1 /**
2 * drivers/usb/class/usbtmc.c - USB Test & Measurement class driver
3 *
4 * Copyright (C) 2007 Stefan Kopp, Gechingen, Germany
5 * Copyright (C) 2008 Novell, Inc.
6 * Copyright (C) 2008 Greg Kroah-Hartman <gregkh@suse.de>
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version 2
11 * of the License, or (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * The GNU General Public License is available at
19 * http://www.gnu.org/copyleft/gpl.html.
20 */
21
22 #include <linux/init.h>
23 #include <linux/module.h>
24 #include <linux/kernel.h>
25 #include <linux/fs.h>
26 #include <linux/uaccess.h>
27 #include <linux/kref.h>
28 #include <linux/slab.h>
29 #include <linux/mutex.h>
30 #include <linux/usb.h>
31 #include <linux/usb/tmc.h>
32
33
34 #define USBTMC_MINOR_BASE 176
35
36 /*
37 * Size of driver internal IO buffer. Must be multiple of 4 and at least as
38 * large as wMaxPacketSize (which is usually 512 bytes).
39 */
40 #define USBTMC_SIZE_IOBUFFER 2048
41
42 /* Default USB timeout (in milliseconds) */
43 #define USBTMC_TIMEOUT 5000
44
45 /*
46 * Maximum number of read cycles to empty bulk in endpoint during CLEAR and
47 * ABORT_BULK_IN requests. Ends the loop if (for whatever reason) a short
48 * packet is never read.
49 */
50 #define USBTMC_MAX_READS_TO_CLEAR_BULK_IN 100
51
52 static const struct usb_device_id usbtmc_devices[] = {
53 { USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 0), },
54 { USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 1), },
55 { 0, } /* terminating entry */
56 };
57 MODULE_DEVICE_TABLE(usb, usbtmc_devices);
58
59 /*
60 * This structure is the capabilities for the device
61 * See section 4.2.1.8 of the USBTMC specification,
62 * and section 4.2.2 of the USBTMC usb488 subclass
63 * specification for details.
64 */
65 struct usbtmc_dev_capabilities {
66 __u8 interface_capabilities;
67 __u8 device_capabilities;
68 __u8 usb488_interface_capabilities;
69 __u8 usb488_device_capabilities;
70 };
71
72 /* This structure holds private data for each USBTMC device. One copy is
73 * allocated for each USBTMC device in the driver's probe function.
74 */
75 struct usbtmc_device_data {
76 const struct usb_device_id *id;
77 struct usb_device *usb_dev;
78 struct usb_interface *intf;
79
80 unsigned int bulk_in;
81 unsigned int bulk_out;
82
83 u8 bTag;
84 u8 bTag_last_write; /* needed for abort */
85 u8 bTag_last_read; /* needed for abort */
86
87 /* attributes from the USB TMC spec for this device */
88 u8 TermChar;
89 bool TermCharEnabled;
90 bool auto_abort;
91
92 bool zombie; /* fd of disconnected device */
93
94 struct usbtmc_dev_capabilities capabilities;
95 struct kref kref;
96 struct mutex io_mutex; /* only one i/o function running at a time */
97 };
98 #define to_usbtmc_data(d) container_of(d, struct usbtmc_device_data, kref)
99
100 /* Forward declarations */
101 static struct usb_driver usbtmc_driver;
102
usbtmc_delete(struct kref * kref)103 static void usbtmc_delete(struct kref *kref)
104 {
105 struct usbtmc_device_data *data = to_usbtmc_data(kref);
106
107 usb_put_dev(data->usb_dev);
108 kfree(data);
109 }
110
usbtmc_open(struct inode * inode,struct file * filp)111 static int usbtmc_open(struct inode *inode, struct file *filp)
112 {
113 struct usb_interface *intf;
114 struct usbtmc_device_data *data;
115 int retval = 0;
116
117 intf = usb_find_interface(&usbtmc_driver, iminor(inode));
118 if (!intf) {
119 printk(KERN_ERR KBUILD_MODNAME
120 ": can not find device for minor %d", iminor(inode));
121 retval = -ENODEV;
122 goto exit;
123 }
124
125 data = usb_get_intfdata(intf);
126 kref_get(&data->kref);
127
128 /* Store pointer in file structure's private data field */
129 filp->private_data = data;
130
131 exit:
132 return retval;
133 }
134
usbtmc_release(struct inode * inode,struct file * file)135 static int usbtmc_release(struct inode *inode, struct file *file)
136 {
137 struct usbtmc_device_data *data = file->private_data;
138
139 kref_put(&data->kref, usbtmc_delete);
140 return 0;
141 }
142
usbtmc_ioctl_abort_bulk_in(struct usbtmc_device_data * data)143 static int usbtmc_ioctl_abort_bulk_in(struct usbtmc_device_data *data)
144 {
145 u8 *buffer;
146 struct device *dev;
147 int rv;
148 int n;
149 int actual;
150 struct usb_host_interface *current_setting;
151 int max_size;
152
153 dev = &data->intf->dev;
154 buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
155 if (!buffer)
156 return -ENOMEM;
157
158 rv = usb_control_msg(data->usb_dev,
159 usb_rcvctrlpipe(data->usb_dev, 0),
160 USBTMC_REQUEST_INITIATE_ABORT_BULK_IN,
161 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
162 data->bTag_last_read, data->bulk_in,
163 buffer, 2, USBTMC_TIMEOUT);
164
165 if (rv < 0) {
166 dev_err(dev, "usb_control_msg returned %d\n", rv);
167 goto exit;
168 }
169
170 dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
171
172 if (buffer[0] == USBTMC_STATUS_FAILED) {
173 rv = 0;
174 goto exit;
175 }
176
177 if (buffer[0] != USBTMC_STATUS_SUCCESS) {
178 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n",
179 buffer[0]);
180 rv = -EPERM;
181 goto exit;
182 }
183
184 max_size = 0;
185 current_setting = data->intf->cur_altsetting;
186 for (n = 0; n < current_setting->desc.bNumEndpoints; n++)
187 if (current_setting->endpoint[n].desc.bEndpointAddress ==
188 data->bulk_in)
189 max_size = usb_endpoint_maxp(¤t_setting->endpoint[n].desc);
190
191 if (max_size == 0) {
192 dev_err(dev, "Couldn't get wMaxPacketSize\n");
193 rv = -EPERM;
194 goto exit;
195 }
196
197 dev_dbg(&data->intf->dev, "wMaxPacketSize is %d\n", max_size);
198
199 n = 0;
200
201 do {
202 dev_dbg(dev, "Reading from bulk in EP\n");
203
204 rv = usb_bulk_msg(data->usb_dev,
205 usb_rcvbulkpipe(data->usb_dev,
206 data->bulk_in),
207 buffer, USBTMC_SIZE_IOBUFFER,
208 &actual, USBTMC_TIMEOUT);
209
210 n++;
211
212 if (rv < 0) {
213 dev_err(dev, "usb_bulk_msg returned %d\n", rv);
214 goto exit;
215 }
216 } while ((actual == max_size) &&
217 (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
218
219 if (actual == max_size) {
220 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
221 USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
222 rv = -EPERM;
223 goto exit;
224 }
225
226 n = 0;
227
228 usbtmc_abort_bulk_in_status:
229 rv = usb_control_msg(data->usb_dev,
230 usb_rcvctrlpipe(data->usb_dev, 0),
231 USBTMC_REQUEST_CHECK_ABORT_BULK_IN_STATUS,
232 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
233 0, data->bulk_in, buffer, 0x08,
234 USBTMC_TIMEOUT);
235
236 if (rv < 0) {
237 dev_err(dev, "usb_control_msg returned %d\n", rv);
238 goto exit;
239 }
240
241 dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
242
243 if (buffer[0] == USBTMC_STATUS_SUCCESS) {
244 rv = 0;
245 goto exit;
246 }
247
248 if (buffer[0] != USBTMC_STATUS_PENDING) {
249 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
250 rv = -EPERM;
251 goto exit;
252 }
253
254 if (buffer[1] == 1)
255 do {
256 dev_dbg(dev, "Reading from bulk in EP\n");
257
258 rv = usb_bulk_msg(data->usb_dev,
259 usb_rcvbulkpipe(data->usb_dev,
260 data->bulk_in),
261 buffer, USBTMC_SIZE_IOBUFFER,
262 &actual, USBTMC_TIMEOUT);
263
264 n++;
265
266 if (rv < 0) {
267 dev_err(dev, "usb_bulk_msg returned %d\n", rv);
268 goto exit;
269 }
270 } while ((actual == max_size) &&
271 (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
272
273 if (actual == max_size) {
274 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
275 USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
276 rv = -EPERM;
277 goto exit;
278 }
279
280 goto usbtmc_abort_bulk_in_status;
281
282 exit:
283 kfree(buffer);
284 return rv;
285
286 }
287
usbtmc_ioctl_abort_bulk_out(struct usbtmc_device_data * data)288 static int usbtmc_ioctl_abort_bulk_out(struct usbtmc_device_data *data)
289 {
290 struct device *dev;
291 u8 *buffer;
292 int rv;
293 int n;
294
295 dev = &data->intf->dev;
296
297 buffer = kmalloc(8, GFP_KERNEL);
298 if (!buffer)
299 return -ENOMEM;
300
301 rv = usb_control_msg(data->usb_dev,
302 usb_rcvctrlpipe(data->usb_dev, 0),
303 USBTMC_REQUEST_INITIATE_ABORT_BULK_OUT,
304 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
305 data->bTag_last_write, data->bulk_out,
306 buffer, 2, USBTMC_TIMEOUT);
307
308 if (rv < 0) {
309 dev_err(dev, "usb_control_msg returned %d\n", rv);
310 goto exit;
311 }
312
313 dev_dbg(dev, "INITIATE_ABORT_BULK_OUT returned %x\n", buffer[0]);
314
315 if (buffer[0] != USBTMC_STATUS_SUCCESS) {
316 dev_err(dev, "INITIATE_ABORT_BULK_OUT returned %x\n",
317 buffer[0]);
318 rv = -EPERM;
319 goto exit;
320 }
321
322 n = 0;
323
324 usbtmc_abort_bulk_out_check_status:
325 rv = usb_control_msg(data->usb_dev,
326 usb_rcvctrlpipe(data->usb_dev, 0),
327 USBTMC_REQUEST_CHECK_ABORT_BULK_OUT_STATUS,
328 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
329 0, data->bulk_out, buffer, 0x08,
330 USBTMC_TIMEOUT);
331 n++;
332 if (rv < 0) {
333 dev_err(dev, "usb_control_msg returned %d\n", rv);
334 goto exit;
335 }
336
337 dev_dbg(dev, "CHECK_ABORT_BULK_OUT returned %x\n", buffer[0]);
338
339 if (buffer[0] == USBTMC_STATUS_SUCCESS)
340 goto usbtmc_abort_bulk_out_clear_halt;
341
342 if ((buffer[0] == USBTMC_STATUS_PENDING) &&
343 (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN))
344 goto usbtmc_abort_bulk_out_check_status;
345
346 rv = -EPERM;
347 goto exit;
348
349 usbtmc_abort_bulk_out_clear_halt:
350 rv = usb_clear_halt(data->usb_dev,
351 usb_sndbulkpipe(data->usb_dev, data->bulk_out));
352
353 if (rv < 0) {
354 dev_err(dev, "usb_control_msg returned %d\n", rv);
355 goto exit;
356 }
357 rv = 0;
358
359 exit:
360 kfree(buffer);
361 return rv;
362 }
363
usbtmc_read(struct file * filp,char __user * buf,size_t count,loff_t * f_pos)364 static ssize_t usbtmc_read(struct file *filp, char __user *buf,
365 size_t count, loff_t *f_pos)
366 {
367 struct usbtmc_device_data *data;
368 struct device *dev;
369 u32 n_characters;
370 u8 *buffer;
371 int actual;
372 size_t done;
373 size_t remaining;
374 int retval;
375 size_t this_part;
376
377 /* Get pointer to private data structure */
378 data = filp->private_data;
379 dev = &data->intf->dev;
380
381 buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
382 if (!buffer)
383 return -ENOMEM;
384
385 mutex_lock(&data->io_mutex);
386 if (data->zombie) {
387 retval = -ENODEV;
388 goto exit;
389 }
390
391 remaining = count;
392 done = 0;
393
394 while (remaining > 0) {
395 if (remaining > USBTMC_SIZE_IOBUFFER - 12 - 3)
396 this_part = USBTMC_SIZE_IOBUFFER - 12 - 3;
397 else
398 this_part = remaining;
399
400 /* Setup IO buffer for DEV_DEP_MSG_IN message
401 * Refer to class specs for details
402 */
403 buffer[0] = 2;
404 buffer[1] = data->bTag;
405 buffer[2] = ~(data->bTag);
406 buffer[3] = 0; /* Reserved */
407 buffer[4] = (this_part) & 255;
408 buffer[5] = ((this_part) >> 8) & 255;
409 buffer[6] = ((this_part) >> 16) & 255;
410 buffer[7] = ((this_part) >> 24) & 255;
411 buffer[8] = data->TermCharEnabled * 2;
412 /* Use term character? */
413 buffer[9] = data->TermChar;
414 buffer[10] = 0; /* Reserved */
415 buffer[11] = 0; /* Reserved */
416
417 /* Send bulk URB */
418 retval = usb_bulk_msg(data->usb_dev,
419 usb_sndbulkpipe(data->usb_dev,
420 data->bulk_out),
421 buffer, 12, &actual, USBTMC_TIMEOUT);
422
423 /* Store bTag (in case we need to abort) */
424 data->bTag_last_write = data->bTag;
425
426 /* Increment bTag -- and increment again if zero */
427 data->bTag++;
428 if (!data->bTag)
429 (data->bTag)++;
430
431 if (retval < 0) {
432 dev_err(dev, "usb_bulk_msg returned %d\n", retval);
433 if (data->auto_abort)
434 usbtmc_ioctl_abort_bulk_out(data);
435 goto exit;
436 }
437
438 /* Send bulk URB */
439 retval = usb_bulk_msg(data->usb_dev,
440 usb_rcvbulkpipe(data->usb_dev,
441 data->bulk_in),
442 buffer, USBTMC_SIZE_IOBUFFER, &actual,
443 USBTMC_TIMEOUT);
444
445 /* Store bTag (in case we need to abort) */
446 data->bTag_last_read = data->bTag;
447
448 if (retval < 0) {
449 dev_err(dev, "Unable to read data, error %d\n", retval);
450 if (data->auto_abort)
451 usbtmc_ioctl_abort_bulk_in(data);
452 goto exit;
453 }
454
455 /* How many characters did the instrument send? */
456 n_characters = buffer[4] +
457 (buffer[5] << 8) +
458 (buffer[6] << 16) +
459 (buffer[7] << 24);
460
461 /* Ensure the instrument doesn't lie about it */
462 if(n_characters > actual - 12) {
463 dev_err(dev, "Device lies about message size: %u > %d\n", n_characters, actual - 12);
464 n_characters = actual - 12;
465 }
466
467 /* Ensure the instrument doesn't send more back than requested */
468 if(n_characters > this_part) {
469 dev_err(dev, "Device returns more than requested: %zu > %zu\n", done + n_characters, done + this_part);
470 n_characters = this_part;
471 }
472
473 /* Bound amount of data received by amount of data requested */
474 if (n_characters > this_part)
475 n_characters = this_part;
476
477 /* Copy buffer to user space */
478 if (copy_to_user(buf + done, &buffer[12], n_characters)) {
479 /* There must have been an addressing problem */
480 retval = -EFAULT;
481 goto exit;
482 }
483
484 done += n_characters;
485 /* Terminate if end-of-message bit received from device */
486 if ((buffer[8] & 0x01) && (actual >= n_characters + 12))
487 remaining = 0;
488 else
489 remaining -= n_characters;
490 }
491
492 /* Update file position value */
493 *f_pos = *f_pos + done;
494 retval = done;
495
496 exit:
497 mutex_unlock(&data->io_mutex);
498 kfree(buffer);
499 return retval;
500 }
501
usbtmc_write(struct file * filp,const char __user * buf,size_t count,loff_t * f_pos)502 static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
503 size_t count, loff_t *f_pos)
504 {
505 struct usbtmc_device_data *data;
506 u8 *buffer;
507 int retval;
508 int actual;
509 unsigned long int n_bytes;
510 int remaining;
511 int done;
512 int this_part;
513
514 data = filp->private_data;
515
516 buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
517 if (!buffer)
518 return -ENOMEM;
519
520 mutex_lock(&data->io_mutex);
521 if (data->zombie) {
522 retval = -ENODEV;
523 goto exit;
524 }
525
526 remaining = count;
527 done = 0;
528
529 while (remaining > 0) {
530 if (remaining > USBTMC_SIZE_IOBUFFER - 12) {
531 this_part = USBTMC_SIZE_IOBUFFER - 12;
532 buffer[8] = 0;
533 } else {
534 this_part = remaining;
535 buffer[8] = 1;
536 }
537
538 /* Setup IO buffer for DEV_DEP_MSG_OUT message */
539 buffer[0] = 1;
540 buffer[1] = data->bTag;
541 buffer[2] = ~(data->bTag);
542 buffer[3] = 0; /* Reserved */
543 buffer[4] = this_part & 255;
544 buffer[5] = (this_part >> 8) & 255;
545 buffer[6] = (this_part >> 16) & 255;
546 buffer[7] = (this_part >> 24) & 255;
547 /* buffer[8] is set above... */
548 buffer[9] = 0; /* Reserved */
549 buffer[10] = 0; /* Reserved */
550 buffer[11] = 0; /* Reserved */
551
552 if (copy_from_user(&buffer[12], buf + done, this_part)) {
553 retval = -EFAULT;
554 goto exit;
555 }
556
557 n_bytes = roundup(12 + this_part, 4);
558 memset(buffer + 12 + this_part, 0, n_bytes - (12 + this_part));
559
560 do {
561 retval = usb_bulk_msg(data->usb_dev,
562 usb_sndbulkpipe(data->usb_dev,
563 data->bulk_out),
564 buffer, n_bytes,
565 &actual, USBTMC_TIMEOUT);
566 if (retval != 0)
567 break;
568 n_bytes -= actual;
569 } while (n_bytes);
570
571 data->bTag_last_write = data->bTag;
572 data->bTag++;
573
574 if (!data->bTag)
575 data->bTag++;
576
577 if (retval < 0) {
578 dev_err(&data->intf->dev,
579 "Unable to send data, error %d\n", retval);
580 if (data->auto_abort)
581 usbtmc_ioctl_abort_bulk_out(data);
582 goto exit;
583 }
584
585 remaining -= this_part;
586 done += this_part;
587 }
588
589 retval = count;
590 exit:
591 mutex_unlock(&data->io_mutex);
592 kfree(buffer);
593 return retval;
594 }
595
usbtmc_ioctl_clear(struct usbtmc_device_data * data)596 static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
597 {
598 struct usb_host_interface *current_setting;
599 struct usb_endpoint_descriptor *desc;
600 struct device *dev;
601 u8 *buffer;
602 int rv;
603 int n;
604 int actual;
605 int max_size;
606
607 dev = &data->intf->dev;
608
609 dev_dbg(dev, "Sending INITIATE_CLEAR request\n");
610
611 buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
612 if (!buffer)
613 return -ENOMEM;
614
615 rv = usb_control_msg(data->usb_dev,
616 usb_rcvctrlpipe(data->usb_dev, 0),
617 USBTMC_REQUEST_INITIATE_CLEAR,
618 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
619 0, 0, buffer, 1, USBTMC_TIMEOUT);
620 if (rv < 0) {
621 dev_err(dev, "usb_control_msg returned %d\n", rv);
622 goto exit;
623 }
624
625 dev_dbg(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
626
627 if (buffer[0] != USBTMC_STATUS_SUCCESS) {
628 dev_err(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
629 rv = -EPERM;
630 goto exit;
631 }
632
633 max_size = 0;
634 current_setting = data->intf->cur_altsetting;
635 for (n = 0; n < current_setting->desc.bNumEndpoints; n++) {
636 desc = ¤t_setting->endpoint[n].desc;
637 if (desc->bEndpointAddress == data->bulk_in)
638 max_size = usb_endpoint_maxp(desc);
639 }
640
641 if (max_size == 0) {
642 dev_err(dev, "Couldn't get wMaxPacketSize\n");
643 rv = -EPERM;
644 goto exit;
645 }
646
647 dev_dbg(dev, "wMaxPacketSize is %d\n", max_size);
648
649 n = 0;
650
651 usbtmc_clear_check_status:
652
653 dev_dbg(dev, "Sending CHECK_CLEAR_STATUS request\n");
654
655 rv = usb_control_msg(data->usb_dev,
656 usb_rcvctrlpipe(data->usb_dev, 0),
657 USBTMC_REQUEST_CHECK_CLEAR_STATUS,
658 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
659 0, 0, buffer, 2, USBTMC_TIMEOUT);
660 if (rv < 0) {
661 dev_err(dev, "usb_control_msg returned %d\n", rv);
662 goto exit;
663 }
664
665 dev_dbg(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
666
667 if (buffer[0] == USBTMC_STATUS_SUCCESS)
668 goto usbtmc_clear_bulk_out_halt;
669
670 if (buffer[0] != USBTMC_STATUS_PENDING) {
671 dev_err(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
672 rv = -EPERM;
673 goto exit;
674 }
675
676 if (buffer[1] == 1)
677 do {
678 dev_dbg(dev, "Reading from bulk in EP\n");
679
680 rv = usb_bulk_msg(data->usb_dev,
681 usb_rcvbulkpipe(data->usb_dev,
682 data->bulk_in),
683 buffer, USBTMC_SIZE_IOBUFFER,
684 &actual, USBTMC_TIMEOUT);
685 n++;
686
687 if (rv < 0) {
688 dev_err(dev, "usb_control_msg returned %d\n",
689 rv);
690 goto exit;
691 }
692 } while ((actual == max_size) &&
693 (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
694
695 if (actual == max_size) {
696 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
697 USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
698 rv = -EPERM;
699 goto exit;
700 }
701
702 goto usbtmc_clear_check_status;
703
704 usbtmc_clear_bulk_out_halt:
705
706 rv = usb_clear_halt(data->usb_dev,
707 usb_sndbulkpipe(data->usb_dev, data->bulk_out));
708 if (rv < 0) {
709 dev_err(dev, "usb_control_msg returned %d\n", rv);
710 goto exit;
711 }
712 rv = 0;
713
714 exit:
715 kfree(buffer);
716 return rv;
717 }
718
usbtmc_ioctl_clear_out_halt(struct usbtmc_device_data * data)719 static int usbtmc_ioctl_clear_out_halt(struct usbtmc_device_data *data)
720 {
721 u8 *buffer;
722 int rv;
723
724 buffer = kmalloc(2, GFP_KERNEL);
725 if (!buffer)
726 return -ENOMEM;
727
728 rv = usb_clear_halt(data->usb_dev,
729 usb_sndbulkpipe(data->usb_dev, data->bulk_out));
730
731 if (rv < 0) {
732 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
733 rv);
734 goto exit;
735 }
736 rv = 0;
737
738 exit:
739 kfree(buffer);
740 return rv;
741 }
742
usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data * data)743 static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data)
744 {
745 u8 *buffer;
746 int rv;
747
748 buffer = kmalloc(2, GFP_KERNEL);
749 if (!buffer)
750 return -ENOMEM;
751
752 rv = usb_clear_halt(data->usb_dev,
753 usb_rcvbulkpipe(data->usb_dev, data->bulk_in));
754
755 if (rv < 0) {
756 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
757 rv);
758 goto exit;
759 }
760 rv = 0;
761
762 exit:
763 kfree(buffer);
764 return rv;
765 }
766
get_capabilities(struct usbtmc_device_data * data)767 static int get_capabilities(struct usbtmc_device_data *data)
768 {
769 struct device *dev = &data->usb_dev->dev;
770 char *buffer;
771 int rv = 0;
772
773 buffer = kmalloc(0x18, GFP_KERNEL);
774 if (!buffer)
775 return -ENOMEM;
776
777 rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0),
778 USBTMC_REQUEST_GET_CAPABILITIES,
779 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
780 0, 0, buffer, 0x18, USBTMC_TIMEOUT);
781 if (rv < 0) {
782 dev_err(dev, "usb_control_msg returned %d\n", rv);
783 goto err_out;
784 }
785
786 dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
787 if (buffer[0] != USBTMC_STATUS_SUCCESS) {
788 dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
789 rv = -EPERM;
790 goto err_out;
791 }
792 dev_dbg(dev, "Interface capabilities are %x\n", buffer[4]);
793 dev_dbg(dev, "Device capabilities are %x\n", buffer[5]);
794 dev_dbg(dev, "USB488 interface capabilities are %x\n", buffer[14]);
795 dev_dbg(dev, "USB488 device capabilities are %x\n", buffer[15]);
796
797 data->capabilities.interface_capabilities = buffer[4];
798 data->capabilities.device_capabilities = buffer[5];
799 data->capabilities.usb488_interface_capabilities = buffer[14];
800 data->capabilities.usb488_device_capabilities = buffer[15];
801 rv = 0;
802
803 err_out:
804 kfree(buffer);
805 return rv;
806 }
807
808 #define capability_attribute(name) \
809 static ssize_t show_##name(struct device *dev, \
810 struct device_attribute *attr, char *buf) \
811 { \
812 struct usb_interface *intf = to_usb_interface(dev); \
813 struct usbtmc_device_data *data = usb_get_intfdata(intf); \
814 \
815 return sprintf(buf, "%d\n", data->capabilities.name); \
816 } \
817 static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
818
819 capability_attribute(interface_capabilities);
820 capability_attribute(device_capabilities);
821 capability_attribute(usb488_interface_capabilities);
822 capability_attribute(usb488_device_capabilities);
823
824 static struct attribute *capability_attrs[] = {
825 &dev_attr_interface_capabilities.attr,
826 &dev_attr_device_capabilities.attr,
827 &dev_attr_usb488_interface_capabilities.attr,
828 &dev_attr_usb488_device_capabilities.attr,
829 NULL,
830 };
831
832 static struct attribute_group capability_attr_grp = {
833 .attrs = capability_attrs,
834 };
835
show_TermChar(struct device * dev,struct device_attribute * attr,char * buf)836 static ssize_t show_TermChar(struct device *dev,
837 struct device_attribute *attr, char *buf)
838 {
839 struct usb_interface *intf = to_usb_interface(dev);
840 struct usbtmc_device_data *data = usb_get_intfdata(intf);
841
842 return sprintf(buf, "%c\n", data->TermChar);
843 }
844
store_TermChar(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)845 static ssize_t store_TermChar(struct device *dev,
846 struct device_attribute *attr,
847 const char *buf, size_t count)
848 {
849 struct usb_interface *intf = to_usb_interface(dev);
850 struct usbtmc_device_data *data = usb_get_intfdata(intf);
851
852 if (count < 1)
853 return -EINVAL;
854 data->TermChar = buf[0];
855 return count;
856 }
857 static DEVICE_ATTR(TermChar, S_IRUGO, show_TermChar, store_TermChar);
858
859 #define data_attribute(name) \
860 static ssize_t show_##name(struct device *dev, \
861 struct device_attribute *attr, char *buf) \
862 { \
863 struct usb_interface *intf = to_usb_interface(dev); \
864 struct usbtmc_device_data *data = usb_get_intfdata(intf); \
865 \
866 return sprintf(buf, "%d\n", data->name); \
867 } \
868 static ssize_t store_##name(struct device *dev, \
869 struct device_attribute *attr, \
870 const char *buf, size_t count) \
871 { \
872 struct usb_interface *intf = to_usb_interface(dev); \
873 struct usbtmc_device_data *data = usb_get_intfdata(intf); \
874 ssize_t result; \
875 unsigned val; \
876 \
877 result = sscanf(buf, "%u\n", &val); \
878 if (result != 1) \
879 result = -EINVAL; \
880 data->name = val; \
881 if (result < 0) \
882 return result; \
883 else \
884 return count; \
885 } \
886 static DEVICE_ATTR(name, S_IRUGO, show_##name, store_##name)
887
888 data_attribute(TermCharEnabled);
889 data_attribute(auto_abort);
890
891 static struct attribute *data_attrs[] = {
892 &dev_attr_TermChar.attr,
893 &dev_attr_TermCharEnabled.attr,
894 &dev_attr_auto_abort.attr,
895 NULL,
896 };
897
898 static struct attribute_group data_attr_grp = {
899 .attrs = data_attrs,
900 };
901
usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data * data)902 static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
903 {
904 struct device *dev;
905 u8 *buffer;
906 int rv;
907
908 dev = &data->intf->dev;
909
910 buffer = kmalloc(2, GFP_KERNEL);
911 if (!buffer)
912 return -ENOMEM;
913
914 rv = usb_control_msg(data->usb_dev,
915 usb_rcvctrlpipe(data->usb_dev, 0),
916 USBTMC_REQUEST_INDICATOR_PULSE,
917 USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
918 0, 0, buffer, 0x01, USBTMC_TIMEOUT);
919
920 if (rv < 0) {
921 dev_err(dev, "usb_control_msg returned %d\n", rv);
922 goto exit;
923 }
924
925 dev_dbg(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
926
927 if (buffer[0] != USBTMC_STATUS_SUCCESS) {
928 dev_err(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
929 rv = -EPERM;
930 goto exit;
931 }
932 rv = 0;
933
934 exit:
935 kfree(buffer);
936 return rv;
937 }
938
usbtmc_ioctl(struct file * file,unsigned int cmd,unsigned long arg)939 static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
940 {
941 struct usbtmc_device_data *data;
942 int retval = -EBADRQC;
943
944 data = file->private_data;
945 mutex_lock(&data->io_mutex);
946 if (data->zombie) {
947 retval = -ENODEV;
948 goto skip_io_on_zombie;
949 }
950
951 switch (cmd) {
952 case USBTMC_IOCTL_CLEAR_OUT_HALT:
953 retval = usbtmc_ioctl_clear_out_halt(data);
954 break;
955
956 case USBTMC_IOCTL_CLEAR_IN_HALT:
957 retval = usbtmc_ioctl_clear_in_halt(data);
958 break;
959
960 case USBTMC_IOCTL_INDICATOR_PULSE:
961 retval = usbtmc_ioctl_indicator_pulse(data);
962 break;
963
964 case USBTMC_IOCTL_CLEAR:
965 retval = usbtmc_ioctl_clear(data);
966 break;
967
968 case USBTMC_IOCTL_ABORT_BULK_OUT:
969 retval = usbtmc_ioctl_abort_bulk_out(data);
970 break;
971
972 case USBTMC_IOCTL_ABORT_BULK_IN:
973 retval = usbtmc_ioctl_abort_bulk_in(data);
974 break;
975 }
976
977 skip_io_on_zombie:
978 mutex_unlock(&data->io_mutex);
979 return retval;
980 }
981
982 static const struct file_operations fops = {
983 .owner = THIS_MODULE,
984 .read = usbtmc_read,
985 .write = usbtmc_write,
986 .open = usbtmc_open,
987 .release = usbtmc_release,
988 .unlocked_ioctl = usbtmc_ioctl,
989 .llseek = default_llseek,
990 };
991
992 static struct usb_class_driver usbtmc_class = {
993 .name = "usbtmc%d",
994 .fops = &fops,
995 .minor_base = USBTMC_MINOR_BASE,
996 };
997
998
usbtmc_probe(struct usb_interface * intf,const struct usb_device_id * id)999 static int usbtmc_probe(struct usb_interface *intf,
1000 const struct usb_device_id *id)
1001 {
1002 struct usbtmc_device_data *data;
1003 struct usb_host_interface *iface_desc;
1004 struct usb_endpoint_descriptor *endpoint;
1005 int n;
1006 int retcode;
1007
1008 dev_dbg(&intf->dev, "%s called\n", __func__);
1009
1010 data = kmalloc(sizeof(struct usbtmc_device_data), GFP_KERNEL);
1011 if (!data) {
1012 dev_err(&intf->dev, "Unable to allocate kernel memory\n");
1013 return -ENOMEM;
1014 }
1015
1016 data->intf = intf;
1017 data->id = id;
1018 data->usb_dev = usb_get_dev(interface_to_usbdev(intf));
1019 usb_set_intfdata(intf, data);
1020 kref_init(&data->kref);
1021 mutex_init(&data->io_mutex);
1022 data->zombie = 0;
1023
1024 /* Initialize USBTMC bTag and other fields */
1025 data->bTag = 1;
1026 data->TermCharEnabled = 0;
1027 data->TermChar = '\n';
1028
1029 /* USBTMC devices have only one setting, so use that */
1030 iface_desc = data->intf->cur_altsetting;
1031
1032 /* Find bulk in endpoint */
1033 for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1034 endpoint = &iface_desc->endpoint[n].desc;
1035
1036 if (usb_endpoint_is_bulk_in(endpoint)) {
1037 data->bulk_in = endpoint->bEndpointAddress;
1038 dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n",
1039 data->bulk_in);
1040 break;
1041 }
1042 }
1043
1044 /* Find bulk out endpoint */
1045 for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1046 endpoint = &iface_desc->endpoint[n].desc;
1047
1048 if (usb_endpoint_is_bulk_out(endpoint)) {
1049 data->bulk_out = endpoint->bEndpointAddress;
1050 dev_dbg(&intf->dev, "Found Bulk out endpoint at %u\n",
1051 data->bulk_out);
1052 break;
1053 }
1054 }
1055
1056 retcode = get_capabilities(data);
1057 if (retcode)
1058 dev_err(&intf->dev, "can't read capabilities\n");
1059 else
1060 retcode = sysfs_create_group(&intf->dev.kobj,
1061 &capability_attr_grp);
1062
1063 retcode = sysfs_create_group(&intf->dev.kobj, &data_attr_grp);
1064
1065 retcode = usb_register_dev(intf, &usbtmc_class);
1066 if (retcode) {
1067 dev_err(&intf->dev, "Not able to get a minor"
1068 " (base %u, slice default): %d\n", USBTMC_MINOR_BASE,
1069 retcode);
1070 goto error_register;
1071 }
1072 dev_dbg(&intf->dev, "Using minor number %d\n", intf->minor);
1073
1074 return 0;
1075
1076 error_register:
1077 sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1078 sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1079 kref_put(&data->kref, usbtmc_delete);
1080 return retcode;
1081 }
1082
usbtmc_disconnect(struct usb_interface * intf)1083 static void usbtmc_disconnect(struct usb_interface *intf)
1084 {
1085 struct usbtmc_device_data *data;
1086
1087 dev_dbg(&intf->dev, "usbtmc_disconnect called\n");
1088
1089 data = usb_get_intfdata(intf);
1090 usb_deregister_dev(intf, &usbtmc_class);
1091 sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1092 sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1093 mutex_lock(&data->io_mutex);
1094 data->zombie = 1;
1095 mutex_unlock(&data->io_mutex);
1096 kref_put(&data->kref, usbtmc_delete);
1097 }
1098
usbtmc_suspend(struct usb_interface * intf,pm_message_t message)1099 static int usbtmc_suspend(struct usb_interface *intf, pm_message_t message)
1100 {
1101 /* this driver does not have pending URBs */
1102 return 0;
1103 }
1104
usbtmc_resume(struct usb_interface * intf)1105 static int usbtmc_resume(struct usb_interface *intf)
1106 {
1107 return 0;
1108 }
1109
1110 static struct usb_driver usbtmc_driver = {
1111 .name = "usbtmc",
1112 .id_table = usbtmc_devices,
1113 .probe = usbtmc_probe,
1114 .disconnect = usbtmc_disconnect,
1115 .suspend = usbtmc_suspend,
1116 .resume = usbtmc_resume,
1117 };
1118
1119 module_usb_driver(usbtmc_driver);
1120
1121 MODULE_LICENSE("GPL");
1122