adutux.c revision 1865a9c382ede507065cf1575308b53495814c7d
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#include <linux/kernel.h>
22#include <linux/errno.h>
23#include <linux/init.h>
24#include <linux/slab.h>
25#include <linux/module.h>
26#include <linux/usb.h>
27#include <linux/mutex.h>
28#include <asm/uaccess.h>
29
30#ifdef CONFIG_USB_DEBUG
31static int debug = 5;
32#else
33static int debug = 1;
34#endif
35
36/* Use our own dbg macro */
37#undef dbg
38#define dbg(lvl, format, arg...) 					\
39do { 									\
40	if (debug >= lvl)						\
41		printk(KERN_DEBUG "%s: " format "\n", __FILE__, ##arg);	\
42} while (0)
43
44
45/* Version Information */
46#define DRIVER_VERSION "v0.0.13"
47#define DRIVER_AUTHOR "John Homppi"
48#define DRIVER_DESC "adutux (see www.ontrak.net)"
49
50/* Module parameters */
51module_param(debug, int, S_IRUGO | S_IWUSR);
52MODULE_PARM_DESC(debug, "Debug enabled or not");
53
54/* Define these values to match your device */
55#define ADU_VENDOR_ID 0x0a07
56#define ADU_PRODUCT_ID 0x0064
57
58/* table of devices that work with this driver */
59static const struct usb_device_id device_table[] = {
60	{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID) },		/* ADU100 */
61	{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+20) }, 	/* ADU120 */
62	{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+30) }, 	/* ADU130 */
63	{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+100) },	/* ADU200 */
64	{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+108) },	/* ADU208 */
65	{ USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+118) },	/* ADU218 */
66	{ }/* Terminating entry */
67};
68
69MODULE_DEVICE_TABLE(usb, device_table);
70
71#ifdef CONFIG_USB_DYNAMIC_MINORS
72#define ADU_MINOR_BASE	0
73#else
74#define ADU_MINOR_BASE	67
75#endif
76
77/* we can have up to this number of device plugged in at once */
78#define MAX_DEVICES	16
79
80#define COMMAND_TIMEOUT	(2*HZ)	/* 60 second timeout for a command */
81
82/*
83 * The locking scheme is a vanilla 3-lock:
84 *   adu_device.buflock: A spinlock, covers what IRQs touch.
85 *   adutux_mutex:       A Static lock to cover open_count. It would also cover
86 *                       any globals, but we don't have them in 2.6.
87 *   adu_device.mtx:     A mutex to hold across sleepers like copy_from_user.
88 *                       It covers all of adu_device, except the open_count
89 *                       and what .buflock covers.
90 */
91
92/* Structure to hold all of our device specific stuff */
93struct adu_device {
94	struct mutex		mtx;
95	struct usb_device*	udev; /* save off the usb device pointer */
96	struct usb_interface*	interface;
97	unsigned int		minor; /* the starting minor number for this device */
98	char			serial_number[8];
99
100	int			open_count; /* number of times this port has been opened */
101
102	char*			read_buffer_primary;
103	int			read_buffer_length;
104	char*			read_buffer_secondary;
105	int			secondary_head;
106	int			secondary_tail;
107	spinlock_t		buflock;
108
109	wait_queue_head_t	read_wait;
110	wait_queue_head_t	write_wait;
111
112	char*			interrupt_in_buffer;
113	struct usb_endpoint_descriptor* interrupt_in_endpoint;
114	struct urb*		interrupt_in_urb;
115	int			read_urb_finished;
116
117	char*			interrupt_out_buffer;
118	struct usb_endpoint_descriptor* interrupt_out_endpoint;
119	struct urb*		interrupt_out_urb;
120	int			out_urb_finished;
121};
122
123static DEFINE_MUTEX(adutux_mutex);
124
125static struct usb_driver adu_driver;
126
127static void adu_debug_data(int level, const char *function, int size,
128			   const unsigned char *data)
129{
130	int i;
131
132	if (debug < level)
133		return;
134
135	printk(KERN_DEBUG "%s: %s - length = %d, data = ",
136	       __FILE__, function, size);
137	for (i = 0; i < size; ++i)
138		printk("%.2x ", data[i]);
139	printk("\n");
140}
141
142/**
143 * adu_abort_transfers
144 *      aborts transfers and frees associated data structures
145 */
146static void adu_abort_transfers(struct adu_device *dev)
147{
148	unsigned long flags;
149
150	dbg(2," %s : enter", __func__);
151
152	if (dev->udev == NULL) {
153		dbg(1," %s : udev is null", __func__);
154		goto exit;
155	}
156
157	/* shutdown transfer */
158
159	/* XXX Anchor these instead */
160	spin_lock_irqsave(&dev->buflock, flags);
161	if (!dev->read_urb_finished) {
162		spin_unlock_irqrestore(&dev->buflock, flags);
163		usb_kill_urb(dev->interrupt_in_urb);
164	} else
165		spin_unlock_irqrestore(&dev->buflock, flags);
166
167	spin_lock_irqsave(&dev->buflock, flags);
168	if (!dev->out_urb_finished) {
169		spin_unlock_irqrestore(&dev->buflock, flags);
170		usb_kill_urb(dev->interrupt_out_urb);
171	} else
172		spin_unlock_irqrestore(&dev->buflock, flags);
173
174exit:
175	dbg(2," %s : leave", __func__);
176}
177
178static void adu_delete(struct adu_device *dev)
179{
180	dbg(2, "%s enter", __func__);
181
182	/* free data structures */
183	usb_free_urb(dev->interrupt_in_urb);
184	usb_free_urb(dev->interrupt_out_urb);
185	kfree(dev->read_buffer_primary);
186	kfree(dev->read_buffer_secondary);
187	kfree(dev->interrupt_in_buffer);
188	kfree(dev->interrupt_out_buffer);
189	kfree(dev);
190
191	dbg(2, "%s : leave", __func__);
192}
193
194static void adu_interrupt_in_callback(struct urb *urb)
195{
196	struct adu_device *dev = urb->context;
197	int status = urb->status;
198
199	dbg(4," %s : enter, status %d", __func__, status);
200	adu_debug_data(5, __func__, urb->actual_length,
201		       urb->transfer_buffer);
202
203	spin_lock(&dev->buflock);
204
205	if (status != 0) {
206		if ((status != -ENOENT) && (status != -ECONNRESET) &&
207			(status != -ESHUTDOWN)) {
208			dbg(1," %s : nonzero status received: %d",
209			    __func__, status);
210		}
211		goto exit;
212	}
213
214	if (urb->actual_length > 0 && dev->interrupt_in_buffer[0] != 0x00) {
215		if (dev->read_buffer_length <
216		    (4 * le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize)) -
217		     (urb->actual_length)) {
218			memcpy (dev->read_buffer_primary +
219				dev->read_buffer_length,
220				dev->interrupt_in_buffer, urb->actual_length);
221
222			dev->read_buffer_length += urb->actual_length;
223			dbg(2," %s reading  %d ", __func__,
224			    urb->actual_length);
225		} else {
226			dbg(1," %s : read_buffer overflow", __func__);
227		}
228	}
229
230exit:
231	dev->read_urb_finished = 1;
232	spin_unlock(&dev->buflock);
233	/* always wake up so we recover from errors */
234	wake_up_interruptible(&dev->read_wait);
235	adu_debug_data(5, __func__, urb->actual_length,
236		       urb->transfer_buffer);
237	dbg(4," %s : leave, status %d", __func__, status);
238}
239
240static void adu_interrupt_out_callback(struct urb *urb)
241{
242	struct adu_device *dev = urb->context;
243	int status = urb->status;
244
245	dbg(4," %s : enter, status %d", __func__, status);
246	adu_debug_data(5,__func__, urb->actual_length, urb->transfer_buffer);
247
248	if (status != 0) {
249		if ((status != -ENOENT) &&
250		    (status != -ECONNRESET)) {
251			dbg(1, " %s :nonzero status received: %d",
252			    __func__, status);
253		}
254		goto exit;
255	}
256
257	spin_lock(&dev->buflock);
258	dev->out_urb_finished = 1;
259	wake_up(&dev->write_wait);
260	spin_unlock(&dev->buflock);
261exit:
262
263	adu_debug_data(5, __func__, urb->actual_length,
264		       urb->transfer_buffer);
265	dbg(4," %s : leave, status %d", __func__, status);
266}
267
268static int adu_open(struct inode *inode, struct file *file)
269{
270	struct adu_device *dev = NULL;
271	struct usb_interface *interface;
272	int subminor;
273	int retval;
274
275	dbg(2,"%s : enter", __func__);
276
277	subminor = iminor(inode);
278
279	if ((retval = mutex_lock_interruptible(&adutux_mutex))) {
280		dbg(2, "%s : mutex lock failed", __func__);
281		goto exit_no_lock;
282	}
283
284	interface = usb_find_interface(&adu_driver, subminor);
285	if (!interface) {
286		printk(KERN_ERR "adutux: %s - error, can't find device for "
287		       "minor %d\n", __func__, subminor);
288		retval = -ENODEV;
289		goto exit_no_device;
290	}
291
292	dev = usb_get_intfdata(interface);
293	if (!dev || !dev->udev) {
294		retval = -ENODEV;
295		goto exit_no_device;
296	}
297
298	/* check that nobody else is using the device */
299	if (dev->open_count) {
300		retval = -EBUSY;
301		goto exit_no_device;
302	}
303
304	++dev->open_count;
305	dbg(2,"%s : open count %d", __func__, dev->open_count);
306
307	/* save device in the file's private structure */
308	file->private_data = dev;
309
310	/* initialize in direction */
311	dev->read_buffer_length = 0;
312
313	/* fixup first read by having urb waiting for it */
314	usb_fill_int_urb(dev->interrupt_in_urb,dev->udev,
315			 usb_rcvintpipe(dev->udev,
316					dev->interrupt_in_endpoint->bEndpointAddress),
317			 dev->interrupt_in_buffer,
318			 le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
319			 adu_interrupt_in_callback, dev,
320			 dev->interrupt_in_endpoint->bInterval);
321	dev->read_urb_finished = 0;
322	if (usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL))
323		dev->read_urb_finished = 1;
324	/* we ignore failure */
325	/* end of fixup for first read */
326
327	/* initialize out direction */
328	dev->out_urb_finished = 1;
329
330	retval = 0;
331
332exit_no_device:
333	mutex_unlock(&adutux_mutex);
334exit_no_lock:
335	dbg(2,"%s : leave, return value %d ", __func__, retval);
336	return retval;
337}
338
339static void adu_release_internal(struct adu_device *dev)
340{
341	dbg(2," %s : enter", __func__);
342
343	/* decrement our usage count for the device */
344	--dev->open_count;
345	dbg(2," %s : open count %d", __func__, dev->open_count);
346	if (dev->open_count <= 0) {
347		adu_abort_transfers(dev);
348		dev->open_count = 0;
349	}
350
351	dbg(2," %s : leave", __func__);
352}
353
354static int adu_release(struct inode *inode, struct file *file)
355{
356	struct adu_device *dev;
357	int retval = 0;
358
359	dbg(2," %s : enter", __func__);
360
361	if (file == NULL) {
362 		dbg(1," %s : file is NULL", __func__);
363		retval = -ENODEV;
364		goto exit;
365	}
366
367	dev = file->private_data;
368	if (dev == NULL) {
369 		dbg(1," %s : object is NULL", __func__);
370		retval = -ENODEV;
371		goto exit;
372	}
373
374	mutex_lock(&adutux_mutex); /* not interruptible */
375
376	if (dev->open_count <= 0) {
377		dbg(1," %s : device not opened", __func__);
378		retval = -ENODEV;
379		goto unlock;
380	}
381
382	adu_release_internal(dev);
383	if (dev->udev == NULL) {
384		/* the device was unplugged before the file was released */
385		if (!dev->open_count)	/* ... and we're the last user */
386			adu_delete(dev);
387	}
388unlock:
389	mutex_unlock(&adutux_mutex);
390exit:
391	dbg(2," %s : leave, return value %d", __func__, retval);
392	return retval;
393}
394
395static ssize_t adu_read(struct file *file, __user char *buffer, size_t count,
396			loff_t *ppos)
397{
398	struct adu_device *dev;
399	size_t bytes_read = 0;
400	size_t bytes_to_read = count;
401	int i;
402	int retval = 0;
403	int timeout = 0;
404	int should_submit = 0;
405	unsigned long flags;
406	DECLARE_WAITQUEUE(wait, current);
407
408	dbg(2," %s : enter, count = %Zd, file=%p", __func__, count, file);
409
410	dev = file->private_data;
411	dbg(2," %s : dev=%p", __func__, dev);
412
413	if (mutex_lock_interruptible(&dev->mtx))
414		return -ERESTARTSYS;
415
416	/* verify that the device wasn't unplugged */
417	if (dev->udev == NULL) {
418		retval = -ENODEV;
419		printk(KERN_ERR "adutux: No device or device unplugged %d\n",
420		       retval);
421		goto exit;
422	}
423
424	/* verify that some data was requested */
425	if (count == 0) {
426		dbg(1," %s : read request of 0 bytes", __func__);
427		goto exit;
428	}
429
430	timeout = COMMAND_TIMEOUT;
431	dbg(2," %s : about to start looping", __func__);
432	while (bytes_to_read) {
433		int data_in_secondary = dev->secondary_tail - dev->secondary_head;
434		dbg(2," %s : while, data_in_secondary=%d, status=%d",
435		    __func__, data_in_secondary,
436		    dev->interrupt_in_urb->status);
437
438		if (data_in_secondary) {
439			/* drain secondary buffer */
440			int amount = bytes_to_read < data_in_secondary ? bytes_to_read : data_in_secondary;
441			i = copy_to_user(buffer, dev->read_buffer_secondary+dev->secondary_head, amount);
442			if (i) {
443				retval = -EFAULT;
444				goto exit;
445			}
446			dev->secondary_head += (amount - i);
447			bytes_read += (amount - i);
448			bytes_to_read -= (amount - i);
449			if (i) {
450				retval = bytes_read ? bytes_read : -EFAULT;
451				goto exit;
452			}
453		} else {
454			/* we check the primary buffer */
455			spin_lock_irqsave (&dev->buflock, flags);
456			if (dev->read_buffer_length) {
457				/* we secure access to the primary */
458				char *tmp;
459				dbg(2," %s : swap, read_buffer_length = %d",
460				    __func__, dev->read_buffer_length);
461				tmp = dev->read_buffer_secondary;
462				dev->read_buffer_secondary = dev->read_buffer_primary;
463				dev->read_buffer_primary = tmp;
464				dev->secondary_head = 0;
465				dev->secondary_tail = dev->read_buffer_length;
466				dev->read_buffer_length = 0;
467				spin_unlock_irqrestore(&dev->buflock, flags);
468				/* we have a free buffer so use it */
469				should_submit = 1;
470			} else {
471				/* even the primary was empty - we may need to do IO */
472				if (!dev->read_urb_finished) {
473					/* somebody is doing IO */
474					spin_unlock_irqrestore(&dev->buflock, flags);
475					dbg(2," %s : submitted already", __func__);
476				} else {
477					/* we must initiate input */
478					dbg(2," %s : initiate input", __func__);
479					dev->read_urb_finished = 0;
480					spin_unlock_irqrestore(&dev->buflock, flags);
481
482					usb_fill_int_urb(dev->interrupt_in_urb,dev->udev,
483							 usb_rcvintpipe(dev->udev,
484							 		dev->interrupt_in_endpoint->bEndpointAddress),
485							 dev->interrupt_in_buffer,
486							 le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
487							 adu_interrupt_in_callback,
488							 dev,
489							 dev->interrupt_in_endpoint->bInterval);
490					retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
491					if (retval) {
492						dev->read_urb_finished = 1;
493						if (retval == -ENOMEM) {
494							retval = bytes_read ? bytes_read : -ENOMEM;
495						}
496						dbg(2," %s : submit failed", __func__);
497						goto exit;
498					}
499				}
500
501				/* we wait for I/O to complete */
502				set_current_state(TASK_INTERRUPTIBLE);
503				add_wait_queue(&dev->read_wait, &wait);
504				spin_lock_irqsave(&dev->buflock, flags);
505				if (!dev->read_urb_finished) {
506					spin_unlock_irqrestore(&dev->buflock, flags);
507					timeout = schedule_timeout(COMMAND_TIMEOUT);
508				} else {
509					spin_unlock_irqrestore(&dev->buflock, flags);
510					set_current_state(TASK_RUNNING);
511				}
512				remove_wait_queue(&dev->read_wait, &wait);
513
514				if (timeout <= 0) {
515					dbg(2," %s : timeout", __func__);
516					retval = bytes_read ? bytes_read : -ETIMEDOUT;
517					goto exit;
518				}
519
520				if (signal_pending(current)) {
521					dbg(2," %s : signal pending", __func__);
522					retval = bytes_read ? bytes_read : -EINTR;
523					goto exit;
524				}
525			}
526		}
527	}
528
529	retval = bytes_read;
530	/* if the primary buffer is empty then use it */
531	spin_lock_irqsave(&dev->buflock, flags);
532	if (should_submit && dev->read_urb_finished) {
533		dev->read_urb_finished = 0;
534		spin_unlock_irqrestore(&dev->buflock, flags);
535		usb_fill_int_urb(dev->interrupt_in_urb,dev->udev,
536				 usb_rcvintpipe(dev->udev,
537				 		dev->interrupt_in_endpoint->bEndpointAddress),
538				dev->interrupt_in_buffer,
539				le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
540				adu_interrupt_in_callback,
541				dev,
542				dev->interrupt_in_endpoint->bInterval);
543		if (usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL) != 0)
544			dev->read_urb_finished = 1;
545		/* we ignore failure */
546	} else {
547		spin_unlock_irqrestore(&dev->buflock, flags);
548	}
549
550exit:
551	/* unlock the device */
552	mutex_unlock(&dev->mtx);
553
554	dbg(2," %s : leave, return value %d", __func__, retval);
555	return retval;
556}
557
558static ssize_t adu_write(struct file *file, const __user char *buffer,
559			 size_t count, loff_t *ppos)
560{
561	DECLARE_WAITQUEUE(waita, current);
562	struct adu_device *dev;
563	size_t bytes_written = 0;
564	size_t bytes_to_write;
565	size_t buffer_size;
566	unsigned long flags;
567	int retval;
568
569	dbg(2," %s : enter, count = %Zd", __func__, count);
570
571	dev = file->private_data;
572
573	retval = mutex_lock_interruptible(&dev->mtx);
574	if (retval)
575		goto exit_nolock;
576
577	/* verify that the device wasn't unplugged */
578	if (dev->udev == NULL) {
579		retval = -ENODEV;
580		printk(KERN_ERR "adutux: No device or device unplugged %d\n",
581		       retval);
582		goto exit;
583	}
584
585	/* verify that we actually have some data to write */
586	if (count == 0) {
587		dbg(1," %s : write request of 0 bytes", __func__);
588		goto exit;
589	}
590
591	while (count > 0) {
592		add_wait_queue(&dev->write_wait, &waita);
593		set_current_state(TASK_INTERRUPTIBLE);
594		spin_lock_irqsave(&dev->buflock, flags);
595		if (!dev->out_urb_finished) {
596			spin_unlock_irqrestore(&dev->buflock, flags);
597
598			mutex_unlock(&dev->mtx);
599			if (signal_pending(current)) {
600				dbg(1," %s : interrupted", __func__);
601				set_current_state(TASK_RUNNING);
602				retval = -EINTR;
603				goto exit_onqueue;
604			}
605			if (schedule_timeout(COMMAND_TIMEOUT) == 0) {
606				dbg(1, "%s - command timed out.", __func__);
607				retval = -ETIMEDOUT;
608				goto exit_onqueue;
609			}
610			remove_wait_queue(&dev->write_wait, &waita);
611			retval = mutex_lock_interruptible(&dev->mtx);
612			if (retval) {
613				retval = bytes_written ? bytes_written : retval;
614				goto exit_nolock;
615			}
616
617			dbg(4," %s : in progress, count = %Zd", __func__, count);
618		} else {
619			spin_unlock_irqrestore(&dev->buflock, flags);
620			set_current_state(TASK_RUNNING);
621			remove_wait_queue(&dev->write_wait, &waita);
622			dbg(4," %s : sending, count = %Zd", __func__, count);
623
624			/* write the data into interrupt_out_buffer from userspace */
625			buffer_size = le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize);
626			bytes_to_write = count > buffer_size ? buffer_size : count;
627			dbg(4," %s : buffer_size = %Zd, count = %Zd, bytes_to_write = %Zd",
628			    __func__, buffer_size, count, bytes_to_write);
629
630			if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write) != 0) {
631				retval = -EFAULT;
632				goto exit;
633			}
634
635			/* send off the urb */
636			usb_fill_int_urb(
637				dev->interrupt_out_urb,
638				dev->udev,
639				usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
640				dev->interrupt_out_buffer,
641				bytes_to_write,
642				adu_interrupt_out_callback,
643				dev,
644				dev->interrupt_out_endpoint->bInterval);
645			dev->interrupt_out_urb->actual_length = bytes_to_write;
646			dev->out_urb_finished = 0;
647			retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
648			if (retval < 0) {
649				dev->out_urb_finished = 1;
650				dev_err(&dev->udev->dev, "Couldn't submit "
651					"interrupt_out_urb %d\n", retval);
652				goto exit;
653			}
654
655			buffer += bytes_to_write;
656			count -= bytes_to_write;
657
658			bytes_written += bytes_to_write;
659		}
660	}
661	mutex_unlock(&dev->mtx);
662	return bytes_written;
663
664exit:
665	mutex_unlock(&dev->mtx);
666exit_nolock:
667	dbg(2," %s : leave, return value %d", __func__, retval);
668	return retval;
669
670exit_onqueue:
671	remove_wait_queue(&dev->write_wait, &waita);
672	return retval;
673}
674
675/* file operations needed when we register this driver */
676static const struct file_operations adu_fops = {
677	.owner = THIS_MODULE,
678	.read  = adu_read,
679	.write = adu_write,
680	.open = adu_open,
681	.release = adu_release,
682};
683
684/*
685 * usb class driver info in order to get a minor number from the usb core,
686 * and to have the device registered with devfs and the driver core
687 */
688static struct usb_class_driver adu_class = {
689	.name = "usb/adutux%d",
690	.fops = &adu_fops,
691	.minor_base = ADU_MINOR_BASE,
692};
693
694/**
695 * adu_probe
696 *
697 * Called by the usb core when a new device is connected that it thinks
698 * this driver might be interested in.
699 */
700static int adu_probe(struct usb_interface *interface,
701		     const struct usb_device_id *id)
702{
703	struct usb_device *udev = interface_to_usbdev(interface);
704	struct adu_device *dev = NULL;
705	struct usb_host_interface *iface_desc;
706	struct usb_endpoint_descriptor *endpoint;
707	int retval = -ENODEV;
708	int in_end_size;
709	int out_end_size;
710	int i;
711
712	dbg(2," %s : enter", __func__);
713
714	if (udev == NULL) {
715		dev_err(&interface->dev, "udev is NULL.\n");
716		goto exit;
717	}
718
719	/* allocate memory for our device state and intialize it */
720	dev = kzalloc(sizeof(struct adu_device), GFP_KERNEL);
721	if (dev == NULL) {
722		dev_err(&interface->dev, "Out of memory\n");
723		retval = -ENOMEM;
724		goto exit;
725	}
726
727	mutex_init(&dev->mtx);
728	spin_lock_init(&dev->buflock);
729	dev->udev = udev;
730	init_waitqueue_head(&dev->read_wait);
731	init_waitqueue_head(&dev->write_wait);
732
733	iface_desc = &interface->altsetting[0];
734
735	/* set up the endpoint information */
736	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
737		endpoint = &iface_desc->endpoint[i].desc;
738
739		if (usb_endpoint_is_int_in(endpoint))
740			dev->interrupt_in_endpoint = endpoint;
741
742		if (usb_endpoint_is_int_out(endpoint))
743			dev->interrupt_out_endpoint = endpoint;
744	}
745	if (dev->interrupt_in_endpoint == NULL) {
746		dev_err(&interface->dev, "interrupt in endpoint not found\n");
747		goto error;
748	}
749	if (dev->interrupt_out_endpoint == NULL) {
750		dev_err(&interface->dev, "interrupt out endpoint not found\n");
751		goto error;
752	}
753
754	in_end_size = le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
755	out_end_size = le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize);
756
757	dev->read_buffer_primary = kmalloc((4 * in_end_size), GFP_KERNEL);
758	if (!dev->read_buffer_primary) {
759		dev_err(&interface->dev, "Couldn't allocate read_buffer_primary\n");
760		retval = -ENOMEM;
761		goto error;
762	}
763
764	/* debug code prime the buffer */
765	memset(dev->read_buffer_primary, 'a', in_end_size);
766	memset(dev->read_buffer_primary + in_end_size, 'b', in_end_size);
767	memset(dev->read_buffer_primary + (2 * in_end_size), 'c', in_end_size);
768	memset(dev->read_buffer_primary + (3 * in_end_size), 'd', in_end_size);
769
770	dev->read_buffer_secondary = kmalloc((4 * in_end_size), GFP_KERNEL);
771	if (!dev->read_buffer_secondary) {
772		dev_err(&interface->dev, "Couldn't allocate read_buffer_secondary\n");
773		retval = -ENOMEM;
774		goto error;
775	}
776
777	/* debug code prime the buffer */
778	memset(dev->read_buffer_secondary, 'e', in_end_size);
779	memset(dev->read_buffer_secondary + in_end_size, 'f', in_end_size);
780	memset(dev->read_buffer_secondary + (2 * in_end_size), 'g', in_end_size);
781	memset(dev->read_buffer_secondary + (3 * in_end_size), 'h', in_end_size);
782
783	dev->interrupt_in_buffer = kmalloc(in_end_size, GFP_KERNEL);
784	if (!dev->interrupt_in_buffer) {
785		dev_err(&interface->dev, "Couldn't allocate interrupt_in_buffer\n");
786		goto error;
787	}
788
789	/* debug code prime the buffer */
790	memset(dev->interrupt_in_buffer, 'i', in_end_size);
791
792	dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
793	if (!dev->interrupt_in_urb) {
794		dev_err(&interface->dev, "Couldn't allocate interrupt_in_urb\n");
795		goto error;
796	}
797	dev->interrupt_out_buffer = kmalloc(out_end_size, GFP_KERNEL);
798	if (!dev->interrupt_out_buffer) {
799		dev_err(&interface->dev, "Couldn't allocate interrupt_out_buffer\n");
800		goto error;
801	}
802	dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
803	if (!dev->interrupt_out_urb) {
804		dev_err(&interface->dev, "Couldn't allocate interrupt_out_urb\n");
805		goto error;
806	}
807
808	if (!usb_string(udev, udev->descriptor.iSerialNumber, dev->serial_number,
809			sizeof(dev->serial_number))) {
810		dev_err(&interface->dev, "Could not retrieve serial number\n");
811		goto error;
812	}
813	dbg(2," %s : serial_number=%s", __func__, dev->serial_number);
814
815	/* we can register the device now, as it is ready */
816	usb_set_intfdata(interface, dev);
817
818	retval = usb_register_dev(interface, &adu_class);
819
820	if (retval) {
821		/* something prevented us from registering this driver */
822		dev_err(&interface->dev, "Not able to get a minor for this device.\n");
823		usb_set_intfdata(interface, NULL);
824		goto error;
825	}
826
827	dev->minor = interface->minor;
828
829	/* let the user know what node this device is now attached to */
830	dev_info(&interface->dev, "ADU%d %s now attached to /dev/usb/adutux%d\n",
831		 udev->descriptor.idProduct, dev->serial_number,
832		 (dev->minor - ADU_MINOR_BASE));
833exit:
834	dbg(2," %s : leave, return value %p (dev)", __func__, dev);
835
836	return retval;
837
838error:
839	adu_delete(dev);
840	return retval;
841}
842
843/**
844 * adu_disconnect
845 *
846 * Called by the usb core when the device is removed from the system.
847 */
848static void adu_disconnect(struct usb_interface *interface)
849{
850	struct adu_device *dev;
851	int minor;
852
853	dbg(2," %s : enter", __func__);
854
855	dev = usb_get_intfdata(interface);
856
857	mutex_lock(&dev->mtx);	/* not interruptible */
858	dev->udev = NULL;	/* poison */
859	minor = dev->minor;
860	usb_deregister_dev(interface, &adu_class);
861	mutex_unlock(&dev->mtx);
862
863	mutex_lock(&adutux_mutex);
864	usb_set_intfdata(interface, NULL);
865
866	/* if the device is not opened, then we clean up right now */
867	dbg(2," %s : open count %d", __func__, dev->open_count);
868	if (!dev->open_count)
869		adu_delete(dev);
870
871	mutex_unlock(&adutux_mutex);
872
873	dev_info(&interface->dev, "ADU device adutux%d now disconnected\n",
874		 (minor - ADU_MINOR_BASE));
875
876	dbg(2," %s : leave", __func__);
877}
878
879/* usb specific object needed to register this driver with the usb subsystem */
880static struct usb_driver adu_driver = {
881	.name = "adutux",
882	.probe = adu_probe,
883	.disconnect = adu_disconnect,
884	.id_table = device_table,
885};
886
887static int __init adu_init(void)
888{
889	int result;
890
891	dbg(2," %s : enter", __func__);
892
893	/* register this driver with the USB subsystem */
894	result = usb_register(&adu_driver);
895	if (result < 0) {
896		printk(KERN_ERR "usb_register failed for the "__FILE__
897		       " driver. Error number %d\n", result);
898		goto exit;
899	}
900
901	printk(KERN_INFO "adutux " DRIVER_DESC " " DRIVER_VERSION "\n");
902	printk(KERN_INFO "adutux is an experimental driver. "
903	       "Use at your own risk\n");
904
905exit:
906	dbg(2," %s : leave, return value %d", __func__, result);
907
908	return result;
909}
910
911static void __exit adu_exit(void)
912{
913	dbg(2," %s : enter", __func__);
914	/* deregister this driver with the USB subsystem */
915	usb_deregister(&adu_driver);
916	dbg(2," %s : leave", __func__);
917}
918
919module_init(adu_init);
920module_exit(adu_exit);
921
922MODULE_AUTHOR(DRIVER_AUTHOR);
923MODULE_DESCRIPTION(DRIVER_DESC);
924MODULE_LICENSE("GPL");
925