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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 <[email protected]>
15 *
16 * Derived from Lego USB Tower driver
17 * Copyright (C) 2003 David Glance <[email protected]>
18 * 2001-2004 Juergen Stuber <[email protected]>
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 */
78static 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};
116MODULE_DEVICE_TABLE(usb, ld_usb_table);
117MODULE_AUTHOR("Michael Hund <[email protected]>");
118MODULE_DESCRIPTION("LD USB Driver");
119MODULE_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 */
124static int ring_buffer_size = 128;
125module_param(ring_buffer_size, int, 0000);
126MODULE_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 */
130static int write_buffer_size = 10;
131module_param(write_buffer_size, int, 0000);
132MODULE_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 */
143static int min_interrupt_in_interval = 2;
144module_param(min_interrupt_in_interval, int, 0000);
145MODULE_PARM_DESC(min_interrupt_in_interval, "Minimum interrupt in interval in ms");
146
147static int min_interrupt_out_interval = 2;
148module_param(min_interrupt_out_interval, int, 0000);
149MODULE_PARM_DESC(min_interrupt_out_interval, "Minimum interrupt out interval in ms");
150
151/* Structure to hold all of our device specific stuff */
152struct ld_usb {
153 struct kref kref;
154 struct mutex mutex; /* locks this structure */
155 struct usb_interface *intf; /* save off the usb interface pointer */
156 unsigned long disconnected:1;
157
158 int open_count; /* number of times this port has been opened */
159
160 char *ring_buffer;
161 unsigned int ring_head;
162 unsigned int ring_tail;
163
164 wait_queue_head_t read_wait;
165 wait_queue_head_t write_wait;
166
167 char *interrupt_in_buffer;
168 struct usb_endpoint_descriptor *interrupt_in_endpoint;
169 struct urb *interrupt_in_urb;
170 int interrupt_in_interval;
171 size_t interrupt_in_endpoint_size;
172 int interrupt_in_running;
173 int interrupt_in_done;
174 int buffer_overflow;
175 spinlock_t rbsl;
176
177 char *interrupt_out_buffer;
178 struct usb_endpoint_descriptor *interrupt_out_endpoint;
179 struct urb *interrupt_out_urb;
180 int interrupt_out_interval;
181 size_t interrupt_out_endpoint_size;
182 int interrupt_out_busy;
183};
184
185static struct usb_driver ld_usb_driver;
186
187/*
188 * ld_usb_abort_transfers
189 * aborts transfers and frees associated data structures
190 */
191static void ld_usb_abort_transfers(struct ld_usb *dev)
192{
193 /* shutdown transfer */
194 if (dev->interrupt_in_running) {
195 dev->interrupt_in_running = 0;
196 usb_kill_urb(dev->interrupt_in_urb);
197 }
198 if (dev->interrupt_out_busy)
199 usb_kill_urb(dev->interrupt_out_urb);
200}
201
202/*
203 * ld_usb_delete
204 */
205static void ld_usb_delete(struct kref *kref)
206{
207 struct ld_usb *dev = container_of(kref, struct ld_usb, kref);
208
209 /* free data structures */
210 usb_free_urb(dev->interrupt_in_urb);
211 usb_free_urb(dev->interrupt_out_urb);
212 kfree(dev->ring_buffer);
213 kfree(dev->interrupt_in_buffer);
214 kfree(dev->interrupt_out_buffer);
215 kfree(dev);
216}
217
218/*
219 * ld_usb_interrupt_in_callback
220 */
221static void ld_usb_interrupt_in_callback(struct urb *urb)
222{
223 struct ld_usb *dev = urb->context;
224 size_t *actual_buffer;
225 unsigned int next_ring_head;
226 int status = urb->status;
227 unsigned long flags;
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_irqsave(&dev->rbsl, flags);
240 goto resubmit; /* maybe we can recover */
241 }
242 }
243
244 spin_lock_irqsave(&dev->rbsl, flags);
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
263resubmit:
264 /* resubmit if we're still running */
265 if (dev->interrupt_in_running && !dev->buffer_overflow) {
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_irqrestore(&dev->rbsl, flags);
274exit:
275 dev->interrupt_in_done = 1;
276 wake_up_interruptible(&dev->read_wait);
277}
278
279/*
280 * ld_usb_interrupt_out_callback
281 */
282static 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 */
302static 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 stream_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 kref_get(&dev->kref);
362
363 /* save device in the file's private structure */
364 file->private_data = dev;
365
366unlock_exit:
367 mutex_unlock(&dev->mutex);
368
369 return retval;
370}
371
372/*
373 * ld_usb_release
374 */
375static int ld_usb_release(struct inode *inode, struct file *file)
376{
377 struct ld_usb *dev;
378 int retval = 0;
379
380 dev = file->private_data;
381
382 if (dev == NULL) {
383 retval = -ENODEV;
384 goto exit;
385 }
386
387 mutex_lock(&dev->mutex);
388
389 if (dev->disconnected)
390 goto unlock_exit;
391
392 /* wait until write transfer is finished */
393 if (dev->interrupt_out_busy)
394 wait_event_interruptible_timeout(dev->write_wait, !dev->interrupt_out_busy, 2 * HZ);
395 ld_usb_abort_transfers(dev);
396 dev->open_count = 0;
397
398unlock_exit:
399 mutex_unlock(&dev->mutex);
400 kref_put(&dev->kref, ld_usb_delete);
401exit:
402 return retval;
403}
404
405/*
406 * ld_usb_poll
407 */
408static __poll_t ld_usb_poll(struct file *file, poll_table *wait)
409{
410 struct ld_usb *dev;
411 __poll_t mask = 0;
412
413 dev = file->private_data;
414
415 if (dev->disconnected)
416 return EPOLLERR | EPOLLHUP;
417
418 poll_wait(file, &dev->read_wait, wait);
419 poll_wait(file, &dev->write_wait, wait);
420
421 if (dev->ring_head != dev->ring_tail)
422 mask |= EPOLLIN | EPOLLRDNORM;
423 if (!dev->interrupt_out_busy)
424 mask |= EPOLLOUT | EPOLLWRNORM;
425
426 return mask;
427}
428
429/*
430 * ld_usb_read
431 */
432static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count,
433 loff_t *ppos)
434{
435 struct ld_usb *dev;
436 size_t *actual_buffer;
437 size_t bytes_to_read;
438 int retval = 0;
439 int rv;
440
441 dev = file->private_data;
442
443 /* verify that we actually have some data to read */
444 if (count == 0)
445 goto exit;
446
447 /* lock this object */
448 if (mutex_lock_interruptible(&dev->mutex)) {
449 retval = -ERESTARTSYS;
450 goto exit;
451 }
452
453 /* verify that the device wasn't unplugged */
454 if (dev->disconnected) {
455 retval = -ENODEV;
456 printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval);
457 goto unlock_exit;
458 }
459
460 /* wait for data */
461 spin_lock_irq(&dev->rbsl);
462 while (dev->ring_head == dev->ring_tail) {
463 dev->interrupt_in_done = 0;
464 spin_unlock_irq(&dev->rbsl);
465 if (file->f_flags & O_NONBLOCK) {
466 retval = -EAGAIN;
467 goto unlock_exit;
468 }
469 retval = wait_event_interruptible(dev->read_wait, dev->interrupt_in_done);
470 if (retval < 0)
471 goto unlock_exit;
472
473 spin_lock_irq(&dev->rbsl);
474 }
475 spin_unlock_irq(&dev->rbsl);
476
477 /* actual_buffer contains actual_length + interrupt_in_buffer */
478 actual_buffer = (size_t *)(dev->ring_buffer + dev->ring_tail * (sizeof(size_t)+dev->interrupt_in_endpoint_size));
479 if (*actual_buffer > dev->interrupt_in_endpoint_size) {
480 retval = -EIO;
481 goto unlock_exit;
482 }
483 bytes_to_read = min(count, *actual_buffer);
484 if (bytes_to_read < *actual_buffer)
485 dev_warn(&dev->intf->dev, "Read buffer overflow, %zu bytes dropped\n",
486 *actual_buffer-bytes_to_read);
487
488 /* copy one interrupt_in_buffer from ring_buffer into userspace */
489 if (copy_to_user(buffer, actual_buffer+1, bytes_to_read)) {
490 retval = -EFAULT;
491 goto unlock_exit;
492 }
493 retval = bytes_to_read;
494
495 spin_lock_irq(&dev->rbsl);
496 dev->ring_tail = (dev->ring_tail + 1) % ring_buffer_size;
497
498 if (dev->buffer_overflow) {
499 dev->buffer_overflow = 0;
500 spin_unlock_irq(&dev->rbsl);
501 rv = usb_submit_urb(dev->interrupt_in_urb, GFP_KERNEL);
502 if (rv < 0)
503 dev->buffer_overflow = 1;
504 } else {
505 spin_unlock_irq(&dev->rbsl);
506 }
507
508unlock_exit:
509 /* unlock the device */
510 mutex_unlock(&dev->mutex);
511
512exit:
513 return retval;
514}
515
516/*
517 * ld_usb_write
518 */
519static ssize_t ld_usb_write(struct file *file, const char __user *buffer,
520 size_t count, loff_t *ppos)
521{
522 struct ld_usb *dev;
523 size_t bytes_to_write;
524 int retval = 0;
525
526 dev = file->private_data;
527
528 /* verify that we actually have some data to write */
529 if (count == 0)
530 goto exit;
531
532 /* lock this object */
533 if (mutex_lock_interruptible(&dev->mutex)) {
534 retval = -ERESTARTSYS;
535 goto exit;
536 }
537
538 /* verify that the device wasn't unplugged */
539 if (dev->disconnected) {
540 retval = -ENODEV;
541 printk(KERN_ERR "ldusb: No device or device unplugged %d\n", retval);
542 goto unlock_exit;
543 }
544
545 /* wait until previous transfer is finished */
546 if (dev->interrupt_out_busy) {
547 if (file->f_flags & O_NONBLOCK) {
548 retval = -EAGAIN;
549 goto unlock_exit;
550 }
551 retval = wait_event_interruptible(dev->write_wait, !dev->interrupt_out_busy);
552 if (retval < 0) {
553 goto unlock_exit;
554 }
555 }
556
557 /* write the data into interrupt_out_buffer from userspace */
558 bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size);
559 if (bytes_to_write < count)
560 dev_warn(&dev->intf->dev, "Write buffer overflow, %zu bytes dropped\n",
561 count - bytes_to_write);
562 dev_dbg(&dev->intf->dev, "%s: count = %zu, bytes_to_write = %zu\n",
563 __func__, count, bytes_to_write);
564
565 if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {
566 retval = -EFAULT;
567 goto unlock_exit;
568 }
569
570 if (dev->interrupt_out_endpoint == NULL) {
571 /* try HID_REQ_SET_REPORT=9 on control_endpoint instead of interrupt_out_endpoint */
572 retval = usb_control_msg(interface_to_usbdev(dev->intf),
573 usb_sndctrlpipe(interface_to_usbdev(dev->intf), 0),
574 9,
575 USB_TYPE_CLASS | USB_RECIP_INTERFACE | USB_DIR_OUT,
576 1 << 8, 0,
577 dev->interrupt_out_buffer,
578 bytes_to_write,
579 USB_CTRL_SET_TIMEOUT);
580 if (retval < 0)
581 dev_err(&dev->intf->dev,
582 "Couldn't submit HID_REQ_SET_REPORT %d\n",
583 retval);
584 goto unlock_exit;
585 }
586
587 /* send off the urb */
588 usb_fill_int_urb(dev->interrupt_out_urb,
589 interface_to_usbdev(dev->intf),
590 usb_sndintpipe(interface_to_usbdev(dev->intf),
591 dev->interrupt_out_endpoint->bEndpointAddress),
592 dev->interrupt_out_buffer,
593 bytes_to_write,
594 ld_usb_interrupt_out_callback,
595 dev,
596 dev->interrupt_out_interval);
597
598 dev->interrupt_out_busy = 1;
599 wmb();
600
601 retval = usb_submit_urb(dev->interrupt_out_urb, GFP_KERNEL);
602 if (retval) {
603 dev->interrupt_out_busy = 0;
604 dev_err(&dev->intf->dev,
605 "Couldn't submit interrupt_out_urb %d\n", retval);
606 goto unlock_exit;
607 }
608 retval = bytes_to_write;
609
610unlock_exit:
611 /* unlock the device */
612 mutex_unlock(&dev->mutex);
613
614exit:
615 return retval;
616}
617
618/* file operations needed when we register this driver */
619static const struct file_operations ld_usb_fops = {
620 .owner = THIS_MODULE,
621 .read = ld_usb_read,
622 .write = ld_usb_write,
623 .open = ld_usb_open,
624 .release = ld_usb_release,
625 .poll = ld_usb_poll,
626};
627
628/*
629 * usb class driver info in order to get a minor number from the usb core,
630 * and to have the device registered with the driver core
631 */
632static struct usb_class_driver ld_usb_class = {
633 .name = "ldusb%d",
634 .fops = &ld_usb_fops,
635 .minor_base = USB_LD_MINOR_BASE,
636};
637
638/*
639 * ld_usb_probe
640 *
641 * Called by the usb core when a new device is connected that it thinks
642 * this driver might be interested in.
643 */
644static int ld_usb_probe(struct usb_interface *intf, const struct usb_device_id *id)
645{
646 struct usb_device *udev = interface_to_usbdev(intf);
647 struct ld_usb *dev = NULL;
648 struct usb_host_interface *iface_desc;
649 char *buffer;
650 int retval = -ENOMEM;
651 int res;
652
653 /* allocate memory for our device state and initialize it */
654
655 dev = kzalloc_obj(*dev);
656 if (!dev)
657 goto exit;
658
659 kref_init(&dev->kref);
660 mutex_init(&dev->mutex);
661 spin_lock_init(&dev->rbsl);
662 dev->intf = intf;
663 init_waitqueue_head(&dev->read_wait);
664 init_waitqueue_head(&dev->write_wait);
665
666 /* workaround for early firmware versions on fast computers */
667 if ((le16_to_cpu(udev->descriptor.idVendor) == USB_VENDOR_ID_LD) &&
668 ((le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_CASSY) ||
669 (le16_to_cpu(udev->descriptor.idProduct) == USB_DEVICE_ID_LD_COM3LAB)) &&
670 (le16_to_cpu(udev->descriptor.bcdDevice) <= 0x103)) {
671 buffer = kmalloc(256, GFP_KERNEL);
672 if (!buffer)
673 goto error;
674 /* usb_string makes SETUP+STALL to leave always ControlReadLoop */
675 usb_string(udev, 255, buffer, 256);
676 kfree(buffer);
677 }
678
679 iface_desc = intf->cur_altsetting;
680
681 res = usb_find_last_int_in_endpoint(iface_desc,
682 &dev->interrupt_in_endpoint);
683 if (res) {
684 dev_err(&intf->dev, "Interrupt in endpoint not found\n");
685 retval = res;
686 goto error;
687 }
688
689 res = usb_find_last_int_out_endpoint(iface_desc,
690 &dev->interrupt_out_endpoint);
691 if (res)
692 dev_warn(&intf->dev, "Interrupt out endpoint not found (using control endpoint instead)\n");
693
694 dev->interrupt_in_endpoint_size = usb_endpoint_maxp(dev->interrupt_in_endpoint);
695 dev->ring_buffer = kcalloc(ring_buffer_size,
696 sizeof(size_t) + dev->interrupt_in_endpoint_size,
697 GFP_KERNEL);
698 if (!dev->ring_buffer)
699 goto error;
700 dev->interrupt_in_buffer = kmalloc(dev->interrupt_in_endpoint_size, GFP_KERNEL);
701 if (!dev->interrupt_in_buffer)
702 goto error;
703 dev->interrupt_in_urb = usb_alloc_urb(0, GFP_KERNEL);
704 if (!dev->interrupt_in_urb)
705 goto error;
706 dev->interrupt_out_endpoint_size = dev->interrupt_out_endpoint ? usb_endpoint_maxp(dev->interrupt_out_endpoint) :
707 udev->descriptor.bMaxPacketSize0;
708 dev->interrupt_out_buffer =
709 kmalloc_array(write_buffer_size,
710 dev->interrupt_out_endpoint_size, GFP_KERNEL);
711 if (!dev->interrupt_out_buffer)
712 goto error;
713 dev->interrupt_out_urb = usb_alloc_urb(0, GFP_KERNEL);
714 if (!dev->interrupt_out_urb)
715 goto error;
716 dev->interrupt_in_interval = max_t(int, min_interrupt_in_interval,
717 dev->interrupt_in_endpoint->bInterval);
718 if (dev->interrupt_out_endpoint)
719 dev->interrupt_out_interval = max_t(int, min_interrupt_out_interval,
720 dev->interrupt_out_endpoint->bInterval);
721
722 /* we can register the device now, as it is ready */
723 usb_set_intfdata(intf, dev);
724
725 retval = usb_register_dev(intf, &ld_usb_class);
726 if (retval) {
727 /* something prevented us from registering this driver */
728 dev_err(&intf->dev, "Not able to get a minor for this device.\n");
729 usb_set_intfdata(intf, NULL);
730 goto error;
731 }
732
733 /* let the user know what node this device is now attached to */
734 dev_info(&intf->dev, "LD USB Device #%d now attached to major %d minor %d\n",
735 (intf->minor - USB_LD_MINOR_BASE), USB_MAJOR, intf->minor);
736
737exit:
738 return retval;
739
740error:
741 kref_put(&dev->kref, ld_usb_delete);
742
743 return retval;
744}
745
746/*
747 * ld_usb_disconnect
748 *
749 * Called by the usb core when the device is removed from the system.
750 */
751static void ld_usb_disconnect(struct usb_interface *intf)
752{
753 struct ld_usb *dev;
754 int minor;
755
756 dev = usb_get_intfdata(intf);
757 usb_set_intfdata(intf, NULL);
758
759 minor = intf->minor;
760
761 /* give back our minor */
762 usb_deregister_dev(intf, &ld_usb_class);
763
764 usb_poison_urb(dev->interrupt_in_urb);
765 usb_poison_urb(dev->interrupt_out_urb);
766
767 mutex_lock(&dev->mutex);
768
769 dev->disconnected = 1;
770
771 if (dev->open_count) {
772 /* wake up pollers */
773 wake_up_interruptible_all(&dev->read_wait);
774 wake_up_interruptible_all(&dev->write_wait);
775 }
776
777 mutex_unlock(&dev->mutex);
778
779 kref_put(&dev->kref, ld_usb_delete);
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 */
786static 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
793module_usb_driver(ld_usb_driver);
794