1/*
2 * Frontier Designs Alphatrack driver
3 *
4 * Copyright (C) 2007 Michael Taht (m@taht.net)
5 *
6 * Based on the usbled driver and ldusb drivers by
7 *
8 * Copyright (C) 2004 Greg Kroah-Hartman (greg@kroah.com)
9 * Copyright (C) 2005 Michael Hund <mhund@ld-didactic.de>
10 *
11 * The ldusb driver was, in turn, derived from Lego USB Tower driver
12 * Copyright (C) 2003 David Glance <advidgsf@sourceforge.net>
13 *		 2001-2004 Juergen Stuber <starblue@users.sourceforge.net>
14 *
15 *	This program is free software; you can redistribute it and/or
16 *	modify it under the terms of the GNU General Public License as
17 *	published by the Free Software Foundation, version 2.
18 *
19 */
20
21/**
22 * This driver uses a ring buffer for time critical reading of
23 * interrupt in reports and provides read and write methods for
24 * raw interrupt reports.
25 */
26
27/* Note: this currently uses a dumb ringbuffer for reads and writes.
28 * A more optimal driver would cache and kill off outstanding urbs that are
29 * now invalid, and ignore ones that already were in the queue but valid
30 * as we only have 30 commands for the alphatrack. In particular this is
31 * key for getting lights to flash in time as otherwise many commands
32 * can be buffered up before the light change makes it to the interface.
33*/
34
35#include <linux/kernel.h>
36#include <linux/errno.h>
37#include <linux/init.h>
38#include <linux/slab.h>
39#include <linux/module.h>
40#include <linux/kobject.h>
41#include <linux/mutex.h>
42
43#include <linux/uaccess.h>
44#include <linux/input.h>
45#include <linux/usb.h>
46#include <linux/poll.h>
47
48#include "alphatrack.h"
49
50#define VENDOR_ID	0x165b
51#define PRODUCT_ID	0xfad1
52
53#ifdef CONFIG_USB_DYNAMIC_MINORS
54#define USB_ALPHATRACK_MINOR_BASE	0
55#else
56/* FIXME 176 - is another driver's minor - apply for that */
57#define USB_ALPHATRACK_MINOR_BASE	176
58#endif
59
60/* table of devices that work with this driver */
61static const struct usb_device_id usb_alphatrack_table[] = {
62	{USB_DEVICE(VENDOR_ID, PRODUCT_ID)},
63	{}			/* Terminating entry */
64};
65
66MODULE_DEVICE_TABLE(usb, usb_alphatrack_table);
67MODULE_VERSION("0.41");
68MODULE_AUTHOR("Mike Taht <m@taht.net>");
69MODULE_DESCRIPTION("Alphatrack USB Driver");
70MODULE_LICENSE("GPL");
71MODULE_SUPPORTED_DEVICE("Frontier Designs Alphatrack Control Surface");
72
73/* These aren't done yet */
74
75#define SUPPRESS_EXTRA_ONLINE_EVENTS 0
76#define BUFFERED_WRITES 0
77#define SUPPRESS_EXTRA_OFFLINE_EVENTS 0
78#define COMPRESS_FADER_EVENTS 0
79
80#define BUFFERED_READS 1
81#define RING_BUFFER_SIZE 512
82#define WRITE_BUFFER_SIZE 34
83#define ALPHATRACK_USB_TIMEOUT 10
84#define OUTPUT_CMD_SIZE 8
85#define INPUT_CMD_SIZE 12
86#define ALPHATRACK_DEBUG 0
87
88static int debug = ALPHATRACK_DEBUG;
89
90/* Use our own dbg macro */
91#define dbg_info(dev, format, arg...) do \
92	{ if (debug) dev_info(dev , format , ## arg); } while (0)
93
94#define alphatrack_ocmd_info(dev, cmd, format, arg...)
95
96#define alphatrack_icmd_info(dev, cmd, format, arg...)
97
98/* Module parameters */
99
100module_param(debug, int, S_IRUGO | S_IWUSR);
101MODULE_PARM_DESC(debug, "Debug enabled or not");
102
103/* All interrupt in transfers are collected in a ring buffer to
104 * avoid racing conditions and get better performance of the driver.
105 */
106
107static int ring_buffer_size = RING_BUFFER_SIZE;
108
109module_param(ring_buffer_size, int, S_IRUGO);
110MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size");
111
112/* The write_buffer can one day contain more than one interrupt out transfer.
113 */
114
115static int write_buffer_size = WRITE_BUFFER_SIZE;
116module_param(write_buffer_size, int, S_IRUGO);
117MODULE_PARM_DESC(write_buffer_size, "Write buffer size");
118
119/*
120 * Increase the interval for debugging purposes.
121 * or set to 1 to use the standard interval from the endpoint descriptors.
122 */
123
124static int min_interrupt_in_interval = ALPHATRACK_USB_TIMEOUT;
125module_param(min_interrupt_in_interval, int, 0);
126MODULE_PARM_DESC(min_interrupt_in_interval,
127		 "Minimum interrupt in interval in ms");
128
129static int min_interrupt_out_interval = ALPHATRACK_USB_TIMEOUT;
130module_param(min_interrupt_out_interval, int, 0);
131MODULE_PARM_DESC(min_interrupt_out_interval,
132		 "Minimum interrupt out interval in ms");
133
134/* Structure to hold all of our device specific stuff */
135
136struct usb_alphatrack {
137	struct mutex mtx;	/* locks this structure */
138	struct usb_interface *intf;	/* save off the usb interface pointer */
139	int open_count;		/* number of times this port has been opened */
140
141	/* make gcc happy */
142	struct alphatrack_icmd (*ring_buffer)[RING_BUFFER_SIZE];
143	struct alphatrack_ocmd (*write_buffer)[WRITE_BUFFER_SIZE];
144	unsigned int ring_head;
145	unsigned int ring_tail;
146
147	wait_queue_head_t read_wait;
148	wait_queue_head_t write_wait;
149
150	unsigned char *interrupt_in_buffer;
151	unsigned char *oldi_buffer;
152	struct usb_endpoint_descriptor *interrupt_in_endpoint;
153	struct urb *interrupt_in_urb;
154	int interrupt_in_interval;
155	size_t interrupt_in_endpoint_size;
156	int interrupt_in_running;
157	int interrupt_in_done;
158
159	char *interrupt_out_buffer;
160	struct usb_endpoint_descriptor *interrupt_out_endpoint;
161	struct urb *interrupt_out_urb;
162	int interrupt_out_interval;
163	size_t interrupt_out_endpoint_size;
164	int interrupt_out_busy;
165
166	atomic_t writes_pending;
167	int event;		/* alternate interface to events */
168	int fader;		/* 10 bits */
169	int lights;		/* 23 bits */
170	unsigned char dump_state;	/* 0 if disabled 1 if enabled */
171	unsigned char enable;	/* 0 if disabled 1 if enabled */
172	unsigned char offline;	/* if the device is out of range or asleep */
173	unsigned char verbose;	/* be verbose in error reporting */
174	unsigned char last_cmd[OUTPUT_CMD_SIZE];
175	unsigned char screen[32];
176};
177
178/* prevent races between open() and disconnect() */
179static DEFINE_MUTEX(disconnect_mutex);
180
181/* forward declaration */
182
183static struct usb_driver usb_alphatrack_driver;
184
185/**
186 *	usb_alphatrack_abort_transfers
187 *      aborts transfers and frees associated data structures
188 */
189static void usb_alphatrack_abort_transfers(struct usb_alphatrack *dev)
190{
191	/* shutdown transfer */
192	if (dev->interrupt_in_running) {
193		dev->interrupt_in_running = 0;
194		if (dev->intf)
195			usb_kill_urb(dev->interrupt_in_urb);
196	}
197	if (dev->interrupt_out_busy)
198		if (dev->intf)
199			usb_kill_urb(dev->interrupt_out_urb);
200}
201
202/**
203 *	usb_alphatrack_delete
204 */
205static void usb_alphatrack_delete(struct usb_alphatrack *dev)
206{
207	usb_alphatrack_abort_transfers(dev);
208	usb_free_urb(dev->interrupt_in_urb);
209	usb_free_urb(dev->interrupt_out_urb);
210	kfree(dev->ring_buffer);
211	kfree(dev->interrupt_in_buffer);
212	kfree(dev->interrupt_out_buffer);
213	kfree(dev);		/* fixme oldi_buffer */
214}
215
216/**
217 *	usb_alphatrack_interrupt_in_callback
218 */
219
220static void usb_alphatrack_interrupt_in_callback(struct urb *urb)
221{
222	struct usb_alphatrack *dev = urb->context;
223	unsigned int next_ring_head;
224	int retval = -1;
225
226	if (urb->status) {
227		if (urb->status == -ENOENT ||
228		    urb->status == -ECONNRESET || urb->status == -ESHUTDOWN) {
229			goto exit;
230		} else {
231			dbg_info(&dev->intf->dev,
232				 "%s: nonzero status received: %d\n", __func__,
233				 urb->status);
234			goto resubmit;	/* maybe we can recover */
235		}
236	}
237
238	if (urb->actual_length != INPUT_CMD_SIZE) {
239		dev_warn(&dev->intf->dev,
240			 "Urb length was %d bytes!!"
241			 "Do something intelligent\n", urb->actual_length);
242	} else {
243		alphatrack_ocmd_info(&dev->intf->dev,
244				     &(*dev->ring_buffer)[dev->ring_tail].cmd,
245				     "%s", "bla");
246		if (memcmp
247		    (dev->interrupt_in_buffer, dev->oldi_buffer,
248		     INPUT_CMD_SIZE) == 0) {
249			goto resubmit;
250		}
251		memcpy(dev->oldi_buffer, dev->interrupt_in_buffer,
252		       INPUT_CMD_SIZE);
253
254#if SUPPRESS_EXTRA_OFFLINE_EVENTS
255		if (dev->offline == 2 && dev->interrupt_in_buffer[1] == 0xff)
256			goto resubmit;
257		if (dev->offline == 1 && dev->interrupt_in_buffer[1] == 0xff) {
258			dev->offline = 2;
259			goto resubmit;
260		}
261/* Always pass one offline event up the stack */
262		if (dev->offline > 0 && dev->interrupt_in_buffer[1] != 0xff)
263			dev->offline = 0;
264		if (dev->offline == 0 && dev->interrupt_in_buffer[1] == 0xff)
265			dev->offline = 1;
266#endif
267		dbg_info(&dev->intf->dev, "%s: head, tail are %x, %x\n",
268			 __func__, dev->ring_head, dev->ring_tail);
269		next_ring_head = (dev->ring_head + 1) % ring_buffer_size;
270
271		if (next_ring_head != dev->ring_tail) {
272			memcpy(&((*dev->ring_buffer)[dev->ring_head]),
273			       dev->interrupt_in_buffer, urb->actual_length);
274			dev->ring_head = next_ring_head;
275			retval = 0;
276			memset(dev->interrupt_in_buffer, 0, urb->actual_length);
277		} else {
278			dev_warn(&dev->intf->dev,
279				 "Ring buffer overflow, %d bytes dropped\n",
280				 urb->actual_length);
281			memset(dev->interrupt_in_buffer, 0, urb->actual_length);
282		}
283	}
284
285resubmit:
286	/* resubmit if we're still running */
287	if (dev->interrupt_in_running && dev->intf) {
288		retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
289		if (retval)
290			dev_err(&dev->intf->dev,
291				"usb_submit_urb failed (%d)\n", retval);
292	}
293
294exit:
295	dev->interrupt_in_done = 1;
296	wake_up_interruptible(&dev->read_wait);
297}
298
299/**
300 *	usb_alphatrack_interrupt_out_callback
301 */
302static void usb_alphatrack_interrupt_out_callback(struct urb *urb)
303{
304	struct usb_alphatrack *dev = urb->context;
305
306	/* sync/async unlink faults aren't errors */
307	if (urb->status && !(urb->status == -ENOENT ||
308			     urb->status == -ECONNRESET ||
309			     urb->status == -ESHUTDOWN))
310		dbg_info(&dev->intf->dev,
311			 "%s - nonzero write interrupt status received: %d\n",
312			 __func__, urb->status);
313	atomic_dec(&dev->writes_pending);
314	dev->interrupt_out_busy = 0;
315	wake_up_interruptible(&dev->write_wait);
316}
317
318/**
319 *	usb_alphatrack_open
320 */
321static int usb_alphatrack_open(struct inode *inode, struct file *file)
322{
323	struct usb_alphatrack *dev;
324	int subminor;
325	int retval = 0;
326	struct usb_interface *interface;
327
328	nonseekable_open(inode, file);
329	subminor = iminor(inode);
330
331	mutex_lock(&disconnect_mutex);
332
333	interface = usb_find_interface(&usb_alphatrack_driver, subminor);
334
335	if (!interface) {
336		err("%s - error, can't find device for minor %d\n",
337		    __func__, subminor);
338		retval = -ENODEV;
339		goto unlock_disconnect_exit;
340	}
341
342	dev = usb_get_intfdata(interface);
343
344	if (!dev) {
345		retval = -ENODEV;
346		goto unlock_disconnect_exit;
347	}
348
349	/* lock this device */
350	if (mutex_lock_interruptible(&dev->mtx)) {
351		retval = -ERESTARTSYS;
352		goto unlock_disconnect_exit;
353	}
354
355	/* allow opening only once */
356	if (dev->open_count) {
357		retval = -EBUSY;
358		goto unlock_exit;
359	}
360	dev->open_count = 1;
361
362	/* initialize in direction */
363	dev->ring_head = 0;
364	dev->ring_tail = 0;
365	usb_fill_int_urb(dev->interrupt_in_urb,
366			 interface_to_usbdev(interface),
367			 usb_rcvintpipe(interface_to_usbdev(interface),
368					dev->interrupt_in_endpoint->
369					bEndpointAddress),
370			 dev->interrupt_in_buffer,
371			 dev->interrupt_in_endpoint_size,
372			 usb_alphatrack_interrupt_in_callback, dev,
373			 dev->interrupt_in_interval);
374
375	dev->interrupt_in_running = 1;
376	dev->interrupt_in_done = 0;
377	dev->enable = 1;
378	dev->offline = 0;
379
380	retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
381	if (retval) {
382		dev_err(&interface->dev,
383			"Couldn't submit interrupt_in_urb %d\n", retval);
384		dev->interrupt_in_running = 0;
385		dev->open_count = 0;
386		goto unlock_exit;
387	}
388
389	/* save device in the file's private structure */
390	file->private_data = dev;
391
392unlock_exit:
393	mutex_unlock(&dev->mtx);
394
395unlock_disconnect_exit:
396	mutex_unlock(&disconnect_mutex);
397
398	return retval;
399}
400
401/**
402 *	usb_alphatrack_release
403 */
404static int usb_alphatrack_release(struct inode *inode, struct file *file)
405{
406	struct usb_alphatrack *dev;
407	int retval = 0;
408
409	dev = file->private_data;
410
411	if (dev == NULL) {
412		retval = -ENODEV;
413		goto exit;
414	}
415
416	if (mutex_lock_interruptible(&dev->mtx)) {
417		retval = -ERESTARTSYS;
418		goto exit;
419	}
420
421	if (dev->open_count != 1) {
422		retval = -ENODEV;
423		goto unlock_exit;
424	}
425
426	if (dev->intf == NULL) {
427		/* the device was unplugged before the file was released */
428		mutex_unlock(&dev->mtx);
429		/* unlock here as usb_alphatrack_delete frees dev */
430		usb_alphatrack_delete(dev);
431		retval = -ENODEV;
432		goto exit;
433	}
434
435	/* wait until write transfer is finished */
436	if (dev->interrupt_out_busy)
437		wait_event_interruptible_timeout(dev->write_wait,
438						 !dev->interrupt_out_busy,
439						 2 * HZ);
440	usb_alphatrack_abort_transfers(dev);
441	dev->open_count = 0;
442
443unlock_exit:
444	mutex_unlock(&dev->mtx);
445
446exit:
447	return retval;
448}
449
450/**
451 *	usb_alphatrack_poll
452 */
453static unsigned int usb_alphatrack_poll(struct file *file, poll_table *wait)
454{
455	struct usb_alphatrack *dev;
456	unsigned int mask = 0;
457
458	dev = file->private_data;
459
460	poll_wait(file, &dev->read_wait, wait);
461	poll_wait(file, &dev->write_wait, wait);
462
463	if (dev->ring_head != dev->ring_tail)
464		mask |= POLLIN | POLLRDNORM;
465	if (!dev->interrupt_out_busy)
466		mask |= POLLOUT | POLLWRNORM;
467
468	return mask;
469}
470
471/**
472 *	usb_alphatrack_read
473 */
474static ssize_t usb_alphatrack_read(struct file *file, char __user *buffer,
475				   size_t count, loff_t *ppos)
476{
477	struct usb_alphatrack *dev;
478	int retval = 0;
479
480	int c = 0;
481
482	dev = file->private_data;
483
484	/* verify that we actually have some data to read */
485	if (count == 0)
486		goto exit;
487
488	/* lock this object */
489	if (mutex_lock_interruptible(&dev->mtx)) {
490		retval = -ERESTARTSYS;
491		goto exit;
492	}
493
494	/* verify that the device wasn't unplugged */
495	if (dev->intf == NULL) {
496		retval = -ENODEV;
497		err("No device or device unplugged %d\n", retval);
498		goto unlock_exit;
499	}
500
501	while (dev->ring_head == dev->ring_tail) {
502		if (file->f_flags & O_NONBLOCK) {
503			retval = -EAGAIN;
504			goto unlock_exit;
505		}
506		dev->interrupt_in_done = 0;
507		retval =
508		    wait_event_interruptible(dev->read_wait,
509					     dev->interrupt_in_done);
510		if (retval < 0)
511			goto unlock_exit;
512	}
513
514	alphatrack_ocmd_info(&dev->intf->dev,
515			     &(*dev->ring_buffer)[dev->ring_tail].cmd, "%s",
516			     ": copying to userspace");
517
518	c = 0;
519	while ((c < count) && (dev->ring_tail != dev->ring_head)) {
520		if (copy_to_user
521		    (&buffer[c], &(*dev->ring_buffer)[dev->ring_tail],
522		     INPUT_CMD_SIZE)) {
523			retval = -EFAULT;
524			goto unlock_exit;
525		}
526		dev->ring_tail = (dev->ring_tail + 1) % ring_buffer_size;
527		c += INPUT_CMD_SIZE;
528		dbg_info(&dev->intf->dev, "%s: head, tail are %x, %x\n",
529			 __func__, dev->ring_head, dev->ring_tail);
530	}
531	retval = c;
532
533unlock_exit:
534	/* unlock the device */
535	mutex_unlock(&dev->mtx);
536
537exit:
538	return retval;
539}
540
541/**
542 *	usb_alphatrack_write
543 */
544static ssize_t usb_alphatrack_write(struct file *file,
545				    const char __user *buffer, size_t count,
546				    loff_t *ppos)
547{
548	struct usb_alphatrack *dev;
549	size_t bytes_to_write;
550	int retval = 0;
551
552	dev = file->private_data;
553
554	/* verify that we actually have some data to write */
555	if (count == 0)
556		goto exit;
557
558	/* lock this object */
559	if (mutex_lock_interruptible(&dev->mtx)) {
560		retval = -ERESTARTSYS;
561		goto exit;
562	}
563
564	/* verify that the device wasn't unplugged */
565	if (dev->intf == NULL) {
566		retval = -ENODEV;
567		err("No device or device unplugged %d\n", retval);
568		goto unlock_exit;
569	}
570
571	/* wait until previous transfer is finished */
572	if (dev->interrupt_out_busy) {
573		if (file->f_flags & O_NONBLOCK) {
574			retval = -EAGAIN;
575			goto unlock_exit;
576		}
577		retval =
578		    wait_event_interruptible(dev->write_wait,
579					     !dev->interrupt_out_busy);
580		if (retval < 0)
581			goto unlock_exit;
582	}
583
584	/* write the data into interrupt_out_buffer from userspace */
585	/* FIXME - if you write more than 12 bytes this breaks */
586	bytes_to_write =
587	    min(count, write_buffer_size * dev->interrupt_out_endpoint_size);
588	if (bytes_to_write < count)
589		dev_warn(&dev->intf->dev,
590			 "Write buffer overflow, %zd bytes dropped\n",
591			 count - bytes_to_write);
592
593	dbg_info(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\n",
594		 __func__, count, bytes_to_write);
595
596	if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
597		retval = -EFAULT;
598		goto unlock_exit;
599	}
600
601	if (dev->interrupt_out_endpoint == NULL) {
602		err("Endpoint should not be be null!\n");
603		goto unlock_exit;
604	}
605
606	/* send off the urb */
607	usb_fill_int_urb(dev->interrupt_out_urb,
608			 interface_to_usbdev(dev->intf),
609			 usb_sndintpipe(interface_to_usbdev(dev->intf),
610					dev->interrupt_out_endpoint->
611					bEndpointAddress),
612			 dev->interrupt_out_buffer, bytes_to_write,
613			 usb_alphatrack_interrupt_out_callback, dev,
614			 dev->interrupt_out_interval);
615	dev->interrupt_out_busy = 1;
616	atomic_inc(&dev->writes_pending);
617	wmb();
618
619	retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
620	if (retval) {
621		dev->interrupt_out_busy = 0;
622		err("Couldn't submit interrupt_out_urb %d\n", retval);
623		atomic_dec(&dev->writes_pending);
624		goto unlock_exit;
625	}
626	retval = bytes_to_write;
627
628unlock_exit:
629	/* unlock the device */
630	mutex_unlock(&dev->mtx);
631
632exit:
633	return retval;
634}
635
636/* file operations needed when we register this driver */
637static const struct file_operations usb_alphatrack_fops = {
638	.owner = THIS_MODULE,
639	.read = usb_alphatrack_read,
640	.write = usb_alphatrack_write,
641	.open = usb_alphatrack_open,
642	.release = usb_alphatrack_release,
643	.poll = usb_alphatrack_poll,
644	.llseek = no_llseek,
645};
646
647/*
648 * usb class driver info in order to get a minor number from the usb core,
649 * and to have the device registered with the driver core
650 */
651
652static struct usb_class_driver usb_alphatrack_class = {
653	.name = "alphatrack%d",
654	.fops = &usb_alphatrack_fops,
655	.minor_base = USB_ALPHATRACK_MINOR_BASE,
656};
657
658/**
659 *	usb_alphatrack_probe
660 *
661 *	Called by the usb core when a new device is connected that it thinks
662 *	this driver might be interested in.
663 */
664static int usb_alphatrack_probe(struct usb_interface *intf,
665				const struct usb_device_id *id)
666{
667	struct usb_device *udev = interface_to_usbdev(intf);
668	struct usb_alphatrack *dev = NULL;
669	struct usb_host_interface *iface_desc;
670	struct usb_endpoint_descriptor *endpoint;
671	int i;
672	int true_size;
673	int retval = -ENOMEM;
674
675	/* allocate memory for our device state and initialize it */
676
677	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
678	if (dev == NULL) {
679		dev_err(&intf->dev, "Out of memory\n");
680		goto exit;
681	}
682	mutex_init(&dev->mtx);
683	dev->intf = intf;
684	init_waitqueue_head(&dev->read_wait);
685	init_waitqueue_head(&dev->write_wait);
686
687	iface_desc = intf->cur_altsetting;
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(&intf->dev, "Interrupt in endpoint not found\n");
701		goto error;
702	}
703	if (dev->interrupt_out_endpoint == NULL)
704		dev_warn(&intf->dev,
705			 "Interrupt out endpoint not found"
706			 "(using control endpoint instead)\n");
707
708	dev->interrupt_in_endpoint_size =
709	    le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
710
711	if (dev->interrupt_in_endpoint_size != 64)
712		dev_warn(&intf->dev, "Interrupt in endpoint size is not 64!\n");
713
714	if (ring_buffer_size == 0)
715		ring_buffer_size = RING_BUFFER_SIZE;
716
717	true_size = min(ring_buffer_size, RING_BUFFER_SIZE);
718
719	/* FIXME - there are more usb_alloc routines for dma correctness.
720	   Needed? */
721	dev->ring_buffer =
722	    kmalloc((true_size * sizeof(struct alphatrack_icmd)), GFP_KERNEL);
723
724	if (!dev->ring_buffer) {
725		dev_err(&intf->dev,
726			"Couldn't allocate input ring_buffer of size %d\n",
727			true_size);
728		goto error;
729	}
730
731	dev->interrupt_in_buffer =
732	    kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
733
734	if (!dev->interrupt_in_buffer) {
735		dev_err(&intf->dev, "Couldn't allocate interrupt_in_buffer\n");
736		goto error;
737	}
738	dev->oldi_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
739	if (!dev->oldi_buffer) {
740		dev_err(&intf->dev, "Couldn't allocate old buffer\n");
741		goto error;
742	}
743	dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
744	if (!dev->interrupt_in_urb) {
745		dev_err(&intf->dev, "Couldn't allocate interrupt_in_urb\n");
746		goto error;
747	}
748
749	dev->interrupt_out_endpoint_size =
750	    dev->interrupt_out_endpoint ? le16_to_cpu(dev->
751						      interrupt_out_endpoint->
752						      wMaxPacketSize) : udev->
753	    descriptor.bMaxPacketSize0;
754
755	if (dev->interrupt_out_endpoint_size != 64)
756		dev_warn(&intf->dev,
757			 "Interrupt out endpoint size is not 64!)\n");
758
759	if (write_buffer_size == 0)
760		write_buffer_size = WRITE_BUFFER_SIZE;
761	true_size = min(write_buffer_size, WRITE_BUFFER_SIZE);
762
763	dev->interrupt_out_buffer =
764	    kmalloc(true_size * dev->interrupt_out_endpoint_size, GFP_KERNEL);
765
766	if (!dev->interrupt_out_buffer) {
767		dev_err(&intf->dev, "Couldn't allocate interrupt_out_buffer\n");
768		goto error;
769	}
770
771	dev->write_buffer =
772	    kmalloc(true_size * sizeof(struct alphatrack_ocmd), GFP_KERNEL);
773
774	if (!dev->write_buffer) {
775		dev_err(&intf->dev, "Couldn't allocate write_buffer\n");
776		goto error;
777	}
778
779	dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
780	if (!dev->interrupt_out_urb) {
781		dev_err(&intf->dev, "Couldn't allocate interrupt_out_urb\n");
782		goto error;
783	}
784	dev->interrupt_in_interval =
785	    min_interrupt_in_interval >
786	    dev->interrupt_in_endpoint->
787	    bInterval ? min_interrupt_in_interval : dev->interrupt_in_endpoint->
788	    bInterval;
789	if (dev->interrupt_out_endpoint)
790		dev->interrupt_out_interval =
791		    min_interrupt_out_interval >
792		    dev->interrupt_out_endpoint->
793		    bInterval ? min_interrupt_out_interval : dev->
794		    interrupt_out_endpoint->bInterval;
795
796	/* we can register the device now, as it is ready */
797	usb_set_intfdata(intf, dev);
798
799	atomic_set(&dev->writes_pending, 0);
800	retval = usb_register_dev(intf, &usb_alphatrack_class);
801	if (retval) {
802		/* something prevented us from registering this driver */
803		dev_err(&intf->dev,
804			"Not able to get a minor for this device.\n");
805		usb_set_intfdata(intf, NULL);
806		goto error;
807	}
808
809	/* let the user know what node this device is now attached to */
810	dev_info(&intf->dev,
811		 "Alphatrack Device #%d now attached to major %d minor %d\n",
812		 (intf->minor - USB_ALPHATRACK_MINOR_BASE), USB_MAJOR,
813		 intf->minor);
814
815exit:
816	return retval;
817
818error:
819	usb_alphatrack_delete(dev);
820
821	return retval;
822}
823
824/**
825 *	usb_alphatrack_disconnect
826 *
827 *	Called by the usb core when the device is removed from the system.
828 */
829static void usb_alphatrack_disconnect(struct usb_interface *intf)
830{
831	struct usb_alphatrack *dev;
832	int minor;
833
834	mutex_lock(&disconnect_mutex);
835
836	dev = usb_get_intfdata(intf);
837	usb_set_intfdata(intf, NULL);
838
839	mutex_lock(&dev->mtx);
840
841	minor = intf->minor;
842
843	/* give back our minor */
844	usb_deregister_dev(intf, &usb_alphatrack_class);
845
846	/* if the device is not opened, then we clean up right now */
847	if (!dev->open_count) {
848		mutex_unlock(&dev->mtx);
849		usb_alphatrack_delete(dev);
850	} else {
851		dev->intf = NULL;
852		mutex_unlock(&dev->mtx);
853	}
854
855	atomic_set(&dev->writes_pending, 0);
856	mutex_unlock(&disconnect_mutex);
857
858	dev_info(&intf->dev, "Alphatrack Surface #%d now disconnected\n",
859		 (minor - USB_ALPHATRACK_MINOR_BASE));
860}
861
862/* usb specific object needed to register this driver with the usb subsystem */
863static struct usb_driver usb_alphatrack_driver = {
864	.name = "alphatrack",
865	.probe = usb_alphatrack_probe,
866	.disconnect = usb_alphatrack_disconnect,
867	.id_table = usb_alphatrack_table,
868};
869
870module_usb_driver(usb_alphatrack_driver);
871