xref: /linux/drivers/usb/image/mdc800.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
1 /*
2  * copyright (C) 1999/2000 by Henning Zabel <henning@uni-paderborn.de>
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms of the GNU General Public License as published by the
6  * Free Software Foundation; either version 2 of the License, or (at your
7  * option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful, but
10  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
11  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
12  * for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software Foundation,
16  * Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
17  */
18 
19 
20 /*
21  *	USB-Kernel Driver for the Mustek MDC800 Digital Camera
22  *	(c) 1999/2000 Henning Zabel <henning@uni-paderborn.de>
23  *
24  *
25  * The driver brings the USB functions of the MDC800 to Linux.
26  * To use the Camera you must support the USB Protocol of the camera
27  * to the Kernel Node.
28  * The Driver uses a misc device Node. Create it with :
29  * mknod /dev/mustek c 180 32
30  *
31  * The driver supports only one camera.
32  *
33  * Fix: mdc800 used sleep_on and slept with io_lock held.
34  * Converted sleep_on to waitqueues with schedule_timeout and made io_lock
35  * a semaphore from a spinlock.
36  * by Oliver Neukum <oliver@neukum.name>
37  * (02/12/2001)
38  *
39  * Identify version on module load.
40  * (08/04/2001) gb
41  *
42  * version 0.7.5
43  * Fixed potential SMP races with Spinlocks.
44  * Thanks to Oliver Neukum <oliver@neukum.name> who
45  * noticed the race conditions.
46  * (30/10/2000)
47  *
48  * Fixed: Setting urb->dev before submitting urb.
49  * by Greg KH <greg@kroah.com>
50  * (13/10/2000)
51  *
52  * version 0.7.3
53  * bugfix : The mdc800->state field gets set to READY after the
54  * the diconnect function sets it to NOT_CONNECTED. This makes the
55  * driver running like the camera is connected and causes some
56  * hang ups.
57  *
58  * version 0.7.1
59  * MOD_INC and MOD_DEC are changed in usb_probe to prevent load/unload
60  * problems when compiled as Module.
61  * (04/04/2000)
62  *
63  * The mdc800 driver gets assigned the USB Minor 32-47. The Registration
64  * was updated to use these values.
65  * (26/03/2000)
66  *
67  * The Init und Exit Module Function are updated.
68  * (01/03/2000)
69  *
70  * version 0.7.0
71  * Rewrite of the driver : The driver now uses URB's. The old stuff
72  * has been removed.
73  *
74  * version 0.6.0
75  * Rewrite of this driver: The Emulation of the rs232 protocoll
76  * has been removed from the driver. A special executeCommand function
77  * for this driver is included to gphoto.
78  * The driver supports two kind of communication to bulk endpoints.
79  * Either with the dev->bus->ops->bulk... or with callback function.
80  * (09/11/1999)
81  *
82  * version 0.5.0:
83  * first Version that gets a version number. Most of the needed
84  * functions work.
85  * (20/10/1999)
86  */
87 
88 #include <linux/sched.h>
89 #include <linux/signal.h>
90 #include <linux/spinlock.h>
91 #include <linux/errno.h>
92 #include <linux/random.h>
93 #include <linux/poll.h>
94 #include <linux/init.h>
95 #include <linux/slab.h>
96 #include <linux/module.h>
97 #include <linux/smp_lock.h>
98 #include <linux/wait.h>
99 #include <linux/mutex.h>
100 
101 #include <linux/usb.h>
102 #include <linux/fs.h>
103 
104 /*
105  * Version Information
106  */
107 #define DRIVER_VERSION "v0.7.5 (30/10/2000)"
108 #define DRIVER_AUTHOR "Henning Zabel <henning@uni-paderborn.de>"
109 #define DRIVER_DESC "USB Driver for Mustek MDC800 Digital Camera"
110 
111 /* Vendor and Product Information */
112 #define MDC800_VENDOR_ID 	0x055f
113 #define MDC800_PRODUCT_ID	0xa800
114 
115 /* Timeouts (msec) */
116 #define TO_DOWNLOAD_GET_READY		1500
117 #define TO_DOWNLOAD_GET_BUSY		1500
118 #define TO_WRITE_GET_READY		1000
119 #define TO_DEFAULT_COMMAND		5000
120 #define TO_READ_FROM_IRQ 		TO_DEFAULT_COMMAND
121 #define TO_GET_READY			TO_DEFAULT_COMMAND
122 
123 /* Minor Number of the device (create with mknod /dev/mustek c 180 32) */
124 #define MDC800_DEVICE_MINOR_BASE 32
125 
126 
127 /**************************************************************************
128 	Data and structs
129 ***************************************************************************/
130 
131 
132 typedef enum {
133 	NOT_CONNECTED, READY, WORKING, DOWNLOAD
134 } mdc800_state;
135 
136 
137 /* Data for the driver */
138 struct mdc800_data
139 {
140 	struct usb_device *	dev;			// Device Data
141 	mdc800_state 		state;
142 
143 	unsigned int		endpoint [4];
144 
145 	struct urb *		irq_urb;
146 	wait_queue_head_t	irq_wait;
147 	int			irq_woken;
148 	char*			irq_urb_buffer;
149 
150 	int			camera_busy;          // is camera busy ?
151 	int 			camera_request_ready; // Status to synchronize with irq
152 	char 			camera_response [8];  // last Bytes send after busy
153 
154 	struct urb *   		write_urb;
155 	char*			write_urb_buffer;
156 	wait_queue_head_t	write_wait;
157 	int			written;
158 
159 
160 	struct urb *   		download_urb;
161 	char*			download_urb_buffer;
162 	wait_queue_head_t	download_wait;
163 	int			downloaded;
164 	int			download_left;		// Bytes left to download ?
165 
166 
167 	/* Device Data */
168 	char			out [64];	// Answer Buffer
169 	int 			out_ptr;	// Index to the first not readen byte
170 	int			out_count;	// Bytes in the buffer
171 
172 	int			open;		// Camera device open ?
173 	struct mutex		io_lock;	// IO -lock
174 
175 	char 			in [8];		// Command Input Buffer
176 	int  			in_count;
177 
178 	int			pic_index;	// Cache for the Imagesize (-1 for nothing cached )
179 	int			pic_len;
180 	int			minor;
181 };
182 
183 
184 /* Specification of the Endpoints */
185 static struct usb_endpoint_descriptor mdc800_ed [4] =
186 {
187 	{
188 		.bLength = 		0,
189 		.bDescriptorType =	0,
190 		.bEndpointAddress =	0x01,
191 		.bmAttributes = 	0x02,
192 		.wMaxPacketSize =	__constant_cpu_to_le16(8),
193 		.bInterval = 		0,
194 		.bRefresh = 		0,
195 		.bSynchAddress = 	0,
196 	},
197 	{
198 		.bLength = 		0,
199 		.bDescriptorType = 	0,
200 		.bEndpointAddress = 	0x82,
201 		.bmAttributes = 	0x03,
202 		.wMaxPacketSize = 	__constant_cpu_to_le16(8),
203 		.bInterval = 		0,
204 		.bRefresh = 		0,
205 		.bSynchAddress = 	0,
206 	},
207 	{
208 		.bLength = 		0,
209 		.bDescriptorType = 	0,
210 		.bEndpointAddress = 	0x03,
211 		.bmAttributes = 	0x02,
212 		.wMaxPacketSize = 	__constant_cpu_to_le16(64),
213 		.bInterval = 		0,
214 		.bRefresh = 		0,
215 		.bSynchAddress = 	0,
216 	},
217 	{
218 		.bLength = 		0,
219 		.bDescriptorType = 	0,
220 		.bEndpointAddress = 	0x84,
221 		.bmAttributes = 	0x02,
222 		.wMaxPacketSize = 	__constant_cpu_to_le16(64),
223 		.bInterval = 		0,
224 		.bRefresh = 		0,
225 		.bSynchAddress = 	0,
226 	},
227 };
228 
229 /* The Variable used by the driver */
230 static struct mdc800_data* mdc800;
231 
232 
233 /***************************************************************************
234 	The USB Part of the driver
235 ****************************************************************************/
236 
237 static int mdc800_endpoint_equals (struct usb_endpoint_descriptor *a,struct usb_endpoint_descriptor *b)
238 {
239 	return (
240 		   ( a->bEndpointAddress == b->bEndpointAddress )
241 		&& ( a->bmAttributes     == b->bmAttributes     )
242 		&& ( a->wMaxPacketSize   == b->wMaxPacketSize   )
243 	);
244 }
245 
246 
247 /*
248  * Checks whether the camera responds busy
249  */
250 static int mdc800_isBusy (char* ch)
251 {
252 	int i=0;
253 	while (i<8)
254 	{
255 		if (ch [i] != (char)0x99)
256 			return 0;
257 		i++;
258 	}
259 	return 1;
260 }
261 
262 
263 /*
264  * Checks whether the Camera is ready
265  */
266 static int mdc800_isReady (char *ch)
267 {
268 	int i=0;
269 	while (i<8)
270 	{
271 		if (ch [i] != (char)0xbb)
272 			return 0;
273 		i++;
274 	}
275 	return 1;
276 }
277 
278 
279 
280 /*
281  * USB IRQ Handler for InputLine
282  */
283 static void mdc800_usb_irq (struct urb *urb)
284 {
285 	int data_received=0, wake_up;
286 	unsigned char* b=urb->transfer_buffer;
287 	struct mdc800_data* mdc800=urb->context;
288 
289 	if (urb->status >= 0)
290 	{
291 
292 		//dbg ("%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]);
293 
294 		if (mdc800_isBusy (b))
295 		{
296 			if (!mdc800->camera_busy)
297 			{
298 				mdc800->camera_busy=1;
299 				dbg ("gets busy");
300 			}
301 		}
302 		else
303 		{
304 			if (mdc800->camera_busy && mdc800_isReady (b))
305 			{
306 				mdc800->camera_busy=0;
307 				dbg ("gets ready");
308 			}
309 		}
310 		if (!(mdc800_isBusy (b) || mdc800_isReady (b)))
311 		{
312 			/* Store Data in camera_answer field */
313 			dbg ("%i %i %i %i %i %i %i %i ",b[0],b[1],b[2],b[3],b[4],b[5],b[6],b[7]);
314 
315 			memcpy (mdc800->camera_response,b,8);
316 			data_received=1;
317 		}
318 	}
319 	wake_up= ( mdc800->camera_request_ready > 0 )
320 		&&
321 		(
322 			((mdc800->camera_request_ready == 1) && (!mdc800->camera_busy))
323 		||
324 			((mdc800->camera_request_ready == 2) && data_received)
325 		||
326 			((mdc800->camera_request_ready == 3) && (mdc800->camera_busy))
327 		||
328 			(urb->status < 0)
329 		);
330 
331 	if (wake_up)
332 	{
333 		mdc800->camera_request_ready=0;
334 		mdc800->irq_woken=1;
335 		wake_up (&mdc800->irq_wait);
336 	}
337 }
338 
339 
340 /*
341  * Waits a while until the irq responds that camera is ready
342  *
343  *  mode : 0: Wait for camera gets ready
344  *         1: Wait for receiving data
345  *         2: Wait for camera gets busy
346  *
347  * msec: Time to wait
348  */
349 static int mdc800_usb_waitForIRQ (int mode, int msec)
350 {
351 	mdc800->camera_request_ready=1+mode;
352 
353 	wait_event_timeout(mdc800->irq_wait, mdc800->irq_woken, msec*HZ/1000);
354 	mdc800->irq_woken = 0;
355 
356 	if (mdc800->camera_request_ready>0)
357 	{
358 		mdc800->camera_request_ready=0;
359 		err ("timeout waiting for camera.");
360 		return -1;
361 	}
362 
363 	if (mdc800->state == NOT_CONNECTED)
364 	{
365 		warn ("Camera gets disconnected during waiting for irq.");
366 		mdc800->camera_request_ready=0;
367 		return -2;
368 	}
369 
370 	return 0;
371 }
372 
373 
374 /*
375  * The write_urb callback function
376  */
377 static void mdc800_usb_write_notify (struct urb *urb)
378 {
379 	struct mdc800_data* mdc800=urb->context;
380 
381 	if (urb->status != 0)
382 	{
383 		err ("writing command fails (status=%i)", urb->status);
384 	}
385 	else
386 	{
387 		mdc800->state=READY;
388 	}
389 	mdc800->written = 1;
390 	wake_up (&mdc800->write_wait);
391 }
392 
393 
394 /*
395  * The download_urb callback function
396  */
397 static void mdc800_usb_download_notify (struct urb *urb)
398 {
399 	struct mdc800_data* mdc800=urb->context;
400 
401 	if (urb->status == 0)
402 	{
403 		/* Fill output buffer with these data */
404 		memcpy (mdc800->out,  urb->transfer_buffer, 64);
405 		mdc800->out_count=64;
406 		mdc800->out_ptr=0;
407 		mdc800->download_left-=64;
408 		if (mdc800->download_left == 0)
409 		{
410 			mdc800->state=READY;
411 		}
412 	}
413 	else
414 	{
415 		err ("request bytes fails (status:%i)", urb->status);
416 	}
417 	mdc800->downloaded = 1;
418 	wake_up (&mdc800->download_wait);
419 }
420 
421 
422 /***************************************************************************
423 	Probing for the Camera
424  ***************************************************************************/
425 
426 static struct usb_driver mdc800_usb_driver;
427 static const struct file_operations mdc800_device_ops;
428 static struct usb_class_driver mdc800_class = {
429 	.name =		"mdc800%d",
430 	.fops =		&mdc800_device_ops,
431 	.minor_base =	MDC800_DEVICE_MINOR_BASE,
432 };
433 
434 
435 /*
436  * Callback to search the Mustek MDC800 on the USB Bus
437  */
438 static int mdc800_usb_probe (struct usb_interface *intf,
439 			       const struct usb_device_id *id)
440 {
441 	int i,j;
442 	struct usb_host_interface *intf_desc;
443 	struct usb_device *dev = interface_to_usbdev (intf);
444 	int irq_interval=0;
445 	int retval;
446 
447 	dbg ("(mdc800_usb_probe) called.");
448 
449 
450 	if (mdc800->dev != NULL)
451 	{
452 		warn ("only one Mustek MDC800 is supported.");
453 		return -ENODEV;
454 	}
455 
456 	if (dev->descriptor.bNumConfigurations != 1)
457 	{
458 		err ("probe fails -> wrong Number of Configuration");
459 		return -ENODEV;
460 	}
461 	intf_desc = intf->cur_altsetting;
462 
463 	if (
464 			( intf_desc->desc.bInterfaceClass != 0xff )
465 		||	( intf_desc->desc.bInterfaceSubClass != 0 )
466 		|| ( intf_desc->desc.bInterfaceProtocol != 0 )
467 		|| ( intf_desc->desc.bNumEndpoints != 4)
468 	)
469 	{
470 		err ("probe fails -> wrong Interface");
471 		return -ENODEV;
472 	}
473 
474 	/* Check the Endpoints */
475 	for (i=0; i<4; i++)
476 	{
477 		mdc800->endpoint[i]=-1;
478 		for (j=0; j<4; j++)
479 		{
480 			if (mdc800_endpoint_equals (&intf_desc->endpoint [j].desc,&mdc800_ed [i]))
481 			{
482 				mdc800->endpoint[i]=intf_desc->endpoint [j].desc.bEndpointAddress ;
483 				if (i==1)
484 				{
485 					irq_interval=intf_desc->endpoint [j].desc.bInterval;
486 				}
487 
488 				continue;
489 			}
490 		}
491 		if (mdc800->endpoint[i] == -1)
492 		{
493 			err ("probe fails -> Wrong Endpoints.");
494 			return -ENODEV;
495 		}
496 	}
497 
498 
499 	info ("Found Mustek MDC800 on USB.");
500 
501 	mutex_lock(&mdc800->io_lock);
502 
503 	retval = usb_register_dev(intf, &mdc800_class);
504 	if (retval) {
505 		err ("Not able to get a minor for this device.");
506 		return -ENODEV;
507 	}
508 
509 	mdc800->dev=dev;
510 	mdc800->open=0;
511 
512 	/* Setup URB Structs */
513 	usb_fill_int_urb (
514 		mdc800->irq_urb,
515 		mdc800->dev,
516 		usb_rcvintpipe (mdc800->dev,mdc800->endpoint [1]),
517 		mdc800->irq_urb_buffer,
518 		8,
519 		mdc800_usb_irq,
520 		mdc800,
521 		irq_interval
522 	);
523 
524 	usb_fill_bulk_urb (
525 		mdc800->write_urb,
526 		mdc800->dev,
527 		usb_sndbulkpipe (mdc800->dev, mdc800->endpoint[0]),
528 		mdc800->write_urb_buffer,
529 		8,
530 		mdc800_usb_write_notify,
531 		mdc800
532 	);
533 
534 	usb_fill_bulk_urb (
535 		mdc800->download_urb,
536 		mdc800->dev,
537 		usb_rcvbulkpipe (mdc800->dev, mdc800->endpoint [3]),
538 		mdc800->download_urb_buffer,
539 		64,
540 		mdc800_usb_download_notify,
541 		mdc800
542 	);
543 
544 	mdc800->state=READY;
545 
546 	mutex_unlock(&mdc800->io_lock);
547 
548 	usb_set_intfdata(intf, mdc800);
549 	return 0;
550 }
551 
552 
553 /*
554  * Disconnect USB device (maybe the MDC800)
555  */
556 static void mdc800_usb_disconnect (struct usb_interface *intf)
557 {
558 	struct mdc800_data* mdc800 = usb_get_intfdata(intf);
559 
560 	dbg ("(mdc800_usb_disconnect) called");
561 
562 	if (mdc800) {
563 		if (mdc800->state == NOT_CONNECTED)
564 			return;
565 
566 		usb_deregister_dev(intf, &mdc800_class);
567 
568 		/* must be under lock to make sure no URB
569 		   is submitted after usb_kill_urb() */
570 		mutex_lock(&mdc800->io_lock);
571 		mdc800->state=NOT_CONNECTED;
572 
573 		usb_kill_urb(mdc800->irq_urb);
574 		usb_kill_urb(mdc800->write_urb);
575 		usb_kill_urb(mdc800->download_urb);
576 		mutex_unlock(&mdc800->io_lock);
577 
578 		mdc800->dev = NULL;
579 		usb_set_intfdata(intf, NULL);
580 	}
581 	info ("Mustek MDC800 disconnected from USB.");
582 }
583 
584 
585 /***************************************************************************
586 	The Misc device Part (file_operations)
587 ****************************************************************************/
588 
589 /*
590  * This Function calc the Answersize for a command.
591  */
592 static int mdc800_getAnswerSize (char command)
593 {
594 	switch ((unsigned char) command)
595 	{
596 		case 0x2a:
597 		case 0x49:
598 		case 0x51:
599 		case 0x0d:
600 		case 0x20:
601 		case 0x07:
602 		case 0x01:
603 		case 0x25:
604 		case 0x00:
605 			return 8;
606 
607 		case 0x05:
608 		case 0x3e:
609 			return mdc800->pic_len;
610 
611 		case 0x09:
612 			return 4096;
613 
614 		default:
615 			return 0;
616 	}
617 }
618 
619 
620 /*
621  * Init the device: (1) alloc mem (2) Increase MOD Count ..
622  */
623 static int mdc800_device_open (struct inode* inode, struct file *file)
624 {
625 	int retval=0;
626 	int errn=0;
627 
628 	mutex_lock(&mdc800->io_lock);
629 
630 	if (mdc800->state == NOT_CONNECTED)
631 	{
632 		errn=-EBUSY;
633 		goto error_out;
634 	}
635 	if (mdc800->open)
636 	{
637 		errn=-EBUSY;
638 		goto error_out;
639 	}
640 
641 	mdc800->in_count=0;
642 	mdc800->out_count=0;
643 	mdc800->out_ptr=0;
644 	mdc800->pic_index=0;
645 	mdc800->pic_len=-1;
646 	mdc800->download_left=0;
647 
648 	mdc800->camera_busy=0;
649 	mdc800->camera_request_ready=0;
650 
651 	retval=0;
652 	mdc800->irq_urb->dev = mdc800->dev;
653 	if (usb_submit_urb (mdc800->irq_urb, GFP_KERNEL))
654 	{
655 		err ("request USB irq fails (submit_retval=%i urb_status=%i).",retval, mdc800->irq_urb->status);
656 		errn = -EIO;
657 		goto error_out;
658 	}
659 
660 	mdc800->open=1;
661 	dbg ("Mustek MDC800 device opened.");
662 
663 error_out:
664 	mutex_unlock(&mdc800->io_lock);
665 	return errn;
666 }
667 
668 
669 /*
670  * Close the Camera and release Memory
671  */
672 static int mdc800_device_release (struct inode* inode, struct file *file)
673 {
674 	int retval=0;
675 	dbg ("Mustek MDC800 device closed.");
676 
677 	mutex_lock(&mdc800->io_lock);
678 	if (mdc800->open && (mdc800->state != NOT_CONNECTED))
679 	{
680 		usb_kill_urb(mdc800->irq_urb);
681 		usb_kill_urb(mdc800->write_urb);
682 		usb_kill_urb(mdc800->download_urb);
683 		mdc800->open=0;
684 	}
685 	else
686 	{
687 		retval=-EIO;
688 	}
689 
690 	mutex_unlock(&mdc800->io_lock);
691 	return retval;
692 }
693 
694 
695 /*
696  * The Device read callback Function
697  */
698 static ssize_t mdc800_device_read (struct file *file, char __user *buf, size_t len, loff_t *pos)
699 {
700 	size_t left=len, sts=len; /* single transfer size */
701 	char __user *ptr = buf;
702 
703 	mutex_lock(&mdc800->io_lock);
704 	if (mdc800->state == NOT_CONNECTED)
705 	{
706 		mutex_unlock(&mdc800->io_lock);
707 		return -EBUSY;
708 	}
709 	if (mdc800->state == WORKING)
710 	{
711 		warn ("Illegal State \"working\" reached during read ?!");
712 		mutex_unlock(&mdc800->io_lock);
713 		return -EBUSY;
714 	}
715 	if (!mdc800->open)
716 	{
717 		mutex_unlock(&mdc800->io_lock);
718 		return -EBUSY;
719 	}
720 
721 	while (left)
722 	{
723 		if (signal_pending (current))
724 		{
725 			mutex_unlock(&mdc800->io_lock);
726 			return -EINTR;
727 		}
728 
729 		sts=left > (mdc800->out_count-mdc800->out_ptr)?mdc800->out_count-mdc800->out_ptr:left;
730 
731 		if (sts <= 0)
732 		{
733 			/* Too less Data in buffer */
734 			if (mdc800->state == DOWNLOAD)
735 			{
736 				mdc800->out_count=0;
737 				mdc800->out_ptr=0;
738 
739 				/* Download -> Request new bytes */
740 				mdc800->download_urb->dev = mdc800->dev;
741 				if (usb_submit_urb (mdc800->download_urb, GFP_KERNEL))
742 				{
743 					err ("Can't submit download urb (status=%i)",mdc800->download_urb->status);
744 					mutex_unlock(&mdc800->io_lock);
745 					return len-left;
746 				}
747 				wait_event_timeout(mdc800->download_wait, mdc800->downloaded,
748 										TO_DOWNLOAD_GET_READY*HZ/1000);
749 				mdc800->downloaded = 0;
750 				if (mdc800->download_urb->status != 0)
751 				{
752 					err ("request download-bytes fails (status=%i)",mdc800->download_urb->status);
753 					mutex_unlock(&mdc800->io_lock);
754 					return len-left;
755 				}
756 			}
757 			else
758 			{
759 				/* No more bytes -> that's an error*/
760 				mutex_unlock(&mdc800->io_lock);
761 				return -EIO;
762 			}
763 		}
764 		else
765 		{
766 			/* Copy Bytes */
767 			if (copy_to_user(ptr, &mdc800->out [mdc800->out_ptr],
768 						sts)) {
769 				mutex_unlock(&mdc800->io_lock);
770 				return -EFAULT;
771 			}
772 			ptr+=sts;
773 			left-=sts;
774 			mdc800->out_ptr+=sts;
775 		}
776 	}
777 
778 	mutex_unlock(&mdc800->io_lock);
779 	return len-left;
780 }
781 
782 
783 /*
784  * The Device write callback Function
785  * If a 8Byte Command is received, it will be send to the camera.
786  * After this the driver initiates the request for the answer or
787  * just waits until the camera becomes ready.
788  */
789 static ssize_t mdc800_device_write (struct file *file, const char __user *buf, size_t len, loff_t *pos)
790 {
791 	size_t i=0;
792 
793 	mutex_lock(&mdc800->io_lock);
794 	if (mdc800->state != READY)
795 	{
796 		mutex_unlock(&mdc800->io_lock);
797 		return -EBUSY;
798 	}
799 	if (!mdc800->open )
800 	{
801 		mutex_unlock(&mdc800->io_lock);
802 		return -EBUSY;
803 	}
804 
805 	while (i<len)
806 	{
807 		unsigned char c;
808 		if (signal_pending (current))
809 		{
810 			mutex_unlock(&mdc800->io_lock);
811 			return -EINTR;
812 		}
813 
814 		if(get_user(c, buf+i))
815 		{
816 			mutex_unlock(&mdc800->io_lock);
817 			return -EFAULT;
818 		}
819 
820 		/* check for command start */
821 		if (c == 0x55)
822 		{
823 			mdc800->in_count=0;
824 			mdc800->out_count=0;
825 			mdc800->out_ptr=0;
826 			mdc800->download_left=0;
827 		}
828 
829 		/* save command byte */
830 		if (mdc800->in_count < 8)
831 		{
832 			mdc800->in[mdc800->in_count] = c;
833 			mdc800->in_count++;
834 		}
835 		else
836 		{
837 			mutex_unlock(&mdc800->io_lock);
838 			return -EIO;
839 		}
840 
841 		/* Command Buffer full ? -> send it to camera */
842 		if (mdc800->in_count == 8)
843 		{
844 			int answersize;
845 
846 			if (mdc800_usb_waitForIRQ (0,TO_GET_READY))
847 			{
848 				err ("Camera didn't get ready.\n");
849 				mutex_unlock(&mdc800->io_lock);
850 				return -EIO;
851 			}
852 
853 			answersize=mdc800_getAnswerSize (mdc800->in[1]);
854 
855 			mdc800->state=WORKING;
856 			memcpy (mdc800->write_urb->transfer_buffer, mdc800->in,8);
857 			mdc800->write_urb->dev = mdc800->dev;
858 			if (usb_submit_urb (mdc800->write_urb, GFP_KERNEL))
859 			{
860 				err ("submitting write urb fails (status=%i)", mdc800->write_urb->status);
861 				mutex_unlock(&mdc800->io_lock);
862 				return -EIO;
863 			}
864 			wait_event_timeout(mdc800->write_wait, mdc800->written, TO_WRITE_GET_READY*HZ/1000);
865 			mdc800->written = 0;
866 			if (mdc800->state == WORKING)
867 			{
868 				usb_kill_urb(mdc800->write_urb);
869 				mutex_unlock(&mdc800->io_lock);
870 				return -EIO;
871 			}
872 
873 			switch ((unsigned char) mdc800->in[1])
874 			{
875 				case 0x05: /* Download Image */
876 				case 0x3e: /* Take shot in Fine Mode (WCam Mode) */
877 					if (mdc800->pic_len < 0)
878 					{
879 						err ("call 0x07 before 0x05,0x3e");
880 						mdc800->state=READY;
881 						mutex_unlock(&mdc800->io_lock);
882 						return -EIO;
883 					}
884 					mdc800->pic_len=-1;
885 
886 				case 0x09: /* Download Thumbnail */
887 					mdc800->download_left=answersize+64;
888 					mdc800->state=DOWNLOAD;
889 					mdc800_usb_waitForIRQ (0,TO_DOWNLOAD_GET_BUSY);
890 					break;
891 
892 
893 				default:
894 					if (answersize)
895 					{
896 
897 						if (mdc800_usb_waitForIRQ (1,TO_READ_FROM_IRQ))
898 						{
899 							err ("requesting answer from irq fails");
900 							mutex_unlock(&mdc800->io_lock);
901 							return -EIO;
902 						}
903 
904 						/* Write dummy data, (this is ugly but part of the USB Protocol */
905 						/* if you use endpoint 1 as bulk and not as irq) */
906 						memcpy (mdc800->out, mdc800->camera_response,8);
907 
908 						/* This is the interpreted answer */
909 						memcpy (&mdc800->out[8], mdc800->camera_response,8);
910 
911 						mdc800->out_ptr=0;
912 						mdc800->out_count=16;
913 
914 						/* Cache the Imagesize, if command was getImageSize */
915 						if (mdc800->in [1] == (char) 0x07)
916 						{
917 							mdc800->pic_len=(int) 65536*(unsigned char) mdc800->camera_response[0]+256*(unsigned char) mdc800->camera_response[1]+(unsigned char) mdc800->camera_response[2];
918 
919 							dbg ("cached imagesize = %i",mdc800->pic_len);
920 						}
921 
922 					}
923 					else
924 					{
925 						if (mdc800_usb_waitForIRQ (0,TO_DEFAULT_COMMAND))
926 						{
927 							err ("Command Timeout.");
928 							mutex_unlock(&mdc800->io_lock);
929 							return -EIO;
930 						}
931 					}
932 					mdc800->state=READY;
933 					break;
934 			}
935 		}
936 		i++;
937 	}
938 	mutex_unlock(&mdc800->io_lock);
939 	return i;
940 }
941 
942 
943 /***************************************************************************
944 	Init and Cleanup this driver (Structs and types)
945 ****************************************************************************/
946 
947 /* File Operations of this drivers */
948 static const struct file_operations mdc800_device_ops =
949 {
950 	.owner =	THIS_MODULE,
951 	.read =		mdc800_device_read,
952 	.write =	mdc800_device_write,
953 	.open =		mdc800_device_open,
954 	.release =	mdc800_device_release,
955 };
956 
957 
958 
959 static struct usb_device_id mdc800_table [] = {
960 	{ USB_DEVICE(MDC800_VENDOR_ID, MDC800_PRODUCT_ID) },
961 	{ }						/* Terminating entry */
962 };
963 
964 MODULE_DEVICE_TABLE (usb, mdc800_table);
965 /*
966  * USB Driver Struct for this device
967  */
968 static struct usb_driver mdc800_usb_driver =
969 {
970 	.name =		"mdc800",
971 	.probe =	mdc800_usb_probe,
972 	.disconnect =	mdc800_usb_disconnect,
973 	.id_table =	mdc800_table
974 };
975 
976 
977 
978 /************************************************************************
979 	Init and Cleanup this driver (Main Functions)
980 *************************************************************************/
981 
982 static int __init usb_mdc800_init (void)
983 {
984 	int retval = -ENODEV;
985 	/* Allocate Memory */
986 	mdc800=kzalloc (sizeof (struct mdc800_data), GFP_KERNEL);
987 	if (!mdc800)
988 		goto cleanup_on_fail;
989 
990 	mdc800->dev = NULL;
991 	mdc800->state=NOT_CONNECTED;
992 	mutex_init (&mdc800->io_lock);
993 
994 	init_waitqueue_head (&mdc800->irq_wait);
995 	init_waitqueue_head (&mdc800->write_wait);
996 	init_waitqueue_head (&mdc800->download_wait);
997 
998 	mdc800->irq_woken = 0;
999 	mdc800->downloaded = 0;
1000 	mdc800->written = 0;
1001 
1002 	mdc800->irq_urb_buffer=kmalloc (8, GFP_KERNEL);
1003 	if (!mdc800->irq_urb_buffer)
1004 		goto cleanup_on_fail;
1005 	mdc800->write_urb_buffer=kmalloc (8, GFP_KERNEL);
1006 	if (!mdc800->write_urb_buffer)
1007 		goto cleanup_on_fail;
1008 	mdc800->download_urb_buffer=kmalloc (64, GFP_KERNEL);
1009 	if (!mdc800->download_urb_buffer)
1010 		goto cleanup_on_fail;
1011 
1012 	mdc800->irq_urb=usb_alloc_urb (0, GFP_KERNEL);
1013 	if (!mdc800->irq_urb)
1014 		goto cleanup_on_fail;
1015 	mdc800->download_urb=usb_alloc_urb (0, GFP_KERNEL);
1016 	if (!mdc800->download_urb)
1017 		goto cleanup_on_fail;
1018 	mdc800->write_urb=usb_alloc_urb (0, GFP_KERNEL);
1019 	if (!mdc800->write_urb)
1020 		goto cleanup_on_fail;
1021 
1022 	/* Register the driver */
1023 	retval = usb_register(&mdc800_usb_driver);
1024 	if (retval)
1025 		goto cleanup_on_fail;
1026 
1027 	info (DRIVER_VERSION ":" DRIVER_DESC);
1028 
1029 	return 0;
1030 
1031 	/* Clean driver up, when something fails */
1032 
1033 cleanup_on_fail:
1034 
1035 	if (mdc800 != NULL)
1036 	{
1037 		err ("can't alloc memory!");
1038 
1039 		kfree(mdc800->download_urb_buffer);
1040 		kfree(mdc800->write_urb_buffer);
1041 		kfree(mdc800->irq_urb_buffer);
1042 
1043 		usb_free_urb(mdc800->write_urb);
1044 		usb_free_urb(mdc800->download_urb);
1045 		usb_free_urb(mdc800->irq_urb);
1046 
1047 		kfree (mdc800);
1048 	}
1049 	mdc800 = NULL;
1050 	return retval;
1051 }
1052 
1053 
1054 static void __exit usb_mdc800_cleanup (void)
1055 {
1056 	usb_deregister (&mdc800_usb_driver);
1057 
1058 	usb_free_urb (mdc800->irq_urb);
1059 	usb_free_urb (mdc800->download_urb);
1060 	usb_free_urb (mdc800->write_urb);
1061 
1062 	kfree (mdc800->irq_urb_buffer);
1063 	kfree (mdc800->write_urb_buffer);
1064 	kfree (mdc800->download_urb_buffer);
1065 
1066 	kfree (mdc800);
1067 	mdc800 = NULL;
1068 }
1069 
1070 module_init (usb_mdc800_init);
1071 module_exit (usb_mdc800_cleanup);
1072 
1073 MODULE_AUTHOR( DRIVER_AUTHOR );
1074 MODULE_DESCRIPTION( DRIVER_DESC );
1075 MODULE_LICENSE("GPL");
1076 
1077