Linux Audio

Check our new training course

Embedded Linux Audio

Check our new training course
with Creative Commons CC-BY-SA
lecture materials

Bootlin logo

Elixir Cross Referencer

Loading...
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
/*
 * drivers/usb/core/sysfs.c
 *
 * (C) Copyright 2002 David Brownell
 * (C) Copyright 2002,2004 Greg Kroah-Hartman
 * (C) Copyright 2002,2004 IBM Corp.
 *
 * All of the sysfs file attributes for usb devices and interfaces.
 *
 */


#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/usb.h>
#include <linux/usb/quirks.h>
#include "usb.h"

/* Active configuration fields */
#define usb_actconfig_show(field, multiplier, format_string)		\
static ssize_t  show_##field(struct device *dev,			\
		struct device_attribute *attr, char *buf)		\
{									\
	struct usb_device *udev;					\
	struct usb_host_config *actconfig;				\
									\
	udev = to_usb_device(dev);					\
	actconfig = udev->actconfig;					\
	if (actconfig)							\
		return sprintf(buf, format_string,			\
				actconfig->desc.field * multiplier);	\
	else								\
		return 0;						\
}									\

#define usb_actconfig_attr(field, multiplier, format_string)		\
usb_actconfig_show(field, multiplier, format_string)			\
static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);

usb_actconfig_attr(bNumInterfaces, 1, "%2d\n")
usb_actconfig_attr(bmAttributes, 1, "%2x\n")
usb_actconfig_attr(bMaxPower, 2, "%3dmA\n")

static ssize_t show_configuration_string(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct usb_device *udev;
	struct usb_host_config *actconfig;

	udev = to_usb_device(dev);
	actconfig = udev->actconfig;
	if ((!actconfig) || (!actconfig->string))
		return 0;
	return sprintf(buf, "%s\n", actconfig->string);
}
static DEVICE_ATTR(configuration, S_IRUGO, show_configuration_string, NULL);

/* configuration value is always present, and r/w */
usb_actconfig_show(bConfigurationValue, 1, "%u\n");

static ssize_t
set_bConfigurationValue(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t count)
{
	struct usb_device	*udev = to_usb_device(dev);
	int			config, value;

	if (sscanf(buf, "%d", &config) != 1 || config < -1 || config > 255)
		return -EINVAL;
	usb_lock_device(udev);
	value = usb_set_configuration(udev, config);
	usb_unlock_device(udev);
	return (value < 0) ? value : count;
}

static DEVICE_ATTR(bConfigurationValue, S_IRUGO | S_IWUSR,
		show_bConfigurationValue, set_bConfigurationValue);

/* String fields */
#define usb_string_attr(name)						\
static ssize_t  show_##name(struct device *dev,				\
		struct device_attribute *attr, char *buf)		\
{									\
	struct usb_device *udev;					\
	int retval;							\
									\
	udev = to_usb_device(dev);					\
	usb_lock_device(udev);						\
	retval = sprintf(buf, "%s\n", udev->name);			\
	usb_unlock_device(udev);					\
	return retval;							\
}									\
static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL);

usb_string_attr(product);
usb_string_attr(manufacturer);
usb_string_attr(serial);

static ssize_t
show_speed(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_device *udev;
	char *speed;

	udev = to_usb_device(dev);

	switch (udev->speed) {
	case USB_SPEED_LOW:
		speed = "1.5";
		break;
	case USB_SPEED_UNKNOWN:
	case USB_SPEED_FULL:
		speed = "12";
		break;
	case USB_SPEED_HIGH:
		speed = "480";
		break;
	case USB_SPEED_WIRELESS:
		speed = "480";
		break;
	case USB_SPEED_SUPER:
		speed = "5000";
		break;
	default:
		speed = "unknown";
	}
	return sprintf(buf, "%s\n", speed);
}
static DEVICE_ATTR(speed, S_IRUGO, show_speed, NULL);

static ssize_t
show_busnum(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_device *udev;

	udev = to_usb_device(dev);
	return sprintf(buf, "%d\n", udev->bus->busnum);
}
static DEVICE_ATTR(busnum, S_IRUGO, show_busnum, NULL);

static ssize_t
show_devnum(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_device *udev;

	udev = to_usb_device(dev);
	return sprintf(buf, "%d\n", udev->devnum);
}
static DEVICE_ATTR(devnum, S_IRUGO, show_devnum, NULL);

static ssize_t
show_devpath(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_device *udev;

	udev = to_usb_device(dev);
	return sprintf(buf, "%s\n", udev->devpath);
}
static DEVICE_ATTR(devpath, S_IRUGO, show_devpath, NULL);

static ssize_t
show_version(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_device *udev;
	u16 bcdUSB;

	udev = to_usb_device(dev);
	bcdUSB = le16_to_cpu(udev->descriptor.bcdUSB);
	return sprintf(buf, "%2x.%02x\n", bcdUSB >> 8, bcdUSB & 0xff);
}
static DEVICE_ATTR(version, S_IRUGO, show_version, NULL);

static ssize_t
show_maxchild(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_device *udev;

	udev = to_usb_device(dev);
	return sprintf(buf, "%d\n", udev->maxchild);
}
static DEVICE_ATTR(maxchild, S_IRUGO, show_maxchild, NULL);

static ssize_t
show_quirks(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_device *udev;

	udev = to_usb_device(dev);
	return sprintf(buf, "0x%x\n", udev->quirks);
}
static DEVICE_ATTR(quirks, S_IRUGO, show_quirks, NULL);

static ssize_t
show_avoid_reset_quirk(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_device *udev;

	udev = to_usb_device(dev);
	return sprintf(buf, "%d\n", !!(udev->quirks & USB_QUIRK_RESET_MORPHS));
}

static ssize_t
set_avoid_reset_quirk(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t count)
{
	struct usb_device	*udev = to_usb_device(dev);
	int			config;

	if (sscanf(buf, "%d", &config) != 1 || config < 0 || config > 1)
		return -EINVAL;
	usb_lock_device(udev);
	if (config)
		udev->quirks |= USB_QUIRK_RESET_MORPHS;
	else
		udev->quirks &= ~USB_QUIRK_RESET_MORPHS;
	usb_unlock_device(udev);
	return count;
}

static DEVICE_ATTR(avoid_reset_quirk, S_IRUGO | S_IWUSR,
		show_avoid_reset_quirk, set_avoid_reset_quirk);

static ssize_t
show_urbnum(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_device *udev;

	udev = to_usb_device(dev);
	return sprintf(buf, "%d\n", atomic_read(&udev->urbnum));
}
static DEVICE_ATTR(urbnum, S_IRUGO, show_urbnum, NULL);

static ssize_t
show_removable(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_device *udev;
	char *state;

	udev = to_usb_device(dev);

	switch (udev->removable) {
	case USB_DEVICE_REMOVABLE:
		state = "removable";
		break;
	case USB_DEVICE_FIXED:
		state = "fixed";
		break;
	default:
		state = "unknown";
	}

	return sprintf(buf, "%s\n", state);
}
static DEVICE_ATTR(removable, S_IRUGO, show_removable, NULL);

#ifdef	CONFIG_PM

static ssize_t
show_persist(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_device *udev = to_usb_device(dev);

	return sprintf(buf, "%d\n", udev->persist_enabled);
}

static ssize_t
set_persist(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t count)
{
	struct usb_device *udev = to_usb_device(dev);
	int value;

	/* Hubs are always enabled for USB_PERSIST */
	if (udev->descriptor.bDeviceClass == USB_CLASS_HUB)
		return -EPERM;

	if (sscanf(buf, "%d", &value) != 1)
		return -EINVAL;

	usb_lock_device(udev);
	udev->persist_enabled = !!value;
	usb_unlock_device(udev);
	return count;
}

static DEVICE_ATTR(persist, S_IRUGO | S_IWUSR, show_persist, set_persist);

static int add_persist_attributes(struct device *dev)
{
	int rc = 0;

	if (is_usb_device(dev)) {
		struct usb_device *udev = to_usb_device(dev);

		/* Hubs are automatically enabled for USB_PERSIST,
		 * no point in creating the attribute file.
		 */
		if (udev->descriptor.bDeviceClass != USB_CLASS_HUB)
			rc = sysfs_add_file_to_group(&dev->kobj,
					&dev_attr_persist.attr,
					power_group_name);
	}
	return rc;
}

static void remove_persist_attributes(struct device *dev)
{
	sysfs_remove_file_from_group(&dev->kobj,
			&dev_attr_persist.attr,
			power_group_name);
}
#else

#define add_persist_attributes(dev)	0
#define remove_persist_attributes(dev)	do {} while (0)

#endif	/* CONFIG_PM */

#ifdef	CONFIG_USB_SUSPEND

static ssize_t
show_connected_duration(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	struct usb_device *udev = to_usb_device(dev);

	return sprintf(buf, "%u\n",
			jiffies_to_msecs(jiffies - udev->connect_time));
}

static DEVICE_ATTR(connected_duration, S_IRUGO, show_connected_duration, NULL);

/*
 * If the device is resumed, the last time the device was suspended has
 * been pre-subtracted from active_duration.  We add the current time to
 * get the duration that the device was actually active.
 *
 * If the device is suspended, the active_duration is up-to-date.
 */
static ssize_t
show_active_duration(struct device *dev, struct device_attribute *attr,
		char *buf)
{
	struct usb_device *udev = to_usb_device(dev);
	int duration;

	if (udev->state != USB_STATE_SUSPENDED)
		duration = jiffies_to_msecs(jiffies + udev->active_duration);
	else
		duration = jiffies_to_msecs(udev->active_duration);
	return sprintf(buf, "%u\n", duration);
}

static DEVICE_ATTR(active_duration, S_IRUGO, show_active_duration, NULL);

static ssize_t
show_autosuspend(struct device *dev, struct device_attribute *attr, char *buf)
{
	return sprintf(buf, "%d\n", dev->power.autosuspend_delay / 1000);
}

static ssize_t
set_autosuspend(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t count)
{
	int value;

	if (sscanf(buf, "%d", &value) != 1 || value >= INT_MAX/1000 ||
			value <= -INT_MAX/1000)
		return -EINVAL;

	pm_runtime_set_autosuspend_delay(dev, value * 1000);
	return count;
}

static DEVICE_ATTR(autosuspend, S_IRUGO | S_IWUSR,
		show_autosuspend, set_autosuspend);

static const char on_string[] = "on";
static const char auto_string[] = "auto";

static void warn_level(void) {
	static int level_warned;

	if (!level_warned) {
		level_warned = 1;
		printk(KERN_WARNING "WARNING! power/level is deprecated; "
				"use power/control instead\n");
	}
}

static ssize_t
show_level(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct usb_device *udev = to_usb_device(dev);
	const char *p = auto_string;

	warn_level();
	if (udev->state != USB_STATE_SUSPENDED && !udev->dev.power.runtime_auto)
		p = on_string;
	return sprintf(buf, "%s\n", p);
}

static ssize_t
set_level(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t count)
{
	struct usb_device *udev = to_usb_device(dev);
	int len = count;
	char *cp;
	int rc = count;

	warn_level();
	cp = memchr(buf, '\n', count);
	if (cp)
		len = cp - buf;

	usb_lock_device(udev);

	if (len == sizeof on_string - 1 &&
			strncmp(buf, on_string, len) == 0)
		usb_disable_autosuspend(udev);

	else if (len == sizeof auto_string - 1 &&
			strncmp(buf, auto_string, len) == 0)
		usb_enable_autosuspend(udev);

	else
		rc = -EINVAL;

	usb_unlock_device(udev);
	return rc;
}

static DEVICE_ATTR(level, S_IRUGO | S_IWUSR, show_level, set_level);

static ssize_t
show_usb2_hardware_lpm(struct device *dev, struct device_attribute *attr,
				char *buf)
{
	struct usb_device *udev = to_usb_device(dev);
	const char *p;

	if (udev->usb2_hw_lpm_enabled == 1)
		p = "enabled";
	else
		p = "disabled";

	return sprintf(buf, "%s\n", p);
}

static ssize_t
set_usb2_hardware_lpm(struct device *dev, struct device_attribute *attr,
		const char *buf, size_t count)
{
	struct usb_device *udev = to_usb_device(dev);
	bool value;
	int ret;

	usb_lock_device(udev);

	ret = strtobool(buf, &value);

	if (!ret)
		ret = usb_set_usb2_hardware_lpm(udev, value);

	usb_unlock_device(udev);

	if (!ret)
		return count;

	return ret;
}

static DEVICE_ATTR(usb2_hardware_lpm, S_IRUGO | S_IWUSR, show_usb2_hardware_lpm,
			set_usb2_hardware_lpm);

static struct attribute *usb2_hardware_lpm_attr[] = {
	&dev_attr_usb2_hardware_lpm.attr,
	NULL,
};
static struct attribute_group usb2_hardware_lpm_attr_group = {
	.name	= power_group_name,
	.attrs	= usb2_hardware_lpm_attr,
};

static struct attribute *power_attrs[] = {
	&dev_attr_autosuspend.attr,
	&dev_attr_level.attr,
	&dev_attr_connected_duration.attr,
	&dev_attr_active_duration.attr,
	NULL,
};
static struct attribute_group power_attr_group = {
	.name	= power_group_name,
	.attrs	= power_attrs,
};

static int add_power_attributes(struct device *dev)
{
	int rc = 0;

	if (is_usb_device(dev)) {
		struct usb_device *udev = to_usb_device(dev);
		rc = sysfs_merge_group(&dev->kobj, &power_attr_group);
		if (udev->usb2_hw_lpm_capable == 1)
			rc = sysfs_merge_group(&dev->kobj,
					&usb2_hardware_lpm_attr_group);
	}

	return rc;
}

static void remove_power_attributes(struct device *dev)
{
	sysfs_unmerge_group(&dev->kobj, &usb2_hardware_lpm_attr_group);
	sysfs_unmerge_group(&dev->kobj, &power_attr_group);
}

#else

#define add_power_attributes(dev)	0
#define remove_power_attributes(dev)	do {} while (0)

#endif	/* CONFIG_USB_SUSPEND */


/* Descriptor fields */
#define usb_descriptor_attr_le16(field, format_string)			\
static ssize_t								\
show_##field(struct device *dev, struct device_attribute *attr,	\
		char *buf)						\
{									\
	struct usb_device *udev;					\
									\
	udev = to_usb_device(dev);					\
	return sprintf(buf, format_string, 				\
			le16_to_cpu(udev->descriptor.field));		\
}									\
static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);

usb_descriptor_attr_le16(idVendor, "%04x\n")
usb_descriptor_attr_le16(idProduct, "%04x\n")
usb_descriptor_attr_le16(bcdDevice, "%04x\n")

#define usb_descriptor_attr(field, format_string)			\
static ssize_t								\
show_##field(struct device *dev, struct device_attribute *attr,	\
		char *buf)						\
{									\
	struct usb_device *udev;					\
									\
	udev = to_usb_device(dev);					\
	return sprintf(buf, format_string, udev->descriptor.field);	\
}									\
static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);

usb_descriptor_attr(bDeviceClass, "%02x\n")
usb_descriptor_attr(bDeviceSubClass, "%02x\n")
usb_descriptor_attr(bDeviceProtocol, "%02x\n")
usb_descriptor_attr(bNumConfigurations, "%d\n")
usb_descriptor_attr(bMaxPacketSize0, "%d\n")



/* show if the device is authorized (1) or not (0) */
static ssize_t usb_dev_authorized_show(struct device *dev,
				       struct device_attribute *attr,
				       char *buf)
{
	struct usb_device *usb_dev = to_usb_device(dev);
	return snprintf(buf, PAGE_SIZE, "%u\n", usb_dev->authorized);
}


/*
 * Authorize a device to be used in the system
 *
 * Writing a 0 deauthorizes the device, writing a 1 authorizes it.
 */
static ssize_t usb_dev_authorized_store(struct device *dev,
					struct device_attribute *attr,
					const char *buf, size_t size)
{
	ssize_t result;
	struct usb_device *usb_dev = to_usb_device(dev);
	unsigned val;
	result = sscanf(buf, "%u\n", &val);
	if (result != 1)
		result = -EINVAL;
	else if (val == 0)
		result = usb_deauthorize_device(usb_dev);
	else
		result = usb_authorize_device(usb_dev);
	return result < 0? result : size;
}

static DEVICE_ATTR(authorized, 0644,
	    usb_dev_authorized_show, usb_dev_authorized_store);

/* "Safely remove a device" */
static ssize_t usb_remove_store(struct device *dev,
		struct device_attribute *attr,
		const char *buf, size_t count)
{
	struct usb_device *udev = to_usb_device(dev);
	int rc = 0;

	usb_lock_device(udev);
	if (udev->state != USB_STATE_NOTATTACHED) {

		/* To avoid races, first unconfigure and then remove */
		usb_set_configuration(udev, -1);
		rc = usb_remove_device(udev);
	}
	if (rc == 0)
		rc = count;
	usb_unlock_device(udev);
	return rc;
}
static DEVICE_ATTR(remove, 0200, NULL, usb_remove_store);


static struct attribute *dev_attrs[] = {
	/* current configuration's attributes */
	&dev_attr_configuration.attr,
	&dev_attr_bNumInterfaces.attr,
	&dev_attr_bConfigurationValue.attr,
	&dev_attr_bmAttributes.attr,
	&dev_attr_bMaxPower.attr,
	/* device attributes */
	&dev_attr_urbnum.attr,
	&dev_attr_idVendor.attr,
	&dev_attr_idProduct.attr,
	&dev_attr_bcdDevice.attr,
	&dev_attr_bDeviceClass.attr,
	&dev_attr_bDeviceSubClass.attr,
	&dev_attr_bDeviceProtocol.attr,
	&dev_attr_bNumConfigurations.attr,
	&dev_attr_bMaxPacketSize0.attr,
	&dev_attr_speed.attr,
	&dev_attr_busnum.attr,
	&dev_attr_devnum.attr,
	&dev_attr_devpath.attr,
	&dev_attr_version.attr,
	&dev_attr_maxchild.attr,
	&dev_attr_quirks.attr,
	&dev_attr_avoid_reset_quirk.attr,
	&dev_attr_authorized.attr,
	&dev_attr_remove.attr,
	&dev_attr_removable.attr,
	NULL,
};
static struct attribute_group dev_attr_grp = {
	.attrs = dev_attrs,
};

/* When modifying this list, be sure to modify dev_string_attrs_are_visible()
 * accordingly.
 */
static struct attribute *dev_string_attrs[] = {
	&dev_attr_manufacturer.attr,
	&dev_attr_product.attr,
	&dev_attr_serial.attr,
	NULL
};

static umode_t dev_string_attrs_are_visible(struct kobject *kobj,
		struct attribute *a, int n)
{
	struct device *dev = container_of(kobj, struct device, kobj);
	struct usb_device *udev = to_usb_device(dev);

	if (a == &dev_attr_manufacturer.attr) {
		if (udev->manufacturer == NULL)
			return 0;
	} else if (a == &dev_attr_product.attr) {
		if (udev->product == NULL)
			return 0;
	} else if (a == &dev_attr_serial.attr) {
		if (udev->serial == NULL)
			return 0;
	}
	return a->mode;
}

static struct attribute_group dev_string_attr_grp = {
	.attrs =	dev_string_attrs,
	.is_visible =	dev_string_attrs_are_visible,
};

const struct attribute_group *usb_device_groups[] = {
	&dev_attr_grp,
	&dev_string_attr_grp,
	NULL
};

/* Binary descriptors */

static ssize_t
read_descriptors(struct file *filp, struct kobject *kobj,
		struct bin_attribute *attr,
		char *buf, loff_t off, size_t count)
{
	struct device *dev = container_of(kobj, struct device, kobj);
	struct usb_device *udev = to_usb_device(dev);
	size_t nleft = count;
	size_t srclen, n;
	int cfgno;
	void *src;

	/* The binary attribute begins with the device descriptor.
	 * Following that are the raw descriptor entries for all the
	 * configurations (config plus subsidiary descriptors).
	 */
	for (cfgno = -1; cfgno < udev->descriptor.bNumConfigurations &&
			nleft > 0; ++cfgno) {
		if (cfgno < 0) {
			src = &udev->descriptor;
			srclen = sizeof(struct usb_device_descriptor);
		} else {
			src = udev->rawdescriptors[cfgno];
			srclen = __le16_to_cpu(udev->config[cfgno].desc.
					wTotalLength);
		}
		if (off < srclen) {
			n = min(nleft, srclen - (size_t) off);
			memcpy(buf, src + off, n);
			nleft -= n;
			buf += n;
			off = 0;
		} else {
			off -= srclen;
		}
	}
	return count - nleft;
}

static struct bin_attribute dev_bin_attr_descriptors = {
	.attr = {.name = "descriptors", .mode = 0444},
	.read = read_descriptors,
	.size = 18 + 65535,	/* dev descr + max-size raw descriptor */
};

int usb_create_sysfs_dev_files(struct usb_device *udev)
{
	struct device *dev = &udev->dev;
	int retval;

	retval = device_create_bin_file(dev, &dev_bin_attr_descriptors);
	if (retval)
		goto error;

	retval = add_persist_attributes(dev);
	if (retval)
		goto error;

	retval = add_power_attributes(dev);
	if (retval)
		goto error;
	return retval;
error:
	usb_remove_sysfs_dev_files(udev);
	return retval;
}

void usb_remove_sysfs_dev_files(struct usb_device *udev)
{
	struct device *dev = &udev->dev;

	remove_power_attributes(dev);
	remove_persist_attributes(dev);
	device_remove_bin_file(dev, &dev_bin_attr_descriptors);
}

/* Interface Accociation Descriptor fields */
#define usb_intf_assoc_attr(field, format_string)			\
static ssize_t								\
show_iad_##field(struct device *dev, struct device_attribute *attr,	\
		char *buf)						\
{									\
	struct usb_interface *intf = to_usb_interface(dev);		\
									\
	return sprintf(buf, format_string,				\
			intf->intf_assoc->field); 			\
}									\
static DEVICE_ATTR(iad_##field, S_IRUGO, show_iad_##field, NULL);

usb_intf_assoc_attr(bFirstInterface, "%02x\n")
usb_intf_assoc_attr(bInterfaceCount, "%02d\n")
usb_intf_assoc_attr(bFunctionClass, "%02x\n")
usb_intf_assoc_attr(bFunctionSubClass, "%02x\n")
usb_intf_assoc_attr(bFunctionProtocol, "%02x\n")

/* Interface fields */
#define usb_intf_attr(field, format_string)				\
static ssize_t								\
show_##field(struct device *dev, struct device_attribute *attr,	\
		char *buf)						\
{									\
	struct usb_interface *intf = to_usb_interface(dev);		\
									\
	return sprintf(buf, format_string,				\
			intf->cur_altsetting->desc.field); 		\
}									\
static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);

usb_intf_attr(bInterfaceNumber, "%02x\n")
usb_intf_attr(bAlternateSetting, "%2d\n")
usb_intf_attr(bNumEndpoints, "%02x\n")
usb_intf_attr(bInterfaceClass, "%02x\n")
usb_intf_attr(bInterfaceSubClass, "%02x\n")
usb_intf_attr(bInterfaceProtocol, "%02x\n")

static ssize_t show_interface_string(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct usb_interface *intf;
	char *string;

	intf = to_usb_interface(dev);
	string = intf->cur_altsetting->string;
	barrier();		/* The altsetting might change! */

	if (!string)
		return 0;
	return sprintf(buf, "%s\n", string);
}
static DEVICE_ATTR(interface, S_IRUGO, show_interface_string, NULL);

static ssize_t show_modalias(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct usb_interface *intf;
	struct usb_device *udev;
	struct usb_host_interface *alt;

	intf = to_usb_interface(dev);
	udev = interface_to_usbdev(intf);
	alt = intf->cur_altsetting;

	return sprintf(buf, "usb:v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02X"
			"ic%02Xisc%02Xip%02X\n",
			le16_to_cpu(udev->descriptor.idVendor),
			le16_to_cpu(udev->descriptor.idProduct),
			le16_to_cpu(udev->descriptor.bcdDevice),
			udev->descriptor.bDeviceClass,
			udev->descriptor.bDeviceSubClass,
			udev->descriptor.bDeviceProtocol,
			alt->desc.bInterfaceClass,
			alt->desc.bInterfaceSubClass,
			alt->desc.bInterfaceProtocol);
}
static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL);

static ssize_t show_supports_autosuspend(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct usb_interface *intf;
	struct usb_device *udev;
	int ret;

	intf = to_usb_interface(dev);
	udev = interface_to_usbdev(intf);

	usb_lock_device(udev);
	/* Devices will be autosuspended even when an interface isn't claimed */
	if (!intf->dev.driver ||
			to_usb_driver(intf->dev.driver)->supports_autosuspend)
		ret = sprintf(buf, "%u\n", 1);
	else
		ret = sprintf(buf, "%u\n", 0);
	usb_unlock_device(udev);

	return ret;
}
static DEVICE_ATTR(supports_autosuspend, S_IRUGO, show_supports_autosuspend, NULL);

static struct attribute *intf_attrs[] = {
	&dev_attr_bInterfaceNumber.attr,
	&dev_attr_bAlternateSetting.attr,
	&dev_attr_bNumEndpoints.attr,
	&dev_attr_bInterfaceClass.attr,
	&dev_attr_bInterfaceSubClass.attr,
	&dev_attr_bInterfaceProtocol.attr,
	&dev_attr_modalias.attr,
	&dev_attr_supports_autosuspend.attr,
	NULL,
};
static struct attribute_group intf_attr_grp = {
	.attrs = intf_attrs,
};

static struct attribute *intf_assoc_attrs[] = {
	&dev_attr_iad_bFirstInterface.attr,
	&dev_attr_iad_bInterfaceCount.attr,
	&dev_attr_iad_bFunctionClass.attr,
	&dev_attr_iad_bFunctionSubClass.attr,
	&dev_attr_iad_bFunctionProtocol.attr,
	NULL,
};

static umode_t intf_assoc_attrs_are_visible(struct kobject *kobj,
		struct attribute *a, int n)
{
	struct device *dev = container_of(kobj, struct device, kobj);
	struct usb_interface *intf = to_usb_interface(dev);

	if (intf->intf_assoc == NULL)
		return 0;
	return a->mode;
}

static struct attribute_group intf_assoc_attr_grp = {
	.attrs =	intf_assoc_attrs,
	.is_visible =	intf_assoc_attrs_are_visible,
};

const struct attribute_group *usb_interface_groups[] = {
	&intf_attr_grp,
	&intf_assoc_attr_grp,
	NULL
};

void usb_create_sysfs_intf_files(struct usb_interface *intf)
{
	struct usb_device *udev = interface_to_usbdev(intf);
	struct usb_host_interface *alt = intf->cur_altsetting;

	if (intf->sysfs_files_created || intf->unregistering)
		return;

	if (!alt->string && !(udev->quirks & USB_QUIRK_CONFIG_INTF_STRINGS))
		alt->string = usb_cache_string(udev, alt->desc.iInterface);
	if (alt->string && device_create_file(&intf->dev, &dev_attr_interface))
		;	/* We don't actually care if the function fails. */
	intf->sysfs_files_created = 1;
}

void usb_remove_sysfs_intf_files(struct usb_interface *intf)
{
	if (!intf->sysfs_files_created)
		return;

	device_remove_file(&intf->dev, &dev_attr_interface);
	intf->sysfs_files_created = 0;
}