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1/*
2 * adutux - driver for ADU devices from Ontrak Control Systems
3 * This is an experimental driver. Use at your own risk.
4 * This driver is not supported by Ontrak Control Systems.
5 *
6 * Copyright (c) 2003 John Homppi (SCO, leave this notice here)
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License as
10 * published by the Free Software Foundation; either version 2 of
11 * the License, or (at your option) any later version.
12 *
13 * derived from the Lego USB Tower driver 0.56:
14 * Copyright (c) 2003 David Glance <davidgsf@sourceforge.net>
15 * 2001 Juergen Stuber <stuber@loria.fr>
16 * that was derived from USB Skeleton driver - 0.5
17 * Copyright (c) 2001 Greg Kroah-Hartman (greg@kroah.com)
18 *
19 */
20
21#include <linux/kernel.h>
22#include <linux/errno.h>
23#include <linux/init.h>
24#include <linux/slab.h>
25#include <linux/module.h>
26#include <linux/usb.h>
27#include <linux/mutex.h>
28#include <asm/uaccess.h>
29
30#ifdef CONFIG_USB_DEBUG
31static int debug = 5;
32#else
33static int debug = 1;
34#endif
35
36/* Use our own dbg macro */
37#undef dbg
38#define dbg(lvl, format, arg...) \
39do { \
40 if (debug >= lvl) \
41 printk(KERN_DEBUG "%s: " format "\n", __FILE__, ##arg); \
42} while (0)
43
44
45/* Version Information */
46#define DRIVER_VERSION "v0.0.13"
47#define DRIVER_AUTHOR "John Homppi"
48#define DRIVER_DESC "adutux (see www.ontrak.net)"
49
50/* Module parameters */
51module_param(debug, int, S_IRUGO | S_IWUSR);
52MODULE_PARM_DESC(debug, "Debug enabled or not");
53
54/* Define these values to match your device */
55#define ADU_VENDOR_ID 0x0a07
56#define ADU_PRODUCT_ID 0x0064
57
58/* table of devices that work with this driver */
59static const struct usb_device_id device_table[] = {
60 { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID) }, /* ADU100 */
61 { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+20) }, /* ADU120 */
62 { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+30) }, /* ADU130 */
63 { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+100) }, /* ADU200 */
64 { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+108) }, /* ADU208 */
65 { USB_DEVICE(ADU_VENDOR_ID, ADU_PRODUCT_ID+118) }, /* ADU218 */
66 { }/* Terminating entry */
67};
68
69MODULE_DEVICE_TABLE(usb, device_table);
70
71#ifdef CONFIG_USB_DYNAMIC_MINORS
72#define ADU_MINOR_BASE 0
73#else
74#define ADU_MINOR_BASE 67
75#endif
76
77/* we can have up to this number of device plugged in at once */
78#define MAX_DEVICES 16
79
80#define COMMAND_TIMEOUT (2*HZ) /* 60 second timeout for a command */
81
82/*
83 * The locking scheme is a vanilla 3-lock:
84 * adu_device.buflock: A spinlock, covers what IRQs touch.
85 * adutux_mutex: A Static lock to cover open_count. It would also cover
86 * any globals, but we don't have them in 2.6.
87 * adu_device.mtx: A mutex to hold across sleepers like copy_from_user.
88 * It covers all of adu_device, except the open_count
89 * and what .buflock covers.
90 */
91
92/* Structure to hold all of our device specific stuff */
93struct adu_device {
94 struct mutex mtx;
95 struct usb_device* udev; /* save off the usb device pointer */
96 struct usb_interface* interface;
97 unsigned int minor; /* the starting minor number for this device */
98 char serial_number[8];
99
100 int open_count; /* number of times this port has been opened */
101
102 char* read_buffer_primary;
103 int read_buffer_length;
104 char* read_buffer_secondary;
105 int secondary_head;
106 int secondary_tail;
107 spinlock_t buflock;
108
109 wait_queue_head_t read_wait;
110 wait_queue_head_t write_wait;
111
112 char* interrupt_in_buffer;
113 struct usb_endpoint_descriptor* interrupt_in_endpoint;
114 struct urb* interrupt_in_urb;
115 int read_urb_finished;
116
117 char* interrupt_out_buffer;
118 struct usb_endpoint_descriptor* interrupt_out_endpoint;
119 struct urb* interrupt_out_urb;
120 int out_urb_finished;
121};
122
123static DEFINE_MUTEX(adutux_mutex);
124
125static struct usb_driver adu_driver;
126
127static void adu_debug_data(int level, const char *function, int size,
128 const unsigned char *data)
129{
130 int i;
131
132 if (debug < level)
133 return;
134
135 printk(KERN_DEBUG "%s: %s - length = %d, data = ",
136 __FILE__, function, size);
137 for (i = 0; i < size; ++i)
138 printk("%.2x ", data[i]);
139 printk("\n");
140}
141
142/**
143 * adu_abort_transfers
144 * aborts transfers and frees associated data structures
145 */
146static void adu_abort_transfers(struct adu_device *dev)
147{
148 unsigned long flags;
149
150 dbg(2," %s : enter", __func__);
151
152 if (dev->udev == NULL) {
153 dbg(1," %s : udev is null", __func__);
154 goto exit;
155 }
156
157 /* shutdown transfer */
158
159 /* XXX Anchor these instead */
160 spin_lock_irqsave(&dev->buflock, flags);
161 if (!dev->read_urb_finished) {
162 spin_unlock_irqrestore(&dev->buflock, flags);
163 usb_kill_urb(dev->interrupt_in_urb);
164 } else
165 spin_unlock_irqrestore(&dev->buflock, flags);
166
167 spin_lock_irqsave(&dev->buflock, flags);
168 if (!dev->out_urb_finished) {
169 spin_unlock_irqrestore(&dev->buflock, flags);
170 usb_kill_urb(dev->interrupt_out_urb);
171 } else
172 spin_unlock_irqrestore(&dev->buflock, flags);
173
174exit:
175 dbg(2," %s : leave", __func__);
176}
177
178static void adu_delete(struct adu_device *dev)
179{
180 dbg(2, "%s enter", __func__);
181
182 /* free data structures */
183 usb_free_urb(dev->interrupt_in_urb);
184 usb_free_urb(dev->interrupt_out_urb);
185 kfree(dev->read_buffer_primary);
186 kfree(dev->read_buffer_secondary);
187 kfree(dev->interrupt_in_buffer);
188 kfree(dev->interrupt_out_buffer);
189 kfree(dev);
190
191 dbg(2, "%s : leave", __func__);
192}
193
194static void adu_interrupt_in_callback(struct urb *urb)
195{
196 struct adu_device *dev = urb->context;
197 int status = urb->status;
198
199 dbg(4," %s : enter, status %d", __func__, status);
200 adu_debug_data(5, __func__, urb->actual_length,
201 urb->transfer_buffer);
202
203 spin_lock(&dev->buflock);
204
205 if (status != 0) {
206 if ((status != -ENOENT) && (status != -ECONNRESET) &&
207 (status != -ESHUTDOWN)) {
208 dbg(1," %s : nonzero status received: %d",
209 __func__, status);
210 }
211 goto exit;
212 }
213
214 if (urb->actual_length > 0 && dev->interrupt_in_buffer[0] != 0x00) {
215 if (dev->read_buffer_length <
216 (4 * le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize)) -
217 (urb->actual_length)) {
218 memcpy (dev->read_buffer_primary +
219 dev->read_buffer_length,
220 dev->interrupt_in_buffer, urb->actual_length);
221
222 dev->read_buffer_length += urb->actual_length;
223 dbg(2," %s reading %d ", __func__,
224 urb->actual_length);
225 } else {
226 dbg(1," %s : read_buffer overflow", __func__);
227 }
228 }
229
230exit:
231 dev->read_urb_finished = 1;
232 spin_unlock(&dev->buflock);
233 /* always wake up so we recover from errors */
234 wake_up_interruptible(&dev->read_wait);
235 adu_debug_data(5, __func__, urb->actual_length,
236 urb->transfer_buffer);
237 dbg(4," %s : leave, status %d", __func__, status);
238}
239
240static void adu_interrupt_out_callback(struct urb *urb)
241{
242 struct adu_device *dev = urb->context;
243 int status = urb->status;
244
245 dbg(4," %s : enter, status %d", __func__, status);
246 adu_debug_data(5,__func__, urb->actual_length, urb->transfer_buffer);
247
248 if (status != 0) {
249 if ((status != -ENOENT) &&
250 (status != -ECONNRESET)) {
251 dbg(1, " %s :nonzero status received: %d",
252 __func__, status);
253 }
254 goto exit;
255 }
256
257 spin_lock(&dev->buflock);
258 dev->out_urb_finished = 1;
259 wake_up(&dev->write_wait);
260 spin_unlock(&dev->buflock);
261exit:
262
263 adu_debug_data(5, __func__, urb->actual_length,
264 urb->transfer_buffer);
265 dbg(4," %s : leave, status %d", __func__, status);
266}
267
268static int adu_open(struct inode *inode, struct file *file)
269{
270 struct adu_device *dev = NULL;
271 struct usb_interface *interface;
272 int subminor;
273 int retval;
274
275 dbg(2,"%s : enter", __func__);
276
277 subminor = iminor(inode);
278
279 if ((retval = mutex_lock_interruptible(&adutux_mutex))) {
280 dbg(2, "%s : mutex lock failed", __func__);
281 goto exit_no_lock;
282 }
283
284 interface = usb_find_interface(&adu_driver, subminor);
285 if (!interface) {
286 printk(KERN_ERR "adutux: %s - error, can't find device for "
287 "minor %d\n", __func__, subminor);
288 retval = -ENODEV;
289 goto exit_no_device;
290 }
291
292 dev = usb_get_intfdata(interface);
293 if (!dev || !dev->udev) {
294 retval = -ENODEV;
295 goto exit_no_device;
296 }
297
298 /* check that nobody else is using the device */
299 if (dev->open_count) {
300 retval = -EBUSY;
301 goto exit_no_device;
302 }
303
304 ++dev->open_count;
305 dbg(2,"%s : open count %d", __func__, dev->open_count);
306
307 /* save device in the file's private structure */
308 file->private_data = dev;
309
310 /* initialize in direction */
311 dev->read_buffer_length = 0;
312
313 /* fixup first read by having urb waiting for it */
314 usb_fill_int_urb(dev->interrupt_in_urb,dev->udev,
315 usb_rcvintpipe(dev->udev,
316 dev->interrupt_in_endpoint->bEndpointAddress),
317 dev->interrupt_in_buffer,
318 le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
319 adu_interrupt_in_callback, dev,
320 dev->interrupt_in_endpoint->bInterval);
321 dev->read_urb_finished = 0;
322 if (usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL))
323 dev->read_urb_finished = 1;
324 /* we ignore failure */
325 /* end of fixup for first read */
326
327 /* initialize out direction */
328 dev->out_urb_finished = 1;
329
330 retval = 0;
331
332exit_no_device:
333 mutex_unlock(&adutux_mutex);
334exit_no_lock:
335 dbg(2,"%s : leave, return value %d ", __func__, retval);
336 return retval;
337}
338
339static void adu_release_internal(struct adu_device *dev)
340{
341 dbg(2," %s : enter", __func__);
342
343 /* decrement our usage count for the device */
344 --dev->open_count;
345 dbg(2," %s : open count %d", __func__, dev->open_count);
346 if (dev->open_count <= 0) {
347 adu_abort_transfers(dev);
348 dev->open_count = 0;
349 }
350
351 dbg(2," %s : leave", __func__);
352}
353
354static int adu_release(struct inode *inode, struct file *file)
355{
356 struct adu_device *dev;
357 int retval = 0;
358
359 dbg(2," %s : enter", __func__);
360
361 if (file == NULL) {
362 dbg(1," %s : file is NULL", __func__);
363 retval = -ENODEV;
364 goto exit;
365 }
366
367 dev = file->private_data;
368 if (dev == NULL) {
369 dbg(1," %s : object is NULL", __func__);
370 retval = -ENODEV;
371 goto exit;
372 }
373
374 mutex_lock(&adutux_mutex); /* not interruptible */
375
376 if (dev->open_count <= 0) {
377 dbg(1," %s : device not opened", __func__);
378 retval = -ENODEV;
379 goto unlock;
380 }
381
382 adu_release_internal(dev);
383 if (dev->udev == NULL) {
384 /* the device was unplugged before the file was released */
385 if (!dev->open_count) /* ... and we're the last user */
386 adu_delete(dev);
387 }
388unlock:
389 mutex_unlock(&adutux_mutex);
390exit:
391 dbg(2," %s : leave, return value %d", __func__, retval);
392 return retval;
393}
394
395static ssize_t adu_read(struct file *file, __user char *buffer, size_t count,
396 loff_t *ppos)
397{
398 struct adu_device *dev;
399 size_t bytes_read = 0;
400 size_t bytes_to_read = count;
401 int i;
402 int retval = 0;
403 int timeout = 0;
404 int should_submit = 0;
405 unsigned long flags;
406 DECLARE_WAITQUEUE(wait, current);
407
408 dbg(2," %s : enter, count = %Zd, file=%p", __func__, count, file);
409
410 dev = file->private_data;
411 dbg(2," %s : dev=%p", __func__, dev);
412
413 if (mutex_lock_interruptible(&dev->mtx))
414 return -ERESTARTSYS;
415
416 /* verify that the device wasn't unplugged */
417 if (dev->udev == NULL) {
418 retval = -ENODEV;
419 printk(KERN_ERR "adutux: No device or device unplugged %d\n",
420 retval);
421 goto exit;
422 }
423
424 /* verify that some data was requested */
425 if (count == 0) {
426 dbg(1," %s : read request of 0 bytes", __func__);
427 goto exit;
428 }
429
430 timeout = COMMAND_TIMEOUT;
431 dbg(2," %s : about to start looping", __func__);
432 while (bytes_to_read) {
433 int data_in_secondary = dev->secondary_tail - dev->secondary_head;
434 dbg(2," %s : while, data_in_secondary=%d, status=%d",
435 __func__, data_in_secondary,
436 dev->interrupt_in_urb->status);
437
438 if (data_in_secondary) {
439 /* drain secondary buffer */
440 int amount = bytes_to_read < data_in_secondary ? bytes_to_read : data_in_secondary;
441 i = copy_to_user(buffer, dev->read_buffer_secondary+dev->secondary_head, amount);
442 if (i) {
443 retval = -EFAULT;
444 goto exit;
445 }
446 dev->secondary_head += (amount - i);
447 bytes_read += (amount - i);
448 bytes_to_read -= (amount - i);
449 if (i) {
450 retval = bytes_read ? bytes_read : -EFAULT;
451 goto exit;
452 }
453 } else {
454 /* we check the primary buffer */
455 spin_lock_irqsave (&dev->buflock, flags);
456 if (dev->read_buffer_length) {
457 /* we secure access to the primary */
458 char *tmp;
459 dbg(2," %s : swap, read_buffer_length = %d",
460 __func__, dev->read_buffer_length);
461 tmp = dev->read_buffer_secondary;
462 dev->read_buffer_secondary = dev->read_buffer_primary;
463 dev->read_buffer_primary = tmp;
464 dev->secondary_head = 0;
465 dev->secondary_tail = dev->read_buffer_length;
466 dev->read_buffer_length = 0;
467 spin_unlock_irqrestore(&dev->buflock, flags);
468 /* we have a free buffer so use it */
469 should_submit = 1;
470 } else {
471 /* even the primary was empty - we may need to do IO */
472 if (!dev->read_urb_finished) {
473 /* somebody is doing IO */
474 spin_unlock_irqrestore(&dev->buflock, flags);
475 dbg(2," %s : submitted already", __func__);
476 } else {
477 /* we must initiate input */
478 dbg(2," %s : initiate input", __func__);
479 dev->read_urb_finished = 0;
480 spin_unlock_irqrestore(&dev->buflock, flags);
481
482 usb_fill_int_urb(dev->interrupt_in_urb,dev->udev,
483 usb_rcvintpipe(dev->udev,
484 dev->interrupt_in_endpoint->bEndpointAddress),
485 dev->interrupt_in_buffer,
486 le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
487 adu_interrupt_in_callback,
488 dev,
489 dev->interrupt_in_endpoint->bInterval);
490 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
491 if (retval) {
492 dev->read_urb_finished = 1;
493 if (retval == -ENOMEM) {
494 retval = bytes_read ? bytes_read : -ENOMEM;
495 }
496 dbg(2," %s : submit failed", __func__);
497 goto exit;
498 }
499 }
500
501 /* we wait for I/O to complete */
502 set_current_state(TASK_INTERRUPTIBLE);
503 add_wait_queue(&dev->read_wait, &wait);
504 spin_lock_irqsave(&dev->buflock, flags);
505 if (!dev->read_urb_finished) {
506 spin_unlock_irqrestore(&dev->buflock, flags);
507 timeout = schedule_timeout(COMMAND_TIMEOUT);
508 } else {
509 spin_unlock_irqrestore(&dev->buflock, flags);
510 set_current_state(TASK_RUNNING);
511 }
512 remove_wait_queue(&dev->read_wait, &wait);
513
514 if (timeout <= 0) {
515 dbg(2," %s : timeout", __func__);
516 retval = bytes_read ? bytes_read : -ETIMEDOUT;
517 goto exit;
518 }
519
520 if (signal_pending(current)) {
521 dbg(2," %s : signal pending", __func__);
522 retval = bytes_read ? bytes_read : -EINTR;
523 goto exit;
524 }
525 }
526 }
527 }
528
529 retval = bytes_read;
530 /* if the primary buffer is empty then use it */
531 spin_lock_irqsave(&dev->buflock, flags);
532 if (should_submit && dev->read_urb_finished) {
533 dev->read_urb_finished = 0;
534 spin_unlock_irqrestore(&dev->buflock, flags);
535 usb_fill_int_urb(dev->interrupt_in_urb,dev->udev,
536 usb_rcvintpipe(dev->udev,
537 dev->interrupt_in_endpoint->bEndpointAddress),
538 dev->interrupt_in_buffer,
539 le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize),
540 adu_interrupt_in_callback,
541 dev,
542 dev->interrupt_in_endpoint->bInterval);
543 if (usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL) != 0)
544 dev->read_urb_finished = 1;
545 /* we ignore failure */
546 } else {
547 spin_unlock_irqrestore(&dev->buflock, flags);
548 }
549
550exit:
551 /* unlock the device */
552 mutex_unlock(&dev->mtx);
553
554 dbg(2," %s : leave, return value %d", __func__, retval);
555 return retval;
556}
557
558static ssize_t adu_write(struct file *file, const __user char *buffer,
559 size_t count, loff_t *ppos)
560{
561 DECLARE_WAITQUEUE(waita, current);
562 struct adu_device *dev;
563 size_t bytes_written = 0;
564 size_t bytes_to_write;
565 size_t buffer_size;
566 unsigned long flags;
567 int retval;
568
569 dbg(2," %s : enter, count = %Zd", __func__, count);
570
571 dev = file->private_data;
572
573 retval = mutex_lock_interruptible(&dev->mtx);
574 if (retval)
575 goto exit_nolock;
576
577 /* verify that the device wasn't unplugged */
578 if (dev->udev == NULL) {
579 retval = -ENODEV;
580 printk(KERN_ERR "adutux: No device or device unplugged %d\n",
581 retval);
582 goto exit;
583 }
584
585 /* verify that we actually have some data to write */
586 if (count == 0) {
587 dbg(1," %s : write request of 0 bytes", __func__);
588 goto exit;
589 }
590
591 while (count > 0) {
592 add_wait_queue(&dev->write_wait, &waita);
593 set_current_state(TASK_INTERRUPTIBLE);
594 spin_lock_irqsave(&dev->buflock, flags);
595 if (!dev->out_urb_finished) {
596 spin_unlock_irqrestore(&dev->buflock, flags);
597
598 mutex_unlock(&dev->mtx);
599 if (signal_pending(current)) {
600 dbg(1," %s : interrupted", __func__);
601 set_current_state(TASK_RUNNING);
602 retval = -EINTR;
603 goto exit_onqueue;
604 }
605 if (schedule_timeout(COMMAND_TIMEOUT) == 0) {
606 dbg(1, "%s - command timed out.", __func__);
607 retval = -ETIMEDOUT;
608 goto exit_onqueue;
609 }
610 remove_wait_queue(&dev->write_wait, &waita);
611 retval = mutex_lock_interruptible(&dev->mtx);
612 if (retval) {
613 retval = bytes_written ? bytes_written : retval;
614 goto exit_nolock;
615 }
616
617 dbg(4," %s : in progress, count = %Zd", __func__, count);
618 } else {
619 spin_unlock_irqrestore(&dev->buflock, flags);
620 set_current_state(TASK_RUNNING);
621 remove_wait_queue(&dev->write_wait, &waita);
622 dbg(4," %s : sending, count = %Zd", __func__, count);
623
624 /* write the data into interrupt_out_buffer from userspace */
625 buffer_size = le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize);
626 bytes_to_write = count > buffer_size ? buffer_size : count;
627 dbg(4," %s : buffer_size = %Zd, count = %Zd, bytes_to_write = %Zd",
628 __func__, buffer_size, count, bytes_to_write);
629
630 if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write) != 0) {
631 retval = -EFAULT;
632 goto exit;
633 }
634
635 /* send off the urb */
636 usb_fill_int_urb(
637 dev->interrupt_out_urb,
638 dev->udev,
639 usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress),
640 dev->interrupt_out_buffer,
641 bytes_to_write,
642 adu_interrupt_out_callback,
643 dev,
644 dev->interrupt_out_endpoint->bInterval);
645 dev->interrupt_out_urb->actual_length = bytes_to_write;
646 dev->out_urb_finished = 0;
647 retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
648 if (retval < 0) {
649 dev->out_urb_finished = 1;
650 dev_err(&dev->udev->dev, "Couldn't submit "
651 "interrupt_out_urb %d\n", retval);
652 goto exit;
653 }
654
655 buffer += bytes_to_write;
656 count -= bytes_to_write;
657
658 bytes_written += bytes_to_write;
659 }
660 }
661 mutex_unlock(&dev->mtx);
662 return bytes_written;
663
664exit:
665 mutex_unlock(&dev->mtx);
666exit_nolock:
667 dbg(2," %s : leave, return value %d", __func__, retval);
668 return retval;
669
670exit_onqueue:
671 remove_wait_queue(&dev->write_wait, &waita);
672 return retval;
673}
674
675/* file operations needed when we register this driver */
676static const struct file_operations adu_fops = {
677 .owner = THIS_MODULE,
678 .read = adu_read,
679 .write = adu_write,
680 .open = adu_open,
681 .release = adu_release,
682 .llseek = noop_llseek,
683};
684
685/*
686 * usb class driver info in order to get a minor number from the usb core,
687 * and to have the device registered with devfs and the driver core
688 */
689static struct usb_class_driver adu_class = {
690 .name = "usb/adutux%d",
691 .fops = &adu_fops,
692 .minor_base = ADU_MINOR_BASE,
693};
694
695/**
696 * adu_probe
697 *
698 * Called by the usb core when a new device is connected that it thinks
699 * this driver might be interested in.
700 */
701static int adu_probe(struct usb_interface *interface,
702 const struct usb_device_id *id)
703{
704 struct usb_device *udev = interface_to_usbdev(interface);
705 struct adu_device *dev = NULL;
706 struct usb_host_interface *iface_desc;
707 struct usb_endpoint_descriptor *endpoint;
708 int retval = -ENODEV;
709 int in_end_size;
710 int out_end_size;
711 int i;
712
713 dbg(2," %s : enter", __func__);
714
715 if (udev == NULL) {
716 dev_err(&interface->dev, "udev is NULL.\n");
717 goto exit;
718 }
719
720 /* allocate memory for our device state and initialize it */
721 dev = kzalloc(sizeof(struct adu_device), GFP_KERNEL);
722 if (dev == NULL) {
723 dev_err(&interface->dev, "Out of memory\n");
724 retval = -ENOMEM;
725 goto exit;
726 }
727
728 mutex_init(&dev->mtx);
729 spin_lock_init(&dev->buflock);
730 dev->udev = udev;
731 init_waitqueue_head(&dev->read_wait);
732 init_waitqueue_head(&dev->write_wait);
733
734 iface_desc = &interface->altsetting[0];
735
736 /* set up the endpoint information */
737 for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
738 endpoint = &iface_desc->endpoint[i].desc;
739
740 if (usb_endpoint_is_int_in(endpoint))
741 dev->interrupt_in_endpoint = endpoint;
742
743 if (usb_endpoint_is_int_out(endpoint))
744 dev->interrupt_out_endpoint = endpoint;
745 }
746 if (dev->interrupt_in_endpoint == NULL) {
747 dev_err(&interface->dev, "interrupt in endpoint not found\n");
748 goto error;
749 }
750 if (dev->interrupt_out_endpoint == NULL) {
751 dev_err(&interface->dev, "interrupt out endpoint not found\n");
752 goto error;
753 }
754
755 in_end_size = le16_to_cpu(dev->interrupt_in_endpoint->wMaxPacketSize);
756 out_end_size = le16_to_cpu(dev->interrupt_out_endpoint->wMaxPacketSize);
757
758 dev->read_buffer_primary = kmalloc((4 * in_end_size), GFP_KERNEL);
759 if (!dev->read_buffer_primary) {
760 dev_err(&interface->dev, "Couldn't allocate read_buffer_primary\n");
761 retval = -ENOMEM;
762 goto error;
763 }
764
765 /* debug code prime the buffer */
766 memset(dev->read_buffer_primary, 'a', in_end_size);
767 memset(dev->read_buffer_primary + in_end_size, 'b', in_end_size);
768 memset(dev->read_buffer_primary + (2 * in_end_size), 'c', in_end_size);
769 memset(dev->read_buffer_primary + (3 * in_end_size), 'd', in_end_size);
770
771 dev->read_buffer_secondary = kmalloc((4 * in_end_size), GFP_KERNEL);
772 if (!dev->read_buffer_secondary) {
773 dev_err(&interface->dev, "Couldn't allocate read_buffer_secondary\n");
774 retval = -ENOMEM;
775 goto error;
776 }
777
778 /* debug code prime the buffer */
779 memset(dev->read_buffer_secondary, 'e', in_end_size);
780 memset(dev->read_buffer_secondary + in_end_size, 'f', in_end_size);
781 memset(dev->read_buffer_secondary + (2 * in_end_size), 'g', in_end_size);
782 memset(dev->read_buffer_secondary + (3 * in_end_size), 'h', in_end_size);
783
784 dev->interrupt_in_buffer = kmalloc(in_end_size, GFP_KERNEL);
785 if (!dev->interrupt_in_buffer) {
786 dev_err(&interface->dev, "Couldn't allocate interrupt_in_buffer\n");
787 goto error;
788 }
789
790 /* debug code prime the buffer */
791 memset(dev->interrupt_in_buffer, 'i', in_end_size);
792
793 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
794 if (!dev->interrupt_in_urb) {
795 dev_err(&interface->dev, "Couldn't allocate interrupt_in_urb\n");
796 goto error;
797 }
798 dev->interrupt_out_buffer = kmalloc(out_end_size, GFP_KERNEL);
799 if (!dev->interrupt_out_buffer) {
800 dev_err(&interface->dev, "Couldn't allocate interrupt_out_buffer\n");
801 goto error;
802 }
803 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
804 if (!dev->interrupt_out_urb) {
805 dev_err(&interface->dev, "Couldn't allocate interrupt_out_urb\n");
806 goto error;
807 }
808
809 if (!usb_string(udev, udev->descriptor.iSerialNumber, dev->serial_number,
810 sizeof(dev->serial_number))) {
811 dev_err(&interface->dev, "Could not retrieve serial number\n");
812 goto error;
813 }
814 dbg(2," %s : serial_number=%s", __func__, dev->serial_number);
815
816 /* we can register the device now, as it is ready */
817 usb_set_intfdata(interface, dev);
818
819 retval = usb_register_dev(interface, &adu_class);
820
821 if (retval) {
822 /* something prevented us from registering this driver */
823 dev_err(&interface->dev, "Not able to get a minor for this device.\n");
824 usb_set_intfdata(interface, NULL);
825 goto error;
826 }
827
828 dev->minor = interface->minor;
829
830 /* let the user know what node this device is now attached to */
831 dev_info(&interface->dev, "ADU%d %s now attached to /dev/usb/adutux%d\n",
832 udev->descriptor.idProduct, dev->serial_number,
833 (dev->minor - ADU_MINOR_BASE));
834exit:
835 dbg(2," %s : leave, return value %p (dev)", __func__, dev);
836
837 return retval;
838
839error:
840 adu_delete(dev);
841 return retval;
842}
843
844/**
845 * adu_disconnect
846 *
847 * Called by the usb core when the device is removed from the system.
848 */
849static void adu_disconnect(struct usb_interface *interface)
850{
851 struct adu_device *dev;
852 int minor;
853
854 dbg(2," %s : enter", __func__);
855
856 dev = usb_get_intfdata(interface);
857
858 mutex_lock(&dev->mtx); /* not interruptible */
859 dev->udev = NULL; /* poison */
860 minor = dev->minor;
861 usb_deregister_dev(interface, &adu_class);
862 mutex_unlock(&dev->mtx);
863
864 mutex_lock(&adutux_mutex);
865 usb_set_intfdata(interface, NULL);
866
867 /* if the device is not opened, then we clean up right now */
868 dbg(2," %s : open count %d", __func__, dev->open_count);
869 if (!dev->open_count)
870 adu_delete(dev);
871
872 mutex_unlock(&adutux_mutex);
873
874 dev_info(&interface->dev, "ADU device adutux%d now disconnected\n",
875 (minor - ADU_MINOR_BASE));
876
877 dbg(2," %s : leave", __func__);
878}
879
880/* usb specific object needed to register this driver with the usb subsystem */
881static struct usb_driver adu_driver = {
882 .name = "adutux",
883 .probe = adu_probe,
884 .disconnect = adu_disconnect,
885 .id_table = device_table,
886};
887
888static int __init adu_init(void)
889{
890 int result;
891
892 dbg(2," %s : enter", __func__);
893
894 /* register this driver with the USB subsystem */
895 result = usb_register(&adu_driver);
896 if (result < 0) {
897 printk(KERN_ERR "usb_register failed for the "__FILE__
898 " driver. Error number %d\n", result);
899 goto exit;
900 }
901
902 printk(KERN_INFO "adutux " DRIVER_DESC " " DRIVER_VERSION "\n");
903 printk(KERN_INFO "adutux is an experimental driver. "
904 "Use at your own risk\n");
905
906exit:
907 dbg(2," %s : leave, return value %d", __func__, result);
908
909 return result;
910}
911
912static void __exit adu_exit(void)
913{
914 dbg(2," %s : enter", __func__);
915 /* deregister this driver with the USB subsystem */
916 usb_deregister(&adu_driver);
917 dbg(2," %s : leave", __func__);
918}
919
920module_init(adu_init);
921module_exit(adu_exit);
922
923MODULE_AUTHOR(DRIVER_AUTHOR);
924MODULE_DESCRIPTION(DRIVER_DESC);
925MODULE_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");