xref: /openbmc/linux/drivers/usb/core/sysfs.c (revision 95c96174)
1 /*
2  * drivers/usb/core/sysfs.c
3  *
4  * (C) Copyright 2002 David Brownell
5  * (C) Copyright 2002,2004 Greg Kroah-Hartman
6  * (C) Copyright 2002,2004 IBM Corp.
7  *
8  * All of the sysfs file attributes for usb devices and interfaces.
9  *
10  */
11 
12 
13 #include <linux/kernel.h>
14 #include <linux/string.h>
15 #include <linux/usb.h>
16 #include <linux/usb/quirks.h>
17 #include "usb.h"
18 
19 /* Active configuration fields */
20 #define usb_actconfig_show(field, multiplier, format_string)		\
21 static ssize_t  show_##field(struct device *dev,			\
22 		struct device_attribute *attr, char *buf)		\
23 {									\
24 	struct usb_device *udev;					\
25 	struct usb_host_config *actconfig;				\
26 									\
27 	udev = to_usb_device(dev);					\
28 	actconfig = udev->actconfig;					\
29 	if (actconfig)							\
30 		return sprintf(buf, format_string,			\
31 				actconfig->desc.field * multiplier);	\
32 	else								\
33 		return 0;						\
34 }									\
35 
36 #define usb_actconfig_attr(field, multiplier, format_string)		\
37 usb_actconfig_show(field, multiplier, format_string)			\
38 static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);
39 
40 usb_actconfig_attr(bNumInterfaces, 1, "%2d\n")
41 usb_actconfig_attr(bmAttributes, 1, "%2x\n")
42 usb_actconfig_attr(bMaxPower, 2, "%3dmA\n")
43 
44 static ssize_t show_configuration_string(struct device *dev,
45 		struct device_attribute *attr, char *buf)
46 {
47 	struct usb_device *udev;
48 	struct usb_host_config *actconfig;
49 
50 	udev = to_usb_device(dev);
51 	actconfig = udev->actconfig;
52 	if ((!actconfig) || (!actconfig->string))
53 		return 0;
54 	return sprintf(buf, "%s\n", actconfig->string);
55 }
56 static DEVICE_ATTR(configuration, S_IRUGO, show_configuration_string, NULL);
57 
58 /* configuration value is always present, and r/w */
59 usb_actconfig_show(bConfigurationValue, 1, "%u\n");
60 
61 static ssize_t
62 set_bConfigurationValue(struct device *dev, struct device_attribute *attr,
63 		const char *buf, size_t count)
64 {
65 	struct usb_device	*udev = to_usb_device(dev);
66 	int			config, value;
67 
68 	if (sscanf(buf, "%d", &config) != 1 || config < -1 || config > 255)
69 		return -EINVAL;
70 	usb_lock_device(udev);
71 	value = usb_set_configuration(udev, config);
72 	usb_unlock_device(udev);
73 	return (value < 0) ? value : count;
74 }
75 
76 static DEVICE_ATTR(bConfigurationValue, S_IRUGO | S_IWUSR,
77 		show_bConfigurationValue, set_bConfigurationValue);
78 
79 /* String fields */
80 #define usb_string_attr(name)						\
81 static ssize_t  show_##name(struct device *dev,				\
82 		struct device_attribute *attr, char *buf)		\
83 {									\
84 	struct usb_device *udev;					\
85 	int retval;							\
86 									\
87 	udev = to_usb_device(dev);					\
88 	usb_lock_device(udev);						\
89 	retval = sprintf(buf, "%s\n", udev->name);			\
90 	usb_unlock_device(udev);					\
91 	return retval;							\
92 }									\
93 static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL);
94 
95 usb_string_attr(product);
96 usb_string_attr(manufacturer);
97 usb_string_attr(serial);
98 
99 static ssize_t
100 show_speed(struct device *dev, struct device_attribute *attr, char *buf)
101 {
102 	struct usb_device *udev;
103 	char *speed;
104 
105 	udev = to_usb_device(dev);
106 
107 	switch (udev->speed) {
108 	case USB_SPEED_LOW:
109 		speed = "1.5";
110 		break;
111 	case USB_SPEED_UNKNOWN:
112 	case USB_SPEED_FULL:
113 		speed = "12";
114 		break;
115 	case USB_SPEED_HIGH:
116 		speed = "480";
117 		break;
118 	case USB_SPEED_WIRELESS:
119 		speed = "480";
120 		break;
121 	case USB_SPEED_SUPER:
122 		speed = "5000";
123 		break;
124 	default:
125 		speed = "unknown";
126 	}
127 	return sprintf(buf, "%s\n", speed);
128 }
129 static DEVICE_ATTR(speed, S_IRUGO, show_speed, NULL);
130 
131 static ssize_t
132 show_busnum(struct device *dev, struct device_attribute *attr, char *buf)
133 {
134 	struct usb_device *udev;
135 
136 	udev = to_usb_device(dev);
137 	return sprintf(buf, "%d\n", udev->bus->busnum);
138 }
139 static DEVICE_ATTR(busnum, S_IRUGO, show_busnum, NULL);
140 
141 static ssize_t
142 show_devnum(struct device *dev, struct device_attribute *attr, char *buf)
143 {
144 	struct usb_device *udev;
145 
146 	udev = to_usb_device(dev);
147 	return sprintf(buf, "%d\n", udev->devnum);
148 }
149 static DEVICE_ATTR(devnum, S_IRUGO, show_devnum, NULL);
150 
151 static ssize_t
152 show_devpath(struct device *dev, struct device_attribute *attr, char *buf)
153 {
154 	struct usb_device *udev;
155 
156 	udev = to_usb_device(dev);
157 	return sprintf(buf, "%s\n", udev->devpath);
158 }
159 static DEVICE_ATTR(devpath, S_IRUGO, show_devpath, NULL);
160 
161 static ssize_t
162 show_version(struct device *dev, struct device_attribute *attr, char *buf)
163 {
164 	struct usb_device *udev;
165 	u16 bcdUSB;
166 
167 	udev = to_usb_device(dev);
168 	bcdUSB = le16_to_cpu(udev->descriptor.bcdUSB);
169 	return sprintf(buf, "%2x.%02x\n", bcdUSB >> 8, bcdUSB & 0xff);
170 }
171 static DEVICE_ATTR(version, S_IRUGO, show_version, NULL);
172 
173 static ssize_t
174 show_maxchild(struct device *dev, struct device_attribute *attr, char *buf)
175 {
176 	struct usb_device *udev;
177 
178 	udev = to_usb_device(dev);
179 	return sprintf(buf, "%d\n", udev->maxchild);
180 }
181 static DEVICE_ATTR(maxchild, S_IRUGO, show_maxchild, NULL);
182 
183 static ssize_t
184 show_quirks(struct device *dev, struct device_attribute *attr, char *buf)
185 {
186 	struct usb_device *udev;
187 
188 	udev = to_usb_device(dev);
189 	return sprintf(buf, "0x%x\n", udev->quirks);
190 }
191 static DEVICE_ATTR(quirks, S_IRUGO, show_quirks, NULL);
192 
193 static ssize_t
194 show_avoid_reset_quirk(struct device *dev, struct device_attribute *attr, char *buf)
195 {
196 	struct usb_device *udev;
197 
198 	udev = to_usb_device(dev);
199 	return sprintf(buf, "%d\n", !!(udev->quirks & USB_QUIRK_RESET_MORPHS));
200 }
201 
202 static ssize_t
203 set_avoid_reset_quirk(struct device *dev, struct device_attribute *attr,
204 		const char *buf, size_t count)
205 {
206 	struct usb_device	*udev = to_usb_device(dev);
207 	int			config;
208 
209 	if (sscanf(buf, "%d", &config) != 1 || config < 0 || config > 1)
210 		return -EINVAL;
211 	usb_lock_device(udev);
212 	if (config)
213 		udev->quirks |= USB_QUIRK_RESET_MORPHS;
214 	else
215 		udev->quirks &= ~USB_QUIRK_RESET_MORPHS;
216 	usb_unlock_device(udev);
217 	return count;
218 }
219 
220 static DEVICE_ATTR(avoid_reset_quirk, S_IRUGO | S_IWUSR,
221 		show_avoid_reset_quirk, set_avoid_reset_quirk);
222 
223 static ssize_t
224 show_urbnum(struct device *dev, struct device_attribute *attr, char *buf)
225 {
226 	struct usb_device *udev;
227 
228 	udev = to_usb_device(dev);
229 	return sprintf(buf, "%d\n", atomic_read(&udev->urbnum));
230 }
231 static DEVICE_ATTR(urbnum, S_IRUGO, show_urbnum, NULL);
232 
233 static ssize_t
234 show_removable(struct device *dev, struct device_attribute *attr, char *buf)
235 {
236 	struct usb_device *udev;
237 	char *state;
238 
239 	udev = to_usb_device(dev);
240 
241 	switch (udev->removable) {
242 	case USB_DEVICE_REMOVABLE:
243 		state = "removable";
244 		break;
245 	case USB_DEVICE_FIXED:
246 		state = "fixed";
247 		break;
248 	default:
249 		state = "unknown";
250 	}
251 
252 	return sprintf(buf, "%s\n", state);
253 }
254 static DEVICE_ATTR(removable, S_IRUGO, show_removable, NULL);
255 
256 #ifdef	CONFIG_PM
257 
258 static ssize_t
259 show_persist(struct device *dev, struct device_attribute *attr, char *buf)
260 {
261 	struct usb_device *udev = to_usb_device(dev);
262 
263 	return sprintf(buf, "%d\n", udev->persist_enabled);
264 }
265 
266 static ssize_t
267 set_persist(struct device *dev, struct device_attribute *attr,
268 		const char *buf, size_t count)
269 {
270 	struct usb_device *udev = to_usb_device(dev);
271 	int value;
272 
273 	/* Hubs are always enabled for USB_PERSIST */
274 	if (udev->descriptor.bDeviceClass == USB_CLASS_HUB)
275 		return -EPERM;
276 
277 	if (sscanf(buf, "%d", &value) != 1)
278 		return -EINVAL;
279 
280 	usb_lock_device(udev);
281 	udev->persist_enabled = !!value;
282 	usb_unlock_device(udev);
283 	return count;
284 }
285 
286 static DEVICE_ATTR(persist, S_IRUGO | S_IWUSR, show_persist, set_persist);
287 
288 static int add_persist_attributes(struct device *dev)
289 {
290 	int rc = 0;
291 
292 	if (is_usb_device(dev)) {
293 		struct usb_device *udev = to_usb_device(dev);
294 
295 		/* Hubs are automatically enabled for USB_PERSIST,
296 		 * no point in creating the attribute file.
297 		 */
298 		if (udev->descriptor.bDeviceClass != USB_CLASS_HUB)
299 			rc = sysfs_add_file_to_group(&dev->kobj,
300 					&dev_attr_persist.attr,
301 					power_group_name);
302 	}
303 	return rc;
304 }
305 
306 static void remove_persist_attributes(struct device *dev)
307 {
308 	sysfs_remove_file_from_group(&dev->kobj,
309 			&dev_attr_persist.attr,
310 			power_group_name);
311 }
312 #else
313 
314 #define add_persist_attributes(dev)	0
315 #define remove_persist_attributes(dev)	do {} while (0)
316 
317 #endif	/* CONFIG_PM */
318 
319 #ifdef	CONFIG_USB_SUSPEND
320 
321 static ssize_t
322 show_connected_duration(struct device *dev, struct device_attribute *attr,
323 		char *buf)
324 {
325 	struct usb_device *udev = to_usb_device(dev);
326 
327 	return sprintf(buf, "%u\n",
328 			jiffies_to_msecs(jiffies - udev->connect_time));
329 }
330 
331 static DEVICE_ATTR(connected_duration, S_IRUGO, show_connected_duration, NULL);
332 
333 /*
334  * If the device is resumed, the last time the device was suspended has
335  * been pre-subtracted from active_duration.  We add the current time to
336  * get the duration that the device was actually active.
337  *
338  * If the device is suspended, the active_duration is up-to-date.
339  */
340 static ssize_t
341 show_active_duration(struct device *dev, struct device_attribute *attr,
342 		char *buf)
343 {
344 	struct usb_device *udev = to_usb_device(dev);
345 	int duration;
346 
347 	if (udev->state != USB_STATE_SUSPENDED)
348 		duration = jiffies_to_msecs(jiffies + udev->active_duration);
349 	else
350 		duration = jiffies_to_msecs(udev->active_duration);
351 	return sprintf(buf, "%u\n", duration);
352 }
353 
354 static DEVICE_ATTR(active_duration, S_IRUGO, show_active_duration, NULL);
355 
356 static ssize_t
357 show_autosuspend(struct device *dev, struct device_attribute *attr, char *buf)
358 {
359 	return sprintf(buf, "%d\n", dev->power.autosuspend_delay / 1000);
360 }
361 
362 static ssize_t
363 set_autosuspend(struct device *dev, struct device_attribute *attr,
364 		const char *buf, size_t count)
365 {
366 	int value;
367 
368 	if (sscanf(buf, "%d", &value) != 1 || value >= INT_MAX/1000 ||
369 			value <= -INT_MAX/1000)
370 		return -EINVAL;
371 
372 	pm_runtime_set_autosuspend_delay(dev, value * 1000);
373 	return count;
374 }
375 
376 static DEVICE_ATTR(autosuspend, S_IRUGO | S_IWUSR,
377 		show_autosuspend, set_autosuspend);
378 
379 static const char on_string[] = "on";
380 static const char auto_string[] = "auto";
381 
382 static void warn_level(void) {
383 	static int level_warned;
384 
385 	if (!level_warned) {
386 		level_warned = 1;
387 		printk(KERN_WARNING "WARNING! power/level is deprecated; "
388 				"use power/control instead\n");
389 	}
390 }
391 
392 static ssize_t
393 show_level(struct device *dev, struct device_attribute *attr, char *buf)
394 {
395 	struct usb_device *udev = to_usb_device(dev);
396 	const char *p = auto_string;
397 
398 	warn_level();
399 	if (udev->state != USB_STATE_SUSPENDED && !udev->dev.power.runtime_auto)
400 		p = on_string;
401 	return sprintf(buf, "%s\n", p);
402 }
403 
404 static ssize_t
405 set_level(struct device *dev, struct device_attribute *attr,
406 		const char *buf, size_t count)
407 {
408 	struct usb_device *udev = to_usb_device(dev);
409 	int len = count;
410 	char *cp;
411 	int rc = count;
412 
413 	warn_level();
414 	cp = memchr(buf, '\n', count);
415 	if (cp)
416 		len = cp - buf;
417 
418 	usb_lock_device(udev);
419 
420 	if (len == sizeof on_string - 1 &&
421 			strncmp(buf, on_string, len) == 0)
422 		usb_disable_autosuspend(udev);
423 
424 	else if (len == sizeof auto_string - 1 &&
425 			strncmp(buf, auto_string, len) == 0)
426 		usb_enable_autosuspend(udev);
427 
428 	else
429 		rc = -EINVAL;
430 
431 	usb_unlock_device(udev);
432 	return rc;
433 }
434 
435 static DEVICE_ATTR(level, S_IRUGO | S_IWUSR, show_level, set_level);
436 
437 static ssize_t
438 show_usb2_hardware_lpm(struct device *dev, struct device_attribute *attr,
439 				char *buf)
440 {
441 	struct usb_device *udev = to_usb_device(dev);
442 	const char *p;
443 
444 	if (udev->usb2_hw_lpm_enabled == 1)
445 		p = "enabled";
446 	else
447 		p = "disabled";
448 
449 	return sprintf(buf, "%s\n", p);
450 }
451 
452 static ssize_t
453 set_usb2_hardware_lpm(struct device *dev, struct device_attribute *attr,
454 		const char *buf, size_t count)
455 {
456 	struct usb_device *udev = to_usb_device(dev);
457 	bool value;
458 	int ret;
459 
460 	usb_lock_device(udev);
461 
462 	ret = strtobool(buf, &value);
463 
464 	if (!ret)
465 		ret = usb_set_usb2_hardware_lpm(udev, value);
466 
467 	usb_unlock_device(udev);
468 
469 	if (!ret)
470 		return count;
471 
472 	return ret;
473 }
474 
475 static DEVICE_ATTR(usb2_hardware_lpm, S_IRUGO | S_IWUSR, show_usb2_hardware_lpm,
476 			set_usb2_hardware_lpm);
477 
478 static struct attribute *usb2_hardware_lpm_attr[] = {
479 	&dev_attr_usb2_hardware_lpm.attr,
480 	NULL,
481 };
482 static struct attribute_group usb2_hardware_lpm_attr_group = {
483 	.name	= power_group_name,
484 	.attrs	= usb2_hardware_lpm_attr,
485 };
486 
487 static struct attribute *power_attrs[] = {
488 	&dev_attr_autosuspend.attr,
489 	&dev_attr_level.attr,
490 	&dev_attr_connected_duration.attr,
491 	&dev_attr_active_duration.attr,
492 	NULL,
493 };
494 static struct attribute_group power_attr_group = {
495 	.name	= power_group_name,
496 	.attrs	= power_attrs,
497 };
498 
499 static int add_power_attributes(struct device *dev)
500 {
501 	int rc = 0;
502 
503 	if (is_usb_device(dev)) {
504 		struct usb_device *udev = to_usb_device(dev);
505 		rc = sysfs_merge_group(&dev->kobj, &power_attr_group);
506 		if (udev->usb2_hw_lpm_capable == 1)
507 			rc = sysfs_merge_group(&dev->kobj,
508 					&usb2_hardware_lpm_attr_group);
509 	}
510 
511 	return rc;
512 }
513 
514 static void remove_power_attributes(struct device *dev)
515 {
516 	sysfs_unmerge_group(&dev->kobj, &usb2_hardware_lpm_attr_group);
517 	sysfs_unmerge_group(&dev->kobj, &power_attr_group);
518 }
519 
520 #else
521 
522 #define add_power_attributes(dev)	0
523 #define remove_power_attributes(dev)	do {} while (0)
524 
525 #endif	/* CONFIG_USB_SUSPEND */
526 
527 
528 /* Descriptor fields */
529 #define usb_descriptor_attr_le16(field, format_string)			\
530 static ssize_t								\
531 show_##field(struct device *dev, struct device_attribute *attr,	\
532 		char *buf)						\
533 {									\
534 	struct usb_device *udev;					\
535 									\
536 	udev = to_usb_device(dev);					\
537 	return sprintf(buf, format_string, 				\
538 			le16_to_cpu(udev->descriptor.field));		\
539 }									\
540 static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);
541 
542 usb_descriptor_attr_le16(idVendor, "%04x\n")
543 usb_descriptor_attr_le16(idProduct, "%04x\n")
544 usb_descriptor_attr_le16(bcdDevice, "%04x\n")
545 
546 #define usb_descriptor_attr(field, format_string)			\
547 static ssize_t								\
548 show_##field(struct device *dev, struct device_attribute *attr,	\
549 		char *buf)						\
550 {									\
551 	struct usb_device *udev;					\
552 									\
553 	udev = to_usb_device(dev);					\
554 	return sprintf(buf, format_string, udev->descriptor.field);	\
555 }									\
556 static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);
557 
558 usb_descriptor_attr(bDeviceClass, "%02x\n")
559 usb_descriptor_attr(bDeviceSubClass, "%02x\n")
560 usb_descriptor_attr(bDeviceProtocol, "%02x\n")
561 usb_descriptor_attr(bNumConfigurations, "%d\n")
562 usb_descriptor_attr(bMaxPacketSize0, "%d\n")
563 
564 
565 
566 /* show if the device is authorized (1) or not (0) */
567 static ssize_t usb_dev_authorized_show(struct device *dev,
568 				       struct device_attribute *attr,
569 				       char *buf)
570 {
571 	struct usb_device *usb_dev = to_usb_device(dev);
572 	return snprintf(buf, PAGE_SIZE, "%u\n", usb_dev->authorized);
573 }
574 
575 
576 /*
577  * Authorize a device to be used in the system
578  *
579  * Writing a 0 deauthorizes the device, writing a 1 authorizes it.
580  */
581 static ssize_t usb_dev_authorized_store(struct device *dev,
582 					struct device_attribute *attr,
583 					const char *buf, size_t size)
584 {
585 	ssize_t result;
586 	struct usb_device *usb_dev = to_usb_device(dev);
587 	unsigned val;
588 	result = sscanf(buf, "%u\n", &val);
589 	if (result != 1)
590 		result = -EINVAL;
591 	else if (val == 0)
592 		result = usb_deauthorize_device(usb_dev);
593 	else
594 		result = usb_authorize_device(usb_dev);
595 	return result < 0? result : size;
596 }
597 
598 static DEVICE_ATTR(authorized, 0644,
599 	    usb_dev_authorized_show, usb_dev_authorized_store);
600 
601 /* "Safely remove a device" */
602 static ssize_t usb_remove_store(struct device *dev,
603 		struct device_attribute *attr,
604 		const char *buf, size_t count)
605 {
606 	struct usb_device *udev = to_usb_device(dev);
607 	int rc = 0;
608 
609 	usb_lock_device(udev);
610 	if (udev->state != USB_STATE_NOTATTACHED) {
611 
612 		/* To avoid races, first unconfigure and then remove */
613 		usb_set_configuration(udev, -1);
614 		rc = usb_remove_device(udev);
615 	}
616 	if (rc == 0)
617 		rc = count;
618 	usb_unlock_device(udev);
619 	return rc;
620 }
621 static DEVICE_ATTR(remove, 0200, NULL, usb_remove_store);
622 
623 
624 static struct attribute *dev_attrs[] = {
625 	/* current configuration's attributes */
626 	&dev_attr_configuration.attr,
627 	&dev_attr_bNumInterfaces.attr,
628 	&dev_attr_bConfigurationValue.attr,
629 	&dev_attr_bmAttributes.attr,
630 	&dev_attr_bMaxPower.attr,
631 	/* device attributes */
632 	&dev_attr_urbnum.attr,
633 	&dev_attr_idVendor.attr,
634 	&dev_attr_idProduct.attr,
635 	&dev_attr_bcdDevice.attr,
636 	&dev_attr_bDeviceClass.attr,
637 	&dev_attr_bDeviceSubClass.attr,
638 	&dev_attr_bDeviceProtocol.attr,
639 	&dev_attr_bNumConfigurations.attr,
640 	&dev_attr_bMaxPacketSize0.attr,
641 	&dev_attr_speed.attr,
642 	&dev_attr_busnum.attr,
643 	&dev_attr_devnum.attr,
644 	&dev_attr_devpath.attr,
645 	&dev_attr_version.attr,
646 	&dev_attr_maxchild.attr,
647 	&dev_attr_quirks.attr,
648 	&dev_attr_avoid_reset_quirk.attr,
649 	&dev_attr_authorized.attr,
650 	&dev_attr_remove.attr,
651 	&dev_attr_removable.attr,
652 	NULL,
653 };
654 static struct attribute_group dev_attr_grp = {
655 	.attrs = dev_attrs,
656 };
657 
658 /* When modifying this list, be sure to modify dev_string_attrs_are_visible()
659  * accordingly.
660  */
661 static struct attribute *dev_string_attrs[] = {
662 	&dev_attr_manufacturer.attr,
663 	&dev_attr_product.attr,
664 	&dev_attr_serial.attr,
665 	NULL
666 };
667 
668 static umode_t dev_string_attrs_are_visible(struct kobject *kobj,
669 		struct attribute *a, int n)
670 {
671 	struct device *dev = container_of(kobj, struct device, kobj);
672 	struct usb_device *udev = to_usb_device(dev);
673 
674 	if (a == &dev_attr_manufacturer.attr) {
675 		if (udev->manufacturer == NULL)
676 			return 0;
677 	} else if (a == &dev_attr_product.attr) {
678 		if (udev->product == NULL)
679 			return 0;
680 	} else if (a == &dev_attr_serial.attr) {
681 		if (udev->serial == NULL)
682 			return 0;
683 	}
684 	return a->mode;
685 }
686 
687 static struct attribute_group dev_string_attr_grp = {
688 	.attrs =	dev_string_attrs,
689 	.is_visible =	dev_string_attrs_are_visible,
690 };
691 
692 const struct attribute_group *usb_device_groups[] = {
693 	&dev_attr_grp,
694 	&dev_string_attr_grp,
695 	NULL
696 };
697 
698 /* Binary descriptors */
699 
700 static ssize_t
701 read_descriptors(struct file *filp, struct kobject *kobj,
702 		struct bin_attribute *attr,
703 		char *buf, loff_t off, size_t count)
704 {
705 	struct device *dev = container_of(kobj, struct device, kobj);
706 	struct usb_device *udev = to_usb_device(dev);
707 	size_t nleft = count;
708 	size_t srclen, n;
709 	int cfgno;
710 	void *src;
711 
712 	/* The binary attribute begins with the device descriptor.
713 	 * Following that are the raw descriptor entries for all the
714 	 * configurations (config plus subsidiary descriptors).
715 	 */
716 	for (cfgno = -1; cfgno < udev->descriptor.bNumConfigurations &&
717 			nleft > 0; ++cfgno) {
718 		if (cfgno < 0) {
719 			src = &udev->descriptor;
720 			srclen = sizeof(struct usb_device_descriptor);
721 		} else {
722 			src = udev->rawdescriptors[cfgno];
723 			srclen = __le16_to_cpu(udev->config[cfgno].desc.
724 					wTotalLength);
725 		}
726 		if (off < srclen) {
727 			n = min(nleft, srclen - (size_t) off);
728 			memcpy(buf, src + off, n);
729 			nleft -= n;
730 			buf += n;
731 			off = 0;
732 		} else {
733 			off -= srclen;
734 		}
735 	}
736 	return count - nleft;
737 }
738 
739 static struct bin_attribute dev_bin_attr_descriptors = {
740 	.attr = {.name = "descriptors", .mode = 0444},
741 	.read = read_descriptors,
742 	.size = 18 + 65535,	/* dev descr + max-size raw descriptor */
743 };
744 
745 int usb_create_sysfs_dev_files(struct usb_device *udev)
746 {
747 	struct device *dev = &udev->dev;
748 	int retval;
749 
750 	retval = device_create_bin_file(dev, &dev_bin_attr_descriptors);
751 	if (retval)
752 		goto error;
753 
754 	retval = add_persist_attributes(dev);
755 	if (retval)
756 		goto error;
757 
758 	retval = add_power_attributes(dev);
759 	if (retval)
760 		goto error;
761 	return retval;
762 error:
763 	usb_remove_sysfs_dev_files(udev);
764 	return retval;
765 }
766 
767 void usb_remove_sysfs_dev_files(struct usb_device *udev)
768 {
769 	struct device *dev = &udev->dev;
770 
771 	remove_power_attributes(dev);
772 	remove_persist_attributes(dev);
773 	device_remove_bin_file(dev, &dev_bin_attr_descriptors);
774 }
775 
776 /* Interface Accociation Descriptor fields */
777 #define usb_intf_assoc_attr(field, format_string)			\
778 static ssize_t								\
779 show_iad_##field(struct device *dev, struct device_attribute *attr,	\
780 		char *buf)						\
781 {									\
782 	struct usb_interface *intf = to_usb_interface(dev);		\
783 									\
784 	return sprintf(buf, format_string,				\
785 			intf->intf_assoc->field); 			\
786 }									\
787 static DEVICE_ATTR(iad_##field, S_IRUGO, show_iad_##field, NULL);
788 
789 usb_intf_assoc_attr(bFirstInterface, "%02x\n")
790 usb_intf_assoc_attr(bInterfaceCount, "%02d\n")
791 usb_intf_assoc_attr(bFunctionClass, "%02x\n")
792 usb_intf_assoc_attr(bFunctionSubClass, "%02x\n")
793 usb_intf_assoc_attr(bFunctionProtocol, "%02x\n")
794 
795 /* Interface fields */
796 #define usb_intf_attr(field, format_string)				\
797 static ssize_t								\
798 show_##field(struct device *dev, struct device_attribute *attr,	\
799 		char *buf)						\
800 {									\
801 	struct usb_interface *intf = to_usb_interface(dev);		\
802 									\
803 	return sprintf(buf, format_string,				\
804 			intf->cur_altsetting->desc.field); 		\
805 }									\
806 static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);
807 
808 usb_intf_attr(bInterfaceNumber, "%02x\n")
809 usb_intf_attr(bAlternateSetting, "%2d\n")
810 usb_intf_attr(bNumEndpoints, "%02x\n")
811 usb_intf_attr(bInterfaceClass, "%02x\n")
812 usb_intf_attr(bInterfaceSubClass, "%02x\n")
813 usb_intf_attr(bInterfaceProtocol, "%02x\n")
814 
815 static ssize_t show_interface_string(struct device *dev,
816 		struct device_attribute *attr, char *buf)
817 {
818 	struct usb_interface *intf;
819 	char *string;
820 
821 	intf = to_usb_interface(dev);
822 	string = intf->cur_altsetting->string;
823 	barrier();		/* The altsetting might change! */
824 
825 	if (!string)
826 		return 0;
827 	return sprintf(buf, "%s\n", string);
828 }
829 static DEVICE_ATTR(interface, S_IRUGO, show_interface_string, NULL);
830 
831 static ssize_t show_modalias(struct device *dev,
832 		struct device_attribute *attr, char *buf)
833 {
834 	struct usb_interface *intf;
835 	struct usb_device *udev;
836 	struct usb_host_interface *alt;
837 
838 	intf = to_usb_interface(dev);
839 	udev = interface_to_usbdev(intf);
840 	alt = intf->cur_altsetting;
841 
842 	return sprintf(buf, "usb:v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02X"
843 			"ic%02Xisc%02Xip%02X\n",
844 			le16_to_cpu(udev->descriptor.idVendor),
845 			le16_to_cpu(udev->descriptor.idProduct),
846 			le16_to_cpu(udev->descriptor.bcdDevice),
847 			udev->descriptor.bDeviceClass,
848 			udev->descriptor.bDeviceSubClass,
849 			udev->descriptor.bDeviceProtocol,
850 			alt->desc.bInterfaceClass,
851 			alt->desc.bInterfaceSubClass,
852 			alt->desc.bInterfaceProtocol);
853 }
854 static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL);
855 
856 static ssize_t show_supports_autosuspend(struct device *dev,
857 		struct device_attribute *attr, char *buf)
858 {
859 	struct usb_interface *intf;
860 	struct usb_device *udev;
861 	int ret;
862 
863 	intf = to_usb_interface(dev);
864 	udev = interface_to_usbdev(intf);
865 
866 	usb_lock_device(udev);
867 	/* Devices will be autosuspended even when an interface isn't claimed */
868 	if (!intf->dev.driver ||
869 			to_usb_driver(intf->dev.driver)->supports_autosuspend)
870 		ret = sprintf(buf, "%u\n", 1);
871 	else
872 		ret = sprintf(buf, "%u\n", 0);
873 	usb_unlock_device(udev);
874 
875 	return ret;
876 }
877 static DEVICE_ATTR(supports_autosuspend, S_IRUGO, show_supports_autosuspend, NULL);
878 
879 static struct attribute *intf_attrs[] = {
880 	&dev_attr_bInterfaceNumber.attr,
881 	&dev_attr_bAlternateSetting.attr,
882 	&dev_attr_bNumEndpoints.attr,
883 	&dev_attr_bInterfaceClass.attr,
884 	&dev_attr_bInterfaceSubClass.attr,
885 	&dev_attr_bInterfaceProtocol.attr,
886 	&dev_attr_modalias.attr,
887 	&dev_attr_supports_autosuspend.attr,
888 	NULL,
889 };
890 static struct attribute_group intf_attr_grp = {
891 	.attrs = intf_attrs,
892 };
893 
894 static struct attribute *intf_assoc_attrs[] = {
895 	&dev_attr_iad_bFirstInterface.attr,
896 	&dev_attr_iad_bInterfaceCount.attr,
897 	&dev_attr_iad_bFunctionClass.attr,
898 	&dev_attr_iad_bFunctionSubClass.attr,
899 	&dev_attr_iad_bFunctionProtocol.attr,
900 	NULL,
901 };
902 
903 static umode_t intf_assoc_attrs_are_visible(struct kobject *kobj,
904 		struct attribute *a, int n)
905 {
906 	struct device *dev = container_of(kobj, struct device, kobj);
907 	struct usb_interface *intf = to_usb_interface(dev);
908 
909 	if (intf->intf_assoc == NULL)
910 		return 0;
911 	return a->mode;
912 }
913 
914 static struct attribute_group intf_assoc_attr_grp = {
915 	.attrs =	intf_assoc_attrs,
916 	.is_visible =	intf_assoc_attrs_are_visible,
917 };
918 
919 const struct attribute_group *usb_interface_groups[] = {
920 	&intf_attr_grp,
921 	&intf_assoc_attr_grp,
922 	NULL
923 };
924 
925 void usb_create_sysfs_intf_files(struct usb_interface *intf)
926 {
927 	struct usb_device *udev = interface_to_usbdev(intf);
928 	struct usb_host_interface *alt = intf->cur_altsetting;
929 
930 	if (intf->sysfs_files_created || intf->unregistering)
931 		return;
932 
933 	if (!alt->string && !(udev->quirks & USB_QUIRK_CONFIG_INTF_STRINGS))
934 		alt->string = usb_cache_string(udev, alt->desc.iInterface);
935 	if (alt->string && device_create_file(&intf->dev, &dev_attr_interface))
936 		;	/* We don't actually care if the function fails. */
937 	intf->sysfs_files_created = 1;
938 }
939 
940 void usb_remove_sysfs_intf_files(struct usb_interface *intf)
941 {
942 	if (!intf->sysfs_files_created)
943 		return;
944 
945 	device_remove_file(&intf->dev, &dev_attr_interface);
946 	intf->sysfs_files_created = 0;
947 }
948