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Linux 6.13-rc6
[linux.git] / drivers / usb / misc / ldusb.c
blobf392d6f84df9c3ae737b8b23866258c8075acc31
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
121 /* All interrupt in transfers are collected in a ring buffer to
122 * avoid racing conditions and get better performance of the driver.
123 */
124 static int ring_buffer_size = 128;
125 module_param(ring_buffer_size, int, 0000);
126 MODULE_PARM_DESC(ring_buffer_size, "Read ring buffer size in reports");
127
128 /* The write_buffer can contain more than one interrupt out transfer.
129 */
130 static int write_buffer_size = 10;
131 module_param(write_buffer_size, int, 0000);
132 MODULE_PARM_DESC(write_buffer_size, "Write buffer size in reports");
133
134 /* As of kernel version 2.6.4 ehci-hcd uses an
135 * "only one interrupt transfer per frame" shortcut
136 * to simplify the scheduling of periodic transfers.
137 * This conflicts with our standard 1ms intervals for in and out URBs.
138 * We use default intervals of 2ms for in and 2ms for out transfers,
139 * which should be fast enough.
140 * Increase the interval to allow more devices that do interrupt transfers,
141 * or set to 1 to use the standard interval from the endpoint descriptors.
142 */
143 static int min_interrupt_in_interval = 2;
144 module_param(min_interrupt_in_interval, int, 0000);
145 MODULE_PARM_DESC(min_interrupt_in_interval, "Minimum interrupt in interval in ms");
146
147 static int min_interrupt_out_interval = 2;
148 module_param(min_interrupt_out_interval, int, 0000);
149 MODULE_PARM_DESC(min_interrupt_out_interval, "Minimum interrupt out interval in ms");
150
151 /* Structure to hold all of our device specific stuff */
152 struct ld_usb {
153 struct mutex mutex; /* locks this structure */
154 struct usb_interface *intf; /* save off the usb interface pointer */
155 unsigned long disconnected:1;
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 usb_kill_urb(dev->interrupt_in_urb);
196 }
197 if (dev->interrupt_out_busy)
198 usb_kill_urb(dev->interrupt_out_urb);
199 }
200
201 /*
202 * ld_usb_delete
203 */
204 static void ld_usb_delete(struct ld_usb *dev)
205 {
206 /* free data structures */
207 usb_free_urb(dev->interrupt_in_urb);
208 usb_free_urb(dev->interrupt_out_urb);
209 kfree(dev->ring_buffer);
210 kfree(dev->interrupt_in_buffer);
211 kfree(dev->interrupt_out_buffer);
212 kfree(dev);
213 }
214
215 /*
216 * ld_usb_interrupt_in_callback
217 */
218 static void ld_usb_interrupt_in_callback(struct urb *urb)
219 {
220 struct ld_usb *dev = urb->context;
221 size_t *actual_buffer;
222 unsigned int next_ring_head;
223 int status = urb->status;
224 unsigned long flags;
225 int retval;
226
227 if (status) {
228 if (status == -ENOENT ||
229 status == -ECONNRESET ||
230 status == -ESHUTDOWN) {
231 goto exit;
232 } else {
233 dev_dbg(&dev->intf->dev,
234 "%s: nonzero status received: %d\n", __func__,
235 status);
236 spin_lock_irqsave(&dev->rbsl, flags);
237 goto resubmit; /* maybe we can recover */
238 }
239 }
240
241 spin_lock_irqsave(&dev->rbsl, flags);
242 if (urb->actual_length > 0) {
243 next_ring_head = (dev->ring_head+1) % ring_buffer_size;
244 if (next_ring_head != dev->ring_tail) {
245 actual_buffer = (size_t *)(dev->ring_buffer + dev->ring_head * (sizeof(size_t)+dev->interrupt_in_endpoint_size));
246 /* actual_buffer gets urb->actual_length + interrupt_in_buffer */
247 *actual_buffer = urb->actual_length;
248 memcpy(actual_buffer+1, dev->interrupt_in_buffer, urb->actual_length);
249 dev->ring_head = next_ring_head;
250 dev_dbg(&dev->intf->dev, "%s: received %d bytes\n",
251 __func__, urb->actual_length);
252 } else {
253 dev_warn(&dev->intf->dev,
254 "Ring buffer overflow, %d bytes dropped\n",
255 urb->actual_length);
256 dev->buffer_overflow = 1;
257 }
258 }
259
260 resubmit:
261 /* resubmit if we're still running */
262 if (dev->interrupt_in_running && !dev->buffer_overflow) {
263 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
264 if (retval) {
265 dev_err(&dev->intf->dev,
266 "usb_submit_urb failed (%d)\n", retval);
267 dev->buffer_overflow = 1;
268 }
269 }
270 spin_unlock_irqrestore(&dev->rbsl, flags);
271 exit:
272 dev->interrupt_in_done = 1;
273 wake_up_interruptible(&dev->read_wait);
274 }
275
276 /*
277 * ld_usb_interrupt_out_callback
278 */
279 static void ld_usb_interrupt_out_callback(struct urb *urb)
280 {
281 struct ld_usb *dev = urb->context;
282 int status = urb->status;
283
284 /* sync/async unlink faults aren't errors */
285 if (status && !(status == -ENOENT ||
286 status == -ECONNRESET ||
287 status == -ESHUTDOWN))
288 dev_dbg(&dev->intf->dev,
289 "%s - nonzero write interrupt status received: %d\n",
290 __func__, status);
291
292 dev->interrupt_out_busy = 0;
293 wake_up_interruptible(&dev->write_wait);
294 }
295
296 /*
297 * ld_usb_open
298 */
299 static int ld_usb_open(struct inode *inode, struct file *file)
300 {
301 struct ld_usb *dev;
302 int subminor;
303 int retval;
304 struct usb_interface *interface;
305
306 stream_open(inode, file);
307 subminor = iminor(inode);
308
309 interface = usb_find_interface(&ld_usb_driver, subminor);
310
311 if (!interface) {
312 printk(KERN_ERR "%s - error, can't find device for minor %d\n",
313 __func__, subminor);
314 return -ENODEV;
315 }
316
317 dev = usb_get_intfdata(interface);
318
319 if (!dev)
320 return -ENODEV;
321
322 /* lock this device */
323 if (mutex_lock_interruptible(&dev->mutex))
324 return -ERESTARTSYS;
325
326 /* allow opening only once */
327 if (dev->open_count) {
328 retval = -EBUSY;
329 goto unlock_exit;
330 }
331 dev->open_count = 1;
332
333 /* initialize in direction */
334 dev->ring_head = 0;
335 dev->ring_tail = 0;
336 dev->buffer_overflow = 0;
337 usb_fill_int_urb(dev->interrupt_in_urb,
338 interface_to_usbdev(interface),
339 usb_rcvintpipe(interface_to_usbdev(interface),
340 dev->interrupt_in_endpoint->bEndpointAddress),
341 dev->interrupt_in_buffer,
342 dev->interrupt_in_endpoint_size,
343 ld_usb_interrupt_in_callback,
344 dev,
345 dev->interrupt_in_interval);
346
347 dev->interrupt_in_running = 1;
348 dev->interrupt_in_done = 0;
349
350 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
351 if (retval) {
352 dev_err(&interface->dev, "Couldn't submit interrupt_in_urb %d\n", retval);
353 dev->interrupt_in_running = 0;
354 dev->open_count = 0;
355 goto unlock_exit;
356 }
357
358 /* save device in the file's private structure */
359 file->private_data = dev;
360
361 unlock_exit:
362 mutex_unlock(&dev->mutex);
363
364 return retval;
365 }
366
367 /*
368 * ld_usb_release
369 */
370 static int ld_usb_release(struct inode *inode, struct file *file)
371 {
372 struct ld_usb *dev;
373 int retval = 0;
374
375 dev = file->private_data;
376
377 if (dev == NULL) {
378 retval = -ENODEV;
379 goto exit;
380 }
381
382 mutex_lock(&dev->mutex);
383
384 if (dev->open_count != 1) {
385 retval = -ENODEV;
386 goto unlock_exit;
387 }
388 if (dev->disconnected) {
389 /* the device was unplugged before the file was released */
390 mutex_unlock(&dev->mutex);
391 /* unlock here as ld_usb_delete frees dev */
392 ld_usb_delete(dev);
393 goto exit;
394 }
395
396 /* wait until write transfer is finished */
397 if (dev->interrupt_out_busy)
398 wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
399 ld_usb_abort_transfers(dev);
400 dev->open_count = 0;
401
402 unlock_exit:
403 mutex_unlock(&dev->mutex);
404
405 exit:
406 return retval;
407 }
408
409 /*
410 * ld_usb_poll
411 */
412 static __poll_t ld_usb_poll(struct file *file, poll_table *wait)
413 {
414 struct ld_usb *dev;
415 __poll_t mask = 0;
416
417 dev = file->private_data;
418
419 if (dev->disconnected)
420 return EPOLLERR | EPOLLHUP;
421
422 poll_wait(file, &dev->read_wait, wait);
423 poll_wait(file, &dev->write_wait, wait);
424
425 if (dev->ring_head != dev->ring_tail)
426 mask |= EPOLLIN | EPOLLRDNORM;
427 if (!dev->interrupt_out_busy)
428 mask |= EPOLLOUT | EPOLLWRNORM;
429
430 return mask;
431 }
432
433 /*
434 * ld_usb_read
435 */
436 static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count,
437 loff_t *ppos)
438 {
439 struct ld_usb *dev;
440 size_t *actual_buffer;
441 size_t bytes_to_read;
442 int retval = 0;
443 int rv;
444
445 dev = file->private_data;
446
447 /* verify that we actually have some data to read */
448 if (count == 0)
449 goto exit;
450
451 /* lock this object */
452 if (mutex_lock_interruptible(&dev->mutex)) {
453 retval = -ERESTARTSYS;
454 goto exit;
455 }
456
457 /* verify that the device wasn't unplugged */
458 if (dev->disconnected) {
459 retval = -ENODEV;
460 printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval);
461 goto unlock_exit;
462 }
463
464 /* wait for data */
465 spin_lock_irq(&dev->rbsl);
466 while (dev->ring_head == dev->ring_tail) {
467 dev->interrupt_in_done = 0;
468 spin_unlock_irq(&dev->rbsl);
469 if (file->f_flags & O_NONBLOCK) {
470 retval = -EAGAIN;
471 goto unlock_exit;
472 }
473 retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done);
474 if (retval < 0)
475 goto unlock_exit;
476
477 spin_lock_irq(&dev->rbsl);
478 }
479 spin_unlock_irq(&dev->rbsl);
480
481 /* actual_buffer contains actual_length + interrupt_in_buffer */
482 actual_buffer = (size_t *)(dev->ring_buffer + dev->ring_tail * (sizeof(size_t)+dev->interrupt_in_endpoint_size));
483 if (*actual_buffer > dev->interrupt_in_endpoint_size) {
484 retval = -EIO;
485 goto unlock_exit;
486 }
487 bytes_to_read = min(count, *actual_buffer);
488 if (bytes_to_read < *actual_buffer)
489 dev_warn(&dev->intf->dev, "Read buffer overflow, %zu bytes dropped\n",
490 *actual_buffer-bytes_to_read);
491
492 /* copy one interrupt_in_buffer from ring_buffer into userspace */
493 if (copy_to_user(buffer, actual_buffer+1, bytes_to_read)) {
494 retval = -EFAULT;
495 goto unlock_exit;
496 }
497 retval = bytes_to_read;
498
499 spin_lock_irq(&dev->rbsl);
500 dev->ring_tail = (dev->ring_tail + 1) % ring_buffer_size;
501
502 if (dev->buffer_overflow) {
503 dev->buffer_overflow = 0;
504 spin_unlock_irq(&dev->rbsl);
505 rv = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
506 if (rv < 0)
507 dev->buffer_overflow = 1;
508 } else {
509 spin_unlock_irq(&dev->rbsl);
510 }
511
512 unlock_exit:
513 /* unlock the device */
514 mutex_unlock(&dev->mutex);
515
516 exit:
517 return retval;
518 }
519
520 /*
521 * ld_usb_write
522 */
523 static ssize_t ld_usb_write(struct file *file, const char __user *buffer,
524 size_t count, loff_t *ppos)
525 {
526 struct ld_usb *dev;
527 size_t bytes_to_write;
528 int retval = 0;
529
530 dev = file->private_data;
531
532 /* verify that we actually have some data to write */
533 if (count == 0)
534 goto exit;
535
536 /* lock this object */
537 if (mutex_lock_interruptible(&dev->mutex)) {
538 retval = -ERESTARTSYS;
539 goto exit;
540 }
541
542 /* verify that the device wasn't unplugged */
543 if (dev->disconnected) {
544 retval = -ENODEV;
545 printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval);
546 goto unlock_exit;
547 }
548
549 /* wait until previous transfer is finished */
550 if (dev->interrupt_out_busy) {
551 if (file->f_flags & O_NONBLOCK) {
552 retval = -EAGAIN;
553 goto unlock_exit;
554 }
555 retval = wait_event_interruptible(dev->write_wait, !dev->interrupt_out_busy);
556 if (retval < 0) {
557 goto unlock_exit;
558 }
559 }
560
561 /* write the data into interrupt_out_buffer from userspace */
562 bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size);
563 if (bytes_to_write < count)
564 dev_warn(&dev->intf->dev, "Write buffer overflow, %zu bytes dropped\n",
565 count - bytes_to_write);
566 dev_dbg(&dev->intf->dev, "%s: count = %zu, bytes_to_write = %zu\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);
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 };
631
632 /*
633 * usb class driver info in order to get a minor number from the usb core,
634 * and to have the device registered with the driver core
635 */
636 static struct usb_class_driver ld_usb_class = {
637 .name = "ldusb%d",
638 .fops = &ld_usb_fops,
639 .minor_base = USB_LD_MINOR_BASE,
640 };
641
642 /*
643 * ld_usb_probe
644 *
645 * Called by the usb core when a new device is connected that it thinks
646 * this driver might be interested in.
647 */
648 static int ld_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
649 {
650 struct usb_device *udev = interface_to_usbdev(intf);
651 struct ld_usb *dev = NULL;
652 struct usb_host_interface *iface_desc;
653 char *buffer;
654 int retval = -ENOMEM;
655 int res;
656
657 /* allocate memory for our device state and initialize it */
658
659 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
660 if (!dev)
661 goto exit;
662 mutex_init(&dev->mutex);
663 spin_lock_init(&dev->rbsl);
664 dev->intf = intf;
665 init_waitqueue_head(&dev->read_wait);
666 init_waitqueue_head(&dev->write_wait);
667
668 /* workaround for early firmware versions on fast computers */
669 if ((le16_to_cpu(udev->descriptor.idVendor) == USB_VENDOR_ID_LD) &&
670 ((le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_CASSY) ||
671 (le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_COM3LAB)) &&
672 (le16_to_cpu(udev->descriptor.bcdDevice) <= 0x103)) {
673 buffer = kmalloc(256, GFP_KERNEL);
674 if (!buffer)
675 goto error;
676 /* usb_string makes SETUP+STALL to leave always ControlReadLoop */
677 usb_string(udev, 255, buffer, 256);
678 kfree(buffer);
679 }
680
681 iface_desc = intf->cur_altsetting;
682
683 res = usb_find_last_int_in_endpoint(iface_desc,
684 &dev->interrupt_in_endpoint);
685 if (res) {
686 dev_err(&intf->dev, "Interrupt in endpoint not found\n");
687 retval = res;
688 goto error;
689 }
690
691 res = usb_find_last_int_out_endpoint(iface_desc,
692 &dev->interrupt_out_endpoint);
693 if (res)
694 dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n");
695
696 dev->interrupt_in_endpoint_size = usb_endpoint_maxp(dev->interrupt_in_endpoint);
697 dev->ring_buffer = kcalloc(ring_buffer_size,
698 sizeof(size_t) + dev->interrupt_in_endpoint_size,
699 GFP_KERNEL);
700 if (!dev->ring_buffer)
701 goto error;
702 dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
703 if (!dev->interrupt_in_buffer)
704 goto error;
705 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
706 if (!dev->interrupt_in_urb)
707 goto error;
708 dev->interrupt_out_endpoint_size = dev->interrupt_out_endpoint ? usb_endpoint_maxp(dev->interrupt_out_endpoint) :
709 udev->descriptor.bMaxPacketSize0;
710 dev->interrupt_out_buffer =
711 kmalloc_array(write_buffer_size,
712 dev->interrupt_out_endpoint_size, GFP_KERNEL);
713 if (!dev->interrupt_out_buffer)
714 goto error;
715 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
716 if (!dev->interrupt_out_urb)
717 goto error;
718 dev->interrupt_in_interval = max_t(int, min_interrupt_in_interval,
719 dev->interrupt_in_endpoint->bInterval);
720 if (dev->interrupt_out_endpoint)
721 dev->interrupt_out_interval = max_t(int, min_interrupt_out_interval,
722 dev->interrupt_out_endpoint->bInterval);
723
724 /* we can register the device now, as it is ready */
725 usb_set_intfdata(intf, dev);
726
727 retval = usb_register_dev(intf, &ld_usb_class);
728 if (retval) {
729 /* something prevented us from registering this driver */
730 dev_err(&intf->dev, "Not able to get a minor for this device.\n");
731 usb_set_intfdata(intf, NULL);
732 goto error;
733 }
734
735 /* let the user know what node this device is now attached to */
736 dev_info(&intf->dev, "LD USB Device #%d now attached to major %d minor %d\n",
737 (intf->minor - USB_LD_MINOR_BASE), USB_MAJOR, intf->minor);
738
739 exit:
740 return retval;
741
742 error:
743 ld_usb_delete(dev);
744
745 return retval;
746 }
747
748 /*
749 * ld_usb_disconnect
750 *
751 * Called by the usb core when the device is removed from the system.
752 */
753 static void ld_usb_disconnect(struct usb_interface *intf)
754 {
755 struct ld_usb *dev;
756 int minor;
757
758 dev = usb_get_intfdata(intf);
759 usb_set_intfdata(intf, NULL);
760
761 minor = intf->minor;
762
763 /* give back our minor */
764 usb_deregister_dev(intf, &ld_usb_class);
765
766 usb_poison_urb(dev->interrupt_in_urb);
767 usb_poison_urb(dev->interrupt_out_urb);
768
769 mutex_lock(&dev->mutex);
770
771 /* if the device is not opened, then we clean up right now */
772 if (!dev->open_count) {
773 mutex_unlock(&dev->mutex);
774 ld_usb_delete(dev);
775 } else {
776 dev->disconnected = 1;
777 /* wake up pollers */
778 wake_up_interruptible_all(&dev->read_wait);
779 wake_up_interruptible_all(&dev->write_wait);
780 mutex_unlock(&dev->mutex);
781 }
782
783 dev_info(&intf->dev, "LD USB Device #%d now disconnected\n",
784 (minor - USB_LD_MINOR_BASE));
785 }
786
787 /* usb specific object needed to register this driver with the usb subsystem */
788 static struct usb_driver ld_usb_driver = {
789 .name = "ldusb",
790 .probe = ld_usb_probe,
791 .disconnect = ld_usb_disconnect,
792 .id_table = ld_usb_table,
793 };
794
795 module_usb_driver(ld_usb_driver);
796
Linux Kernel