• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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/mutex.h>
31 #include <linux/usb.h>
32 #include <linux/usb/tmc.h>
33 
34 
35 #define RIGOL			1
36 #define USBTMC_HEADER_SIZE	12
37 #define USBTMC_MINOR_BASE	176
38 
39 /*
40  * Size of driver internal IO buffer. Must be multiple of 4 and at least as
41  * large as wMaxPacketSize (which is usually 512 bytes).
42  */
43 #define USBTMC_SIZE_IOBUFFER	2048
44 
45 /* Default USB timeout (in milliseconds) */
46 #define USBTMC_TIMEOUT		5000
47 
48 /*
49  * Maximum number of read cycles to empty bulk in endpoint during CLEAR and
50  * ABORT_BULK_IN requests. Ends the loop if (for whatever reason) a short
51  * packet is never read.
52  */
53 #define USBTMC_MAX_READS_TO_CLEAR_BULK_IN	100
54 
55 static const struct usb_device_id usbtmc_devices[] = {
56 	{ USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 0), },
57 	{ USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 1), },
58 	{ 0, } /* terminating entry */
59 };
60 MODULE_DEVICE_TABLE(usb, usbtmc_devices);
61 
62 /*
63  * This structure is the capabilities for the device
64  * See section 4.2.1.8 of the USBTMC specification,
65  * and section 4.2.2 of the USBTMC usb488 subclass
66  * specification for details.
67  */
68 struct usbtmc_dev_capabilities {
69 	__u8 interface_capabilities;
70 	__u8 device_capabilities;
71 	__u8 usb488_interface_capabilities;
72 	__u8 usb488_device_capabilities;
73 };
74 
75 /* This structure holds private data for each USBTMC device. One copy is
76  * allocated for each USBTMC device in the driver's probe function.
77  */
78 struct usbtmc_device_data {
79 	const struct usb_device_id *id;
80 	struct usb_device *usb_dev;
81 	struct usb_interface *intf;
82 
83 	unsigned int bulk_in;
84 	unsigned int bulk_out;
85 
86 	u8 bTag;
87 	u8 bTag_last_write;	/* needed for abort */
88 	u8 bTag_last_read;	/* needed for abort */
89 
90 	u8 rigol_quirk;
91 
92 	/* attributes from the USB TMC spec for this device */
93 	u8 TermChar;
94 	bool TermCharEnabled;
95 	bool auto_abort;
96 
97 	bool zombie; /* fd of disconnected device */
98 
99 	struct usbtmc_dev_capabilities	capabilities;
100 	struct kref kref;
101 	struct mutex io_mutex;	/* only one i/o function running at a time */
102 };
103 #define to_usbtmc_data(d) container_of(d, struct usbtmc_device_data, kref)
104 
105 struct usbtmc_ID_rigol_quirk {
106 	__u16 idVendor;
107 	__u16 idProduct;
108 };
109 
110 static const struct usbtmc_ID_rigol_quirk usbtmc_id_quirk[] = {
111 	{ 0x1ab1, 0x0588 },
112 	{ 0x1ab1, 0x04b0 },
113 	{ 0, 0 }
114 };
115 
116 /* Forward declarations */
117 static struct usb_driver usbtmc_driver;
118 
usbtmc_delete(struct kref * kref)119 static void usbtmc_delete(struct kref *kref)
120 {
121 	struct usbtmc_device_data *data = to_usbtmc_data(kref);
122 
123 	usb_put_dev(data->usb_dev);
124 	kfree(data);
125 }
126 
usbtmc_open(struct inode * inode,struct file * filp)127 static int usbtmc_open(struct inode *inode, struct file *filp)
128 {
129 	struct usb_interface *intf;
130 	struct usbtmc_device_data *data;
131 	int retval = 0;
132 
133 	intf = usb_find_interface(&usbtmc_driver, iminor(inode));
134 	if (!intf) {
135 		pr_err("can not find device for minor %d", iminor(inode));
136 		return -ENODEV;
137 	}
138 
139 	data = usb_get_intfdata(intf);
140 	kref_get(&data->kref);
141 
142 	/* Store pointer in file structure's private data field */
143 	filp->private_data = data;
144 
145 	return retval;
146 }
147 
usbtmc_release(struct inode * inode,struct file * file)148 static int usbtmc_release(struct inode *inode, struct file *file)
149 {
150 	struct usbtmc_device_data *data = file->private_data;
151 
152 	kref_put(&data->kref, usbtmc_delete);
153 	return 0;
154 }
155 
usbtmc_ioctl_abort_bulk_in(struct usbtmc_device_data * data)156 static int usbtmc_ioctl_abort_bulk_in(struct usbtmc_device_data *data)
157 {
158 	u8 *buffer;
159 	struct device *dev;
160 	int rv;
161 	int n;
162 	int actual;
163 	struct usb_host_interface *current_setting;
164 	int max_size;
165 
166 	dev = &data->intf->dev;
167 	buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
168 	if (!buffer)
169 		return -ENOMEM;
170 
171 	rv = usb_control_msg(data->usb_dev,
172 			     usb_rcvctrlpipe(data->usb_dev, 0),
173 			     USBTMC_REQUEST_INITIATE_ABORT_BULK_IN,
174 			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
175 			     data->bTag_last_read, data->bulk_in,
176 			     buffer, 2, USBTMC_TIMEOUT);
177 
178 	if (rv < 0) {
179 		dev_err(dev, "usb_control_msg returned %d\n", rv);
180 		goto exit;
181 	}
182 
183 	dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
184 
185 	if (buffer[0] == USBTMC_STATUS_FAILED) {
186 		rv = 0;
187 		goto exit;
188 	}
189 
190 	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
191 		dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n",
192 			buffer[0]);
193 		rv = -EPERM;
194 		goto exit;
195 	}
196 
197 	max_size = 0;
198 	current_setting = data->intf->cur_altsetting;
199 	for (n = 0; n < current_setting->desc.bNumEndpoints; n++)
200 		if (current_setting->endpoint[n].desc.bEndpointAddress ==
201 			data->bulk_in)
202 			max_size = usb_endpoint_maxp(&current_setting->endpoint[n].desc);
203 
204 	if (max_size == 0) {
205 		dev_err(dev, "Couldn't get wMaxPacketSize\n");
206 		rv = -EPERM;
207 		goto exit;
208 	}
209 
210 	dev_dbg(&data->intf->dev, "wMaxPacketSize is %d\n", max_size);
211 
212 	n = 0;
213 
214 	do {
215 		dev_dbg(dev, "Reading from bulk in EP\n");
216 
217 		rv = usb_bulk_msg(data->usb_dev,
218 				  usb_rcvbulkpipe(data->usb_dev,
219 						  data->bulk_in),
220 				  buffer, USBTMC_SIZE_IOBUFFER,
221 				  &actual, USBTMC_TIMEOUT);
222 
223 		n++;
224 
225 		if (rv < 0) {
226 			dev_err(dev, "usb_bulk_msg returned %d\n", rv);
227 			goto exit;
228 		}
229 	} while ((actual == max_size) &&
230 		 (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
231 
232 	if (actual == max_size) {
233 		dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
234 			USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
235 		rv = -EPERM;
236 		goto exit;
237 	}
238 
239 	n = 0;
240 
241 usbtmc_abort_bulk_in_status:
242 	rv = usb_control_msg(data->usb_dev,
243 			     usb_rcvctrlpipe(data->usb_dev, 0),
244 			     USBTMC_REQUEST_CHECK_ABORT_BULK_IN_STATUS,
245 			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
246 			     0, data->bulk_in, buffer, 0x08,
247 			     USBTMC_TIMEOUT);
248 
249 	if (rv < 0) {
250 		dev_err(dev, "usb_control_msg returned %d\n", rv);
251 		goto exit;
252 	}
253 
254 	dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
255 
256 	if (buffer[0] == USBTMC_STATUS_SUCCESS) {
257 		rv = 0;
258 		goto exit;
259 	}
260 
261 	if (buffer[0] != USBTMC_STATUS_PENDING) {
262 		dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
263 		rv = -EPERM;
264 		goto exit;
265 	}
266 
267 	if (buffer[1] == 1)
268 		do {
269 			dev_dbg(dev, "Reading from bulk in EP\n");
270 
271 			rv = usb_bulk_msg(data->usb_dev,
272 					  usb_rcvbulkpipe(data->usb_dev,
273 							  data->bulk_in),
274 					  buffer, USBTMC_SIZE_IOBUFFER,
275 					  &actual, USBTMC_TIMEOUT);
276 
277 			n++;
278 
279 			if (rv < 0) {
280 				dev_err(dev, "usb_bulk_msg returned %d\n", rv);
281 				goto exit;
282 			}
283 		} while ((actual == max_size) &&
284 			 (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
285 
286 	if (actual == max_size) {
287 		dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
288 			USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
289 		rv = -EPERM;
290 		goto exit;
291 	}
292 
293 	goto usbtmc_abort_bulk_in_status;
294 
295 exit:
296 	kfree(buffer);
297 	return rv;
298 
299 }
300 
usbtmc_ioctl_abort_bulk_out(struct usbtmc_device_data * data)301 static int usbtmc_ioctl_abort_bulk_out(struct usbtmc_device_data *data)
302 {
303 	struct device *dev;
304 	u8 *buffer;
305 	int rv;
306 	int n;
307 
308 	dev = &data->intf->dev;
309 
310 	buffer = kmalloc(8, GFP_KERNEL);
311 	if (!buffer)
312 		return -ENOMEM;
313 
314 	rv = usb_control_msg(data->usb_dev,
315 			     usb_rcvctrlpipe(data->usb_dev, 0),
316 			     USBTMC_REQUEST_INITIATE_ABORT_BULK_OUT,
317 			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
318 			     data->bTag_last_write, data->bulk_out,
319 			     buffer, 2, USBTMC_TIMEOUT);
320 
321 	if (rv < 0) {
322 		dev_err(dev, "usb_control_msg returned %d\n", rv);
323 		goto exit;
324 	}
325 
326 	dev_dbg(dev, "INITIATE_ABORT_BULK_OUT returned %x\n", buffer[0]);
327 
328 	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
329 		dev_err(dev, "INITIATE_ABORT_BULK_OUT returned %x\n",
330 			buffer[0]);
331 		rv = -EPERM;
332 		goto exit;
333 	}
334 
335 	n = 0;
336 
337 usbtmc_abort_bulk_out_check_status:
338 	rv = usb_control_msg(data->usb_dev,
339 			     usb_rcvctrlpipe(data->usb_dev, 0),
340 			     USBTMC_REQUEST_CHECK_ABORT_BULK_OUT_STATUS,
341 			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
342 			     0, data->bulk_out, buffer, 0x08,
343 			     USBTMC_TIMEOUT);
344 	n++;
345 	if (rv < 0) {
346 		dev_err(dev, "usb_control_msg returned %d\n", rv);
347 		goto exit;
348 	}
349 
350 	dev_dbg(dev, "CHECK_ABORT_BULK_OUT returned %x\n", buffer[0]);
351 
352 	if (buffer[0] == USBTMC_STATUS_SUCCESS)
353 		goto usbtmc_abort_bulk_out_clear_halt;
354 
355 	if ((buffer[0] == USBTMC_STATUS_PENDING) &&
356 	    (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN))
357 		goto usbtmc_abort_bulk_out_check_status;
358 
359 	rv = -EPERM;
360 	goto exit;
361 
362 usbtmc_abort_bulk_out_clear_halt:
363 	rv = usb_clear_halt(data->usb_dev,
364 			    usb_sndbulkpipe(data->usb_dev, data->bulk_out));
365 
366 	if (rv < 0) {
367 		dev_err(dev, "usb_control_msg returned %d\n", rv);
368 		goto exit;
369 	}
370 	rv = 0;
371 
372 exit:
373 	kfree(buffer);
374 	return rv;
375 }
376 
377 /*
378  * Sends a REQUEST_DEV_DEP_MSG_IN message on the Bulk-IN endpoint.
379  * @transfer_size: number of bytes to request from the device.
380  *
381  * See the USBTMC specification, Table 4.
382  *
383  * Also updates bTag_last_write.
384  */
send_request_dev_dep_msg_in(struct usbtmc_device_data * data,size_t transfer_size)385 static int send_request_dev_dep_msg_in(struct usbtmc_device_data *data, size_t transfer_size)
386 {
387 	int retval;
388 	u8 *buffer;
389 	int actual;
390 
391 	buffer = kmalloc(USBTMC_HEADER_SIZE, GFP_KERNEL);
392 	if (!buffer)
393 		return -ENOMEM;
394 	/* Setup IO buffer for REQUEST_DEV_DEP_MSG_IN message
395 	 * Refer to class specs for details
396 	 */
397 	buffer[0] = 2;
398 	buffer[1] = data->bTag;
399 	buffer[2] = ~data->bTag;
400 	buffer[3] = 0; /* Reserved */
401 	buffer[4] = transfer_size >> 0;
402 	buffer[5] = transfer_size >> 8;
403 	buffer[6] = transfer_size >> 16;
404 	buffer[7] = transfer_size >> 24;
405 	buffer[8] = data->TermCharEnabled * 2;
406 	/* Use term character? */
407 	buffer[9] = data->TermChar;
408 	buffer[10] = 0; /* Reserved */
409 	buffer[11] = 0; /* Reserved */
410 
411 	/* Send bulk URB */
412 	retval = usb_bulk_msg(data->usb_dev,
413 			      usb_sndbulkpipe(data->usb_dev,
414 					      data->bulk_out),
415 			      buffer, USBTMC_HEADER_SIZE, &actual, USBTMC_TIMEOUT);
416 
417 	/* Store bTag (in case we need to abort) */
418 	data->bTag_last_write = data->bTag;
419 
420 	/* Increment bTag -- and increment again if zero */
421 	data->bTag++;
422 	if (!data->bTag)
423 		data->bTag++;
424 
425 	kfree(buffer);
426 	if (retval < 0) {
427 		dev_err(&data->intf->dev, "usb_bulk_msg in send_request_dev_dep_msg_in() returned %d\n", retval);
428 		return retval;
429 	}
430 
431 	return 0;
432 }
433 
usbtmc_read(struct file * filp,char __user * buf,size_t count,loff_t * f_pos)434 static ssize_t usbtmc_read(struct file *filp, char __user *buf,
435 			   size_t count, loff_t *f_pos)
436 {
437 	struct usbtmc_device_data *data;
438 	struct device *dev;
439 	u32 n_characters;
440 	u8 *buffer;
441 	int actual;
442 	size_t done;
443 	size_t remaining;
444 	int retval;
445 	size_t this_part;
446 
447 	/* Get pointer to private data structure */
448 	data = filp->private_data;
449 	dev = &data->intf->dev;
450 
451 	buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
452 	if (!buffer)
453 		return -ENOMEM;
454 
455 	mutex_lock(&data->io_mutex);
456 	if (data->zombie) {
457 		retval = -ENODEV;
458 		goto exit;
459 	}
460 
461 	if (data->rigol_quirk) {
462 		dev_dbg(dev, "usb_bulk_msg_in: count(%zu)\n", count);
463 
464 		retval = send_request_dev_dep_msg_in(data, count);
465 
466 		if (retval < 0) {
467 			if (data->auto_abort)
468 				usbtmc_ioctl_abort_bulk_out(data);
469 			goto exit;
470 		}
471 	}
472 
473 	/* Loop until we have fetched everything we requested */
474 	remaining = count;
475 	this_part = remaining;
476 	done = 0;
477 
478 	while (remaining > 0) {
479 		if (!data->rigol_quirk) {
480 			dev_dbg(dev, "usb_bulk_msg_in: remaining(%zu), count(%zu)\n", remaining, count);
481 
482 			if (remaining > USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE - 3)
483 				this_part = USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE - 3;
484 			else
485 				this_part = remaining;
486 
487 			retval = send_request_dev_dep_msg_in(data, this_part);
488 			if (retval < 0) {
489 			dev_err(dev, "usb_bulk_msg returned %d\n", retval);
490 				if (data->auto_abort)
491 					usbtmc_ioctl_abort_bulk_out(data);
492 				goto exit;
493 			}
494 		}
495 
496 		/* Send bulk URB */
497 		retval = usb_bulk_msg(data->usb_dev,
498 				      usb_rcvbulkpipe(data->usb_dev,
499 						      data->bulk_in),
500 				      buffer, USBTMC_SIZE_IOBUFFER, &actual,
501 				      USBTMC_TIMEOUT);
502 
503 		dev_dbg(dev, "usb_bulk_msg: retval(%u), done(%zu), remaining(%zu), actual(%d)\n", retval, done, remaining, actual);
504 
505 		/* Store bTag (in case we need to abort) */
506 		data->bTag_last_read = data->bTag;
507 
508 		if (retval < 0) {
509 			dev_dbg(dev, "Unable to read data, error %d\n", retval);
510 			if (data->auto_abort)
511 				usbtmc_ioctl_abort_bulk_in(data);
512 			goto exit;
513 		}
514 
515 		/* Parse header in first packet */
516 		if ((done == 0) || !data->rigol_quirk) {
517 			/* Sanity checks for the header */
518 			if (actual < USBTMC_HEADER_SIZE) {
519 				dev_err(dev, "Device sent too small first packet: %u < %u\n", actual, USBTMC_HEADER_SIZE);
520 				if (data->auto_abort)
521 					usbtmc_ioctl_abort_bulk_in(data);
522 				goto exit;
523 			}
524 
525 			if (buffer[0] != 2) {
526 				dev_err(dev, "Device sent reply with wrong MsgID: %u != 2\n", buffer[0]);
527 				if (data->auto_abort)
528 					usbtmc_ioctl_abort_bulk_in(data);
529 				goto exit;
530 			}
531 
532 			if (buffer[1] != data->bTag_last_write) {
533 				dev_err(dev, "Device sent reply with wrong bTag: %u != %u\n", buffer[1], data->bTag_last_write);
534 				if (data->auto_abort)
535 					usbtmc_ioctl_abort_bulk_in(data);
536 				goto exit;
537 			}
538 
539 			/* How many characters did the instrument send? */
540 			n_characters = buffer[4] +
541 				       (buffer[5] << 8) +
542 				       (buffer[6] << 16) +
543 				       (buffer[7] << 24);
544 
545 			if (n_characters > this_part) {
546 				dev_err(dev, "Device wants to return more data than requested: %u > %zu\n", n_characters, count);
547 				if (data->auto_abort)
548 					usbtmc_ioctl_abort_bulk_in(data);
549 				goto exit;
550 			}
551 
552 			/* Remove the USBTMC header */
553 			actual -= USBTMC_HEADER_SIZE;
554 
555 			/* Check if the message is smaller than requested */
556 			if (data->rigol_quirk) {
557 				if (remaining > n_characters)
558 					remaining = n_characters;
559 				/* Remove padding if it exists */
560 				if (actual > remaining)
561 					actual = remaining;
562 			}
563 			else {
564 				if (this_part > n_characters)
565 					this_part = n_characters;
566 				/* Remove padding if it exists */
567 				if (actual > this_part)
568 					actual = this_part;
569 			}
570 
571 			dev_dbg(dev, "Bulk-IN header: N_characters(%u), bTransAttr(%u)\n", n_characters, buffer[8]);
572 
573 			remaining -= actual;
574 
575 			/* Terminate if end-of-message bit received from device */
576 			if ((buffer[8] & 0x01) && (actual >= n_characters))
577 				remaining = 0;
578 
579 			dev_dbg(dev, "Bulk-IN header: remaining(%zu), buf(%p), buffer(%p) done(%zu)\n", remaining,buf,buffer,done);
580 
581 
582 			/* Copy buffer to user space */
583 			if (copy_to_user(buf + done, &buffer[USBTMC_HEADER_SIZE], actual)) {
584 				/* There must have been an addressing problem */
585 				retval = -EFAULT;
586 				goto exit;
587 			}
588 			done += actual;
589 		}
590 		else  {
591 			if (actual > remaining)
592 				actual = remaining;
593 
594 			remaining -= actual;
595 
596 			dev_dbg(dev, "Bulk-IN header cont: actual(%u), done(%zu), remaining(%zu), buf(%p), buffer(%p)\n", actual, done, remaining,buf,buffer);
597 
598 			/* Copy buffer to user space */
599 			if (copy_to_user(buf + done, buffer, actual)) {
600 				/* There must have been an addressing problem */
601 				retval = -EFAULT;
602 				goto exit;
603 			}
604 			done += actual;
605 		}
606 	}
607 
608 	/* Update file position value */
609 	*f_pos = *f_pos + done;
610 	retval = done;
611 
612 exit:
613 	mutex_unlock(&data->io_mutex);
614 	kfree(buffer);
615 	return retval;
616 }
617 
usbtmc_write(struct file * filp,const char __user * buf,size_t count,loff_t * f_pos)618 static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
619 			    size_t count, loff_t *f_pos)
620 {
621 	struct usbtmc_device_data *data;
622 	u8 *buffer;
623 	int retval;
624 	int actual;
625 	unsigned long int n_bytes;
626 	int remaining;
627 	int done;
628 	int this_part;
629 
630 	data = filp->private_data;
631 
632 	buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
633 	if (!buffer)
634 		return -ENOMEM;
635 
636 	mutex_lock(&data->io_mutex);
637 	if (data->zombie) {
638 		retval = -ENODEV;
639 		goto exit;
640 	}
641 
642 	remaining = count;
643 	done = 0;
644 
645 	while (remaining > 0) {
646 		if (remaining > USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE) {
647 			this_part = USBTMC_SIZE_IOBUFFER - USBTMC_HEADER_SIZE;
648 			buffer[8] = 0;
649 		} else {
650 			this_part = remaining;
651 			buffer[8] = 1;
652 		}
653 
654 		/* Setup IO buffer for DEV_DEP_MSG_OUT message */
655 		buffer[0] = 1;
656 		buffer[1] = data->bTag;
657 		buffer[2] = ~data->bTag;
658 		buffer[3] = 0; /* Reserved */
659 		buffer[4] = this_part >> 0;
660 		buffer[5] = this_part >> 8;
661 		buffer[6] = this_part >> 16;
662 		buffer[7] = this_part >> 24;
663 		/* buffer[8] is set above... */
664 		buffer[9] = 0; /* Reserved */
665 		buffer[10] = 0; /* Reserved */
666 		buffer[11] = 0; /* Reserved */
667 
668 		if (copy_from_user(&buffer[USBTMC_HEADER_SIZE], buf + done, this_part)) {
669 			retval = -EFAULT;
670 			goto exit;
671 		}
672 
673 		n_bytes = roundup(USBTMC_HEADER_SIZE + this_part, 4);
674 		memset(buffer + USBTMC_HEADER_SIZE + this_part, 0, n_bytes - (USBTMC_HEADER_SIZE + this_part));
675 
676 		do {
677 			retval = usb_bulk_msg(data->usb_dev,
678 					      usb_sndbulkpipe(data->usb_dev,
679 							      data->bulk_out),
680 					      buffer, n_bytes,
681 					      &actual, USBTMC_TIMEOUT);
682 			if (retval != 0)
683 				break;
684 			n_bytes -= actual;
685 		} while (n_bytes);
686 
687 		data->bTag_last_write = data->bTag;
688 		data->bTag++;
689 
690 		if (!data->bTag)
691 			data->bTag++;
692 
693 		if (retval < 0) {
694 			dev_err(&data->intf->dev,
695 				"Unable to send data, error %d\n", retval);
696 			if (data->auto_abort)
697 				usbtmc_ioctl_abort_bulk_out(data);
698 			goto exit;
699 		}
700 
701 		remaining -= this_part;
702 		done += this_part;
703 	}
704 
705 	retval = count;
706 exit:
707 	mutex_unlock(&data->io_mutex);
708 	kfree(buffer);
709 	return retval;
710 }
711 
usbtmc_ioctl_clear(struct usbtmc_device_data * data)712 static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
713 {
714 	struct usb_host_interface *current_setting;
715 	struct usb_endpoint_descriptor *desc;
716 	struct device *dev;
717 	u8 *buffer;
718 	int rv;
719 	int n;
720 	int actual = 0;
721 	int max_size;
722 
723 	dev = &data->intf->dev;
724 
725 	dev_dbg(dev, "Sending INITIATE_CLEAR request\n");
726 
727 	buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
728 	if (!buffer)
729 		return -ENOMEM;
730 
731 	rv = usb_control_msg(data->usb_dev,
732 			     usb_rcvctrlpipe(data->usb_dev, 0),
733 			     USBTMC_REQUEST_INITIATE_CLEAR,
734 			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
735 			     0, 0, buffer, 1, USBTMC_TIMEOUT);
736 	if (rv < 0) {
737 		dev_err(dev, "usb_control_msg returned %d\n", rv);
738 		goto exit;
739 	}
740 
741 	dev_dbg(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
742 
743 	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
744 		dev_err(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
745 		rv = -EPERM;
746 		goto exit;
747 	}
748 
749 	max_size = 0;
750 	current_setting = data->intf->cur_altsetting;
751 	for (n = 0; n < current_setting->desc.bNumEndpoints; n++) {
752 		desc = &current_setting->endpoint[n].desc;
753 		if (desc->bEndpointAddress == data->bulk_in)
754 			max_size = usb_endpoint_maxp(desc);
755 	}
756 
757 	if (max_size == 0) {
758 		dev_err(dev, "Couldn't get wMaxPacketSize\n");
759 		rv = -EPERM;
760 		goto exit;
761 	}
762 
763 	dev_dbg(dev, "wMaxPacketSize is %d\n", max_size);
764 
765 	n = 0;
766 
767 usbtmc_clear_check_status:
768 
769 	dev_dbg(dev, "Sending CHECK_CLEAR_STATUS request\n");
770 
771 	rv = usb_control_msg(data->usb_dev,
772 			     usb_rcvctrlpipe(data->usb_dev, 0),
773 			     USBTMC_REQUEST_CHECK_CLEAR_STATUS,
774 			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
775 			     0, 0, buffer, 2, USBTMC_TIMEOUT);
776 	if (rv < 0) {
777 		dev_err(dev, "usb_control_msg returned %d\n", rv);
778 		goto exit;
779 	}
780 
781 	dev_dbg(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
782 
783 	if (buffer[0] == USBTMC_STATUS_SUCCESS)
784 		goto usbtmc_clear_bulk_out_halt;
785 
786 	if (buffer[0] != USBTMC_STATUS_PENDING) {
787 		dev_err(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
788 		rv = -EPERM;
789 		goto exit;
790 	}
791 
792 	if (buffer[1] == 1)
793 		do {
794 			dev_dbg(dev, "Reading from bulk in EP\n");
795 
796 			rv = usb_bulk_msg(data->usb_dev,
797 					  usb_rcvbulkpipe(data->usb_dev,
798 							  data->bulk_in),
799 					  buffer, USBTMC_SIZE_IOBUFFER,
800 					  &actual, USBTMC_TIMEOUT);
801 			n++;
802 
803 			if (rv < 0) {
804 				dev_err(dev, "usb_control_msg returned %d\n",
805 					rv);
806 				goto exit;
807 			}
808 		} while ((actual == max_size) &&
809 			  (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
810 
811 	if (actual == max_size) {
812 		dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
813 			USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
814 		rv = -EPERM;
815 		goto exit;
816 	}
817 
818 	goto usbtmc_clear_check_status;
819 
820 usbtmc_clear_bulk_out_halt:
821 
822 	rv = usb_clear_halt(data->usb_dev,
823 			    usb_sndbulkpipe(data->usb_dev, data->bulk_out));
824 	if (rv < 0) {
825 		dev_err(dev, "usb_control_msg returned %d\n", rv);
826 		goto exit;
827 	}
828 	rv = 0;
829 
830 exit:
831 	kfree(buffer);
832 	return rv;
833 }
834 
usbtmc_ioctl_clear_out_halt(struct usbtmc_device_data * data)835 static int usbtmc_ioctl_clear_out_halt(struct usbtmc_device_data *data)
836 {
837 	int rv;
838 
839 	rv = usb_clear_halt(data->usb_dev,
840 			    usb_sndbulkpipe(data->usb_dev, data->bulk_out));
841 
842 	if (rv < 0) {
843 		dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
844 			rv);
845 		return rv;
846 	}
847 	return 0;
848 }
849 
usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data * data)850 static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data)
851 {
852 	int rv;
853 
854 	rv = usb_clear_halt(data->usb_dev,
855 			    usb_rcvbulkpipe(data->usb_dev, data->bulk_in));
856 
857 	if (rv < 0) {
858 		dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
859 			rv);
860 		return rv;
861 	}
862 	return 0;
863 }
864 
get_capabilities(struct usbtmc_device_data * data)865 static int get_capabilities(struct usbtmc_device_data *data)
866 {
867 	struct device *dev = &data->usb_dev->dev;
868 	char *buffer;
869 	int rv = 0;
870 
871 	buffer = kmalloc(0x18, GFP_KERNEL);
872 	if (!buffer)
873 		return -ENOMEM;
874 
875 	rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0),
876 			     USBTMC_REQUEST_GET_CAPABILITIES,
877 			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
878 			     0, 0, buffer, 0x18, USBTMC_TIMEOUT);
879 	if (rv < 0) {
880 		dev_err(dev, "usb_control_msg returned %d\n", rv);
881 		goto err_out;
882 	}
883 
884 	dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
885 	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
886 		dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
887 		rv = -EPERM;
888 		goto err_out;
889 	}
890 	dev_dbg(dev, "Interface capabilities are %x\n", buffer[4]);
891 	dev_dbg(dev, "Device capabilities are %x\n", buffer[5]);
892 	dev_dbg(dev, "USB488 interface capabilities are %x\n", buffer[14]);
893 	dev_dbg(dev, "USB488 device capabilities are %x\n", buffer[15]);
894 
895 	data->capabilities.interface_capabilities = buffer[4];
896 	data->capabilities.device_capabilities = buffer[5];
897 	data->capabilities.usb488_interface_capabilities = buffer[14];
898 	data->capabilities.usb488_device_capabilities = buffer[15];
899 	rv = 0;
900 
901 err_out:
902 	kfree(buffer);
903 	return rv;
904 }
905 
906 #define capability_attribute(name)					\
907 static ssize_t name##_show(struct device *dev,				\
908 			   struct device_attribute *attr, char *buf)	\
909 {									\
910 	struct usb_interface *intf = to_usb_interface(dev);		\
911 	struct usbtmc_device_data *data = usb_get_intfdata(intf);	\
912 									\
913 	return sprintf(buf, "%d\n", data->capabilities.name);		\
914 }									\
915 static DEVICE_ATTR_RO(name)
916 
917 capability_attribute(interface_capabilities);
918 capability_attribute(device_capabilities);
919 capability_attribute(usb488_interface_capabilities);
920 capability_attribute(usb488_device_capabilities);
921 
922 static struct attribute *capability_attrs[] = {
923 	&dev_attr_interface_capabilities.attr,
924 	&dev_attr_device_capabilities.attr,
925 	&dev_attr_usb488_interface_capabilities.attr,
926 	&dev_attr_usb488_device_capabilities.attr,
927 	NULL,
928 };
929 
930 static struct attribute_group capability_attr_grp = {
931 	.attrs = capability_attrs,
932 };
933 
TermChar_show(struct device * dev,struct device_attribute * attr,char * buf)934 static ssize_t TermChar_show(struct device *dev,
935 			     struct device_attribute *attr, char *buf)
936 {
937 	struct usb_interface *intf = to_usb_interface(dev);
938 	struct usbtmc_device_data *data = usb_get_intfdata(intf);
939 
940 	return sprintf(buf, "%c\n", data->TermChar);
941 }
942 
TermChar_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)943 static ssize_t TermChar_store(struct device *dev,
944 			      struct device_attribute *attr,
945 			      const char *buf, size_t count)
946 {
947 	struct usb_interface *intf = to_usb_interface(dev);
948 	struct usbtmc_device_data *data = usb_get_intfdata(intf);
949 
950 	if (count < 1)
951 		return -EINVAL;
952 	data->TermChar = buf[0];
953 	return count;
954 }
955 static DEVICE_ATTR_RW(TermChar);
956 
957 #define data_attribute(name)						\
958 static ssize_t name##_show(struct device *dev,				\
959 			   struct device_attribute *attr, char *buf)	\
960 {									\
961 	struct usb_interface *intf = to_usb_interface(dev);		\
962 	struct usbtmc_device_data *data = usb_get_intfdata(intf);	\
963 									\
964 	return sprintf(buf, "%d\n", data->name);			\
965 }									\
966 static ssize_t name##_store(struct device *dev,				\
967 			    struct device_attribute *attr,		\
968 			    const char *buf, size_t count)		\
969 {									\
970 	struct usb_interface *intf = to_usb_interface(dev);		\
971 	struct usbtmc_device_data *data = usb_get_intfdata(intf);	\
972 	ssize_t result;							\
973 	unsigned val;							\
974 									\
975 	result = sscanf(buf, "%u\n", &val);				\
976 	if (result != 1)						\
977 		result = -EINVAL;					\
978 	data->name = val;						\
979 	if (result < 0)							\
980 		return result;						\
981 	else								\
982 		return count;						\
983 }									\
984 static DEVICE_ATTR_RW(name)
985 
986 data_attribute(TermCharEnabled);
987 data_attribute(auto_abort);
988 
989 static struct attribute *data_attrs[] = {
990 	&dev_attr_TermChar.attr,
991 	&dev_attr_TermCharEnabled.attr,
992 	&dev_attr_auto_abort.attr,
993 	NULL,
994 };
995 
996 static struct attribute_group data_attr_grp = {
997 	.attrs = data_attrs,
998 };
999 
usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data * data)1000 static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
1001 {
1002 	struct device *dev;
1003 	u8 *buffer;
1004 	int rv;
1005 
1006 	dev = &data->intf->dev;
1007 
1008 	buffer = kmalloc(2, GFP_KERNEL);
1009 	if (!buffer)
1010 		return -ENOMEM;
1011 
1012 	rv = usb_control_msg(data->usb_dev,
1013 			     usb_rcvctrlpipe(data->usb_dev, 0),
1014 			     USBTMC_REQUEST_INDICATOR_PULSE,
1015 			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1016 			     0, 0, buffer, 0x01, USBTMC_TIMEOUT);
1017 
1018 	if (rv < 0) {
1019 		dev_err(dev, "usb_control_msg returned %d\n", rv);
1020 		goto exit;
1021 	}
1022 
1023 	dev_dbg(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
1024 
1025 	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
1026 		dev_err(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
1027 		rv = -EPERM;
1028 		goto exit;
1029 	}
1030 	rv = 0;
1031 
1032 exit:
1033 	kfree(buffer);
1034 	return rv;
1035 }
1036 
usbtmc_ioctl(struct file * file,unsigned int cmd,unsigned long arg)1037 static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
1038 {
1039 	struct usbtmc_device_data *data;
1040 	int retval = -EBADRQC;
1041 
1042 	data = file->private_data;
1043 	mutex_lock(&data->io_mutex);
1044 	if (data->zombie) {
1045 		retval = -ENODEV;
1046 		goto skip_io_on_zombie;
1047 	}
1048 
1049 	switch (cmd) {
1050 	case USBTMC_IOCTL_CLEAR_OUT_HALT:
1051 		retval = usbtmc_ioctl_clear_out_halt(data);
1052 		break;
1053 
1054 	case USBTMC_IOCTL_CLEAR_IN_HALT:
1055 		retval = usbtmc_ioctl_clear_in_halt(data);
1056 		break;
1057 
1058 	case USBTMC_IOCTL_INDICATOR_PULSE:
1059 		retval = usbtmc_ioctl_indicator_pulse(data);
1060 		break;
1061 
1062 	case USBTMC_IOCTL_CLEAR:
1063 		retval = usbtmc_ioctl_clear(data);
1064 		break;
1065 
1066 	case USBTMC_IOCTL_ABORT_BULK_OUT:
1067 		retval = usbtmc_ioctl_abort_bulk_out(data);
1068 		break;
1069 
1070 	case USBTMC_IOCTL_ABORT_BULK_IN:
1071 		retval = usbtmc_ioctl_abort_bulk_in(data);
1072 		break;
1073 	}
1074 
1075 skip_io_on_zombie:
1076 	mutex_unlock(&data->io_mutex);
1077 	return retval;
1078 }
1079 
1080 static const struct file_operations fops = {
1081 	.owner		= THIS_MODULE,
1082 	.read		= usbtmc_read,
1083 	.write		= usbtmc_write,
1084 	.open		= usbtmc_open,
1085 	.release	= usbtmc_release,
1086 	.unlocked_ioctl	= usbtmc_ioctl,
1087 	.llseek		= default_llseek,
1088 };
1089 
1090 static struct usb_class_driver usbtmc_class = {
1091 	.name =		"usbtmc%d",
1092 	.fops =		&fops,
1093 	.minor_base =	USBTMC_MINOR_BASE,
1094 };
1095 
1096 
usbtmc_probe(struct usb_interface * intf,const struct usb_device_id * id)1097 static int usbtmc_probe(struct usb_interface *intf,
1098 			const struct usb_device_id *id)
1099 {
1100 	struct usbtmc_device_data *data;
1101 	struct usb_host_interface *iface_desc;
1102 	struct usb_endpoint_descriptor *endpoint;
1103 	int n;
1104 	int retcode;
1105 
1106 	dev_dbg(&intf->dev, "%s called\n", __func__);
1107 
1108 	data = kzalloc(sizeof(*data), GFP_KERNEL);
1109 	if (!data)
1110 		return -ENOMEM;
1111 
1112 	data->intf = intf;
1113 	data->id = id;
1114 	data->usb_dev = usb_get_dev(interface_to_usbdev(intf));
1115 	usb_set_intfdata(intf, data);
1116 	kref_init(&data->kref);
1117 	mutex_init(&data->io_mutex);
1118 	data->zombie = 0;
1119 
1120 	/* Determine if it is a Rigol or not */
1121 	data->rigol_quirk = 0;
1122 	dev_dbg(&intf->dev, "Trying to find if device Vendor 0x%04X Product 0x%04X has the RIGOL quirk\n",
1123 		le16_to_cpu(data->usb_dev->descriptor.idVendor),
1124 		le16_to_cpu(data->usb_dev->descriptor.idProduct));
1125 	for(n = 0; usbtmc_id_quirk[n].idVendor > 0; n++) {
1126 		if ((usbtmc_id_quirk[n].idVendor == le16_to_cpu(data->usb_dev->descriptor.idVendor)) &&
1127 		    (usbtmc_id_quirk[n].idProduct == le16_to_cpu(data->usb_dev->descriptor.idProduct))) {
1128 			dev_dbg(&intf->dev, "Setting this device as having the RIGOL quirk\n");
1129 			data->rigol_quirk = 1;
1130 			break;
1131 		}
1132 	}
1133 
1134 	/* Initialize USBTMC bTag and other fields */
1135 	data->bTag	= 1;
1136 	data->TermCharEnabled = 0;
1137 	data->TermChar = '\n';
1138 
1139 	/* USBTMC devices have only one setting, so use that */
1140 	iface_desc = data->intf->cur_altsetting;
1141 
1142 	/* Find bulk in endpoint */
1143 	for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1144 		endpoint = &iface_desc->endpoint[n].desc;
1145 
1146 		if (usb_endpoint_is_bulk_in(endpoint)) {
1147 			data->bulk_in = endpoint->bEndpointAddress;
1148 			dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n",
1149 				data->bulk_in);
1150 			break;
1151 		}
1152 	}
1153 
1154 	/* Find bulk out endpoint */
1155 	for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1156 		endpoint = &iface_desc->endpoint[n].desc;
1157 
1158 		if (usb_endpoint_is_bulk_out(endpoint)) {
1159 			data->bulk_out = endpoint->bEndpointAddress;
1160 			dev_dbg(&intf->dev, "Found Bulk out endpoint at %u\n",
1161 				data->bulk_out);
1162 			break;
1163 		}
1164 	}
1165 
1166 	if (!data->bulk_out || !data->bulk_in) {
1167 		dev_err(&intf->dev, "bulk endpoints not found\n");
1168 		retcode = -ENODEV;
1169 		goto err_put;
1170 	}
1171 
1172 	retcode = get_capabilities(data);
1173 	if (retcode)
1174 		dev_err(&intf->dev, "can't read capabilities\n");
1175 	else
1176 		retcode = sysfs_create_group(&intf->dev.kobj,
1177 					     &capability_attr_grp);
1178 
1179 	retcode = sysfs_create_group(&intf->dev.kobj, &data_attr_grp);
1180 
1181 	retcode = usb_register_dev(intf, &usbtmc_class);
1182 	if (retcode) {
1183 		dev_err(&intf->dev, "Not able to get a minor"
1184 			" (base %u, slice default): %d\n", USBTMC_MINOR_BASE,
1185 			retcode);
1186 		goto error_register;
1187 	}
1188 	dev_dbg(&intf->dev, "Using minor number %d\n", intf->minor);
1189 
1190 	return 0;
1191 
1192 error_register:
1193 	sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1194 	sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1195 err_put:
1196 	kref_put(&data->kref, usbtmc_delete);
1197 	return retcode;
1198 }
1199 
usbtmc_disconnect(struct usb_interface * intf)1200 static void usbtmc_disconnect(struct usb_interface *intf)
1201 {
1202 	struct usbtmc_device_data *data;
1203 
1204 	dev_dbg(&intf->dev, "usbtmc_disconnect called\n");
1205 
1206 	data = usb_get_intfdata(intf);
1207 	usb_deregister_dev(intf, &usbtmc_class);
1208 	sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1209 	sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1210 	mutex_lock(&data->io_mutex);
1211 	data->zombie = 1;
1212 	mutex_unlock(&data->io_mutex);
1213 	kref_put(&data->kref, usbtmc_delete);
1214 }
1215 
usbtmc_suspend(struct usb_interface * intf,pm_message_t message)1216 static int usbtmc_suspend(struct usb_interface *intf, pm_message_t message)
1217 {
1218 	/* this driver does not have pending URBs */
1219 	return 0;
1220 }
1221 
usbtmc_resume(struct usb_interface * intf)1222 static int usbtmc_resume(struct usb_interface *intf)
1223 {
1224 	return 0;
1225 }
1226 
1227 static struct usb_driver usbtmc_driver = {
1228 	.name		= "usbtmc",
1229 	.id_table	= usbtmc_devices,
1230 	.probe		= usbtmc_probe,
1231 	.disconnect	= usbtmc_disconnect,
1232 	.suspend	= usbtmc_suspend,
1233 	.resume		= usbtmc_resume,
1234 };
1235 
1236 module_usb_driver(usbtmc_driver);
1237 
1238 MODULE_LICENSE("GPL");
1239