xref: /openbmc/linux/drivers/usb/image/mdc800.c (revision f15cbe6f1a4b4d9df59142fc8e4abb973302cf44)
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 =	__constant_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 = 	__constant_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 = 	__constant_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 = 	__constant_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 	int status = urb->status;
288 
289 	if (status >= 0) {
290 
291 		//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]);
292 
293 		if (mdc800_isBusy (b))
294 		{
295 			if (!mdc800->camera_busy)
296 			{
297 				mdc800->camera_busy=1;
298 				dbg ("gets busy");
299 			}
300 		}
301 		else
302 		{
303 			if (mdc800->camera_busy && mdc800_isReady (b))
304 			{
305 				mdc800->camera_busy=0;
306 				dbg ("gets ready");
307 			}
308 		}
309 		if (!(mdc800_isBusy (b) || mdc800_isReady (b)))
310 		{
311 			/* Store Data in camera_answer field */
312 			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]);
313 
314 			memcpy (mdc800->camera_response,b,8);
315 			data_received=1;
316 		}
317 	}
318 	wake_up= ( mdc800->camera_request_ready > 0 )
319 		&&
320 		(
321 			((mdc800->camera_request_ready == 1) && (!mdc800->camera_busy))
322 		||
323 			((mdc800->camera_request_ready == 2) && data_received)
324 		||
325 			((mdc800->camera_request_ready == 3) && (mdc800->camera_busy))
326 		||
327 			(status < 0)
328 		);
329 
330 	if (wake_up)
331 	{
332 		mdc800->camera_request_ready=0;
333 		mdc800->irq_woken=1;
334 		wake_up (&mdc800->irq_wait);
335 	}
336 }
337 
338 
339 /*
340  * Waits a while until the irq responds that camera is ready
341  *
342  *  mode : 0: Wait for camera gets ready
343  *         1: Wait for receiving data
344  *         2: Wait for camera gets busy
345  *
346  * msec: Time to wait
347  */
348 static int mdc800_usb_waitForIRQ (int mode, int msec)
349 {
350 	mdc800->camera_request_ready=1+mode;
351 
352 	wait_event_timeout(mdc800->irq_wait, mdc800->irq_woken, msec*HZ/1000);
353 	mdc800->irq_woken = 0;
354 
355 	if (mdc800->camera_request_ready>0)
356 	{
357 		mdc800->camera_request_ready=0;
358 		err ("timeout waiting for camera.");
359 		return -1;
360 	}
361 
362 	if (mdc800->state == NOT_CONNECTED)
363 	{
364 		warn ("Camera gets disconnected during waiting for irq.");
365 		mdc800->camera_request_ready=0;
366 		return -2;
367 	}
368 
369 	return 0;
370 }
371 
372 
373 /*
374  * The write_urb callback function
375  */
376 static void mdc800_usb_write_notify (struct urb *urb)
377 {
378 	struct mdc800_data* mdc800=urb->context;
379 	int status = urb->status;
380 
381 	if (status != 0)
382 		err ("writing command fails (status=%i)", 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 		err ("request bytes fails (status:%i)", status);
410 	}
411 	mdc800->downloaded = 1;
412 	wake_up (&mdc800->download_wait);
413 }
414 
415 
416 /***************************************************************************
417 	Probing for the Camera
418  ***************************************************************************/
419 
420 static struct usb_driver mdc800_usb_driver;
421 static const struct file_operations mdc800_device_ops;
422 static struct usb_class_driver mdc800_class = {
423 	.name =		"mdc800%d",
424 	.fops =		&mdc800_device_ops,
425 	.minor_base =	MDC800_DEVICE_MINOR_BASE,
426 };
427 
428 
429 /*
430  * Callback to search the Mustek MDC800 on the USB Bus
431  */
432 static int mdc800_usb_probe (struct usb_interface *intf,
433 			       const struct usb_device_id *id)
434 {
435 	int i,j;
436 	struct usb_host_interface *intf_desc;
437 	struct usb_device *dev = interface_to_usbdev (intf);
438 	int irq_interval=0;
439 	int retval;
440 
441 	dbg ("(mdc800_usb_probe) called.");
442 
443 
444 	if (mdc800->dev != NULL)
445 	{
446 		warn ("only one Mustek MDC800 is supported.");
447 		return -ENODEV;
448 	}
449 
450 	if (dev->descriptor.bNumConfigurations != 1)
451 	{
452 		err ("probe fails -> wrong Number of Configuration");
453 		return -ENODEV;
454 	}
455 	intf_desc = intf->cur_altsetting;
456 
457 	if (
458 			( intf_desc->desc.bInterfaceClass != 0xff )
459 		||	( intf_desc->desc.bInterfaceSubClass != 0 )
460 		|| ( intf_desc->desc.bInterfaceProtocol != 0 )
461 		|| ( intf_desc->desc.bNumEndpoints != 4)
462 	)
463 	{
464 		err ("probe fails -> wrong Interface");
465 		return -ENODEV;
466 	}
467 
468 	/* Check the Endpoints */
469 	for (i=0; i<4; i++)
470 	{
471 		mdc800->endpoint[i]=-1;
472 		for (j=0; j<4; j++)
473 		{
474 			if (mdc800_endpoint_equals (&intf_desc->endpoint [j].desc,&mdc800_ed [i]))
475 			{
476 				mdc800->endpoint[i]=intf_desc->endpoint [j].desc.bEndpointAddress ;
477 				if (i==1)
478 				{
479 					irq_interval=intf_desc->endpoint [j].desc.bInterval;
480 				}
481 			}
482 		}
483 		if (mdc800->endpoint[i] == -1)
484 		{
485 			err ("probe fails -> Wrong Endpoints.");
486 			return -ENODEV;
487 		}
488 	}
489 
490 
491 	info ("Found Mustek MDC800 on USB.");
492 
493 	mutex_lock(&mdc800->io_lock);
494 
495 	retval = usb_register_dev(intf, &mdc800_class);
496 	if (retval) {
497 		err ("Not able to get a minor for this device.");
498 		return -ENODEV;
499 	}
500 
501 	mdc800->dev=dev;
502 	mdc800->open=0;
503 
504 	/* Setup URB Structs */
505 	usb_fill_int_urb (
506 		mdc800->irq_urb,
507 		mdc800->dev,
508 		usb_rcvintpipe (mdc800->dev,mdc800->endpoint [1]),
509 		mdc800->irq_urb_buffer,
510 		8,
511 		mdc800_usb_irq,
512 		mdc800,
513 		irq_interval
514 	);
515 
516 	usb_fill_bulk_urb (
517 		mdc800->write_urb,
518 		mdc800->dev,
519 		usb_sndbulkpipe (mdc800->dev, mdc800->endpoint[0]),
520 		mdc800->write_urb_buffer,
521 		8,
522 		mdc800_usb_write_notify,
523 		mdc800
524 	);
525 
526 	usb_fill_bulk_urb (
527 		mdc800->download_urb,
528 		mdc800->dev,
529 		usb_rcvbulkpipe (mdc800->dev, mdc800->endpoint [3]),
530 		mdc800->download_urb_buffer,
531 		64,
532 		mdc800_usb_download_notify,
533 		mdc800
534 	);
535 
536 	mdc800->state=READY;
537 
538 	mutex_unlock(&mdc800->io_lock);
539 
540 	usb_set_intfdata(intf, mdc800);
541 	return 0;
542 }
543 
544 
545 /*
546  * Disconnect USB device (maybe the MDC800)
547  */
548 static void mdc800_usb_disconnect (struct usb_interface *intf)
549 {
550 	struct mdc800_data* mdc800 = usb_get_intfdata(intf);
551 
552 	dbg ("(mdc800_usb_disconnect) called");
553 
554 	if (mdc800) {
555 		if (mdc800->state == NOT_CONNECTED)
556 			return;
557 
558 		usb_deregister_dev(intf, &mdc800_class);
559 
560 		/* must be under lock to make sure no URB
561 		   is submitted after usb_kill_urb() */
562 		mutex_lock(&mdc800->io_lock);
563 		mdc800->state=NOT_CONNECTED;
564 
565 		usb_kill_urb(mdc800->irq_urb);
566 		usb_kill_urb(mdc800->write_urb);
567 		usb_kill_urb(mdc800->download_urb);
568 		mutex_unlock(&mdc800->io_lock);
569 
570 		mdc800->dev = NULL;
571 		usb_set_intfdata(intf, NULL);
572 	}
573 	info ("Mustek MDC800 disconnected from USB.");
574 }
575 
576 
577 /***************************************************************************
578 	The Misc device Part (file_operations)
579 ****************************************************************************/
580 
581 /*
582  * This Function calc the Answersize for a command.
583  */
584 static int mdc800_getAnswerSize (char command)
585 {
586 	switch ((unsigned char) command)
587 	{
588 		case 0x2a:
589 		case 0x49:
590 		case 0x51:
591 		case 0x0d:
592 		case 0x20:
593 		case 0x07:
594 		case 0x01:
595 		case 0x25:
596 		case 0x00:
597 			return 8;
598 
599 		case 0x05:
600 		case 0x3e:
601 			return mdc800->pic_len;
602 
603 		case 0x09:
604 			return 4096;
605 
606 		default:
607 			return 0;
608 	}
609 }
610 
611 
612 /*
613  * Init the device: (1) alloc mem (2) Increase MOD Count ..
614  */
615 static int mdc800_device_open (struct inode* inode, struct file *file)
616 {
617 	int retval=0;
618 	int errn=0;
619 
620 	mutex_lock(&mdc800->io_lock);
621 
622 	if (mdc800->state == NOT_CONNECTED)
623 	{
624 		errn=-EBUSY;
625 		goto error_out;
626 	}
627 	if (mdc800->open)
628 	{
629 		errn=-EBUSY;
630 		goto error_out;
631 	}
632 
633 	mdc800->in_count=0;
634 	mdc800->out_count=0;
635 	mdc800->out_ptr=0;
636 	mdc800->pic_index=0;
637 	mdc800->pic_len=-1;
638 	mdc800->download_left=0;
639 
640 	mdc800->camera_busy=0;
641 	mdc800->camera_request_ready=0;
642 
643 	retval=0;
644 	mdc800->irq_urb->dev = mdc800->dev;
645 	retval = usb_submit_urb (mdc800->irq_urb, GFP_KERNEL);
646 	if (retval) {
647 		err ("request USB irq fails (submit_retval=%i).", retval);
648 		errn = -EIO;
649 		goto error_out;
650 	}
651 
652 	mdc800->open=1;
653 	dbg ("Mustek MDC800 device opened.");
654 
655 error_out:
656 	mutex_unlock(&mdc800->io_lock);
657 	return errn;
658 }
659 
660 
661 /*
662  * Close the Camera and release Memory
663  */
664 static int mdc800_device_release (struct inode* inode, struct file *file)
665 {
666 	int retval=0;
667 	dbg ("Mustek MDC800 device closed.");
668 
669 	mutex_lock(&mdc800->io_lock);
670 	if (mdc800->open && (mdc800->state != NOT_CONNECTED))
671 	{
672 		usb_kill_urb(mdc800->irq_urb);
673 		usb_kill_urb(mdc800->write_urb);
674 		usb_kill_urb(mdc800->download_urb);
675 		mdc800->open=0;
676 	}
677 	else
678 	{
679 		retval=-EIO;
680 	}
681 
682 	mutex_unlock(&mdc800->io_lock);
683 	return retval;
684 }
685 
686 
687 /*
688  * The Device read callback Function
689  */
690 static ssize_t mdc800_device_read (struct file *file, char __user *buf, size_t len, loff_t *pos)
691 {
692 	size_t left=len, sts=len; /* single transfer size */
693 	char __user *ptr = buf;
694 	int retval;
695 
696 	mutex_lock(&mdc800->io_lock);
697 	if (mdc800->state == NOT_CONNECTED)
698 	{
699 		mutex_unlock(&mdc800->io_lock);
700 		return -EBUSY;
701 	}
702 	if (mdc800->state == WORKING)
703 	{
704 		warn ("Illegal State \"working\" reached during read ?!");
705 		mutex_unlock(&mdc800->io_lock);
706 		return -EBUSY;
707 	}
708 	if (!mdc800->open)
709 	{
710 		mutex_unlock(&mdc800->io_lock);
711 		return -EBUSY;
712 	}
713 
714 	while (left)
715 	{
716 		if (signal_pending (current))
717 		{
718 			mutex_unlock(&mdc800->io_lock);
719 			return -EINTR;
720 		}
721 
722 		sts=left > (mdc800->out_count-mdc800->out_ptr)?mdc800->out_count-mdc800->out_ptr:left;
723 
724 		if (sts <= 0)
725 		{
726 			/* Too less Data in buffer */
727 			if (mdc800->state == DOWNLOAD)
728 			{
729 				mdc800->out_count=0;
730 				mdc800->out_ptr=0;
731 
732 				/* Download -> Request new bytes */
733 				mdc800->download_urb->dev = mdc800->dev;
734 				retval = usb_submit_urb (mdc800->download_urb, GFP_KERNEL);
735 				if (retval) {
736 					err ("Can't submit download urb (retval=%i)",retval);
737 					mutex_unlock(&mdc800->io_lock);
738 					return len-left;
739 				}
740 				wait_event_timeout(mdc800->download_wait, mdc800->downloaded,
741 										TO_DOWNLOAD_GET_READY*HZ/1000);
742 				mdc800->downloaded = 0;
743 				if (mdc800->download_urb->status != 0)
744 				{
745 					err ("request download-bytes fails (status=%i)",mdc800->download_urb->status);
746 					mutex_unlock(&mdc800->io_lock);
747 					return len-left;
748 				}
749 			}
750 			else
751 			{
752 				/* No more bytes -> that's an error*/
753 				mutex_unlock(&mdc800->io_lock);
754 				return -EIO;
755 			}
756 		}
757 		else
758 		{
759 			/* Copy Bytes */
760 			if (copy_to_user(ptr, &mdc800->out [mdc800->out_ptr],
761 						sts)) {
762 				mutex_unlock(&mdc800->io_lock);
763 				return -EFAULT;
764 			}
765 			ptr+=sts;
766 			left-=sts;
767 			mdc800->out_ptr+=sts;
768 		}
769 	}
770 
771 	mutex_unlock(&mdc800->io_lock);
772 	return len-left;
773 }
774 
775 
776 /*
777  * The Device write callback Function
778  * If a 8Byte Command is received, it will be send to the camera.
779  * After this the driver initiates the request for the answer or
780  * just waits until the camera becomes ready.
781  */
782 static ssize_t mdc800_device_write (struct file *file, const char __user *buf, size_t len, loff_t *pos)
783 {
784 	size_t i=0;
785 	int retval;
786 
787 	mutex_lock(&mdc800->io_lock);
788 	if (mdc800->state != READY)
789 	{
790 		mutex_unlock(&mdc800->io_lock);
791 		return -EBUSY;
792 	}
793 	if (!mdc800->open )
794 	{
795 		mutex_unlock(&mdc800->io_lock);
796 		return -EBUSY;
797 	}
798 
799 	while (i<len)
800 	{
801 		unsigned char c;
802 		if (signal_pending (current))
803 		{
804 			mutex_unlock(&mdc800->io_lock);
805 			return -EINTR;
806 		}
807 
808 		if(get_user(c, buf+i))
809 		{
810 			mutex_unlock(&mdc800->io_lock);
811 			return -EFAULT;
812 		}
813 
814 		/* check for command start */
815 		if (c == 0x55)
816 		{
817 			mdc800->in_count=0;
818 			mdc800->out_count=0;
819 			mdc800->out_ptr=0;
820 			mdc800->download_left=0;
821 		}
822 
823 		/* save command byte */
824 		if (mdc800->in_count < 8)
825 		{
826 			mdc800->in[mdc800->in_count] = c;
827 			mdc800->in_count++;
828 		}
829 		else
830 		{
831 			mutex_unlock(&mdc800->io_lock);
832 			return -EIO;
833 		}
834 
835 		/* Command Buffer full ? -> send it to camera */
836 		if (mdc800->in_count == 8)
837 		{
838 			int answersize;
839 
840 			if (mdc800_usb_waitForIRQ (0,TO_GET_READY))
841 			{
842 				err ("Camera didn't get ready.\n");
843 				mutex_unlock(&mdc800->io_lock);
844 				return -EIO;
845 			}
846 
847 			answersize=mdc800_getAnswerSize (mdc800->in[1]);
848 
849 			mdc800->state=WORKING;
850 			memcpy (mdc800->write_urb->transfer_buffer, mdc800->in,8);
851 			mdc800->write_urb->dev = mdc800->dev;
852 			retval = usb_submit_urb (mdc800->write_urb, GFP_KERNEL);
853 			if (retval) {
854 				err ("submitting write urb fails (retval=%i)", retval);
855 				mutex_unlock(&mdc800->io_lock);
856 				return -EIO;
857 			}
858 			wait_event_timeout(mdc800->write_wait, mdc800->written, TO_WRITE_GET_READY*HZ/1000);
859 			mdc800->written = 0;
860 			if (mdc800->state == WORKING)
861 			{
862 				usb_kill_urb(mdc800->write_urb);
863 				mutex_unlock(&mdc800->io_lock);
864 				return -EIO;
865 			}
866 
867 			switch ((unsigned char) mdc800->in[1])
868 			{
869 				case 0x05: /* Download Image */
870 				case 0x3e: /* Take shot in Fine Mode (WCam Mode) */
871 					if (mdc800->pic_len < 0)
872 					{
873 						err ("call 0x07 before 0x05,0x3e");
874 						mdc800->state=READY;
875 						mutex_unlock(&mdc800->io_lock);
876 						return -EIO;
877 					}
878 					mdc800->pic_len=-1;
879 
880 				case 0x09: /* Download Thumbnail */
881 					mdc800->download_left=answersize+64;
882 					mdc800->state=DOWNLOAD;
883 					mdc800_usb_waitForIRQ (0,TO_DOWNLOAD_GET_BUSY);
884 					break;
885 
886 
887 				default:
888 					if (answersize)
889 					{
890 
891 						if (mdc800_usb_waitForIRQ (1,TO_READ_FROM_IRQ))
892 						{
893 							err ("requesting answer from irq fails");
894 							mutex_unlock(&mdc800->io_lock);
895 							return -EIO;
896 						}
897 
898 						/* Write dummy data, (this is ugly but part of the USB Protocol */
899 						/* if you use endpoint 1 as bulk and not as irq) */
900 						memcpy (mdc800->out, mdc800->camera_response,8);
901 
902 						/* This is the interpreted answer */
903 						memcpy (&mdc800->out[8], mdc800->camera_response,8);
904 
905 						mdc800->out_ptr=0;
906 						mdc800->out_count=16;
907 
908 						/* Cache the Imagesize, if command was getImageSize */
909 						if (mdc800->in [1] == (char) 0x07)
910 						{
911 							mdc800->pic_len=(int) 65536*(unsigned char) mdc800->camera_response[0]+256*(unsigned char) mdc800->camera_response[1]+(unsigned char) mdc800->camera_response[2];
912 
913 							dbg ("cached imagesize = %i",mdc800->pic_len);
914 						}
915 
916 					}
917 					else
918 					{
919 						if (mdc800_usb_waitForIRQ (0,TO_DEFAULT_COMMAND))
920 						{
921 							err ("Command Timeout.");
922 							mutex_unlock(&mdc800->io_lock);
923 							return -EIO;
924 						}
925 					}
926 					mdc800->state=READY;
927 					break;
928 			}
929 		}
930 		i++;
931 	}
932 	mutex_unlock(&mdc800->io_lock);
933 	return i;
934 }
935 
936 
937 /***************************************************************************
938 	Init and Cleanup this driver (Structs and types)
939 ****************************************************************************/
940 
941 /* File Operations of this drivers */
942 static const struct file_operations mdc800_device_ops =
943 {
944 	.owner =	THIS_MODULE,
945 	.read =		mdc800_device_read,
946 	.write =	mdc800_device_write,
947 	.open =		mdc800_device_open,
948 	.release =	mdc800_device_release,
949 };
950 
951 
952 
953 static struct usb_device_id mdc800_table [] = {
954 	{ USB_DEVICE(MDC800_VENDOR_ID, MDC800_PRODUCT_ID) },
955 	{ }						/* Terminating entry */
956 };
957 
958 MODULE_DEVICE_TABLE (usb, mdc800_table);
959 /*
960  * USB Driver Struct for this device
961  */
962 static struct usb_driver mdc800_usb_driver =
963 {
964 	.name =		"mdc800",
965 	.probe =	mdc800_usb_probe,
966 	.disconnect =	mdc800_usb_disconnect,
967 	.id_table =	mdc800_table
968 };
969 
970 
971 
972 /************************************************************************
973 	Init and Cleanup this driver (Main Functions)
974 *************************************************************************/
975 
976 static int __init usb_mdc800_init (void)
977 {
978 	int retval = -ENODEV;
979 	/* Allocate Memory */
980 	mdc800=kzalloc (sizeof (struct mdc800_data), GFP_KERNEL);
981 	if (!mdc800)
982 		goto cleanup_on_fail;
983 
984 	mdc800->dev = NULL;
985 	mdc800->state=NOT_CONNECTED;
986 	mutex_init (&mdc800->io_lock);
987 
988 	init_waitqueue_head (&mdc800->irq_wait);
989 	init_waitqueue_head (&mdc800->write_wait);
990 	init_waitqueue_head (&mdc800->download_wait);
991 
992 	mdc800->irq_woken = 0;
993 	mdc800->downloaded = 0;
994 	mdc800->written = 0;
995 
996 	mdc800->irq_urb_buffer=kmalloc (8, GFP_KERNEL);
997 	if (!mdc800->irq_urb_buffer)
998 		goto cleanup_on_fail;
999 	mdc800->write_urb_buffer=kmalloc (8, GFP_KERNEL);
1000 	if (!mdc800->write_urb_buffer)
1001 		goto cleanup_on_fail;
1002 	mdc800->download_urb_buffer=kmalloc (64, GFP_KERNEL);
1003 	if (!mdc800->download_urb_buffer)
1004 		goto cleanup_on_fail;
1005 
1006 	mdc800->irq_urb=usb_alloc_urb (0, GFP_KERNEL);
1007 	if (!mdc800->irq_urb)
1008 		goto cleanup_on_fail;
1009 	mdc800->download_urb=usb_alloc_urb (0, GFP_KERNEL);
1010 	if (!mdc800->download_urb)
1011 		goto cleanup_on_fail;
1012 	mdc800->write_urb=usb_alloc_urb (0, GFP_KERNEL);
1013 	if (!mdc800->write_urb)
1014 		goto cleanup_on_fail;
1015 
1016 	/* Register the driver */
1017 	retval = usb_register(&mdc800_usb_driver);
1018 	if (retval)
1019 		goto cleanup_on_fail;
1020 
1021 	info (DRIVER_VERSION ":" DRIVER_DESC);
1022 
1023 	return 0;
1024 
1025 	/* Clean driver up, when something fails */
1026 
1027 cleanup_on_fail:
1028 
1029 	if (mdc800 != NULL)
1030 	{
1031 		err ("can't alloc memory!");
1032 
1033 		kfree(mdc800->download_urb_buffer);
1034 		kfree(mdc800->write_urb_buffer);
1035 		kfree(mdc800->irq_urb_buffer);
1036 
1037 		usb_free_urb(mdc800->write_urb);
1038 		usb_free_urb(mdc800->download_urb);
1039 		usb_free_urb(mdc800->irq_urb);
1040 
1041 		kfree (mdc800);
1042 	}
1043 	mdc800 = NULL;
1044 	return retval;
1045 }
1046 
1047 
1048 static void __exit usb_mdc800_cleanup (void)
1049 {
1050 	usb_deregister (&mdc800_usb_driver);
1051 
1052 	usb_free_urb (mdc800->irq_urb);
1053 	usb_free_urb (mdc800->download_urb);
1054 	usb_free_urb (mdc800->write_urb);
1055 
1056 	kfree (mdc800->irq_urb_buffer);
1057 	kfree (mdc800->write_urb_buffer);
1058 	kfree (mdc800->download_urb_buffer);
1059 
1060 	kfree (mdc800);
1061 	mdc800 = NULL;
1062 }
1063 
1064 module_init (usb_mdc800_init);
1065 module_exit (usb_mdc800_cleanup);
1066 
1067 MODULE_AUTHOR( DRIVER_AUTHOR );
1068 MODULE_DESCRIPTION( DRIVER_DESC );
1069 MODULE_LICENSE("GPL");
1070 
1071