DATA;
		if (parport_wait_peripheral (port,
					     PARPORT_STATUS_ACK, 0)) {
			/* Timeout -- no more data? */
				 DBG("%s: Nibble timeout at event 9 (%d bytes)\n",
				 port->name, i/2);
			parport_frob_control (port, PARPORT_CONTROL_AUTOFD, 0);
			break;
		}

		/* Read lower nibble */
		nibble[0] = parport_read_status (port) >>3;

		/* Event 10: Set nAutoFd high. */
		parport_frob_control (port, PARPORT_CONTROL_AUTOFD, 0);

		/* Event 11: nAck goes high. */
		if (parport_wait_peripheral (port,
					     PARPORT_STATUS_ACK,
					     PARPORT_STATUS_ACK)) {
			/* Timeout -- no more data? */
			DBG("%s: Nibble timeout at event 11\n",
				 port->name);
			break;
		}

		/* Read upper nibble */
		nibble[1] = parport_read_status (port) >>3;

		/* reassemble the byte */
		for (j = 0; j < 2 ; j++ ) {
			nibble[j] &= ~8;
			if ((nibble[j] & 0x10) == 0)
				nibble[j] |= 8;
			nibble[j] &= 0xf;
		}
		byte = (nibble[0] |(nibble[1] << 4));
		*buf++ = byte;

		if(byte == EOI)
		  endseen++;
		else
		  endseen = 0;
	}
	return i;
}

/****************************************************************************
 *
 *  EndTransferMode
 *
 ***************************************************************************/
static void EndTransferMode(struct pp_cam_entry *cam)
{
	parport_negotiate(cam->port, IEEE1284_MODE_COMPAT);
}

/****************************************************************************
 *
 *  ForwardSetup
 *
 ***************************************************************************/
static int ForwardSetup(struct pp_cam_entry *cam)
{
	int retry;

	/* The CPiA uses ECP protocol for Downloads from the Host to the camera.
	 * This will be software-emulated if ECP hardware is not present
	 */

	/* the usual camera maximum response time is 10ms, but after receiving
	 * some commands, it needs up to 40ms. (Data Sheet p. 32)*/

	for(retry = 0; retry < 4; ++retry) {
		if(!parport_negotiate(cam->port, IEEE1284_MODE_ECP)) {
			break;
		}
		mdelay(10);
	}
	if(retry == 4) {
		DBG("Unable to negotiate IEEE1284 ECP Download mode\n");
		return -1;
	}
	return 0;
}
/****************************************************************************
 *
 *  ReverseSetup
 *
 ***************************************************************************/
static int ReverseSetup(struct pp_cam_entry *cam, int extensibility)
{
	int retry;
	int upload_mode, mode = IEEE1284_MODE_ECP;
	int transfer_mode = ECP_TRANSFER;

	if (!(cam->port->modes & PARPORT_MODE_ECP) &&
	     !(cam->port->modes & PARPORT_MODE_TRISTATE)) {
		mode = IEEE1284_MODE_NIBBLE;
		transfer_mode = NIBBLE_TRANSFER;
	}

	upload_mode = mode;
	if(extensibility) mode = UPLOAD_FLAG|transfer_mode|IEEE1284_EXT_LINK;

	/* the usual camera maximum response time is 10ms, but after
	 * receiving some commands, it needs up to 40ms. */

	for(retry = 0; retry < 4; ++retry) {
		if(!parport_negotiate(cam->port, mode)) {
			break;
		}
		mdelay(10);
	}
	if(retry == 4) {
		if(extensibility)
			DBG("Unable to negotiate upload extensibility mode\n");
		else
			DBG("Unable to negotiate upload mode\n");
		return -1;
	}
	if(extensibility) cam->port->ieee1284.mode = upload_mode;
	return 0;
}

/****************************************************************************
 *
 *  WritePacket
 *
 ***************************************************************************/
static int WritePacket(struct pp_cam_entry *cam, const u8 *packet, size_t size)
{
	int retval=0;
	int size_written;

	if (packet == NULL) {
		return -EINVAL;
	}
	if (ForwardSetup(cam)) {
		DBG("Write failed in setup\n");
		return -EIO;
	}
	size_written = parport_write(cam->port, packet, size);
	if(size_written != size) {
		DBG("Write failed, wrote %d/%d\n", size_written, size);
		retval = -EIO;
	}
	EndTransferMode(cam);
	return retval;
}

/****************************************************************************
 *
 *  ReadPacket
 *
 ***************************************************************************/
static int ReadPacket(struct pp_cam_entry *cam, u8 *packet, size_t size)
{
	int retval=0;

	if (packet == NULL) {
		return -EINVAL;
	}
	if (ReverseSetup(cam, 0)) {
		return -EIO;
	}

	/* support for CPiA variant nibble reads */
	if(cam->port->ieee1284.mode == IEEE1284_MODE_NIBBLE) {
		if(cpia_read_nibble(cam->port, packet, size, 0) != size)
			retval = -EIO;
	} else {
		if(parport_read(cam->port, packet, size) != size)
			retval = -EIO;
	}
	EndTransferMode(cam);
	return retval;
}

/****************************************************************************
 *
 *  cpia_pp_streamStart
 *
 ***************************************************************************/
static int cpia_pp_streamStart(void *privdata)
{
	struct pp_cam_entry *cam = privdata;
	DBG("\n");
	cam->streaming=1;
	cam->image_ready=0;
	//if (ReverseSetup(cam,1)) return -EIO;
	if(cam->stream_irq) cpia_parport_enable_irq(cam->port);
	return 0;
}

/****************************************************************************
 *
 *  cpia_pp_streamStop
 *
 ***************************************************************************/
static int cpia_pp_streamStop(void *privdata)
{
	struct pp_cam_entry *cam = privdata;

	DBG("\n");
	cam->streaming=0;
	cpia_parport_disable_irq(cam->port);
	//EndTransferMode(cam);

	return 0;
}

/****************************************************************************
 *
 *  cpia_pp_streamRead
 *
 ***************************************************************************/
static int cpia_pp_read(struct parport *port, u8 *buffer, int len)
{
	int bytes_read;

	/* support for CPiA variant "nibble stream" reads */
	if(port->ieee1284.mode == IEEE1284_MODE_NIBBLE)
		bytes_read = cpia_read_nibble_stream(port,buffer,len,0);
	else {
		int new_bytes;
		for(bytes_read=0; bytes_read<len; bytes_read += new_bytes) {
			new_bytes = parport_read(port, buffer+bytes_read,
						 len-bytes_read);
			if(new_bytes < 0) break;
		}
	}
	return bytes_read;
}

static int cpia_pp_streamRead(void *privdata, u8 *buffer, int noblock)
{
	struct pp_cam_entry *cam = privdata;
	int read_bytes = 0;
	int i, endseen, block_size, new_bytes;

	if(cam == NULL) {
		DBG("Internal driver error: cam is NULL\n");
		return -EINVAL;
	}
	if(buffer == NULL) {
		DBG("Internal driver error: buffer is NULL\n");
		return -EINVAL;
	}
	//if(cam->streaming) DBG("%d / %d\n", cam->image_ready, noblock);
	if( cam->stream_irq ) {
		DBG("%d\n", cam->image_ready);
		cam->image_ready--;
	}
	cam->image_complete=0;
	if (0/*cam->streaming*/) {
		if(!cam->image_ready) {
			if(noblock) return -EWOULDBLOCK;
			interruptible_sleep_on(&cam->wq_stream);
			if( signal_pending(current) ) return -EINTR;
			DBG("%d\n", cam->image_ready);
		}
	} else {
		if (ReverseSetup(cam, 1)) {
			DBG("unable to ReverseSetup\n");
			return -EIO;
		}
	}
	endseen = 0;
	block_size = PARPORT_CHUNK_SIZE;
	while( !cam->image_complete ) {
		cond_resched();

		new_bytes = cpia_pp_read(cam->port, buffer, block_size );
		if( new_bytes <= 0 ) {
			break;
		}
		i=-1;
		while(++i<new_bytes && endseen<4) {
			if(*buffer==EOI) {
				endseen++;
			} else {
				endseen=0;
			}
			buffer++;
		}
		read_bytes += i;
		if( endseen==4 ) {
			cam->image_complete=1;
			break;
		}
		if( CPIA_MAX_IMAGE_SIZE-read_bytes <= PARPORT_CHUNK_SIZE ) {
			block_size=CPIA_MAX_IMAGE_SIZE-read_bytes;
		}
	}
	EndTransferMode(cam);
	return cam->image_complete ? read_bytes : -EIO;
}
/****************************************************************************
 *
 *  cpia_pp_transferCmd
 *
 ***************************************************************************/
static int cpia_pp_transferCmd(void *privdata, u8 *command, u8 *data)
{
	int err;
	int retval=0;
	int databytes;
	struct pp_cam_entry *cam = privdata;

	if(cam == NULL) {
		DBG("Internal driver error: cam is NULL\n");
		return -EINVAL;
	}
	if(command == NULL) {
		DBG("Internal driver error: command is NULL\n");
		return -EINVAL;
	}
	databytes = (((int)command[7])<<8) | command[6];
	if ((err = WritePacket(cam, command, PACKET_LENGTH)) < 0) {
		DBG("Error writing command\n");
		return err;
	}
	if(command[0] == DATA_IN) {
		u8 buffer[8];
		if(data == NULL) {
			DBG("Internal driver error: data is NULL\n");
			return -EINVAL;
		}
		if((err = ReadPacket(cam, buffer, 8)) < 0) {
			DBG("Error reading command result\n");
		       return err;
		}
		memcpy(data, buffer, databytes);
	} else if(command[0] == DATA_OUT) {
		if(databytes > 0) {
			if(data == NULL) {
				DBG("Internal driver error: data is NULL\n");
				retval = -EINVAL;
			} else {
				if((err=WritePacket(cam, data, databytes)) < 0){
					DBG("Error writing command data\n");
					return err;
				}
			}
		}
	} else {
		DBG("Unexpected first byte of command: %x\n", command[0]);
		retval = -EINVAL;
	}
	return retval;
}

/****************************************************************************
 *
 *  cpia_pp_open
 *
 ***************************************************************************/
static int cpia_pp_open(void *privdata)
{
	struct pp_cam_entry *cam = (struct pp_cam_entry *)privdata;

	if (cam == NULL)
		return -EINVAL;

	if(cam->open_count == 0) {
		if (parport_claim(cam->pdev)) {
			DBG("failed to claim the port\n");
			return -EBUSY;
		}
		parport_negotiate(cam->port, IEEE1284_MODE_COMPAT);
		parport_data_forward(cam->port);
		parport_write_control(cam->port, PARPORT_CONTROL_SELECT);
		udelay(50);
		parport_write_control(cam->port,
				      PARPORT_CONTROL_SELECT
				      | PARPORT_CONTROL_INIT);
	}

	++cam->open_count;

	return 0;
}

/****************************************************************************
 *
 *  cpia_pp_registerCallback
 *
 ***************************************************************************/
static int cpia_pp_registerCallback(void *privdata, void (*cb)(void *cbdata), void *cbdata)
{
	struct pp_cam_entry *cam = privdata;
	int retval = 0;

	if(cam->port->irq != PARPORT_IRQ_NONE) {
		cam->cb_func = cb;
		cam->cb_data = cbdata;
		INIT_WORK(&cam->cb_task, cpia_pp_run_callback);
	} else {
		retval = -1;
	}
	return retval;
}

/****************************************************************************
 *
 *  cpia_pp_close
 *
 ***************************************************************************/
static int cpia_pp_close(void *privdata)
{
	struct pp_cam_entry *cam = privdata;
	if (--cam->open_count == 0) {
		parport_release(cam->pdev);
	}
	return 0;
}

/****************************************************************************
 *
 *  cpia_pp_register
 *
 ***************************************************************************/
static int cpia_pp_register(struct parport *port)
{
	struct pardevice *pdev = NULL;
	struct pp_cam_entry *cam;
	struct cam_data *cpia;

	if (!(port->modes & PARPORT_MODE_PCSPP)) {
		LOG("port is not supported by CPiA driver\n");
		return -ENXIO;
	}

	cam = kzalloc(sizeof(struct pp_cam_entry), GFP_KERNEL);
	if (cam == NULL) {
		LOG("failed to allocate camera structure\n");
		return -ENOMEM;
	}

	pdev = parport_register_device(port, "cpia_pp", NULL, NULL,
				       NULL, 0, cam);

	if (!pdev) {
		LOG("failed to parport_register_device\n");
		kfree(cam);
		return -ENXIO;
	}

	cam->pdev = pdev;
	cam->port = port;
	init_waitqueue_head(&cam->wq_stream);

	cam->streaming = 0;
	cam->stream_irq = 0;

	if((cpia = cpia_register_camera(&cpia_pp_ops, cam)) == NULL) {
		LOG("failed to cpia_register_camera\n");
		parport_unregister_device(pdev);
		kfree(cam);
		return -ENXIO;
	}
	spin_lock( &cam_list_lock_pp );
	list_add( &cpia->cam_data_list, &cam_list );
	spin_unlock( &cam_list_lock_pp );

	return 0;
}

static void cpia_pp_detach (struct parport *port)
{
	struct list_head *tmp;
	struct cam_data *cpia = NULL;
	struct pp_cam_entry *cam;

	spin_lock( &cam_list_lock_pp );
	list_for_each (tmp, &cam_list) {
		cpia = list_entry(tmp, struct cam_data, cam_data_list);
		cam = (struct pp_cam_entry *) cpia->lowlevel_data;
		if (cam && cam->port->number == port->number) {
			list_del(&cpia->cam_data_list);
			break;
		}
		cpia = NULL;
	}
	spin_unlock( &cam_list_lock_pp );

	if (!cpia) {
		DBG("cpia_pp_detach failed to find cam_data in cam_list\n");
		return;
	}

	cam = (struct pp_cam_entry *) cpia->lowlevel_data;
	cpia_unregister_camera(cpia);
	if(cam->open_count > 0)
		cpia_pp_close(cam);
	parport_unregister_device(cam->pdev);
	cpia->lowlevel_data = NULL;
	kfree(cam);
}

static void cpia_pp_attach (struct parport *port)
{
	unsigned int i;

	switch (parport_nr[0])
	{
	case PPCPIA_PARPORT_UNSPEC:
	case PPCPIA_PARPORT_AUTO:
		if (port->probe_info[0].class != PARPORT_CLASS_MEDIA ||
		    port->probe_info[0].cmdset == NULL ||
		    strncmp(port->probe_info[0].cmdset, "CPIA_1", 6) != 0)
			return;

		cpia_pp_register(port);

		break;

	default:
		for (i = 0; i < PARPORT_MAX; ++i) {
			if (port->number == parport_nr[i]) {
				cpia_pp_register(port);
				break;
			}
		}
		break;
	}
}

static struct parport_driver cpia_pp_driver = {
	.name = "cpia_pp",
	.attach = cpia_pp_attach,
	.detach = cpia_pp_detach,
};

static int __init cpia_pp_init(void)
{
	printk(KERN_INFO "%s v%d.%d.%d\n",ABOUT,
	       CPIA_PP_MAJ_VER,CPIA_PP_MIN_VER,CPIA_PP_PATCH_VER);

	if(parport_nr[0] == PPCPIA_PARPORT_OFF) {
		printk("  disabled\n");
		return 0;
	}

	spin_lock_init( &cam_list_lock_pp );

	if (parport_register_driver (&cpia_pp_driver)) {
		LOG ("unable to register with parport\n");
		return -EIO;
	}
	return 0;
}

static int __init cpia_init(void)
{
	if (parport[0]) {
		/* The user gave some parameters.  Let's see what they were. */
		if (!strncmp(parport[0], "auto", 4)) {
			parport_nr[0] = PPCPIA_PARPORT_AUTO;
		} else {
			int n;
			for (n = 0; n < PARPORT_MAX && parport[n]; n++) {
				if (!strncmp(parport[n], "none", 4)) {
					parport_nr[n] = PPCPIA_PARPORT_NONE;
				} else {
					char *ep;
					unsigned long r = simple_strtoul(parport[n], &ep, 0);
					if (ep != parport[n]) {
						parport_nr[n] = r;
					} else {
						LOG("bad port specifier `%s'\n", parport[n]);
						return -ENODEV;
					}
				}
			}
		}
	}
	return cpia_pp_init();
}

static void __exit cpia_cleanup(void)
{
	parport_unregister_driver(&cpia_pp_driver);
	return;
}

module_init(cpia_init);
module_exit(cpia_cleanup);