xref: /linux/drivers/usb/core/sysfs.c (revision 273b281fa22c293963ee3e6eec418f5dda2dbc83)
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 									\
86 	udev = to_usb_device(dev);					\
87 	return sprintf(buf, "%s\n", udev->name);			\
88 }									\
89 static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL);
90 
91 usb_string_attr(product);
92 usb_string_attr(manufacturer);
93 usb_string_attr(serial);
94 
95 static ssize_t
96 show_speed(struct device *dev, struct device_attribute *attr, char *buf)
97 {
98 	struct usb_device *udev;
99 	char *speed;
100 
101 	udev = to_usb_device(dev);
102 
103 	switch (udev->speed) {
104 	case USB_SPEED_LOW:
105 		speed = "1.5";
106 		break;
107 	case USB_SPEED_UNKNOWN:
108 	case USB_SPEED_FULL:
109 		speed = "12";
110 		break;
111 	case USB_SPEED_HIGH:
112 		speed = "480";
113 		break;
114 	default:
115 		speed = "unknown";
116 	}
117 	return sprintf(buf, "%s\n", speed);
118 }
119 static DEVICE_ATTR(speed, S_IRUGO, show_speed, NULL);
120 
121 static ssize_t
122 show_busnum(struct device *dev, struct device_attribute *attr, char *buf)
123 {
124 	struct usb_device *udev;
125 
126 	udev = to_usb_device(dev);
127 	return sprintf(buf, "%d\n", udev->bus->busnum);
128 }
129 static DEVICE_ATTR(busnum, S_IRUGO, show_busnum, NULL);
130 
131 static ssize_t
132 show_devnum(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->devnum);
138 }
139 static DEVICE_ATTR(devnum, S_IRUGO, show_devnum, NULL);
140 
141 static ssize_t
142 show_devpath(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, "%s\n", udev->devpath);
148 }
149 static DEVICE_ATTR(devpath, S_IRUGO, show_devpath, NULL);
150 
151 static ssize_t
152 show_version(struct device *dev, struct device_attribute *attr, char *buf)
153 {
154 	struct usb_device *udev;
155 	u16 bcdUSB;
156 
157 	udev = to_usb_device(dev);
158 	bcdUSB = le16_to_cpu(udev->descriptor.bcdUSB);
159 	return sprintf(buf, "%2x.%02x\n", bcdUSB >> 8, bcdUSB & 0xff);
160 }
161 static DEVICE_ATTR(version, S_IRUGO, show_version, NULL);
162 
163 static ssize_t
164 show_maxchild(struct device *dev, struct device_attribute *attr, char *buf)
165 {
166 	struct usb_device *udev;
167 
168 	udev = to_usb_device(dev);
169 	return sprintf(buf, "%d\n", udev->maxchild);
170 }
171 static DEVICE_ATTR(maxchild, S_IRUGO, show_maxchild, NULL);
172 
173 static ssize_t
174 show_quirks(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, "0x%x\n", udev->quirks);
180 }
181 static DEVICE_ATTR(quirks, S_IRUGO, show_quirks, NULL);
182 
183 static ssize_t
184 show_urbnum(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, "%d\n", atomic_read(&udev->urbnum));
190 }
191 static DEVICE_ATTR(urbnum, S_IRUGO, show_urbnum, NULL);
192 
193 
194 #ifdef	CONFIG_PM
195 
196 static const char power_group[] = "power";
197 
198 static ssize_t
199 show_persist(struct device *dev, struct device_attribute *attr, char *buf)
200 {
201 	struct usb_device *udev = to_usb_device(dev);
202 
203 	return sprintf(buf, "%d\n", udev->persist_enabled);
204 }
205 
206 static ssize_t
207 set_persist(struct device *dev, struct device_attribute *attr,
208 		const char *buf, size_t count)
209 {
210 	struct usb_device *udev = to_usb_device(dev);
211 	int value;
212 
213 	/* Hubs are always enabled for USB_PERSIST */
214 	if (udev->descriptor.bDeviceClass == USB_CLASS_HUB)
215 		return -EPERM;
216 
217 	if (sscanf(buf, "%d", &value) != 1)
218 		return -EINVAL;
219 	usb_pm_lock(udev);
220 	udev->persist_enabled = !!value;
221 	usb_pm_unlock(udev);
222 	return count;
223 }
224 
225 static DEVICE_ATTR(persist, S_IRUGO | S_IWUSR, show_persist, set_persist);
226 
227 static int add_persist_attributes(struct device *dev)
228 {
229 	int rc = 0;
230 
231 	if (is_usb_device(dev)) {
232 		struct usb_device *udev = to_usb_device(dev);
233 
234 		/* Hubs are automatically enabled for USB_PERSIST,
235 		 * no point in creating the attribute file.
236 		 */
237 		if (udev->descriptor.bDeviceClass != USB_CLASS_HUB)
238 			rc = sysfs_add_file_to_group(&dev->kobj,
239 					&dev_attr_persist.attr,
240 					power_group);
241 	}
242 	return rc;
243 }
244 
245 static void remove_persist_attributes(struct device *dev)
246 {
247 	sysfs_remove_file_from_group(&dev->kobj,
248 			&dev_attr_persist.attr,
249 			power_group);
250 }
251 #else
252 
253 #define add_persist_attributes(dev)	0
254 #define remove_persist_attributes(dev)	do {} while (0)
255 
256 #endif	/* CONFIG_PM */
257 
258 #ifdef	CONFIG_USB_SUSPEND
259 
260 static ssize_t
261 show_connected_duration(struct device *dev, struct device_attribute *attr,
262 		char *buf)
263 {
264 	struct usb_device *udev = to_usb_device(dev);
265 
266 	return sprintf(buf, "%u\n",
267 			jiffies_to_msecs(jiffies - udev->connect_time));
268 }
269 
270 static DEVICE_ATTR(connected_duration, S_IRUGO, show_connected_duration, NULL);
271 
272 /*
273  * If the device is resumed, the last time the device was suspended has
274  * been pre-subtracted from active_duration.  We add the current time to
275  * get the duration that the device was actually active.
276  *
277  * If the device is suspended, the active_duration is up-to-date.
278  */
279 static ssize_t
280 show_active_duration(struct device *dev, struct device_attribute *attr,
281 		char *buf)
282 {
283 	struct usb_device *udev = to_usb_device(dev);
284 	int duration;
285 
286 	if (udev->state != USB_STATE_SUSPENDED)
287 		duration = jiffies_to_msecs(jiffies + udev->active_duration);
288 	else
289 		duration = jiffies_to_msecs(udev->active_duration);
290 	return sprintf(buf, "%u\n", duration);
291 }
292 
293 static DEVICE_ATTR(active_duration, S_IRUGO, show_active_duration, NULL);
294 
295 static ssize_t
296 show_autosuspend(struct device *dev, struct device_attribute *attr, char *buf)
297 {
298 	struct usb_device *udev = to_usb_device(dev);
299 
300 	return sprintf(buf, "%d\n", udev->autosuspend_delay / HZ);
301 }
302 
303 static ssize_t
304 set_autosuspend(struct device *dev, struct device_attribute *attr,
305 		const char *buf, size_t count)
306 {
307 	struct usb_device *udev = to_usb_device(dev);
308 	int value;
309 
310 	if (sscanf(buf, "%d", &value) != 1 || value >= INT_MAX/HZ ||
311 			value <= - INT_MAX/HZ)
312 		return -EINVAL;
313 	value *= HZ;
314 
315 	udev->autosuspend_delay = value;
316 	if (value >= 0)
317 		usb_try_autosuspend_device(udev);
318 	else {
319 		if (usb_autoresume_device(udev) == 0)
320 			usb_autosuspend_device(udev);
321 	}
322 	return count;
323 }
324 
325 static DEVICE_ATTR(autosuspend, S_IRUGO | S_IWUSR,
326 		show_autosuspend, set_autosuspend);
327 
328 static const char on_string[] = "on";
329 static const char auto_string[] = "auto";
330 
331 static ssize_t
332 show_level(struct device *dev, struct device_attribute *attr, char *buf)
333 {
334 	struct usb_device *udev = to_usb_device(dev);
335 	const char *p = auto_string;
336 
337 	if (udev->state != USB_STATE_SUSPENDED && udev->autosuspend_disabled)
338 		p = on_string;
339 	return sprintf(buf, "%s\n", p);
340 }
341 
342 static ssize_t
343 set_level(struct device *dev, struct device_attribute *attr,
344 		const char *buf, size_t count)
345 {
346 	struct usb_device *udev = to_usb_device(dev);
347 	int len = count;
348 	char *cp;
349 	int rc = 0;
350 	int old_autosuspend_disabled;
351 
352 	cp = memchr(buf, '\n', count);
353 	if (cp)
354 		len = cp - buf;
355 
356 	usb_lock_device(udev);
357 	old_autosuspend_disabled = udev->autosuspend_disabled;
358 
359 	/* Setting the flags without calling usb_pm_lock is a subject to
360 	 * races, but who cares...
361 	 */
362 	if (len == sizeof on_string - 1 &&
363 			strncmp(buf, on_string, len) == 0) {
364 		udev->autosuspend_disabled = 1;
365 		rc = usb_external_resume_device(udev, PMSG_USER_RESUME);
366 
367 	} else if (len == sizeof auto_string - 1 &&
368 			strncmp(buf, auto_string, len) == 0) {
369 		udev->autosuspend_disabled = 0;
370 		rc = usb_external_resume_device(udev, PMSG_USER_RESUME);
371 
372 	} else
373 		rc = -EINVAL;
374 
375 	if (rc)
376 		udev->autosuspend_disabled = old_autosuspend_disabled;
377 	usb_unlock_device(udev);
378 	return (rc < 0 ? rc : count);
379 }
380 
381 static DEVICE_ATTR(level, S_IRUGO | S_IWUSR, show_level, set_level);
382 
383 static int add_power_attributes(struct device *dev)
384 {
385 	int rc = 0;
386 
387 	if (is_usb_device(dev)) {
388 		rc = sysfs_add_file_to_group(&dev->kobj,
389 				&dev_attr_autosuspend.attr,
390 				power_group);
391 		if (rc == 0)
392 			rc = sysfs_add_file_to_group(&dev->kobj,
393 					&dev_attr_level.attr,
394 					power_group);
395 		if (rc == 0)
396 			rc = sysfs_add_file_to_group(&dev->kobj,
397 					&dev_attr_connected_duration.attr,
398 					power_group);
399 		if (rc == 0)
400 			rc = sysfs_add_file_to_group(&dev->kobj,
401 					&dev_attr_active_duration.attr,
402 					power_group);
403 	}
404 	return rc;
405 }
406 
407 static void remove_power_attributes(struct device *dev)
408 {
409 	sysfs_remove_file_from_group(&dev->kobj,
410 			&dev_attr_active_duration.attr,
411 			power_group);
412 	sysfs_remove_file_from_group(&dev->kobj,
413 			&dev_attr_connected_duration.attr,
414 			power_group);
415 	sysfs_remove_file_from_group(&dev->kobj,
416 			&dev_attr_level.attr,
417 			power_group);
418 	sysfs_remove_file_from_group(&dev->kobj,
419 			&dev_attr_autosuspend.attr,
420 			power_group);
421 }
422 
423 #else
424 
425 #define add_power_attributes(dev)	0
426 #define remove_power_attributes(dev)	do {} while (0)
427 
428 #endif	/* CONFIG_USB_SUSPEND */
429 
430 
431 /* Descriptor fields */
432 #define usb_descriptor_attr_le16(field, format_string)			\
433 static ssize_t								\
434 show_##field(struct device *dev, struct device_attribute *attr,	\
435 		char *buf)						\
436 {									\
437 	struct usb_device *udev;					\
438 									\
439 	udev = to_usb_device(dev);					\
440 	return sprintf(buf, format_string, 				\
441 			le16_to_cpu(udev->descriptor.field));		\
442 }									\
443 static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);
444 
445 usb_descriptor_attr_le16(idVendor, "%04x\n")
446 usb_descriptor_attr_le16(idProduct, "%04x\n")
447 usb_descriptor_attr_le16(bcdDevice, "%04x\n")
448 
449 #define usb_descriptor_attr(field, format_string)			\
450 static ssize_t								\
451 show_##field(struct device *dev, struct device_attribute *attr,	\
452 		char *buf)						\
453 {									\
454 	struct usb_device *udev;					\
455 									\
456 	udev = to_usb_device(dev);					\
457 	return sprintf(buf, format_string, udev->descriptor.field);	\
458 }									\
459 static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);
460 
461 usb_descriptor_attr(bDeviceClass, "%02x\n")
462 usb_descriptor_attr(bDeviceSubClass, "%02x\n")
463 usb_descriptor_attr(bDeviceProtocol, "%02x\n")
464 usb_descriptor_attr(bNumConfigurations, "%d\n")
465 usb_descriptor_attr(bMaxPacketSize0, "%d\n")
466 
467 
468 
469 /* show if the device is authorized (1) or not (0) */
470 static ssize_t usb_dev_authorized_show(struct device *dev,
471 				       struct device_attribute *attr,
472 				       char *buf)
473 {
474 	struct usb_device *usb_dev = to_usb_device(dev);
475 	return snprintf(buf, PAGE_SIZE, "%u\n", usb_dev->authorized);
476 }
477 
478 
479 /*
480  * Authorize a device to be used in the system
481  *
482  * Writing a 0 deauthorizes the device, writing a 1 authorizes it.
483  */
484 static ssize_t usb_dev_authorized_store(struct device *dev,
485 					struct device_attribute *attr,
486 					const char *buf, size_t size)
487 {
488 	ssize_t result;
489 	struct usb_device *usb_dev = to_usb_device(dev);
490 	unsigned val;
491 	result = sscanf(buf, "%u\n", &val);
492 	if (result != 1)
493 		result = -EINVAL;
494 	else if (val == 0)
495 		result = usb_deauthorize_device(usb_dev);
496 	else
497 		result = usb_authorize_device(usb_dev);
498 	return result < 0? result : size;
499 }
500 
501 static DEVICE_ATTR(authorized, 0644,
502 	    usb_dev_authorized_show, usb_dev_authorized_store);
503 
504 /* "Safely remove a device" */
505 static ssize_t usb_remove_store(struct device *dev,
506 		struct device_attribute *attr,
507 		const char *buf, size_t count)
508 {
509 	struct usb_device *udev = to_usb_device(dev);
510 	int rc = 0;
511 
512 	usb_lock_device(udev);
513 	if (udev->state != USB_STATE_NOTATTACHED) {
514 
515 		/* To avoid races, first unconfigure and then remove */
516 		usb_set_configuration(udev, -1);
517 		rc = usb_remove_device(udev);
518 	}
519 	if (rc == 0)
520 		rc = count;
521 	usb_unlock_device(udev);
522 	return rc;
523 }
524 static DEVICE_ATTR(remove, 0200, NULL, usb_remove_store);
525 
526 
527 static struct attribute *dev_attrs[] = {
528 	/* current configuration's attributes */
529 	&dev_attr_configuration.attr,
530 	&dev_attr_bNumInterfaces.attr,
531 	&dev_attr_bConfigurationValue.attr,
532 	&dev_attr_bmAttributes.attr,
533 	&dev_attr_bMaxPower.attr,
534 	/* device attributes */
535 	&dev_attr_urbnum.attr,
536 	&dev_attr_idVendor.attr,
537 	&dev_attr_idProduct.attr,
538 	&dev_attr_bcdDevice.attr,
539 	&dev_attr_bDeviceClass.attr,
540 	&dev_attr_bDeviceSubClass.attr,
541 	&dev_attr_bDeviceProtocol.attr,
542 	&dev_attr_bNumConfigurations.attr,
543 	&dev_attr_bMaxPacketSize0.attr,
544 	&dev_attr_speed.attr,
545 	&dev_attr_busnum.attr,
546 	&dev_attr_devnum.attr,
547 	&dev_attr_devpath.attr,
548 	&dev_attr_version.attr,
549 	&dev_attr_maxchild.attr,
550 	&dev_attr_quirks.attr,
551 	&dev_attr_authorized.attr,
552 	&dev_attr_remove.attr,
553 	NULL,
554 };
555 static struct attribute_group dev_attr_grp = {
556 	.attrs = dev_attrs,
557 };
558 
559 /* When modifying this list, be sure to modify dev_string_attrs_are_visible()
560  * accordingly.
561  */
562 static struct attribute *dev_string_attrs[] = {
563 	&dev_attr_manufacturer.attr,
564 	&dev_attr_product.attr,
565 	&dev_attr_serial.attr,
566 	NULL
567 };
568 
569 static mode_t dev_string_attrs_are_visible(struct kobject *kobj,
570 		struct attribute *a, int n)
571 {
572 	struct device *dev = container_of(kobj, struct device, kobj);
573 	struct usb_device *udev = to_usb_device(dev);
574 
575 	if (a == &dev_attr_manufacturer.attr) {
576 		if (udev->manufacturer == NULL)
577 			return 0;
578 	} else if (a == &dev_attr_product.attr) {
579 		if (udev->product == NULL)
580 			return 0;
581 	} else if (a == &dev_attr_serial.attr) {
582 		if (udev->serial == NULL)
583 			return 0;
584 	}
585 	return a->mode;
586 }
587 
588 static struct attribute_group dev_string_attr_grp = {
589 	.attrs =	dev_string_attrs,
590 	.is_visible =	dev_string_attrs_are_visible,
591 };
592 
593 const struct attribute_group *usb_device_groups[] = {
594 	&dev_attr_grp,
595 	&dev_string_attr_grp,
596 	NULL
597 };
598 
599 /* Binary descriptors */
600 
601 static ssize_t
602 read_descriptors(struct kobject *kobj, struct bin_attribute *attr,
603 		char *buf, loff_t off, size_t count)
604 {
605 	struct device *dev = container_of(kobj, struct device, kobj);
606 	struct usb_device *udev = to_usb_device(dev);
607 	size_t nleft = count;
608 	size_t srclen, n;
609 	int cfgno;
610 	void *src;
611 
612 	/* The binary attribute begins with the device descriptor.
613 	 * Following that are the raw descriptor entries for all the
614 	 * configurations (config plus subsidiary descriptors).
615 	 */
616 	for (cfgno = -1; cfgno < udev->descriptor.bNumConfigurations &&
617 			nleft > 0; ++cfgno) {
618 		if (cfgno < 0) {
619 			src = &udev->descriptor;
620 			srclen = sizeof(struct usb_device_descriptor);
621 		} else {
622 			src = udev->rawdescriptors[cfgno];
623 			srclen = __le16_to_cpu(udev->config[cfgno].desc.
624 					wTotalLength);
625 		}
626 		if (off < srclen) {
627 			n = min(nleft, srclen - (size_t) off);
628 			memcpy(buf, src + off, n);
629 			nleft -= n;
630 			buf += n;
631 			off = 0;
632 		} else {
633 			off -= srclen;
634 		}
635 	}
636 	return count - nleft;
637 }
638 
639 static struct bin_attribute dev_bin_attr_descriptors = {
640 	.attr = {.name = "descriptors", .mode = 0444},
641 	.read = read_descriptors,
642 	.size = 18 + 65535,	/* dev descr + max-size raw descriptor */
643 };
644 
645 int usb_create_sysfs_dev_files(struct usb_device *udev)
646 {
647 	struct device *dev = &udev->dev;
648 	int retval;
649 
650 	retval = device_create_bin_file(dev, &dev_bin_attr_descriptors);
651 	if (retval)
652 		goto error;
653 
654 	retval = add_persist_attributes(dev);
655 	if (retval)
656 		goto error;
657 
658 	retval = add_power_attributes(dev);
659 	if (retval)
660 		goto error;
661 	return retval;
662 error:
663 	usb_remove_sysfs_dev_files(udev);
664 	return retval;
665 }
666 
667 void usb_remove_sysfs_dev_files(struct usb_device *udev)
668 {
669 	struct device *dev = &udev->dev;
670 
671 	remove_power_attributes(dev);
672 	remove_persist_attributes(dev);
673 	device_remove_bin_file(dev, &dev_bin_attr_descriptors);
674 }
675 
676 /* Interface Accociation Descriptor fields */
677 #define usb_intf_assoc_attr(field, format_string)			\
678 static ssize_t								\
679 show_iad_##field(struct device *dev, struct device_attribute *attr,	\
680 		char *buf)						\
681 {									\
682 	struct usb_interface *intf = to_usb_interface(dev);		\
683 									\
684 	return sprintf(buf, format_string,				\
685 			intf->intf_assoc->field); 			\
686 }									\
687 static DEVICE_ATTR(iad_##field, S_IRUGO, show_iad_##field, NULL);
688 
689 usb_intf_assoc_attr(bFirstInterface, "%02x\n")
690 usb_intf_assoc_attr(bInterfaceCount, "%02d\n")
691 usb_intf_assoc_attr(bFunctionClass, "%02x\n")
692 usb_intf_assoc_attr(bFunctionSubClass, "%02x\n")
693 usb_intf_assoc_attr(bFunctionProtocol, "%02x\n")
694 
695 /* Interface fields */
696 #define usb_intf_attr(field, format_string)				\
697 static ssize_t								\
698 show_##field(struct device *dev, struct device_attribute *attr,	\
699 		char *buf)						\
700 {									\
701 	struct usb_interface *intf = to_usb_interface(dev);		\
702 									\
703 	return sprintf(buf, format_string,				\
704 			intf->cur_altsetting->desc.field); 		\
705 }									\
706 static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);
707 
708 usb_intf_attr(bInterfaceNumber, "%02x\n")
709 usb_intf_attr(bAlternateSetting, "%2d\n")
710 usb_intf_attr(bNumEndpoints, "%02x\n")
711 usb_intf_attr(bInterfaceClass, "%02x\n")
712 usb_intf_attr(bInterfaceSubClass, "%02x\n")
713 usb_intf_attr(bInterfaceProtocol, "%02x\n")
714 
715 static ssize_t show_interface_string(struct device *dev,
716 		struct device_attribute *attr, char *buf)
717 {
718 	struct usb_interface *intf;
719 	char *string;
720 
721 	intf = to_usb_interface(dev);
722 	string = intf->cur_altsetting->string;
723 	barrier();		/* The altsetting might change! */
724 
725 	if (!string)
726 		return 0;
727 	return sprintf(buf, "%s\n", string);
728 }
729 static DEVICE_ATTR(interface, S_IRUGO, show_interface_string, NULL);
730 
731 static ssize_t show_modalias(struct device *dev,
732 		struct device_attribute *attr, char *buf)
733 {
734 	struct usb_interface *intf;
735 	struct usb_device *udev;
736 	struct usb_host_interface *alt;
737 
738 	intf = to_usb_interface(dev);
739 	udev = interface_to_usbdev(intf);
740 	alt = intf->cur_altsetting;
741 
742 	return sprintf(buf, "usb:v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02X"
743 			"ic%02Xisc%02Xip%02X\n",
744 			le16_to_cpu(udev->descriptor.idVendor),
745 			le16_to_cpu(udev->descriptor.idProduct),
746 			le16_to_cpu(udev->descriptor.bcdDevice),
747 			udev->descriptor.bDeviceClass,
748 			udev->descriptor.bDeviceSubClass,
749 			udev->descriptor.bDeviceProtocol,
750 			alt->desc.bInterfaceClass,
751 			alt->desc.bInterfaceSubClass,
752 			alt->desc.bInterfaceProtocol);
753 }
754 static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL);
755 
756 static ssize_t show_supports_autosuspend(struct device *dev,
757 		struct device_attribute *attr, char *buf)
758 {
759 	struct usb_interface *intf;
760 	struct usb_device *udev;
761 	int ret;
762 
763 	intf = to_usb_interface(dev);
764 	udev = interface_to_usbdev(intf);
765 
766 	usb_lock_device(udev);
767 	/* Devices will be autosuspended even when an interface isn't claimed */
768 	if (!intf->dev.driver ||
769 			to_usb_driver(intf->dev.driver)->supports_autosuspend)
770 		ret = sprintf(buf, "%u\n", 1);
771 	else
772 		ret = sprintf(buf, "%u\n", 0);
773 	usb_unlock_device(udev);
774 
775 	return ret;
776 }
777 static DEVICE_ATTR(supports_autosuspend, S_IRUGO, show_supports_autosuspend, NULL);
778 
779 static struct attribute *intf_attrs[] = {
780 	&dev_attr_bInterfaceNumber.attr,
781 	&dev_attr_bAlternateSetting.attr,
782 	&dev_attr_bNumEndpoints.attr,
783 	&dev_attr_bInterfaceClass.attr,
784 	&dev_attr_bInterfaceSubClass.attr,
785 	&dev_attr_bInterfaceProtocol.attr,
786 	&dev_attr_modalias.attr,
787 	&dev_attr_supports_autosuspend.attr,
788 	NULL,
789 };
790 static struct attribute_group intf_attr_grp = {
791 	.attrs = intf_attrs,
792 };
793 
794 static struct attribute *intf_assoc_attrs[] = {
795 	&dev_attr_iad_bFirstInterface.attr,
796 	&dev_attr_iad_bInterfaceCount.attr,
797 	&dev_attr_iad_bFunctionClass.attr,
798 	&dev_attr_iad_bFunctionSubClass.attr,
799 	&dev_attr_iad_bFunctionProtocol.attr,
800 	NULL,
801 };
802 
803 static mode_t intf_assoc_attrs_are_visible(struct kobject *kobj,
804 		struct attribute *a, int n)
805 {
806 	struct device *dev = container_of(kobj, struct device, kobj);
807 	struct usb_interface *intf = to_usb_interface(dev);
808 
809 	if (intf->intf_assoc == NULL)
810 		return 0;
811 	return a->mode;
812 }
813 
814 static struct attribute_group intf_assoc_attr_grp = {
815 	.attrs =	intf_assoc_attrs,
816 	.is_visible =	intf_assoc_attrs_are_visible,
817 };
818 
819 const struct attribute_group *usb_interface_groups[] = {
820 	&intf_attr_grp,
821 	&intf_assoc_attr_grp,
822 	NULL
823 };
824 
825 int usb_create_sysfs_intf_files(struct usb_interface *intf)
826 {
827 	struct usb_device *udev = interface_to_usbdev(intf);
828 	struct usb_host_interface *alt = intf->cur_altsetting;
829 	int retval;
830 
831 	if (intf->sysfs_files_created || intf->unregistering)
832 		return 0;
833 
834 	if (alt->string == NULL &&
835 			!(udev->quirks & USB_QUIRK_CONFIG_INTF_STRINGS))
836 		alt->string = usb_cache_string(udev, alt->desc.iInterface);
837 	if (alt->string)
838 		retval = device_create_file(&intf->dev, &dev_attr_interface);
839 	intf->sysfs_files_created = 1;
840 	return 0;
841 }
842 
843 void usb_remove_sysfs_intf_files(struct usb_interface *intf)
844 {
845 	if (!intf->sysfs_files_created)
846 		return;
847 
848 	device_remove_file(&intf->dev, &dev_attr_interface);
849 	intf->sysfs_files_created = 0;
850 }
851