tree-wide: fix assorted typos all over the place
[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/mutex.h>
29 #include <linux/usb.h>
30 #include <linux/usb/tmc.h>
31
32
33 #define USBTMC_MINOR_BASE       176
34
35 /*
36  * Size of driver internal IO buffer. Must be multiple of 4 and at least as
37  * large as wMaxPacketSize (which is usually 512 bytes).
38  */
39 #define USBTMC_SIZE_IOBUFFER    2048
40
41 /* Default USB timeout (in milliseconds) */
42 #define USBTMC_TIMEOUT          5000
43
44 /*
45  * Maximum number of read cycles to empty bulk in endpoint during CLEAR and
46  * ABORT_BULK_IN requests. Ends the loop if (for whatever reason) a short
47  * packet is never read.
48  */
49 #define USBTMC_MAX_READS_TO_CLEAR_BULK_IN       100
50
51 static struct usb_device_id usbtmc_devices[] = {
52         { USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 0), },
53         { USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 1), },
54         { 0, } /* terminating entry */
55 };
56 MODULE_DEVICE_TABLE(usb, usbtmc_devices);
57
58 /*
59  * This structure is the capabilities for the device
60  * See section 4.2.1.8 of the USBTMC specification,
61  * and section 4.2.2 of the USBTMC usb488 subclass
62  * specification for details.
63  */
64 struct usbtmc_dev_capabilities {
65         __u8 interface_capabilities;
66         __u8 device_capabilities;
67         __u8 usb488_interface_capabilities;
68         __u8 usb488_device_capabilities;
69 };
70
71 /* This structure holds private data for each USBTMC device. One copy is
72  * allocated for each USBTMC device in the driver's probe function.
73  */
74 struct usbtmc_device_data {
75         const struct usb_device_id *id;
76         struct usb_device *usb_dev;
77         struct usb_interface *intf;
78
79         unsigned int bulk_in;
80         unsigned int bulk_out;
81
82         u8 bTag;
83         u8 bTag_last_write;     /* needed for abort */
84         u8 bTag_last_read;      /* needed for abort */
85
86         /* attributes from the USB TMC spec for this device */
87         u8 TermChar;
88         bool TermCharEnabled;
89         bool auto_abort;
90
91         bool zombie; /* fd of disconnected device */
92
93         struct usbtmc_dev_capabilities  capabilities;
94         struct kref kref;
95         struct mutex io_mutex;  /* only one i/o function running at a time */
96 };
97 #define to_usbtmc_data(d) container_of(d, struct usbtmc_device_data, kref)
98
99 /* Forward declarations */
100 static struct usb_driver usbtmc_driver;
101
102 static void usbtmc_delete(struct kref *kref)
103 {
104         struct usbtmc_device_data *data = to_usbtmc_data(kref);
105
106         usb_put_dev(data->usb_dev);
107         kfree(data);
108 }
109
110 static int usbtmc_open(struct inode *inode, struct file *filp)
111 {
112         struct usb_interface *intf;
113         struct usbtmc_device_data *data;
114         int retval = 0;
115
116         intf = usb_find_interface(&usbtmc_driver, iminor(inode));
117         if (!intf) {
118                 printk(KERN_ERR KBUILD_MODNAME
119                        ": can not find device for minor %d", iminor(inode));
120                 retval = -ENODEV;
121                 goto exit;
122         }
123
124         data = usb_get_intfdata(intf);
125         kref_get(&data->kref);
126
127         /* Store pointer in file structure's private data field */
128         filp->private_data = data;
129
130 exit:
131         return retval;
132 }
133
134 static int usbtmc_release(struct inode *inode, struct file *file)
135 {
136         struct usbtmc_device_data *data = file->private_data;
137
138         kref_put(&data->kref, usbtmc_delete);
139         return 0;
140 }
141
142 static int usbtmc_ioctl_abort_bulk_in(struct usbtmc_device_data *data)
143 {
144         u8 *buffer;
145         struct device *dev;
146         int rv;
147         int n;
148         int actual;
149         struct usb_host_interface *current_setting;
150         int max_size;
151
152         dev = &data->intf->dev;
153         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
154         if (!buffer)
155                 return -ENOMEM;
156
157         rv = usb_control_msg(data->usb_dev,
158                              usb_rcvctrlpipe(data->usb_dev, 0),
159                              USBTMC_REQUEST_INITIATE_ABORT_BULK_IN,
160                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
161                              data->bTag_last_read, data->bulk_in,
162                              buffer, 2, USBTMC_TIMEOUT);
163
164         if (rv < 0) {
165                 dev_err(dev, "usb_control_msg returned %d\n", rv);
166                 goto exit;
167         }
168
169         dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
170
171         if (buffer[0] == USBTMC_STATUS_FAILED) {
172                 rv = 0;
173                 goto exit;
174         }
175
176         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
177                 dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n",
178                         buffer[0]);
179                 rv = -EPERM;
180                 goto exit;
181         }
182
183         max_size = 0;
184         current_setting = data->intf->cur_altsetting;
185         for (n = 0; n < current_setting->desc.bNumEndpoints; n++)
186                 if (current_setting->endpoint[n].desc.bEndpointAddress ==
187                         data->bulk_in)
188                         max_size = le16_to_cpu(current_setting->endpoint[n].
189                                                 desc.wMaxPacketSize);
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_control_msg(data->usb_dev,
351                              usb_sndctrlpipe(data->usb_dev, 0),
352                              USB_REQ_CLEAR_FEATURE,
353                              USB_DIR_OUT | USB_TYPE_STANDARD |
354                              USB_RECIP_ENDPOINT,
355                              USB_ENDPOINT_HALT, data->bulk_out, buffer,
356                              0, USBTMC_TIMEOUT);
357
358         if (rv < 0) {
359                 dev_err(dev, "usb_control_msg returned %d\n", rv);
360                 goto exit;
361         }
362         rv = 0;
363
364 exit:
365         kfree(buffer);
366         return rv;
367 }
368
369 static ssize_t usbtmc_read(struct file *filp, char __user *buf,
370                            size_t count, loff_t *f_pos)
371 {
372         struct usbtmc_device_data *data;
373         struct device *dev;
374         u32 n_characters;
375         u8 *buffer;
376         int actual;
377         size_t done;
378         size_t remaining;
379         int retval;
380         size_t this_part;
381
382         /* Get pointer to private data structure */
383         data = filp->private_data;
384         dev = &data->intf->dev;
385
386         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
387         if (!buffer)
388                 return -ENOMEM;
389
390         mutex_lock(&data->io_mutex);
391         if (data->zombie) {
392                 retval = -ENODEV;
393                 goto exit;
394         }
395
396         remaining = count;
397         done = 0;
398
399         while (remaining > 0) {
400                 if (remaining > USBTMC_SIZE_IOBUFFER - 12 - 3)
401                         this_part = USBTMC_SIZE_IOBUFFER - 12 - 3;
402                 else
403                         this_part = remaining;
404
405                 /* Setup IO buffer for DEV_DEP_MSG_IN message
406                  * Refer to class specs for details
407                  */
408                 buffer[0] = 2;
409                 buffer[1] = data->bTag;
410                 buffer[2] = ~(data->bTag);
411                 buffer[3] = 0; /* Reserved */
412                 buffer[4] = (this_part) & 255;
413                 buffer[5] = ((this_part) >> 8) & 255;
414                 buffer[6] = ((this_part) >> 16) & 255;
415                 buffer[7] = ((this_part) >> 24) & 255;
416                 buffer[8] = data->TermCharEnabled * 2;
417                 /* Use term character? */
418                 buffer[9] = data->TermChar;
419                 buffer[10] = 0; /* Reserved */
420                 buffer[11] = 0; /* Reserved */
421
422                 /* Send bulk URB */
423                 retval = usb_bulk_msg(data->usb_dev,
424                                       usb_sndbulkpipe(data->usb_dev,
425                                                       data->bulk_out),
426                                       buffer, 12, &actual, USBTMC_TIMEOUT);
427
428                 /* Store bTag (in case we need to abort) */
429                 data->bTag_last_write = data->bTag;
430
431                 /* Increment bTag -- and increment again if zero */
432                 data->bTag++;
433                 if (!data->bTag)
434                         (data->bTag)++;
435
436                 if (retval < 0) {
437                         dev_err(dev, "usb_bulk_msg returned %d\n", retval);
438                         if (data->auto_abort)
439                                 usbtmc_ioctl_abort_bulk_out(data);
440                         goto exit;
441                 }
442
443                 /* Send bulk URB */
444                 retval = usb_bulk_msg(data->usb_dev,
445                                       usb_rcvbulkpipe(data->usb_dev,
446                                                       data->bulk_in),
447                                       buffer, USBTMC_SIZE_IOBUFFER, &actual,
448                                       USBTMC_TIMEOUT);
449
450                 /* Store bTag (in case we need to abort) */
451                 data->bTag_last_read = data->bTag;
452
453                 if (retval < 0) {
454                         dev_err(dev, "Unable to read data, error %d\n", retval);
455                         if (data->auto_abort)
456                                 usbtmc_ioctl_abort_bulk_in(data);
457                         goto exit;
458                 }
459
460                 /* How many characters did the instrument send? */
461                 n_characters = buffer[4] +
462                                (buffer[5] << 8) +
463                                (buffer[6] << 16) +
464                                (buffer[7] << 24);
465
466                 /* Ensure the instrument doesn't lie about it */
467                 if(n_characters > actual - 12) {
468                         dev_err(dev, "Device lies about message size: %u > %d\n", n_characters, actual - 12);
469                         n_characters = actual - 12;
470                 }
471
472                 /* Ensure the instrument doesn't send more back than requested */
473                 if(n_characters > this_part) {
474                         dev_err(dev, "Device returns more than requested: %zu > %zu\n", done + n_characters, done + this_part);
475                         n_characters = this_part;
476                 }
477
478                 /* Bound amount of data received by amount of data requested */
479                 if (n_characters > this_part)
480                         n_characters = this_part;
481
482                 /* Copy buffer to user space */
483                 if (copy_to_user(buf + done, &buffer[12], n_characters)) {
484                         /* There must have been an addressing problem */
485                         retval = -EFAULT;
486                         goto exit;
487                 }
488
489                 done += n_characters;
490                 /* Terminate if end-of-message bit recieved from device */
491                 if ((buffer[8] &  0x01) && (actual >= n_characters + 12))
492                         remaining = 0;
493                 else
494                         remaining -= n_characters;
495         }
496
497         /* Update file position value */
498         *f_pos = *f_pos + done;
499         retval = done;
500
501 exit:
502         mutex_unlock(&data->io_mutex);
503         kfree(buffer);
504         return retval;
505 }
506
507 static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
508                             size_t count, loff_t *f_pos)
509 {
510         struct usbtmc_device_data *data;
511         u8 *buffer;
512         int retval;
513         int actual;
514         unsigned long int n_bytes;
515         int remaining;
516         int done;
517         int this_part;
518
519         data = filp->private_data;
520
521         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
522         if (!buffer)
523                 return -ENOMEM;
524
525         mutex_lock(&data->io_mutex);
526         if (data->zombie) {
527                 retval = -ENODEV;
528                 goto exit;
529         }
530
531         remaining = count;
532         done = 0;
533
534         while (remaining > 0) {
535                 if (remaining > USBTMC_SIZE_IOBUFFER - 12) {
536                         this_part = USBTMC_SIZE_IOBUFFER - 12;
537                         buffer[8] = 0;
538                 } else {
539                         this_part = remaining;
540                         buffer[8] = 1;
541                 }
542
543                 /* Setup IO buffer for DEV_DEP_MSG_OUT message */
544                 buffer[0] = 1;
545                 buffer[1] = data->bTag;
546                 buffer[2] = ~(data->bTag);
547                 buffer[3] = 0; /* Reserved */
548                 buffer[4] = this_part & 255;
549                 buffer[5] = (this_part >> 8) & 255;
550                 buffer[6] = (this_part >> 16) & 255;
551                 buffer[7] = (this_part >> 24) & 255;
552                 /* buffer[8] is set above... */
553                 buffer[9] = 0; /* Reserved */
554                 buffer[10] = 0; /* Reserved */
555                 buffer[11] = 0; /* Reserved */
556
557                 if (copy_from_user(&buffer[12], buf + done, this_part)) {
558                         retval = -EFAULT;
559                         goto exit;
560                 }
561
562                 n_bytes = roundup(12 + this_part, 4);
563                 memset(buffer + 12 + this_part, 0, n_bytes - (12 + this_part));
564
565                 retval = usb_bulk_msg(data->usb_dev,
566                                       usb_sndbulkpipe(data->usb_dev,
567                                                       data->bulk_out),
568                                       buffer, n_bytes, &actual, USBTMC_TIMEOUT);
569
570                 data->bTag_last_write = data->bTag;
571                 data->bTag++;
572
573                 if (!data->bTag)
574                         data->bTag++;
575
576                 if (retval < 0) {
577                         dev_err(&data->intf->dev,
578                                 "Unable to send data, error %d\n", retval);
579                         if (data->auto_abort)
580                                 usbtmc_ioctl_abort_bulk_out(data);
581                         goto exit;
582                 }
583
584                 remaining -= this_part;
585                 done += this_part;
586         }
587
588         retval = count;
589 exit:
590         mutex_unlock(&data->io_mutex);
591         kfree(buffer);
592         return retval;
593 }
594
595 static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
596 {
597         struct usb_host_interface *current_setting;
598         struct usb_endpoint_descriptor *desc;
599         struct device *dev;
600         u8 *buffer;
601         int rv;
602         int n;
603         int actual;
604         int max_size;
605
606         dev = &data->intf->dev;
607
608         dev_dbg(dev, "Sending INITIATE_CLEAR request\n");
609
610         buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
611         if (!buffer)
612                 return -ENOMEM;
613
614         rv = usb_control_msg(data->usb_dev,
615                              usb_rcvctrlpipe(data->usb_dev, 0),
616                              USBTMC_REQUEST_INITIATE_CLEAR,
617                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
618                              0, 0, buffer, 1, USBTMC_TIMEOUT);
619         if (rv < 0) {
620                 dev_err(dev, "usb_control_msg returned %d\n", rv);
621                 goto exit;
622         }
623
624         dev_dbg(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
625
626         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
627                 dev_err(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
628                 rv = -EPERM;
629                 goto exit;
630         }
631
632         max_size = 0;
633         current_setting = data->intf->cur_altsetting;
634         for (n = 0; n < current_setting->desc.bNumEndpoints; n++) {
635                 desc = &current_setting->endpoint[n].desc;
636                 if (desc->bEndpointAddress == data->bulk_in)
637                         max_size = le16_to_cpu(desc->wMaxPacketSize);
638         }
639
640         if (max_size == 0) {
641                 dev_err(dev, "Couldn't get wMaxPacketSize\n");
642                 rv = -EPERM;
643                 goto exit;
644         }
645
646         dev_dbg(dev, "wMaxPacketSize is %d\n", max_size);
647
648         n = 0;
649
650 usbtmc_clear_check_status:
651
652         dev_dbg(dev, "Sending CHECK_CLEAR_STATUS request\n");
653
654         rv = usb_control_msg(data->usb_dev,
655                              usb_rcvctrlpipe(data->usb_dev, 0),
656                              USBTMC_REQUEST_CHECK_CLEAR_STATUS,
657                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
658                              0, 0, buffer, 2, USBTMC_TIMEOUT);
659         if (rv < 0) {
660                 dev_err(dev, "usb_control_msg returned %d\n", rv);
661                 goto exit;
662         }
663
664         dev_dbg(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
665
666         if (buffer[0] == USBTMC_STATUS_SUCCESS)
667                 goto usbtmc_clear_bulk_out_halt;
668
669         if (buffer[0] != USBTMC_STATUS_PENDING) {
670                 dev_err(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
671                 rv = -EPERM;
672                 goto exit;
673         }
674
675         if (buffer[1] == 1)
676                 do {
677                         dev_dbg(dev, "Reading from bulk in EP\n");
678
679                         rv = usb_bulk_msg(data->usb_dev,
680                                           usb_rcvbulkpipe(data->usb_dev,
681                                                           data->bulk_in),
682                                           buffer, USBTMC_SIZE_IOBUFFER,
683                                           &actual, USBTMC_TIMEOUT);
684                         n++;
685
686                         if (rv < 0) {
687                                 dev_err(dev, "usb_control_msg returned %d\n",
688                                         rv);
689                                 goto exit;
690                         }
691                 } while ((actual == max_size) &&
692                           (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
693
694         if (actual == max_size) {
695                 dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
696                         USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
697                 rv = -EPERM;
698                 goto exit;
699         }
700
701         goto usbtmc_clear_check_status;
702
703 usbtmc_clear_bulk_out_halt:
704
705         rv = usb_control_msg(data->usb_dev,
706                              usb_sndctrlpipe(data->usb_dev, 0),
707                              USB_REQ_CLEAR_FEATURE,
708                              USB_DIR_OUT | USB_TYPE_STANDARD |
709                              USB_RECIP_ENDPOINT,
710                              USB_ENDPOINT_HALT,
711                              data->bulk_out, buffer, 0,
712                              USBTMC_TIMEOUT);
713         if (rv < 0) {
714                 dev_err(dev, "usb_control_msg returned %d\n", rv);
715                 goto exit;
716         }
717         rv = 0;
718
719 exit:
720         kfree(buffer);
721         return rv;
722 }
723
724 static int usbtmc_ioctl_clear_out_halt(struct usbtmc_device_data *data)
725 {
726         u8 *buffer;
727         int rv;
728
729         buffer = kmalloc(2, GFP_KERNEL);
730         if (!buffer)
731                 return -ENOMEM;
732
733         rv = usb_control_msg(data->usb_dev,
734                              usb_sndctrlpipe(data->usb_dev, 0),
735                              USB_REQ_CLEAR_FEATURE,
736                              USB_DIR_OUT | USB_TYPE_STANDARD |
737                              USB_RECIP_ENDPOINT,
738                              USB_ENDPOINT_HALT, data->bulk_out,
739                              buffer, 0, USBTMC_TIMEOUT);
740
741         if (rv < 0) {
742                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
743                         rv);
744                 goto exit;
745         }
746         rv = 0;
747
748 exit:
749         kfree(buffer);
750         return rv;
751 }
752
753 static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data)
754 {
755         u8 *buffer;
756         int rv;
757
758         buffer = kmalloc(2, GFP_KERNEL);
759         if (!buffer)
760                 return -ENOMEM;
761
762         rv = usb_control_msg(data->usb_dev, usb_sndctrlpipe(data->usb_dev, 0),
763                              USB_REQ_CLEAR_FEATURE,
764                              USB_DIR_OUT | USB_TYPE_STANDARD |
765                              USB_RECIP_ENDPOINT,
766                              USB_ENDPOINT_HALT, data->bulk_in, buffer, 0,
767                              USBTMC_TIMEOUT);
768
769         if (rv < 0) {
770                 dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
771                         rv);
772                 goto exit;
773         }
774         rv = 0;
775
776 exit:
777         kfree(buffer);
778         return rv;
779 }
780
781 static int get_capabilities(struct usbtmc_device_data *data)
782 {
783         struct device *dev = &data->usb_dev->dev;
784         char *buffer;
785         int rv = 0;
786
787         buffer = kmalloc(0x18, GFP_KERNEL);
788         if (!buffer)
789                 return -ENOMEM;
790
791         rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0),
792                              USBTMC_REQUEST_GET_CAPABILITIES,
793                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
794                              0, 0, buffer, 0x18, USBTMC_TIMEOUT);
795         if (rv < 0) {
796                 dev_err(dev, "usb_control_msg returned %d\n", rv);
797                 goto err_out;
798         }
799
800         dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
801         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
802                 dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
803                 rv = -EPERM;
804                 goto err_out;
805         }
806         dev_dbg(dev, "Interface capabilities are %x\n", buffer[4]);
807         dev_dbg(dev, "Device capabilities are %x\n", buffer[5]);
808         dev_dbg(dev, "USB488 interface capabilities are %x\n", buffer[14]);
809         dev_dbg(dev, "USB488 device capabilities are %x\n", buffer[15]);
810
811         data->capabilities.interface_capabilities = buffer[4];
812         data->capabilities.device_capabilities = buffer[5];
813         data->capabilities.usb488_interface_capabilities = buffer[14];
814         data->capabilities.usb488_device_capabilities = buffer[15];
815         rv = 0;
816
817 err_out:
818         kfree(buffer);
819         return rv;
820 }
821
822 #define capability_attribute(name)                                      \
823 static ssize_t show_##name(struct device *dev,                          \
824                            struct device_attribute *attr, char *buf)    \
825 {                                                                       \
826         struct usb_interface *intf = to_usb_interface(dev);             \
827         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
828                                                                         \
829         return sprintf(buf, "%d\n", data->capabilities.name);           \
830 }                                                                       \
831 static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
832
833 capability_attribute(interface_capabilities);
834 capability_attribute(device_capabilities);
835 capability_attribute(usb488_interface_capabilities);
836 capability_attribute(usb488_device_capabilities);
837
838 static struct attribute *capability_attrs[] = {
839         &dev_attr_interface_capabilities.attr,
840         &dev_attr_device_capabilities.attr,
841         &dev_attr_usb488_interface_capabilities.attr,
842         &dev_attr_usb488_device_capabilities.attr,
843         NULL,
844 };
845
846 static struct attribute_group capability_attr_grp = {
847         .attrs = capability_attrs,
848 };
849
850 static ssize_t show_TermChar(struct device *dev,
851                              struct device_attribute *attr, char *buf)
852 {
853         struct usb_interface *intf = to_usb_interface(dev);
854         struct usbtmc_device_data *data = usb_get_intfdata(intf);
855
856         return sprintf(buf, "%c\n", data->TermChar);
857 }
858
859 static ssize_t store_TermChar(struct device *dev,
860                               struct device_attribute *attr,
861                               const char *buf, size_t count)
862 {
863         struct usb_interface *intf = to_usb_interface(dev);
864         struct usbtmc_device_data *data = usb_get_intfdata(intf);
865
866         if (count < 1)
867                 return -EINVAL;
868         data->TermChar = buf[0];
869         return count;
870 }
871 static DEVICE_ATTR(TermChar, S_IRUGO, show_TermChar, store_TermChar);
872
873 #define data_attribute(name)                                            \
874 static ssize_t show_##name(struct device *dev,                          \
875                            struct device_attribute *attr, char *buf)    \
876 {                                                                       \
877         struct usb_interface *intf = to_usb_interface(dev);             \
878         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
879                                                                         \
880         return sprintf(buf, "%d\n", data->name);                        \
881 }                                                                       \
882 static ssize_t store_##name(struct device *dev,                         \
883                             struct device_attribute *attr,              \
884                             const char *buf, size_t count)              \
885 {                                                                       \
886         struct usb_interface *intf = to_usb_interface(dev);             \
887         struct usbtmc_device_data *data = usb_get_intfdata(intf);       \
888         ssize_t result;                                                 \
889         unsigned val;                                                   \
890                                                                         \
891         result = sscanf(buf, "%u\n", &val);                             \
892         if (result != 1)                                                \
893                 result = -EINVAL;                                       \
894         data->name = val;                                               \
895         if (result < 0)                                                 \
896                 return result;                                          \
897         else                                                            \
898                 return count;                                           \
899 }                                                                       \
900 static DEVICE_ATTR(name, S_IRUGO, show_##name, store_##name)
901
902 data_attribute(TermCharEnabled);
903 data_attribute(auto_abort);
904
905 static struct attribute *data_attrs[] = {
906         &dev_attr_TermChar.attr,
907         &dev_attr_TermCharEnabled.attr,
908         &dev_attr_auto_abort.attr,
909         NULL,
910 };
911
912 static struct attribute_group data_attr_grp = {
913         .attrs = data_attrs,
914 };
915
916 static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
917 {
918         struct device *dev;
919         u8 *buffer;
920         int rv;
921
922         dev = &data->intf->dev;
923
924         buffer = kmalloc(2, GFP_KERNEL);
925         if (!buffer)
926                 return -ENOMEM;
927
928         rv = usb_control_msg(data->usb_dev,
929                              usb_rcvctrlpipe(data->usb_dev, 0),
930                              USBTMC_REQUEST_INDICATOR_PULSE,
931                              USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
932                              0, 0, buffer, 0x01, USBTMC_TIMEOUT);
933
934         if (rv < 0) {
935                 dev_err(dev, "usb_control_msg returned %d\n", rv);
936                 goto exit;
937         }
938
939         dev_dbg(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
940
941         if (buffer[0] != USBTMC_STATUS_SUCCESS) {
942                 dev_err(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
943                 rv = -EPERM;
944                 goto exit;
945         }
946         rv = 0;
947
948 exit:
949         kfree(buffer);
950         return rv;
951 }
952
953 static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
954 {
955         struct usbtmc_device_data *data;
956         int retval = -EBADRQC;
957
958         data = file->private_data;
959         mutex_lock(&data->io_mutex);
960         if (data->zombie) {
961                 retval = -ENODEV;
962                 goto skip_io_on_zombie;
963         }
964
965         switch (cmd) {
966         case USBTMC_IOCTL_CLEAR_OUT_HALT:
967                 retval = usbtmc_ioctl_clear_out_halt(data);
968                 break;
969
970         case USBTMC_IOCTL_CLEAR_IN_HALT:
971                 retval = usbtmc_ioctl_clear_in_halt(data);
972                 break;
973
974         case USBTMC_IOCTL_INDICATOR_PULSE:
975                 retval = usbtmc_ioctl_indicator_pulse(data);
976                 break;
977
978         case USBTMC_IOCTL_CLEAR:
979                 retval = usbtmc_ioctl_clear(data);
980                 break;
981
982         case USBTMC_IOCTL_ABORT_BULK_OUT:
983                 retval = usbtmc_ioctl_abort_bulk_out(data);
984                 break;
985
986         case USBTMC_IOCTL_ABORT_BULK_IN:
987                 retval = usbtmc_ioctl_abort_bulk_in(data);
988                 break;
989         }
990
991 skip_io_on_zombie:
992         mutex_unlock(&data->io_mutex);
993         return retval;
994 }
995
996 static const struct file_operations fops = {
997         .owner          = THIS_MODULE,
998         .read           = usbtmc_read,
999         .write          = usbtmc_write,
1000         .open           = usbtmc_open,
1001         .release        = usbtmc_release,
1002         .unlocked_ioctl = usbtmc_ioctl,
1003 };
1004
1005 static struct usb_class_driver usbtmc_class = {
1006         .name =         "usbtmc%d",
1007         .fops =         &fops,
1008         .minor_base =   USBTMC_MINOR_BASE,
1009 };
1010
1011
1012 static int usbtmc_probe(struct usb_interface *intf,
1013                         const struct usb_device_id *id)
1014 {
1015         struct usbtmc_device_data *data;
1016         struct usb_host_interface *iface_desc;
1017         struct usb_endpoint_descriptor *endpoint;
1018         int n;
1019         int retcode;
1020
1021         dev_dbg(&intf->dev, "%s called\n", __func__);
1022
1023         data = kmalloc(sizeof(struct usbtmc_device_data), GFP_KERNEL);
1024         if (!data) {
1025                 dev_err(&intf->dev, "Unable to allocate kernel memory\n");
1026                 return -ENOMEM;
1027         }
1028
1029         data->intf = intf;
1030         data->id = id;
1031         data->usb_dev = usb_get_dev(interface_to_usbdev(intf));
1032         usb_set_intfdata(intf, data);
1033         kref_init(&data->kref);
1034         mutex_init(&data->io_mutex);
1035         data->zombie = 0;
1036
1037         /* Initialize USBTMC bTag and other fields */
1038         data->bTag      = 1;
1039         data->TermCharEnabled = 0;
1040         data->TermChar = '\n';
1041
1042         /* USBTMC devices have only one setting, so use that */
1043         iface_desc = data->intf->cur_altsetting;
1044
1045         /* Find bulk in endpoint */
1046         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1047                 endpoint = &iface_desc->endpoint[n].desc;
1048
1049                 if (usb_endpoint_is_bulk_in(endpoint)) {
1050                         data->bulk_in = endpoint->bEndpointAddress;
1051                         dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n",
1052                                 data->bulk_in);
1053                         break;
1054                 }
1055         }
1056
1057         /* Find bulk out endpoint */
1058         for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1059                 endpoint = &iface_desc->endpoint[n].desc;
1060
1061                 if (usb_endpoint_is_bulk_out(endpoint)) {
1062                         data->bulk_out = endpoint->bEndpointAddress;
1063                         dev_dbg(&intf->dev, "Found Bulk out endpoint at %u\n",
1064                                 data->bulk_out);
1065                         break;
1066                 }
1067         }
1068
1069         retcode = get_capabilities(data);
1070         if (retcode)
1071                 dev_err(&intf->dev, "can't read capabilities\n");
1072         else
1073                 retcode = sysfs_create_group(&intf->dev.kobj,
1074                                              &capability_attr_grp);
1075
1076         retcode = sysfs_create_group(&intf->dev.kobj, &data_attr_grp);
1077
1078         retcode = usb_register_dev(intf, &usbtmc_class);
1079         if (retcode) {
1080                 dev_err(&intf->dev, "Not able to get a minor"
1081                         " (base %u, slice default): %d\n", USBTMC_MINOR_BASE,
1082                         retcode);
1083                 goto error_register;
1084         }
1085         dev_dbg(&intf->dev, "Using minor number %d\n", intf->minor);
1086
1087         return 0;
1088
1089 error_register:
1090         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1091         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1092         kref_put(&data->kref, usbtmc_delete);
1093         return retcode;
1094 }
1095
1096 static void usbtmc_disconnect(struct usb_interface *intf)
1097 {
1098         struct usbtmc_device_data *data;
1099
1100         dev_dbg(&intf->dev, "usbtmc_disconnect called\n");
1101
1102         data = usb_get_intfdata(intf);
1103         usb_deregister_dev(intf, &usbtmc_class);
1104         sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1105         sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1106         mutex_lock(&data->io_mutex);
1107         data->zombie = 1;
1108         mutex_unlock(&data->io_mutex);
1109         kref_put(&data->kref, usbtmc_delete);
1110 }
1111
1112 static int usbtmc_suspend (struct usb_interface *intf, pm_message_t message)
1113 {
1114         /* this driver does not have pending URBs */
1115         return 0;
1116 }
1117
1118 static int usbtmc_resume (struct usb_interface *intf)
1119 {
1120         return 0;
1121 }
1122
1123 static struct usb_driver usbtmc_driver = {
1124         .name           = "usbtmc",
1125         .id_table       = usbtmc_devices,
1126         .probe          = usbtmc_probe,
1127         .disconnect     = usbtmc_disconnect,
1128         .suspend        = usbtmc_suspend,
1129         .resume         = usbtmc_resume,
1130 };
1131
1132 static int __init usbtmc_init(void)
1133 {
1134         int retcode;
1135
1136         retcode = usb_register(&usbtmc_driver);
1137         if (retcode)
1138                 printk(KERN_ERR KBUILD_MODNAME": Unable to register driver\n");
1139         return retcode;
1140 }
1141 module_init(usbtmc_init);
1142
1143 static void __exit usbtmc_exit(void)
1144 {
1145         usb_deregister(&usbtmc_driver);
1146 }
1147 module_exit(usbtmc_exit);
1148
1149 MODULE_LICENSE("GPL");