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