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v3.1
   1/**
   2 * drivers/usb/class/usbtmc.c - USB Test & Measurement class driver
   3 *
   4 * Copyright (C) 2007 Stefan Kopp, Gechingen, Germany
   5 * Copyright (C) 2008 Novell, Inc.
   6 * Copyright (C) 2008 Greg Kroah-Hartman <gregkh@suse.de>
   7 *
   8 * This program is free software; you can redistribute it and/or
   9 * modify it under the terms of the GNU General Public License
  10 * as published by the Free Software Foundation; either version 2
  11 * of the License, or (at your option) any later version.
  12 *
  13 * This program is distributed in the hope that it will be useful,
  14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 * GNU General Public License for more details.
  17 *
  18 * The GNU General Public License is available at
  19 * http://www.gnu.org/copyleft/gpl.html.
  20 */
  21
  22#include <linux/init.h>
  23#include <linux/module.h>
  24#include <linux/kernel.h>
  25#include <linux/fs.h>
  26#include <linux/uaccess.h>
  27#include <linux/kref.h>
  28#include <linux/slab.h>
  29#include <linux/mutex.h>
  30#include <linux/usb.h>
  31#include <linux/usb/tmc.h>
  32
  33
  34#define USBTMC_MINOR_BASE	176
  35
  36/*
  37 * Size of driver internal IO buffer. Must be multiple of 4 and at least as
  38 * large as wMaxPacketSize (which is usually 512 bytes).
  39 */
  40#define USBTMC_SIZE_IOBUFFER	2048
  41
  42/* Default USB timeout (in milliseconds) */
  43#define USBTMC_TIMEOUT		5000
  44
  45/*
  46 * Maximum number of read cycles to empty bulk in endpoint during CLEAR and
  47 * ABORT_BULK_IN requests. Ends the loop if (for whatever reason) a short
  48 * packet is never read.
  49 */
  50#define USBTMC_MAX_READS_TO_CLEAR_BULK_IN	100
  51
  52static const struct usb_device_id usbtmc_devices[] = {
  53	{ USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 0), },
  54	{ USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 1), },
  55	{ 0, } /* terminating entry */
  56};
  57MODULE_DEVICE_TABLE(usb, usbtmc_devices);
  58
  59/*
  60 * This structure is the capabilities for the device
  61 * See section 4.2.1.8 of the USBTMC specification,
  62 * and section 4.2.2 of the USBTMC usb488 subclass
  63 * specification for details.
  64 */
  65struct usbtmc_dev_capabilities {
  66	__u8 interface_capabilities;
  67	__u8 device_capabilities;
  68	__u8 usb488_interface_capabilities;
  69	__u8 usb488_device_capabilities;
  70};
  71
  72/* This structure holds private data for each USBTMC device. One copy is
  73 * allocated for each USBTMC device in the driver's probe function.
  74 */
  75struct usbtmc_device_data {
  76	const struct usb_device_id *id;
  77	struct usb_device *usb_dev;
  78	struct usb_interface *intf;
  79
  80	unsigned int bulk_in;
  81	unsigned int bulk_out;
  82
  83	u8 bTag;
  84	u8 bTag_last_write;	/* needed for abort */
  85	u8 bTag_last_read;	/* needed for abort */
  86
  87	/* attributes from the USB TMC spec for this device */
  88	u8 TermChar;
  89	bool TermCharEnabled;
  90	bool auto_abort;
  91
  92	bool zombie; /* fd of disconnected device */
  93
  94	struct usbtmc_dev_capabilities	capabilities;
  95	struct kref kref;
  96	struct mutex io_mutex;	/* only one i/o function running at a time */
  97};
  98#define to_usbtmc_data(d) container_of(d, struct usbtmc_device_data, kref)
  99
 100/* Forward declarations */
 101static struct usb_driver usbtmc_driver;
 102
 103static void usbtmc_delete(struct kref *kref)
 104{
 105	struct usbtmc_device_data *data = to_usbtmc_data(kref);
 106
 107	usb_put_dev(data->usb_dev);
 108	kfree(data);
 109}
 110
 111static int usbtmc_open(struct inode *inode, struct file *filp)
 112{
 113	struct usb_interface *intf;
 114	struct usbtmc_device_data *data;
 115	int retval = 0;
 116
 117	intf = usb_find_interface(&usbtmc_driver, iminor(inode));
 118	if (!intf) {
 119		printk(KERN_ERR KBUILD_MODNAME
 120		       ": can not find device for minor %d", iminor(inode));
 121		retval = -ENODEV;
 122		goto exit;
 123	}
 124
 125	data = usb_get_intfdata(intf);
 126	kref_get(&data->kref);
 127
 128	/* Store pointer in file structure's private data field */
 129	filp->private_data = data;
 130
 131exit:
 132	return retval;
 133}
 134
 135static int usbtmc_release(struct inode *inode, struct file *file)
 136{
 137	struct usbtmc_device_data *data = file->private_data;
 138
 139	kref_put(&data->kref, usbtmc_delete);
 140	return 0;
 141}
 142
 143static int usbtmc_ioctl_abort_bulk_in(struct usbtmc_device_data *data)
 144{
 145	u8 *buffer;
 146	struct device *dev;
 147	int rv;
 148	int n;
 149	int actual;
 150	struct usb_host_interface *current_setting;
 151	int max_size;
 152
 153	dev = &data->intf->dev;
 154	buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 155	if (!buffer)
 156		return -ENOMEM;
 157
 158	rv = usb_control_msg(data->usb_dev,
 159			     usb_rcvctrlpipe(data->usb_dev, 0),
 160			     USBTMC_REQUEST_INITIATE_ABORT_BULK_IN,
 161			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 162			     data->bTag_last_read, data->bulk_in,
 163			     buffer, 2, USBTMC_TIMEOUT);
 164
 165	if (rv < 0) {
 166		dev_err(dev, "usb_control_msg returned %d\n", rv);
 167		goto exit;
 168	}
 169
 170	dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 171
 172	if (buffer[0] == USBTMC_STATUS_FAILED) {
 173		rv = 0;
 174		goto exit;
 175	}
 176
 177	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 178		dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n",
 179			buffer[0]);
 180		rv = -EPERM;
 181		goto exit;
 182	}
 183
 184	max_size = 0;
 185	current_setting = data->intf->cur_altsetting;
 186	for (n = 0; n < current_setting->desc.bNumEndpoints; n++)
 187		if (current_setting->endpoint[n].desc.bEndpointAddress ==
 188			data->bulk_in)
 189			max_size = le16_to_cpu(current_setting->endpoint[n].
 190						desc.wMaxPacketSize);
 191
 192	if (max_size == 0) {
 193		dev_err(dev, "Couldn't get wMaxPacketSize\n");
 194		rv = -EPERM;
 195		goto exit;
 196	}
 197
 198	dev_dbg(&data->intf->dev, "wMaxPacketSize is %d\n", max_size);
 199
 200	n = 0;
 201
 202	do {
 203		dev_dbg(dev, "Reading from bulk in EP\n");
 204
 205		rv = usb_bulk_msg(data->usb_dev,
 206				  usb_rcvbulkpipe(data->usb_dev,
 207						  data->bulk_in),
 208				  buffer, USBTMC_SIZE_IOBUFFER,
 209				  &actual, USBTMC_TIMEOUT);
 210
 211		n++;
 212
 213		if (rv < 0) {
 214			dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 215			goto exit;
 216		}
 217	} while ((actual == max_size) &&
 218		 (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 219
 220	if (actual == max_size) {
 221		dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 222			USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 223		rv = -EPERM;
 224		goto exit;
 225	}
 226
 227	n = 0;
 228
 229usbtmc_abort_bulk_in_status:
 230	rv = usb_control_msg(data->usb_dev,
 231			     usb_rcvctrlpipe(data->usb_dev, 0),
 232			     USBTMC_REQUEST_CHECK_ABORT_BULK_IN_STATUS,
 233			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 234			     0, data->bulk_in, buffer, 0x08,
 235			     USBTMC_TIMEOUT);
 236
 237	if (rv < 0) {
 238		dev_err(dev, "usb_control_msg returned %d\n", rv);
 239		goto exit;
 240	}
 241
 242	dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 243
 244	if (buffer[0] == USBTMC_STATUS_SUCCESS) {
 245		rv = 0;
 246		goto exit;
 247	}
 248
 249	if (buffer[0] != USBTMC_STATUS_PENDING) {
 250		dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 251		rv = -EPERM;
 252		goto exit;
 253	}
 254
 255	if (buffer[1] == 1)
 256		do {
 257			dev_dbg(dev, "Reading from bulk in EP\n");
 258
 259			rv = usb_bulk_msg(data->usb_dev,
 260					  usb_rcvbulkpipe(data->usb_dev,
 261							  data->bulk_in),
 262					  buffer, USBTMC_SIZE_IOBUFFER,
 263					  &actual, USBTMC_TIMEOUT);
 264
 265			n++;
 266
 267			if (rv < 0) {
 268				dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 269				goto exit;
 270			}
 271		} while ((actual == max_size) &&
 272			 (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 273
 274	if (actual == max_size) {
 275		dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 276			USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 277		rv = -EPERM;
 278		goto exit;
 279	}
 280
 281	goto usbtmc_abort_bulk_in_status;
 282
 283exit:
 284	kfree(buffer);
 285	return rv;
 286
 287}
 288
 289static int usbtmc_ioctl_abort_bulk_out(struct usbtmc_device_data *data)
 290{
 291	struct device *dev;
 292	u8 *buffer;
 293	int rv;
 294	int n;
 295
 296	dev = &data->intf->dev;
 297
 298	buffer = kmalloc(8, GFP_KERNEL);
 299	if (!buffer)
 300		return -ENOMEM;
 301
 302	rv = usb_control_msg(data->usb_dev,
 303			     usb_rcvctrlpipe(data->usb_dev, 0),
 304			     USBTMC_REQUEST_INITIATE_ABORT_BULK_OUT,
 305			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 306			     data->bTag_last_write, data->bulk_out,
 307			     buffer, 2, USBTMC_TIMEOUT);
 308
 309	if (rv < 0) {
 310		dev_err(dev, "usb_control_msg returned %d\n", rv);
 311		goto exit;
 312	}
 313
 314	dev_dbg(dev, "INITIATE_ABORT_BULK_OUT returned %x\n", buffer[0]);
 315
 316	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 317		dev_err(dev, "INITIATE_ABORT_BULK_OUT returned %x\n",
 318			buffer[0]);
 319		rv = -EPERM;
 320		goto exit;
 321	}
 322
 323	n = 0;
 324
 325usbtmc_abort_bulk_out_check_status:
 326	rv = usb_control_msg(data->usb_dev,
 327			     usb_rcvctrlpipe(data->usb_dev, 0),
 328			     USBTMC_REQUEST_CHECK_ABORT_BULK_OUT_STATUS,
 329			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 330			     0, data->bulk_out, buffer, 0x08,
 331			     USBTMC_TIMEOUT);
 332	n++;
 333	if (rv < 0) {
 334		dev_err(dev, "usb_control_msg returned %d\n", rv);
 335		goto exit;
 336	}
 337
 338	dev_dbg(dev, "CHECK_ABORT_BULK_OUT returned %x\n", buffer[0]);
 339
 340	if (buffer[0] == USBTMC_STATUS_SUCCESS)
 341		goto usbtmc_abort_bulk_out_clear_halt;
 342
 343	if ((buffer[0] == USBTMC_STATUS_PENDING) &&
 344	    (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN))
 345		goto usbtmc_abort_bulk_out_check_status;
 346
 347	rv = -EPERM;
 348	goto exit;
 349
 350usbtmc_abort_bulk_out_clear_halt:
 351	rv = usb_clear_halt(data->usb_dev,
 352			    usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 353
 354	if (rv < 0) {
 355		dev_err(dev, "usb_control_msg returned %d\n", rv);
 356		goto exit;
 357	}
 358	rv = 0;
 359
 360exit:
 361	kfree(buffer);
 362	return rv;
 363}
 364
 365static ssize_t usbtmc_read(struct file *filp, char __user *buf,
 366			   size_t count, loff_t *f_pos)
 367{
 368	struct usbtmc_device_data *data;
 369	struct device *dev;
 370	u32 n_characters;
 371	u8 *buffer;
 372	int actual;
 373	size_t done;
 374	size_t remaining;
 375	int retval;
 376	size_t this_part;
 377
 378	/* Get pointer to private data structure */
 379	data = filp->private_data;
 380	dev = &data->intf->dev;
 381
 382	buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 383	if (!buffer)
 384		return -ENOMEM;
 385
 386	mutex_lock(&data->io_mutex);
 387	if (data->zombie) {
 388		retval = -ENODEV;
 389		goto exit;
 390	}
 391
 392	remaining = count;
 393	done = 0;
 394
 395	while (remaining > 0) {
 396		if (remaining > USBTMC_SIZE_IOBUFFER - 12 - 3)
 397			this_part = USBTMC_SIZE_IOBUFFER - 12 - 3;
 398		else
 399			this_part = remaining;
 400
 401		/* Setup IO buffer for DEV_DEP_MSG_IN message
 402		 * Refer to class specs for details
 403		 */
 404		buffer[0] = 2;
 405		buffer[1] = data->bTag;
 406		buffer[2] = ~(data->bTag);
 407		buffer[3] = 0; /* Reserved */
 408		buffer[4] = (this_part) & 255;
 409		buffer[5] = ((this_part) >> 8) & 255;
 410		buffer[6] = ((this_part) >> 16) & 255;
 411		buffer[7] = ((this_part) >> 24) & 255;
 412		buffer[8] = data->TermCharEnabled * 2;
 413		/* Use term character? */
 414		buffer[9] = data->TermChar;
 415		buffer[10] = 0; /* Reserved */
 416		buffer[11] = 0; /* Reserved */
 417
 418		/* Send bulk URB */
 419		retval = usb_bulk_msg(data->usb_dev,
 420				      usb_sndbulkpipe(data->usb_dev,
 421						      data->bulk_out),
 422				      buffer, 12, &actual, USBTMC_TIMEOUT);
 423
 424		/* Store bTag (in case we need to abort) */
 425		data->bTag_last_write = data->bTag;
 426
 427		/* Increment bTag -- and increment again if zero */
 428		data->bTag++;
 429		if (!data->bTag)
 430			(data->bTag)++;
 431
 432		if (retval < 0) {
 433			dev_err(dev, "usb_bulk_msg returned %d\n", retval);
 434			if (data->auto_abort)
 435				usbtmc_ioctl_abort_bulk_out(data);
 436			goto exit;
 437		}
 438
 439		/* Send bulk URB */
 440		retval = usb_bulk_msg(data->usb_dev,
 441				      usb_rcvbulkpipe(data->usb_dev,
 442						      data->bulk_in),
 443				      buffer, USBTMC_SIZE_IOBUFFER, &actual,
 444				      USBTMC_TIMEOUT);
 445
 446		/* Store bTag (in case we need to abort) */
 447		data->bTag_last_read = data->bTag;
 448
 449		if (retval < 0) {
 450			dev_err(dev, "Unable to read data, error %d\n", retval);
 451			if (data->auto_abort)
 452				usbtmc_ioctl_abort_bulk_in(data);
 453			goto exit;
 454		}
 455
 456		/* How many characters did the instrument send? */
 457		n_characters = buffer[4] +
 458			       (buffer[5] << 8) +
 459			       (buffer[6] << 16) +
 460			       (buffer[7] << 24);
 461
 462		/* Ensure the instrument doesn't lie about it */
 463		if(n_characters > actual - 12) {
 464			dev_err(dev, "Device lies about message size: %u > %d\n", n_characters, actual - 12);
 465			n_characters = actual - 12;
 466		}
 467
 468		/* Ensure the instrument doesn't send more back than requested */
 469		if(n_characters > this_part) {
 470			dev_err(dev, "Device returns more than requested: %zu > %zu\n", done + n_characters, done + this_part);
 471			n_characters = this_part;
 472		}
 473
 474		/* Bound amount of data received by amount of data requested */
 475		if (n_characters > this_part)
 476			n_characters = this_part;
 477
 478		/* Copy buffer to user space */
 479		if (copy_to_user(buf + done, &buffer[12], n_characters)) {
 480			/* There must have been an addressing problem */
 481			retval = -EFAULT;
 482			goto exit;
 483		}
 484
 485		done += n_characters;
 486		/* Terminate if end-of-message bit received from device */
 487		if ((buffer[8] &  0x01) && (actual >= n_characters + 12))
 488			remaining = 0;
 489		else
 490			remaining -= n_characters;
 491	}
 492
 493	/* Update file position value */
 494	*f_pos = *f_pos + done;
 495	retval = done;
 496
 497exit:
 498	mutex_unlock(&data->io_mutex);
 499	kfree(buffer);
 500	return retval;
 501}
 502
 503static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
 504			    size_t count, loff_t *f_pos)
 505{
 506	struct usbtmc_device_data *data;
 507	u8 *buffer;
 508	int retval;
 509	int actual;
 510	unsigned long int n_bytes;
 511	int remaining;
 512	int done;
 513	int this_part;
 514
 515	data = filp->private_data;
 516
 517	buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 518	if (!buffer)
 519		return -ENOMEM;
 520
 521	mutex_lock(&data->io_mutex);
 522	if (data->zombie) {
 523		retval = -ENODEV;
 524		goto exit;
 525	}
 526
 527	remaining = count;
 528	done = 0;
 529
 530	while (remaining > 0) {
 531		if (remaining > USBTMC_SIZE_IOBUFFER - 12) {
 532			this_part = USBTMC_SIZE_IOBUFFER - 12;
 533			buffer[8] = 0;
 534		} else {
 535			this_part = remaining;
 536			buffer[8] = 1;
 537		}
 538
 539		/* Setup IO buffer for DEV_DEP_MSG_OUT message */
 540		buffer[0] = 1;
 541		buffer[1] = data->bTag;
 542		buffer[2] = ~(data->bTag);
 543		buffer[3] = 0; /* Reserved */
 544		buffer[4] = this_part & 255;
 545		buffer[5] = (this_part >> 8) & 255;
 546		buffer[6] = (this_part >> 16) & 255;
 547		buffer[7] = (this_part >> 24) & 255;
 548		/* buffer[8] is set above... */
 549		buffer[9] = 0; /* Reserved */
 550		buffer[10] = 0; /* Reserved */
 551		buffer[11] = 0; /* Reserved */
 552
 553		if (copy_from_user(&buffer[12], buf + done, this_part)) {
 554			retval = -EFAULT;
 555			goto exit;
 556		}
 557
 558		n_bytes = roundup(12 + this_part, 4);
 559		memset(buffer + 12 + this_part, 0, n_bytes - (12 + this_part));
 560
 561		do {
 562			retval = usb_bulk_msg(data->usb_dev,
 563					      usb_sndbulkpipe(data->usb_dev,
 564							      data->bulk_out),
 565					      buffer, n_bytes,
 566					      &actual, USBTMC_TIMEOUT);
 567			if (retval != 0)
 568				break;
 569			n_bytes -= actual;
 570		} while (n_bytes);
 571
 572		data->bTag_last_write = data->bTag;
 573		data->bTag++;
 574
 575		if (!data->bTag)
 576			data->bTag++;
 577
 578		if (retval < 0) {
 579			dev_err(&data->intf->dev,
 580				"Unable to send data, error %d\n", retval);
 581			if (data->auto_abort)
 582				usbtmc_ioctl_abort_bulk_out(data);
 583			goto exit;
 584		}
 585
 586		remaining -= this_part;
 587		done += this_part;
 588	}
 589
 590	retval = count;
 591exit:
 592	mutex_unlock(&data->io_mutex);
 593	kfree(buffer);
 594	return retval;
 595}
 596
 597static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
 598{
 599	struct usb_host_interface *current_setting;
 600	struct usb_endpoint_descriptor *desc;
 601	struct device *dev;
 602	u8 *buffer;
 603	int rv;
 604	int n;
 605	int actual;
 606	int max_size;
 607
 608	dev = &data->intf->dev;
 609
 610	dev_dbg(dev, "Sending INITIATE_CLEAR request\n");
 611
 612	buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 613	if (!buffer)
 614		return -ENOMEM;
 615
 616	rv = usb_control_msg(data->usb_dev,
 617			     usb_rcvctrlpipe(data->usb_dev, 0),
 618			     USBTMC_REQUEST_INITIATE_CLEAR,
 619			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 620			     0, 0, buffer, 1, USBTMC_TIMEOUT);
 621	if (rv < 0) {
 622		dev_err(dev, "usb_control_msg returned %d\n", rv);
 623		goto exit;
 624	}
 625
 626	dev_dbg(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 627
 628	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 629		dev_err(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 630		rv = -EPERM;
 631		goto exit;
 632	}
 633
 634	max_size = 0;
 635	current_setting = data->intf->cur_altsetting;
 636	for (n = 0; n < current_setting->desc.bNumEndpoints; n++) {
 637		desc = &current_setting->endpoint[n].desc;
 638		if (desc->bEndpointAddress == data->bulk_in)
 639			max_size = le16_to_cpu(desc->wMaxPacketSize);
 640	}
 641
 642	if (max_size == 0) {
 643		dev_err(dev, "Couldn't get wMaxPacketSize\n");
 644		rv = -EPERM;
 645		goto exit;
 646	}
 647
 648	dev_dbg(dev, "wMaxPacketSize is %d\n", max_size);
 649
 650	n = 0;
 651
 652usbtmc_clear_check_status:
 653
 654	dev_dbg(dev, "Sending CHECK_CLEAR_STATUS request\n");
 655
 656	rv = usb_control_msg(data->usb_dev,
 657			     usb_rcvctrlpipe(data->usb_dev, 0),
 658			     USBTMC_REQUEST_CHECK_CLEAR_STATUS,
 659			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 660			     0, 0, buffer, 2, USBTMC_TIMEOUT);
 661	if (rv < 0) {
 662		dev_err(dev, "usb_control_msg returned %d\n", rv);
 663		goto exit;
 664	}
 665
 666	dev_dbg(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 667
 668	if (buffer[0] == USBTMC_STATUS_SUCCESS)
 669		goto usbtmc_clear_bulk_out_halt;
 670
 671	if (buffer[0] != USBTMC_STATUS_PENDING) {
 672		dev_err(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 673		rv = -EPERM;
 674		goto exit;
 675	}
 676
 677	if (buffer[1] == 1)
 678		do {
 679			dev_dbg(dev, "Reading from bulk in EP\n");
 680
 681			rv = usb_bulk_msg(data->usb_dev,
 682					  usb_rcvbulkpipe(data->usb_dev,
 683							  data->bulk_in),
 684					  buffer, USBTMC_SIZE_IOBUFFER,
 685					  &actual, USBTMC_TIMEOUT);
 686			n++;
 687
 688			if (rv < 0) {
 689				dev_err(dev, "usb_control_msg returned %d\n",
 690					rv);
 691				goto exit;
 692			}
 693		} while ((actual == max_size) &&
 694			  (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 695
 696	if (actual == max_size) {
 697		dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 698			USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 699		rv = -EPERM;
 700		goto exit;
 701	}
 702
 703	goto usbtmc_clear_check_status;
 704
 705usbtmc_clear_bulk_out_halt:
 706
 707	rv = usb_clear_halt(data->usb_dev,
 708			    usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 709	if (rv < 0) {
 710		dev_err(dev, "usb_control_msg returned %d\n", rv);
 711		goto exit;
 712	}
 713	rv = 0;
 714
 715exit:
 716	kfree(buffer);
 717	return rv;
 718}
 719
 720static int usbtmc_ioctl_clear_out_halt(struct usbtmc_device_data *data)
 721{
 722	u8 *buffer;
 723	int rv;
 724
 725	buffer = kmalloc(2, GFP_KERNEL);
 726	if (!buffer)
 727		return -ENOMEM;
 728
 729	rv = usb_clear_halt(data->usb_dev,
 730			    usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 731
 732	if (rv < 0) {
 733		dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 734			rv);
 735		goto exit;
 736	}
 737	rv = 0;
 738
 739exit:
 740	kfree(buffer);
 741	return rv;
 742}
 743
 744static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data)
 745{
 746	u8 *buffer;
 747	int rv;
 748
 749	buffer = kmalloc(2, GFP_KERNEL);
 750	if (!buffer)
 751		return -ENOMEM;
 752
 753	rv = usb_clear_halt(data->usb_dev,
 754			    usb_rcvbulkpipe(data->usb_dev, data->bulk_in));
 755
 756	if (rv < 0) {
 757		dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 758			rv);
 759		goto exit;
 760	}
 761	rv = 0;
 762
 763exit:
 764	kfree(buffer);
 765	return rv;
 766}
 767
 768static int get_capabilities(struct usbtmc_device_data *data)
 769{
 770	struct device *dev = &data->usb_dev->dev;
 771	char *buffer;
 772	int rv = 0;
 773
 774	buffer = kmalloc(0x18, GFP_KERNEL);
 775	if (!buffer)
 776		return -ENOMEM;
 777
 778	rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0),
 779			     USBTMC_REQUEST_GET_CAPABILITIES,
 780			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 781			     0, 0, buffer, 0x18, USBTMC_TIMEOUT);
 782	if (rv < 0) {
 783		dev_err(dev, "usb_control_msg returned %d\n", rv);
 784		goto err_out;
 785	}
 786
 787	dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 788	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 789		dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 790		rv = -EPERM;
 791		goto err_out;
 792	}
 793	dev_dbg(dev, "Interface capabilities are %x\n", buffer[4]);
 794	dev_dbg(dev, "Device capabilities are %x\n", buffer[5]);
 795	dev_dbg(dev, "USB488 interface capabilities are %x\n", buffer[14]);
 796	dev_dbg(dev, "USB488 device capabilities are %x\n", buffer[15]);
 797
 798	data->capabilities.interface_capabilities = buffer[4];
 799	data->capabilities.device_capabilities = buffer[5];
 800	data->capabilities.usb488_interface_capabilities = buffer[14];
 801	data->capabilities.usb488_device_capabilities = buffer[15];
 802	rv = 0;
 803
 804err_out:
 805	kfree(buffer);
 806	return rv;
 807}
 808
 809#define capability_attribute(name)					\
 810static ssize_t show_##name(struct device *dev,				\
 811			   struct device_attribute *attr, char *buf)	\
 812{									\
 813	struct usb_interface *intf = to_usb_interface(dev);		\
 814	struct usbtmc_device_data *data = usb_get_intfdata(intf);	\
 815									\
 816	return sprintf(buf, "%d\n", data->capabilities.name);		\
 817}									\
 818static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
 819
 820capability_attribute(interface_capabilities);
 821capability_attribute(device_capabilities);
 822capability_attribute(usb488_interface_capabilities);
 823capability_attribute(usb488_device_capabilities);
 824
 825static struct attribute *capability_attrs[] = {
 826	&dev_attr_interface_capabilities.attr,
 827	&dev_attr_device_capabilities.attr,
 828	&dev_attr_usb488_interface_capabilities.attr,
 829	&dev_attr_usb488_device_capabilities.attr,
 830	NULL,
 831};
 832
 833static struct attribute_group capability_attr_grp = {
 834	.attrs = capability_attrs,
 835};
 836
 837static ssize_t show_TermChar(struct device *dev,
 838			     struct device_attribute *attr, char *buf)
 839{
 840	struct usb_interface *intf = to_usb_interface(dev);
 841	struct usbtmc_device_data *data = usb_get_intfdata(intf);
 842
 843	return sprintf(buf, "%c\n", data->TermChar);
 844}
 845
 846static ssize_t store_TermChar(struct device *dev,
 847			      struct device_attribute *attr,
 848			      const char *buf, size_t count)
 849{
 850	struct usb_interface *intf = to_usb_interface(dev);
 851	struct usbtmc_device_data *data = usb_get_intfdata(intf);
 852
 853	if (count < 1)
 854		return -EINVAL;
 855	data->TermChar = buf[0];
 856	return count;
 857}
 858static DEVICE_ATTR(TermChar, S_IRUGO, show_TermChar, store_TermChar);
 859
 860#define data_attribute(name)						\
 861static ssize_t show_##name(struct device *dev,				\
 862			   struct device_attribute *attr, char *buf)	\
 863{									\
 864	struct usb_interface *intf = to_usb_interface(dev);		\
 865	struct usbtmc_device_data *data = usb_get_intfdata(intf);	\
 866									\
 867	return sprintf(buf, "%d\n", data->name);			\
 868}									\
 869static ssize_t store_##name(struct device *dev,				\
 870			    struct device_attribute *attr,		\
 871			    const char *buf, size_t count)		\
 872{									\
 873	struct usb_interface *intf = to_usb_interface(dev);		\
 874	struct usbtmc_device_data *data = usb_get_intfdata(intf);	\
 875	ssize_t result;							\
 876	unsigned val;							\
 877									\
 878	result = sscanf(buf, "%u\n", &val);				\
 879	if (result != 1)						\
 880		result = -EINVAL;					\
 881	data->name = val;						\
 882	if (result < 0)							\
 883		return result;						\
 884	else								\
 885		return count;						\
 886}									\
 887static DEVICE_ATTR(name, S_IRUGO, show_##name, store_##name)
 888
 889data_attribute(TermCharEnabled);
 890data_attribute(auto_abort);
 891
 892static struct attribute *data_attrs[] = {
 893	&dev_attr_TermChar.attr,
 894	&dev_attr_TermCharEnabled.attr,
 895	&dev_attr_auto_abort.attr,
 896	NULL,
 897};
 898
 899static struct attribute_group data_attr_grp = {
 900	.attrs = data_attrs,
 901};
 902
 903static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
 904{
 905	struct device *dev;
 906	u8 *buffer;
 907	int rv;
 908
 909	dev = &data->intf->dev;
 910
 911	buffer = kmalloc(2, GFP_KERNEL);
 912	if (!buffer)
 913		return -ENOMEM;
 914
 915	rv = usb_control_msg(data->usb_dev,
 916			     usb_rcvctrlpipe(data->usb_dev, 0),
 917			     USBTMC_REQUEST_INDICATOR_PULSE,
 918			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 919			     0, 0, buffer, 0x01, USBTMC_TIMEOUT);
 920
 921	if (rv < 0) {
 922		dev_err(dev, "usb_control_msg returned %d\n", rv);
 923		goto exit;
 924	}
 925
 926	dev_dbg(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
 927
 928	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 929		dev_err(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
 930		rv = -EPERM;
 931		goto exit;
 932	}
 933	rv = 0;
 934
 935exit:
 936	kfree(buffer);
 937	return rv;
 938}
 939
 940static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 941{
 942	struct usbtmc_device_data *data;
 943	int retval = -EBADRQC;
 944
 945	data = file->private_data;
 946	mutex_lock(&data->io_mutex);
 947	if (data->zombie) {
 948		retval = -ENODEV;
 949		goto skip_io_on_zombie;
 950	}
 951
 952	switch (cmd) {
 953	case USBTMC_IOCTL_CLEAR_OUT_HALT:
 954		retval = usbtmc_ioctl_clear_out_halt(data);
 955		break;
 956
 957	case USBTMC_IOCTL_CLEAR_IN_HALT:
 958		retval = usbtmc_ioctl_clear_in_halt(data);
 959		break;
 960
 961	case USBTMC_IOCTL_INDICATOR_PULSE:
 962		retval = usbtmc_ioctl_indicator_pulse(data);
 963		break;
 964
 965	case USBTMC_IOCTL_CLEAR:
 966		retval = usbtmc_ioctl_clear(data);
 967		break;
 968
 969	case USBTMC_IOCTL_ABORT_BULK_OUT:
 970		retval = usbtmc_ioctl_abort_bulk_out(data);
 971		break;
 972
 973	case USBTMC_IOCTL_ABORT_BULK_IN:
 974		retval = usbtmc_ioctl_abort_bulk_in(data);
 975		break;
 976	}
 977
 978skip_io_on_zombie:
 979	mutex_unlock(&data->io_mutex);
 980	return retval;
 981}
 982
 983static const struct file_operations fops = {
 984	.owner		= THIS_MODULE,
 985	.read		= usbtmc_read,
 986	.write		= usbtmc_write,
 987	.open		= usbtmc_open,
 988	.release	= usbtmc_release,
 989	.unlocked_ioctl	= usbtmc_ioctl,
 990	.llseek		= default_llseek,
 991};
 992
 993static struct usb_class_driver usbtmc_class = {
 994	.name =		"usbtmc%d",
 995	.fops =		&fops,
 996	.minor_base =	USBTMC_MINOR_BASE,
 997};
 998
 999
1000static int usbtmc_probe(struct usb_interface *intf,
1001			const struct usb_device_id *id)
1002{
1003	struct usbtmc_device_data *data;
1004	struct usb_host_interface *iface_desc;
1005	struct usb_endpoint_descriptor *endpoint;
1006	int n;
1007	int retcode;
1008
1009	dev_dbg(&intf->dev, "%s called\n", __func__);
1010
1011	data = kmalloc(sizeof(struct usbtmc_device_data), GFP_KERNEL);
1012	if (!data) {
1013		dev_err(&intf->dev, "Unable to allocate kernel memory\n");
1014		return -ENOMEM;
1015	}
1016
1017	data->intf = intf;
1018	data->id = id;
1019	data->usb_dev = usb_get_dev(interface_to_usbdev(intf));
1020	usb_set_intfdata(intf, data);
1021	kref_init(&data->kref);
1022	mutex_init(&data->io_mutex);
1023	data->zombie = 0;
1024
1025	/* Initialize USBTMC bTag and other fields */
1026	data->bTag	= 1;
1027	data->TermCharEnabled = 0;
1028	data->TermChar = '\n';
1029
1030	/* USBTMC devices have only one setting, so use that */
1031	iface_desc = data->intf->cur_altsetting;
1032
1033	/* Find bulk in endpoint */
1034	for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1035		endpoint = &iface_desc->endpoint[n].desc;
1036
1037		if (usb_endpoint_is_bulk_in(endpoint)) {
1038			data->bulk_in = endpoint->bEndpointAddress;
1039			dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n",
1040				data->bulk_in);
1041			break;
1042		}
1043	}
1044
1045	/* Find bulk out endpoint */
1046	for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1047		endpoint = &iface_desc->endpoint[n].desc;
1048
1049		if (usb_endpoint_is_bulk_out(endpoint)) {
1050			data->bulk_out = endpoint->bEndpointAddress;
1051			dev_dbg(&intf->dev, "Found Bulk out endpoint at %u\n",
1052				data->bulk_out);
1053			break;
1054		}
1055	}
1056
1057	retcode = get_capabilities(data);
1058	if (retcode)
1059		dev_err(&intf->dev, "can't read capabilities\n");
1060	else
1061		retcode = sysfs_create_group(&intf->dev.kobj,
1062					     &capability_attr_grp);
1063
1064	retcode = sysfs_create_group(&intf->dev.kobj, &data_attr_grp);
1065
1066	retcode = usb_register_dev(intf, &usbtmc_class);
1067	if (retcode) {
1068		dev_err(&intf->dev, "Not able to get a minor"
1069			" (base %u, slice default): %d\n", USBTMC_MINOR_BASE,
1070			retcode);
1071		goto error_register;
1072	}
1073	dev_dbg(&intf->dev, "Using minor number %d\n", intf->minor);
1074
1075	return 0;
1076
1077error_register:
1078	sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1079	sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1080	kref_put(&data->kref, usbtmc_delete);
1081	return retcode;
1082}
1083
1084static void usbtmc_disconnect(struct usb_interface *intf)
1085{
1086	struct usbtmc_device_data *data;
1087
1088	dev_dbg(&intf->dev, "usbtmc_disconnect called\n");
1089
1090	data = usb_get_intfdata(intf);
1091	usb_deregister_dev(intf, &usbtmc_class);
1092	sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1093	sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1094	mutex_lock(&data->io_mutex);
1095	data->zombie = 1;
1096	mutex_unlock(&data->io_mutex);
1097	kref_put(&data->kref, usbtmc_delete);
1098}
1099
1100static int usbtmc_suspend(struct usb_interface *intf, pm_message_t message)
1101{
1102	/* this driver does not have pending URBs */
1103	return 0;
1104}
1105
1106static int usbtmc_resume(struct usb_interface *intf)
1107{
1108	return 0;
1109}
1110
1111static struct usb_driver usbtmc_driver = {
1112	.name		= "usbtmc",
1113	.id_table	= usbtmc_devices,
1114	.probe		= usbtmc_probe,
1115	.disconnect	= usbtmc_disconnect,
1116	.suspend	= usbtmc_suspend,
1117	.resume		= usbtmc_resume,
1118};
1119
1120static int __init usbtmc_init(void)
1121{
1122	int retcode;
1123
1124	retcode = usb_register(&usbtmc_driver);
1125	if (retcode)
1126		printk(KERN_ERR KBUILD_MODNAME": Unable to register driver\n");
1127	return retcode;
1128}
1129module_init(usbtmc_init);
1130
1131static void __exit usbtmc_exit(void)
1132{
1133	usb_deregister(&usbtmc_driver);
1134}
1135module_exit(usbtmc_exit);
1136
1137MODULE_LICENSE("GPL");
v3.5.6
   1/**
   2 * drivers/usb/class/usbtmc.c - USB Test & Measurement class driver
   3 *
   4 * Copyright (C) 2007 Stefan Kopp, Gechingen, Germany
   5 * Copyright (C) 2008 Novell, Inc.
   6 * Copyright (C) 2008 Greg Kroah-Hartman <gregkh@suse.de>
   7 *
   8 * This program is free software; you can redistribute it and/or
   9 * modify it under the terms of the GNU General Public License
  10 * as published by the Free Software Foundation; either version 2
  11 * of the License, or (at your option) any later version.
  12 *
  13 * This program is distributed in the hope that it will be useful,
  14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 * GNU General Public License for more details.
  17 *
  18 * The GNU General Public License is available at
  19 * http://www.gnu.org/copyleft/gpl.html.
  20 */
  21
  22#include <linux/init.h>
  23#include <linux/module.h>
  24#include <linux/kernel.h>
  25#include <linux/fs.h>
  26#include <linux/uaccess.h>
  27#include <linux/kref.h>
  28#include <linux/slab.h>
  29#include <linux/mutex.h>
  30#include <linux/usb.h>
  31#include <linux/usb/tmc.h>
  32
  33
  34#define USBTMC_MINOR_BASE	176
  35
  36/*
  37 * Size of driver internal IO buffer. Must be multiple of 4 and at least as
  38 * large as wMaxPacketSize (which is usually 512 bytes).
  39 */
  40#define USBTMC_SIZE_IOBUFFER	2048
  41
  42/* Default USB timeout (in milliseconds) */
  43#define USBTMC_TIMEOUT		5000
  44
  45/*
  46 * Maximum number of read cycles to empty bulk in endpoint during CLEAR and
  47 * ABORT_BULK_IN requests. Ends the loop if (for whatever reason) a short
  48 * packet is never read.
  49 */
  50#define USBTMC_MAX_READS_TO_CLEAR_BULK_IN	100
  51
  52static const struct usb_device_id usbtmc_devices[] = {
  53	{ USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 0), },
  54	{ USB_INTERFACE_INFO(USB_CLASS_APP_SPEC, 3, 1), },
  55	{ 0, } /* terminating entry */
  56};
  57MODULE_DEVICE_TABLE(usb, usbtmc_devices);
  58
  59/*
  60 * This structure is the capabilities for the device
  61 * See section 4.2.1.8 of the USBTMC specification,
  62 * and section 4.2.2 of the USBTMC usb488 subclass
  63 * specification for details.
  64 */
  65struct usbtmc_dev_capabilities {
  66	__u8 interface_capabilities;
  67	__u8 device_capabilities;
  68	__u8 usb488_interface_capabilities;
  69	__u8 usb488_device_capabilities;
  70};
  71
  72/* This structure holds private data for each USBTMC device. One copy is
  73 * allocated for each USBTMC device in the driver's probe function.
  74 */
  75struct usbtmc_device_data {
  76	const struct usb_device_id *id;
  77	struct usb_device *usb_dev;
  78	struct usb_interface *intf;
  79
  80	unsigned int bulk_in;
  81	unsigned int bulk_out;
  82
  83	u8 bTag;
  84	u8 bTag_last_write;	/* needed for abort */
  85	u8 bTag_last_read;	/* needed for abort */
  86
  87	/* attributes from the USB TMC spec for this device */
  88	u8 TermChar;
  89	bool TermCharEnabled;
  90	bool auto_abort;
  91
  92	bool zombie; /* fd of disconnected device */
  93
  94	struct usbtmc_dev_capabilities	capabilities;
  95	struct kref kref;
  96	struct mutex io_mutex;	/* only one i/o function running at a time */
  97};
  98#define to_usbtmc_data(d) container_of(d, struct usbtmc_device_data, kref)
  99
 100/* Forward declarations */
 101static struct usb_driver usbtmc_driver;
 102
 103static void usbtmc_delete(struct kref *kref)
 104{
 105	struct usbtmc_device_data *data = to_usbtmc_data(kref);
 106
 107	usb_put_dev(data->usb_dev);
 108	kfree(data);
 109}
 110
 111static int usbtmc_open(struct inode *inode, struct file *filp)
 112{
 113	struct usb_interface *intf;
 114	struct usbtmc_device_data *data;
 115	int retval = 0;
 116
 117	intf = usb_find_interface(&usbtmc_driver, iminor(inode));
 118	if (!intf) {
 119		printk(KERN_ERR KBUILD_MODNAME
 120		       ": can not find device for minor %d", iminor(inode));
 121		retval = -ENODEV;
 122		goto exit;
 123	}
 124
 125	data = usb_get_intfdata(intf);
 126	kref_get(&data->kref);
 127
 128	/* Store pointer in file structure's private data field */
 129	filp->private_data = data;
 130
 131exit:
 132	return retval;
 133}
 134
 135static int usbtmc_release(struct inode *inode, struct file *file)
 136{
 137	struct usbtmc_device_data *data = file->private_data;
 138
 139	kref_put(&data->kref, usbtmc_delete);
 140	return 0;
 141}
 142
 143static int usbtmc_ioctl_abort_bulk_in(struct usbtmc_device_data *data)
 144{
 145	u8 *buffer;
 146	struct device *dev;
 147	int rv;
 148	int n;
 149	int actual;
 150	struct usb_host_interface *current_setting;
 151	int max_size;
 152
 153	dev = &data->intf->dev;
 154	buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 155	if (!buffer)
 156		return -ENOMEM;
 157
 158	rv = usb_control_msg(data->usb_dev,
 159			     usb_rcvctrlpipe(data->usb_dev, 0),
 160			     USBTMC_REQUEST_INITIATE_ABORT_BULK_IN,
 161			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 162			     data->bTag_last_read, data->bulk_in,
 163			     buffer, 2, USBTMC_TIMEOUT);
 164
 165	if (rv < 0) {
 166		dev_err(dev, "usb_control_msg returned %d\n", rv);
 167		goto exit;
 168	}
 169
 170	dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 171
 172	if (buffer[0] == USBTMC_STATUS_FAILED) {
 173		rv = 0;
 174		goto exit;
 175	}
 176
 177	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 178		dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n",
 179			buffer[0]);
 180		rv = -EPERM;
 181		goto exit;
 182	}
 183
 184	max_size = 0;
 185	current_setting = data->intf->cur_altsetting;
 186	for (n = 0; n < current_setting->desc.bNumEndpoints; n++)
 187		if (current_setting->endpoint[n].desc.bEndpointAddress ==
 188			data->bulk_in)
 189			max_size = usb_endpoint_maxp(&current_setting->endpoint[n].desc);
 
 190
 191	if (max_size == 0) {
 192		dev_err(dev, "Couldn't get wMaxPacketSize\n");
 193		rv = -EPERM;
 194		goto exit;
 195	}
 196
 197	dev_dbg(&data->intf->dev, "wMaxPacketSize is %d\n", max_size);
 198
 199	n = 0;
 200
 201	do {
 202		dev_dbg(dev, "Reading from bulk in EP\n");
 203
 204		rv = usb_bulk_msg(data->usb_dev,
 205				  usb_rcvbulkpipe(data->usb_dev,
 206						  data->bulk_in),
 207				  buffer, USBTMC_SIZE_IOBUFFER,
 208				  &actual, USBTMC_TIMEOUT);
 209
 210		n++;
 211
 212		if (rv < 0) {
 213			dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 214			goto exit;
 215		}
 216	} while ((actual == max_size) &&
 217		 (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 218
 219	if (actual == max_size) {
 220		dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 221			USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 222		rv = -EPERM;
 223		goto exit;
 224	}
 225
 226	n = 0;
 227
 228usbtmc_abort_bulk_in_status:
 229	rv = usb_control_msg(data->usb_dev,
 230			     usb_rcvctrlpipe(data->usb_dev, 0),
 231			     USBTMC_REQUEST_CHECK_ABORT_BULK_IN_STATUS,
 232			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 233			     0, data->bulk_in, buffer, 0x08,
 234			     USBTMC_TIMEOUT);
 235
 236	if (rv < 0) {
 237		dev_err(dev, "usb_control_msg returned %d\n", rv);
 238		goto exit;
 239	}
 240
 241	dev_dbg(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 242
 243	if (buffer[0] == USBTMC_STATUS_SUCCESS) {
 244		rv = 0;
 245		goto exit;
 246	}
 247
 248	if (buffer[0] != USBTMC_STATUS_PENDING) {
 249		dev_err(dev, "INITIATE_ABORT_BULK_IN returned %x\n", buffer[0]);
 250		rv = -EPERM;
 251		goto exit;
 252	}
 253
 254	if (buffer[1] == 1)
 255		do {
 256			dev_dbg(dev, "Reading from bulk in EP\n");
 257
 258			rv = usb_bulk_msg(data->usb_dev,
 259					  usb_rcvbulkpipe(data->usb_dev,
 260							  data->bulk_in),
 261					  buffer, USBTMC_SIZE_IOBUFFER,
 262					  &actual, USBTMC_TIMEOUT);
 263
 264			n++;
 265
 266			if (rv < 0) {
 267				dev_err(dev, "usb_bulk_msg returned %d\n", rv);
 268				goto exit;
 269			}
 270		} while ((actual == max_size) &&
 271			 (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 272
 273	if (actual == max_size) {
 274		dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 275			USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 276		rv = -EPERM;
 277		goto exit;
 278	}
 279
 280	goto usbtmc_abort_bulk_in_status;
 281
 282exit:
 283	kfree(buffer);
 284	return rv;
 285
 286}
 287
 288static int usbtmc_ioctl_abort_bulk_out(struct usbtmc_device_data *data)
 289{
 290	struct device *dev;
 291	u8 *buffer;
 292	int rv;
 293	int n;
 294
 295	dev = &data->intf->dev;
 296
 297	buffer = kmalloc(8, GFP_KERNEL);
 298	if (!buffer)
 299		return -ENOMEM;
 300
 301	rv = usb_control_msg(data->usb_dev,
 302			     usb_rcvctrlpipe(data->usb_dev, 0),
 303			     USBTMC_REQUEST_INITIATE_ABORT_BULK_OUT,
 304			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 305			     data->bTag_last_write, data->bulk_out,
 306			     buffer, 2, USBTMC_TIMEOUT);
 307
 308	if (rv < 0) {
 309		dev_err(dev, "usb_control_msg returned %d\n", rv);
 310		goto exit;
 311	}
 312
 313	dev_dbg(dev, "INITIATE_ABORT_BULK_OUT returned %x\n", buffer[0]);
 314
 315	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 316		dev_err(dev, "INITIATE_ABORT_BULK_OUT returned %x\n",
 317			buffer[0]);
 318		rv = -EPERM;
 319		goto exit;
 320	}
 321
 322	n = 0;
 323
 324usbtmc_abort_bulk_out_check_status:
 325	rv = usb_control_msg(data->usb_dev,
 326			     usb_rcvctrlpipe(data->usb_dev, 0),
 327			     USBTMC_REQUEST_CHECK_ABORT_BULK_OUT_STATUS,
 328			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_ENDPOINT,
 329			     0, data->bulk_out, buffer, 0x08,
 330			     USBTMC_TIMEOUT);
 331	n++;
 332	if (rv < 0) {
 333		dev_err(dev, "usb_control_msg returned %d\n", rv);
 334		goto exit;
 335	}
 336
 337	dev_dbg(dev, "CHECK_ABORT_BULK_OUT returned %x\n", buffer[0]);
 338
 339	if (buffer[0] == USBTMC_STATUS_SUCCESS)
 340		goto usbtmc_abort_bulk_out_clear_halt;
 341
 342	if ((buffer[0] == USBTMC_STATUS_PENDING) &&
 343	    (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN))
 344		goto usbtmc_abort_bulk_out_check_status;
 345
 346	rv = -EPERM;
 347	goto exit;
 348
 349usbtmc_abort_bulk_out_clear_halt:
 350	rv = usb_clear_halt(data->usb_dev,
 351			    usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 352
 353	if (rv < 0) {
 354		dev_err(dev, "usb_control_msg returned %d\n", rv);
 355		goto exit;
 356	}
 357	rv = 0;
 358
 359exit:
 360	kfree(buffer);
 361	return rv;
 362}
 363
 364static ssize_t usbtmc_read(struct file *filp, char __user *buf,
 365			   size_t count, loff_t *f_pos)
 366{
 367	struct usbtmc_device_data *data;
 368	struct device *dev;
 369	u32 n_characters;
 370	u8 *buffer;
 371	int actual;
 372	size_t done;
 373	size_t remaining;
 374	int retval;
 375	size_t this_part;
 376
 377	/* Get pointer to private data structure */
 378	data = filp->private_data;
 379	dev = &data->intf->dev;
 380
 381	buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 382	if (!buffer)
 383		return -ENOMEM;
 384
 385	mutex_lock(&data->io_mutex);
 386	if (data->zombie) {
 387		retval = -ENODEV;
 388		goto exit;
 389	}
 390
 391	remaining = count;
 392	done = 0;
 393
 394	while (remaining > 0) {
 395		if (remaining > USBTMC_SIZE_IOBUFFER - 12 - 3)
 396			this_part = USBTMC_SIZE_IOBUFFER - 12 - 3;
 397		else
 398			this_part = remaining;
 399
 400		/* Setup IO buffer for DEV_DEP_MSG_IN message
 401		 * Refer to class specs for details
 402		 */
 403		buffer[0] = 2;
 404		buffer[1] = data->bTag;
 405		buffer[2] = ~(data->bTag);
 406		buffer[3] = 0; /* Reserved */
 407		buffer[4] = (this_part) & 255;
 408		buffer[5] = ((this_part) >> 8) & 255;
 409		buffer[6] = ((this_part) >> 16) & 255;
 410		buffer[7] = ((this_part) >> 24) & 255;
 411		buffer[8] = data->TermCharEnabled * 2;
 412		/* Use term character? */
 413		buffer[9] = data->TermChar;
 414		buffer[10] = 0; /* Reserved */
 415		buffer[11] = 0; /* Reserved */
 416
 417		/* Send bulk URB */
 418		retval = usb_bulk_msg(data->usb_dev,
 419				      usb_sndbulkpipe(data->usb_dev,
 420						      data->bulk_out),
 421				      buffer, 12, &actual, USBTMC_TIMEOUT);
 422
 423		/* Store bTag (in case we need to abort) */
 424		data->bTag_last_write = data->bTag;
 425
 426		/* Increment bTag -- and increment again if zero */
 427		data->bTag++;
 428		if (!data->bTag)
 429			(data->bTag)++;
 430
 431		if (retval < 0) {
 432			dev_err(dev, "usb_bulk_msg returned %d\n", retval);
 433			if (data->auto_abort)
 434				usbtmc_ioctl_abort_bulk_out(data);
 435			goto exit;
 436		}
 437
 438		/* Send bulk URB */
 439		retval = usb_bulk_msg(data->usb_dev,
 440				      usb_rcvbulkpipe(data->usb_dev,
 441						      data->bulk_in),
 442				      buffer, USBTMC_SIZE_IOBUFFER, &actual,
 443				      USBTMC_TIMEOUT);
 444
 445		/* Store bTag (in case we need to abort) */
 446		data->bTag_last_read = data->bTag;
 447
 448		if (retval < 0) {
 449			dev_err(dev, "Unable to read data, error %d\n", retval);
 450			if (data->auto_abort)
 451				usbtmc_ioctl_abort_bulk_in(data);
 452			goto exit;
 453		}
 454
 455		/* How many characters did the instrument send? */
 456		n_characters = buffer[4] +
 457			       (buffer[5] << 8) +
 458			       (buffer[6] << 16) +
 459			       (buffer[7] << 24);
 460
 461		/* Ensure the instrument doesn't lie about it */
 462		if(n_characters > actual - 12) {
 463			dev_err(dev, "Device lies about message size: %u > %d\n", n_characters, actual - 12);
 464			n_characters = actual - 12;
 465		}
 466
 467		/* Ensure the instrument doesn't send more back than requested */
 468		if(n_characters > this_part) {
 469			dev_err(dev, "Device returns more than requested: %zu > %zu\n", done + n_characters, done + this_part);
 470			n_characters = this_part;
 471		}
 472
 473		/* Bound amount of data received by amount of data requested */
 474		if (n_characters > this_part)
 475			n_characters = this_part;
 476
 477		/* Copy buffer to user space */
 478		if (copy_to_user(buf + done, &buffer[12], n_characters)) {
 479			/* There must have been an addressing problem */
 480			retval = -EFAULT;
 481			goto exit;
 482		}
 483
 484		done += n_characters;
 485		/* Terminate if end-of-message bit received from device */
 486		if ((buffer[8] &  0x01) && (actual >= n_characters + 12))
 487			remaining = 0;
 488		else
 489			remaining -= n_characters;
 490	}
 491
 492	/* Update file position value */
 493	*f_pos = *f_pos + done;
 494	retval = done;
 495
 496exit:
 497	mutex_unlock(&data->io_mutex);
 498	kfree(buffer);
 499	return retval;
 500}
 501
 502static ssize_t usbtmc_write(struct file *filp, const char __user *buf,
 503			    size_t count, loff_t *f_pos)
 504{
 505	struct usbtmc_device_data *data;
 506	u8 *buffer;
 507	int retval;
 508	int actual;
 509	unsigned long int n_bytes;
 510	int remaining;
 511	int done;
 512	int this_part;
 513
 514	data = filp->private_data;
 515
 516	buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 517	if (!buffer)
 518		return -ENOMEM;
 519
 520	mutex_lock(&data->io_mutex);
 521	if (data->zombie) {
 522		retval = -ENODEV;
 523		goto exit;
 524	}
 525
 526	remaining = count;
 527	done = 0;
 528
 529	while (remaining > 0) {
 530		if (remaining > USBTMC_SIZE_IOBUFFER - 12) {
 531			this_part = USBTMC_SIZE_IOBUFFER - 12;
 532			buffer[8] = 0;
 533		} else {
 534			this_part = remaining;
 535			buffer[8] = 1;
 536		}
 537
 538		/* Setup IO buffer for DEV_DEP_MSG_OUT message */
 539		buffer[0] = 1;
 540		buffer[1] = data->bTag;
 541		buffer[2] = ~(data->bTag);
 542		buffer[3] = 0; /* Reserved */
 543		buffer[4] = this_part & 255;
 544		buffer[5] = (this_part >> 8) & 255;
 545		buffer[6] = (this_part >> 16) & 255;
 546		buffer[7] = (this_part >> 24) & 255;
 547		/* buffer[8] is set above... */
 548		buffer[9] = 0; /* Reserved */
 549		buffer[10] = 0; /* Reserved */
 550		buffer[11] = 0; /* Reserved */
 551
 552		if (copy_from_user(&buffer[12], buf + done, this_part)) {
 553			retval = -EFAULT;
 554			goto exit;
 555		}
 556
 557		n_bytes = roundup(12 + this_part, 4);
 558		memset(buffer + 12 + this_part, 0, n_bytes - (12 + this_part));
 559
 560		do {
 561			retval = usb_bulk_msg(data->usb_dev,
 562					      usb_sndbulkpipe(data->usb_dev,
 563							      data->bulk_out),
 564					      buffer, n_bytes,
 565					      &actual, USBTMC_TIMEOUT);
 566			if (retval != 0)
 567				break;
 568			n_bytes -= actual;
 569		} while (n_bytes);
 570
 571		data->bTag_last_write = data->bTag;
 572		data->bTag++;
 573
 574		if (!data->bTag)
 575			data->bTag++;
 576
 577		if (retval < 0) {
 578			dev_err(&data->intf->dev,
 579				"Unable to send data, error %d\n", retval);
 580			if (data->auto_abort)
 581				usbtmc_ioctl_abort_bulk_out(data);
 582			goto exit;
 583		}
 584
 585		remaining -= this_part;
 586		done += this_part;
 587	}
 588
 589	retval = count;
 590exit:
 591	mutex_unlock(&data->io_mutex);
 592	kfree(buffer);
 593	return retval;
 594}
 595
 596static int usbtmc_ioctl_clear(struct usbtmc_device_data *data)
 597{
 598	struct usb_host_interface *current_setting;
 599	struct usb_endpoint_descriptor *desc;
 600	struct device *dev;
 601	u8 *buffer;
 602	int rv;
 603	int n;
 604	int actual;
 605	int max_size;
 606
 607	dev = &data->intf->dev;
 608
 609	dev_dbg(dev, "Sending INITIATE_CLEAR request\n");
 610
 611	buffer = kmalloc(USBTMC_SIZE_IOBUFFER, GFP_KERNEL);
 612	if (!buffer)
 613		return -ENOMEM;
 614
 615	rv = usb_control_msg(data->usb_dev,
 616			     usb_rcvctrlpipe(data->usb_dev, 0),
 617			     USBTMC_REQUEST_INITIATE_CLEAR,
 618			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 619			     0, 0, buffer, 1, USBTMC_TIMEOUT);
 620	if (rv < 0) {
 621		dev_err(dev, "usb_control_msg returned %d\n", rv);
 622		goto exit;
 623	}
 624
 625	dev_dbg(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 626
 627	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 628		dev_err(dev, "INITIATE_CLEAR returned %x\n", buffer[0]);
 629		rv = -EPERM;
 630		goto exit;
 631	}
 632
 633	max_size = 0;
 634	current_setting = data->intf->cur_altsetting;
 635	for (n = 0; n < current_setting->desc.bNumEndpoints; n++) {
 636		desc = &current_setting->endpoint[n].desc;
 637		if (desc->bEndpointAddress == data->bulk_in)
 638			max_size = usb_endpoint_maxp(desc);
 639	}
 640
 641	if (max_size == 0) {
 642		dev_err(dev, "Couldn't get wMaxPacketSize\n");
 643		rv = -EPERM;
 644		goto exit;
 645	}
 646
 647	dev_dbg(dev, "wMaxPacketSize is %d\n", max_size);
 648
 649	n = 0;
 650
 651usbtmc_clear_check_status:
 652
 653	dev_dbg(dev, "Sending CHECK_CLEAR_STATUS request\n");
 654
 655	rv = usb_control_msg(data->usb_dev,
 656			     usb_rcvctrlpipe(data->usb_dev, 0),
 657			     USBTMC_REQUEST_CHECK_CLEAR_STATUS,
 658			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 659			     0, 0, buffer, 2, USBTMC_TIMEOUT);
 660	if (rv < 0) {
 661		dev_err(dev, "usb_control_msg returned %d\n", rv);
 662		goto exit;
 663	}
 664
 665	dev_dbg(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 666
 667	if (buffer[0] == USBTMC_STATUS_SUCCESS)
 668		goto usbtmc_clear_bulk_out_halt;
 669
 670	if (buffer[0] != USBTMC_STATUS_PENDING) {
 671		dev_err(dev, "CHECK_CLEAR_STATUS returned %x\n", buffer[0]);
 672		rv = -EPERM;
 673		goto exit;
 674	}
 675
 676	if (buffer[1] == 1)
 677		do {
 678			dev_dbg(dev, "Reading from bulk in EP\n");
 679
 680			rv = usb_bulk_msg(data->usb_dev,
 681					  usb_rcvbulkpipe(data->usb_dev,
 682							  data->bulk_in),
 683					  buffer, USBTMC_SIZE_IOBUFFER,
 684					  &actual, USBTMC_TIMEOUT);
 685			n++;
 686
 687			if (rv < 0) {
 688				dev_err(dev, "usb_control_msg returned %d\n",
 689					rv);
 690				goto exit;
 691			}
 692		} while ((actual == max_size) &&
 693			  (n < USBTMC_MAX_READS_TO_CLEAR_BULK_IN));
 694
 695	if (actual == max_size) {
 696		dev_err(dev, "Couldn't clear device buffer within %d cycles\n",
 697			USBTMC_MAX_READS_TO_CLEAR_BULK_IN);
 698		rv = -EPERM;
 699		goto exit;
 700	}
 701
 702	goto usbtmc_clear_check_status;
 703
 704usbtmc_clear_bulk_out_halt:
 705
 706	rv = usb_clear_halt(data->usb_dev,
 707			    usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 708	if (rv < 0) {
 709		dev_err(dev, "usb_control_msg returned %d\n", rv);
 710		goto exit;
 711	}
 712	rv = 0;
 713
 714exit:
 715	kfree(buffer);
 716	return rv;
 717}
 718
 719static int usbtmc_ioctl_clear_out_halt(struct usbtmc_device_data *data)
 720{
 721	u8 *buffer;
 722	int rv;
 723
 724	buffer = kmalloc(2, GFP_KERNEL);
 725	if (!buffer)
 726		return -ENOMEM;
 727
 728	rv = usb_clear_halt(data->usb_dev,
 729			    usb_sndbulkpipe(data->usb_dev, data->bulk_out));
 730
 731	if (rv < 0) {
 732		dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 733			rv);
 734		goto exit;
 735	}
 736	rv = 0;
 737
 738exit:
 739	kfree(buffer);
 740	return rv;
 741}
 742
 743static int usbtmc_ioctl_clear_in_halt(struct usbtmc_device_data *data)
 744{
 745	u8 *buffer;
 746	int rv;
 747
 748	buffer = kmalloc(2, GFP_KERNEL);
 749	if (!buffer)
 750		return -ENOMEM;
 751
 752	rv = usb_clear_halt(data->usb_dev,
 753			    usb_rcvbulkpipe(data->usb_dev, data->bulk_in));
 754
 755	if (rv < 0) {
 756		dev_err(&data->usb_dev->dev, "usb_control_msg returned %d\n",
 757			rv);
 758		goto exit;
 759	}
 760	rv = 0;
 761
 762exit:
 763	kfree(buffer);
 764	return rv;
 765}
 766
 767static int get_capabilities(struct usbtmc_device_data *data)
 768{
 769	struct device *dev = &data->usb_dev->dev;
 770	char *buffer;
 771	int rv = 0;
 772
 773	buffer = kmalloc(0x18, GFP_KERNEL);
 774	if (!buffer)
 775		return -ENOMEM;
 776
 777	rv = usb_control_msg(data->usb_dev, usb_rcvctrlpipe(data->usb_dev, 0),
 778			     USBTMC_REQUEST_GET_CAPABILITIES,
 779			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 780			     0, 0, buffer, 0x18, USBTMC_TIMEOUT);
 781	if (rv < 0) {
 782		dev_err(dev, "usb_control_msg returned %d\n", rv);
 783		goto err_out;
 784	}
 785
 786	dev_dbg(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 787	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 788		dev_err(dev, "GET_CAPABILITIES returned %x\n", buffer[0]);
 789		rv = -EPERM;
 790		goto err_out;
 791	}
 792	dev_dbg(dev, "Interface capabilities are %x\n", buffer[4]);
 793	dev_dbg(dev, "Device capabilities are %x\n", buffer[5]);
 794	dev_dbg(dev, "USB488 interface capabilities are %x\n", buffer[14]);
 795	dev_dbg(dev, "USB488 device capabilities are %x\n", buffer[15]);
 796
 797	data->capabilities.interface_capabilities = buffer[4];
 798	data->capabilities.device_capabilities = buffer[5];
 799	data->capabilities.usb488_interface_capabilities = buffer[14];
 800	data->capabilities.usb488_device_capabilities = buffer[15];
 801	rv = 0;
 802
 803err_out:
 804	kfree(buffer);
 805	return rv;
 806}
 807
 808#define capability_attribute(name)					\
 809static ssize_t show_##name(struct device *dev,				\
 810			   struct device_attribute *attr, char *buf)	\
 811{									\
 812	struct usb_interface *intf = to_usb_interface(dev);		\
 813	struct usbtmc_device_data *data = usb_get_intfdata(intf);	\
 814									\
 815	return sprintf(buf, "%d\n", data->capabilities.name);		\
 816}									\
 817static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL)
 818
 819capability_attribute(interface_capabilities);
 820capability_attribute(device_capabilities);
 821capability_attribute(usb488_interface_capabilities);
 822capability_attribute(usb488_device_capabilities);
 823
 824static struct attribute *capability_attrs[] = {
 825	&dev_attr_interface_capabilities.attr,
 826	&dev_attr_device_capabilities.attr,
 827	&dev_attr_usb488_interface_capabilities.attr,
 828	&dev_attr_usb488_device_capabilities.attr,
 829	NULL,
 830};
 831
 832static struct attribute_group capability_attr_grp = {
 833	.attrs = capability_attrs,
 834};
 835
 836static ssize_t show_TermChar(struct device *dev,
 837			     struct device_attribute *attr, char *buf)
 838{
 839	struct usb_interface *intf = to_usb_interface(dev);
 840	struct usbtmc_device_data *data = usb_get_intfdata(intf);
 841
 842	return sprintf(buf, "%c\n", data->TermChar);
 843}
 844
 845static ssize_t store_TermChar(struct device *dev,
 846			      struct device_attribute *attr,
 847			      const char *buf, size_t count)
 848{
 849	struct usb_interface *intf = to_usb_interface(dev);
 850	struct usbtmc_device_data *data = usb_get_intfdata(intf);
 851
 852	if (count < 1)
 853		return -EINVAL;
 854	data->TermChar = buf[0];
 855	return count;
 856}
 857static DEVICE_ATTR(TermChar, S_IRUGO, show_TermChar, store_TermChar);
 858
 859#define data_attribute(name)						\
 860static ssize_t show_##name(struct device *dev,				\
 861			   struct device_attribute *attr, char *buf)	\
 862{									\
 863	struct usb_interface *intf = to_usb_interface(dev);		\
 864	struct usbtmc_device_data *data = usb_get_intfdata(intf);	\
 865									\
 866	return sprintf(buf, "%d\n", data->name);			\
 867}									\
 868static ssize_t store_##name(struct device *dev,				\
 869			    struct device_attribute *attr,		\
 870			    const char *buf, size_t count)		\
 871{									\
 872	struct usb_interface *intf = to_usb_interface(dev);		\
 873	struct usbtmc_device_data *data = usb_get_intfdata(intf);	\
 874	ssize_t result;							\
 875	unsigned val;							\
 876									\
 877	result = sscanf(buf, "%u\n", &val);				\
 878	if (result != 1)						\
 879		result = -EINVAL;					\
 880	data->name = val;						\
 881	if (result < 0)							\
 882		return result;						\
 883	else								\
 884		return count;						\
 885}									\
 886static DEVICE_ATTR(name, S_IRUGO, show_##name, store_##name)
 887
 888data_attribute(TermCharEnabled);
 889data_attribute(auto_abort);
 890
 891static struct attribute *data_attrs[] = {
 892	&dev_attr_TermChar.attr,
 893	&dev_attr_TermCharEnabled.attr,
 894	&dev_attr_auto_abort.attr,
 895	NULL,
 896};
 897
 898static struct attribute_group data_attr_grp = {
 899	.attrs = data_attrs,
 900};
 901
 902static int usbtmc_ioctl_indicator_pulse(struct usbtmc_device_data *data)
 903{
 904	struct device *dev;
 905	u8 *buffer;
 906	int rv;
 907
 908	dev = &data->intf->dev;
 909
 910	buffer = kmalloc(2, GFP_KERNEL);
 911	if (!buffer)
 912		return -ENOMEM;
 913
 914	rv = usb_control_msg(data->usb_dev,
 915			     usb_rcvctrlpipe(data->usb_dev, 0),
 916			     USBTMC_REQUEST_INDICATOR_PULSE,
 917			     USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
 918			     0, 0, buffer, 0x01, USBTMC_TIMEOUT);
 919
 920	if (rv < 0) {
 921		dev_err(dev, "usb_control_msg returned %d\n", rv);
 922		goto exit;
 923	}
 924
 925	dev_dbg(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
 926
 927	if (buffer[0] != USBTMC_STATUS_SUCCESS) {
 928		dev_err(dev, "INDICATOR_PULSE returned %x\n", buffer[0]);
 929		rv = -EPERM;
 930		goto exit;
 931	}
 932	rv = 0;
 933
 934exit:
 935	kfree(buffer);
 936	return rv;
 937}
 938
 939static long usbtmc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 940{
 941	struct usbtmc_device_data *data;
 942	int retval = -EBADRQC;
 943
 944	data = file->private_data;
 945	mutex_lock(&data->io_mutex);
 946	if (data->zombie) {
 947		retval = -ENODEV;
 948		goto skip_io_on_zombie;
 949	}
 950
 951	switch (cmd) {
 952	case USBTMC_IOCTL_CLEAR_OUT_HALT:
 953		retval = usbtmc_ioctl_clear_out_halt(data);
 954		break;
 955
 956	case USBTMC_IOCTL_CLEAR_IN_HALT:
 957		retval = usbtmc_ioctl_clear_in_halt(data);
 958		break;
 959
 960	case USBTMC_IOCTL_INDICATOR_PULSE:
 961		retval = usbtmc_ioctl_indicator_pulse(data);
 962		break;
 963
 964	case USBTMC_IOCTL_CLEAR:
 965		retval = usbtmc_ioctl_clear(data);
 966		break;
 967
 968	case USBTMC_IOCTL_ABORT_BULK_OUT:
 969		retval = usbtmc_ioctl_abort_bulk_out(data);
 970		break;
 971
 972	case USBTMC_IOCTL_ABORT_BULK_IN:
 973		retval = usbtmc_ioctl_abort_bulk_in(data);
 974		break;
 975	}
 976
 977skip_io_on_zombie:
 978	mutex_unlock(&data->io_mutex);
 979	return retval;
 980}
 981
 982static const struct file_operations fops = {
 983	.owner		= THIS_MODULE,
 984	.read		= usbtmc_read,
 985	.write		= usbtmc_write,
 986	.open		= usbtmc_open,
 987	.release	= usbtmc_release,
 988	.unlocked_ioctl	= usbtmc_ioctl,
 989	.llseek		= default_llseek,
 990};
 991
 992static struct usb_class_driver usbtmc_class = {
 993	.name =		"usbtmc%d",
 994	.fops =		&fops,
 995	.minor_base =	USBTMC_MINOR_BASE,
 996};
 997
 998
 999static int usbtmc_probe(struct usb_interface *intf,
1000			const struct usb_device_id *id)
1001{
1002	struct usbtmc_device_data *data;
1003	struct usb_host_interface *iface_desc;
1004	struct usb_endpoint_descriptor *endpoint;
1005	int n;
1006	int retcode;
1007
1008	dev_dbg(&intf->dev, "%s called\n", __func__);
1009
1010	data = kmalloc(sizeof(struct usbtmc_device_data), GFP_KERNEL);
1011	if (!data) {
1012		dev_err(&intf->dev, "Unable to allocate kernel memory\n");
1013		return -ENOMEM;
1014	}
1015
1016	data->intf = intf;
1017	data->id = id;
1018	data->usb_dev = usb_get_dev(interface_to_usbdev(intf));
1019	usb_set_intfdata(intf, data);
1020	kref_init(&data->kref);
1021	mutex_init(&data->io_mutex);
1022	data->zombie = 0;
1023
1024	/* Initialize USBTMC bTag and other fields */
1025	data->bTag	= 1;
1026	data->TermCharEnabled = 0;
1027	data->TermChar = '\n';
1028
1029	/* USBTMC devices have only one setting, so use that */
1030	iface_desc = data->intf->cur_altsetting;
1031
1032	/* Find bulk in endpoint */
1033	for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1034		endpoint = &iface_desc->endpoint[n].desc;
1035
1036		if (usb_endpoint_is_bulk_in(endpoint)) {
1037			data->bulk_in = endpoint->bEndpointAddress;
1038			dev_dbg(&intf->dev, "Found bulk in endpoint at %u\n",
1039				data->bulk_in);
1040			break;
1041		}
1042	}
1043
1044	/* Find bulk out endpoint */
1045	for (n = 0; n < iface_desc->desc.bNumEndpoints; n++) {
1046		endpoint = &iface_desc->endpoint[n].desc;
1047
1048		if (usb_endpoint_is_bulk_out(endpoint)) {
1049			data->bulk_out = endpoint->bEndpointAddress;
1050			dev_dbg(&intf->dev, "Found Bulk out endpoint at %u\n",
1051				data->bulk_out);
1052			break;
1053		}
1054	}
1055
1056	retcode = get_capabilities(data);
1057	if (retcode)
1058		dev_err(&intf->dev, "can't read capabilities\n");
1059	else
1060		retcode = sysfs_create_group(&intf->dev.kobj,
1061					     &capability_attr_grp);
1062
1063	retcode = sysfs_create_group(&intf->dev.kobj, &data_attr_grp);
1064
1065	retcode = usb_register_dev(intf, &usbtmc_class);
1066	if (retcode) {
1067		dev_err(&intf->dev, "Not able to get a minor"
1068			" (base %u, slice default): %d\n", USBTMC_MINOR_BASE,
1069			retcode);
1070		goto error_register;
1071	}
1072	dev_dbg(&intf->dev, "Using minor number %d\n", intf->minor);
1073
1074	return 0;
1075
1076error_register:
1077	sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1078	sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1079	kref_put(&data->kref, usbtmc_delete);
1080	return retcode;
1081}
1082
1083static void usbtmc_disconnect(struct usb_interface *intf)
1084{
1085	struct usbtmc_device_data *data;
1086
1087	dev_dbg(&intf->dev, "usbtmc_disconnect called\n");
1088
1089	data = usb_get_intfdata(intf);
1090	usb_deregister_dev(intf, &usbtmc_class);
1091	sysfs_remove_group(&intf->dev.kobj, &capability_attr_grp);
1092	sysfs_remove_group(&intf->dev.kobj, &data_attr_grp);
1093	mutex_lock(&data->io_mutex);
1094	data->zombie = 1;
1095	mutex_unlock(&data->io_mutex);
1096	kref_put(&data->kref, usbtmc_delete);
1097}
1098
1099static int usbtmc_suspend(struct usb_interface *intf, pm_message_t message)
1100{
1101	/* this driver does not have pending URBs */
1102	return 0;
1103}
1104
1105static int usbtmc_resume(struct usb_interface *intf)
1106{
1107	return 0;
1108}
1109
1110static struct usb_driver usbtmc_driver = {
1111	.name		= "usbtmc",
1112	.id_table	= usbtmc_devices,
1113	.probe		= usbtmc_probe,
1114	.disconnect	= usbtmc_disconnect,
1115	.suspend	= usbtmc_suspend,
1116	.resume		= usbtmc_resume,
1117};
1118
1119module_usb_driver(usbtmc_driver);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1120
1121MODULE_LICENSE("GPL");