xref: /openbmc/linux/drivers/usb/misc/adutux.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
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
31 static int debug = 5;
32 #else
33 static int debug = 1;
34 #endif
35 
36 /* Use our own dbg macro */
37 #undef dbg
38 #define dbg(lvl, format, arg...) 					\
39 do { 									\
40 	if (debug >= lvl)						\
41 		printk(KERN_DEBUG __FILE__ " : " format " \n", ## 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 */
51 module_param(debug, int, S_IRUGO | S_IWUSR);
52 MODULE_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 */
59 static 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 
69 MODULE_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 /* Structure to hold all of our device specific stuff */
83 struct adu_device {
84 	struct mutex		mtx; /* locks this structure */
85 	struct usb_device*	udev; /* save off the usb device pointer */
86 	struct usb_interface*	interface;
87 	unsigned char		minor; /* the starting minor number for this device */
88 	char			serial_number[8];
89 
90 	int			open_count; /* number of times this port has been opened */
91 
92 	char*			read_buffer_primary;
93 	int			read_buffer_length;
94 	char*			read_buffer_secondary;
95 	int			secondary_head;
96 	int			secondary_tail;
97 	spinlock_t		buflock;
98 
99 	wait_queue_head_t	read_wait;
100 	wait_queue_head_t	write_wait;
101 
102 	char*			interrupt_in_buffer;
103 	struct usb_endpoint_descriptor* interrupt_in_endpoint;
104 	struct urb*		interrupt_in_urb;
105 	int			read_urb_finished;
106 
107 	char*			interrupt_out_buffer;
108 	struct usb_endpoint_descriptor* interrupt_out_endpoint;
109 	struct urb*		interrupt_out_urb;
110 };
111 
112 static struct usb_driver adu_driver;
113 
114 static void adu_debug_data(int level, const char *function, int size,
115 			   const unsigned char *data)
116 {
117 	int i;
118 
119 	if (debug < level)
120 		return;
121 
122 	printk(KERN_DEBUG __FILE__": %s - length = %d, data = ",
123 	       function, size);
124 	for (i = 0; i < size; ++i)
125 		printk("%.2x ", data[i]);
126 	printk("\n");
127 }
128 
129 /**
130  * adu_abort_transfers
131  *      aborts transfers and frees associated data structures
132  */
133 static void adu_abort_transfers(struct adu_device *dev)
134 {
135 	dbg(2," %s : enter", __FUNCTION__);
136 
137 	if (dev == NULL) {
138 		dbg(1," %s : dev is null", __FUNCTION__);
139 		goto exit;
140 	}
141 
142 	if (dev->udev == NULL) {
143 		dbg(1," %s : udev is null", __FUNCTION__);
144 		goto exit;
145 	}
146 
147 	dbg(2," %s : udev state %d", __FUNCTION__, dev->udev->state);
148 	if (dev->udev->state == USB_STATE_NOTATTACHED) {
149 		dbg(1," %s : udev is not attached", __FUNCTION__);
150 		goto exit;
151 	}
152 
153 	/* shutdown transfer */
154 	usb_unlink_urb(dev->interrupt_in_urb);
155 	usb_unlink_urb(dev->interrupt_out_urb);
156 
157 exit:
158 	dbg(2," %s : leave", __FUNCTION__);
159 }
160 
161 static void adu_delete(struct adu_device *dev)
162 {
163 	dbg(2, "%s enter", __FUNCTION__);
164 
165 	adu_abort_transfers(dev);
166 
167 	/* free data structures */
168 	usb_free_urb(dev->interrupt_in_urb);
169 	usb_free_urb(dev->interrupt_out_urb);
170 	kfree(dev->read_buffer_primary);
171 	kfree(dev->read_buffer_secondary);
172 	kfree(dev->interrupt_in_buffer);
173 	kfree(dev->interrupt_out_buffer);
174 	kfree(dev);
175 
176 	dbg(2, "%s : leave", __FUNCTION__);
177 }
178 
179 static void adu_interrupt_in_callback(struct urb *urb)
180 {
181 	struct adu_device *dev = urb->context;
182 	int status = urb->status;
183 
184 	dbg(4," %s : enter, status %d", __FUNCTION__, status);
185 	adu_debug_data(5, __FUNCTION__, urb->actual_length,
186 		       urb->transfer_buffer);
187 
188 	spin_lock(&dev->buflock);
189 
190 	if (status != 0) {
191 		if ((status != -ENOENT) && (status != -ECONNRESET) &&
192 			(status != -ESHUTDOWN)) {
193 			dbg(1," %s : nonzero status received: %d",
194 			    __FUNCTION__, status);
195 		}
196 		goto exit;
197 	}
198 
199 	if (urb->actual_length > 0 && dev->interrupt_in_buffer[0] != 0x00) {
200 		if (dev->read_buffer_length <
201 		    (4 * le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize)) -
202 		     (urb->actual_length)) {
203 			memcpy (dev->read_buffer_primary +
204 				dev->read_buffer_length,
205 				dev->interrupt_in_buffer, urb->actual_length);
206 
207 			dev->read_buffer_length += urb->actual_length;
208 			dbg(2," %s reading  %d ", __FUNCTION__,
209 			    urb->actual_length);
210 		} else {
211 			dbg(1," %s : read_buffer overflow", __FUNCTION__);
212 		}
213 	}
214 
215 exit:
216 	dev->read_urb_finished = 1;
217 	spin_unlock(&dev->buflock);
218 	/* always wake up so we recover from errors */
219 	wake_up_interruptible(&dev->read_wait);
220 	adu_debug_data(5, __FUNCTION__, urb->actual_length,
221 		       urb->transfer_buffer);
222 	dbg(4," %s : leave, status %d", __FUNCTION__, status);
223 }
224 
225 static void adu_interrupt_out_callback(struct urb *urb)
226 {
227 	struct adu_device *dev = urb->context;
228 	int status = urb->status;
229 
230 	dbg(4," %s : enter, status %d", __FUNCTION__, status);
231 	adu_debug_data(5,__FUNCTION__, urb->actual_length, urb->transfer_buffer);
232 
233 	if (status != 0) {
234 		if ((status != -ENOENT) &&
235 		    (status != -ECONNRESET)) {
236 			dbg(1, " %s :nonzero status received: %d",
237 			    __FUNCTION__, status);
238 		}
239 		goto exit;
240 	}
241 
242 	wake_up_interruptible(&dev->write_wait);
243 exit:
244 
245 	adu_debug_data(5, __FUNCTION__, urb->actual_length,
246 		       urb->transfer_buffer);
247 	dbg(4," %s : leave, status %d", __FUNCTION__, status);
248 }
249 
250 static int adu_open(struct inode *inode, struct file *file)
251 {
252 	struct adu_device *dev = NULL;
253 	struct usb_interface *interface;
254 	int subminor;
255 	int retval = 0;
256 
257 	dbg(2,"%s : enter", __FUNCTION__);
258 
259 	subminor = iminor(inode);
260 
261 	interface = usb_find_interface(&adu_driver, subminor);
262 	if (!interface) {
263 		err("%s - error, can't find device for minor %d",
264 		    __FUNCTION__, subminor);
265 		retval = -ENODEV;
266 		goto exit_no_device;
267 	}
268 
269 	dev = usb_get_intfdata(interface);
270 	if (!dev) {
271 		retval = -ENODEV;
272 		goto exit_no_device;
273 	}
274 
275 	/* lock this device */
276 	if ((retval = mutex_lock_interruptible(&dev->mtx))) {
277 		dbg(2, "%s : mutex lock failed", __FUNCTION__);
278 		goto exit_no_device;
279 	}
280 
281 	/* increment our usage count for the device */
282 	++dev->open_count;
283 	dbg(2,"%s : open count %d", __FUNCTION__, dev->open_count);
284 
285 	/* save device in the file's private structure */
286 	file->private_data = dev;
287 
288 	if (dev->open_count == 1) {
289 		/* initialize in direction */
290 		dev->read_buffer_length = 0;
291 
292 		/* fixup first read by having urb waiting for it */
293 		usb_fill_int_urb(dev->interrupt_in_urb,dev->udev,
294 				 usb_rcvintpipe(dev->udev,
295 				 		dev->interrupt_in_endpoint->bEndpointAddress),
296 				 dev->interrupt_in_buffer,
297 				 le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
298 				 adu_interrupt_in_callback, dev,
299 				 dev->interrupt_in_endpoint->bInterval);
300 		/* dev->interrupt_in_urb->transfer_flags |= URB_ASYNC_UNLINK; */
301 		dev->read_urb_finished = 0;
302 		retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
303 		if (retval)
304 			--dev->open_count;
305 	}
306 	mutex_unlock(&dev->mtx);
307 
308 exit_no_device:
309 	dbg(2,"%s : leave, return value %d ", __FUNCTION__, retval);
310 
311 	return retval;
312 }
313 
314 static int adu_release_internal(struct adu_device *dev)
315 {
316 	int retval = 0;
317 
318 	dbg(2," %s : enter", __FUNCTION__);
319 
320 	/* decrement our usage count for the device */
321 	--dev->open_count;
322 	dbg(2," %s : open count %d", __FUNCTION__, dev->open_count);
323 	if (dev->open_count <= 0) {
324 		adu_abort_transfers(dev);
325 		dev->open_count = 0;
326 	}
327 
328 	dbg(2," %s : leave", __FUNCTION__);
329 	return retval;
330 }
331 
332 static int adu_release(struct inode *inode, struct file *file)
333 {
334 	struct adu_device *dev = NULL;
335 	int retval = 0;
336 
337 	dbg(2," %s : enter", __FUNCTION__);
338 
339 	if (file == NULL) {
340  		dbg(1," %s : file is NULL", __FUNCTION__);
341 		retval = -ENODEV;
342 		goto exit;
343 	}
344 
345 	dev = file->private_data;
346 
347 	if (dev == NULL) {
348  		dbg(1," %s : object is NULL", __FUNCTION__);
349 		retval = -ENODEV;
350 		goto exit;
351 	}
352 
353 	/* lock our device */
354 	mutex_lock(&dev->mtx); /* not interruptible */
355 
356 	if (dev->open_count <= 0) {
357 		dbg(1," %s : device not opened", __FUNCTION__);
358 		retval = -ENODEV;
359 		goto exit;
360 	}
361 
362 	if (dev->udev == NULL) {
363 		/* the device was unplugged before the file was released */
364 		mutex_unlock(&dev->mtx);
365 		adu_delete(dev);
366 		dev = NULL;
367 	} else {
368 		/* do the work */
369 		retval = adu_release_internal(dev);
370 	}
371 
372 exit:
373 	if (dev)
374 		mutex_unlock(&dev->mtx);
375 	dbg(2," %s : leave, return value %d", __FUNCTION__, retval);
376 	return retval;
377 }
378 
379 static ssize_t adu_read(struct file *file, __user char *buffer, size_t count,
380 			loff_t *ppos)
381 {
382 	struct adu_device *dev;
383 	size_t bytes_read = 0;
384 	size_t bytes_to_read = count;
385 	int i;
386 	int retval = 0;
387 	int timeout = 0;
388 	int should_submit = 0;
389 	unsigned long flags;
390 	DECLARE_WAITQUEUE(wait, current);
391 
392 	dbg(2," %s : enter, count = %Zd, file=%p", __FUNCTION__, count, file);
393 
394 	dev = file->private_data;
395 	dbg(2," %s : dev=%p", __FUNCTION__, dev);
396 	/* lock this object */
397 	if (mutex_lock_interruptible(&dev->mtx))
398 		return -ERESTARTSYS;
399 
400 	/* verify that the device wasn't unplugged */
401 	if (dev->udev == NULL || dev->minor == 0) {
402 		retval = -ENODEV;
403 		err("No device or device unplugged %d", retval);
404 		goto exit;
405 	}
406 
407 	/* verify that some data was requested */
408 	if (count == 0) {
409 		dbg(1," %s : read request of 0 bytes", __FUNCTION__);
410 		goto exit;
411 	}
412 
413 	timeout = COMMAND_TIMEOUT;
414 	dbg(2," %s : about to start looping", __FUNCTION__);
415 	while (bytes_to_read) {
416 		int data_in_secondary = dev->secondary_tail - dev->secondary_head;
417 		dbg(2," %s : while, data_in_secondary=%d, status=%d",
418 		    __FUNCTION__, data_in_secondary,
419 		    dev->interrupt_in_urb->status);
420 
421 		if (data_in_secondary) {
422 			/* drain secondary buffer */
423 			int amount = bytes_to_read < data_in_secondary ? bytes_to_read : data_in_secondary;
424 			i = copy_to_user(buffer, dev->read_buffer_secondary+dev->secondary_head, amount);
425 			if (i < 0) {
426 				retval = -EFAULT;
427 				goto exit;
428 			}
429 			dev->secondary_head += (amount - i);
430 			bytes_read += (amount - i);
431 			bytes_to_read -= (amount - i);
432 			if (i) {
433 				retval = bytes_read ? bytes_read : -EFAULT;
434 				goto exit;
435 			}
436 		} else {
437 			/* we check the primary buffer */
438 			spin_lock_irqsave (&dev->buflock, flags);
439 			if (dev->read_buffer_length) {
440 				/* we secure access to the primary */
441 				char *tmp;
442 				dbg(2," %s : swap, read_buffer_length = %d",
443 				    __FUNCTION__, dev->read_buffer_length);
444 				tmp = dev->read_buffer_secondary;
445 				dev->read_buffer_secondary = dev->read_buffer_primary;
446 				dev->read_buffer_primary = tmp;
447 				dev->secondary_head = 0;
448 				dev->secondary_tail = dev->read_buffer_length;
449 				dev->read_buffer_length = 0;
450 				spin_unlock_irqrestore(&dev->buflock, flags);
451 				/* we have a free buffer so use it */
452 				should_submit = 1;
453 			} else {
454 				/* even the primary was empty - we may need to do IO */
455 				if (dev->interrupt_in_urb->status == -EINPROGRESS) {
456 					/* somebody is doing IO */
457 					spin_unlock_irqrestore(&dev->buflock, flags);
458 					dbg(2," %s : submitted already", __FUNCTION__);
459 				} else {
460 					/* we must initiate input */
461 					dbg(2," %s : initiate input", __FUNCTION__);
462 					dev->read_urb_finished = 0;
463 
464 					usb_fill_int_urb(dev->interrupt_in_urb,dev->udev,
465 							 usb_rcvintpipe(dev->udev,
466 							 		dev->interrupt_in_endpoint->bEndpointAddress),
467 							 dev->interrupt_in_buffer,
468 							 le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
469 							 adu_interrupt_in_callback,
470 							 dev,
471 							 dev->interrupt_in_endpoint->bInterval);
472 					retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
473 					if (!retval) {
474 						spin_unlock_irqrestore(&dev->buflock, flags);
475 						dbg(2," %s : submitted OK", __FUNCTION__);
476 					} else {
477 						if (retval == -ENOMEM) {
478 							retval = bytes_read ? bytes_read : -ENOMEM;
479 						}
480 						spin_unlock_irqrestore(&dev->buflock, flags);
481 						dbg(2," %s : submit failed", __FUNCTION__);
482 						goto exit;
483 					}
484 				}
485 
486 				/* we wait for I/O to complete */
487 				set_current_state(TASK_INTERRUPTIBLE);
488 				add_wait_queue(&dev->read_wait, &wait);
489 				if (!dev->read_urb_finished)
490 					timeout = schedule_timeout(COMMAND_TIMEOUT);
491 				else
492 					set_current_state(TASK_RUNNING);
493 				remove_wait_queue(&dev->read_wait, &wait);
494 
495 				if (timeout <= 0) {
496 					dbg(2," %s : timeout", __FUNCTION__);
497 					retval = bytes_read ? bytes_read : -ETIMEDOUT;
498 					goto exit;
499 				}
500 
501 				if (signal_pending(current)) {
502 					dbg(2," %s : signal pending", __FUNCTION__);
503 					retval = bytes_read ? bytes_read : -EINTR;
504 					goto exit;
505 				}
506 			}
507 		}
508 	}
509 
510 	retval = bytes_read;
511 	/* if the primary buffer is empty then use it */
512 	if (should_submit && !dev->interrupt_in_urb->status==-EINPROGRESS) {
513 		usb_fill_int_urb(dev->interrupt_in_urb,dev->udev,
514 				 usb_rcvintpipe(dev->udev,
515 				 		dev->interrupt_in_endpoint->bEndpointAddress),
516 						dev->interrupt_in_buffer,
517 						le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
518 						adu_interrupt_in_callback,
519 						dev,
520 						dev->interrupt_in_endpoint->bInterval);
521 		/* dev->interrupt_in_urb->transfer_flags |= URB_ASYNC_UNLINK; */
522 		dev->read_urb_finished = 0;
523 		usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
524 		/* we ignore failure */
525 	}
526 
527 exit:
528 	/* unlock the device */
529 	mutex_unlock(&dev->mtx);
530 
531 	dbg(2," %s : leave, return value %d", __FUNCTION__, retval);
532 	return retval;
533 }
534 
535 static ssize_t adu_write(struct file *file, const __user char *buffer,
536 			 size_t count, loff_t *ppos)
537 {
538 	struct adu_device *dev;
539 	size_t bytes_written = 0;
540 	size_t bytes_to_write;
541 	size_t buffer_size;
542 	int retval;
543 	int timeout = 0;
544 
545 	dbg(2," %s : enter, count = %Zd", __FUNCTION__, count);
546 
547 	dev = file->private_data;
548 
549 	/* lock this object */
550 	retval = mutex_lock_interruptible(&dev->mtx);
551 	if (retval)
552 		goto exit_nolock;
553 
554 	/* verify that the device wasn't unplugged */
555 	if (dev->udev == NULL || dev->minor == 0) {
556 		retval = -ENODEV;
557 		err("No device or device unplugged %d", retval);
558 		goto exit;
559 	}
560 
561 	/* verify that we actually have some data to write */
562 	if (count == 0) {
563 		dbg(1," %s : write request of 0 bytes", __FUNCTION__);
564 		goto exit;
565 	}
566 
567 
568 	while (count > 0) {
569 		if (dev->interrupt_out_urb->status == -EINPROGRESS) {
570 			timeout = COMMAND_TIMEOUT;
571 
572 			while (timeout > 0) {
573 				if (signal_pending(current)) {
574 				dbg(1," %s : interrupted", __FUNCTION__);
575 				retval = -EINTR;
576 				goto exit;
577 			}
578 			mutex_unlock(&dev->mtx);
579 			timeout = interruptible_sleep_on_timeout(&dev->write_wait, timeout);
580 			retval = mutex_lock_interruptible(&dev->mtx);
581 			if (retval) {
582 				retval = bytes_written ? bytes_written : retval;
583 				goto exit_nolock;
584 			}
585 			if (timeout > 0) {
586 				break;
587 			}
588 			dbg(1," %s : interrupted timeout: %d", __FUNCTION__, timeout);
589 		}
590 
591 
592 		dbg(1," %s : final timeout: %d", __FUNCTION__, timeout);
593 
594 		if (timeout == 0) {
595 			dbg(1, "%s - command timed out.", __FUNCTION__);
596 			retval = -ETIMEDOUT;
597 			goto exit;
598 		}
599 
600 		dbg(4," %s : in progress, count = %Zd", __FUNCTION__, count);
601 
602 		} else {
603 			dbg(4," %s : sending, count = %Zd", __FUNCTION__, count);
604 
605 			/* write the data into interrupt_out_buffer from userspace */
606 			buffer_size = le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize);
607 			bytes_to_write = count > buffer_size ? buffer_size : count;
608 			dbg(4," %s : buffer_size = %Zd, count = %Zd, bytes_to_write = %Zd",
609 			    __FUNCTION__, buffer_size, count, bytes_to_write);
610 
611 			if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write) != 0) {
612 				retval = -EFAULT;
613 				goto exit;
614 			}
615 
616 			/* send off the urb */
617 			usb_fill_int_urb(
618 				dev->interrupt_out_urb,
619 				dev->udev,
620 				usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
621 				dev->interrupt_out_buffer,
622 				bytes_to_write,
623 				adu_interrupt_out_callback,
624 				dev,
625 				dev->interrupt_in_endpoint->bInterval);
626 			/* dev->interrupt_in_urb->transfer_flags |= URB_ASYNC_UNLINK; */
627 			dev->interrupt_out_urb->actual_length = bytes_to_write;
628 			retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
629 			if (retval < 0) {
630 				err("Couldn't submit interrupt_out_urb %d", retval);
631 				goto exit;
632 			}
633 
634 			buffer += bytes_to_write;
635 			count -= bytes_to_write;
636 
637 			bytes_written += bytes_to_write;
638 		}
639 	}
640 
641 	retval = bytes_written;
642 
643 exit:
644 	/* unlock the device */
645 	mutex_unlock(&dev->mtx);
646 exit_nolock:
647 
648 	dbg(2," %s : leave, return value %d", __FUNCTION__, retval);
649 
650 	return retval;
651 }
652 
653 /* file operations needed when we register this driver */
654 static const struct file_operations adu_fops = {
655 	.owner = THIS_MODULE,
656 	.read  = adu_read,
657 	.write = adu_write,
658 	.open = adu_open,
659 	.release = adu_release,
660 };
661 
662 /*
663  * usb class driver info in order to get a minor number from the usb core,
664  * and to have the device registered with devfs and the driver core
665  */
666 static struct usb_class_driver adu_class = {
667 	.name = "usb/adutux%d",
668 	.fops = &adu_fops,
669 	.minor_base = ADU_MINOR_BASE,
670 };
671 
672 /**
673  * adu_probe
674  *
675  * Called by the usb core when a new device is connected that it thinks
676  * this driver might be interested in.
677  */
678 static int adu_probe(struct usb_interface *interface,
679 		     const struct usb_device_id *id)
680 {
681 	struct usb_device *udev = interface_to_usbdev(interface);
682 	struct adu_device *dev = NULL;
683 	struct usb_host_interface *iface_desc;
684 	struct usb_endpoint_descriptor *endpoint;
685 	int retval = -ENODEV;
686 	int in_end_size;
687 	int out_end_size;
688 	int i;
689 
690 	dbg(2," %s : enter", __FUNCTION__);
691 
692 	if (udev == NULL) {
693 		dev_err(&interface->dev, "udev is NULL.\n");
694 		goto exit;
695 	}
696 
697 	/* allocate memory for our device state and intialize it */
698 	dev = kzalloc(sizeof(struct adu_device), GFP_KERNEL);
699 	if (dev == NULL) {
700 		dev_err(&interface->dev, "Out of memory\n");
701 		retval = -ENOMEM;
702 		goto exit;
703 	}
704 
705 	mutex_init(&dev->mtx);
706 	spin_lock_init(&dev->buflock);
707 	dev->udev = udev;
708 	init_waitqueue_head(&dev->read_wait);
709 	init_waitqueue_head(&dev->write_wait);
710 
711 	iface_desc = &interface->altsetting[0];
712 
713 	/* set up the endpoint information */
714 	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
715 		endpoint = &iface_desc->endpoint[i].desc;
716 
717 		if (usb_endpoint_is_int_in(endpoint))
718 			dev->interrupt_in_endpoint = endpoint;
719 
720 		if (usb_endpoint_is_int_out(endpoint))
721 			dev->interrupt_out_endpoint = endpoint;
722 	}
723 	if (dev->interrupt_in_endpoint == NULL) {
724 		dev_err(&interface->dev, "interrupt in endpoint not found\n");
725 		goto error;
726 	}
727 	if (dev->interrupt_out_endpoint == NULL) {
728 		dev_err(&interface->dev, "interrupt out endpoint not found\n");
729 		goto error;
730 	}
731 
732 	in_end_size = le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
733 	out_end_size = le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize);
734 
735 	dev->read_buffer_primary = kmalloc((4 * in_end_size), GFP_KERNEL);
736 	if (!dev->read_buffer_primary) {
737 		dev_err(&interface->dev, "Couldn't allocate read_buffer_primary\n");
738 		retval = -ENOMEM;
739 		goto error;
740 	}
741 
742 	/* debug code prime the buffer */
743 	memset(dev->read_buffer_primary, 'a', in_end_size);
744 	memset(dev->read_buffer_primary + in_end_size, 'b', in_end_size);
745 	memset(dev->read_buffer_primary + (2 * in_end_size), 'c', in_end_size);
746 	memset(dev->read_buffer_primary + (3 * in_end_size), 'd', in_end_size);
747 
748 	dev->read_buffer_secondary = kmalloc((4 * in_end_size), GFP_KERNEL);
749 	if (!dev->read_buffer_secondary) {
750 		dev_err(&interface->dev, "Couldn't allocate read_buffer_secondary\n");
751 		retval = -ENOMEM;
752 		goto error;
753 	}
754 
755 	/* debug code prime the buffer */
756 	memset(dev->read_buffer_secondary, 'e', in_end_size);
757 	memset(dev->read_buffer_secondary + in_end_size, 'f', in_end_size);
758 	memset(dev->read_buffer_secondary + (2 * in_end_size), 'g', in_end_size);
759 	memset(dev->read_buffer_secondary + (3 * in_end_size), 'h', in_end_size);
760 
761 	dev->interrupt_in_buffer = kmalloc(in_end_size, GFP_KERNEL);
762 	if (!dev->interrupt_in_buffer) {
763 		dev_err(&interface->dev, "Couldn't allocate interrupt_in_buffer\n");
764 		goto error;
765 	}
766 
767 	/* debug code prime the buffer */
768 	memset(dev->interrupt_in_buffer, 'i', in_end_size);
769 
770 	dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
771 	if (!dev->interrupt_in_urb) {
772 		dev_err(&interface->dev, "Couldn't allocate interrupt_in_urb\n");
773 		goto error;
774 	}
775 	dev->interrupt_out_buffer = kmalloc(out_end_size, GFP_KERNEL);
776 	if (!dev->interrupt_out_buffer) {
777 		dev_err(&interface->dev, "Couldn't allocate interrupt_out_buffer\n");
778 		goto error;
779 	}
780 	dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
781 	if (!dev->interrupt_out_urb) {
782 		dev_err(&interface->dev, "Couldn't allocate interrupt_out_urb\n");
783 		goto error;
784 	}
785 
786 	if (!usb_string(udev, udev->descriptor.iSerialNumber, dev->serial_number,
787 			sizeof(dev->serial_number))) {
788 		dev_err(&interface->dev, "Could not retrieve serial number\n");
789 		goto error;
790 	}
791 	dbg(2," %s : serial_number=%s", __FUNCTION__, dev->serial_number);
792 
793 	/* we can register the device now, as it is ready */
794 	usb_set_intfdata(interface, dev);
795 
796 	retval = usb_register_dev(interface, &adu_class);
797 
798 	if (retval) {
799 		/* something prevented us from registering this driver */
800 		dev_err(&interface->dev, "Not able to get a minor for this device.\n");
801 		usb_set_intfdata(interface, NULL);
802 		goto error;
803 	}
804 
805 	dev->minor = interface->minor;
806 
807 	/* let the user know what node this device is now attached to */
808 	dev_info(&interface->dev, "ADU%d %s now attached to /dev/usb/adutux%d\n",
809 		 udev->descriptor.idProduct, dev->serial_number,
810 		 (dev->minor - ADU_MINOR_BASE));
811 exit:
812 	dbg(2," %s : leave, return value %p (dev)", __FUNCTION__, dev);
813 
814 	return retval;
815 
816 error:
817 	adu_delete(dev);
818 	return retval;
819 }
820 
821 /**
822  * adu_disconnect
823  *
824  * Called by the usb core when the device is removed from the system.
825  */
826 static void adu_disconnect(struct usb_interface *interface)
827 {
828 	struct adu_device *dev;
829 	int minor;
830 
831 	dbg(2," %s : enter", __FUNCTION__);
832 
833 	dev = usb_get_intfdata(interface);
834 	usb_set_intfdata(interface, NULL);
835 
836 	minor = dev->minor;
837 
838 	/* give back our minor */
839 	usb_deregister_dev(interface, &adu_class);
840 	dev->minor = 0;
841 
842 	mutex_lock(&dev->mtx); /* not interruptible */
843 
844 	/* if the device is not opened, then we clean up right now */
845 	dbg(2," %s : open count %d", __FUNCTION__, dev->open_count);
846 	if (!dev->open_count) {
847 		mutex_unlock(&dev->mtx);
848 		adu_delete(dev);
849 	} else {
850 		dev->udev = NULL;
851 		mutex_unlock(&dev->mtx);
852 	}
853 
854 	dev_info(&interface->dev, "ADU device adutux%d now disconnected\n",
855 		 (minor - ADU_MINOR_BASE));
856 
857 	dbg(2," %s : leave", __FUNCTION__);
858 }
859 
860 /* usb specific object needed to register this driver with the usb subsystem */
861 static struct usb_driver adu_driver = {
862 	.name = "adutux",
863 	.probe = adu_probe,
864 	.disconnect = adu_disconnect,
865 	.id_table = device_table,
866 };
867 
868 static int __init adu_init(void)
869 {
870 	int result;
871 
872 	dbg(2," %s : enter", __FUNCTION__);
873 
874 	/* register this driver with the USB subsystem */
875 	result = usb_register(&adu_driver);
876 	if (result < 0) {
877 		err("usb_register failed for the "__FILE__" driver. "
878 		    "Error number %d", result);
879 		goto exit;
880 	}
881 
882 	info("adutux " DRIVER_DESC " " DRIVER_VERSION);
883 	info("adutux is an experimental driver. Use at your own risk");
884 
885 exit:
886 	dbg(2," %s : leave, return value %d", __FUNCTION__, result);
887 
888 	return result;
889 }
890 
891 static void __exit adu_exit(void)
892 {
893 	dbg(2," %s : enter", __FUNCTION__);
894 	/* deregister this driver with the USB subsystem */
895 	usb_deregister(&adu_driver);
896 	dbg(2," %s : leave", __FUNCTION__);
897 }
898 
899 module_init(adu_init);
900 module_exit(adu_exit);
901 
902 MODULE_AUTHOR(DRIVER_AUTHOR);
903 MODULE_DESCRIPTION(DRIVER_DESC);
904 MODULE_LICENSE("GPL");
905