xref: /openbmc/linux/drivers/usb/class/usbtmc.c (revision de2bdb3d)
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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
23 
24 #include <linux/module.h>
25 #include <linux/kernel.h>
26 #include <linux/fs.h>
27 #include <linux/uaccess.h>
28 #include <linux/kref.h>
29 #include <linux/slab.h>
30 #include <linux/poll.h>
31 #include <linux/mutex.h>
32 #include <linux/usb.h>
33 #include <linux/usb/tmc.h>
34 
35 
36 #define RIGOL			1
37 #define USBTMC_HEADER_SIZE	12
38 #define USBTMC_MINOR_BASE	176
39 
40 /*
41  * Size of driver internal IO buffer. Must be multiple of 4 and at least as
42  * large as wMaxPacketSize (which is usually 512 bytes).
43  */
44 #define USBTMC_SIZE_IOBUFFER	2048
45 
46 /* Default USB timeout (in milliseconds) */
47 #define USBTMC_TIMEOUT		5000
48 
49 /*
50  * Maximum number of read cycles to empty bulk in endpoint during CLEAR and
51  * ABORT_BULK_IN requests. Ends the loop if (for whatever reason) a short
52  * packet is never read.
53  */
54 #define USBTMC_MAX_READS_TO_CLEAR_BULK_IN	100
55 
56 static const struct usb_device_id usbtmc_devices[] = {
57 	{ USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 0), },
58 	{ USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 1), },
59 	{ 0, } /* terminating entry */
60 };
61 MODULE_DEVICE_TABLE(usb, usbtmc_devices);
62 
63 /*
64  * This structure is the capabilities for the device
65  * See section 4.2.1.8 of the USBTMC specification,
66  * and section 4.2.2 of the USBTMC usb488 subclass
67  * specification for details.
68  */
69 struct usbtmc_dev_capabilities {
70 	__u8 interface_capabilities;
71 	__u8 device_capabilities;
72 	__u8 usb488_interface_capabilities;
73 	__u8 usb488_device_capabilities;
74 };
75 
76 /* This structure holds private data for each USBTMC device. One copy is
77  * allocated for each USBTMC device in the driver's probe function.
78  */
79 struct usbtmc_device_data {
80 	const struct usb_device_id *id;
81 	struct usb_device *usb_dev;
82 	struct usb_interface *intf;
83 
84 	unsigned int bulk_in;
85 	unsigned int bulk_out;
86 
87 	u8 bTag;
88 	u8 bTag_last_write;	/* needed for abort */
89 	u8 bTag_last_read;	/* needed for abort */
90 
91 	/* data for interrupt in endpoint handling */
92 	u8             bNotify1;
93 	u8             bNotify2;
94 	u16            ifnum;
95 	u8             iin_bTag;
96 	u8            *iin_buffer;
97 	atomic_t       iin_data_valid;
98 	unsigned int   iin_ep;
99 	int            iin_ep_present;
100 	int            iin_interval;
101 	struct urb    *iin_urb;
102 	u16            iin_wMaxPacketSize;
103 	atomic_t       srq_asserted;
104 
105 	/* coalesced usb488_caps from usbtmc_dev_capabilities */
106 	__u8 usb488_caps;
107 
108 	u8 rigol_quirk;
109 
110 	/* attributes from the USB TMC spec for this device */
111 	u8 TermChar;
112 	bool TermCharEnabled;
113 	bool auto_abort;
114 
115 	bool zombie; /* fd of disconnected device */
116 
117 	struct usbtmc_dev_capabilities	capabilities;
118 	struct kref kref;
119 	struct mutex io_mutex;	/* only one i/o function running at a time */
120 	wait_queue_head_t waitq;
121 	struct fasync_struct *fasync;
122 };
123 #define to_usbtmc_data(d) container_of(d, struct usbtmc_device_data, kref)
124 
125 struct usbtmc_ID_rigol_quirk {
126 	__u16 idVendor;
127 	__u16 idProduct;
128 };
129 
130 static const struct usbtmc_ID_rigol_quirk usbtmc_id_quirk[] = {
131 	{ 0x1ab1, 0x0588 },
132 	{ 0x1ab1, 0x04b0 },
133 	{ 0, 0 }
134 };
135 
136 /* Forward declarations */
137 static struct usb_driver usbtmc_driver;
138 
139 static void usbtmc_delete(struct kref *kref)
140 {
141 	struct usbtmc_device_data *data = to_usbtmc_data(kref);
142 
143 	usb_put_dev(data->usb_dev);
144 	kfree(data);
145 }
146 
147 static int usbtmc_open(struct inode *inode, struct file *filp)
148 {
149 	struct usb_interface *intf;
150 	struct usbtmc_device_data *data;
151 	int retval = 0;
152 
153 	intf = usb_find_interface(&usbtmc_driver, iminor(inode));
154 	if (!intf) {
155 		pr_err("can not find device for minor %d", iminor(inode));
156 		return -ENODEV;
157 	}
158 
159 	data = usb_get_intfdata(intf);
160 	kref_get(&data->kref);
161 
162 	/* Store pointer in file structure's private data field */
163 	filp->private_data = data;
164 
165 	return retval;
166 }
167 
168 static int usbtmc_release(struct inode *inode, struct file *file)
169 {
170 	struct usbtmc_device_data *data = file->private_data;
171 
172 	kref_put(&data->kref, usbtmc_delete);
173 	return 0;
174 }
175 
176 static int usbtmc_ioctl_abort_bulk_in(struct usbtmc_device_data *data)
177 {
178 	u8 *buffer;
179 	struct device *dev;
180 	int rv;
181 	int n;
182 	int actual;
183 	struct usb_host_interface *current_setting;
184 	int max_size;
185 
186 	dev = &data->intf->dev;
187 	buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
188 	if (!buffer)
189 		return -ENOMEM;
190 
191 	rv = usb_control_msg(data->usb_dev,
192 			     usb_rcvctrlpipe(data->usb_dev, 0),
193 			     USBTMC_REQUEST_INITIATE_ABORT_BULK_IN,
194 			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
195 			     data->bTag_last_read, data->bulk_in,
196 			     buffer, 2, USBTMC_TIMEOUT);
197 
198 	if (rv < 0) {
199 		dev_err(dev, "usb_control_msg returned %d\n", rv);
200 		goto exit;
201 	}
202 
203 	dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
204 
205 	if (buffer[0] == USBTMC_STATUS_FAILED) {
206 		rv = 0;
207 		goto exit;
208 	}
209 
210 	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
211 		dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n",
212 			buffer[0]);
213 		rv = -EPERM;
214 		goto exit;
215 	}
216 
217 	max_size = 0;
218 	current_setting = data->intf->cur_altsetting;
219 	for (n = 0; n < current_setting->desc.bNumEndpoints; n++)
220 		if (current_setting->endpoint[n].desc.bEndpointAddress ==
221 			data->bulk_in)
222 			max_size = usb_endpoint_maxp(&current_setting->endpoint[n].desc);
223 
224 	if (max_size == 0) {
225 		dev_err(dev, "Couldn't get wMaxPacketSize\n");
226 		rv = -EPERM;
227 		goto exit;
228 	}
229 
230 	dev_dbg(&data->intf->dev, "wMaxPacketSize is %d\n", max_size);
231 
232 	n = 0;
233 
234 	do {
235 		dev_dbg(dev, "Reading from bulk in EP\n");
236 
237 		rv = usb_bulk_msg(data->usb_dev,
238 				  usb_rcvbulkpipe(data->usb_dev,
239 						  data->bulk_in),
240 				  buffer, USBTMC_SIZE_IOBUFFER,
241 				  &actual, USBTMC_TIMEOUT);
242 
243 		n++;
244 
245 		if (rv < 0) {
246 			dev_err(dev, "usb_bulk_msg returned %d\n", rv);
247 			goto exit;
248 		}
249 	} while ((actual == max_size) &&
250 		 (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
251 
252 	if (actual == max_size) {
253 		dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
254 			USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
255 		rv = -EPERM;
256 		goto exit;
257 	}
258 
259 	n = 0;
260 
261 usbtmc_abort_bulk_in_status:
262 	rv = usb_control_msg(data->usb_dev,
263 			     usb_rcvctrlpipe(data->usb_dev, 0),
264 			     USBTMC_REQUEST_CHECK_ABORT_BULK_IN_STATUS,
265 			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
266 			     0, data->bulk_in, buffer, 0x08,
267 			     USBTMC_TIMEOUT);
268 
269 	if (rv < 0) {
270 		dev_err(dev, "usb_control_msg returned %d\n", rv);
271 		goto exit;
272 	}
273 
274 	dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
275 
276 	if (buffer[0] == USBTMC_STATUS_SUCCESS) {
277 		rv = 0;
278 		goto exit;
279 	}
280 
281 	if (buffer[0] != USBTMC_STATUS_PENDING) {
282 		dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
283 		rv = -EPERM;
284 		goto exit;
285 	}
286 
287 	if (buffer[1] == 1)
288 		do {
289 			dev_dbg(dev, "Reading from bulk in EP\n");
290 
291 			rv = usb_bulk_msg(data->usb_dev,
292 					  usb_rcvbulkpipe(data->usb_dev,
293 							  data->bulk_in),
294 					  buffer, USBTMC_SIZE_IOBUFFER,
295 					  &actual, USBTMC_TIMEOUT);
296 
297 			n++;
298 
299 			if (rv < 0) {
300 				dev_err(dev, "usb_bulk_msg returned %d\n", rv);
301 				goto exit;
302 			}
303 		} while ((actual == max_size) &&
304 			 (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
305 
306 	if (actual == max_size) {
307 		dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
308 			USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
309 		rv = -EPERM;
310 		goto exit;
311 	}
312 
313 	goto usbtmc_abort_bulk_in_status;
314 
315 exit:
316 	kfree(buffer);
317 	return rv;
318 
319 }
320 
321 static int usbtmc_ioctl_abort_bulk_out(struct usbtmc_device_data *data)
322 {
323 	struct device *dev;
324 	u8 *buffer;
325 	int rv;
326 	int n;
327 
328 	dev = &data->intf->dev;
329 
330 	buffer = kmalloc(8, GFP_KERNEL);
331 	if (!buffer)
332 		return -ENOMEM;
333 
334 	rv = usb_control_msg(data->usb_dev,
335 			     usb_rcvctrlpipe(data->usb_dev, 0),
336 			     USBTMC_REQUEST_INITIATE_ABORT_BULK_OUT,
337 			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
338 			     data->bTag_last_write, data->bulk_out,
339 			     buffer, 2, USBTMC_TIMEOUT);
340 
341 	if (rv < 0) {
342 		dev_err(dev, "usb_control_msg returned %d\n", rv);
343 		goto exit;
344 	}
345 
346 	dev_dbg(dev, "INITIATE_ABORT_BULK_OUT returned %x\n", buffer[0]);
347 
348 	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
349 		dev_err(dev, "INITIATE_ABORT_BULK_OUT returned %x\n",
350 			buffer[0]);
351 		rv = -EPERM;
352 		goto exit;
353 	}
354 
355 	n = 0;
356 
357 usbtmc_abort_bulk_out_check_status:
358 	rv = usb_control_msg(data->usb_dev,
359 			     usb_rcvctrlpipe(data->usb_dev, 0),
360 			     USBTMC_REQUEST_CHECK_ABORT_BULK_OUT_STATUS,
361 			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
362 			     0, data->bulk_out, buffer, 0x08,
363 			     USBTMC_TIMEOUT);
364 	n++;
365 	if (rv < 0) {
366 		dev_err(dev, "usb_control_msg returned %d\n", rv);
367 		goto exit;
368 	}
369 
370 	dev_dbg(dev, "CHECK_ABORT_BULK_OUT returned %x\n", buffer[0]);
371 
372 	if (buffer[0] == USBTMC_STATUS_SUCCESS)
373 		goto usbtmc_abort_bulk_out_clear_halt;
374 
375 	if ((buffer[0] == USBTMC_STATUS_PENDING) &&
376 	    (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN))
377 		goto usbtmc_abort_bulk_out_check_status;
378 
379 	rv = -EPERM;
380 	goto exit;
381 
382 usbtmc_abort_bulk_out_clear_halt:
383 	rv = usb_clear_halt(data->usb_dev,
384 			    usb_sndbulkpipe(data->usb_dev, data->bulk_out));
385 
386 	if (rv < 0) {
387 		dev_err(dev, "usb_control_msg returned %d\n", rv);
388 		goto exit;
389 	}
390 	rv = 0;
391 
392 exit:
393 	kfree(buffer);
394 	return rv;
395 }
396 
397 static int usbtmc488_ioctl_read_stb(struct usbtmc_device_data *data,
398 				void __user *arg)
399 {
400 	struct device *dev = &data->intf->dev;
401 	u8 *buffer;
402 	u8 tag;
403 	__u8 stb;
404 	int rv;
405 
406 	dev_dbg(dev, "Enter ioctl_read_stb iin_ep_present: %d\n",
407 		data->iin_ep_present);
408 
409 	buffer = kmalloc(8, GFP_KERNEL);
410 	if (!buffer)
411 		return -ENOMEM;
412 
413 	atomic_set(&data->iin_data_valid, 0);
414 
415 	/* must issue read_stb before using poll or select */
416 	atomic_set(&data->srq_asserted, 0);
417 
418 	rv = usb_control_msg(data->usb_dev,
419 			usb_rcvctrlpipe(data->usb_dev, 0),
420 			USBTMC488_REQUEST_READ_STATUS_BYTE,
421 			USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
422 			data->iin_bTag,
423 			data->ifnum,
424 			buffer, 0x03, USBTMC_TIMEOUT);
425 	if (rv < 0) {
426 		dev_err(dev, "stb usb_control_msg returned %d\n", rv);
427 		goto exit;
428 	}
429 
430 	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
431 		dev_err(dev, "control status returned %x\n", buffer[0]);
432 		rv = -EIO;
433 		goto exit;
434 	}
435 
436 	if (data->iin_ep_present) {
437 		rv = wait_event_interruptible_timeout(
438 			data->waitq,
439 			atomic_read(&data->iin_data_valid) != 0,
440 			USBTMC_TIMEOUT);
441 		if (rv < 0) {
442 			dev_dbg(dev, "wait interrupted %d\n", rv);
443 			goto exit;
444 		}
445 
446 		if (rv == 0) {
447 			dev_dbg(dev, "wait timed out\n");
448 			rv = -ETIME;
449 			goto exit;
450 		}
451 
452 		tag = data->bNotify1 & 0x7f;
453 		if (tag != data->iin_bTag) {
454 			dev_err(dev, "expected bTag %x got %x\n",
455 				data->iin_bTag, tag);
456 		}
457 
458 		stb = data->bNotify2;
459 	} else {
460 		stb = buffer[2];
461 	}
462 
463 	rv = copy_to_user(arg, &stb, sizeof(stb));
464 	if (rv)
465 		rv = -EFAULT;
466 
467  exit:
468 	/* bump interrupt bTag */
469 	data->iin_bTag += 1;
470 	if (data->iin_bTag > 127)
471 		/* 1 is for SRQ see USBTMC-USB488 subclass spec section 4.3.1 */
472 		data->iin_bTag = 2;
473 
474 	kfree(buffer);
475 	return rv;
476 }
477 
478 static int usbtmc488_ioctl_simple(struct usbtmc_device_data *data,
479 				void __user *arg, unsigned int cmd)
480 {
481 	struct device *dev = &data->intf->dev;
482 	__u8 val;
483 	u8 *buffer;
484 	u16 wValue;
485 	int rv;
486 
487 	if (!(data->usb488_caps & USBTMC488_CAPABILITY_SIMPLE))
488 		return -EINVAL;
489 
490 	buffer = kmalloc(8, GFP_KERNEL);
491 	if (!buffer)
492 		return -ENOMEM;
493 
494 	if (cmd == USBTMC488_REQUEST_REN_CONTROL) {
495 		rv = copy_from_user(&val, arg, sizeof(val));
496 		if (rv) {
497 			rv = -EFAULT;
498 			goto exit;
499 		}
500 		wValue = val ? 1 : 0;
501 	} else {
502 		wValue = 0;
503 	}
504 
505 	rv = usb_control_msg(data->usb_dev,
506 			usb_rcvctrlpipe(data->usb_dev, 0),
507 			cmd,
508 			USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
509 			wValue,
510 			data->ifnum,
511 			buffer, 0x01, USBTMC_TIMEOUT);
512 	if (rv < 0) {
513 		dev_err(dev, "simple usb_control_msg failed %d\n", rv);
514 		goto exit;
515 	} else if (rv != 1) {
516 		dev_warn(dev, "simple usb_control_msg returned %d\n", rv);
517 		rv = -EIO;
518 		goto exit;
519 	}
520 
521 	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
522 		dev_err(dev, "simple control status returned %x\n", buffer[0]);
523 		rv = -EIO;
524 		goto exit;
525 	}
526 	rv = 0;
527 
528  exit:
529 	kfree(buffer);
530 	return rv;
531 }
532 
533 /*
534  * Sends a REQUEST_DEV_DEP_MSG_IN message on the Bulk-IN endpoint.
535  * @transfer_size: number of bytes to request from the device.
536  *
537  * See the USBTMC specification, Table 4.
538  *
539  * Also updates bTag_last_write.
540  */
541 static int send_request_dev_dep_msg_in(struct usbtmc_device_data *data, size_t transfer_size)
542 {
543 	int retval;
544 	u8 *buffer;
545 	int actual;
546 
547 	buffer = kmalloc(USBTMC_HEADER_SIZE, GFP_KERNEL);
548 	if (!buffer)
549 		return -ENOMEM;
550 	/* Setup IO buffer for REQUEST_DEV_DEP_MSG_IN message
551 	 * Refer to class specs for details
552 	 */
553 	buffer[0] = 2;
554 	buffer[1] = data->bTag;
555 	buffer[2] = ~data->bTag;
556 	buffer[3] = 0; /* Reserved */
557 	buffer[4] = transfer_size >> 0;
558 	buffer[5] = transfer_size >> 8;
559 	buffer[6] = transfer_size >> 16;
560 	buffer[7] = transfer_size >> 24;
561 	buffer[8] = data->TermCharEnabled * 2;
562 	/* Use term character? */
563 	buffer[9] = data->TermChar;
564 	buffer[10] = 0; /* Reserved */
565 	buffer[11] = 0; /* Reserved */
566 
567 	/* Send bulk URB */
568 	retval = usb_bulk_msg(data->usb_dev,
569 			      usb_sndbulkpipe(data->usb_dev,
570 					      data->bulk_out),
571 			      buffer, USBTMC_HEADER_SIZE, &actual, USBTMC_TIMEOUT);
572 
573 	/* Store bTag (in case we need to abort) */
574 	data->bTag_last_write = data->bTag;
575 
576 	/* Increment bTag -- and increment again if zero */
577 	data->bTag++;
578 	if (!data->bTag)
579 		data->bTag++;
580 
581 	kfree(buffer);
582 	if (retval < 0) {
583 		dev_err(&data->intf->dev, "usb_bulk_msg in send_request_dev_dep_msg_in() returned %d\n", retval);
584 		return retval;
585 	}
586 
587 	return 0;
588 }
589 
590 static ssize_t usbtmc_read(struct file *filp, char __user *buf,
591 			   size_t count, loff_t *f_pos)
592 {
593 	struct usbtmc_device_data *data;
594 	struct device *dev;
595 	u32 n_characters;
596 	u8 *buffer;
597 	int actual;
598 	size_t done;
599 	size_t remaining;
600 	int retval;
601 	size_t this_part;
602 
603 	/* Get pointer to private data structure */
604 	data = filp->private_data;
605 	dev = &data->intf->dev;
606 
607 	buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
608 	if (!buffer)
609 		return -ENOMEM;
610 
611 	mutex_lock(&data->io_mutex);
612 	if (data->zombie) {
613 		retval = -ENODEV;
614 		goto exit;
615 	}
616 
617 	if (data->rigol_quirk) {
618 		dev_dbg(dev, "usb_bulk_msg_in: count(%zu)\n", count);
619 
620 		retval = send_request_dev_dep_msg_in(data, count);
621 
622 		if (retval < 0) {
623 			if (data->auto_abort)
624 				usbtmc_ioctl_abort_bulk_out(data);
625 			goto exit;
626 		}
627 	}
628 
629 	/* Loop until we have fetched everything we requested */
630 	remaining = count;
631 	this_part = remaining;
632 	done = 0;
633 
634 	while (remaining > 0) {
635 		if (!data->rigol_quirk) {
636 			dev_dbg(dev, "usb_bulk_msg_in: remaining(%zu), count(%zu)\n", remaining, count);
637 
638 			if (remaining > USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE - 3)
639 				this_part = USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE - 3;
640 			else
641 				this_part = remaining;
642 
643 			retval = send_request_dev_dep_msg_in(data, this_part);
644 			if (retval < 0) {
645 			dev_err(dev, "usb_bulk_msg returned %d\n", retval);
646 				if (data->auto_abort)
647 					usbtmc_ioctl_abort_bulk_out(data);
648 				goto exit;
649 			}
650 		}
651 
652 		/* Send bulk URB */
653 		retval = usb_bulk_msg(data->usb_dev,
654 				      usb_rcvbulkpipe(data->usb_dev,
655 						      data->bulk_in),
656 				      buffer, USBTMC_SIZE_IOBUFFER, &actual,
657 				      USBTMC_TIMEOUT);
658 
659 		dev_dbg(dev, "usb_bulk_msg: retval(%u), done(%zu), remaining(%zu), actual(%d)\n", retval, done, remaining, actual);
660 
661 		/* Store bTag (in case we need to abort) */
662 		data->bTag_last_read = data->bTag;
663 
664 		if (retval < 0) {
665 			dev_dbg(dev, "Unable to read data, error %d\n", retval);
666 			if (data->auto_abort)
667 				usbtmc_ioctl_abort_bulk_in(data);
668 			goto exit;
669 		}
670 
671 		/* Parse header in first packet */
672 		if ((done == 0) || !data->rigol_quirk) {
673 			/* Sanity checks for the header */
674 			if (actual < USBTMC_HEADER_SIZE) {
675 				dev_err(dev, "Device sent too small first packet: %u < %u\n", actual, USBTMC_HEADER_SIZE);
676 				if (data->auto_abort)
677 					usbtmc_ioctl_abort_bulk_in(data);
678 				goto exit;
679 			}
680 
681 			if (buffer[0] != 2) {
682 				dev_err(dev, "Device sent reply with wrong MsgID: %u != 2\n", buffer[0]);
683 				if (data->auto_abort)
684 					usbtmc_ioctl_abort_bulk_in(data);
685 				goto exit;
686 			}
687 
688 			if (buffer[1] != data->bTag_last_write) {
689 				dev_err(dev, "Device sent reply with wrong bTag: %u != %u\n", buffer[1], data->bTag_last_write);
690 				if (data->auto_abort)
691 					usbtmc_ioctl_abort_bulk_in(data);
692 				goto exit;
693 			}
694 
695 			/* How many characters did the instrument send? */
696 			n_characters = buffer[4] +
697 				       (buffer[5] << 8) +
698 				       (buffer[6] << 16) +
699 				       (buffer[7] << 24);
700 
701 			if (n_characters > this_part) {
702 				dev_err(dev, "Device wants to return more data than requested: %u > %zu\n", n_characters, count);
703 				if (data->auto_abort)
704 					usbtmc_ioctl_abort_bulk_in(data);
705 				goto exit;
706 			}
707 
708 			/* Remove the USBTMC header */
709 			actual -= USBTMC_HEADER_SIZE;
710 
711 			/* Check if the message is smaller than requested */
712 			if (data->rigol_quirk) {
713 				if (remaining > n_characters)
714 					remaining = n_characters;
715 				/* Remove padding if it exists */
716 				if (actual > remaining)
717 					actual = remaining;
718 			}
719 			else {
720 				if (this_part > n_characters)
721 					this_part = n_characters;
722 				/* Remove padding if it exists */
723 				if (actual > this_part)
724 					actual = this_part;
725 			}
726 
727 			dev_dbg(dev, "Bulk-IN header: N_characters(%u), bTransAttr(%u)\n", n_characters, buffer[8]);
728 
729 			remaining -= actual;
730 
731 			/* Terminate if end-of-message bit received from device */
732 			if ((buffer[8] & 0x01) && (actual >= n_characters))
733 				remaining = 0;
734 
735 			dev_dbg(dev, "Bulk-IN header: remaining(%zu), buf(%p), buffer(%p) done(%zu)\n", remaining,buf,buffer,done);
736 
737 
738 			/* Copy buffer to user space */
739 			if (copy_to_user(buf + done, &buffer[USBTMC_HEADER_SIZE], actual)) {
740 				/* There must have been an addressing problem */
741 				retval = -EFAULT;
742 				goto exit;
743 			}
744 			done += actual;
745 		}
746 		else  {
747 			if (actual > remaining)
748 				actual = remaining;
749 
750 			remaining -= actual;
751 
752 			dev_dbg(dev, "Bulk-IN header cont: actual(%u), done(%zu), remaining(%zu), buf(%p), buffer(%p)\n", actual, done, remaining,buf,buffer);
753 
754 			/* Copy buffer to user space */
755 			if (copy_to_user(buf + done, buffer, actual)) {
756 				/* There must have been an addressing problem */
757 				retval = -EFAULT;
758 				goto exit;
759 			}
760 			done += actual;
761 		}
762 	}
763 
764 	/* Update file position value */
765 	*f_pos = *f_pos + done;
766 	retval = done;
767 
768 exit:
769 	mutex_unlock(&data->io_mutex);
770 	kfree(buffer);
771 	return retval;
772 }
773 
774 static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
775 			    size_t count, loff_t *f_pos)
776 {
777 	struct usbtmc_device_data *data;
778 	u8 *buffer;
779 	int retval;
780 	int actual;
781 	unsigned long int n_bytes;
782 	int remaining;
783 	int done;
784 	int this_part;
785 
786 	data = filp->private_data;
787 
788 	buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
789 	if (!buffer)
790 		return -ENOMEM;
791 
792 	mutex_lock(&data->io_mutex);
793 	if (data->zombie) {
794 		retval = -ENODEV;
795 		goto exit;
796 	}
797 
798 	remaining = count;
799 	done = 0;
800 
801 	while (remaining > 0) {
802 		if (remaining > USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE) {
803 			this_part = USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE;
804 			buffer[8] = 0;
805 		} else {
806 			this_part = remaining;
807 			buffer[8] = 1;
808 		}
809 
810 		/* Setup IO buffer for DEV_DEP_MSG_OUT message */
811 		buffer[0] = 1;
812 		buffer[1] = data->bTag;
813 		buffer[2] = ~data->bTag;
814 		buffer[3] = 0; /* Reserved */
815 		buffer[4] = this_part >> 0;
816 		buffer[5] = this_part >> 8;
817 		buffer[6] = this_part >> 16;
818 		buffer[7] = this_part >> 24;
819 		/* buffer[8] is set above... */
820 		buffer[9] = 0; /* Reserved */
821 		buffer[10] = 0; /* Reserved */
822 		buffer[11] = 0; /* Reserved */
823 
824 		if (copy_from_user(&buffer[USBTMC_HEADER_SIZE], buf + done, this_part)) {
825 			retval = -EFAULT;
826 			goto exit;
827 		}
828 
829 		n_bytes = roundup(USBTMC_HEADER_SIZE + this_part, 4);
830 		memset(buffer + USBTMC_HEADER_SIZE + this_part, 0, n_bytes - (USBTMC_HEADER_SIZE + this_part));
831 
832 		do {
833 			retval = usb_bulk_msg(data->usb_dev,
834 					      usb_sndbulkpipe(data->usb_dev,
835 							      data->bulk_out),
836 					      buffer, n_bytes,
837 					      &actual, USBTMC_TIMEOUT);
838 			if (retval != 0)
839 				break;
840 			n_bytes -= actual;
841 		} while (n_bytes);
842 
843 		data->bTag_last_write = data->bTag;
844 		data->bTag++;
845 
846 		if (!data->bTag)
847 			data->bTag++;
848 
849 		if (retval < 0) {
850 			dev_err(&data->intf->dev,
851 				"Unable to send data, error %d\n", retval);
852 			if (data->auto_abort)
853 				usbtmc_ioctl_abort_bulk_out(data);
854 			goto exit;
855 		}
856 
857 		remaining -= this_part;
858 		done += this_part;
859 	}
860 
861 	retval = count;
862 exit:
863 	mutex_unlock(&data->io_mutex);
864 	kfree(buffer);
865 	return retval;
866 }
867 
868 static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
869 {
870 	struct usb_host_interface *current_setting;
871 	struct usb_endpoint_descriptor *desc;
872 	struct device *dev;
873 	u8 *buffer;
874 	int rv;
875 	int n;
876 	int actual = 0;
877 	int max_size;
878 
879 	dev = &data->intf->dev;
880 
881 	dev_dbg(dev, "Sending INITIATE_CLEAR request\n");
882 
883 	buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
884 	if (!buffer)
885 		return -ENOMEM;
886 
887 	rv = usb_control_msg(data->usb_dev,
888 			     usb_rcvctrlpipe(data->usb_dev, 0),
889 			     USBTMC_REQUEST_INITIATE_CLEAR,
890 			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
891 			     0, 0, buffer, 1, USBTMC_TIMEOUT);
892 	if (rv < 0) {
893 		dev_err(dev, "usb_control_msg returned %d\n", rv);
894 		goto exit;
895 	}
896 
897 	dev_dbg(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
898 
899 	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
900 		dev_err(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
901 		rv = -EPERM;
902 		goto exit;
903 	}
904 
905 	max_size = 0;
906 	current_setting = data->intf->cur_altsetting;
907 	for (n = 0; n < current_setting->desc.bNumEndpoints; n++) {
908 		desc = &current_setting->endpoint[n].desc;
909 		if (desc->bEndpointAddress == data->bulk_in)
910 			max_size = usb_endpoint_maxp(desc);
911 	}
912 
913 	if (max_size == 0) {
914 		dev_err(dev, "Couldn't get wMaxPacketSize\n");
915 		rv = -EPERM;
916 		goto exit;
917 	}
918 
919 	dev_dbg(dev, "wMaxPacketSize is %d\n", max_size);
920 
921 	n = 0;
922 
923 usbtmc_clear_check_status:
924 
925 	dev_dbg(dev, "Sending CHECK_CLEAR_STATUS request\n");
926 
927 	rv = usb_control_msg(data->usb_dev,
928 			     usb_rcvctrlpipe(data->usb_dev, 0),
929 			     USBTMC_REQUEST_CHECK_CLEAR_STATUS,
930 			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
931 			     0, 0, buffer, 2, USBTMC_TIMEOUT);
932 	if (rv < 0) {
933 		dev_err(dev, "usb_control_msg returned %d\n", rv);
934 		goto exit;
935 	}
936 
937 	dev_dbg(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
938 
939 	if (buffer[0] == USBTMC_STATUS_SUCCESS)
940 		goto usbtmc_clear_bulk_out_halt;
941 
942 	if (buffer[0] != USBTMC_STATUS_PENDING) {
943 		dev_err(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
944 		rv = -EPERM;
945 		goto exit;
946 	}
947 
948 	if (buffer[1] == 1)
949 		do {
950 			dev_dbg(dev, "Reading from bulk in EP\n");
951 
952 			rv = usb_bulk_msg(data->usb_dev,
953 					  usb_rcvbulkpipe(data->usb_dev,
954 							  data->bulk_in),
955 					  buffer, USBTMC_SIZE_IOBUFFER,
956 					  &actual, USBTMC_TIMEOUT);
957 			n++;
958 
959 			if (rv < 0) {
960 				dev_err(dev, "usb_control_msg returned %d\n",
961 					rv);
962 				goto exit;
963 			}
964 		} while ((actual == max_size) &&
965 			  (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
966 
967 	if (actual == max_size) {
968 		dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
969 			USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
970 		rv = -EPERM;
971 		goto exit;
972 	}
973 
974 	goto usbtmc_clear_check_status;
975 
976 usbtmc_clear_bulk_out_halt:
977 
978 	rv = usb_clear_halt(data->usb_dev,
979 			    usb_sndbulkpipe(data->usb_dev, data->bulk_out));
980 	if (rv < 0) {
981 		dev_err(dev, "usb_control_msg returned %d\n", rv);
982 		goto exit;
983 	}
984 	rv = 0;
985 
986 exit:
987 	kfree(buffer);
988 	return rv;
989 }
990 
991 static int usbtmc_ioctl_clear_out_halt(struct usbtmc_device_data *data)
992 {
993 	int rv;
994 
995 	rv = usb_clear_halt(data->usb_dev,
996 			    usb_sndbulkpipe(data->usb_dev, data->bulk_out));
997 
998 	if (rv < 0) {
999 		dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
1000 			rv);
1001 		return rv;
1002 	}
1003 	return 0;
1004 }
1005 
1006 static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data)
1007 {
1008 	int rv;
1009 
1010 	rv = usb_clear_halt(data->usb_dev,
1011 			    usb_rcvbulkpipe(data->usb_dev, data->bulk_in));
1012 
1013 	if (rv < 0) {
1014 		dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
1015 			rv);
1016 		return rv;
1017 	}
1018 	return 0;
1019 }
1020 
1021 static int get_capabilities(struct usbtmc_device_data *data)
1022 {
1023 	struct device *dev = &data->usb_dev->dev;
1024 	char *buffer;
1025 	int rv = 0;
1026 
1027 	buffer = kmalloc(0x18, GFP_KERNEL);
1028 	if (!buffer)
1029 		return -ENOMEM;
1030 
1031 	rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0),
1032 			     USBTMC_REQUEST_GET_CAPABILITIES,
1033 			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1034 			     0, 0, buffer, 0x18, USBTMC_TIMEOUT);
1035 	if (rv < 0) {
1036 		dev_err(dev, "usb_control_msg returned %d\n", rv);
1037 		goto err_out;
1038 	}
1039 
1040 	dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
1041 	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
1042 		dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
1043 		rv = -EPERM;
1044 		goto err_out;
1045 	}
1046 	dev_dbg(dev, "Interface capabilities are %x\n", buffer[4]);
1047 	dev_dbg(dev, "Device capabilities are %x\n", buffer[5]);
1048 	dev_dbg(dev, "USB488 interface capabilities are %x\n", buffer[14]);
1049 	dev_dbg(dev, "USB488 device capabilities are %x\n", buffer[15]);
1050 
1051 	data->capabilities.interface_capabilities = buffer[4];
1052 	data->capabilities.device_capabilities = buffer[5];
1053 	data->capabilities.usb488_interface_capabilities = buffer[14];
1054 	data->capabilities.usb488_device_capabilities = buffer[15];
1055 	data->usb488_caps = (buffer[14] & 0x07) | ((buffer[15] & 0x0f) << 4);
1056 	rv = 0;
1057 
1058 err_out:
1059 	kfree(buffer);
1060 	return rv;
1061 }
1062 
1063 #define capability_attribute(name)					\
1064 static ssize_t name##_show(struct device *dev,				\
1065 			   struct device_attribute *attr, char *buf)	\
1066 {									\
1067 	struct usb_interface *intf = to_usb_interface(dev);		\
1068 	struct usbtmc_device_data *data = usb_get_intfdata(intf);	\
1069 									\
1070 	return sprintf(buf, "%d\n", data->capabilities.name);		\
1071 }									\
1072 static DEVICE_ATTR_RO(name)
1073 
1074 capability_attribute(interface_capabilities);
1075 capability_attribute(device_capabilities);
1076 capability_attribute(usb488_interface_capabilities);
1077 capability_attribute(usb488_device_capabilities);
1078 
1079 static struct attribute *capability_attrs[] = {
1080 	&dev_attr_interface_capabilities.attr,
1081 	&dev_attr_device_capabilities.attr,
1082 	&dev_attr_usb488_interface_capabilities.attr,
1083 	&dev_attr_usb488_device_capabilities.attr,
1084 	NULL,
1085 };
1086 
1087 static struct attribute_group capability_attr_grp = {
1088 	.attrs = capability_attrs,
1089 };
1090 
1091 static ssize_t TermChar_show(struct device *dev,
1092 			     struct device_attribute *attr, char *buf)
1093 {
1094 	struct usb_interface *intf = to_usb_interface(dev);
1095 	struct usbtmc_device_data *data = usb_get_intfdata(intf);
1096 
1097 	return sprintf(buf, "%c\n", data->TermChar);
1098 }
1099 
1100 static ssize_t TermChar_store(struct device *dev,
1101 			      struct device_attribute *attr,
1102 			      const char *buf, size_t count)
1103 {
1104 	struct usb_interface *intf = to_usb_interface(dev);
1105 	struct usbtmc_device_data *data = usb_get_intfdata(intf);
1106 
1107 	if (count < 1)
1108 		return -EINVAL;
1109 	data->TermChar = buf[0];
1110 	return count;
1111 }
1112 static DEVICE_ATTR_RW(TermChar);
1113 
1114 #define data_attribute(name)						\
1115 static ssize_t name##_show(struct device *dev,				\
1116 			   struct device_attribute *attr, char *buf)	\
1117 {									\
1118 	struct usb_interface *intf = to_usb_interface(dev);		\
1119 	struct usbtmc_device_data *data = usb_get_intfdata(intf);	\
1120 									\
1121 	return sprintf(buf, "%d\n", data->name);			\
1122 }									\
1123 static ssize_t name##_store(struct device *dev,				\
1124 			    struct device_attribute *attr,		\
1125 			    const char *buf, size_t count)		\
1126 {									\
1127 	struct usb_interface *intf = to_usb_interface(dev);		\
1128 	struct usbtmc_device_data *data = usb_get_intfdata(intf);	\
1129 	ssize_t result;							\
1130 	unsigned val;							\
1131 									\
1132 	result = sscanf(buf, "%u\n", &val);				\
1133 	if (result != 1)						\
1134 		result = -EINVAL;					\
1135 	data->name = val;						\
1136 	if (result < 0)							\
1137 		return result;						\
1138 	else								\
1139 		return count;						\
1140 }									\
1141 static DEVICE_ATTR_RW(name)
1142 
1143 data_attribute(TermCharEnabled);
1144 data_attribute(auto_abort);
1145 
1146 static struct attribute *data_attrs[] = {
1147 	&dev_attr_TermChar.attr,
1148 	&dev_attr_TermCharEnabled.attr,
1149 	&dev_attr_auto_abort.attr,
1150 	NULL,
1151 };
1152 
1153 static struct attribute_group data_attr_grp = {
1154 	.attrs = data_attrs,
1155 };
1156 
1157 static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
1158 {
1159 	struct device *dev;
1160 	u8 *buffer;
1161 	int rv;
1162 
1163 	dev = &data->intf->dev;
1164 
1165 	buffer = kmalloc(2, GFP_KERNEL);
1166 	if (!buffer)
1167 		return -ENOMEM;
1168 
1169 	rv = usb_control_msg(data->usb_dev,
1170 			     usb_rcvctrlpipe(data->usb_dev, 0),
1171 			     USBTMC_REQUEST_INDICATOR_PULSE,
1172 			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1173 			     0, 0, buffer, 0x01, USBTMC_TIMEOUT);
1174 
1175 	if (rv < 0) {
1176 		dev_err(dev, "usb_control_msg returned %d\n", rv);
1177 		goto exit;
1178 	}
1179 
1180 	dev_dbg(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
1181 
1182 	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
1183 		dev_err(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
1184 		rv = -EPERM;
1185 		goto exit;
1186 	}
1187 	rv = 0;
1188 
1189 exit:
1190 	kfree(buffer);
1191 	return rv;
1192 }
1193 
1194 static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1195 {
1196 	struct usbtmc_device_data *data;
1197 	int retval = -EBADRQC;
1198 
1199 	data = file->private_data;
1200 	mutex_lock(&data->io_mutex);
1201 	if (data->zombie) {
1202 		retval = -ENODEV;
1203 		goto skip_io_on_zombie;
1204 	}
1205 
1206 	switch (cmd) {
1207 	case USBTMC_IOCTL_CLEAR_OUT_HALT:
1208 		retval = usbtmc_ioctl_clear_out_halt(data);
1209 		break;
1210 
1211 	case USBTMC_IOCTL_CLEAR_IN_HALT:
1212 		retval = usbtmc_ioctl_clear_in_halt(data);
1213 		break;
1214 
1215 	case USBTMC_IOCTL_INDICATOR_PULSE:
1216 		retval = usbtmc_ioctl_indicator_pulse(data);
1217 		break;
1218 
1219 	case USBTMC_IOCTL_CLEAR:
1220 		retval = usbtmc_ioctl_clear(data);
1221 		break;
1222 
1223 	case USBTMC_IOCTL_ABORT_BULK_OUT:
1224 		retval = usbtmc_ioctl_abort_bulk_out(data);
1225 		break;
1226 
1227 	case USBTMC_IOCTL_ABORT_BULK_IN:
1228 		retval = usbtmc_ioctl_abort_bulk_in(data);
1229 		break;
1230 
1231 	case USBTMC488_IOCTL_GET_CAPS:
1232 		retval = copy_to_user((void __user *)arg,
1233 				&data->usb488_caps,
1234 				sizeof(data->usb488_caps));
1235 		if (retval)
1236 			retval = -EFAULT;
1237 		break;
1238 
1239 	case USBTMC488_IOCTL_READ_STB:
1240 		retval = usbtmc488_ioctl_read_stb(data, (void __user *)arg);
1241 		break;
1242 
1243 	case USBTMC488_IOCTL_REN_CONTROL:
1244 		retval = usbtmc488_ioctl_simple(data, (void __user *)arg,
1245 						USBTMC488_REQUEST_REN_CONTROL);
1246 		break;
1247 
1248 	case USBTMC488_IOCTL_GOTO_LOCAL:
1249 		retval = usbtmc488_ioctl_simple(data, (void __user *)arg,
1250 						USBTMC488_REQUEST_GOTO_LOCAL);
1251 		break;
1252 
1253 	case USBTMC488_IOCTL_LOCAL_LOCKOUT:
1254 		retval = usbtmc488_ioctl_simple(data, (void __user *)arg,
1255 						USBTMC488_REQUEST_LOCAL_LOCKOUT);
1256 		break;
1257 	}
1258 
1259 skip_io_on_zombie:
1260 	mutex_unlock(&data->io_mutex);
1261 	return retval;
1262 }
1263 
1264 static int usbtmc_fasync(int fd, struct file *file, int on)
1265 {
1266 	struct usbtmc_device_data *data = file->private_data;
1267 
1268 	return fasync_helper(fd, file, on, &data->fasync);
1269 }
1270 
1271 static unsigned int usbtmc_poll(struct file *file, poll_table *wait)
1272 {
1273 	struct usbtmc_device_data *data = file->private_data;
1274 	unsigned int mask;
1275 
1276 	mutex_lock(&data->io_mutex);
1277 
1278 	if (data->zombie) {
1279 		mask = POLLHUP | POLLERR;
1280 		goto no_poll;
1281 	}
1282 
1283 	poll_wait(file, &data->waitq, wait);
1284 
1285 	mask = (atomic_read(&data->srq_asserted)) ? POLLIN | POLLRDNORM : 0;
1286 
1287 no_poll:
1288 	mutex_unlock(&data->io_mutex);
1289 	return mask;
1290 }
1291 
1292 static const struct file_operations fops = {
1293 	.owner		= THIS_MODULE,
1294 	.read		= usbtmc_read,
1295 	.write		= usbtmc_write,
1296 	.open		= usbtmc_open,
1297 	.release	= usbtmc_release,
1298 	.unlocked_ioctl	= usbtmc_ioctl,
1299 	.fasync         = usbtmc_fasync,
1300 	.poll           = usbtmc_poll,
1301 	.llseek		= default_llseek,
1302 };
1303 
1304 static struct usb_class_driver usbtmc_class = {
1305 	.name =		"usbtmc%d",
1306 	.fops =		&fops,
1307 	.minor_base =	USBTMC_MINOR_BASE,
1308 };
1309 
1310 static void usbtmc_interrupt(struct urb *urb)
1311 {
1312 	struct usbtmc_device_data *data = urb->context;
1313 	struct device *dev = &data->intf->dev;
1314 	int status = urb->status;
1315 	int rv;
1316 
1317 	dev_dbg(&data->intf->dev, "int status: %d len %d\n",
1318 		status, urb->actual_length);
1319 
1320 	switch (status) {
1321 	case 0: /* SUCCESS */
1322 		/* check for valid STB notification */
1323 		if (data->iin_buffer[0] > 0x81) {
1324 			data->bNotify1 = data->iin_buffer[0];
1325 			data->bNotify2 = data->iin_buffer[1];
1326 			atomic_set(&data->iin_data_valid, 1);
1327 			wake_up_interruptible(&data->waitq);
1328 			goto exit;
1329 		}
1330 		/* check for SRQ notification */
1331 		if (data->iin_buffer[0] == 0x81) {
1332 			if (data->fasync)
1333 				kill_fasync(&data->fasync,
1334 					SIGIO, POLL_IN);
1335 
1336 			atomic_set(&data->srq_asserted, 1);
1337 			wake_up_interruptible(&data->waitq);
1338 			goto exit;
1339 		}
1340 		dev_warn(dev, "invalid notification: %x\n", data->iin_buffer[0]);
1341 		break;
1342 	case -EOVERFLOW:
1343 		dev_err(dev, "overflow with length %d, actual length is %d\n",
1344 			data->iin_wMaxPacketSize, urb->actual_length);
1345 	case -ECONNRESET:
1346 	case -ENOENT:
1347 	case -ESHUTDOWN:
1348 	case -EILSEQ:
1349 	case -ETIME:
1350 		/* urb terminated, clean up */
1351 		dev_dbg(dev, "urb terminated, status: %d\n", status);
1352 		return;
1353 	default:
1354 		dev_err(dev, "unknown status received: %d\n", status);
1355 	}
1356 exit:
1357 	rv = usb_submit_urb(urb, GFP_ATOMIC);
1358 	if (rv)
1359 		dev_err(dev, "usb_submit_urb failed: %d\n", rv);
1360 }
1361 
1362 static void usbtmc_free_int(struct usbtmc_device_data *data)
1363 {
1364 	if (!data->iin_ep_present || !data->iin_urb)
1365 		return;
1366 	usb_kill_urb(data->iin_urb);
1367 	kfree(data->iin_buffer);
1368 	usb_free_urb(data->iin_urb);
1369 	kref_put(&data->kref, usbtmc_delete);
1370 }
1371 
1372 static int usbtmc_probe(struct usb_interface *intf,
1373 			const struct usb_device_id *id)
1374 {
1375 	struct usbtmc_device_data *data;
1376 	struct usb_host_interface *iface_desc;
1377 	struct usb_endpoint_descriptor *endpoint;
1378 	int n;
1379 	int retcode;
1380 
1381 	dev_dbg(&intf->dev, "%s called\n", __func__);
1382 
1383 	data = kmalloc(sizeof(*data), GFP_KERNEL);
1384 	if (!data)
1385 		return -ENOMEM;
1386 
1387 	data->intf = intf;
1388 	data->id = id;
1389 	data->usb_dev = usb_get_dev(interface_to_usbdev(intf));
1390 	usb_set_intfdata(intf, data);
1391 	kref_init(&data->kref);
1392 	mutex_init(&data->io_mutex);
1393 	init_waitqueue_head(&data->waitq);
1394 	atomic_set(&data->iin_data_valid, 0);
1395 	atomic_set(&data->srq_asserted, 0);
1396 	data->zombie = 0;
1397 
1398 	/* Determine if it is a Rigol or not */
1399 	data->rigol_quirk = 0;
1400 	dev_dbg(&intf->dev, "Trying to find if device Vendor 0x%04X Product 0x%04X has the RIGOL quirk\n",
1401 		le16_to_cpu(data->usb_dev->descriptor.idVendor),
1402 		le16_to_cpu(data->usb_dev->descriptor.idProduct));
1403 	for(n = 0; usbtmc_id_quirk[n].idVendor > 0; n++) {
1404 		if ((usbtmc_id_quirk[n].idVendor == le16_to_cpu(data->usb_dev->descriptor.idVendor)) &&
1405 		    (usbtmc_id_quirk[n].idProduct == le16_to_cpu(data->usb_dev->descriptor.idProduct))) {
1406 			dev_dbg(&intf->dev, "Setting this device as having the RIGOL quirk\n");
1407 			data->rigol_quirk = 1;
1408 			break;
1409 		}
1410 	}
1411 
1412 	/* Initialize USBTMC bTag and other fields */
1413 	data->bTag	= 1;
1414 	data->TermCharEnabled = 0;
1415 	data->TermChar = '\n';
1416 	/*  2 <= bTag <= 127   USBTMC-USB488 subclass specification 4.3.1 */
1417 	data->iin_bTag = 2;
1418 
1419 	/* USBTMC devices have only one setting, so use that */
1420 	iface_desc = data->intf->cur_altsetting;
1421 	data->ifnum = iface_desc->desc.bInterfaceNumber;
1422 
1423 	/* Find bulk in endpoint */
1424 	for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1425 		endpoint = &iface_desc->endpoint[n].desc;
1426 
1427 		if (usb_endpoint_is_bulk_in(endpoint)) {
1428 			data->bulk_in = endpoint->bEndpointAddress;
1429 			dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n",
1430 				data->bulk_in);
1431 			break;
1432 		}
1433 	}
1434 
1435 	/* Find bulk out endpoint */
1436 	for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1437 		endpoint = &iface_desc->endpoint[n].desc;
1438 
1439 		if (usb_endpoint_is_bulk_out(endpoint)) {
1440 			data->bulk_out = endpoint->bEndpointAddress;
1441 			dev_dbg(&intf->dev, "Found Bulk out endpoint at %u\n",
1442 				data->bulk_out);
1443 			break;
1444 		}
1445 	}
1446 	/* Find int endpoint */
1447 	for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1448 		endpoint = &iface_desc->endpoint[n].desc;
1449 
1450 		if (usb_endpoint_is_int_in(endpoint)) {
1451 			data->iin_ep_present = 1;
1452 			data->iin_ep = endpoint->bEndpointAddress;
1453 			data->iin_wMaxPacketSize = usb_endpoint_maxp(endpoint);
1454 			data->iin_interval = endpoint->bInterval;
1455 			dev_dbg(&intf->dev, "Found Int in endpoint at %u\n",
1456 				data->iin_ep);
1457 			break;
1458 		}
1459 	}
1460 
1461 	retcode = get_capabilities(data);
1462 	if (retcode)
1463 		dev_err(&intf->dev, "can't read capabilities\n");
1464 	else
1465 		retcode = sysfs_create_group(&intf->dev.kobj,
1466 					     &capability_attr_grp);
1467 
1468 	if (data->iin_ep_present) {
1469 		/* allocate int urb */
1470 		data->iin_urb = usb_alloc_urb(0, GFP_KERNEL);
1471 		if (!data->iin_urb)
1472 			goto error_register;
1473 
1474 		/* will reference data in int urb */
1475 		kref_get(&data->kref);
1476 
1477 		/* allocate buffer for interrupt in */
1478 		data->iin_buffer = kmalloc(data->iin_wMaxPacketSize,
1479 					GFP_KERNEL);
1480 		if (!data->iin_buffer)
1481 			goto error_register;
1482 
1483 		/* fill interrupt urb */
1484 		usb_fill_int_urb(data->iin_urb, data->usb_dev,
1485 				usb_rcvintpipe(data->usb_dev, data->iin_ep),
1486 				data->iin_buffer, data->iin_wMaxPacketSize,
1487 				usbtmc_interrupt,
1488 				data, data->iin_interval);
1489 
1490 		retcode = usb_submit_urb(data->iin_urb, GFP_KERNEL);
1491 		if (retcode) {
1492 			dev_err(&intf->dev, "Failed to submit iin_urb\n");
1493 			goto error_register;
1494 		}
1495 	}
1496 
1497 	retcode = sysfs_create_group(&intf->dev.kobj, &data_attr_grp);
1498 
1499 	retcode = usb_register_dev(intf, &usbtmc_class);
1500 	if (retcode) {
1501 		dev_err(&intf->dev, "Not able to get a minor"
1502 			" (base %u, slice default): %d\n", USBTMC_MINOR_BASE,
1503 			retcode);
1504 		goto error_register;
1505 	}
1506 	dev_dbg(&intf->dev, "Using minor number %d\n", intf->minor);
1507 
1508 	return 0;
1509 
1510 error_register:
1511 	sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1512 	sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1513 	usbtmc_free_int(data);
1514 	kref_put(&data->kref, usbtmc_delete);
1515 	return retcode;
1516 }
1517 
1518 static void usbtmc_disconnect(struct usb_interface *intf)
1519 {
1520 	struct usbtmc_device_data *data;
1521 
1522 	dev_dbg(&intf->dev, "usbtmc_disconnect called\n");
1523 
1524 	data = usb_get_intfdata(intf);
1525 	usb_deregister_dev(intf, &usbtmc_class);
1526 	sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1527 	sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1528 	mutex_lock(&data->io_mutex);
1529 	data->zombie = 1;
1530 	wake_up_all(&data->waitq);
1531 	mutex_unlock(&data->io_mutex);
1532 	usbtmc_free_int(data);
1533 	kref_put(&data->kref, usbtmc_delete);
1534 }
1535 
1536 static int usbtmc_suspend(struct usb_interface *intf, pm_message_t message)
1537 {
1538 	/* this driver does not have pending URBs */
1539 	return 0;
1540 }
1541 
1542 static int usbtmc_resume(struct usb_interface *intf)
1543 {
1544 	return 0;
1545 }
1546 
1547 static struct usb_driver usbtmc_driver = {
1548 	.name		= "usbtmc",
1549 	.id_table	= usbtmc_devices,
1550 	.probe		= usbtmc_probe,
1551 	.disconnect	= usbtmc_disconnect,
1552 	.suspend	= usbtmc_suspend,
1553 	.resume		= usbtmc_resume,
1554 };
1555 
1556 module_usb_driver(usbtmc_driver);
1557 
1558 MODULE_LICENSE("GPL");
1559