Merge commit 'v3.4.4' into android-tegra-nv-3.4
[linux-2.6.git] / drivers / usb / class / usbtmc.c
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
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
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
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
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(&current_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
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
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
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
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 = &current_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
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
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
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
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
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
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
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
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
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
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
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");