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 */ |
36 | static 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 | |
46 | MODULE_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 */ |
70 | struct 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 | |
101 | static DEFINE_MUTEX(adutux_mutex); |
102 | |
103 | static struct usb_driver adu_driver; |
104 | |
105 | static 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 | */ |
116 | static 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(lock: &dev->buflock, flags); |
129 | usb_kill_urb(urb: dev->interrupt_in_urb); |
130 | } else |
131 | spin_unlock_irqrestore(lock: &dev->buflock, flags); |
132 | |
133 | spin_lock_irqsave(&dev->buflock, flags); |
134 | if (!dev->out_urb_finished) { |
135 | spin_unlock_irqrestore(lock: &dev->buflock, flags); |
136 | wait_event_timeout(dev->write_wait, dev->out_urb_finished, |
137 | COMMAND_TIMEOUT); |
138 | usb_kill_urb(urb: dev->interrupt_out_urb); |
139 | } else |
140 | spin_unlock_irqrestore(lock: &dev->buflock, flags); |
141 | } |
142 | |
143 | static void adu_delete(struct adu_device *dev) |
144 | { |
145 | /* free data structures */ |
146 | usb_free_urb(urb: dev->interrupt_in_urb); |
147 | usb_free_urb(urb: dev->interrupt_out_urb); |
148 | kfree(objp: dev->read_buffer_primary); |
149 | kfree(objp: dev->read_buffer_secondary); |
150 | kfree(objp: dev->interrupt_in_buffer); |
151 | kfree(objp: dev->interrupt_out_buffer); |
152 | usb_put_dev(dev: dev->udev); |
153 | kfree(objp: dev); |
154 | } |
155 | |
156 | static 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: &dev->udev->dev, function: __func__, |
163 | size: urb->actual_length, data: 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(epd: 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 | |
194 | exit: |
195 | dev->read_urb_finished = 1; |
196 | spin_unlock_irqrestore(lock: &dev->buflock, flags); |
197 | /* always wake up so we recover from errors */ |
198 | wake_up_interruptible(&dev->read_wait); |
199 | } |
200 | |
201 | static 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: &dev->udev->dev, function: __func__, |
208 | size: urb->actual_length, data: 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(lock: &dev->buflock, flags); |
225 | } |
226 | |
227 | static 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(drv: &adu_driver, minor: 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(intf: 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(urb: dev->interrupt_in_urb, dev: dev->udev, |
272 | usb_rcvintpipe(dev->udev, |
273 | dev->interrupt_in_endpoint->bEndpointAddress), |
274 | transfer_buffer: dev->interrupt_in_buffer, |
275 | buffer_length: usb_endpoint_maxp(epd: dev->interrupt_in_endpoint), |
276 | complete_fn: adu_interrupt_in_callback, context: dev, |
277 | interval: dev->interrupt_in_endpoint->bInterval); |
278 | dev->read_urb_finished = 0; |
279 | if (usb_submit_urb(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 | |
289 | exit_no_device: |
290 | mutex_unlock(lock: &adutux_mutex); |
291 | exit_no_lock: |
292 | return retval; |
293 | } |
294 | |
295 | static 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 | |
307 | static 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 | } |
337 | unlock: |
338 | mutex_unlock(lock: &adutux_mutex); |
339 | exit: |
340 | return retval; |
341 | } |
342 | |
343 | static 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(to: buffer, from: dev->read_buffer_secondary+dev->secondary_head, n: 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 | dev_dbg(&dev->udev->dev, |
398 | "%s : swap, read_buffer_length = %d\n" , |
399 | __func__, dev->read_buffer_length); |
400 | swap(dev->read_buffer_primary, dev->read_buffer_secondary); |
401 | dev->secondary_head = 0; |
402 | dev->secondary_tail = dev->read_buffer_length; |
403 | dev->read_buffer_length = 0; |
404 | spin_unlock_irqrestore(lock: &dev->buflock, flags); |
405 | /* we have a free buffer so use it */ |
406 | should_submit = 1; |
407 | } else { |
408 | /* even the primary was empty - we may need to do IO */ |
409 | if (!dev->read_urb_finished) { |
410 | /* somebody is doing IO */ |
411 | spin_unlock_irqrestore(lock: &dev->buflock, flags); |
412 | dev_dbg(&dev->udev->dev, |
413 | "%s : submitted already\n" , |
414 | __func__); |
415 | } else { |
416 | /* we must initiate input */ |
417 | dev_dbg(&dev->udev->dev, |
418 | "%s : initiate input\n" , |
419 | __func__); |
420 | dev->read_urb_finished = 0; |
421 | spin_unlock_irqrestore(lock: &dev->buflock, flags); |
422 | |
423 | usb_fill_int_urb(urb: dev->interrupt_in_urb, dev: dev->udev, |
424 | usb_rcvintpipe(dev->udev, |
425 | dev->interrupt_in_endpoint->bEndpointAddress), |
426 | transfer_buffer: dev->interrupt_in_buffer, |
427 | buffer_length: usb_endpoint_maxp(epd: dev->interrupt_in_endpoint), |
428 | complete_fn: adu_interrupt_in_callback, |
429 | context: dev, |
430 | interval: dev->interrupt_in_endpoint->bInterval); |
431 | retval = usb_submit_urb(urb: dev->interrupt_in_urb, GFP_KERNEL); |
432 | if (retval) { |
433 | dev->read_urb_finished = 1; |
434 | if (retval == -ENOMEM) { |
435 | retval = bytes_read ? bytes_read : -ENOMEM; |
436 | } |
437 | dev_dbg(&dev->udev->dev, |
438 | "%s : submit failed\n" , |
439 | __func__); |
440 | goto exit; |
441 | } |
442 | } |
443 | |
444 | /* we wait for I/O to complete */ |
445 | set_current_state(TASK_INTERRUPTIBLE); |
446 | add_wait_queue(wq_head: &dev->read_wait, wq_entry: &wait); |
447 | spin_lock_irqsave(&dev->buflock, flags); |
448 | if (!dev->read_urb_finished) { |
449 | spin_unlock_irqrestore(lock: &dev->buflock, flags); |
450 | timeout = schedule_timeout(COMMAND_TIMEOUT); |
451 | } else { |
452 | spin_unlock_irqrestore(lock: &dev->buflock, flags); |
453 | set_current_state(TASK_RUNNING); |
454 | } |
455 | remove_wait_queue(wq_head: &dev->read_wait, wq_entry: &wait); |
456 | |
457 | if (timeout <= 0) { |
458 | dev_dbg(&dev->udev->dev, |
459 | "%s : timeout\n" , __func__); |
460 | retval = bytes_read ? bytes_read : -ETIMEDOUT; |
461 | goto exit; |
462 | } |
463 | |
464 | if (signal_pending(current)) { |
465 | dev_dbg(&dev->udev->dev, |
466 | "%s : signal pending\n" , |
467 | __func__); |
468 | retval = bytes_read ? bytes_read : -EINTR; |
469 | goto exit; |
470 | } |
471 | } |
472 | } |
473 | } |
474 | |
475 | retval = bytes_read; |
476 | /* if the primary buffer is empty then use it */ |
477 | spin_lock_irqsave(&dev->buflock, flags); |
478 | if (should_submit && dev->read_urb_finished) { |
479 | dev->read_urb_finished = 0; |
480 | spin_unlock_irqrestore(lock: &dev->buflock, flags); |
481 | usb_fill_int_urb(urb: dev->interrupt_in_urb, dev: dev->udev, |
482 | usb_rcvintpipe(dev->udev, |
483 | dev->interrupt_in_endpoint->bEndpointAddress), |
484 | transfer_buffer: dev->interrupt_in_buffer, |
485 | buffer_length: usb_endpoint_maxp(epd: dev->interrupt_in_endpoint), |
486 | complete_fn: adu_interrupt_in_callback, |
487 | context: dev, |
488 | interval: dev->interrupt_in_endpoint->bInterval); |
489 | if (usb_submit_urb(urb: dev->interrupt_in_urb, GFP_KERNEL) != 0) |
490 | dev->read_urb_finished = 1; |
491 | /* we ignore failure */ |
492 | } else { |
493 | spin_unlock_irqrestore(lock: &dev->buflock, flags); |
494 | } |
495 | |
496 | exit: |
497 | /* unlock the device */ |
498 | mutex_unlock(lock: &dev->mtx); |
499 | |
500 | return retval; |
501 | } |
502 | |
503 | static ssize_t adu_write(struct file *file, const __user char *buffer, |
504 | size_t count, loff_t *ppos) |
505 | { |
506 | DECLARE_WAITQUEUE(waita, current); |
507 | struct adu_device *dev; |
508 | size_t bytes_written = 0; |
509 | size_t bytes_to_write; |
510 | size_t buffer_size; |
511 | unsigned long flags; |
512 | int retval; |
513 | |
514 | dev = file->private_data; |
515 | |
516 | retval = mutex_lock_interruptible(&dev->mtx); |
517 | if (retval) |
518 | goto exit_nolock; |
519 | |
520 | /* verify that the device wasn't unplugged */ |
521 | if (dev->disconnected) { |
522 | retval = -ENODEV; |
523 | pr_err("No device or device unplugged %d\n" , retval); |
524 | goto exit; |
525 | } |
526 | |
527 | /* verify that we actually have some data to write */ |
528 | if (count == 0) { |
529 | dev_dbg(&dev->udev->dev, "%s : write request of 0 bytes\n" , |
530 | __func__); |
531 | goto exit; |
532 | } |
533 | |
534 | while (count > 0) { |
535 | add_wait_queue(wq_head: &dev->write_wait, wq_entry: &waita); |
536 | set_current_state(TASK_INTERRUPTIBLE); |
537 | spin_lock_irqsave(&dev->buflock, flags); |
538 | if (!dev->out_urb_finished) { |
539 | spin_unlock_irqrestore(lock: &dev->buflock, flags); |
540 | |
541 | mutex_unlock(lock: &dev->mtx); |
542 | if (signal_pending(current)) { |
543 | dev_dbg(&dev->udev->dev, "%s : interrupted\n" , |
544 | __func__); |
545 | set_current_state(TASK_RUNNING); |
546 | retval = -EINTR; |
547 | goto exit_onqueue; |
548 | } |
549 | if (schedule_timeout(COMMAND_TIMEOUT) == 0) { |
550 | dev_dbg(&dev->udev->dev, |
551 | "%s - command timed out.\n" , __func__); |
552 | retval = -ETIMEDOUT; |
553 | goto exit_onqueue; |
554 | } |
555 | remove_wait_queue(wq_head: &dev->write_wait, wq_entry: &waita); |
556 | retval = mutex_lock_interruptible(&dev->mtx); |
557 | if (retval) { |
558 | retval = bytes_written ? bytes_written : retval; |
559 | goto exit_nolock; |
560 | } |
561 | |
562 | dev_dbg(&dev->udev->dev, |
563 | "%s : in progress, count = %zd\n" , |
564 | __func__, count); |
565 | } else { |
566 | spin_unlock_irqrestore(lock: &dev->buflock, flags); |
567 | set_current_state(TASK_RUNNING); |
568 | remove_wait_queue(wq_head: &dev->write_wait, wq_entry: &waita); |
569 | dev_dbg(&dev->udev->dev, "%s : sending, count = %zd\n" , |
570 | __func__, count); |
571 | |
572 | /* write the data into interrupt_out_buffer from userspace */ |
573 | buffer_size = usb_endpoint_maxp(epd: dev->interrupt_out_endpoint); |
574 | bytes_to_write = count > buffer_size ? buffer_size : count; |
575 | dev_dbg(&dev->udev->dev, |
576 | "%s : buffer_size = %zd, count = %zd, bytes_to_write = %zd\n" , |
577 | __func__, buffer_size, count, bytes_to_write); |
578 | |
579 | if (copy_from_user(to: dev->interrupt_out_buffer, from: buffer, n: bytes_to_write) != 0) { |
580 | retval = -EFAULT; |
581 | goto exit; |
582 | } |
583 | |
584 | /* send off the urb */ |
585 | usb_fill_int_urb( |
586 | urb: dev->interrupt_out_urb, |
587 | dev: dev->udev, |
588 | usb_sndintpipe(dev->udev, dev->interrupt_out_endpoint->bEndpointAddress), |
589 | transfer_buffer: dev->interrupt_out_buffer, |
590 | buffer_length: bytes_to_write, |
591 | complete_fn: adu_interrupt_out_callback, |
592 | context: dev, |
593 | interval: dev->interrupt_out_endpoint->bInterval); |
594 | dev->interrupt_out_urb->actual_length = bytes_to_write; |
595 | dev->out_urb_finished = 0; |
596 | retval = usb_submit_urb(urb: dev->interrupt_out_urb, GFP_KERNEL); |
597 | if (retval < 0) { |
598 | dev->out_urb_finished = 1; |
599 | dev_err(&dev->udev->dev, "Couldn't submit " |
600 | "interrupt_out_urb %d\n" , retval); |
601 | goto exit; |
602 | } |
603 | |
604 | buffer += bytes_to_write; |
605 | count -= bytes_to_write; |
606 | |
607 | bytes_written += bytes_to_write; |
608 | } |
609 | } |
610 | mutex_unlock(lock: &dev->mtx); |
611 | return bytes_written; |
612 | |
613 | exit: |
614 | mutex_unlock(lock: &dev->mtx); |
615 | exit_nolock: |
616 | return retval; |
617 | |
618 | exit_onqueue: |
619 | remove_wait_queue(wq_head: &dev->write_wait, wq_entry: &waita); |
620 | return retval; |
621 | } |
622 | |
623 | /* file operations needed when we register this driver */ |
624 | static const struct file_operations adu_fops = { |
625 | .owner = THIS_MODULE, |
626 | .read = adu_read, |
627 | .write = adu_write, |
628 | .open = adu_open, |
629 | .release = adu_release, |
630 | .llseek = noop_llseek, |
631 | }; |
632 | |
633 | /* |
634 | * usb class driver info in order to get a minor number from the usb core, |
635 | * and to have the device registered with devfs and the driver core |
636 | */ |
637 | static struct usb_class_driver adu_class = { |
638 | .name = "usb/adutux%d" , |
639 | .fops = &adu_fops, |
640 | .minor_base = ADU_MINOR_BASE, |
641 | }; |
642 | |
643 | /* |
644 | * adu_probe |
645 | * |
646 | * Called by the usb core when a new device is connected that it thinks |
647 | * this driver might be interested in. |
648 | */ |
649 | static int adu_probe(struct usb_interface *interface, |
650 | const struct usb_device_id *id) |
651 | { |
652 | struct usb_device *udev = interface_to_usbdev(interface); |
653 | struct adu_device *dev = NULL; |
654 | int retval = -ENOMEM; |
655 | int in_end_size; |
656 | int out_end_size; |
657 | int res; |
658 | |
659 | /* allocate memory for our device state and initialize it */ |
660 | dev = kzalloc(size: sizeof(struct adu_device), GFP_KERNEL); |
661 | if (!dev) |
662 | return -ENOMEM; |
663 | |
664 | mutex_init(&dev->mtx); |
665 | spin_lock_init(&dev->buflock); |
666 | dev->udev = usb_get_dev(dev: udev); |
667 | init_waitqueue_head(&dev->read_wait); |
668 | init_waitqueue_head(&dev->write_wait); |
669 | |
670 | res = usb_find_common_endpoints_reverse(alt: interface->cur_altsetting, |
671 | NULL, NULL, |
672 | int_in: &dev->interrupt_in_endpoint, |
673 | int_out: &dev->interrupt_out_endpoint); |
674 | if (res) { |
675 | dev_err(&interface->dev, "interrupt endpoints not found\n" ); |
676 | retval = res; |
677 | goto error; |
678 | } |
679 | |
680 | in_end_size = usb_endpoint_maxp(epd: dev->interrupt_in_endpoint); |
681 | out_end_size = usb_endpoint_maxp(epd: dev->interrupt_out_endpoint); |
682 | |
683 | dev->read_buffer_primary = kmalloc(size: (4 * in_end_size), GFP_KERNEL); |
684 | if (!dev->read_buffer_primary) |
685 | goto error; |
686 | |
687 | /* debug code prime the buffer */ |
688 | memset(dev->read_buffer_primary, 'a', in_end_size); |
689 | memset(dev->read_buffer_primary + in_end_size, 'b', in_end_size); |
690 | memset(dev->read_buffer_primary + (2 * in_end_size), 'c', in_end_size); |
691 | memset(dev->read_buffer_primary + (3 * in_end_size), 'd', in_end_size); |
692 | |
693 | dev->read_buffer_secondary = kmalloc(size: (4 * in_end_size), GFP_KERNEL); |
694 | if (!dev->read_buffer_secondary) |
695 | goto error; |
696 | |
697 | /* debug code prime the buffer */ |
698 | memset(dev->read_buffer_secondary, 'e', in_end_size); |
699 | memset(dev->read_buffer_secondary + in_end_size, 'f', in_end_size); |
700 | memset(dev->read_buffer_secondary + (2 * in_end_size), 'g', in_end_size); |
701 | memset(dev->read_buffer_secondary + (3 * in_end_size), 'h', in_end_size); |
702 | |
703 | dev->interrupt_in_buffer = kmalloc(size: in_end_size, GFP_KERNEL); |
704 | if (!dev->interrupt_in_buffer) |
705 | goto error; |
706 | |
707 | /* debug code prime the buffer */ |
708 | memset(dev->interrupt_in_buffer, 'i', in_end_size); |
709 | |
710 | dev->interrupt_in_urb = usb_alloc_urb(iso_packets: 0, GFP_KERNEL); |
711 | if (!dev->interrupt_in_urb) |
712 | goto error; |
713 | dev->interrupt_out_buffer = kmalloc(size: out_end_size, GFP_KERNEL); |
714 | if (!dev->interrupt_out_buffer) |
715 | goto error; |
716 | dev->interrupt_out_urb = usb_alloc_urb(iso_packets: 0, GFP_KERNEL); |
717 | if (!dev->interrupt_out_urb) |
718 | goto error; |
719 | |
720 | if (!usb_string(dev: udev, index: udev->descriptor.iSerialNumber, buf: dev->serial_number, |
721 | size: sizeof(dev->serial_number))) { |
722 | dev_err(&interface->dev, "Could not retrieve serial number\n" ); |
723 | retval = -EIO; |
724 | goto error; |
725 | } |
726 | dev_dbg(&interface->dev, "serial_number=%s" , dev->serial_number); |
727 | |
728 | /* we can register the device now, as it is ready */ |
729 | usb_set_intfdata(intf: interface, data: dev); |
730 | |
731 | retval = usb_register_dev(intf: interface, class_driver: &adu_class); |
732 | |
733 | if (retval) { |
734 | /* something prevented us from registering this driver */ |
735 | dev_err(&interface->dev, "Not able to get a minor for this device.\n" ); |
736 | usb_set_intfdata(intf: interface, NULL); |
737 | goto error; |
738 | } |
739 | |
740 | dev->minor = interface->minor; |
741 | |
742 | /* let the user know what node this device is now attached to */ |
743 | dev_info(&interface->dev, "ADU%d %s now attached to /dev/usb/adutux%d\n" , |
744 | le16_to_cpu(udev->descriptor.idProduct), dev->serial_number, |
745 | (dev->minor - ADU_MINOR_BASE)); |
746 | |
747 | return 0; |
748 | |
749 | error: |
750 | adu_delete(dev); |
751 | return retval; |
752 | } |
753 | |
754 | /* |
755 | * adu_disconnect |
756 | * |
757 | * Called by the usb core when the device is removed from the system. |
758 | */ |
759 | static void adu_disconnect(struct usb_interface *interface) |
760 | { |
761 | struct adu_device *dev; |
762 | |
763 | dev = usb_get_intfdata(intf: interface); |
764 | |
765 | usb_deregister_dev(intf: interface, class_driver: &adu_class); |
766 | |
767 | usb_poison_urb(urb: dev->interrupt_in_urb); |
768 | usb_poison_urb(urb: dev->interrupt_out_urb); |
769 | |
770 | mutex_lock(&adutux_mutex); |
771 | usb_set_intfdata(intf: interface, NULL); |
772 | |
773 | mutex_lock(&dev->mtx); /* not interruptible */ |
774 | dev->disconnected = 1; |
775 | mutex_unlock(lock: &dev->mtx); |
776 | |
777 | /* if the device is not opened, then we clean up right now */ |
778 | if (!dev->open_count) |
779 | adu_delete(dev); |
780 | |
781 | mutex_unlock(lock: &adutux_mutex); |
782 | } |
783 | |
784 | /* usb specific object needed to register this driver with the usb subsystem */ |
785 | static struct usb_driver adu_driver = { |
786 | .name = "adutux" , |
787 | .probe = adu_probe, |
788 | .disconnect = adu_disconnect, |
789 | .id_table = device_table, |
790 | }; |
791 | |
792 | module_usb_driver(adu_driver); |
793 | |
794 | MODULE_AUTHOR(DRIVER_AUTHOR); |
795 | MODULE_DESCRIPTION(DRIVER_DESC); |
796 | MODULE_LICENSE("GPL" ); |
797 | |