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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * adutux - driver for ADU devices from Ontrak Control Systems
4 * This is an experimental driver. Use at your own risk.
5 * This driver is not supported by Ontrak Control Systems.
6 *
7 * Copyright (c) 2003 John Homppi (SCO, leave this notice here)
8 *
9 * derived from the Lego USB Tower driver 0.56:
10 * Copyright (c) 2003 David Glance <davidgsf@sourceforge.net>
11 * 2001 Juergen Stuber <stuber@loria.fr>
12 * that was derived from USB Skeleton driver - 0.5
13 * Copyright (c) 2001 Greg Kroah-Hartman (greg@kroah.com)
14 *
15 */
16
17#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18
19#include <linux/kernel.h>
20#include <linux/sched/signal.h>
21#include <linux/errno.h>
22#include <linux/slab.h>
23#include <linux/module.h>
24#include <linux/usb.h>
25#include <linux/mutex.h>
26#include <linux/uaccess.h>
27
28#define DRIVER_AUTHOR "John Homppi"
29#define DRIVER_DESC "adutux (see www.ontrak.net)"
30
31/* Define these values to match your device */
32#define ADU_VENDOR_ID 0x0a07
33#define ADU_PRODUCT_ID 0x0064
34
35/* table of devices that work with this driver */
36static const struct usb_device_id device_table[] = {
37 { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID) }, /* ADU100 */
38 { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+20) }, /* ADU120 */
39 { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+30) }, /* ADU130 */
40 { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+100) }, /* ADU200 */
41 { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+108) }, /* ADU208 */
42 { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+118) }, /* ADU218 */
43 { } /* Terminating entry */
44};
45
46MODULE_DEVICE_TABLE(usb, device_table);
47
48#ifdef CONFIG_USB_DYNAMIC_MINORS
49#define ADU_MINOR_BASE 0
50#else
51#define ADU_MINOR_BASE 67
52#endif
53
54/* we can have up to this number of device plugged in at once */
55#define MAX_DEVICES 16
56
57#define COMMAND_TIMEOUT (2*HZ)
58
59/*
60 * The locking scheme is a vanilla 3-lock:
61 * adu_device.buflock: A spinlock, covers what IRQs touch.
62 * adutux_mutex: A Static lock to cover open_count. It would also cover
63 * any globals, but we don't have them in 2.6.
64 * adu_device.mtx: A mutex to hold across sleepers like copy_from_user.
65 * It covers all of adu_device, except the open_count
66 * and what .buflock covers.
67 */
68
69/* Structure to hold all of our device specific stuff */
70struct adu_device {
71 struct mutex mtx;
72 struct usb_device *udev; /* save off the usb device pointer */
73 struct usb_interface *interface;
74 unsigned int minor; /* the starting minor number for this device */
75 char serial_number[8];
76
77 int open_count; /* number of times this port has been opened */
78 unsigned long disconnected:1;
79
80 char *read_buffer_primary;
81 int read_buffer_length;
82 char *read_buffer_secondary;
83 int secondary_head;
84 int secondary_tail;
85 spinlock_t buflock;
86
87 wait_queue_head_t read_wait;
88 wait_queue_head_t write_wait;
89
90 char *interrupt_in_buffer;
91 struct usb_endpoint_descriptor *interrupt_in_endpoint;
92 struct urb *interrupt_in_urb;
93 int read_urb_finished;
94
95 char *interrupt_out_buffer;
96 struct usb_endpoint_descriptor *interrupt_out_endpoint;
97 struct urb *interrupt_out_urb;
98 int out_urb_finished;
99};
100
101static DEFINE_MUTEX(adutux_mutex);
102
103static struct usb_driver adu_driver;
104
105static inline void adu_debug_data(struct device *dev, const char *function,
106 int size, const unsigned char *data)
107{
108 dev_dbg(dev, "%s - length = %d, data = %*ph\n",
109 function, size, size, data);
110}
111
112/*
113 * adu_abort_transfers
114 * aborts transfers and frees associated data structures
115 */
116static void adu_abort_transfers(struct adu_device *dev)
117{
118 unsigned long flags;
119
120 if (dev->disconnected)
121 return;
122
123 /* shutdown transfer */
124
125 /* XXX Anchor these instead */
126 spin_lock_irqsave(&dev->buflock, flags);
127 if (!dev->read_urb_finished) {
128 spin_unlock_irqrestore(&dev->buflock, flags);
129 usb_kill_urb(dev->interrupt_in_urb);
130 } else
131 spin_unlock_irqrestore(&dev->buflock, flags);
132
133 spin_lock_irqsave(&dev->buflock, flags);
134 if (!dev->out_urb_finished) {
135 spin_unlock_irqrestore(&dev->buflock, flags);
136 wait_event_timeout(dev->write_wait, dev->out_urb_finished,
137 COMMAND_TIMEOUT);
138 usb_kill_urb(dev->interrupt_out_urb);
139 } else
140 spin_unlock_irqrestore(&dev->buflock, flags);
141}
142
143static void adu_delete(struct adu_device *dev)
144{
145 /* free data structures */
146 usb_free_urb(dev->interrupt_in_urb);
147 usb_free_urb(dev->interrupt_out_urb);
148 kfree(dev->read_buffer_primary);
149 kfree(dev->read_buffer_secondary);
150 kfree(dev->interrupt_in_buffer);
151 kfree(dev->interrupt_out_buffer);
152 usb_put_dev(dev->udev);
153 kfree(dev);
154}
155
156static void adu_interrupt_in_callback(struct urb *urb)
157{
158 struct adu_device *dev = urb->context;
159 int status = urb->status;
160 unsigned long flags;
161
162 adu_debug_data(&dev->udev->dev, __func__,
163 urb->actual_length, urb->transfer_buffer);
164
165 spin_lock_irqsave(&dev->buflock, flags);
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_irqrestore(&dev->buflock, flags);
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 unsigned long flags;
206
207 adu_debug_data(&dev->udev->dev, __func__,
208 urb->actual_length, urb->transfer_buffer);
209
210 if (status != 0) {
211 if ((status != -ENOENT) &&
212 (status != -ECONNRESET)) {
213 dev_dbg(&dev->udev->dev,
214 "%s :nonzero status received: %d\n", __func__,
215 status);
216 }
217 return;
218 }
219
220 spin_lock_irqsave(&dev->buflock, flags);
221 dev->out_urb_finished = 1;
222 wake_up(&dev->write_wait);
223 spin_unlock_irqrestore(&dev->buflock, flags);
224}
225
226static int adu_open(struct inode *inode, struct file *file)
227{
228 struct adu_device *dev = NULL;
229 struct usb_interface *interface;
230 int subminor;
231 int retval;
232
233 subminor = iminor(inode);
234
235 retval = mutex_lock_interruptible(&adutux_mutex);
236 if (retval)
237 goto exit_no_lock;
238
239 interface = usb_find_interface(&adu_driver, subminor);
240 if (!interface) {
241 pr_err("%s - error, can't find device for minor %d\n",
242 __func__, subminor);
243 retval = -ENODEV;
244 goto exit_no_device;
245 }
246
247 dev = usb_get_intfdata(interface);
248 if (!dev) {
249 retval = -ENODEV;
250 goto exit_no_device;
251 }
252
253 /* check that nobody else is using the device */
254 if (dev->open_count) {
255 retval = -EBUSY;
256 goto exit_no_device;
257 }
258
259 ++dev->open_count;
260 dev_dbg(&dev->udev->dev, "%s: open count %d\n", __func__,
261 dev->open_count);
262
263 /* save device in the file's private structure */
264 file->private_data = dev;
265
266 /* initialize in direction */
267 dev->read_buffer_length = 0;
268
269 /* fixup first read by having urb waiting for it */
270 usb_fill_int_urb(dev->interrupt_in_urb, dev->udev,
271 usb_rcvintpipe(dev->udev,
272 dev->interrupt_in_endpoint->bEndpointAddress),
273 dev->interrupt_in_buffer,
274 usb_endpoint_maxp(dev->interrupt_in_endpoint),
275 adu_interrupt_in_callback, dev,
276 dev->interrupt_in_endpoint->bInterval);
277 dev->read_urb_finished = 0;
278 if (usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL))
279 dev->read_urb_finished = 1;
280 /* we ignore failure */
281 /* end of fixup for first read */
282
283 /* initialize out direction */
284 dev->out_urb_finished = 1;
285
286 retval = 0;
287
288exit_no_device:
289 mutex_unlock(&adutux_mutex);
290exit_no_lock:
291 return retval;
292}
293
294static void adu_release_internal(struct adu_device *dev)
295{
296 /* decrement our usage count for the device */
297 --dev->open_count;
298 dev_dbg(&dev->udev->dev, "%s : open count %d\n", __func__,
299 dev->open_count);
300 if (dev->open_count <= 0) {
301 adu_abort_transfers(dev);
302 dev->open_count = 0;
303 }
304}
305
306static int adu_release(struct inode *inode, struct file *file)
307{
308 struct adu_device *dev;
309 int retval = 0;
310
311 if (file == NULL) {
312 retval = -ENODEV;
313 goto exit;
314 }
315
316 dev = file->private_data;
317 if (dev == NULL) {
318 retval = -ENODEV;
319 goto exit;
320 }
321
322 mutex_lock(&adutux_mutex); /* not interruptible */
323
324 if (dev->open_count <= 0) {
325 dev_dbg(&dev->udev->dev, "%s : device not opened\n", __func__);
326 retval = -ENODEV;
327 goto unlock;
328 }
329
330 adu_release_internal(dev);
331 if (dev->disconnected) {
332 /* the device was unplugged before the file was released */
333 if (!dev->open_count) /* ... and we're the last user */
334 adu_delete(dev);
335 }
336unlock:
337 mutex_unlock(&adutux_mutex);
338exit:
339 return retval;
340}
341
342static ssize_t adu_read(struct file *file, __user char *buffer, size_t count,
343 loff_t *ppos)
344{
345 struct adu_device *dev;
346 size_t bytes_read = 0;
347 size_t bytes_to_read = count;
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->disconnected) {
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 size_t data_in_secondary = dev->secondary_tail - dev->secondary_head;
376 dev_dbg(&dev->udev->dev,
377 "%s : while, data_in_secondary=%zu, 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 size_t amount = min(bytes_to_read, data_in_secondary);
384 if (copy_to_user(buffer, dev->read_buffer_secondary+dev->secondary_head, amount)) {
385 retval = -EFAULT;
386 goto exit;
387 }
388 dev->secondary_head += amount;
389 bytes_read += amount;
390 bytes_to_read -= amount;
391 } else {
392 /* we check the primary buffer */
393 spin_lock_irqsave (&dev->buflock, flags);
394 if (dev->read_buffer_length) {
395 /* we secure access to the primary */
396 char *tmp;
397 dev_dbg(&dev->udev->dev,
398 "%s : swap, read_buffer_length = %d\n",
399 __func__, dev->read_buffer_length);
400 tmp = dev->read_buffer_secondary;
401 dev->read_buffer_secondary = dev->read_buffer_primary;
402 dev->read_buffer_primary = tmp;
403 dev->secondary_head = 0;
404 dev->secondary_tail = dev->read_buffer_length;
405 dev->read_buffer_length = 0;
406 spin_unlock_irqrestore(&dev->buflock, flags);
407 /* we have a free buffer so use it */
408 should_submit = 1;
409 } else {
410 /* even the primary was empty - we may need to do IO */
411 if (!dev->read_urb_finished) {
412 /* somebody is doing IO */
413 spin_unlock_irqrestore(&dev->buflock, flags);
414 dev_dbg(&dev->udev->dev,
415 "%s : submitted already\n",
416 __func__);
417 } else {
418 /* we must initiate input */
419 dev_dbg(&dev->udev->dev,
420 "%s : initiate input\n",
421 __func__);
422 dev->read_urb_finished = 0;
423 spin_unlock_irqrestore(&dev->buflock, flags);
424
425 usb_fill_int_urb(dev->interrupt_in_urb, dev->udev,
426 usb_rcvintpipe(dev->udev,
427 dev->interrupt_in_endpoint->bEndpointAddress),
428 dev->interrupt_in_buffer,
429 usb_endpoint_maxp(dev->interrupt_in_endpoint),
430 adu_interrupt_in_callback,
431 dev,
432 dev->interrupt_in_endpoint->bInterval);
433 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
434 if (retval) {
435 dev->read_urb_finished = 1;
436 if (retval == -ENOMEM) {
437 retval = bytes_read ? bytes_read : -ENOMEM;
438 }
439 dev_dbg(&dev->udev->dev,
440 "%s : submit failed\n",
441 __func__);
442 goto exit;
443 }
444 }
445
446 /* we wait for I/O to complete */
447 set_current_state(TASK_INTERRUPTIBLE);
448 add_wait_queue(&dev->read_wait, &wait);
449 spin_lock_irqsave(&dev->buflock, flags);
450 if (!dev->read_urb_finished) {
451 spin_unlock_irqrestore(&dev->buflock, flags);
452 timeout = schedule_timeout(COMMAND_TIMEOUT);
453 } else {
454 spin_unlock_irqrestore(&dev->buflock, flags);
455 set_current_state(TASK_RUNNING);
456 }
457 remove_wait_queue(&dev->read_wait, &wait);
458
459 if (timeout <= 0) {
460 dev_dbg(&dev->udev->dev,
461 "%s : timeout\n", __func__);
462 retval = bytes_read ? bytes_read : -ETIMEDOUT;
463 goto exit;
464 }
465
466 if (signal_pending(current)) {
467 dev_dbg(&dev->udev->dev,
468 "%s : signal pending\n",
469 __func__);
470 retval = bytes_read ? bytes_read : -EINTR;
471 goto exit;
472 }
473 }
474 }
475 }
476
477 retval = bytes_read;
478 /* if the primary buffer is empty then use it */
479 spin_lock_irqsave(&dev->buflock, flags);
480 if (should_submit && dev->read_urb_finished) {
481 dev->read_urb_finished = 0;
482 spin_unlock_irqrestore(&dev->buflock, flags);
483 usb_fill_int_urb(dev->interrupt_in_urb, dev->udev,
484 usb_rcvintpipe(dev->udev,
485 dev->interrupt_in_endpoint->bEndpointAddress),
486 dev->interrupt_in_buffer,
487 usb_endpoint_maxp(dev->interrupt_in_endpoint),
488 adu_interrupt_in_callback,
489 dev,
490 dev->interrupt_in_endpoint->bInterval);
491 if (usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL) != 0)
492 dev->read_urb_finished = 1;
493 /* we ignore failure */
494 } else {
495 spin_unlock_irqrestore(&dev->buflock, flags);
496 }
497
498exit:
499 /* unlock the device */
500 mutex_unlock(&dev->mtx);
501
502 return retval;
503}
504
505static ssize_t adu_write(struct file *file, const __user char *buffer,
506 size_t count, loff_t *ppos)
507{
508 DECLARE_WAITQUEUE(waita, current);
509 struct adu_device *dev;
510 size_t bytes_written = 0;
511 size_t bytes_to_write;
512 size_t buffer_size;
513 unsigned long flags;
514 int retval;
515
516 dev = file->private_data;
517
518 retval = mutex_lock_interruptible(&dev->mtx);
519 if (retval)
520 goto exit_nolock;
521
522 /* verify that the device wasn't unplugged */
523 if (dev->disconnected) {
524 retval = -ENODEV;
525 pr_err("No device or device unplugged %d\n", retval);
526 goto exit;
527 }
528
529 /* verify that we actually have some data to write */
530 if (count == 0) {
531 dev_dbg(&dev->udev->dev, "%s : write request of 0 bytes\n",
532 __func__);
533 goto exit;
534 }
535
536 while (count > 0) {
537 add_wait_queue(&dev->write_wait, &waita);
538 set_current_state(TASK_INTERRUPTIBLE);
539 spin_lock_irqsave(&dev->buflock, flags);
540 if (!dev->out_urb_finished) {
541 spin_unlock_irqrestore(&dev->buflock, flags);
542
543 mutex_unlock(&dev->mtx);
544 if (signal_pending(current)) {
545 dev_dbg(&dev->udev->dev, "%s : interrupted\n",
546 __func__);
547 set_current_state(TASK_RUNNING);
548 retval = -EINTR;
549 goto exit_onqueue;
550 }
551 if (schedule_timeout(COMMAND_TIMEOUT) == 0) {
552 dev_dbg(&dev->udev->dev,
553 "%s - command timed out.\n", __func__);
554 retval = -ETIMEDOUT;
555 goto exit_onqueue;
556 }
557 remove_wait_queue(&dev->write_wait, &waita);
558 retval = mutex_lock_interruptible(&dev->mtx);
559 if (retval) {
560 retval = bytes_written ? bytes_written : retval;
561 goto exit_nolock;
562 }
563
564 dev_dbg(&dev->udev->dev,
565 "%s : in progress, count = %zd\n",
566 __func__, count);
567 } else {
568 spin_unlock_irqrestore(&dev->buflock, flags);
569 set_current_state(TASK_RUNNING);
570 remove_wait_queue(&dev->write_wait, &waita);
571 dev_dbg(&dev->udev->dev, "%s : sending, count = %zd\n",
572 __func__, count);
573
574 /* write the data into interrupt_out_buffer from userspace */
575 buffer_size = usb_endpoint_maxp(dev->interrupt_out_endpoint);
576 bytes_to_write = count > buffer_size ? buffer_size : count;
577 dev_dbg(&dev->udev->dev,
578 "%s : buffer_size = %zd, count = %zd, bytes_to_write = %zd\n",
579 __func__, buffer_size, count, bytes_to_write);
580
581 if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write) != 0) {
582 retval = -EFAULT;
583 goto exit;
584 }
585
586 /* send off the urb */
587 usb_fill_int_urb(
588 dev->interrupt_out_urb,
589 dev->udev,
590 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
591 dev->interrupt_out_buffer,
592 bytes_to_write,
593 adu_interrupt_out_callback,
594 dev,
595 dev->interrupt_out_endpoint->bInterval);
596 dev->interrupt_out_urb->actual_length = bytes_to_write;
597 dev->out_urb_finished = 0;
598 retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
599 if (retval < 0) {
600 dev->out_urb_finished = 1;
601 dev_err(&dev->udev->dev, "Couldn't submit "
602 "interrupt_out_urb %d\n", retval);
603 goto exit;
604 }
605
606 buffer += bytes_to_write;
607 count -= bytes_to_write;
608
609 bytes_written += bytes_to_write;
610 }
611 }
612 mutex_unlock(&dev->mtx);
613 return bytes_written;
614
615exit:
616 mutex_unlock(&dev->mtx);
617exit_nolock:
618 return retval;
619
620exit_onqueue:
621 remove_wait_queue(&dev->write_wait, &waita);
622 return retval;
623}
624
625/* file operations needed when we register this driver */
626static const struct file_operations adu_fops = {
627 .owner = THIS_MODULE,
628 .read = adu_read,
629 .write = adu_write,
630 .open = adu_open,
631 .release = adu_release,
632 .llseek = noop_llseek,
633};
634
635/*
636 * usb class driver info in order to get a minor number from the usb core,
637 * and to have the device registered with devfs and the driver core
638 */
639static struct usb_class_driver adu_class = {
640 .name = "usb/adutux%d",
641 .fops = &adu_fops,
642 .minor_base = ADU_MINOR_BASE,
643};
644
645/*
646 * adu_probe
647 *
648 * Called by the usb core when a new device is connected that it thinks
649 * this driver might be interested in.
650 */
651static int adu_probe(struct usb_interface *interface,
652 const struct usb_device_id *id)
653{
654 struct usb_device *udev = interface_to_usbdev(interface);
655 struct adu_device *dev = NULL;
656 int retval = -ENOMEM;
657 int in_end_size;
658 int out_end_size;
659 int res;
660
661 /* allocate memory for our device state and initialize it */
662 dev = kzalloc(sizeof(struct adu_device), GFP_KERNEL);
663 if (!dev)
664 return -ENOMEM;
665
666 mutex_init(&dev->mtx);
667 spin_lock_init(&dev->buflock);
668 dev->udev = usb_get_dev(udev);
669 init_waitqueue_head(&dev->read_wait);
670 init_waitqueue_head(&dev->write_wait);
671
672 res = usb_find_common_endpoints_reverse(interface->cur_altsetting,
673 NULL, NULL,
674 &dev->interrupt_in_endpoint,
675 &dev->interrupt_out_endpoint);
676 if (res) {
677 dev_err(&interface->dev, "interrupt endpoints not found\n");
678 retval = res;
679 goto error;
680 }
681
682 in_end_size = usb_endpoint_maxp(dev->interrupt_in_endpoint);
683 out_end_size = usb_endpoint_maxp(dev->interrupt_out_endpoint);
684
685 dev->read_buffer_primary = kmalloc((4 * in_end_size), GFP_KERNEL);
686 if (!dev->read_buffer_primary)
687 goto error;
688
689 /* debug code prime the buffer */
690 memset(dev->read_buffer_primary, 'a', in_end_size);
691 memset(dev->read_buffer_primary + in_end_size, 'b', in_end_size);
692 memset(dev->read_buffer_primary + (2 * in_end_size), 'c', in_end_size);
693 memset(dev->read_buffer_primary + (3 * in_end_size), 'd', in_end_size);
694
695 dev->read_buffer_secondary = kmalloc((4 * in_end_size), GFP_KERNEL);
696 if (!dev->read_buffer_secondary)
697 goto error;
698
699 /* debug code prime the buffer */
700 memset(dev->read_buffer_secondary, 'e', in_end_size);
701 memset(dev->read_buffer_secondary + in_end_size, 'f', in_end_size);
702 memset(dev->read_buffer_secondary + (2 * in_end_size), 'g', in_end_size);
703 memset(dev->read_buffer_secondary + (3 * in_end_size), 'h', in_end_size);
704
705 dev->interrupt_in_buffer = kmalloc(in_end_size, GFP_KERNEL);
706 if (!dev->interrupt_in_buffer)
707 goto error;
708
709 /* debug code prime the buffer */
710 memset(dev->interrupt_in_buffer, 'i', in_end_size);
711
712 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
713 if (!dev->interrupt_in_urb)
714 goto error;
715 dev->interrupt_out_buffer = kmalloc(out_end_size, GFP_KERNEL);
716 if (!dev->interrupt_out_buffer)
717 goto error;
718 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
719 if (!dev->interrupt_out_urb)
720 goto error;
721
722 if (!usb_string(udev, udev->descriptor.iSerialNumber, dev->serial_number,
723 sizeof(dev->serial_number))) {
724 dev_err(&interface->dev, "Could not retrieve serial number\n");
725 retval = -EIO;
726 goto error;
727 }
728 dev_dbg(&interface->dev,"serial_number=%s", dev->serial_number);
729
730 /* we can register the device now, as it is ready */
731 usb_set_intfdata(interface, dev);
732
733 retval = usb_register_dev(interface, &adu_class);
734
735 if (retval) {
736 /* something prevented us from registering this driver */
737 dev_err(&interface->dev, "Not able to get a minor for this device.\n");
738 usb_set_intfdata(interface, NULL);
739 goto error;
740 }
741
742 dev->minor = interface->minor;
743
744 /* let the user know what node this device is now attached to */
745 dev_info(&interface->dev, "ADU%d %s now attached to /dev/usb/adutux%d\n",
746 le16_to_cpu(udev->descriptor.idProduct), dev->serial_number,
747 (dev->minor - ADU_MINOR_BASE));
748
749 return 0;
750
751error:
752 adu_delete(dev);
753 return retval;
754}
755
756/*
757 * adu_disconnect
758 *
759 * Called by the usb core when the device is removed from the system.
760 */
761static void adu_disconnect(struct usb_interface *interface)
762{
763 struct adu_device *dev;
764
765 dev = usb_get_intfdata(interface);
766
767 usb_deregister_dev(interface, &adu_class);
768
769 usb_poison_urb(dev->interrupt_in_urb);
770 usb_poison_urb(dev->interrupt_out_urb);
771
772 mutex_lock(&adutux_mutex);
773 usb_set_intfdata(interface, NULL);
774
775 mutex_lock(&dev->mtx); /* not interruptible */
776 dev->disconnected = 1;
777 mutex_unlock(&dev->mtx);
778
779 /* if the device is not opened, then we clean up right now */
780 if (!dev->open_count)
781 adu_delete(dev);
782
783 mutex_unlock(&adutux_mutex);
784}
785
786/* usb specific object needed to register this driver with the usb subsystem */
787static struct usb_driver adu_driver = {
788 .name = "adutux",
789 .probe = adu_probe,
790 .disconnect = adu_disconnect,
791 .id_table = device_table,
792};
793
794module_usb_driver(adu_driver);
795
796MODULE_AUTHOR(DRIVER_AUTHOR);
797MODULE_DESCRIPTION(DRIVER_DESC);
798MODULE_LICENSE("GPL");
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * adutux - driver for ADU devices from Ontrak Control Systems
4 * This is an experimental driver. Use at your own risk.
5 * This driver is not supported by Ontrak Control Systems.
6 *
7 * Copyright (c) 2003 John Homppi (SCO, leave this notice here)
8 *
9 * derived from the Lego USB Tower driver 0.56:
10 * Copyright (c) 2003 David Glance <davidgsf@sourceforge.net>
11 * 2001 Juergen Stuber <stuber@loria.fr>
12 * that was derived from USB Skeleton driver - 0.5
13 * Copyright (c) 2001 Greg Kroah-Hartman (greg@kroah.com)
14 *
15 */
16
17#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18
19#include <linux/kernel.h>
20#include <linux/sched/signal.h>
21#include <linux/errno.h>
22#include <linux/slab.h>
23#include <linux/module.h>
24#include <linux/usb.h>
25#include <linux/mutex.h>
26#include <linux/uaccess.h>
27
28#define DRIVER_AUTHOR "John Homppi"
29#define DRIVER_DESC "adutux (see www.ontrak.net)"
30
31/* Define these values to match your device */
32#define ADU_VENDOR_ID 0x0a07
33#define ADU_PRODUCT_ID 0x0064
34
35/* table of devices that work with this driver */
36static const struct usb_device_id device_table[] = {
37 { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID) }, /* ADU100 */
38 { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+20) }, /* ADU120 */
39 { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+30) }, /* ADU130 */
40 { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+100) }, /* ADU200 */
41 { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+108) }, /* ADU208 */
42 { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+118) }, /* ADU218 */
43 { } /* Terminating entry */
44};
45
46MODULE_DEVICE_TABLE(usb, device_table);
47
48#ifdef CONFIG_USB_DYNAMIC_MINORS
49#define ADU_MINOR_BASE 0
50#else
51#define ADU_MINOR_BASE 67
52#endif
53
54/* we can have up to this number of device plugged in at once */
55#define MAX_DEVICES 16
56
57#define COMMAND_TIMEOUT (2*HZ)
58
59/*
60 * The locking scheme is a vanilla 3-lock:
61 * adu_device.buflock: A spinlock, covers what IRQs touch.
62 * adutux_mutex: A Static lock to cover open_count. It would also cover
63 * any globals, but we don't have them in 2.6.
64 * adu_device.mtx: A mutex to hold across sleepers like copy_from_user.
65 * It covers all of adu_device, except the open_count
66 * and what .buflock covers.
67 */
68
69/* Structure to hold all of our device specific stuff */
70struct adu_device {
71 struct mutex mtx;
72 struct usb_device *udev; /* save off the usb device pointer */
73 struct usb_interface *interface;
74 unsigned int minor; /* the starting minor number for this device */
75 char serial_number[8];
76
77 int open_count; /* number of times this port has been opened */
78 unsigned long disconnected:1;
79
80 char *read_buffer_primary;
81 int read_buffer_length;
82 char *read_buffer_secondary;
83 int secondary_head;
84 int secondary_tail;
85 spinlock_t buflock;
86
87 wait_queue_head_t read_wait;
88 wait_queue_head_t write_wait;
89
90 char *interrupt_in_buffer;
91 struct usb_endpoint_descriptor *interrupt_in_endpoint;
92 struct urb *interrupt_in_urb;
93 int read_urb_finished;
94
95 char *interrupt_out_buffer;
96 struct usb_endpoint_descriptor *interrupt_out_endpoint;
97 struct urb *interrupt_out_urb;
98 int out_urb_finished;
99};
100
101static DEFINE_MUTEX(adutux_mutex);
102
103static struct usb_driver adu_driver;
104
105static inline void adu_debug_data(struct device *dev, const char *function,
106 int size, const unsigned char *data)
107{
108 dev_dbg(dev, "%s - length = %d, data = %*ph\n",
109 function, size, size, data);
110}
111
112/*
113 * adu_abort_transfers
114 * aborts transfers and frees associated data structures
115 */
116static void adu_abort_transfers(struct adu_device *dev)
117{
118 unsigned long flags;
119
120 if (dev->disconnected)
121 return;
122
123 /* shutdown transfer */
124
125 /* XXX Anchor these instead */
126 spin_lock_irqsave(&dev->buflock, flags);
127 if (!dev->read_urb_finished) {
128 spin_unlock_irqrestore(&dev->buflock, flags);
129 usb_kill_urb(dev->interrupt_in_urb);
130 } else
131 spin_unlock_irqrestore(&dev->buflock, flags);
132
133 spin_lock_irqsave(&dev->buflock, flags);
134 if (!dev->out_urb_finished) {
135 spin_unlock_irqrestore(&dev->buflock, flags);
136 wait_event_timeout(dev->write_wait, dev->out_urb_finished,
137 COMMAND_TIMEOUT);
138 usb_kill_urb(dev->interrupt_out_urb);
139 } else
140 spin_unlock_irqrestore(&dev->buflock, flags);
141}
142
143static void adu_delete(struct adu_device *dev)
144{
145 /* free data structures */
146 usb_free_urb(dev->interrupt_in_urb);
147 usb_free_urb(dev->interrupt_out_urb);
148 kfree(dev->read_buffer_primary);
149 kfree(dev->read_buffer_secondary);
150 kfree(dev->interrupt_in_buffer);
151 kfree(dev->interrupt_out_buffer);
152 usb_put_dev(dev->udev);
153 kfree(dev);
154}
155
156static void adu_interrupt_in_callback(struct urb *urb)
157{
158 struct adu_device *dev = urb->context;
159 int status = urb->status;
160 unsigned long flags;
161
162 adu_debug_data(&dev->udev->dev, __func__,
163 urb->actual_length, urb->transfer_buffer);
164
165 spin_lock_irqsave(&dev->buflock, flags);
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_irqrestore(&dev->buflock, flags);
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 unsigned long flags;
206
207 adu_debug_data(&dev->udev->dev, __func__,
208 urb->actual_length, urb->transfer_buffer);
209
210 if (status != 0) {
211 if ((status != -ENOENT) &&
212 (status != -ESHUTDOWN) &&
213 (status != -ECONNRESET)) {
214 dev_dbg(&dev->udev->dev,
215 "%s :nonzero status received: %d\n", __func__,
216 status);
217 }
218 return;
219 }
220
221 spin_lock_irqsave(&dev->buflock, flags);
222 dev->out_urb_finished = 1;
223 wake_up(&dev->write_wait);
224 spin_unlock_irqrestore(&dev->buflock, flags);
225}
226
227static int adu_open(struct inode *inode, struct file *file)
228{
229 struct adu_device *dev = NULL;
230 struct usb_interface *interface;
231 int subminor;
232 int retval;
233
234 subminor = iminor(inode);
235
236 retval = mutex_lock_interruptible(&adutux_mutex);
237 if (retval)
238 goto exit_no_lock;
239
240 interface = usb_find_interface(&adu_driver, subminor);
241 if (!interface) {
242 pr_err("%s - error, can't find device for minor %d\n",
243 __func__, subminor);
244 retval = -ENODEV;
245 goto exit_no_device;
246 }
247
248 dev = usb_get_intfdata(interface);
249 if (!dev) {
250 retval = -ENODEV;
251 goto exit_no_device;
252 }
253
254 /* check that nobody else is using the device */
255 if (dev->open_count) {
256 retval = -EBUSY;
257 goto exit_no_device;
258 }
259
260 ++dev->open_count;
261 dev_dbg(&dev->udev->dev, "%s: open count %d\n", __func__,
262 dev->open_count);
263
264 /* save device in the file's private structure */
265 file->private_data = dev;
266
267 /* initialize in direction */
268 dev->read_buffer_length = 0;
269
270 /* fixup first read by having urb waiting for it */
271 usb_fill_int_urb(dev->interrupt_in_urb, dev->udev,
272 usb_rcvintpipe(dev->udev,
273 dev->interrupt_in_endpoint->bEndpointAddress),
274 dev->interrupt_in_buffer,
275 usb_endpoint_maxp(dev->interrupt_in_endpoint),
276 adu_interrupt_in_callback, dev,
277 dev->interrupt_in_endpoint->bInterval);
278 dev->read_urb_finished = 0;
279 if (usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL))
280 dev->read_urb_finished = 1;
281 /* we ignore failure */
282 /* end of fixup for first read */
283
284 /* initialize out direction */
285 dev->out_urb_finished = 1;
286
287 retval = 0;
288
289exit_no_device:
290 mutex_unlock(&adutux_mutex);
291exit_no_lock:
292 return retval;
293}
294
295static void adu_release_internal(struct adu_device *dev)
296{
297 /* decrement our usage count for the device */
298 --dev->open_count;
299 dev_dbg(&dev->udev->dev, "%s : open count %d\n", __func__,
300 dev->open_count);
301 if (dev->open_count <= 0) {
302 adu_abort_transfers(dev);
303 dev->open_count = 0;
304 }
305}
306
307static int adu_release(struct inode *inode, struct file *file)
308{
309 struct adu_device *dev;
310 int retval = 0;
311
312 if (file == NULL) {
313 retval = -ENODEV;
314 goto exit;
315 }
316
317 dev = file->private_data;
318 if (dev == NULL) {
319 retval = -ENODEV;
320 goto exit;
321 }
322
323 mutex_lock(&adutux_mutex); /* not interruptible */
324
325 if (dev->open_count <= 0) {
326 dev_dbg(&dev->udev->dev, "%s : device not opened\n", __func__);
327 retval = -ENODEV;
328 goto unlock;
329 }
330
331 adu_release_internal(dev);
332 if (dev->disconnected) {
333 /* the device was unplugged before the file was released */
334 if (!dev->open_count) /* ... and we're the last user */
335 adu_delete(dev);
336 }
337unlock:
338 mutex_unlock(&adutux_mutex);
339exit:
340 return retval;
341}
342
343static ssize_t adu_read(struct file *file, __user char *buffer, size_t count,
344 loff_t *ppos)
345{
346 struct adu_device *dev;
347 size_t bytes_read = 0;
348 size_t bytes_to_read = count;
349 int retval = 0;
350 int timeout = 0;
351 int should_submit = 0;
352 unsigned long flags;
353 DECLARE_WAITQUEUE(wait, current);
354
355 dev = file->private_data;
356 if (mutex_lock_interruptible(&dev->mtx))
357 return -ERESTARTSYS;
358
359 /* verify that the device wasn't unplugged */
360 if (dev->disconnected) {
361 retval = -ENODEV;
362 pr_err("No device or device unplugged %d\n", retval);
363 goto exit;
364 }
365
366 /* verify that some data was requested */
367 if (count == 0) {
368 dev_dbg(&dev->udev->dev, "%s : read request of 0 bytes\n",
369 __func__);
370 goto exit;
371 }
372
373 timeout = COMMAND_TIMEOUT;
374 dev_dbg(&dev->udev->dev, "%s : about to start looping\n", __func__);
375 while (bytes_to_read) {
376 size_t data_in_secondary = dev->secondary_tail - dev->secondary_head;
377 dev_dbg(&dev->udev->dev,
378 "%s : while, data_in_secondary=%zu, status=%d\n",
379 __func__, data_in_secondary,
380 dev->interrupt_in_urb->status);
381
382 if (data_in_secondary) {
383 /* drain secondary buffer */
384 size_t amount = min(bytes_to_read, data_in_secondary);
385 if (copy_to_user(buffer, dev->read_buffer_secondary+dev->secondary_head, amount)) {
386 retval = -EFAULT;
387 goto exit;
388 }
389 dev->secondary_head += amount;
390 bytes_read += amount;
391 bytes_to_read -= amount;
392 } else {
393 /* we check the primary buffer */
394 spin_lock_irqsave (&dev->buflock, flags);
395 if (dev->read_buffer_length) {
396 /* we secure access to the primary */
397 char *tmp;
398 dev_dbg(&dev->udev->dev,
399 "%s : swap, read_buffer_length = %d\n",
400 __func__, dev->read_buffer_length);
401 tmp = dev->read_buffer_secondary;
402 dev->read_buffer_secondary = dev->read_buffer_primary;
403 dev->read_buffer_primary = tmp;
404 dev->secondary_head = 0;
405 dev->secondary_tail = dev->read_buffer_length;
406 dev->read_buffer_length = 0;
407 spin_unlock_irqrestore(&dev->buflock, flags);
408 /* we have a free buffer so use it */
409 should_submit = 1;
410 } else {
411 /* even the primary was empty - we may need to do IO */
412 if (!dev->read_urb_finished) {
413 /* somebody is doing IO */
414 spin_unlock_irqrestore(&dev->buflock, flags);
415 dev_dbg(&dev->udev->dev,
416 "%s : submitted already\n",
417 __func__);
418 } else {
419 /* we must initiate input */
420 dev_dbg(&dev->udev->dev,
421 "%s : initiate input\n",
422 __func__);
423 dev->read_urb_finished = 0;
424 spin_unlock_irqrestore(&dev->buflock, flags);
425
426 usb_fill_int_urb(dev->interrupt_in_urb, dev->udev,
427 usb_rcvintpipe(dev->udev,
428 dev->interrupt_in_endpoint->bEndpointAddress),
429 dev->interrupt_in_buffer,
430 usb_endpoint_maxp(dev->interrupt_in_endpoint),
431 adu_interrupt_in_callback,
432 dev,
433 dev->interrupt_in_endpoint->bInterval);
434 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
435 if (retval) {
436 dev->read_urb_finished = 1;
437 if (retval == -ENOMEM) {
438 retval = bytes_read ? bytes_read : -ENOMEM;
439 }
440 dev_dbg(&dev->udev->dev,
441 "%s : submit failed\n",
442 __func__);
443 goto exit;
444 }
445 }
446
447 /* we wait for I/O to complete */
448 set_current_state(TASK_INTERRUPTIBLE);
449 add_wait_queue(&dev->read_wait, &wait);
450 spin_lock_irqsave(&dev->buflock, flags);
451 if (!dev->read_urb_finished) {
452 spin_unlock_irqrestore(&dev->buflock, flags);
453 timeout = schedule_timeout(COMMAND_TIMEOUT);
454 } else {
455 spin_unlock_irqrestore(&dev->buflock, flags);
456 set_current_state(TASK_RUNNING);
457 }
458 remove_wait_queue(&dev->read_wait, &wait);
459
460 if (timeout <= 0) {
461 dev_dbg(&dev->udev->dev,
462 "%s : timeout\n", __func__);
463 retval = bytes_read ? bytes_read : -ETIMEDOUT;
464 goto exit;
465 }
466
467 if (signal_pending(current)) {
468 dev_dbg(&dev->udev->dev,
469 "%s : signal pending\n",
470 __func__);
471 retval = bytes_read ? bytes_read : -EINTR;
472 goto exit;
473 }
474 }
475 }
476 }
477
478 retval = bytes_read;
479 /* if the primary buffer is empty then use it */
480 spin_lock_irqsave(&dev->buflock, flags);
481 if (should_submit && dev->read_urb_finished) {
482 dev->read_urb_finished = 0;
483 spin_unlock_irqrestore(&dev->buflock, flags);
484 usb_fill_int_urb(dev->interrupt_in_urb, dev->udev,
485 usb_rcvintpipe(dev->udev,
486 dev->interrupt_in_endpoint->bEndpointAddress),
487 dev->interrupt_in_buffer,
488 usb_endpoint_maxp(dev->interrupt_in_endpoint),
489 adu_interrupt_in_callback,
490 dev,
491 dev->interrupt_in_endpoint->bInterval);
492 if (usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL) != 0)
493 dev->read_urb_finished = 1;
494 /* we ignore failure */
495 } else {
496 spin_unlock_irqrestore(&dev->buflock, flags);
497 }
498
499exit:
500 /* unlock the device */
501 mutex_unlock(&dev->mtx);
502
503 return retval;
504}
505
506static ssize_t adu_write(struct file *file, const __user char *buffer,
507 size_t count, loff_t *ppos)
508{
509 DECLARE_WAITQUEUE(waita, current);
510 struct adu_device *dev;
511 size_t bytes_written = 0;
512 size_t bytes_to_write;
513 size_t buffer_size;
514 unsigned long flags;
515 int retval;
516
517 dev = file->private_data;
518
519 retval = mutex_lock_interruptible(&dev->mtx);
520 if (retval)
521 goto exit_nolock;
522
523 /* verify that the device wasn't unplugged */
524 if (dev->disconnected) {
525 retval = -ENODEV;
526 pr_err("No device or device unplugged %d\n", retval);
527 goto exit;
528 }
529
530 /* verify that we actually have some data to write */
531 if (count == 0) {
532 dev_dbg(&dev->udev->dev, "%s : write request of 0 bytes\n",
533 __func__);
534 goto exit;
535 }
536
537 while (count > 0) {
538 add_wait_queue(&dev->write_wait, &waita);
539 set_current_state(TASK_INTERRUPTIBLE);
540 spin_lock_irqsave(&dev->buflock, flags);
541 if (!dev->out_urb_finished) {
542 spin_unlock_irqrestore(&dev->buflock, flags);
543
544 mutex_unlock(&dev->mtx);
545 if (signal_pending(current)) {
546 dev_dbg(&dev->udev->dev, "%s : interrupted\n",
547 __func__);
548 set_current_state(TASK_RUNNING);
549 retval = -EINTR;
550 goto exit_onqueue;
551 }
552 if (schedule_timeout(COMMAND_TIMEOUT) == 0) {
553 dev_dbg(&dev->udev->dev,
554 "%s - command timed out.\n", __func__);
555 retval = -ETIMEDOUT;
556 goto exit_onqueue;
557 }
558 remove_wait_queue(&dev->write_wait, &waita);
559 retval = mutex_lock_interruptible(&dev->mtx);
560 if (retval) {
561 retval = bytes_written ? bytes_written : retval;
562 goto exit_nolock;
563 }
564
565 dev_dbg(&dev->udev->dev,
566 "%s : in progress, count = %zd\n",
567 __func__, count);
568 } else {
569 spin_unlock_irqrestore(&dev->buflock, flags);
570 set_current_state(TASK_RUNNING);
571 remove_wait_queue(&dev->write_wait, &waita);
572 dev_dbg(&dev->udev->dev, "%s : sending, count = %zd\n",
573 __func__, count);
574
575 /* write the data into interrupt_out_buffer from userspace */
576 buffer_size = usb_endpoint_maxp(dev->interrupt_out_endpoint);
577 bytes_to_write = count > buffer_size ? buffer_size : count;
578 dev_dbg(&dev->udev->dev,
579 "%s : buffer_size = %zd, count = %zd, bytes_to_write = %zd\n",
580 __func__, buffer_size, count, bytes_to_write);
581
582 if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write) != 0) {
583 retval = -EFAULT;
584 goto exit;
585 }
586
587 /* send off the urb */
588 usb_fill_int_urb(
589 dev->interrupt_out_urb,
590 dev->udev,
591 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
592 dev->interrupt_out_buffer,
593 bytes_to_write,
594 adu_interrupt_out_callback,
595 dev,
596 dev->interrupt_out_endpoint->bInterval);
597 dev->interrupt_out_urb->actual_length = bytes_to_write;
598 dev->out_urb_finished = 0;
599 retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
600 if (retval < 0) {
601 dev->out_urb_finished = 1;
602 dev_err(&dev->udev->dev, "Couldn't submit "
603 "interrupt_out_urb %d\n", retval);
604 goto exit;
605 }
606
607 buffer += bytes_to_write;
608 count -= bytes_to_write;
609
610 bytes_written += bytes_to_write;
611 }
612 }
613 mutex_unlock(&dev->mtx);
614 return bytes_written;
615
616exit:
617 mutex_unlock(&dev->mtx);
618exit_nolock:
619 return retval;
620
621exit_onqueue:
622 remove_wait_queue(&dev->write_wait, &waita);
623 return retval;
624}
625
626/* file operations needed when we register this driver */
627static const struct file_operations adu_fops = {
628 .owner = THIS_MODULE,
629 .read = adu_read,
630 .write = adu_write,
631 .open = adu_open,
632 .release = adu_release,
633 .llseek = noop_llseek,
634};
635
636/*
637 * usb class driver info in order to get a minor number from the usb core,
638 * and to have the device registered with devfs and the driver core
639 */
640static struct usb_class_driver adu_class = {
641 .name = "usb/adutux%d",
642 .fops = &adu_fops,
643 .minor_base = ADU_MINOR_BASE,
644};
645
646/*
647 * adu_probe
648 *
649 * Called by the usb core when a new device is connected that it thinks
650 * this driver might be interested in.
651 */
652static int adu_probe(struct usb_interface *interface,
653 const struct usb_device_id *id)
654{
655 struct usb_device *udev = interface_to_usbdev(interface);
656 struct adu_device *dev = NULL;
657 int retval = -ENOMEM;
658 int in_end_size;
659 int out_end_size;
660 int res;
661
662 /* allocate memory for our device state and initialize it */
663 dev = kzalloc(sizeof(struct adu_device), GFP_KERNEL);
664 if (!dev)
665 return -ENOMEM;
666
667 mutex_init(&dev->mtx);
668 spin_lock_init(&dev->buflock);
669 dev->udev = usb_get_dev(udev);
670 init_waitqueue_head(&dev->read_wait);
671 init_waitqueue_head(&dev->write_wait);
672
673 res = usb_find_common_endpoints_reverse(interface->cur_altsetting,
674 NULL, NULL,
675 &dev->interrupt_in_endpoint,
676 &dev->interrupt_out_endpoint);
677 if (res) {
678 dev_err(&interface->dev, "interrupt endpoints not found\n");
679 retval = res;
680 goto error;
681 }
682
683 in_end_size = usb_endpoint_maxp(dev->interrupt_in_endpoint);
684 out_end_size = usb_endpoint_maxp(dev->interrupt_out_endpoint);
685
686 dev->read_buffer_primary = kmalloc((4 * in_end_size), GFP_KERNEL);
687 if (!dev->read_buffer_primary)
688 goto error;
689
690 /* debug code prime the buffer */
691 memset(dev->read_buffer_primary, 'a', in_end_size);
692 memset(dev->read_buffer_primary + in_end_size, 'b', in_end_size);
693 memset(dev->read_buffer_primary + (2 * in_end_size), 'c', in_end_size);
694 memset(dev->read_buffer_primary + (3 * in_end_size), 'd', in_end_size);
695
696 dev->read_buffer_secondary = kmalloc((4 * in_end_size), GFP_KERNEL);
697 if (!dev->read_buffer_secondary)
698 goto error;
699
700 /* debug code prime the buffer */
701 memset(dev->read_buffer_secondary, 'e', in_end_size);
702 memset(dev->read_buffer_secondary + in_end_size, 'f', in_end_size);
703 memset(dev->read_buffer_secondary + (2 * in_end_size), 'g', in_end_size);
704 memset(dev->read_buffer_secondary + (3 * in_end_size), 'h', in_end_size);
705
706 dev->interrupt_in_buffer = kmalloc(in_end_size, GFP_KERNEL);
707 if (!dev->interrupt_in_buffer)
708 goto error;
709
710 /* debug code prime the buffer */
711 memset(dev->interrupt_in_buffer, 'i', in_end_size);
712
713 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
714 if (!dev->interrupt_in_urb)
715 goto error;
716 dev->interrupt_out_buffer = kmalloc(out_end_size, GFP_KERNEL);
717 if (!dev->interrupt_out_buffer)
718 goto error;
719 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
720 if (!dev->interrupt_out_urb)
721 goto error;
722
723 if (!usb_string(udev, udev->descriptor.iSerialNumber, dev->serial_number,
724 sizeof(dev->serial_number))) {
725 dev_err(&interface->dev, "Could not retrieve serial number\n");
726 retval = -EIO;
727 goto error;
728 }
729 dev_dbg(&interface->dev, "serial_number=%s", dev->serial_number);
730
731 /* we can register the device now, as it is ready */
732 usb_set_intfdata(interface, dev);
733
734 retval = usb_register_dev(interface, &adu_class);
735
736 if (retval) {
737 /* something prevented us from registering this driver */
738 dev_err(&interface->dev, "Not able to get a minor for this device.\n");
739 usb_set_intfdata(interface, NULL);
740 goto error;
741 }
742
743 dev->minor = interface->minor;
744
745 /* let the user know what node this device is now attached to */
746 dev_info(&interface->dev, "ADU%d %s now attached to /dev/usb/adutux%d\n",
747 le16_to_cpu(udev->descriptor.idProduct), dev->serial_number,
748 (dev->minor - ADU_MINOR_BASE));
749
750 return 0;
751
752error:
753 adu_delete(dev);
754 return retval;
755}
756
757/*
758 * adu_disconnect
759 *
760 * Called by the usb core when the device is removed from the system.
761 */
762static void adu_disconnect(struct usb_interface *interface)
763{
764 struct adu_device *dev;
765
766 dev = usb_get_intfdata(interface);
767
768 usb_deregister_dev(interface, &adu_class);
769
770 usb_poison_urb(dev->interrupt_in_urb);
771 usb_poison_urb(dev->interrupt_out_urb);
772
773 mutex_lock(&adutux_mutex);
774 usb_set_intfdata(interface, NULL);
775
776 mutex_lock(&dev->mtx); /* not interruptible */
777 dev->disconnected = 1;
778 mutex_unlock(&dev->mtx);
779
780 /* if the device is not opened, then we clean up right now */
781 if (!dev->open_count)
782 adu_delete(dev);
783
784 mutex_unlock(&adutux_mutex);
785}
786
787/* usb specific object needed to register this driver with the usb subsystem */
788static struct usb_driver adu_driver = {
789 .name = "adutux",
790 .probe = adu_probe,
791 .disconnect = adu_disconnect,
792 .id_table = device_table,
793};
794
795module_usb_driver(adu_driver);
796
797MODULE_AUTHOR(DRIVER_AUTHOR);
798MODULE_DESCRIPTION(DRIVER_DESC);
799MODULE_LICENSE("GPL");