summaryrefslogtreecommitdiffstats
path: root/drivers/usb/image/mdc800.c
blob: 7121b50098d3fce810bbed9277a9dd4019e4b641 (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
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
/*
 * copyright (C) 1999/2000 by Henning Zabel <henning@uni-paderborn.de>
 *
 * 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.
 */


/*
 *	USB-Kernel Driver for the Mustek MDC800 Digital Camera
 *	(c) 1999/2000 Henning Zabel <henning@uni-paderborn.de>
 *
 *
 * The driver brings the USB functions of the MDC800 to Linux.
 * To use the Camera you must support the USB Protocol of the camera
 * to the Kernel Node.
 * The Driver uses a misc device Node. Create it with :
 * mknod /dev/mustek c 180 32
 *
 * The driver supports only one camera.
 * 
 * Fix: mdc800 used sleep_on and slept with io_lock held.
 * Converted sleep_on to waitqueues with schedule_timeout and made io_lock
 * a semaphore from a spinlock.
 * by Oliver Neukum <oliver@neukum.name>
 * (02/12/2001)
 * 
 * Identify version on module load.
 * (08/04/2001) gb
 *
 * version 0.7.5
 * Fixed potential SMP races with Spinlocks.
 * Thanks to Oliver Neukum <oliver@neukum.name> who 
 * noticed the race conditions.
 * (30/10/2000)
 *
 * Fixed: Setting urb->dev before submitting urb.
 * by Greg KH <greg@kroah.com>
 * (13/10/2000)
 *
 * version 0.7.3
 * bugfix : The mdc800->state field gets set to READY after the
 * the diconnect function sets it to NOT_CONNECTED. This makes the
 * driver running like the camera is connected and causes some
 * hang ups.
 *
 * version 0.7.1
 * MOD_INC and MOD_DEC are changed in usb_probe to prevent load/unload
 * problems when compiled as Module.
 * (04/04/2000)
 *
 * The mdc800 driver gets assigned the USB Minor 32-47. The Registration
 * was updated to use these values.
 * (26/03/2000)
 *
 * The Init und Exit Module Function are updated.
 * (01/03/2000)
 *
 * version 0.7.0
 * Rewrite of the driver : The driver now uses URB's. The old stuff
 * has been removed.
 *
 * version 0.6.0
 * Rewrite of this driver: The Emulation of the rs232 protocoll
 * has been removed from the driver. A special executeCommand function
 * for this driver is included to gphoto.
 * The driver supports two kind of communication to bulk endpoints.
 * Either with the dev->bus->ops->bulk... or with callback function.
 * (09/11/1999)
 *
 * version 0.5.0:
 * first Version that gets a version number. Most of the needed
 * functions work.
 * (20/10/1999)
 */

#include <linux/sched.h>
#include <linux/signal.h>
#include <linux/spinlock.h>
#include <linux/errno.h>
#include <linux/random.h>
#include <linux/poll.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/wait.h>
#include <linux/mutex.h>

#include <linux/usb.h>
#include <linux/fs.h>

/*
 * Version Information
 */
#define DRIVER_VERSION "v0.7.5 (30/10/2000)"
#define DRIVER_AUTHOR "Henning Zabel <henning@uni-paderborn.de>"
#define DRIVER_DESC "USB Driver for Mustek MDC800 Digital Camera"

/* Vendor and Product Information */
#define MDC800_VENDOR_ID 	0x055f
#define MDC800_PRODUCT_ID	0xa800

/* Timeouts (msec) */
#define TO_DOWNLOAD_GET_READY		1500
#define TO_DOWNLOAD_GET_BUSY		1500
#define TO_WRITE_GET_READY		1000
#define TO_DEFAULT_COMMAND		5000
#define TO_READ_FROM_IRQ 		TO_DEFAULT_COMMAND
#define TO_GET_READY			TO_DEFAULT_COMMAND

/* Minor Number of the device (create with mknod /dev/mustek c 180 32) */
#define MDC800_DEVICE_MINOR_BASE 32


/**************************************************************************
	Data and structs
***************************************************************************/


typedef enum {
	NOT_CONNECTED, READY, WORKING, DOWNLOAD
} mdc800_state;


/* Data for the driver */
struct mdc800_data
{
	struct usb_device *	dev;			// Device Data
	mdc800_state 		state;

	unsigned int		endpoint [4];

	struct urb *		irq_urb;
	wait_queue_head_t	irq_wait;
	int			irq_woken;
	char*			irq_urb_buffer;

	int			camera_busy;          // is camera busy ?
	int 			camera_request_ready; // Status to synchronize with irq
	char 			camera_response [8];  // last Bytes send after busy

	struct urb *   		write_urb;
	char*			write_urb_buffer;
	wait_queue_head_t	write_wait;
	int			written;


	struct urb *   		download_urb;
	char*			download_urb_buffer;
	wait_queue_head_t	download_wait;
	int			downloaded;
	int			download_left;		// Bytes left to download ?


	/* Device Data */
	char			out [64];	// Answer Buffer
	int 			out_ptr;	// Index to the first not readen byte
	int			out_count;	// Bytes in the buffer

	int			open;		// Camera device open ?
	struct mutex		io_lock;	// IO -lock

	char 			in [8];		// Command Input Buffer
	int  			in_count;

	int			pic_index;	// Cache for the Imagesize (-1 for nothing cached )
	int			pic_len;
	int			minor;
};


/* Specification of the Endpoints */
static struct usb_endpoint_descriptor mdc800_ed [4] =
{
	{ 
		.bLength = 		0,
		.bDescriptorType =	0,
		.bEndpointAddress =	0x01,
		.bmAttributes = 	0x02,
		.wMaxPacketSize =	cpu_to_le16(8),
		.bInterval = 		0,
		.bRefresh = 		0,
		.bSynchAddress = 	0,
	},
	{
		.bLength = 		0,
		.bDescriptorType = 	0,
		.bEndpointAddress = 	0x82,
		.bmAttributes = 	0x03,
		.wMaxPacketSize = 	cpu_to_le16(8),
		.bInterval = 		0,
		.bRefresh = 		0,
		.bSynchAddress = 	0,
	},
	{
		.bLength = 		0,
		.bDescriptorType = 	0,
		.bEndpointAddress = 	0x03,
		.bmAttributes = 	0x02,
		.wMaxPacketSize = 	cpu_to_le16(64),
		.bInterval = 		0,
		.bRefresh = 		0,
		.bSynchAddress = 	0,
	},
	{
		.bLength = 		0,
		.bDescriptorType = 	0,
		.bEndpointAddress = 	0x84,
		.bmAttributes = 	0x02,
		.wMaxPacketSize = 	cpu_to_le16(64),
		.bInterval = 		0,
		.bRefresh = 		0,
		.bSynchAddress = 	0,
	},
};

/* The Variable used by the driver */
static struct mdc800_data* mdc800;


/***************************************************************************
	The USB Part of the driver
****************************************************************************/

static int mdc800_endpoint_equals (struct usb_endpoint_descriptor *a,struct usb_endpoint_descriptor *b)
{
	return (
		   ( a->bEndpointAddress == b->bEndpointAddress )
		&& ( a->bmAttributes     == b->bmAttributes     )
		&& ( a->wMaxPacketSize   == b->wMaxPacketSize   )
	);
}


/*
 * Checks whether the camera responds busy
 */
static int mdc800_isBusy (char* ch)
{
	int i=0;
	while (i<8)
	{
		if (ch [i] != (char)0x99)
			return 0;
		i++;
	}
	return 1;
}


/*
 * Checks whether the Camera is ready
 */
static int mdc800_isReady (char *ch)
{
	int i=0;
	while (i<8)
	{
		if (ch [i] != (char)0xbb)
			return 0;
		i++;
	}
	return 1;
}



/*
 * USB IRQ Handler for InputLine
 */
static void mdc800_usb_irq (struct urb *urb)
{
	int data_received=0, wake_up;
	unsigned char* b=urb->transfer_buffer;
	struct mdc800_data* mdc800=urb->context;
	struct device *dev = &mdc800->dev->dev;
	int status = urb->status;

	if (status >= 0) {
		if (mdc800_isBusy (b))
		{
			if (!mdc800->camera_busy)
			{
				mdc800->camera_busy=1;
				dev_dbg(dev, "gets busy\n");
			}
		}
		else
		{
			if (mdc800->camera_busy && mdc800_isReady (b))
			{
				mdc800->camera_busy=0;
				dev_dbg(dev, "gets ready\n");
			}
		}
		if (!(mdc800_isBusy (b) || mdc800_isReady (b)))
		{
			/* Store Data in camera_answer field */
			dev_dbg(dev, "%i %i %i %i %i %i %i %i \n",b[0],b[1],b[2],b[3],b[4],b[5],b[6],b[7]);

			memcpy (mdc800->camera_response,b,8);
			data_received=1;
		}
	}
	wake_up= ( mdc800->camera_request_ready > 0 )
		&&
		(
			((mdc800->camera_request_ready == 1) && (!mdc800->camera_busy))
		||
			((mdc800->camera_request_ready == 2) && data_received)
		||
			((mdc800->camera_request_ready == 3) && (mdc800->camera_busy))
		||
			(status < 0)
		);

	if (wake_up)
	{
		mdc800->camera_request_ready=0;
		mdc800->irq_woken=1;
		wake_up (&mdc800->irq_wait);
	}
}


/*
 * Waits a while until the irq responds that camera is ready
 *
 *  mode : 0: Wait for camera gets ready
 *         1: Wait for receiving data
 *         2: Wait for camera gets busy
 *
 * msec: Time to wait
 */
static int mdc800_usb_waitForIRQ (int mode, int msec)
{
	mdc800->camera_request_ready=1+mode;

	wait_event_timeout(mdc800->irq_wait, mdc800->irq_woken, msec*HZ/1000);
	mdc800->irq_woken = 0;

	if (mdc800->camera_request_ready>0)
	{
		mdc800->camera_request_ready=0;
		dev_err(&mdc800->dev->dev, "timeout waiting for camera.\n");
		return -1;
	}
	
	if (mdc800->state == NOT_CONNECTED)
	{
		printk(KERN_WARNING "mdc800: Camera gets disconnected "
		       "during waiting for irq.\n");
		mdc800->camera_request_ready=0;
		return -2;
	}
	
	return 0;
}


/*
 * The write_urb callback function
 */
static void mdc800_usb_write_notify (struct urb *urb)
{
	struct mdc800_data* mdc800=urb->context;
	int status = urb->status;

	if (status != 0)
		dev_err(&mdc800->dev->dev,
			"writing command fails (status=%i)\n", status);
	else
		mdc800->state=READY;
	mdc800->written = 1;
	wake_up (&mdc800->write_wait);
}


/*
 * The download_urb callback function
 */
static void mdc800_usb_download_notify (struct urb *urb)
{
	struct mdc800_data* mdc800=urb->context;
	int status = urb->status;

	if (status == 0) {
		/* Fill output buffer with these data */
		memcpy (mdc800->out,  urb->transfer_buffer, 64);
		mdc800->out_count=64;
		mdc800->out_ptr=0;
		mdc800->download_left-=64;
		if (mdc800->download_left == 0)
		{
			mdc800->state=READY;
		}
	} else {
		dev_err(&mdc800->dev->dev,
			"request bytes fails (status:%i)\n", status);
	}
	mdc800->downloaded = 1;
	wake_up (&mdc800->download_wait);
}


/***************************************************************************
	Probing for the Camera
 ***************************************************************************/

static struct usb_driver mdc800_usb_driver;
static const struct file_operations mdc800_device_ops;
static struct usb_class_driver mdc800_class = {
	.name =		"mdc800%d",
	.fops =		&mdc800_device_ops,
	.minor_base =	MDC800_DEVICE_MINOR_BASE,
};


/*
 * Callback to search the Mustek MDC800 on the USB Bus
 */
static int mdc800_usb_probe (struct usb_interface *intf,
			       const struct usb_device_id *id)
{
	int i,j;
	struct usb_host_interface *intf_desc;
	struct usb_device *dev = interface_to_usbdev (intf);
	int irq_interval=0;
	int retval;

	dev_dbg(&intf->dev, "(%s) called.\n", __func__);


	if (mdc800->dev != NULL)
	{
		dev_warn(&intf->dev, "only one Mustek MDC800 is supported.\n");
		return -ENODEV;
	}

	if (dev->descriptor.bNumConfigurations != 1)
	{
		dev_err(&intf->dev,
			"probe fails -> wrong Number of Configuration\n");
		return -ENODEV;
	}
	intf_desc = intf->cur_altsetting;

	if (
			( intf_desc->desc.bInterfaceClass != 0xff )
		||	( intf_desc->desc.bInterfaceSubClass != 0 )
		|| ( intf_desc->desc.bInterfaceProtocol != 0 )
		|| ( intf_desc->desc.bNumEndpoints != 4)
	)
	{
		dev_err(&intf->dev, "probe fails -> wrong Interface\n");
		return -ENODEV;
	}

	/* Check the Endpoints */
	for (i=0; i<4; i++)
	{
		mdc800->endpoint[i]=-1;
		for (j=0; j<4; j++)
		{
			if (mdc800_endpoint_equals (&intf_desc->endpoint [j].desc,&mdc800_ed [i]))
			{
				mdc800->endpoint[i]=intf_desc->endpoint [j].desc.bEndpointAddress ;
				if (i==1)
				{
					irq_interval=intf_desc->endpoint [j].desc.bInterval;
				}
			}
		}
		if (mdc800->endpoint[i] == -1)
		{
			dev_err(&intf->dev, "probe fails -> Wrong Endpoints.\n");
			return -ENODEV;
		}
	}


	dev_info(&intf->dev, "Found Mustek MDC800 on USB.\n");

	mutex_lock(&mdc800->io_lock);

	retval = usb_register_dev(intf, &mdc800_class);
	if (retval) {
		dev_err(&intf->dev, "Not able to get a minor for this device.\n");
		mutex_unlock(&mdc800->io_lock);
		return -ENODEV;
	}

	mdc800->dev=dev;
	mdc800->open=0;

	/* Setup URB Structs */
	usb_fill_int_urb (
		mdc800->irq_urb,
		mdc800->dev,
		usb_rcvintpipe (mdc800->dev,mdc800->endpoint [1]),
		mdc800->irq_urb_buffer,
		8,
		mdc800_usb_irq,
		mdc800,
		irq_interval
	);

	usb_fill_bulk_urb (
		mdc800->write_urb,
		mdc800->dev,
		usb_sndbulkpipe (mdc800->dev, mdc800->endpoint[0]),
		mdc800->write_urb_buffer,
		8,
		mdc800_usb_write_notify,
		mdc800
	);

	usb_fill_bulk_urb (
		mdc800->download_urb,
		mdc800->dev,
		usb_rcvbulkpipe (mdc800->dev, mdc800->endpoint [3]),
		mdc800->download_urb_buffer,
		64,
		mdc800_usb_download_notify,
		mdc800
	);

	mdc800->state=READY;

	mutex_unlock(&mdc800->io_lock);
	
	usb_set_intfdata(intf, mdc800);
	return 0;
}


/*
 * Disconnect USB device (maybe the MDC800)
 */
static void mdc800_usb_disconnect (struct usb_interface *intf)
{
	struct mdc800_data* mdc800 = usb_get_intfdata(intf);

	dev_dbg(&intf->dev, "(%s) called\n", __func__);

	if (mdc800) {
		if (mdc800->state == NOT_CONNECTED)
			return;

		usb_deregister_dev(intf, &mdc800_class);

		/* must be under lock to make sure no URB
		   is submitted after usb_kill_urb() */
		mutex_lock(&mdc800->io_lock);
		mdc800->state=NOT_CONNECTED;

		usb_kill_urb(mdc800->irq_urb);
		usb_kill_urb(mdc800->write_urb);
		usb_kill_urb(mdc800->download_urb);
		mutex_unlock(&mdc800->io_lock);

		mdc800->dev = NULL;
		usb_set_intfdata(intf, NULL);
	}
	dev_info(&intf->dev, "Mustek MDC800 disconnected from USB.\n");
}


/***************************************************************************
	The Misc device Part (file_operations)
****************************************************************************/

/*
 * This Function calc the Answersize for a command.
 */
static int mdc800_getAnswerSize (char command)
{
	switch ((unsigned char) command)
	{
		case 0x2a:
		case 0x49:
		case 0x51:
		case 0x0d:
		case 0x20:
		case 0x07:
		case 0x01:
		case 0x25:
		case 0x00:
			return 8;

		case 0x05:
		case 0x3e:
			return mdc800->pic_len;

		case 0x09:
			return 4096;

		default:
			return 0;
	}
}


/*
 * Init the device: (1) alloc mem (2) Increase MOD Count ..
 */
static int mdc800_device_open (struct inode* inode, struct file *file)
{
	int retval=0;
	int errn=0;

	mutex_lock(&mdc800->io_lock);
	
	if (mdc800->state == NOT_CONNECTED)
	{
		errn=-EBUSY;
		goto error_out;
	}
	if (mdc800->open)
	{
		errn=-EBUSY;
		goto error_out;
	}

	mdc800->in_count=0;
	mdc800->out_count=0;
	mdc800->out_ptr=0;
	mdc800->pic_index=0;
	mdc800->pic_len=-1;
	mdc800->download_left=0;

	mdc800->camera_busy=0;
	mdc800->camera_request_ready=0;

	retval=0;
	mdc800->irq_urb->dev = mdc800->dev;
	retval = usb_submit_urb (mdc800->irq_urb, GFP_KERNEL);
	if (retval) {
		dev_err(&mdc800->dev->dev,
			"request USB irq fails (submit_retval=%i).\n", retval);
		errn = -EIO;
		goto error_out;
	}

	mdc800->open=1;
	dev_dbg(&mdc800->dev->dev, "Mustek MDC800 device opened.\n");

error_out:
	mutex_unlock(&mdc800->io_lock);
	return errn;
}


/*
 * Close the Camera and release Memory
 */
static int mdc800_device_release (struct inode* inode, struct file *file)
{
	int retval=0;

	mutex_lock(&mdc800->io_lock);
	if (mdc800->open && (mdc800->state != NOT_CONNECTED))
	{
		usb_kill_urb(mdc800->irq_urb);
		usb_kill_urb(mdc800->write_urb);
		usb_kill_urb(mdc800->download_urb);
		mdc800->open=0;
	}
	else
	{
		retval=-EIO;
	}

	mutex_unlock(&mdc800->io_lock);
	return retval;
}


/*
 * The Device read callback Function
 */
static ssize_t mdc800_device_read (struct file *file, char __user *buf, size_t len, loff_t *pos)
{
	size_t left=len, sts=len; /* single transfer size */
	char __user *ptr = buf;
	int retval;

	mutex_lock(&mdc800->io_lock);
	if (mdc800->state == NOT_CONNECTED)
	{
		mutex_unlock(&mdc800->io_lock);
		return -EBUSY;
	}
	if (mdc800->state == WORKING)
	{
		printk(KERN_WARNING "mdc800: Illegal State \"working\""
		       "reached during read ?!\n");
		mutex_unlock(&mdc800->io_lock);
		return -EBUSY;
	}
	if (!mdc800->open)
	{
		mutex_unlock(&mdc800->io_lock);
		return -EBUSY;
	}

	while (left)
	{
		if (signal_pending (current)) 
		{
			mutex_unlock(&mdc800->io_lock);
			return -EINTR;
		}

		sts=left > (mdc800->out_count-mdc800->out_ptr)?mdc800->out_count-mdc800->out_ptr:left;

		if (sts <= 0)
		{
			/* Too less Data in buffer */
			if (mdc800->state == DOWNLOAD)
			{
				mdc800->out_count=0;
				mdc800->out_ptr=0;

				/* Download -> Request new bytes */
				mdc800->download_urb->dev = mdc800->dev;
				retval = usb_submit_urb (mdc800->download_urb, GFP_KERNEL);
				if (retval) {
					dev_err(&mdc800->dev->dev,
						"Can't submit download urb "
						"(retval=%i)\n", retval);
					mutex_unlock(&mdc800->io_lock);
					return len-left;
				}
				wait_event_timeout(mdc800->download_wait, mdc800->downloaded,
										TO_DOWNLOAD_GET_READY*HZ/1000);
				mdc800->downloaded = 0;
				if (mdc800->download_urb->status != 0)
				{
					dev_err(&mdc800->dev->dev,
						"request download-bytes fails "
						"(status=%i)\n",
						mdc800->download_urb->status);
					mutex_unlock(&mdc800->io_lock);
					return len-left;
				}
			}
			else
			{
				/* No more bytes -> that's an error*/
				mutex_unlock(&mdc800->io_lock);
				return -EIO;
			}
		}
		else
		{
			/* Copy Bytes */
			if (copy_to_user(ptr, &mdc800->out [mdc800->out_ptr],
						sts)) {
				mutex_unlock(&mdc800->io_lock);
				return -EFAULT;
			}
			ptr+=sts;
			left-=sts;
			mdc800->out_ptr+=sts;
		}
	}

	mutex_unlock(&mdc800->io_lock);
	return len-left;
}


/*
 * The Device write callback Function
 * If a 8Byte Command is received, it will be send to the camera.
 * After this the driver initiates the request for the answer or
 * just waits until the camera becomes ready.
 */
static ssize_t mdc800_device_write (struct file *file, const char __user *buf, size_t len, loff_t *pos)
{
	size_t i=0;
	int retval;

	mutex_lock(&mdc800->io_lock);
	if (mdc800->state != READY)
	{
		mutex_unlock(&mdc800->io_lock);
		return -EBUSY;
	}
	if (!mdc800->open )
	{
		mutex_unlock(&mdc800->io_lock);
		return -EBUSY;
	}

	while (i<len)
	{
		unsigned char c;
		if (signal_pending (current)) 
		{
			mutex_unlock(&mdc800->io_lock);
			return -EINTR;
		}
		
		if(get_user(c, buf+i))
		{
			mutex_unlock(&mdc800->io_lock);
			return -EFAULT;
		}

		/* check for command start */
		if (c == 0x55)
		{
			mdc800->in_count=0;
			mdc800->out_count=0;
			mdc800->out_ptr=0;
			mdc800->download_left=0;
		}

		/* save command byte */
		if (mdc800->in_count < 8)
		{
			mdc800->in[mdc800->in_count] = c;
			mdc800->in_count++;
		}
		else
		{
			mutex_unlock(&mdc800->io_lock);
			return -EIO;
		}

		/* Command Buffer full ? -> send it to camera */
		if (mdc800->in_count == 8)
		{
			int answersize;

			if (mdc800_usb_waitForIRQ (0,TO_GET_READY))
			{
				dev_err(&mdc800->dev->dev,
					"Camera didn't get ready.\n");
				mutex_unlock(&mdc800->io_lock);
				return -EIO;
			}

			answersize=mdc800_getAnswerSize (mdc800->in[1]);

			mdc800->state=WORKING;
			memcpy (mdc800->write_urb->transfer_buffer, mdc800->in,8);
			mdc800->write_urb->dev = mdc800->dev;
			retval = usb_submit_urb (mdc800->write_urb, GFP_KERNEL);
			if (retval) {
				dev_err(&mdc800->dev->dev,
					"submitting write urb fails "
					"(retval=%i)\n", retval);
				mutex_unlock(&mdc800->io_lock);
				return -EIO;
			}
			wait_event_timeout(mdc800->write_wait, mdc800->written, TO_WRITE_GET_READY*HZ/1000);
			mdc800->written = 0;
			if (mdc800->state == WORKING)
			{
				usb_kill_urb(mdc800->write_urb);
				mutex_unlock(&mdc800->io_lock);
				return -EIO;
			}

			switch ((unsigned char) mdc800->in[1])
			{
				case 0x05: /* Download Image */
				case 0x3e: /* Take shot in Fine Mode (WCam Mode) */
					if (mdc800->pic_len < 0)
					{
						dev_err(&mdc800->dev->dev,
							"call 0x07 before "
							"0x05,0x3e\n");
						mdc800->state=READY;
						mutex_unlock(&mdc800->io_lock);
						return -EIO;
					}
					mdc800->pic_len=-1;

				case 0x09: /* Download Thumbnail */
					mdc800->download_left=answersize+64;
					mdc800->state=DOWNLOAD;
					mdc800_usb_waitForIRQ (0,TO_DOWNLOAD_GET_BUSY);
					break;


				default:
					if (answersize)
					{

						if (mdc800_usb_waitForIRQ (1,TO_READ_FROM_IRQ))
						{
							dev_err(&mdc800->dev->dev, "requesting answer from irq fails\n");
							mutex_unlock(&mdc800->io_lock);
							return -EIO;
						}

						/* Write dummy data, (this is ugly but part of the USB Protocol */
						/* if you use endpoint 1 as bulk and not as irq) */
						memcpy (mdc800->out, mdc800->camera_response,8);

						/* This is the interpreted answer */
						memcpy (&mdc800->out[8], mdc800->camera_response,8);

						mdc800->out_ptr=0;
						mdc800->out_count=16;

						/* Cache the Imagesize, if command was getImageSize */
						if (mdc800->in [1] == (char) 0x07)
						{
							mdc800->pic_len=(int) 65536*(unsigned char) mdc800->camera_response[0]+256*(unsigned char) mdc800->camera_response[1]+(unsigned char) mdc800->camera_response[2];

							dev_dbg(&mdc800->dev->dev, "cached imagesize = %i\n", mdc800->pic_len);
						}

					}
					else
					{
						if (mdc800_usb_waitForIRQ (0,TO_DEFAULT_COMMAND))
						{
							dev_err(&mdc800->dev->dev, "Command Timeout.\n");
							mutex_unlock(&mdc800->io_lock);
							return -EIO;
						}
					}
					mdc800->state=READY;
					break;
			}
		}
		i++;
	}
	mutex_unlock(&mdc800->io_lock);
	return i;
}


/***************************************************************************
	Init and Cleanup this driver (Structs and types)
****************************************************************************/

/* File Operations of this drivers */
static const struct file_operations mdc800_device_ops =
{
	.owner =	THIS_MODULE,
	.read =		mdc800_device_read,
	.write =	mdc800_device_write,
	.open =		mdc800_device_open,
	.release =	mdc800_device_release,
	.llseek =	noop_llseek,
};



static const struct usb_device_id mdc800_table[] = {
	{ USB_DEVICE(MDC800_VENDOR_ID, MDC800_PRODUCT_ID) },
	{ }						/* Terminating entry */
};

MODULE_DEVICE_TABLE (usb, mdc800_table);
/*
 * USB Driver Struct for this device
 */
static struct usb_driver mdc800_usb_driver =
{
	.name =		"mdc800",
	.probe =	mdc800_usb_probe,
	.disconnect =	mdc800_usb_disconnect,
	.id_table =	mdc800_table
};



/************************************************************************
	Init and Cleanup this driver (Main Functions)
*************************************************************************/

static int __init usb_mdc800_init (void)
{
	int retval = -ENODEV;
	/* Allocate Memory */
	mdc800=kzalloc (sizeof (struct mdc800_data), GFP_KERNEL);
	if (!mdc800)
		goto cleanup_on_fail;

	mdc800->dev = NULL;
	mdc800->state=NOT_CONNECTED;
	mutex_init (&mdc800->io_lock);

	init_waitqueue_head (&mdc800->irq_wait);
	init_waitqueue_head (&mdc800->write_wait);
	init_waitqueue_head (&mdc800->download_wait);

	mdc800->irq_woken = 0;
	mdc800->downloaded = 0;
	mdc800->written = 0;

	mdc800->irq_urb_buffer=kmalloc (8, GFP_KERNEL);
	if (!mdc800->irq_urb_buffer)
		goto cleanup_on_fail;
	mdc800->write_urb_buffer=kmalloc (8, GFP_KERNEL);
	if (!mdc800->write_urb_buffer)
		goto cleanup_on_fail;
	mdc800->download_urb_buffer=kmalloc (64, GFP_KERNEL);
	if (!mdc800->download_urb_buffer)
		goto cleanup_on_fail;

	mdc800->irq_urb=usb_alloc_urb (0, GFP_KERNEL);
	if (!mdc800->irq_urb)
		goto cleanup_on_fail;
	mdc800->download_urb=usb_alloc_urb (0, GFP_KERNEL);
	if (!mdc800->download_urb)
		goto cleanup_on_fail;
	mdc800->write_urb=usb_alloc_urb (0, GFP_KERNEL);
	if (!mdc800->write_urb)
		goto cleanup_on_fail;

	/* Register the driver */
	retval = usb_register(&mdc800_usb_driver);
	if (retval)
		goto cleanup_on_fail;

	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
	       DRIVER_DESC "\n");

	return 0;

	/* Clean driver up, when something fails */

cleanup_on_fail:

	if (mdc800 != NULL)
	{
		printk(KERN_ERR "mdc800: can't alloc memory!\n");

		kfree(mdc800->download_urb_buffer);
		kfree(mdc800->write_urb_buffer);
		kfree(mdc800->irq_urb_buffer);

		usb_free_urb(mdc800->write_urb);
		usb_free_urb(mdc800->download_urb);
		usb_free_urb(mdc800->irq_urb);

		kfree (mdc800);
	}
	mdc800 = NULL;
	return retval;
}


static void __exit usb_mdc800_cleanup (void)
{
	usb_deregister (&mdc800_usb_driver);

	usb_free_urb (mdc800->irq_urb);
	usb_free_urb (mdc800->download_urb);
	usb_free_urb (mdc800->write_urb);

	kfree (mdc800->irq_urb_buffer);
	kfree (mdc800->write_urb_buffer);
	kfree (mdc800->download_urb_buffer);

	kfree (mdc800);
	mdc800 = NULL;
}

module_init (usb_mdc800_init);
module_exit (usb_mdc800_cleanup);

MODULE_AUTHOR( DRIVER_AUTHOR );
MODULE_DESCRIPTION( DRIVER_DESC );
MODULE_LICENSE("GPL");