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Linux 4.19-rc7
[linux-2.6/btrfs-unstable.git] / drivers / usb / misc / ldusb.c
blob006762b72ff54211f05fed030170bc7f1a70448d
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 unsigned long flags;
229 int retval;
230
231 if (status) {
232 if (status == -ENOENT ||
233 status == -ECONNRESET ||
234 status == -ESHUTDOWN) {
235 goto exit;
236 } else {
237 dev_dbg(&dev->intf->dev,
238 "%s: nonzero status received: %d\n", __func__,
239 status);
240 spin_lock_irqsave(&dev->rbsl, flags);
241 goto resubmit; /* maybe we can recover */
242 }
243 }
244
245 spin_lock_irqsave(&dev->rbsl, flags);
246 if (urb->actual_length > 0) {
247 next_ring_head = (dev->ring_head+1) % ring_buffer_size;
248 if (next_ring_head != dev->ring_tail) {
249 actual_buffer = (size_t *)(dev->ring_buffer + dev->ring_head * (sizeof(size_t)+dev->interrupt_in_endpoint_size));
250 /* actual_buffer gets urb->actual_length + interrupt_in_buffer */
251 *actual_buffer = urb->actual_length;
252 memcpy(actual_buffer+1, dev->interrupt_in_buffer, urb->actual_length);
253 dev->ring_head = next_ring_head;
254 dev_dbg(&dev->intf->dev, "%s: received %d bytes\n",
255 __func__, urb->actual_length);
256 } else {
257 dev_warn(&dev->intf->dev,
258 "Ring buffer overflow, %d bytes dropped\n",
259 urb->actual_length);
260 dev->buffer_overflow = 1;
261 }
262 }
263
264 resubmit:
265 /* resubmit if we're still running */
266 if (dev->interrupt_in_running && !dev->buffer_overflow && dev->intf) {
267 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_ATOMIC);
268 if (retval) {
269 dev_err(&dev->intf->dev,
270 "usb_submit_urb failed (%d)\n", retval);
271 dev->buffer_overflow = 1;
272 }
273 }
274 spin_unlock_irqrestore(&dev->rbsl, flags);
275 exit:
276 dev->interrupt_in_done = 1;
277 wake_up_interruptible(&dev->read_wait);
278 }
279
280 /**
281 * ld_usb_interrupt_out_callback
282 */
283 static void ld_usb_interrupt_out_callback(struct urb *urb)
284 {
285 struct ld_usb *dev = urb->context;
286 int status = urb->status;
287
288 /* sync/async unlink faults aren't errors */
289 if (status && !(status == -ENOENT ||
290 status == -ECONNRESET ||
291 status == -ESHUTDOWN))
292 dev_dbg(&dev->intf->dev,
293 "%s - nonzero write interrupt status received: %d\n",
294 __func__, status);
295
296 dev->interrupt_out_busy = 0;
297 wake_up_interruptible(&dev->write_wait);
298 }
299
300 /**
301 * ld_usb_open
302 */
303 static int ld_usb_open(struct inode *inode, struct file *file)
304 {
305 struct ld_usb *dev;
306 int subminor;
307 int retval;
308 struct usb_interface *interface;
309
310 nonseekable_open(inode, file);
311 subminor = iminor(inode);
312
313 interface = usb_find_interface(&ld_usb_driver, subminor);
314
315 if (!interface) {
316 printk(KERN_ERR "%s - error, can't find device for minor %d\n",
317 __func__, subminor);
318 return -ENODEV;
319 }
320
321 dev = usb_get_intfdata(interface);
322
323 if (!dev)
324 return -ENODEV;
325
326 /* lock this device */
327 if (mutex_lock_interruptible(&dev->mutex))
328 return -ERESTARTSYS;
329
330 /* allow opening only once */
331 if (dev->open_count) {
332 retval = -EBUSY;
333 goto unlock_exit;
334 }
335 dev->open_count = 1;
336
337 /* initialize in direction */
338 dev->ring_head = 0;
339 dev->ring_tail = 0;
340 dev->buffer_overflow = 0;
341 usb_fill_int_urb(dev->interrupt_in_urb,
342 interface_to_usbdev(interface),
343 usb_rcvintpipe(interface_to_usbdev(interface),
344 dev->interrupt_in_endpoint->bEndpointAddress),
345 dev->interrupt_in_buffer,
346 dev->interrupt_in_endpoint_size,
347 ld_usb_interrupt_in_callback,
348 dev,
349 dev->interrupt_in_interval);
350
351 dev->interrupt_in_running = 1;
352 dev->interrupt_in_done = 0;
353
354 retval = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
355 if (retval) {
356 dev_err(&interface->dev, "Couldn't submit interrupt_in_urb %d\n", retval);
357 dev->interrupt_in_running = 0;
358 dev->open_count = 0;
359 goto unlock_exit;
360 }
361
362 /* save device in the file's private structure */
363 file->private_data = dev;
364
365 unlock_exit:
366 mutex_unlock(&dev->mutex);
367
368 return retval;
369 }
370
371 /**
372 * ld_usb_release
373 */
374 static int ld_usb_release(struct inode *inode, struct file *file)
375 {
376 struct ld_usb *dev;
377 int retval = 0;
378
379 dev = file->private_data;
380
381 if (dev == NULL) {
382 retval = -ENODEV;
383 goto exit;
384 }
385
386 if (mutex_lock_interruptible(&dev->mutex)) {
387 retval = -ERESTARTSYS;
388 goto exit;
389 }
390
391 if (dev->open_count != 1) {
392 retval = -ENODEV;
393 goto unlock_exit;
394 }
395 if (dev->intf == NULL) {
396 /* the device was unplugged before the file was released */
397 mutex_unlock(&dev->mutex);
398 /* unlock here as ld_usb_delete frees dev */
399 ld_usb_delete(dev);
400 goto exit;
401 }
402
403 /* wait until write transfer is finished */
404 if (dev->interrupt_out_busy)
405 wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
406 ld_usb_abort_transfers(dev);
407 dev->open_count = 0;
408
409 unlock_exit:
410 mutex_unlock(&dev->mutex);
411
412 exit:
413 return retval;
414 }
415
416 /**
417 * ld_usb_poll
418 */
419 static __poll_t ld_usb_poll(struct file *file, poll_table *wait)
420 {
421 struct ld_usb *dev;
422 __poll_t mask = 0;
423
424 dev = file->private_data;
425
426 if (!dev->intf)
427 return EPOLLERR | EPOLLHUP;
428
429 poll_wait(file, &dev->read_wait, wait);
430 poll_wait(file, &dev->write_wait, wait);
431
432 if (dev->ring_head != dev->ring_tail)
433 mask |= EPOLLIN | EPOLLRDNORM;
434 if (!dev->interrupt_out_busy)
435 mask |= EPOLLOUT | EPOLLWRNORM;
436
437 return mask;
438 }
439
440 /**
441 * ld_usb_read
442 */
443 static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count,
444 loff_t *ppos)
445 {
446 struct ld_usb *dev;
447 size_t *actual_buffer;
448 size_t bytes_to_read;
449 int retval = 0;
450 int rv;
451
452 dev = file->private_data;
453
454 /* verify that we actually have some data to read */
455 if (count == 0)
456 goto exit;
457
458 /* lock this object */
459 if (mutex_lock_interruptible(&dev->mutex)) {
460 retval = -ERESTARTSYS;
461 goto exit;
462 }
463
464 /* verify that the device wasn't unplugged */
465 if (dev->intf == NULL) {
466 retval = -ENODEV;
467 printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval);
468 goto unlock_exit;
469 }
470
471 /* wait for data */
472 spin_lock_irq(&dev->rbsl);
473 if (dev->ring_head == dev->ring_tail) {
474 dev->interrupt_in_done = 0;
475 spin_unlock_irq(&dev->rbsl);
476 if (file->f_flags & O_NONBLOCK) {
477 retval = -EAGAIN;
478 goto unlock_exit;
479 }
480 retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done);
481 if (retval < 0)
482 goto unlock_exit;
483 } else {
484 spin_unlock_irq(&dev->rbsl);
485 }
486
487 /* actual_buffer contains actual_length + interrupt_in_buffer */
488 actual_buffer = (size_t *)(dev->ring_buffer + dev->ring_tail * (sizeof(size_t)+dev->interrupt_in_endpoint_size));
489 bytes_to_read = min(count, *actual_buffer);
490 if (bytes_to_read < *actual_buffer)
491 dev_warn(&dev->intf->dev, "Read buffer overflow, %zd bytes dropped\n",
492 *actual_buffer-bytes_to_read);
493
494 /* copy one interrupt_in_buffer from ring_buffer into userspace */
495 if (copy_to_user(buffer, actual_buffer+1, bytes_to_read)) {
496 retval = -EFAULT;
497 goto unlock_exit;
498 }
499 dev->ring_tail = (dev->ring_tail+1) % ring_buffer_size;
500
501 retval = bytes_to_read;
502
503 spin_lock_irq(&dev->rbsl);
504 if (dev->buffer_overflow) {
505 dev->buffer_overflow = 0;
506 spin_unlock_irq(&dev->rbsl);
507 rv = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
508 if (rv < 0)
509 dev->buffer_overflow = 1;
510 } else {
511 spin_unlock_irq(&dev->rbsl);
512 }
513
514 unlock_exit:
515 /* unlock the device */
516 mutex_unlock(&dev->mutex);
517
518 exit:
519 return retval;
520 }
521
522 /**
523 * ld_usb_write
524 */
525 static ssize_t ld_usb_write(struct file *file, const char __user *buffer,
526 size_t count, loff_t *ppos)
527 {
528 struct ld_usb *dev;
529 size_t bytes_to_write;
530 int retval = 0;
531
532 dev = file->private_data;
533
534 /* verify that we actually have some data to write */
535 if (count == 0)
536 goto exit;
537
538 /* lock this object */
539 if (mutex_lock_interruptible(&dev->mutex)) {
540 retval = -ERESTARTSYS;
541 goto exit;
542 }
543
544 /* verify that the device wasn't unplugged */
545 if (dev->intf == NULL) {
546 retval = -ENODEV;
547 printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval);
548 goto unlock_exit;
549 }
550
551 /* wait until previous transfer is finished */
552 if (dev->interrupt_out_busy) {
553 if (file->f_flags & O_NONBLOCK) {
554 retval = -EAGAIN;
555 goto unlock_exit;
556 }
557 retval = wait_event_interruptible(dev->write_wait, !dev->interrupt_out_busy);
558 if (retval < 0) {
559 goto unlock_exit;
560 }
561 }
562
563 /* write the data into interrupt_out_buffer from userspace */
564 bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size);
565 if (bytes_to_write < count)
566 dev_warn(&dev->intf->dev, "Write buffer overflow, %zd bytes dropped\n", count-bytes_to_write);
567 dev_dbg(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\n",
568 __func__, count, bytes_to_write);
569
570 if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
571 retval = -EFAULT;
572 goto unlock_exit;
573 }
574
575 if (dev->interrupt_out_endpoint == NULL) {
576 /* try HID_REQ_SET_REPORT=9 on control_endpoint instead of interrupt_out_endpoint */
577 retval = usb_control_msg(interface_to_usbdev(dev->intf),
578 usb_sndctrlpipe(interface_to_usbdev(dev->intf), 0),
579 9,
580 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
581 1 << 8, 0,
582 dev->interrupt_out_buffer,
583 bytes_to_write,
584 USB_CTRL_SET_TIMEOUT * HZ);
585 if (retval < 0)
586 dev_err(&dev->intf->dev,
587 "Couldn't submit HID_REQ_SET_REPORT %d\n",
588 retval);
589 goto unlock_exit;
590 }
591
592 /* send off the urb */
593 usb_fill_int_urb(dev->interrupt_out_urb,
594 interface_to_usbdev(dev->intf),
595 usb_sndintpipe(interface_to_usbdev(dev->intf),
596 dev->interrupt_out_endpoint->bEndpointAddress),
597 dev->interrupt_out_buffer,
598 bytes_to_write,
599 ld_usb_interrupt_out_callback,
600 dev,
601 dev->interrupt_out_interval);
602
603 dev->interrupt_out_busy = 1;
604 wmb();
605
606 retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
607 if (retval) {
608 dev->interrupt_out_busy = 0;
609 dev_err(&dev->intf->dev,
610 "Couldn't submit interrupt_out_urb %d\n", retval);
611 goto unlock_exit;
612 }
613 retval = bytes_to_write;
614
615 unlock_exit:
616 /* unlock the device */
617 mutex_unlock(&dev->mutex);
618
619 exit:
620 return retval;
621 }
622
623 /* file operations needed when we register this driver */
624 static const struct file_operations ld_usb_fops = {
625 .owner = THIS_MODULE,
626 .read = ld_usb_read,
627 .write = ld_usb_write,
628 .open = ld_usb_open,
629 .release = ld_usb_release,
630 .poll = ld_usb_poll,
631 .llseek = no_llseek,
632 };
633
634 /*
635 * usb class driver info in order to get a minor number from the usb core,
636 * and to have the device registered with the driver core
637 */
638 static struct usb_class_driver ld_usb_class = {
639 .name = "ldusb%d",
640 .fops = &ld_usb_fops,
641 .minor_base = USB_LD_MINOR_BASE,
642 };
643
644 /**
645 * ld_usb_probe
646 *
647 * Called by the usb core when a new device is connected that it thinks
648 * this driver might be interested in.
649 */
650 static int ld_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
651 {
652 struct usb_device *udev = interface_to_usbdev(intf);
653 struct ld_usb *dev = NULL;
654 struct usb_host_interface *iface_desc;
655 char *buffer;
656 int retval = -ENOMEM;
657 int res;
658
659 /* allocate memory for our device state and initialize it */
660
661 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
662 if (!dev)
663 goto exit;
664 mutex_init(&dev->mutex);
665 spin_lock_init(&dev->rbsl);
666 dev->intf = intf;
667 init_waitqueue_head(&dev->read_wait);
668 init_waitqueue_head(&dev->write_wait);
669
670 /* workaround for early firmware versions on fast computers */
671 if ((le16_to_cpu(udev->descriptor.idVendor) == USB_VENDOR_ID_LD) &&
672 ((le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_CASSY) ||
673 (le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_COM3LAB)) &&
674 (le16_to_cpu(udev->descriptor.bcdDevice) <= 0x103)) {
675 buffer = kmalloc(256, GFP_KERNEL);
676 if (!buffer)
677 goto error;
678 /* usb_string makes SETUP+STALL to leave always ControlReadLoop */
679 usb_string(udev, 255, buffer, 256);
680 kfree(buffer);
681 }
682
683 iface_desc = intf->cur_altsetting;
684
685 res = usb_find_last_int_in_endpoint(iface_desc,
686 &dev->interrupt_in_endpoint);
687 if (res) {
688 dev_err(&intf->dev, "Interrupt in endpoint not found\n");
689 retval = res;
690 goto error;
691 }
692
693 res = usb_find_last_int_out_endpoint(iface_desc,
694 &dev->interrupt_out_endpoint);
695 if (res)
696 dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n");
697
698 dev->interrupt_in_endpoint_size = usb_endpoint_maxp(dev->interrupt_in_endpoint);
699 dev->ring_buffer =
700 kmalloc_array(ring_buffer_size,
701 sizeof(size_t) + dev->interrupt_in_endpoint_size,
702 GFP_KERNEL);
703 if (!dev->ring_buffer)
704 goto error;
705 dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
706 if (!dev->interrupt_in_buffer)
707 goto error;
708 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
709 if (!dev->interrupt_in_urb)
710 goto error;
711 dev->interrupt_out_endpoint_size = dev->interrupt_out_endpoint ? usb_endpoint_maxp(dev->interrupt_out_endpoint) :
712 udev->descriptor.bMaxPacketSize0;
713 dev->interrupt_out_buffer =
714 kmalloc_array(write_buffer_size,
715 dev->interrupt_out_endpoint_size, GFP_KERNEL);
716 if (!dev->interrupt_out_buffer)
717 goto error;
718 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
719 if (!dev->interrupt_out_urb)
720 goto error;
721 dev->interrupt_in_interval = min_interrupt_in_interval > dev->interrupt_in_endpoint->bInterval ? min_interrupt_in_interval : dev->interrupt_in_endpoint->bInterval;
722 if (dev->interrupt_out_endpoint)
723 dev->interrupt_out_interval = min_interrupt_out_interval > dev->interrupt_out_endpoint->bInterval ? min_interrupt_out_interval : dev->interrupt_out_endpoint->bInterval;
724
725 /* we can register the device now, as it is ready */
726 usb_set_intfdata(intf, dev);
727
728 retval = usb_register_dev(intf, &ld_usb_class);
729 if (retval) {
730 /* something prevented us from registering this driver */
731 dev_err(&intf->dev, "Not able to get a minor for this device.\n");
732 usb_set_intfdata(intf, NULL);
733 goto error;
734 }
735
736 /* let the user know what node this device is now attached to */
737 dev_info(&intf->dev, "LD USB Device #%d now attached to major %d minor %d\n",
738 (intf->minor - USB_LD_MINOR_BASE), USB_MAJOR, intf->minor);
739
740 exit:
741 return retval;
742
743 error:
744 ld_usb_delete(dev);
745
746 return retval;
747 }
748
749 /**
750 * ld_usb_disconnect
751 *
752 * Called by the usb core when the device is removed from the system.
753 */
754 static void ld_usb_disconnect(struct usb_interface *intf)
755 {
756 struct ld_usb *dev;
757 int minor;
758
759 dev = usb_get_intfdata(intf);
760 usb_set_intfdata(intf, NULL);
761
762 minor = intf->minor;
763
764 /* give back our minor */
765 usb_deregister_dev(intf, &ld_usb_class);
766
767 mutex_lock(&dev->mutex);
768
769 /* if the device is not opened, then we clean up right now */
770 if (!dev->open_count) {
771 mutex_unlock(&dev->mutex);
772 ld_usb_delete(dev);
773 } else {
774 dev->intf = NULL;
775 /* wake up pollers */
776 wake_up_interruptible_all(&dev->read_wait);
777 wake_up_interruptible_all(&dev->write_wait);
778 mutex_unlock(&dev->mutex);
779 }
780
781 dev_info(&intf->dev, "LD USB Device #%d now disconnected\n",
782 (minor - USB_LD_MINOR_BASE));
783 }
784
785 /* usb specific object needed to register this driver with the usb subsystem */
786 static struct usb_driver ld_usb_driver = {
787 .name = "ldusb",
788 .probe = ld_usb_probe,
789 .disconnect = ld_usb_disconnect,
790 .id_table = ld_usb_table,
791 };
792
793 module_usb_driver(ld_usb_driver);
794
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