usbtmc.c revision 5413aa467806578bf5f78a83893cb9426b815231 
1/**
2 * drivers/usb/class/usbtmc.c - USB Test & Measurment 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/fs.h>
25#include <linux/uaccess.h>
26#include <linux/kref.h>
27#include <linux/mutex.h>
28#include <linux/usb.h>
29#include <linux/usb/tmc.h>
30
31
32#define USBTMC_MINOR_BASE	176
33
34/*
35 * Size of driver internal IO buffer. Must be multiple of 4 and at least as
36 * large as wMaxPacketSize (which is usually 512 bytes).
37 */
38#define USBTMC_SIZE_IOBUFFER	2048
39
40/* Default USB timeout (in milliseconds) */
41#define USBTMC_TIMEOUT		10
42
43/*
44 * Maximum number of read cycles to empty bulk in endpoint during CLEAR and
45 * ABORT_BULK_IN requests. Ends the loop if (for whatever reason) a short
46 * packet is never read.
47 */
48#define USBTMC_MAX_READS_TO_CLEAR_BULK_IN	100
49
50static struct usb_device_id usbtmc_devices[] = {
51	{ USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 0), },
52	{ 0, } /* terminating entry */
53};
54MODULE_DEVICE_TABLE(usb, usbtmc_devices);
55
56/*
57 * This structure is the capabilities for the device
58 * See section 4.2.1.8 of the USBTMC specification for details.
59 */
60struct usbtmc_dev_capabilities {
61	__u8 interface_capabilities;
62	__u8 device_capabilities;
63	__u8 usb488_interface_capabilities;
64	__u8 usb488_device_capabilities;
65};
66
67/* This structure holds private data for each USBTMC device. One copy is
68 * allocated for each USBTMC device in the driver's probe function.
69 */
70struct usbtmc_device_data {
71	const struct usb_device_id *id;
72	struct usb_device *usb_dev;
73	struct usb_interface *intf;
74
75	unsigned int bulk_in;
76	unsigned int bulk_out;
77
78	u8 bTag;
79	u8 bTag_last_write;	/* needed for abort */
80	u8 bTag_last_read;	/* needed for abort */
81
82	/* attributes from the USB TMC spec for this device */
83	u8 TermChar;
84	bool TermCharEnabled;
85	bool auto_abort;
86
87	struct usbtmc_dev_capabilities	capabilities;
88	struct kref kref;
89	struct mutex io_mutex;	/* only one i/o function running at a time */
90};
91#define to_usbtmc_data(d) container_of(d, struct usbtmc_device_data, kref)
92
93/* Forward declarations */
94static struct usb_driver usbtmc_driver;
95
96static void usbtmc_delete(struct kref *kref)
97{
98	struct usbtmc_device_data *data = to_usbtmc_data(kref);
99
100	usb_put_dev(data->usb_dev);
101	kfree(data);
102}
103
104static int usbtmc_open(struct inode *inode, struct file *filp)
105{
106	struct usb_interface *intf;
107	struct usbtmc_device_data *data;
108	int retval = -ENODEV;
109
110	intf = usb_find_interface(&usbtmc_driver, iminor(inode));
111	if (!intf) {
112		printk(KERN_ERR KBUILD_MODNAME
113		       ": can not find device for minor %d", iminor(inode));
114		goto exit;
115	}
116
117	data = usb_get_intfdata(intf);
118	kref_get(&data->kref);
119
120	/* Store pointer in file structure's private data field */
121	filp->private_data = data;
122
123exit:
124	return retval;
125}
126
127static int usbtmc_release(struct inode *inode, struct file *file)
128{
129	struct usbtmc_device_data *data = file->private_data;
130
131	kref_put(&data->kref, usbtmc_delete);
132	return 0;
133}
134
135static int usbtmc_ioctl_abort_bulk_in(struct usbtmc_device_data *data)
136{
137	u8 *buffer;
138	struct device *dev;
139	int rv;
140	int n;
141	int actual;
142	struct usb_host_interface *current_setting;
143	int max_size;
144
145	dev = &data->intf->dev;
146	buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
147	if (!buffer)
148		return -ENOMEM;
149
150	rv = usb_control_msg(data->usb_dev,
151			     usb_rcvctrlpipe(data->usb_dev, 0),
152			     USBTMC_REQUEST_INITIATE_ABORT_BULK_IN,
153			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
154			     data->bTag_last_read, data->bulk_in,
155			     buffer, 2, USBTMC_TIMEOUT);
156
157	if (rv < 0) {
158		dev_err(dev, "usb_control_msg returned %d\n", rv);
159		goto exit;
160	}
161
162	dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
163
164	if (buffer[0] == USBTMC_STATUS_FAILED) {
165		rv = 0;
166		goto exit;
167	}
168
169	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
170		dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n",
171			buffer[0]);
172		rv = -EPERM;
173		goto exit;
174	}
175
176	max_size = 0;
177	current_setting = data->intf->cur_altsetting;
178	for (n = 0; n < current_setting->desc.bNumEndpoints; n++)
179		if (current_setting->endpoint[n].desc.bEndpointAddress ==
180			data->bulk_in)
181			max_size = le16_to_cpu(current_setting->endpoint[n].
182						desc.wMaxPacketSize);
183
184	if (max_size == 0) {
185		dev_err(dev, "Couldn't get wMaxPacketSize\n");
186		rv = -EPERM;
187		goto exit;
188	}
189
190	dev_dbg(&data->intf->dev, "wMaxPacketSize is %d\n", max_size);
191
192	n = 0;
193
194	do {
195		dev_dbg(dev, "Reading from bulk in EP\n");
196
197		rv = usb_bulk_msg(data->usb_dev,
198				  usb_rcvbulkpipe(data->usb_dev,
199						  data->bulk_in),
200				  buffer, USBTMC_SIZE_IOBUFFER,
201				  &actual, USBTMC_TIMEOUT);
202
203		n++;
204
205		if (rv < 0) {
206			dev_err(dev, "usb_bulk_msg returned %d\n", rv);
207			goto exit;
208		}
209	} while ((actual == max_size) &&
210		 (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
211
212	if (actual == max_size) {
213		dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
214			USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
215		rv = -EPERM;
216		goto exit;
217	}
218
219	n = 0;
220
221usbtmc_abort_bulk_in_status:
222	rv = usb_control_msg(data->usb_dev,
223			     usb_rcvctrlpipe(data->usb_dev, 0),
224			     USBTMC_REQUEST_CHECK_ABORT_BULK_IN_STATUS,
225			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
226			     0, data->bulk_in, buffer, 0x08,
227			     USBTMC_TIMEOUT);
228
229	if (rv < 0) {
230		dev_err(dev, "usb_control_msg returned %d\n", rv);
231		goto exit;
232	}
233
234	dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
235
236	if (buffer[0] == USBTMC_STATUS_SUCCESS) {
237		rv = 0;
238		goto exit;
239	}
240
241	if (buffer[0] != USBTMC_STATUS_PENDING) {
242		dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
243		rv = -EPERM;
244		goto exit;
245	}
246
247	if (buffer[1] == 1)
248		do {
249			dev_dbg(dev, "Reading from bulk in EP\n");
250
251			rv = usb_bulk_msg(data->usb_dev,
252					  usb_rcvbulkpipe(data->usb_dev,
253							  data->bulk_in),
254					  buffer, USBTMC_SIZE_IOBUFFER,
255					  &actual, USBTMC_TIMEOUT);
256
257			n++;
258
259			if (rv < 0) {
260				dev_err(dev, "usb_bulk_msg returned %d\n", rv);
261				goto exit;
262			}
263		} while ((actual = max_size) &&
264			 (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
265
266	if (actual == max_size) {
267		dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
268			USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
269		rv = -EPERM;
270		goto exit;
271	}
272
273	goto usbtmc_abort_bulk_in_status;
274
275exit:
276	kfree(buffer);
277	return rv;
278
279}
280
281static int usbtmc_ioctl_abort_bulk_out(struct usbtmc_device_data *data)
282{
283	struct device *dev;
284	u8 *buffer;
285	int rv;
286	int n;
287
288	dev = &data->intf->dev;
289
290	buffer = kmalloc(8, GFP_KERNEL);
291	if (!buffer)
292		return -ENOMEM;
293
294	rv = usb_control_msg(data->usb_dev,
295			     usb_rcvctrlpipe(data->usb_dev, 0),
296			     USBTMC_REQUEST_INITIATE_ABORT_BULK_OUT,
297			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
298			     data->bTag_last_write, data->bulk_out,
299			     buffer, 2, USBTMC_TIMEOUT);
300
301	if (rv < 0) {
302		dev_err(dev, "usb_control_msg returned %d\n", rv);
303		goto exit;
304	}
305
306	dev_dbg(dev, "INITIATE_ABORT_BULK_OUT returned %x\n", buffer[0]);
307
308	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
309		dev_err(dev, "INITIATE_ABORT_BULK_OUT returned %x\n",
310			buffer[0]);
311		rv = -EPERM;
312		goto exit;
313	}
314
315	n = 0;
316
317usbtmc_abort_bulk_out_check_status:
318	rv = usb_control_msg(data->usb_dev,
319			     usb_rcvctrlpipe(data->usb_dev, 0),
320			     USBTMC_REQUEST_CHECK_ABORT_BULK_OUT_STATUS,
321			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
322			     0, data->bulk_out, buffer, 0x08,
323			     USBTMC_TIMEOUT);
324	n++;
325	if (rv < 0) {
326		dev_err(dev, "usb_control_msg returned %d\n", rv);
327		goto exit;
328	}
329
330	dev_dbg(dev, "CHECK_ABORT_BULK_OUT returned %x\n", buffer[0]);
331
332	if (buffer[0] == USBTMC_STATUS_SUCCESS)
333		goto usbtmc_abort_bulk_out_clear_halt;
334
335	if ((buffer[0] == USBTMC_STATUS_PENDING) &&
336	    (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN))
337		goto usbtmc_abort_bulk_out_check_status;
338
339	rv = -EPERM;
340	goto exit;
341
342usbtmc_abort_bulk_out_clear_halt:
343	rv = usb_control_msg(data->usb_dev,
344			     usb_sndctrlpipe(data->usb_dev, 0),
345			     USB_REQ_CLEAR_FEATURE,
346			     USB_DIR_OUT | USB_TYPE_STANDARD |
347			     USB_RECIP_ENDPOINT,
348			     USB_ENDPOINT_HALT, data->bulk_out, buffer,
349			     0, USBTMC_TIMEOUT);
350
351	if (rv < 0) {
352		dev_err(dev, "usb_control_msg returned %d\n", rv);
353		goto exit;
354	}
355	rv = 0;
356
357exit:
358	kfree(buffer);
359	return rv;
360}
361
362static ssize_t usbtmc_read(struct file *filp, char __user *buf,
363			   size_t count, loff_t *f_pos)
364{
365	struct usbtmc_device_data *data;
366	struct device *dev;
367	unsigned long int n_characters;
368	u8 *buffer;
369	int actual;
370	int done;
371	int remaining;
372	int retval;
373	int this_part;
374
375	/* Get pointer to private data structure */
376	data = filp->private_data;
377	dev = &data->intf->dev;
378
379	buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
380	if (!buffer)
381		return -ENOMEM;
382
383	mutex_lock(&data->io_mutex);
384
385	remaining = count;
386	done = 0;
387
388	while (remaining > 0) {
389		if (remaining > USBTMC_SIZE_IOBUFFER - 12 - 3)
390			this_part = USBTMC_SIZE_IOBUFFER - 12 - 3;
391		else
392			this_part = remaining;
393
394		/* Setup IO buffer for 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] = (this_part - 12 - 3) & 255;
402		buffer[5] = ((this_part - 12 - 3) >> 8) & 255;
403		buffer[6] = ((this_part - 12 - 3) >> 16) & 255;
404		buffer[7] = ((this_part - 12 - 3) >> 24) & 255;
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, 12, &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		if (retval < 0) {
426			dev_err(dev, "usb_bulk_msg returned %d\n", retval);
427			if (data->auto_abort)
428				usbtmc_ioctl_abort_bulk_out(data);
429			goto exit;
430		}
431
432		/* Send bulk URB */
433		retval = usb_bulk_msg(data->usb_dev,
434				      usb_rcvbulkpipe(data->usb_dev,
435						      data->bulk_in),
436				      buffer, USBTMC_SIZE_IOBUFFER, &actual,
437				      USBTMC_TIMEOUT);
438
439		/* Store bTag (in case we need to abort) */
440		data->bTag_last_read = data->bTag;
441
442		if (retval < 0) {
443			dev_err(dev, "Unable to read data, error %d\n", retval);
444			if (data->auto_abort)
445				usbtmc_ioctl_abort_bulk_in(data);
446			goto exit;
447		}
448
449		/* How many characters did the instrument send? */
450		n_characters = buffer[4] +
451			       (buffer[5] << 8) +
452			       (buffer[6] << 16) +
453			       (buffer[7] << 24);
454
455		/* Copy buffer to user space */
456		if (copy_to_user(buf + done, &buffer[12], n_characters)) {
457			/* There must have been an addressing problem */
458			retval = -EFAULT;
459			goto exit;
460		}
461
462		done += n_characters;
463		if (n_characters < USBTMC_SIZE_IOBUFFER)
464			remaining = 0;
465	}
466
467	/* Update file position value */
468	*f_pos = *f_pos + done;
469	retval = done;
470
471exit:
472	mutex_unlock(&data->io_mutex);
473	kfree(buffer);
474	return retval;
475}
476
477static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
478			    size_t count, loff_t *f_pos)
479{
480	struct usbtmc_device_data *data;
481	u8 *buffer;
482	int retval;
483	int actual;
484	unsigned long int n_bytes;
485	int n;
486	int remaining;
487	int done;
488	int this_part;
489
490	data = filp->private_data;
491
492	buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
493	if (!buffer)
494		return -ENOMEM;
495
496	mutex_lock(&data->io_mutex);
497
498	remaining = count;
499	done = 0;
500
501	while (remaining > 0) {
502		if (remaining > USBTMC_SIZE_IOBUFFER - 12) {
503			this_part = USBTMC_SIZE_IOBUFFER - 12;
504			buffer[8] = 0;
505		} else {
506			this_part = remaining;
507			buffer[8] = 1;
508		}
509
510		/* Setup IO buffer for DEV_DEP_MSG_OUT message */
511		buffer[0] = 1;
512		buffer[1] = data->bTag;
513		buffer[2] = ~(data->bTag);
514		buffer[3] = 0; /* Reserved */
515		buffer[4] = this_part & 255;
516		buffer[5] = (this_part >> 8) & 255;
517		buffer[6] = (this_part >> 16) & 255;
518		buffer[7] = (this_part >> 24) & 255;
519		/* buffer[8] is set above... */
520		buffer[9] = 0; /* Reserved */
521		buffer[10] = 0; /* Reserved */
522		buffer[11] = 0; /* Reserved */
523
524		if (copy_from_user(&buffer[12], buf + done, this_part)) {
525			retval = -EFAULT;
526			goto exit;
527		}
528
529		n_bytes = 12 + this_part;
530		if (this_part % 4)
531			n_bytes += 4 - this_part % 4;
532			for (n = 12 + this_part; n < n_bytes; n++)
533				buffer[n] = 0;
534
535		retval = usb_bulk_msg(data->usb_dev,
536				      usb_sndbulkpipe(data->usb_dev,
537						      data->bulk_out),
538				      buffer, n_bytes, &actual, USBTMC_TIMEOUT);
539
540		data->bTag_last_write = data->bTag;
541		data->bTag++;
542
543		if (!data->bTag)
544			data->bTag++;
545
546		if (retval < 0) {
547			dev_err(&data->intf->dev,
548				"Unable to send data, error %d\n", retval);
549			if (data->auto_abort)
550				usbtmc_ioctl_abort_bulk_out(data);
551			goto exit;
552		}
553
554		remaining -= this_part;
555		done += this_part;
556	}
557
558	retval = count;
559exit:
560	mutex_unlock(&data->io_mutex);
561	kfree(buffer);
562	return retval;
563}
564
565static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
566{
567	struct usb_host_interface *current_setting;
568	struct usb_endpoint_descriptor *desc;
569	struct device *dev;
570	u8 *buffer;
571	int rv;
572	int n;
573	int actual;
574	int max_size;
575
576	dev = &data->intf->dev;
577
578	dev_dbg(dev, "Sending INITIATE_CLEAR request\n");
579
580	buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
581	if (!buffer)
582		return -ENOMEM;
583
584	rv = usb_control_msg(data->usb_dev,
585			     usb_rcvctrlpipe(data->usb_dev, 0),
586			     USBTMC_REQUEST_INITIATE_CLEAR,
587			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
588			     0, 0, buffer, 1, USBTMC_TIMEOUT);
589	if (rv < 0) {
590		dev_err(dev, "usb_control_msg returned %d\n", rv);
591		goto exit;
592	}
593
594	dev_dbg(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
595
596	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
597		dev_err(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
598		rv = -EPERM;
599		goto exit;
600	}
601
602	max_size = 0;
603	current_setting = data->intf->cur_altsetting;
604	for (n = 0; n < current_setting->desc.bNumEndpoints; n++) {
605		desc = &current_setting->endpoint[n].desc;
606		if (desc->bEndpointAddress == data->bulk_in)
607			max_size = le16_to_cpu(desc->wMaxPacketSize);
608	}
609
610	if (max_size == 0) {
611		dev_err(dev, "Couldn't get wMaxPacketSize\n");
612		rv = -EPERM;
613		goto exit;
614	}
615
616	dev_dbg(dev, "wMaxPacketSize is %d\n", max_size);
617
618	n = 0;
619
620usbtmc_clear_check_status:
621
622	dev_dbg(dev, "Sending CHECK_CLEAR_STATUS request\n");
623
624	rv = usb_control_msg(data->usb_dev,
625			     usb_rcvctrlpipe(data->usb_dev, 0),
626			     USBTMC_REQUEST_CHECK_CLEAR_STATUS,
627			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
628			     0, 0, buffer, 2, USBTMC_TIMEOUT);
629	if (rv < 0) {
630		dev_err(dev, "usb_control_msg returned %d\n", rv);
631		goto exit;
632	}
633
634	dev_dbg(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
635
636	if (buffer[0] == USBTMC_STATUS_SUCCESS)
637		goto usbtmc_clear_bulk_out_halt;
638
639	if (buffer[0] != USBTMC_STATUS_PENDING) {
640		dev_err(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
641		rv = -EPERM;
642		goto exit;
643	}
644
645	if (buffer[1] == 1)
646		do {
647			dev_dbg(dev, "Reading from bulk in EP\n");
648
649			rv = usb_bulk_msg(data->usb_dev,
650					  usb_rcvbulkpipe(data->usb_dev,
651							  data->bulk_in),
652					  buffer, USBTMC_SIZE_IOBUFFER,
653					  &actual, USBTMC_TIMEOUT);
654			n++;
655
656			if (rv < 0) {
657				dev_err(dev, "usb_control_msg returned %d\n",
658					rv);
659				goto exit;
660			}
661		} while ((actual == max_size) &&
662			  (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
663
664	if (actual == max_size) {
665		dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
666			USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
667		rv = -EPERM;
668		goto exit;
669	}
670
671	goto usbtmc_clear_check_status;
672
673usbtmc_clear_bulk_out_halt:
674
675	rv = usb_control_msg(data->usb_dev,
676			     usb_sndctrlpipe(data->usb_dev, 0),
677			     USB_REQ_CLEAR_FEATURE,
678			     USB_DIR_OUT | USB_TYPE_STANDARD |
679			     USB_RECIP_ENDPOINT,
680			     USB_ENDPOINT_HALT,
681			     data->bulk_out, buffer, 0,
682			     USBTMC_TIMEOUT);
683	if (rv < 0) {
684		dev_err(dev, "usb_control_msg returned %d\n", rv);
685		goto exit;
686	}
687	rv = 0;
688
689exit:
690	kfree(buffer);
691	return rv;
692}
693
694static int usbtmc_ioctl_clear_out_halt(struct usbtmc_device_data *data)
695{
696	u8 *buffer;
697	int rv;
698
699	buffer = kmalloc(2, GFP_KERNEL);
700	if (!buffer)
701		return -ENOMEM;
702
703	rv = usb_control_msg(data->usb_dev,
704			     usb_sndctrlpipe(data->usb_dev, 0),
705			     USB_REQ_CLEAR_FEATURE,
706			     USB_DIR_OUT | USB_TYPE_STANDARD |
707			     USB_RECIP_ENDPOINT,
708			     USB_ENDPOINT_HALT, data->bulk_out,
709			     buffer, 0, USBTMC_TIMEOUT);
710
711	if (rv < 0) {
712		dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
713			rv);
714		goto exit;
715	}
716	rv = 0;
717
718exit:
719	kfree(buffer);
720	return rv;
721}
722
723static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data)
724{
725	u8 *buffer;
726	int rv;
727
728	buffer = kmalloc(2, GFP_KERNEL);
729	if (!buffer)
730		return -ENOMEM;
731
732	rv = usb_control_msg(data->usb_dev, usb_sndctrlpipe(data->usb_dev, 0),
733			     USB_REQ_CLEAR_FEATURE,
734			     USB_DIR_OUT | USB_TYPE_STANDARD |
735			     USB_RECIP_ENDPOINT,
736			     USB_ENDPOINT_HALT, data->bulk_in, buffer, 0,
737			     USBTMC_TIMEOUT);
738
739	if (rv < 0) {
740		dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
741			rv);
742		goto exit;
743	}
744	rv = 0;
745
746exit:
747	kfree(buffer);
748	return rv;
749}
750
751static int get_capabilities(struct usbtmc_device_data *data)
752{
753	struct device *dev = &data->usb_dev->dev;
754	char *buffer;
755	int rv;
756
757	buffer = kmalloc(0x18, GFP_KERNEL);
758	if (!buffer)
759		return -ENOMEM;
760
761	rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0),
762			     USBTMC_REQUEST_GET_CAPABILITIES,
763			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
764			     0, 0, buffer, 0x18, USBTMC_TIMEOUT);
765	if (rv < 0) {
766		dev_err(dev, "usb_control_msg returned %d\n", rv);
767		return rv;
768	}
769
770	dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
771	dev_dbg(dev, "Interface capabilities are %x\n", buffer[4]);
772	dev_dbg(dev, "Device capabilities are %x\n", buffer[5]);
773	dev_dbg(dev, "USB488 interface capabilities are %x\n", buffer[14]);
774	dev_dbg(dev, "USB488 device capabilities are %x\n", buffer[15]);
775	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
776		dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
777		return -EPERM;
778	}
779
780	data->capabilities.interface_capabilities = buffer[4];
781	data->capabilities.device_capabilities = buffer[5];
782	data->capabilities.usb488_interface_capabilities = buffer[14];
783	data->capabilities.usb488_device_capabilities = buffer[15];
784
785	kfree(buffer);
786	return 0;
787}
788
789#define capability_attribute(name)					\
790static ssize_t show_##name(struct device *dev,				\
791			   struct device_attribute *attr, char *buf)	\
792{									\
793	struct usb_interface *intf = to_usb_interface(dev);		\
794	struct usbtmc_device_data *data = usb_get_intfdata(intf);	\
795									\
796	return sprintf(buf, "%d\n", data->capabilities.name);		\
797}									\
798static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
799
800capability_attribute(interface_capabilities);
801capability_attribute(device_capabilities);
802capability_attribute(usb488_interface_capabilities);
803capability_attribute(usb488_device_capabilities);
804
805static struct attribute *capability_attrs[] = {
806	&dev_attr_interface_capabilities.attr,
807	&dev_attr_device_capabilities.attr,
808	&dev_attr_usb488_interface_capabilities.attr,
809	&dev_attr_usb488_device_capabilities.attr,
810	NULL,
811};
812
813static struct attribute_group capability_attr_grp = {
814	.attrs = capability_attrs,
815};
816
817static ssize_t show_TermChar(struct device *dev,
818			     struct device_attribute *attr, char *buf)
819{
820	struct usb_interface *intf = to_usb_interface(dev);
821	struct usbtmc_device_data *data = usb_get_intfdata(intf);
822
823	return sprintf(buf, "%c\n", data->TermChar);
824}
825
826static ssize_t store_TermChar(struct device *dev,
827			      struct device_attribute *attr,
828			      const char *buf, size_t count)
829{
830	struct usb_interface *intf = to_usb_interface(dev);
831	struct usbtmc_device_data *data = usb_get_intfdata(intf);
832
833	if (count < 1)
834		return -EINVAL;
835	data->TermChar = buf[0];
836	return count;
837}
838static DEVICE_ATTR(TermChar, S_IRUGO, show_TermChar, store_TermChar);
839
840#define data_attribute(name)						\
841static ssize_t show_##name(struct device *dev,				\
842			   struct device_attribute *attr, char *buf)	\
843{									\
844	struct usb_interface *intf = to_usb_interface(dev);		\
845	struct usbtmc_device_data *data = usb_get_intfdata(intf);	\
846									\
847	return sprintf(buf, "%d\n", data->name);			\
848}									\
849static ssize_t store_##name(struct device *dev,				\
850			    struct device_attribute *attr,		\
851			    const char *buf, size_t count)		\
852{									\
853	struct usb_interface *intf = to_usb_interface(dev);		\
854	struct usbtmc_device_data *data = usb_get_intfdata(intf);	\
855	ssize_t result;							\
856	unsigned val;							\
857									\
858	result = sscanf(buf, "%u\n", &val);				\
859	if (result != 1)						\
860		result = -EINVAL;					\
861	data->name = val;						\
862	if (result < 0)							\
863		return result;						\
864	else								\
865		return count;						\
866}									\
867static DEVICE_ATTR(name, S_IRUGO, show_##name, store_##name)
868
869data_attribute(TermCharEnabled);
870data_attribute(auto_abort);
871
872static struct attribute *data_attrs[] = {
873	&dev_attr_TermChar.attr,
874	&dev_attr_TermCharEnabled.attr,
875	&dev_attr_auto_abort.attr,
876	NULL,
877};
878
879static struct attribute_group data_attr_grp = {
880	.attrs = data_attrs,
881};
882
883static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
884{
885	struct device *dev;
886	u8 *buffer;
887	int rv;
888
889	dev = &data->intf->dev;
890
891	buffer = kmalloc(2, GFP_KERNEL);
892	if (!buffer)
893		return -ENOMEM;
894
895	rv = usb_control_msg(data->usb_dev,
896			     usb_rcvctrlpipe(data->usb_dev, 0),
897			     USBTMC_REQUEST_INDICATOR_PULSE,
898			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
899			     0, 0, buffer, 0x01, USBTMC_TIMEOUT);
900
901	if (rv < 0) {
902		dev_err(dev, "usb_control_msg returned %d\n", rv);
903		goto exit;
904	}
905
906	dev_dbg(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
907
908	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
909		dev_err(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
910		rv = -EPERM;
911		goto exit;
912	}
913	rv = 0;
914
915exit:
916	kfree(buffer);
917	return rv;
918}
919
920static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
921{
922	struct usbtmc_device_data *data;
923	int retval = -EBADRQC;
924
925	data = file->private_data;
926	mutex_lock(&data->io_mutex);
927
928	switch (cmd) {
929	case USBTMC_IOCTL_CLEAR_OUT_HALT:
930		retval = usbtmc_ioctl_clear_out_halt(data);
931
932	case USBTMC_IOCTL_CLEAR_IN_HALT:
933		retval = usbtmc_ioctl_clear_in_halt(data);
934
935	case USBTMC_IOCTL_INDICATOR_PULSE:
936		retval = usbtmc_ioctl_indicator_pulse(data);
937
938	case USBTMC_IOCTL_CLEAR:
939		retval = usbtmc_ioctl_clear(data);
940
941	case USBTMC_IOCTL_ABORT_BULK_OUT:
942		retval = usbtmc_ioctl_abort_bulk_out(data);
943
944	case USBTMC_IOCTL_ABORT_BULK_IN:
945		retval = usbtmc_ioctl_abort_bulk_in(data);
946	}
947
948	mutex_unlock(&data->io_mutex);
949	return retval;
950}
951
952static struct file_operations fops = {
953	.owner		= THIS_MODULE,
954	.read		= usbtmc_read,
955	.write		= usbtmc_write,
956	.open		= usbtmc_open,
957	.release	= usbtmc_release,
958	.unlocked_ioctl	= usbtmc_ioctl,
959};
960
961static struct usb_class_driver usbtmc_class = {
962	.name =		"usbtmc%d",
963	.fops =		&fops,
964	.minor_base =	USBTMC_MINOR_BASE,
965};
966
967
968static int usbtmc_probe(struct usb_interface *intf,
969			const struct usb_device_id *id)
970{
971	struct usbtmc_device_data *data;
972	struct usb_host_interface *iface_desc;
973	struct usb_endpoint_descriptor *endpoint;
974	int n;
975	int retcode;
976
977	dev_dbg(&intf->dev, "%s called\n", __func__);
978
979	data = kmalloc(sizeof(struct usbtmc_device_data), GFP_KERNEL);
980	if (!data) {
981		dev_err(&intf->dev, "Unable to allocate kernel memory\n");
982		return -ENOMEM;
983	}
984
985	data->intf = intf;
986	data->id = id;
987	data->usb_dev = usb_get_dev(interface_to_usbdev(intf));
988	usb_set_intfdata(intf, data);
989	kref_init(&data->kref);
990	mutex_init(&data->io_mutex);
991
992	/* Initialize USBTMC bTag and other fields */
993	data->bTag	= 1;
994	data->TermCharEnabled = 0;
995	data->TermChar = '\n';
996
997	/* USBTMC devices have only one setting, so use that */
998	iface_desc = data->intf->cur_altsetting;
999
1000	/* Find bulk in endpoint */
1001	for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1002		endpoint = &iface_desc->endpoint[n].desc;
1003
1004		if (usb_endpoint_is_bulk_in(endpoint)) {
1005			data->bulk_in = endpoint->bEndpointAddress;
1006			dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n",
1007				data->bulk_in);
1008			break;
1009		}
1010	}
1011
1012	/* Find bulk out endpoint */
1013	for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1014		endpoint = &iface_desc->endpoint[n].desc;
1015
1016		if (usb_endpoint_is_bulk_out(endpoint)) {
1017			data->bulk_out = endpoint->bEndpointAddress;
1018			dev_dbg(&intf->dev, "Found Bulk out endpoint at %u\n",
1019				data->bulk_out);
1020			break;
1021		}
1022	}
1023
1024	retcode = get_capabilities(data);
1025	if (retcode)
1026		dev_err(&intf->dev, "can't read capabilities\n");
1027	else
1028		retcode = sysfs_create_group(&intf->dev.kobj,
1029					     &capability_attr_grp);
1030
1031	retcode = sysfs_create_group(&intf->dev.kobj, &data_attr_grp);
1032
1033	retcode = usb_register_dev(intf, &usbtmc_class);
1034	if (retcode) {
1035		dev_err(&intf->dev, "Not able to get a minor"
1036			" (base %u, slice default): %d\n", USBTMC_MINOR_BASE,
1037			retcode);
1038		goto error_register;
1039	}
1040	dev_dbg(&intf->dev, "Using minor number %d\n", intf->minor);
1041
1042	return 0;
1043
1044error_register:
1045	sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1046	sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1047	kref_put(&data->kref, usbtmc_delete);
1048	return retcode;
1049}
1050
1051static void usbtmc_disconnect(struct usb_interface *intf)
1052{
1053	struct usbtmc_device_data *data;
1054
1055	dev_dbg(&intf->dev, "usbtmc_disconnect called\n");
1056
1057	data = usb_get_intfdata(intf);
1058	usb_deregister_dev(intf, &usbtmc_class);
1059	sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1060	sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1061	kref_put(&data->kref, usbtmc_delete);
1062}
1063
1064static struct usb_driver usbtmc_driver = {
1065	.name		= "usbtmc",
1066	.id_table	= usbtmc_devices,
1067	.probe		= usbtmc_probe,
1068	.disconnect	= usbtmc_disconnect
1069};
1070
1071static int __init usbtmc_init(void)
1072{
1073	int retcode;
1074
1075	retcode = usb_register(&usbtmc_driver);
1076	if (retcode)
1077		printk(KERN_ERR KBUILD_MODNAME": Unable to register driver\n");
1078	return retcode;
1079}
1080module_init(usbtmc_init);
1081
1082static void __exit usbtmc_exit(void)
1083{
1084	usb_deregister(&usbtmc_driver);
1085}
1086module_exit(usbtmc_exit);
1087
1088MODULE_LICENSE("GPL");
1089