xref: /openbmc/linux/drivers/usb/image/mdc800.c (revision 95e9fd10)
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/wait.h>
98 #include <linux/mutex.h>
99 
100 #include <linux/usb.h>
101 #include <linux/fs.h>
102 
103 /*
104  * Version Information
105  */
106 #define DRIVER_VERSION "v0.7.5 (30/10/2000)"
107 #define DRIVER_AUTHOR "Henning Zabel <henning@uni-paderborn.de>"
108 #define DRIVER_DESC "USB Driver for Mustek MDC800 Digital Camera"
109 
110 /* Vendor and Product Information */
111 #define MDC800_VENDOR_ID 	0x055f
112 #define MDC800_PRODUCT_ID	0xa800
113 
114 /* Timeouts (msec) */
115 #define TO_DOWNLOAD_GET_READY		1500
116 #define TO_DOWNLOAD_GET_BUSY		1500
117 #define TO_WRITE_GET_READY		1000
118 #define TO_DEFAULT_COMMAND		5000
119 #define TO_READ_FROM_IRQ 		TO_DEFAULT_COMMAND
120 #define TO_GET_READY			TO_DEFAULT_COMMAND
121 
122 /* Minor Number of the device (create with mknod /dev/mustek c 180 32) */
123 #define MDC800_DEVICE_MINOR_BASE 32
124 
125 
126 /**************************************************************************
127 	Data and structs
128 ***************************************************************************/
129 
130 
131 typedef enum {
132 	NOT_CONNECTED, READY, WORKING, DOWNLOAD
133 } mdc800_state;
134 
135 
136 /* Data for the driver */
137 struct mdc800_data
138 {
139 	struct usb_device *	dev;			// Device Data
140 	mdc800_state 		state;
141 
142 	unsigned int		endpoint [4];
143 
144 	struct urb *		irq_urb;
145 	wait_queue_head_t	irq_wait;
146 	int			irq_woken;
147 	char*			irq_urb_buffer;
148 
149 	int			camera_busy;          // is camera busy ?
150 	int 			camera_request_ready; // Status to synchronize with irq
151 	char 			camera_response [8];  // last Bytes send after busy
152 
153 	struct urb *   		write_urb;
154 	char*			write_urb_buffer;
155 	wait_queue_head_t	write_wait;
156 	int			written;
157 
158 
159 	struct urb *   		download_urb;
160 	char*			download_urb_buffer;
161 	wait_queue_head_t	download_wait;
162 	int			downloaded;
163 	int			download_left;		// Bytes left to download ?
164 
165 
166 	/* Device Data */
167 	char			out [64];	// Answer Buffer
168 	int 			out_ptr;	// Index to the first not readen byte
169 	int			out_count;	// Bytes in the buffer
170 
171 	int			open;		// Camera device open ?
172 	struct mutex		io_lock;	// IO -lock
173 
174 	char 			in [8];		// Command Input Buffer
175 	int  			in_count;
176 
177 	int			pic_index;	// Cache for the Imagesize (-1 for nothing cached )
178 	int			pic_len;
179 	int			minor;
180 };
181 
182 
183 /* Specification of the Endpoints */
184 static struct usb_endpoint_descriptor mdc800_ed [4] =
185 {
186 	{
187 		.bLength = 		0,
188 		.bDescriptorType =	0,
189 		.bEndpointAddress =	0x01,
190 		.bmAttributes = 	0x02,
191 		.wMaxPacketSize =	cpu_to_le16(8),
192 		.bInterval = 		0,
193 		.bRefresh = 		0,
194 		.bSynchAddress = 	0,
195 	},
196 	{
197 		.bLength = 		0,
198 		.bDescriptorType = 	0,
199 		.bEndpointAddress = 	0x82,
200 		.bmAttributes = 	0x03,
201 		.wMaxPacketSize = 	cpu_to_le16(8),
202 		.bInterval = 		0,
203 		.bRefresh = 		0,
204 		.bSynchAddress = 	0,
205 	},
206 	{
207 		.bLength = 		0,
208 		.bDescriptorType = 	0,
209 		.bEndpointAddress = 	0x03,
210 		.bmAttributes = 	0x02,
211 		.wMaxPacketSize = 	cpu_to_le16(64),
212 		.bInterval = 		0,
213 		.bRefresh = 		0,
214 		.bSynchAddress = 	0,
215 	},
216 	{
217 		.bLength = 		0,
218 		.bDescriptorType = 	0,
219 		.bEndpointAddress = 	0x84,
220 		.bmAttributes = 	0x02,
221 		.wMaxPacketSize = 	cpu_to_le16(64),
222 		.bInterval = 		0,
223 		.bRefresh = 		0,
224 		.bSynchAddress = 	0,
225 	},
226 };
227 
228 /* The Variable used by the driver */
229 static struct mdc800_data* mdc800;
230 
231 
232 /***************************************************************************
233 	The USB Part of the driver
234 ****************************************************************************/
235 
236 static int mdc800_endpoint_equals (struct usb_endpoint_descriptor *a,struct usb_endpoint_descriptor *b)
237 {
238 	return (
239 		   ( a->bEndpointAddress == b->bEndpointAddress )
240 		&& ( a->bmAttributes     == b->bmAttributes     )
241 		&& ( a->wMaxPacketSize   == b->wMaxPacketSize   )
242 	);
243 }
244 
245 
246 /*
247  * Checks whether the camera responds busy
248  */
249 static int mdc800_isBusy (char* ch)
250 {
251 	int i=0;
252 	while (i<8)
253 	{
254 		if (ch [i] != (char)0x99)
255 			return 0;
256 		i++;
257 	}
258 	return 1;
259 }
260 
261 
262 /*
263  * Checks whether the Camera is ready
264  */
265 static int mdc800_isReady (char *ch)
266 {
267 	int i=0;
268 	while (i<8)
269 	{
270 		if (ch [i] != (char)0xbb)
271 			return 0;
272 		i++;
273 	}
274 	return 1;
275 }
276 
277 
278 
279 /*
280  * USB IRQ Handler for InputLine
281  */
282 static void mdc800_usb_irq (struct urb *urb)
283 {
284 	int data_received=0, wake_up;
285 	unsigned char* b=urb->transfer_buffer;
286 	struct mdc800_data* mdc800=urb->context;
287 	struct device *dev = &mdc800->dev->dev;
288 	int status = urb->status;
289 
290 	if (status >= 0) {
291 		if (mdc800_isBusy (b))
292 		{
293 			if (!mdc800->camera_busy)
294 			{
295 				mdc800->camera_busy=1;
296 				dev_dbg(dev, "gets busy\n");
297 			}
298 		}
299 		else
300 		{
301 			if (mdc800->camera_busy && mdc800_isReady (b))
302 			{
303 				mdc800->camera_busy=0;
304 				dev_dbg(dev, "gets ready\n");
305 			}
306 		}
307 		if (!(mdc800_isBusy (b) || mdc800_isReady (b)))
308 		{
309 			/* Store Data in camera_answer field */
310 			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]);
311 
312 			memcpy (mdc800->camera_response,b,8);
313 			data_received=1;
314 		}
315 	}
316 	wake_up= ( mdc800->camera_request_ready > 0 )
317 		&&
318 		(
319 			((mdc800->camera_request_ready == 1) && (!mdc800->camera_busy))
320 		||
321 			((mdc800->camera_request_ready == 2) && data_received)
322 		||
323 			((mdc800->camera_request_ready == 3) && (mdc800->camera_busy))
324 		||
325 			(status < 0)
326 		);
327 
328 	if (wake_up)
329 	{
330 		mdc800->camera_request_ready=0;
331 		mdc800->irq_woken=1;
332 		wake_up (&mdc800->irq_wait);
333 	}
334 }
335 
336 
337 /*
338  * Waits a while until the irq responds that camera is ready
339  *
340  *  mode : 0: Wait for camera gets ready
341  *         1: Wait for receiving data
342  *         2: Wait for camera gets busy
343  *
344  * msec: Time to wait
345  */
346 static int mdc800_usb_waitForIRQ (int mode, int msec)
347 {
348 	mdc800->camera_request_ready=1+mode;
349 
350 	wait_event_timeout(mdc800->irq_wait, mdc800->irq_woken, msec*HZ/1000);
351 	mdc800->irq_woken = 0;
352 
353 	if (mdc800->camera_request_ready>0)
354 	{
355 		mdc800->camera_request_ready=0;
356 		dev_err(&mdc800->dev->dev, "timeout waiting for camera.\n");
357 		return -1;
358 	}
359 
360 	if (mdc800->state == NOT_CONNECTED)
361 	{
362 		printk(KERN_WARNING "mdc800: Camera gets disconnected "
363 		       "during waiting for irq.\n");
364 		mdc800->camera_request_ready=0;
365 		return -2;
366 	}
367 
368 	return 0;
369 }
370 
371 
372 /*
373  * The write_urb callback function
374  */
375 static void mdc800_usb_write_notify (struct urb *urb)
376 {
377 	struct mdc800_data* mdc800=urb->context;
378 	int status = urb->status;
379 
380 	if (status != 0)
381 		dev_err(&mdc800->dev->dev,
382 			"writing command fails (status=%i)\n", status);
383 	else
384 		mdc800->state=READY;
385 	mdc800->written = 1;
386 	wake_up (&mdc800->write_wait);
387 }
388 
389 
390 /*
391  * The download_urb callback function
392  */
393 static void mdc800_usb_download_notify (struct urb *urb)
394 {
395 	struct mdc800_data* mdc800=urb->context;
396 	int status = urb->status;
397 
398 	if (status == 0) {
399 		/* Fill output buffer with these data */
400 		memcpy (mdc800->out,  urb->transfer_buffer, 64);
401 		mdc800->out_count=64;
402 		mdc800->out_ptr=0;
403 		mdc800->download_left-=64;
404 		if (mdc800->download_left == 0)
405 		{
406 			mdc800->state=READY;
407 		}
408 	} else {
409 		dev_err(&mdc800->dev->dev,
410 			"request bytes fails (status:%i)\n", status);
411 	}
412 	mdc800->downloaded = 1;
413 	wake_up (&mdc800->download_wait);
414 }
415 
416 
417 /***************************************************************************
418 	Probing for the Camera
419  ***************************************************************************/
420 
421 static struct usb_driver mdc800_usb_driver;
422 static const struct file_operations mdc800_device_ops;
423 static struct usb_class_driver mdc800_class = {
424 	.name =		"mdc800%d",
425 	.fops =		&mdc800_device_ops,
426 	.minor_base =	MDC800_DEVICE_MINOR_BASE,
427 };
428 
429 
430 /*
431  * Callback to search the Mustek MDC800 on the USB Bus
432  */
433 static int mdc800_usb_probe (struct usb_interface *intf,
434 			       const struct usb_device_id *id)
435 {
436 	int i,j;
437 	struct usb_host_interface *intf_desc;
438 	struct usb_device *dev = interface_to_usbdev (intf);
439 	int irq_interval=0;
440 	int retval;
441 
442 	dev_dbg(&intf->dev, "(%s) called.\n", __func__);
443 
444 
445 	if (mdc800->dev != NULL)
446 	{
447 		dev_warn(&intf->dev, "only one Mustek MDC800 is supported.\n");
448 		return -ENODEV;
449 	}
450 
451 	if (dev->descriptor.bNumConfigurations != 1)
452 	{
453 		dev_err(&intf->dev,
454 			"probe fails -> wrong Number of Configuration\n");
455 		return -ENODEV;
456 	}
457 	intf_desc = intf->cur_altsetting;
458 
459 	if (
460 			( intf_desc->desc.bInterfaceClass != 0xff )
461 		||	( intf_desc->desc.bInterfaceSubClass != 0 )
462 		|| ( intf_desc->desc.bInterfaceProtocol != 0 )
463 		|| ( intf_desc->desc.bNumEndpoints != 4)
464 	)
465 	{
466 		dev_err(&intf->dev, "probe fails -> wrong Interface\n");
467 		return -ENODEV;
468 	}
469 
470 	/* Check the Endpoints */
471 	for (i=0; i<4; i++)
472 	{
473 		mdc800->endpoint[i]=-1;
474 		for (j=0; j<4; j++)
475 		{
476 			if (mdc800_endpoint_equals (&intf_desc->endpoint [j].desc,&mdc800_ed [i]))
477 			{
478 				mdc800->endpoint[i]=intf_desc->endpoint [j].desc.bEndpointAddress ;
479 				if (i==1)
480 				{
481 					irq_interval=intf_desc->endpoint [j].desc.bInterval;
482 				}
483 			}
484 		}
485 		if (mdc800->endpoint[i] == -1)
486 		{
487 			dev_err(&intf->dev, "probe fails -> Wrong Endpoints.\n");
488 			return -ENODEV;
489 		}
490 	}
491 
492 
493 	dev_info(&intf->dev, "Found Mustek MDC800 on USB.\n");
494 
495 	mutex_lock(&mdc800->io_lock);
496 
497 	retval = usb_register_dev(intf, &mdc800_class);
498 	if (retval) {
499 		dev_err(&intf->dev, "Not able to get a minor for this device.\n");
500 		mutex_unlock(&mdc800->io_lock);
501 		return -ENODEV;
502 	}
503 
504 	mdc800->dev=dev;
505 	mdc800->open=0;
506 
507 	/* Setup URB Structs */
508 	usb_fill_int_urb (
509 		mdc800->irq_urb,
510 		mdc800->dev,
511 		usb_rcvintpipe (mdc800->dev,mdc800->endpoint [1]),
512 		mdc800->irq_urb_buffer,
513 		8,
514 		mdc800_usb_irq,
515 		mdc800,
516 		irq_interval
517 	);
518 
519 	usb_fill_bulk_urb (
520 		mdc800->write_urb,
521 		mdc800->dev,
522 		usb_sndbulkpipe (mdc800->dev, mdc800->endpoint[0]),
523 		mdc800->write_urb_buffer,
524 		8,
525 		mdc800_usb_write_notify,
526 		mdc800
527 	);
528 
529 	usb_fill_bulk_urb (
530 		mdc800->download_urb,
531 		mdc800->dev,
532 		usb_rcvbulkpipe (mdc800->dev, mdc800->endpoint [3]),
533 		mdc800->download_urb_buffer,
534 		64,
535 		mdc800_usb_download_notify,
536 		mdc800
537 	);
538 
539 	mdc800->state=READY;
540 
541 	mutex_unlock(&mdc800->io_lock);
542 
543 	usb_set_intfdata(intf, mdc800);
544 	return 0;
545 }
546 
547 
548 /*
549  * Disconnect USB device (maybe the MDC800)
550  */
551 static void mdc800_usb_disconnect (struct usb_interface *intf)
552 {
553 	struct mdc800_data* mdc800 = usb_get_intfdata(intf);
554 
555 	dev_dbg(&intf->dev, "(%s) called\n", __func__);
556 
557 	if (mdc800) {
558 		if (mdc800->state == NOT_CONNECTED)
559 			return;
560 
561 		usb_deregister_dev(intf, &mdc800_class);
562 
563 		/* must be under lock to make sure no URB
564 		   is submitted after usb_kill_urb() */
565 		mutex_lock(&mdc800->io_lock);
566 		mdc800->state=NOT_CONNECTED;
567 
568 		usb_kill_urb(mdc800->irq_urb);
569 		usb_kill_urb(mdc800->write_urb);
570 		usb_kill_urb(mdc800->download_urb);
571 		mutex_unlock(&mdc800->io_lock);
572 
573 		mdc800->dev = NULL;
574 		usb_set_intfdata(intf, NULL);
575 	}
576 	dev_info(&intf->dev, "Mustek MDC800 disconnected from USB.\n");
577 }
578 
579 
580 /***************************************************************************
581 	The Misc device Part (file_operations)
582 ****************************************************************************/
583 
584 /*
585  * This Function calc the Answersize for a command.
586  */
587 static int mdc800_getAnswerSize (char command)
588 {
589 	switch ((unsigned char) command)
590 	{
591 		case 0x2a:
592 		case 0x49:
593 		case 0x51:
594 		case 0x0d:
595 		case 0x20:
596 		case 0x07:
597 		case 0x01:
598 		case 0x25:
599 		case 0x00:
600 			return 8;
601 
602 		case 0x05:
603 		case 0x3e:
604 			return mdc800->pic_len;
605 
606 		case 0x09:
607 			return 4096;
608 
609 		default:
610 			return 0;
611 	}
612 }
613 
614 
615 /*
616  * Init the device: (1) alloc mem (2) Increase MOD Count ..
617  */
618 static int mdc800_device_open (struct inode* inode, struct file *file)
619 {
620 	int retval=0;
621 	int errn=0;
622 
623 	mutex_lock(&mdc800->io_lock);
624 
625 	if (mdc800->state == NOT_CONNECTED)
626 	{
627 		errn=-EBUSY;
628 		goto error_out;
629 	}
630 	if (mdc800->open)
631 	{
632 		errn=-EBUSY;
633 		goto error_out;
634 	}
635 
636 	mdc800->in_count=0;
637 	mdc800->out_count=0;
638 	mdc800->out_ptr=0;
639 	mdc800->pic_index=0;
640 	mdc800->pic_len=-1;
641 	mdc800->download_left=0;
642 
643 	mdc800->camera_busy=0;
644 	mdc800->camera_request_ready=0;
645 
646 	retval=0;
647 	mdc800->irq_urb->dev = mdc800->dev;
648 	retval = usb_submit_urb (mdc800->irq_urb, GFP_KERNEL);
649 	if (retval) {
650 		dev_err(&mdc800->dev->dev,
651 			"request USB irq fails (submit_retval=%i).\n", retval);
652 		errn = -EIO;
653 		goto error_out;
654 	}
655 
656 	mdc800->open=1;
657 	dev_dbg(&mdc800->dev->dev, "Mustek MDC800 device opened.\n");
658 
659 error_out:
660 	mutex_unlock(&mdc800->io_lock);
661 	return errn;
662 }
663 
664 
665 /*
666  * Close the Camera and release Memory
667  */
668 static int mdc800_device_release (struct inode* inode, struct file *file)
669 {
670 	int retval=0;
671 
672 	mutex_lock(&mdc800->io_lock);
673 	if (mdc800->open && (mdc800->state != NOT_CONNECTED))
674 	{
675 		usb_kill_urb(mdc800->irq_urb);
676 		usb_kill_urb(mdc800->write_urb);
677 		usb_kill_urb(mdc800->download_urb);
678 		mdc800->open=0;
679 	}
680 	else
681 	{
682 		retval=-EIO;
683 	}
684 
685 	mutex_unlock(&mdc800->io_lock);
686 	return retval;
687 }
688 
689 
690 /*
691  * The Device read callback Function
692  */
693 static ssize_t mdc800_device_read (struct file *file, char __user *buf, size_t len, loff_t *pos)
694 {
695 	size_t left=len, sts=len; /* single transfer size */
696 	char __user *ptr = buf;
697 	int retval;
698 
699 	mutex_lock(&mdc800->io_lock);
700 	if (mdc800->state == NOT_CONNECTED)
701 	{
702 		mutex_unlock(&mdc800->io_lock);
703 		return -EBUSY;
704 	}
705 	if (mdc800->state == WORKING)
706 	{
707 		printk(KERN_WARNING "mdc800: Illegal State \"working\""
708 		       "reached during read ?!\n");
709 		mutex_unlock(&mdc800->io_lock);
710 		return -EBUSY;
711 	}
712 	if (!mdc800->open)
713 	{
714 		mutex_unlock(&mdc800->io_lock);
715 		return -EBUSY;
716 	}
717 
718 	while (left)
719 	{
720 		if (signal_pending (current))
721 		{
722 			mutex_unlock(&mdc800->io_lock);
723 			return -EINTR;
724 		}
725 
726 		sts=left > (mdc800->out_count-mdc800->out_ptr)?mdc800->out_count-mdc800->out_ptr:left;
727 
728 		if (sts <= 0)
729 		{
730 			/* Too less Data in buffer */
731 			if (mdc800->state == DOWNLOAD)
732 			{
733 				mdc800->out_count=0;
734 				mdc800->out_ptr=0;
735 
736 				/* Download -> Request new bytes */
737 				mdc800->download_urb->dev = mdc800->dev;
738 				retval = usb_submit_urb (mdc800->download_urb, GFP_KERNEL);
739 				if (retval) {
740 					dev_err(&mdc800->dev->dev,
741 						"Can't submit download urb "
742 						"(retval=%i)\n", retval);
743 					mutex_unlock(&mdc800->io_lock);
744 					return len-left;
745 				}
746 				wait_event_timeout(mdc800->download_wait, mdc800->downloaded,
747 										TO_DOWNLOAD_GET_READY*HZ/1000);
748 				mdc800->downloaded = 0;
749 				if (mdc800->download_urb->status != 0)
750 				{
751 					dev_err(&mdc800->dev->dev,
752 						"request download-bytes fails "
753 						"(status=%i)\n",
754 						mdc800->download_urb->status);
755 					mutex_unlock(&mdc800->io_lock);
756 					return len-left;
757 				}
758 			}
759 			else
760 			{
761 				/* No more bytes -> that's an error*/
762 				mutex_unlock(&mdc800->io_lock);
763 				return -EIO;
764 			}
765 		}
766 		else
767 		{
768 			/* Copy Bytes */
769 			if (copy_to_user(ptr, &mdc800->out [mdc800->out_ptr],
770 						sts)) {
771 				mutex_unlock(&mdc800->io_lock);
772 				return -EFAULT;
773 			}
774 			ptr+=sts;
775 			left-=sts;
776 			mdc800->out_ptr+=sts;
777 		}
778 	}
779 
780 	mutex_unlock(&mdc800->io_lock);
781 	return len-left;
782 }
783 
784 
785 /*
786  * The Device write callback Function
787  * If a 8Byte Command is received, it will be send to the camera.
788  * After this the driver initiates the request for the answer or
789  * just waits until the camera becomes ready.
790  */
791 static ssize_t mdc800_device_write (struct file *file, const char __user *buf, size_t len, loff_t *pos)
792 {
793 	size_t i=0;
794 	int retval;
795 
796 	mutex_lock(&mdc800->io_lock);
797 	if (mdc800->state != READY)
798 	{
799 		mutex_unlock(&mdc800->io_lock);
800 		return -EBUSY;
801 	}
802 	if (!mdc800->open )
803 	{
804 		mutex_unlock(&mdc800->io_lock);
805 		return -EBUSY;
806 	}
807 
808 	while (i<len)
809 	{
810 		unsigned char c;
811 		if (signal_pending (current))
812 		{
813 			mutex_unlock(&mdc800->io_lock);
814 			return -EINTR;
815 		}
816 
817 		if(get_user(c, buf+i))
818 		{
819 			mutex_unlock(&mdc800->io_lock);
820 			return -EFAULT;
821 		}
822 
823 		/* check for command start */
824 		if (c == 0x55)
825 		{
826 			mdc800->in_count=0;
827 			mdc800->out_count=0;
828 			mdc800->out_ptr=0;
829 			mdc800->download_left=0;
830 		}
831 
832 		/* save command byte */
833 		if (mdc800->in_count < 8)
834 		{
835 			mdc800->in[mdc800->in_count] = c;
836 			mdc800->in_count++;
837 		}
838 		else
839 		{
840 			mutex_unlock(&mdc800->io_lock);
841 			return -EIO;
842 		}
843 
844 		/* Command Buffer full ? -> send it to camera */
845 		if (mdc800->in_count == 8)
846 		{
847 			int answersize;
848 
849 			if (mdc800_usb_waitForIRQ (0,TO_GET_READY))
850 			{
851 				dev_err(&mdc800->dev->dev,
852 					"Camera didn't get ready.\n");
853 				mutex_unlock(&mdc800->io_lock);
854 				return -EIO;
855 			}
856 
857 			answersize=mdc800_getAnswerSize (mdc800->in[1]);
858 
859 			mdc800->state=WORKING;
860 			memcpy (mdc800->write_urb->transfer_buffer, mdc800->in,8);
861 			mdc800->write_urb->dev = mdc800->dev;
862 			retval = usb_submit_urb (mdc800->write_urb, GFP_KERNEL);
863 			if (retval) {
864 				dev_err(&mdc800->dev->dev,
865 					"submitting write urb fails "
866 					"(retval=%i)\n", retval);
867 				mutex_unlock(&mdc800->io_lock);
868 				return -EIO;
869 			}
870 			wait_event_timeout(mdc800->write_wait, mdc800->written, TO_WRITE_GET_READY*HZ/1000);
871 			mdc800->written = 0;
872 			if (mdc800->state == WORKING)
873 			{
874 				usb_kill_urb(mdc800->write_urb);
875 				mutex_unlock(&mdc800->io_lock);
876 				return -EIO;
877 			}
878 
879 			switch ((unsigned char) mdc800->in[1])
880 			{
881 				case 0x05: /* Download Image */
882 				case 0x3e: /* Take shot in Fine Mode (WCam Mode) */
883 					if (mdc800->pic_len < 0)
884 					{
885 						dev_err(&mdc800->dev->dev,
886 							"call 0x07 before "
887 							"0x05,0x3e\n");
888 						mdc800->state=READY;
889 						mutex_unlock(&mdc800->io_lock);
890 						return -EIO;
891 					}
892 					mdc800->pic_len=-1;
893 
894 				case 0x09: /* Download Thumbnail */
895 					mdc800->download_left=answersize+64;
896 					mdc800->state=DOWNLOAD;
897 					mdc800_usb_waitForIRQ (0,TO_DOWNLOAD_GET_BUSY);
898 					break;
899 
900 
901 				default:
902 					if (answersize)
903 					{
904 
905 						if (mdc800_usb_waitForIRQ (1,TO_READ_FROM_IRQ))
906 						{
907 							dev_err(&mdc800->dev->dev, "requesting answer from irq fails\n");
908 							mutex_unlock(&mdc800->io_lock);
909 							return -EIO;
910 						}
911 
912 						/* Write dummy data, (this is ugly but part of the USB Protocol */
913 						/* if you use endpoint 1 as bulk and not as irq) */
914 						memcpy (mdc800->out, mdc800->camera_response,8);
915 
916 						/* This is the interpreted answer */
917 						memcpy (&mdc800->out[8], mdc800->camera_response,8);
918 
919 						mdc800->out_ptr=0;
920 						mdc800->out_count=16;
921 
922 						/* Cache the Imagesize, if command was getImageSize */
923 						if (mdc800->in [1] == (char) 0x07)
924 						{
925 							mdc800->pic_len=(int) 65536*(unsigned char) mdc800->camera_response[0]+256*(unsigned char) mdc800->camera_response[1]+(unsigned char) mdc800->camera_response[2];
926 
927 							dev_dbg(&mdc800->dev->dev, "cached imagesize = %i\n", mdc800->pic_len);
928 						}
929 
930 					}
931 					else
932 					{
933 						if (mdc800_usb_waitForIRQ (0,TO_DEFAULT_COMMAND))
934 						{
935 							dev_err(&mdc800->dev->dev, "Command Timeout.\n");
936 							mutex_unlock(&mdc800->io_lock);
937 							return -EIO;
938 						}
939 					}
940 					mdc800->state=READY;
941 					break;
942 			}
943 		}
944 		i++;
945 	}
946 	mutex_unlock(&mdc800->io_lock);
947 	return i;
948 }
949 
950 
951 /***************************************************************************
952 	Init and Cleanup this driver (Structs and types)
953 ****************************************************************************/
954 
955 /* File Operations of this drivers */
956 static const struct file_operations mdc800_device_ops =
957 {
958 	.owner =	THIS_MODULE,
959 	.read =		mdc800_device_read,
960 	.write =	mdc800_device_write,
961 	.open =		mdc800_device_open,
962 	.release =	mdc800_device_release,
963 	.llseek =	noop_llseek,
964 };
965 
966 
967 
968 static const struct usb_device_id mdc800_table[] = {
969 	{ USB_DEVICE(MDC800_VENDOR_ID, MDC800_PRODUCT_ID) },
970 	{ }						/* Terminating entry */
971 };
972 
973 MODULE_DEVICE_TABLE (usb, mdc800_table);
974 /*
975  * USB Driver Struct for this device
976  */
977 static struct usb_driver mdc800_usb_driver =
978 {
979 	.name =		"mdc800",
980 	.probe =	mdc800_usb_probe,
981 	.disconnect =	mdc800_usb_disconnect,
982 	.id_table =	mdc800_table
983 };
984 
985 
986 
987 /************************************************************************
988 	Init and Cleanup this driver (Main Functions)
989 *************************************************************************/
990 
991 static int __init usb_mdc800_init (void)
992 {
993 	int retval = -ENODEV;
994 	/* Allocate Memory */
995 	mdc800=kzalloc (sizeof (struct mdc800_data), GFP_KERNEL);
996 	if (!mdc800)
997 		goto cleanup_on_fail;
998 
999 	mdc800->dev = NULL;
1000 	mdc800->state=NOT_CONNECTED;
1001 	mutex_init (&mdc800->io_lock);
1002 
1003 	init_waitqueue_head (&mdc800->irq_wait);
1004 	init_waitqueue_head (&mdc800->write_wait);
1005 	init_waitqueue_head (&mdc800->download_wait);
1006 
1007 	mdc800->irq_woken = 0;
1008 	mdc800->downloaded = 0;
1009 	mdc800->written = 0;
1010 
1011 	mdc800->irq_urb_buffer=kmalloc (8, GFP_KERNEL);
1012 	if (!mdc800->irq_urb_buffer)
1013 		goto cleanup_on_fail;
1014 	mdc800->write_urb_buffer=kmalloc (8, GFP_KERNEL);
1015 	if (!mdc800->write_urb_buffer)
1016 		goto cleanup_on_fail;
1017 	mdc800->download_urb_buffer=kmalloc (64, GFP_KERNEL);
1018 	if (!mdc800->download_urb_buffer)
1019 		goto cleanup_on_fail;
1020 
1021 	mdc800->irq_urb=usb_alloc_urb (0, GFP_KERNEL);
1022 	if (!mdc800->irq_urb)
1023 		goto cleanup_on_fail;
1024 	mdc800->download_urb=usb_alloc_urb (0, GFP_KERNEL);
1025 	if (!mdc800->download_urb)
1026 		goto cleanup_on_fail;
1027 	mdc800->write_urb=usb_alloc_urb (0, GFP_KERNEL);
1028 	if (!mdc800->write_urb)
1029 		goto cleanup_on_fail;
1030 
1031 	/* Register the driver */
1032 	retval = usb_register(&mdc800_usb_driver);
1033 	if (retval)
1034 		goto cleanup_on_fail;
1035 
1036 	printk(KERN_INFO KBUILD_MODNAME ": " DRIVER_VERSION ":"
1037 	       DRIVER_DESC "\n");
1038 
1039 	return 0;
1040 
1041 	/* Clean driver up, when something fails */
1042 
1043 cleanup_on_fail:
1044 
1045 	if (mdc800 != NULL)
1046 	{
1047 		printk(KERN_ERR "mdc800: can't alloc memory!\n");
1048 
1049 		kfree(mdc800->download_urb_buffer);
1050 		kfree(mdc800->write_urb_buffer);
1051 		kfree(mdc800->irq_urb_buffer);
1052 
1053 		usb_free_urb(mdc800->write_urb);
1054 		usb_free_urb(mdc800->download_urb);
1055 		usb_free_urb(mdc800->irq_urb);
1056 
1057 		kfree (mdc800);
1058 	}
1059 	mdc800 = NULL;
1060 	return retval;
1061 }
1062 
1063 
1064 static void __exit usb_mdc800_cleanup (void)
1065 {
1066 	usb_deregister (&mdc800_usb_driver);
1067 
1068 	usb_free_urb (mdc800->irq_urb);
1069 	usb_free_urb (mdc800->download_urb);
1070 	usb_free_urb (mdc800->write_urb);
1071 
1072 	kfree (mdc800->irq_urb_buffer);
1073 	kfree (mdc800->write_urb_buffer);
1074 	kfree (mdc800->download_urb_buffer);
1075 
1076 	kfree (mdc800);
1077 	mdc800 = NULL;
1078 }
1079 
1080 module_init (usb_mdc800_init);
1081 module_exit (usb_mdc800_cleanup);
1082 
1083 MODULE_AUTHOR( DRIVER_AUTHOR );
1084 MODULE_DESCRIPTION( DRIVER_DESC );
1085 MODULE_LICENSE("GPL");
1086 
1087