1/*
2 * adutux - driver for ADU devices from Ontrak Control Systems
3 * This is an experimental driver. Use at your own risk.
4 * This driver is not supported by Ontrak Control Systems.
5 *
6 * Copyright (c) 2003 John Homppi (SCO, leave this notice here)
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of
11 * the License, or (at your option) any later version.
12 *
13 * derived from the Lego USB Tower driver 0.56:
14 * Copyright (c) 2003 David Glance <davidgsf@sourceforge.net>
15 *               2001 Juergen Stuber <stuber@loria.fr>
16 * that was derived from USB Skeleton driver - 0.5
17 * Copyright (c) 2001 Greg Kroah-Hartman (greg@kroah.com)
18 *
19 */
20
21#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
22
23#include <linux/kernel.h>
24#include <linux/errno.h>
25#include <linux/slab.h>
26#include <linux/module.h>
27#include <linux/usb.h>
28#include <linux/mutex.h>
29#include <linux/uaccess.h>
30
31/* Version Information */
32#define DRIVER_VERSION "v0.0.13"
33#define DRIVER_AUTHOR "John Homppi"
34#define DRIVER_DESC "adutux (see www.ontrak.net)"
35
36/* Define these values to match your device */
37#define ADU_VENDOR_ID 0x0a07
38#define ADU_PRODUCT_ID 0x0064
39
40/* table of devices that work with this driver */
41static const struct usb_device_id device_table[] = {
42	{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID) },		/* ADU100 */
43	{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+20) },	/* ADU120 */
44	{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+30) },	/* ADU130 */
45	{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+100) },	/* ADU200 */
46	{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+108) },	/* ADU208 */
47	{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+118) },	/* ADU218 */
48	{ } /* Terminating entry */
49};
50
51MODULE_DEVICE_TABLE(usb, device_table);
52
53#ifdef CONFIG_USB_DYNAMIC_MINORS
54#define ADU_MINOR_BASE	0
55#else
56#define ADU_MINOR_BASE	67
57#endif
58
59/* we can have up to this number of device plugged in at once */
60#define MAX_DEVICES	16
61
62#define COMMAND_TIMEOUT	(2*HZ)	/* 60 second timeout for a command */
63
64/*
65 * The locking scheme is a vanilla 3-lock:
66 *   adu_device.buflock: A spinlock, covers what IRQs touch.
67 *   adutux_mutex:       A Static lock to cover open_count. It would also cover
68 *                       any globals, but we don't have them in 2.6.
69 *   adu_device.mtx:     A mutex to hold across sleepers like copy_from_user.
70 *                       It covers all of adu_device, except the open_count
71 *                       and what .buflock covers.
72 */
73
74/* Structure to hold all of our device specific stuff */
75struct adu_device {
76	struct mutex		mtx;
77	struct usb_device *udev; /* save off the usb device pointer */
78	struct usb_interface *interface;
79	unsigned int		minor; /* the starting minor number for this device */
80	char			serial_number[8];
81
82	int			open_count; /* number of times this port has been opened */
83
84	char		*read_buffer_primary;
85	int			read_buffer_length;
86	char		*read_buffer_secondary;
87	int			secondary_head;
88	int			secondary_tail;
89	spinlock_t		buflock;
90
91	wait_queue_head_t	read_wait;
92	wait_queue_head_t	write_wait;
93
94	char		*interrupt_in_buffer;
95	struct usb_endpoint_descriptor *interrupt_in_endpoint;
96	struct urb	*interrupt_in_urb;
97	int			read_urb_finished;
98
99	char		*interrupt_out_buffer;
100	struct usb_endpoint_descriptor *interrupt_out_endpoint;
101	struct urb	*interrupt_out_urb;
102	int			out_urb_finished;
103};
104
105static DEFINE_MUTEX(adutux_mutex);
106
107static struct usb_driver adu_driver;
108
109static inline void adu_debug_data(struct device *dev, const char *function,
110				  int size, const unsigned char *data)
111{
112	dev_dbg(dev, "%s - length = %d, data = %*ph\n",
113		function, size, size, data);
114}
115
116/**
117 * adu_abort_transfers
118 *      aborts transfers and frees associated data structures
119 */
120static void adu_abort_transfers(struct adu_device *dev)
121{
122	unsigned long flags;
123
124	if (dev->udev == NULL)
125		return;
126
127	/* shutdown transfer */
128
129	/* XXX Anchor these instead */
130	spin_lock_irqsave(&dev->buflock, flags);
131	if (!dev->read_urb_finished) {
132		spin_unlock_irqrestore(&dev->buflock, flags);
133		usb_kill_urb(dev->interrupt_in_urb);
134	} else
135		spin_unlock_irqrestore(&dev->buflock, flags);
136
137	spin_lock_irqsave(&dev->buflock, flags);
138	if (!dev->out_urb_finished) {
139		spin_unlock_irqrestore(&dev->buflock, flags);
140		usb_kill_urb(dev->interrupt_out_urb);
141	} else
142		spin_unlock_irqrestore(&dev->buflock, flags);
143}
144
145static void adu_delete(struct adu_device *dev)
146{
147	/* free data structures */
148	usb_free_urb(dev->interrupt_in_urb);
149	usb_free_urb(dev->interrupt_out_urb);
150	kfree(dev->read_buffer_primary);
151	kfree(dev->read_buffer_secondary);
152	kfree(dev->interrupt_in_buffer);
153	kfree(dev->interrupt_out_buffer);
154	kfree(dev);
155}
156
157static void adu_interrupt_in_callback(struct urb *urb)
158{
159	struct adu_device *dev = urb->context;
160	int status = urb->status;
161
162	adu_debug_data(&dev->udev->dev, __func__,
163		       urb->actual_length, urb->transfer_buffer);
164
165	spin_lock(&dev->buflock);
166
167	if (status != 0) {
168		if ((status != -ENOENT) && (status != -ECONNRESET) &&
169			(status != -ESHUTDOWN)) {
170			dev_dbg(&dev->udev->dev,
171				"%s : nonzero status received: %d\n",
172				__func__, status);
173		}
174		goto exit;
175	}
176
177	if (urb->actual_length > 0 && dev->interrupt_in_buffer[0] != 0x00) {
178		if (dev->read_buffer_length <
179		    (4 * usb_endpoint_maxp(dev->interrupt_in_endpoint)) -
180		     (urb->actual_length)) {
181			memcpy (dev->read_buffer_primary +
182				dev->read_buffer_length,
183				dev->interrupt_in_buffer, urb->actual_length);
184
185			dev->read_buffer_length += urb->actual_length;
186			dev_dbg(&dev->udev->dev,"%s reading  %d\n", __func__,
187				urb->actual_length);
188		} else {
189			dev_dbg(&dev->udev->dev,"%s : read_buffer overflow\n",
190				__func__);
191		}
192	}
193
194exit:
195	dev->read_urb_finished = 1;
196	spin_unlock(&dev->buflock);
197	/* always wake up so we recover from errors */
198	wake_up_interruptible(&dev->read_wait);
199}
200
201static void adu_interrupt_out_callback(struct urb *urb)
202{
203	struct adu_device *dev = urb->context;
204	int status = urb->status;
205
206	adu_debug_data(&dev->udev->dev, __func__,
207		       urb->actual_length, urb->transfer_buffer);
208
209	if (status != 0) {
210		if ((status != -ENOENT) &&
211		    (status != -ECONNRESET)) {
212			dev_dbg(&dev->udev->dev,
213				"%s :nonzero status received: %d\n", __func__,
214				status);
215		}
216		return;
217	}
218
219	spin_lock(&dev->buflock);
220	dev->out_urb_finished = 1;
221	wake_up(&dev->write_wait);
222	spin_unlock(&dev->buflock);
223}
224
225static int adu_open(struct inode *inode, struct file *file)
226{
227	struct adu_device *dev = NULL;
228	struct usb_interface *interface;
229	int subminor;
230	int retval;
231
232	subminor = iminor(inode);
233
234	retval = mutex_lock_interruptible(&adutux_mutex);
235	if (retval)
236		goto exit_no_lock;
237
238	interface = usb_find_interface(&adu_driver, subminor);
239	if (!interface) {
240		pr_err("%s - error, can't find device for minor %d\n",
241		       __func__, subminor);
242		retval = -ENODEV;
243		goto exit_no_device;
244	}
245
246	dev = usb_get_intfdata(interface);
247	if (!dev || !dev->udev) {
248		retval = -ENODEV;
249		goto exit_no_device;
250	}
251
252	/* check that nobody else is using the device */
253	if (dev->open_count) {
254		retval = -EBUSY;
255		goto exit_no_device;
256	}
257
258	++dev->open_count;
259	dev_dbg(&dev->udev->dev, "%s: open count %d\n", __func__,
260		dev->open_count);
261
262	/* save device in the file's private structure */
263	file->private_data = dev;
264
265	/* initialize in direction */
266	dev->read_buffer_length = 0;
267
268	/* fixup first read by having urb waiting for it */
269	usb_fill_int_urb(dev->interrupt_in_urb, dev->udev,
270			 usb_rcvintpipe(dev->udev,
271					dev->interrupt_in_endpoint->bEndpointAddress),
272			 dev->interrupt_in_buffer,
273			 usb_endpoint_maxp(dev->interrupt_in_endpoint),
274			 adu_interrupt_in_callback, dev,
275			 dev->interrupt_in_endpoint->bInterval);
276	dev->read_urb_finished = 0;
277	if (usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL))
278		dev->read_urb_finished = 1;
279	/* we ignore failure */
280	/* end of fixup for first read */
281
282	/* initialize out direction */
283	dev->out_urb_finished = 1;
284
285	retval = 0;
286
287exit_no_device:
288	mutex_unlock(&adutux_mutex);
289exit_no_lock:
290	return retval;
291}
292
293static void adu_release_internal(struct adu_device *dev)
294{
295	/* decrement our usage count for the device */
296	--dev->open_count;
297	dev_dbg(&dev->udev->dev, "%s : open count %d\n", __func__,
298		dev->open_count);
299	if (dev->open_count <= 0) {
300		adu_abort_transfers(dev);
301		dev->open_count = 0;
302	}
303}
304
305static int adu_release(struct inode *inode, struct file *file)
306{
307	struct adu_device *dev;
308	int retval = 0;
309
310	if (file == NULL) {
311		retval = -ENODEV;
312		goto exit;
313	}
314
315	dev = file->private_data;
316	if (dev == NULL) {
317		retval = -ENODEV;
318		goto exit;
319	}
320
321	mutex_lock(&adutux_mutex); /* not interruptible */
322
323	if (dev->open_count <= 0) {
324		dev_dbg(&dev->udev->dev, "%s : device not opened\n", __func__);
325		retval = -ENODEV;
326		goto unlock;
327	}
328
329	adu_release_internal(dev);
330	if (dev->udev == NULL) {
331		/* the device was unplugged before the file was released */
332		if (!dev->open_count)	/* ... and we're the last user */
333			adu_delete(dev);
334	}
335unlock:
336	mutex_unlock(&adutux_mutex);
337exit:
338	return retval;
339}
340
341static ssize_t adu_read(struct file *file, __user char *buffer, size_t count,
342			loff_t *ppos)
343{
344	struct adu_device *dev;
345	size_t bytes_read = 0;
346	size_t bytes_to_read = count;
347	int i;
348	int retval = 0;
349	int timeout = 0;
350	int should_submit = 0;
351	unsigned long flags;
352	DECLARE_WAITQUEUE(wait, current);
353
354	dev = file->private_data;
355	if (mutex_lock_interruptible(&dev->mtx))
356		return -ERESTARTSYS;
357
358	/* verify that the device wasn't unplugged */
359	if (dev->udev == NULL) {
360		retval = -ENODEV;
361		pr_err("No device or device unplugged %d\n", retval);
362		goto exit;
363	}
364
365	/* verify that some data was requested */
366	if (count == 0) {
367		dev_dbg(&dev->udev->dev, "%s : read request of 0 bytes\n",
368			__func__);
369		goto exit;
370	}
371
372	timeout = COMMAND_TIMEOUT;
373	dev_dbg(&dev->udev->dev, "%s : about to start looping\n", __func__);
374	while (bytes_to_read) {
375		int data_in_secondary = dev->secondary_tail - dev->secondary_head;
376		dev_dbg(&dev->udev->dev,
377			"%s : while, data_in_secondary=%d, status=%d\n",
378			__func__, data_in_secondary,
379			dev->interrupt_in_urb->status);
380
381		if (data_in_secondary) {
382			/* drain secondary buffer */
383			int amount = bytes_to_read < data_in_secondary ? bytes_to_read : data_in_secondary;
384			i = copy_to_user(buffer, dev->read_buffer_secondary+dev->secondary_head, amount);
385			if (i) {
386				retval = -EFAULT;
387				goto exit;
388			}
389			dev->secondary_head += (amount - i);
390			bytes_read += (amount - i);
391			bytes_to_read -= (amount - i);
392			if (i) {
393				retval = bytes_read ? bytes_read : -EFAULT;
394				goto exit;
395			}
396		} else {
397			/* we check the primary buffer */
398			spin_lock_irqsave (&dev->buflock, flags);
399			if (dev->read_buffer_length) {
400				/* we secure access to the primary */
401				char *tmp;
402				dev_dbg(&dev->udev->dev,
403					"%s : swap, read_buffer_length = %d\n",
404					__func__, dev->read_buffer_length);
405				tmp = dev->read_buffer_secondary;
406				dev->read_buffer_secondary = dev->read_buffer_primary;
407				dev->read_buffer_primary = tmp;
408				dev->secondary_head = 0;
409				dev->secondary_tail = dev->read_buffer_length;
410				dev->read_buffer_length = 0;
411				spin_unlock_irqrestore(&dev->buflock, flags);
412				/* we have a free buffer so use it */
413				should_submit = 1;
414			} else {
415				/* even the primary was empty - we may need to do IO */
416				if (!dev->read_urb_finished) {
417					/* somebody is doing IO */
418					spin_unlock_irqrestore(&dev->buflock, flags);
419					dev_dbg(&dev->udev->dev,
420						"%s : submitted already\n",
421						__func__);
422				} else {
423					/* we must initiate input */
424					dev_dbg(&dev->udev->dev,
425						"%s : initiate input\n",
426						__func__);
427					dev->read_urb_finished = 0;
428					spin_unlock_irqrestore(&dev->buflock, flags);
429
430					usb_fill_int_urb(dev->interrupt_in_urb, dev->udev,
431							usb_rcvintpipe(dev->udev,
432								dev->interrupt_in_endpoint->bEndpointAddress),
433							 dev->interrupt_in_buffer,
434							 usb_endpoint_maxp(dev->interrupt_in_endpoint),
435							 adu_interrupt_in_callback,
436							 dev,
437							 dev->interrupt_in_endpoint->bInterval);
438					retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
439					if (retval) {
440						dev->read_urb_finished = 1;
441						if (retval == -ENOMEM) {
442							retval = bytes_read ? bytes_read : -ENOMEM;
443						}
444						dev_dbg(&dev->udev->dev,
445							"%s : submit failed\n",
446							__func__);
447						goto exit;
448					}
449				}
450
451				/* we wait for I/O to complete */
452				set_current_state(TASK_INTERRUPTIBLE);
453				add_wait_queue(&dev->read_wait, &wait);
454				spin_lock_irqsave(&dev->buflock, flags);
455				if (!dev->read_urb_finished) {
456					spin_unlock_irqrestore(&dev->buflock, flags);
457					timeout = schedule_timeout(COMMAND_TIMEOUT);
458				} else {
459					spin_unlock_irqrestore(&dev->buflock, flags);
460					set_current_state(TASK_RUNNING);
461				}
462				remove_wait_queue(&dev->read_wait, &wait);
463
464				if (timeout <= 0) {
465					dev_dbg(&dev->udev->dev,
466						"%s : timeout\n", __func__);
467					retval = bytes_read ? bytes_read : -ETIMEDOUT;
468					goto exit;
469				}
470
471				if (signal_pending(current)) {
472					dev_dbg(&dev->udev->dev,
473						"%s : signal pending\n",
474						__func__);
475					retval = bytes_read ? bytes_read : -EINTR;
476					goto exit;
477				}
478			}
479		}
480	}
481
482	retval = bytes_read;
483	/* if the primary buffer is empty then use it */
484	spin_lock_irqsave(&dev->buflock, flags);
485	if (should_submit && dev->read_urb_finished) {
486		dev->read_urb_finished = 0;
487		spin_unlock_irqrestore(&dev->buflock, flags);
488		usb_fill_int_urb(dev->interrupt_in_urb, dev->udev,
489				 usb_rcvintpipe(dev->udev,
490					dev->interrupt_in_endpoint->bEndpointAddress),
491				dev->interrupt_in_buffer,
492				usb_endpoint_maxp(dev->interrupt_in_endpoint),
493				adu_interrupt_in_callback,
494				dev,
495				dev->interrupt_in_endpoint->bInterval);
496		if (usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL) != 0)
497			dev->read_urb_finished = 1;
498		/* we ignore failure */
499	} else {
500		spin_unlock_irqrestore(&dev->buflock, flags);
501	}
502
503exit:
504	/* unlock the device */
505	mutex_unlock(&dev->mtx);
506
507	return retval;
508}
509
510static ssize_t adu_write(struct file *file, const __user char *buffer,
511			 size_t count, loff_t *ppos)
512{
513	DECLARE_WAITQUEUE(waita, current);
514	struct adu_device *dev;
515	size_t bytes_written = 0;
516	size_t bytes_to_write;
517	size_t buffer_size;
518	unsigned long flags;
519	int retval;
520
521	dev = file->private_data;
522
523	retval = mutex_lock_interruptible(&dev->mtx);
524	if (retval)
525		goto exit_nolock;
526
527	/* verify that the device wasn't unplugged */
528	if (dev->udev == NULL) {
529		retval = -ENODEV;
530		pr_err("No device or device unplugged %d\n", retval);
531		goto exit;
532	}
533
534	/* verify that we actually have some data to write */
535	if (count == 0) {
536		dev_dbg(&dev->udev->dev, "%s : write request of 0 bytes\n",
537			__func__);
538		goto exit;
539	}
540
541	while (count > 0) {
542		add_wait_queue(&dev->write_wait, &waita);
543		set_current_state(TASK_INTERRUPTIBLE);
544		spin_lock_irqsave(&dev->buflock, flags);
545		if (!dev->out_urb_finished) {
546			spin_unlock_irqrestore(&dev->buflock, flags);
547
548			mutex_unlock(&dev->mtx);
549			if (signal_pending(current)) {
550				dev_dbg(&dev->udev->dev, "%s : interrupted\n",
551					__func__);
552				set_current_state(TASK_RUNNING);
553				retval = -EINTR;
554				goto exit_onqueue;
555			}
556			if (schedule_timeout(COMMAND_TIMEOUT) == 0) {
557				dev_dbg(&dev->udev->dev,
558					"%s - command timed out.\n", __func__);
559				retval = -ETIMEDOUT;
560				goto exit_onqueue;
561			}
562			remove_wait_queue(&dev->write_wait, &waita);
563			retval = mutex_lock_interruptible(&dev->mtx);
564			if (retval) {
565				retval = bytes_written ? bytes_written : retval;
566				goto exit_nolock;
567			}
568
569			dev_dbg(&dev->udev->dev,
570				"%s : in progress, count = %Zd\n",
571				__func__, count);
572		} else {
573			spin_unlock_irqrestore(&dev->buflock, flags);
574			set_current_state(TASK_RUNNING);
575			remove_wait_queue(&dev->write_wait, &waita);
576			dev_dbg(&dev->udev->dev, "%s : sending, count = %Zd\n",
577				__func__, count);
578
579			/* write the data into interrupt_out_buffer from userspace */
580			buffer_size = usb_endpoint_maxp(dev->interrupt_out_endpoint);
581			bytes_to_write = count > buffer_size ? buffer_size : count;
582			dev_dbg(&dev->udev->dev,
583				"%s : buffer_size = %Zd, count = %Zd, bytes_to_write = %Zd\n",
584				__func__, buffer_size, count, bytes_to_write);
585
586			if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write) != 0) {
587				retval = -EFAULT;
588				goto exit;
589			}
590
591			/* send off the urb */
592			usb_fill_int_urb(
593				dev->interrupt_out_urb,
594				dev->udev,
595				usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
596				dev->interrupt_out_buffer,
597				bytes_to_write,
598				adu_interrupt_out_callback,
599				dev,
600				dev->interrupt_out_endpoint->bInterval);
601			dev->interrupt_out_urb->actual_length = bytes_to_write;
602			dev->out_urb_finished = 0;
603			retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
604			if (retval < 0) {
605				dev->out_urb_finished = 1;
606				dev_err(&dev->udev->dev, "Couldn't submit "
607					"interrupt_out_urb %d\n", retval);
608				goto exit;
609			}
610
611			buffer += bytes_to_write;
612			count -= bytes_to_write;
613
614			bytes_written += bytes_to_write;
615		}
616	}
617	mutex_unlock(&dev->mtx);
618	return bytes_written;
619
620exit:
621	mutex_unlock(&dev->mtx);
622exit_nolock:
623	return retval;
624
625exit_onqueue:
626	remove_wait_queue(&dev->write_wait, &waita);
627	return retval;
628}
629
630/* file operations needed when we register this driver */
631static const struct file_operations adu_fops = {
632	.owner = THIS_MODULE,
633	.read  = adu_read,
634	.write = adu_write,
635	.open = adu_open,
636	.release = adu_release,
637	.llseek = noop_llseek,
638};
639
640/*
641 * usb class driver info in order to get a minor number from the usb core,
642 * and to have the device registered with devfs and the driver core
643 */
644static struct usb_class_driver adu_class = {
645	.name = "usb/adutux%d",
646	.fops = &adu_fops,
647	.minor_base = ADU_MINOR_BASE,
648};
649
650/**
651 * adu_probe
652 *
653 * Called by the usb core when a new device is connected that it thinks
654 * this driver might be interested in.
655 */
656static int adu_probe(struct usb_interface *interface,
657		     const struct usb_device_id *id)
658{
659	struct usb_device *udev = interface_to_usbdev(interface);
660	struct adu_device *dev = NULL;
661	struct usb_host_interface *iface_desc;
662	struct usb_endpoint_descriptor *endpoint;
663	int retval = -ENODEV;
664	int in_end_size;
665	int out_end_size;
666	int i;
667
668	if (udev == NULL) {
669		dev_err(&interface->dev, "udev is NULL.\n");
670		goto exit;
671	}
672
673	/* allocate memory for our device state and initialize it */
674	dev = kzalloc(sizeof(struct adu_device), GFP_KERNEL);
675	if (dev == NULL) {
676		dev_err(&interface->dev, "Out of memory\n");
677		retval = -ENOMEM;
678		goto exit;
679	}
680
681	mutex_init(&dev->mtx);
682	spin_lock_init(&dev->buflock);
683	dev->udev = udev;
684	init_waitqueue_head(&dev->read_wait);
685	init_waitqueue_head(&dev->write_wait);
686
687	iface_desc = &interface->altsetting[0];
688
689	/* set up the endpoint information */
690	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
691		endpoint = &iface_desc->endpoint[i].desc;
692
693		if (usb_endpoint_is_int_in(endpoint))
694			dev->interrupt_in_endpoint = endpoint;
695
696		if (usb_endpoint_is_int_out(endpoint))
697			dev->interrupt_out_endpoint = endpoint;
698	}
699	if (dev->interrupt_in_endpoint == NULL) {
700		dev_err(&interface->dev, "interrupt in endpoint not found\n");
701		goto error;
702	}
703	if (dev->interrupt_out_endpoint == NULL) {
704		dev_err(&interface->dev, "interrupt out endpoint not found\n");
705		goto error;
706	}
707
708	in_end_size = usb_endpoint_maxp(dev->interrupt_in_endpoint);
709	out_end_size = usb_endpoint_maxp(dev->interrupt_out_endpoint);
710
711	dev->read_buffer_primary = kmalloc((4 * in_end_size), GFP_KERNEL);
712	if (!dev->read_buffer_primary) {
713		dev_err(&interface->dev, "Couldn't allocate read_buffer_primary\n");
714		retval = -ENOMEM;
715		goto error;
716	}
717
718	/* debug code prime the buffer */
719	memset(dev->read_buffer_primary, 'a', in_end_size);
720	memset(dev->read_buffer_primary + in_end_size, 'b', in_end_size);
721	memset(dev->read_buffer_primary + (2 * in_end_size), 'c', in_end_size);
722	memset(dev->read_buffer_primary + (3 * in_end_size), 'd', in_end_size);
723
724	dev->read_buffer_secondary = kmalloc((4 * in_end_size), GFP_KERNEL);
725	if (!dev->read_buffer_secondary) {
726		dev_err(&interface->dev, "Couldn't allocate read_buffer_secondary\n");
727		retval = -ENOMEM;
728		goto error;
729	}
730
731	/* debug code prime the buffer */
732	memset(dev->read_buffer_secondary, 'e', in_end_size);
733	memset(dev->read_buffer_secondary + in_end_size, 'f', in_end_size);
734	memset(dev->read_buffer_secondary + (2 * in_end_size), 'g', in_end_size);
735	memset(dev->read_buffer_secondary + (3 * in_end_size), 'h', in_end_size);
736
737	dev->interrupt_in_buffer = kmalloc(in_end_size, GFP_KERNEL);
738	if (!dev->interrupt_in_buffer) {
739		dev_err(&interface->dev, "Couldn't allocate interrupt_in_buffer\n");
740		goto error;
741	}
742
743	/* debug code prime the buffer */
744	memset(dev->interrupt_in_buffer, 'i', in_end_size);
745
746	dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
747	if (!dev->interrupt_in_urb) {
748		dev_err(&interface->dev, "Couldn't allocate interrupt_in_urb\n");
749		goto error;
750	}
751	dev->interrupt_out_buffer = kmalloc(out_end_size, GFP_KERNEL);
752	if (!dev->interrupt_out_buffer) {
753		dev_err(&interface->dev, "Couldn't allocate interrupt_out_buffer\n");
754		goto error;
755	}
756	dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
757	if (!dev->interrupt_out_urb) {
758		dev_err(&interface->dev, "Couldn't allocate interrupt_out_urb\n");
759		goto error;
760	}
761
762	if (!usb_string(udev, udev->descriptor.iSerialNumber, dev->serial_number,
763			sizeof(dev->serial_number))) {
764		dev_err(&interface->dev, "Could not retrieve serial number\n");
765		goto error;
766	}
767	dev_dbg(&interface->dev,"serial_number=%s", dev->serial_number);
768
769	/* we can register the device now, as it is ready */
770	usb_set_intfdata(interface, dev);
771
772	retval = usb_register_dev(interface, &adu_class);
773
774	if (retval) {
775		/* something prevented us from registering this driver */
776		dev_err(&interface->dev, "Not able to get a minor for this device.\n");
777		usb_set_intfdata(interface, NULL);
778		goto error;
779	}
780
781	dev->minor = interface->minor;
782
783	/* let the user know what node this device is now attached to */
784	dev_info(&interface->dev, "ADU%d %s now attached to /dev/usb/adutux%d\n",
785		 le16_to_cpu(udev->descriptor.idProduct), dev->serial_number,
786		 (dev->minor - ADU_MINOR_BASE));
787exit:
788	return retval;
789
790error:
791	adu_delete(dev);
792	return retval;
793}
794
795/**
796 * adu_disconnect
797 *
798 * Called by the usb core when the device is removed from the system.
799 */
800static void adu_disconnect(struct usb_interface *interface)
801{
802	struct adu_device *dev;
803	int minor;
804
805	dev = usb_get_intfdata(interface);
806
807	mutex_lock(&dev->mtx);	/* not interruptible */
808	dev->udev = NULL;	/* poison */
809	minor = dev->minor;
810	usb_deregister_dev(interface, &adu_class);
811	mutex_unlock(&dev->mtx);
812
813	mutex_lock(&adutux_mutex);
814	usb_set_intfdata(interface, NULL);
815
816	/* if the device is not opened, then we clean up right now */
817	if (!dev->open_count)
818		adu_delete(dev);
819
820	mutex_unlock(&adutux_mutex);
821}
822
823/* usb specific object needed to register this driver with the usb subsystem */
824static struct usb_driver adu_driver = {
825	.name = "adutux",
826	.probe = adu_probe,
827	.disconnect = adu_disconnect,
828	.id_table = device_table,
829};
830
831module_usb_driver(adu_driver);
832
833MODULE_AUTHOR(DRIVER_AUTHOR);
834MODULE_DESCRIPTION(DRIVER_DESC);
835MODULE_LICENSE("GPL");
836