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bpf: Prevent memory disambiguation attack
[linux/fpc-iii.git] / drivers / usb / misc / ldusb.c
blob236a60f53099e042faa9d804f4c470b1d5b90ef1
1 // SPDX-License-Identifier: GPL-2.0+
2 /**
3 * Generic USB driver for report based interrupt in/out devices
4 * like LD Didactic's USB devices. LD Didactic's USB devices are
5 * HID devices which do not use HID report definitons (they use
6 * raw interrupt in and our reports only for communication).
7 *
8 * This driver uses a ring buffer for time critical reading of
9 * interrupt in reports and provides read and write methods for
10 * raw interrupt reports (similar to the Windows HID driver).
11 * Devices based on the book USB COMPLETE by Jan Axelson may need
12 * such a compatibility to the Windows HID driver.
13 *
14 * Copyright (C) 2005 Michael Hund <mhund@ld-didactic.de>
15 *
16 * Derived from Lego USB Tower driver
17 * Copyright (C) 2003 David Glance <advidgsf@sourceforge.net>
18 * 2001-2004 Juergen Stuber <starblue@users.sourceforge.net>
19 */
20
21 #include <linux/kernel.h>
22 #include <linux/errno.h>
23 #include <linux/slab.h>
24 #include <linux/module.h>
25 #include <linux/mutex.h>
26
27 #include <linux/uaccess.h>
28 #include <linux/input.h>
29 #include <linux/usb.h>
30 #include <linux/poll.h>
31
32 /* Define these values to match your devices */
33 #define USB_VENDOR_ID_LD 0x0f11 /* USB Vendor ID of LD Didactic GmbH */
34 #define USB_DEVICE_ID_LD_CASSY 0x1000 /* USB Product ID of CASSY-S modules with 8 bytes endpoint size */
35 #define USB_DEVICE_ID_LD_CASSY2 0x1001 /* USB Product ID of CASSY-S modules with 64 bytes endpoint size */
36 #define USB_DEVICE_ID_LD_POCKETCASSY 0x1010 /* USB Product ID of Pocket-CASSY */
37 #define USB_DEVICE_ID_LD_POCKETCASSY2 0x1011 /* USB Product ID of Pocket-CASSY 2 (reserved) */
38 #define USB_DEVICE_ID_LD_MOBILECASSY 0x1020 /* USB Product ID of Mobile-CASSY */
39 #define USB_DEVICE_ID_LD_MOBILECASSY2 0x1021 /* USB Product ID of Mobile-CASSY 2 (reserved) */
40 #define USB_DEVICE_ID_LD_MICROCASSYVOLTAGE 0x1031 /* USB Product ID of Micro-CASSY Voltage */
41 #define USB_DEVICE_ID_LD_MICROCASSYCURRENT 0x1032 /* USB Product ID of Micro-CASSY Current */
42 #define USB_DEVICE_ID_LD_MICROCASSYTIME 0x1033 /* USB Product ID of Micro-CASSY Time (reserved) */
43 #define USB_DEVICE_ID_LD_MICROCASSYTEMPERATURE 0x1035 /* USB Product ID of Micro-CASSY Temperature */
44 #define USB_DEVICE_ID_LD_MICROCASSYPH 0x1038 /* USB Product ID of Micro-CASSY pH */
45 #define USB_DEVICE_ID_LD_POWERANALYSERCASSY 0x1040 /* USB Product ID of Power Analyser CASSY */
46 #define USB_DEVICE_ID_LD_CONVERTERCONTROLLERCASSY 0x1042 /* USB Product ID of Converter Controller CASSY */
47 #define USB_DEVICE_ID_LD_MACHINETESTCASSY 0x1043 /* USB Product ID of Machine Test CASSY */
48 #define USB_DEVICE_ID_LD_JWM 0x1080 /* USB Product ID of Joule and Wattmeter */
49 #define USB_DEVICE_ID_LD_DMMP 0x1081 /* USB Product ID of Digital Multimeter P (reserved) */
50 #define USB_DEVICE_ID_LD_UMIP 0x1090 /* USB Product ID of UMI P */
51 #define USB_DEVICE_ID_LD_UMIC 0x10A0 /* USB Product ID of UMI C */
52 #define USB_DEVICE_ID_LD_UMIB 0x10B0 /* USB Product ID of UMI B */
53 #define USB_DEVICE_ID_LD_XRAY 0x1100 /* USB Product ID of X-Ray Apparatus 55481 */
54 #define USB_DEVICE_ID_LD_XRAY2 0x1101 /* USB Product ID of X-Ray Apparatus 554800 */
55 #define USB_DEVICE_ID_LD_XRAYCT 0x1110 /* USB Product ID of X-Ray Apparatus CT 554821*/
56 #define USB_DEVICE_ID_LD_VIDEOCOM 0x1200 /* USB Product ID of VideoCom */
57 #define USB_DEVICE_ID_LD_MOTOR 0x1210 /* USB Product ID of Motor (reserved) */
58 #define USB_DEVICE_ID_LD_COM3LAB 0x2000 /* USB Product ID of COM3LAB */
59 #define USB_DEVICE_ID_LD_TELEPORT 0x2010 /* USB Product ID of Terminal Adapter */
60 #define USB_DEVICE_ID_LD_NETWORKANALYSER 0x2020 /* USB Product ID of Network Analyser */
61 #define USB_DEVICE_ID_LD_POWERCONTROL 0x2030 /* USB Product ID of Converter Control Unit */
62 #define USB_DEVICE_ID_LD_MACHINETEST 0x2040 /* USB Product ID of Machine Test System */
63 #define USB_DEVICE_ID_LD_MOSTANALYSER 0x2050 /* USB Product ID of MOST Protocol Analyser */
64 #define USB_DEVICE_ID_LD_MOSTANALYSER2 0x2051 /* USB Product ID of MOST Protocol Analyser 2 */
65 #define USB_DEVICE_ID_LD_ABSESP 0x2060 /* USB Product ID of ABS ESP */
66 #define USB_DEVICE_ID_LD_AUTODATABUS 0x2070 /* USB Product ID of Automotive Data Buses */
67 #define USB_DEVICE_ID_LD_MCT 0x2080 /* USB Product ID of Microcontroller technique */
68 #define USB_DEVICE_ID_LD_HYBRID 0x2090 /* USB Product ID of Automotive Hybrid */
69 #define USB_DEVICE_ID_LD_HEATCONTROL 0x20A0 /* USB Product ID of Heat control */
70
71 #ifdef CONFIG_USB_DYNAMIC_MINORS
72 #define USB_LD_MINOR_BASE 0
73 #else
74 #define USB_LD_MINOR_BASE 176
75 #endif
76
77 /* table of devices that work with this driver */
78 static const struct usb_device_id ld_usb_table[] = {
79 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CASSY) },
80 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CASSY2) },
81 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POCKETCASSY) },
82 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POCKETCASSY2) },
83 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOBILECASSY) },
84 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOBILECASSY2) },
85 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYVOLTAGE) },
86 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYCURRENT) },
87 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYTIME) },
88 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYTEMPERATURE) },
89 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MICROCASSYPH) },
90 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POWERANALYSERCASSY) },
91 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_CONVERTERCONTROLLERCASSY) },
92 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MACHINETESTCASSY) },
93 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_JWM) },
94 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_DMMP) },
95 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIP) },
96 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIC) },
97 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_UMIB) },
98 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY) },
99 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_XRAY2) },
100 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_VIDEOCOM) },
101 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOTOR) },
102 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_COM3LAB) },
103 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_TELEPORT) },
104 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_NETWORKANALYSER) },
105 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_POWERCONTROL) },
106 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MACHINETEST) },
107 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOSTANALYSER) },
108 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MOSTANALYSER2) },
109 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_ABSESP) },
110 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_AUTODATABUS) },
111 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_MCT) },
112 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_HYBRID) },
113 { USB_DEVICE(USB_VENDOR_ID_LD, USB_DEVICE_ID_LD_HEATCONTROL) },
114 { } /* Terminating entry */
115 };
116 MODULE_DEVICE_TABLE(usb, ld_usb_table);
117 MODULE_AUTHOR("Michael Hund <mhund@ld-didactic.de>");
118 MODULE_DESCRIPTION("LD USB Driver");
119 MODULE_LICENSE("GPL");
120 MODULE_SUPPORTED_DEVICE("LD USB Devices");
121
122 /* All interrupt in transfers are collected in a ring buffer to
123 * avoid racing conditions and get better performance of the driver.
124 */
125 static int ring_buffer_size = 128;
126 module_param(ring_buffer_size, int, 0000);
127 MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size in reports");
128
129 /* The write_buffer can contain more than one interrupt out transfer.
130 */
131 static int write_buffer_size = 10;
132 module_param(write_buffer_size, int, 0000);
133 MODULE_PARM_DESC(write_buffer_size, "Write buffer size in reports");
134
135 /* As of kernel version 2.6.4 ehci-hcd uses an
136 * "only one interrupt transfer per frame" shortcut
137 * to simplify the scheduling of periodic transfers.
138 * This conflicts with our standard 1ms intervals for in and out URBs.
139 * We use default intervals of 2ms for in and 2ms for out transfers,
140 * which should be fast enough.
141 * Increase the interval to allow more devices that do interrupt transfers,
142 * or set to 1 to use the standard interval from the endpoint descriptors.
143 */
144 static int min_interrupt_in_interval = 2;
145 module_param(min_interrupt_in_interval, int, 0000);
146 MODULE_PARM_DESC(min_interrupt_in_interval, "Minimum interrupt in interval in ms");
147
148 static int min_interrupt_out_interval = 2;
149 module_param(min_interrupt_out_interval, int, 0000);
150 MODULE_PARM_DESC(min_interrupt_out_interval, "Minimum interrupt out interval in ms");
151
152 /* Structure to hold all of our device specific stuff */
153 struct ld_usb {
154 struct mutex mutex; /* locks this structure */
155 struct usb_interface *intf; /* save off the usb interface pointer */
156
157 int open_count; /* number of times this port has been opened */
158
159 char *ring_buffer;
160 unsigned int ring_head;
161 unsigned int ring_tail;
162
163 wait_queue_head_t read_wait;
164 wait_queue_head_t write_wait;
165
166 char *interrupt_in_buffer;
167 struct usb_endpoint_descriptor *interrupt_in_endpoint;
168 struct urb *interrupt_in_urb;
169 int interrupt_in_interval;
170 size_t interrupt_in_endpoint_size;
171 int interrupt_in_running;
172 int interrupt_in_done;
173 int buffer_overflow;
174 spinlock_t rbsl;
175
176 char *interrupt_out_buffer;
177 struct usb_endpoint_descriptor *interrupt_out_endpoint;
178 struct urb *interrupt_out_urb;
179 int interrupt_out_interval;
180 size_t interrupt_out_endpoint_size;
181 int interrupt_out_busy;
182 };
183
184 static struct usb_driver ld_usb_driver;
185
186 /**
187 * ld_usb_abort_transfers
188 * aborts transfers and frees associated data structures
189 */
190 static void ld_usb_abort_transfers(struct ld_usb *dev)
191 {
192 /* shutdown transfer */
193 if (dev->interrupt_in_running) {
194 dev->interrupt_in_running = 0;
195 if (dev->intf)
196 usb_kill_urb(dev->interrupt_in_urb);
197 }
198 if (dev->interrupt_out_busy)
199 if (dev->intf)
200 usb_kill_urb(dev->interrupt_out_urb);
201 }
202
203 /**
204 * ld_usb_delete
205 */
206 static void ld_usb_delete(struct ld_usb *dev)
207 {
208 ld_usb_abort_transfers(dev);
209
210 /* free data structures */
211 usb_free_urb(dev->interrupt_in_urb);
212 usb_free_urb(dev->interrupt_out_urb);
213 kfree(dev->ring_buffer);
214 kfree(dev->interrupt_in_buffer);
215 kfree(dev->interrupt_out_buffer);
216 kfree(dev);
217 }
218
219 /**
220 * ld_usb_interrupt_in_callback
221 */
222 static void ld_usb_interrupt_in_callback(struct urb *urb)
223 {
224 struct ld_usb *dev = urb->context;
225 size_t *actual_buffer;
226 unsigned int next_ring_head;
227 int status = urb->status;
228 int retval;
229
230 if (status) {
231 if (status == -ENOENT ||
232 status == -ECONNRESET ||
233 status == -ESHUTDOWN) {
234 goto exit;
235 } else {
236 dev_dbg(&dev->intf->dev,
237 "%s: nonzero status received: %d\n", __func__,
238 status);
239 spin_lock(&dev->rbsl);
240 goto resubmit; /* maybe we can recover */
241 }
242 }
243
244 spin_lock(&dev->rbsl);
245 if (urb->actual_length > 0) {
246 next_ring_head = (dev->ring_head+1) % ring_buffer_size;
247 if (next_ring_head != dev->ring_tail) {
248 actual_buffer = (size_t *)(dev->ring_buffer + dev->ring_head * (sizeof(size_t)+dev->interrupt_in_endpoint_size));
249 /* actual_buffer gets urb->actual_length + interrupt_in_buffer */
250 *actual_buffer = urb->actual_length;
251 memcpy(actual_buffer+1, dev->interrupt_in_buffer, urb->actual_length);
252 dev->ring_head = next_ring_head;
253 dev_dbg(&dev->intf->dev, "%s: received %d bytes\n",
254 __func__, urb->actual_length);
255 } else {
256 dev_warn(&dev->intf->dev,
257 "Ring buffer overflow, %d bytes dropped\n",
258 urb->actual_length);
259 dev->buffer_overflow = 1;
260 }
261 }
262
263 resubmit:
264 /* resubmit if we're still running */
265 if (dev->interrupt_in_running && !dev->buffer_overflow && dev->intf) {
266 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
267 if (retval) {
268 dev_err(&dev->intf->dev,
269 "usb_submit_urb failed (%d)\n", retval);
270 dev->buffer_overflow = 1;
271 }
272 }
273 spin_unlock(&dev->rbsl);
274 exit:
275 dev->interrupt_in_done = 1;
276 wake_up_interruptible(&dev->read_wait);
277 }
278
279 /**
280 * ld_usb_interrupt_out_callback
281 */
282 static void ld_usb_interrupt_out_callback(struct urb *urb)
283 {
284 struct ld_usb *dev = urb->context;
285 int status = urb->status;
286
287 /* sync/async unlink faults aren't errors */
288 if (status && !(status == -ENOENT ||
289 status == -ECONNRESET ||
290 status == -ESHUTDOWN))
291 dev_dbg(&dev->intf->dev,
292 "%s - nonzero write interrupt status received: %d\n",
293 __func__, status);
294
295 dev->interrupt_out_busy = 0;
296 wake_up_interruptible(&dev->write_wait);
297 }
298
299 /**
300 * ld_usb_open
301 */
302 static int ld_usb_open(struct inode *inode, struct file *file)
303 {
304 struct ld_usb *dev;
305 int subminor;
306 int retval;
307 struct usb_interface *interface;
308
309 nonseekable_open(inode, file);
310 subminor = iminor(inode);
311
312 interface = usb_find_interface(&ld_usb_driver, subminor);
313
314 if (!interface) {
315 printk(KERN_ERR "%s - error, can't find device for minor %d\n",
316 __func__, subminor);
317 return -ENODEV;
318 }
319
320 dev = usb_get_intfdata(interface);
321
322 if (!dev)
323 return -ENODEV;
324
325 /* lock this device */
326 if (mutex_lock_interruptible(&dev->mutex))
327 return -ERESTARTSYS;
328
329 /* allow opening only once */
330 if (dev->open_count) {
331 retval = -EBUSY;
332 goto unlock_exit;
333 }
334 dev->open_count = 1;
335
336 /* initialize in direction */
337 dev->ring_head = 0;
338 dev->ring_tail = 0;
339 dev->buffer_overflow = 0;
340 usb_fill_int_urb(dev->interrupt_in_urb,
341 interface_to_usbdev(interface),
342 usb_rcvintpipe(interface_to_usbdev(interface),
343 dev->interrupt_in_endpoint->bEndpointAddress),
344 dev->interrupt_in_buffer,
345 dev->interrupt_in_endpoint_size,
346 ld_usb_interrupt_in_callback,
347 dev,
348 dev->interrupt_in_interval);
349
350 dev->interrupt_in_running = 1;
351 dev->interrupt_in_done = 0;
352
353 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
354 if (retval) {
355 dev_err(&interface->dev, "Couldn't submit interrupt_in_urb %d\n", retval);
356 dev->interrupt_in_running = 0;
357 dev->open_count = 0;
358 goto unlock_exit;
359 }
360
361 /* save device in the file's private structure */
362 file->private_data = dev;
363
364 unlock_exit:
365 mutex_unlock(&dev->mutex);
366
367 return retval;
368 }
369
370 /**
371 * ld_usb_release
372 */
373 static int ld_usb_release(struct inode *inode, struct file *file)
374 {
375 struct ld_usb *dev;
376 int retval = 0;
377
378 dev = file->private_data;
379
380 if (dev == NULL) {
381 retval = -ENODEV;
382 goto exit;
383 }
384
385 if (mutex_lock_interruptible(&dev->mutex)) {
386 retval = -ERESTARTSYS;
387 goto exit;
388 }
389
390 if (dev->open_count != 1) {
391 retval = -ENODEV;
392 goto unlock_exit;
393 }
394 if (dev->intf == NULL) {
395 /* the device was unplugged before the file was released */
396 mutex_unlock(&dev->mutex);
397 /* unlock here as ld_usb_delete frees dev */
398 ld_usb_delete(dev);
399 goto exit;
400 }
401
402 /* wait until write transfer is finished */
403 if (dev->interrupt_out_busy)
404 wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
405 ld_usb_abort_transfers(dev);
406 dev->open_count = 0;
407
408 unlock_exit:
409 mutex_unlock(&dev->mutex);
410
411 exit:
412 return retval;
413 }
414
415 /**
416 * ld_usb_poll
417 */
418 static __poll_t ld_usb_poll(struct file *file, poll_table *wait)
419 {
420 struct ld_usb *dev;
421 __poll_t mask = 0;
422
423 dev = file->private_data;
424
425 if (!dev->intf)
426 return EPOLLERR | EPOLLHUP;
427
428 poll_wait(file, &dev->read_wait, wait);
429 poll_wait(file, &dev->write_wait, wait);
430
431 if (dev->ring_head != dev->ring_tail)
432 mask |= EPOLLIN | EPOLLRDNORM;
433 if (!dev->interrupt_out_busy)
434 mask |= EPOLLOUT | EPOLLWRNORM;
435
436 return mask;
437 }
438
439 /**
440 * ld_usb_read
441 */
442 static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count,
443 loff_t *ppos)
444 {
445 struct ld_usb *dev;
446 size_t *actual_buffer;
447 size_t bytes_to_read;
448 int retval = 0;
449 int rv;
450
451 dev = file->private_data;
452
453 /* verify that we actually have some data to read */
454 if (count == 0)
455 goto exit;
456
457 /* lock this object */
458 if (mutex_lock_interruptible(&dev->mutex)) {
459 retval = -ERESTARTSYS;
460 goto exit;
461 }
462
463 /* verify that the device wasn't unplugged */
464 if (dev->intf == NULL) {
465 retval = -ENODEV;
466 printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval);
467 goto unlock_exit;
468 }
469
470 /* wait for data */
471 spin_lock_irq(&dev->rbsl);
472 if (dev->ring_head == dev->ring_tail) {
473 dev->interrupt_in_done = 0;
474 spin_unlock_irq(&dev->rbsl);
475 if (file->f_flags & O_NONBLOCK) {
476 retval = -EAGAIN;
477 goto unlock_exit;
478 }
479 retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done);
480 if (retval < 0)
481 goto unlock_exit;
482 } else {
483 spin_unlock_irq(&dev->rbsl);
484 }
485
486 /* actual_buffer contains actual_length + interrupt_in_buffer */
487 actual_buffer = (size_t *)(dev->ring_buffer + dev->ring_tail * (sizeof(size_t)+dev->interrupt_in_endpoint_size));
488 bytes_to_read = min(count, *actual_buffer);
489 if (bytes_to_read < *actual_buffer)
490 dev_warn(&dev->intf->dev, "Read buffer overflow, %zd bytes dropped\n",
491 *actual_buffer-bytes_to_read);
492
493 /* copy one interrupt_in_buffer from ring_buffer into userspace */
494 if (copy_to_user(buffer, actual_buffer+1, bytes_to_read)) {
495 retval = -EFAULT;
496 goto unlock_exit;
497 }
498 dev->ring_tail = (dev->ring_tail+1) % ring_buffer_size;
499
500 retval = bytes_to_read;
501
502 spin_lock_irq(&dev->rbsl);
503 if (dev->buffer_overflow) {
504 dev->buffer_overflow = 0;
505 spin_unlock_irq(&dev->rbsl);
506 rv = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
507 if (rv < 0)
508 dev->buffer_overflow = 1;
509 } else {
510 spin_unlock_irq(&dev->rbsl);
511 }
512
513 unlock_exit:
514 /* unlock the device */
515 mutex_unlock(&dev->mutex);
516
517 exit:
518 return retval;
519 }
520
521 /**
522 * ld_usb_write
523 */
524 static ssize_t ld_usb_write(struct file *file, const char __user *buffer,
525 size_t count, loff_t *ppos)
526 {
527 struct ld_usb *dev;
528 size_t bytes_to_write;
529 int retval = 0;
530
531 dev = file->private_data;
532
533 /* verify that we actually have some data to write */
534 if (count == 0)
535 goto exit;
536
537 /* lock this object */
538 if (mutex_lock_interruptible(&dev->mutex)) {
539 retval = -ERESTARTSYS;
540 goto exit;
541 }
542
543 /* verify that the device wasn't unplugged */
544 if (dev->intf == NULL) {
545 retval = -ENODEV;
546 printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval);
547 goto unlock_exit;
548 }
549
550 /* wait until previous transfer is finished */
551 if (dev->interrupt_out_busy) {
552 if (file->f_flags & O_NONBLOCK) {
553 retval = -EAGAIN;
554 goto unlock_exit;
555 }
556 retval = wait_event_interruptible(dev->write_wait, !dev->interrupt_out_busy);
557 if (retval < 0) {
558 goto unlock_exit;
559 }
560 }
561
562 /* write the data into interrupt_out_buffer from userspace */
563 bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size);
564 if (bytes_to_write < count)
565 dev_warn(&dev->intf->dev, "Write buffer overflow, %zd bytes dropped\n", count-bytes_to_write);
566 dev_dbg(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\n",
567 __func__, count, bytes_to_write);
568
569 if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
570 retval = -EFAULT;
571 goto unlock_exit;
572 }
573
574 if (dev->interrupt_out_endpoint == NULL) {
575 /* try HID_REQ_SET_REPORT=9 on control_endpoint instead of interrupt_out_endpoint */
576 retval = usb_control_msg(interface_to_usbdev(dev->intf),
577 usb_sndctrlpipe(interface_to_usbdev(dev->intf), 0),
578 9,
579 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
580 1 << 8, 0,
581 dev->interrupt_out_buffer,
582 bytes_to_write,
583 USB_CTRL_SET_TIMEOUT * HZ);
584 if (retval < 0)
585 dev_err(&dev->intf->dev,
586 "Couldn't submit HID_REQ_SET_REPORT %d\n",
587 retval);
588 goto unlock_exit;
589 }
590
591 /* send off the urb */
592 usb_fill_int_urb(dev->interrupt_out_urb,
593 interface_to_usbdev(dev->intf),
594 usb_sndintpipe(interface_to_usbdev(dev->intf),
595 dev->interrupt_out_endpoint->bEndpointAddress),
596 dev->interrupt_out_buffer,
597 bytes_to_write,
598 ld_usb_interrupt_out_callback,
599 dev,
600 dev->interrupt_out_interval);
601
602 dev->interrupt_out_busy = 1;
603 wmb();
604
605 retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
606 if (retval) {
607 dev->interrupt_out_busy = 0;
608 dev_err(&dev->intf->dev,
609 "Couldn't submit interrupt_out_urb %d\n", retval);
610 goto unlock_exit;
611 }
612 retval = bytes_to_write;
613
614 unlock_exit:
615 /* unlock the device */
616 mutex_unlock(&dev->mutex);
617
618 exit:
619 return retval;
620 }
621
622 /* file operations needed when we register this driver */
623 static const struct file_operations ld_usb_fops = {
624 .owner = THIS_MODULE,
625 .read = ld_usb_read,
626 .write = ld_usb_write,
627 .open = ld_usb_open,
628 .release = ld_usb_release,
629 .poll = ld_usb_poll,
630 .llseek = no_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 the driver core
636 */
637 static struct usb_class_driver ld_usb_class = {
638 .name = "ldusb%d",
639 .fops = &ld_usb_fops,
640 .minor_base = USB_LD_MINOR_BASE,
641 };
642
643 /**
644 * ld_usb_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 ld_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
650 {
651 struct usb_device *udev = interface_to_usbdev(intf);
652 struct ld_usb *dev = NULL;
653 struct usb_host_interface *iface_desc;
654 char *buffer;
655 int retval = -ENOMEM;
656 int res;
657
658 /* allocate memory for our device state and initialize it */
659
660 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
661 if (!dev)
662 goto exit;
663 mutex_init(&dev->mutex);
664 spin_lock_init(&dev->rbsl);
665 dev->intf = intf;
666 init_waitqueue_head(&dev->read_wait);
667 init_waitqueue_head(&dev->write_wait);
668
669 /* workaround for early firmware versions on fast computers */
670 if ((le16_to_cpu(udev->descriptor.idVendor) == USB_VENDOR_ID_LD) &&
671 ((le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_CASSY) ||
672 (le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_COM3LAB)) &&
673 (le16_to_cpu(udev->descriptor.bcdDevice) <= 0x103)) {
674 buffer = kmalloc(256, GFP_KERNEL);
675 if (!buffer)
676 goto error;
677 /* usb_string makes SETUP+STALL to leave always ControlReadLoop */
678 usb_string(udev, 255, buffer, 256);
679 kfree(buffer);
680 }
681
682 iface_desc = intf->cur_altsetting;
683
684 res = usb_find_last_int_in_endpoint(iface_desc,
685 &dev->interrupt_in_endpoint);
686 if (res) {
687 dev_err(&intf->dev, "Interrupt in endpoint not found\n");
688 retval = res;
689 goto error;
690 }
691
692 res = usb_find_last_int_out_endpoint(iface_desc,
693 &dev->interrupt_out_endpoint);
694 if (res)
695 dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n");
696
697 dev->interrupt_in_endpoint_size = usb_endpoint_maxp(dev->interrupt_in_endpoint);
698 dev->ring_buffer = kmalloc(ring_buffer_size*(sizeof(size_t)+dev->interrupt_in_endpoint_size), GFP_KERNEL);
699 if (!dev->ring_buffer)
700 goto error;
701 dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
702 if (!dev->interrupt_in_buffer)
703 goto error;
704 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
705 if (!dev->interrupt_in_urb)
706 goto error;
707 dev->interrupt_out_endpoint_size = dev->interrupt_out_endpoint ? usb_endpoint_maxp(dev->interrupt_out_endpoint) :
708 udev->descriptor.bMaxPacketSize0;
709 dev->interrupt_out_buffer = kmalloc(write_buffer_size*dev->interrupt_out_endpoint_size, GFP_KERNEL);
710 if (!dev->interrupt_out_buffer)
711 goto error;
712 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
713 if (!dev->interrupt_out_urb)
714 goto error;
715 dev->interrupt_in_interval = min_interrupt_in_interval > dev->interrupt_in_endpoint->bInterval ? min_interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
716 if (dev->interrupt_out_endpoint)
717 dev->interrupt_out_interval = min_interrupt_out_interval > dev->interrupt_out_endpoint->bInterval ? min_interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
718
719 /* we can register the device now, as it is ready */
720 usb_set_intfdata(intf, dev);
721
722 retval = usb_register_dev(intf, &ld_usb_class);
723 if (retval) {
724 /* something prevented us from registering this driver */
725 dev_err(&intf->dev, "Not able to get a minor for this device.\n");
726 usb_set_intfdata(intf, NULL);
727 goto error;
728 }
729
730 /* let the user know what node this device is now attached to */
731 dev_info(&intf->dev, "LD USB Device #%d now attached to major %d minor %d\n",
732 (intf->minor - USB_LD_MINOR_BASE), USB_MAJOR, intf->minor);
733
734 exit:
735 return retval;
736
737 error:
738 ld_usb_delete(dev);
739
740 return retval;
741 }
742
743 /**
744 * ld_usb_disconnect
745 *
746 * Called by the usb core when the device is removed from the system.
747 */
748 static void ld_usb_disconnect(struct usb_interface *intf)
749 {
750 struct ld_usb *dev;
751 int minor;
752
753 dev = usb_get_intfdata(intf);
754 usb_set_intfdata(intf, NULL);
755
756 minor = intf->minor;
757
758 /* give back our minor */
759 usb_deregister_dev(intf, &ld_usb_class);
760
761 mutex_lock(&dev->mutex);
762
763 /* if the device is not opened, then we clean up right now */
764 if (!dev->open_count) {
765 mutex_unlock(&dev->mutex);
766 ld_usb_delete(dev);
767 } else {
768 dev->intf = NULL;
769 /* wake up pollers */
770 wake_up_interruptible_all(&dev->read_wait);
771 wake_up_interruptible_all(&dev->write_wait);
772 mutex_unlock(&dev->mutex);
773 }
774
775 dev_info(&intf->dev, "LD USB Device #%d now disconnected\n",
776 (minor - USB_LD_MINOR_BASE));
777 }
778
779 /* usb specific object needed to register this driver with the usb subsystem */
780 static struct usb_driver ld_usb_driver = {
781 .name = "ldusb",
782 .probe = ld_usb_probe,
783 .disconnect = ld_usb_disconnect,
784 .id_table = ld_usb_table,
785 };
786
787 module_usb_driver(ld_usb_driver);
788
Linux with added FPC-III support