xref: /openbmc/linux/drivers/usb/core/sysfs.c (revision 732a675a)
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 "usb.h"
17 
18 /* Active configuration fields */
19 #define usb_actconfig_show(field, multiplier, format_string)		\
20 static ssize_t  show_##field(struct device *dev,			\
21 		struct device_attribute *attr, char *buf)		\
22 {									\
23 	struct usb_device *udev;					\
24 	struct usb_host_config *actconfig;				\
25 									\
26 	udev = to_usb_device(dev);					\
27 	actconfig = udev->actconfig;					\
28 	if (actconfig)							\
29 		return sprintf(buf, format_string,			\
30 				actconfig->desc.field * multiplier);	\
31 	else								\
32 		return 0;						\
33 }									\
34 
35 #define usb_actconfig_attr(field, multiplier, format_string)		\
36 usb_actconfig_show(field, multiplier, format_string)			\
37 static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);
38 
39 usb_actconfig_attr(bNumInterfaces, 1, "%2d\n")
40 usb_actconfig_attr(bmAttributes, 1, "%2x\n")
41 usb_actconfig_attr(bMaxPower, 2, "%3dmA\n")
42 
43 static ssize_t show_configuration_string(struct device *dev,
44 		struct device_attribute *attr, char *buf)
45 {
46 	struct usb_device *udev;
47 	struct usb_host_config *actconfig;
48 
49 	udev = to_usb_device(dev);
50 	actconfig = udev->actconfig;
51 	if ((!actconfig) || (!actconfig->string))
52 		return 0;
53 	return sprintf(buf, "%s\n", actconfig->string);
54 }
55 static DEVICE_ATTR(configuration, S_IRUGO, show_configuration_string, NULL);
56 
57 /* configuration value is always present, and r/w */
58 usb_actconfig_show(bConfigurationValue, 1, "%u\n");
59 
60 static ssize_t
61 set_bConfigurationValue(struct device *dev, struct device_attribute *attr,
62 		const char *buf, size_t count)
63 {
64 	struct usb_device	*udev = to_usb_device(dev);
65 	int			config, value;
66 
67 	if (sscanf(buf, "%d", &config) != 1 || config < -1 || config > 255)
68 		return -EINVAL;
69 	usb_lock_device(udev);
70 	value = usb_set_configuration(udev, config);
71 	usb_unlock_device(udev);
72 	return (value < 0) ? value : count;
73 }
74 
75 static DEVICE_ATTR(bConfigurationValue, S_IRUGO | S_IWUSR,
76 		show_bConfigurationValue, set_bConfigurationValue);
77 
78 /* String fields */
79 #define usb_string_attr(name)						\
80 static ssize_t  show_##name(struct device *dev,				\
81 		struct device_attribute *attr, char *buf)		\
82 {									\
83 	struct usb_device *udev;					\
84 									\
85 	udev = to_usb_device(dev);					\
86 	return sprintf(buf, "%s\n", udev->name);			\
87 }									\
88 static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL);
89 
90 usb_string_attr(product);
91 usb_string_attr(manufacturer);
92 usb_string_attr(serial);
93 
94 static ssize_t
95 show_speed(struct device *dev, struct device_attribute *attr, char *buf)
96 {
97 	struct usb_device *udev;
98 	char *speed;
99 
100 	udev = to_usb_device(dev);
101 
102 	switch (udev->speed) {
103 	case USB_SPEED_LOW:
104 		speed = "1.5";
105 		break;
106 	case USB_SPEED_UNKNOWN:
107 	case USB_SPEED_FULL:
108 		speed = "12";
109 		break;
110 	case USB_SPEED_HIGH:
111 		speed = "480";
112 		break;
113 	default:
114 		speed = "unknown";
115 	}
116 	return sprintf(buf, "%s\n", speed);
117 }
118 static DEVICE_ATTR(speed, S_IRUGO, show_speed, NULL);
119 
120 static ssize_t
121 show_busnum(struct device *dev, struct device_attribute *attr, char *buf)
122 {
123 	struct usb_device *udev;
124 
125 	udev = to_usb_device(dev);
126 	return sprintf(buf, "%d\n", udev->bus->busnum);
127 }
128 static DEVICE_ATTR(busnum, S_IRUGO, show_busnum, NULL);
129 
130 static ssize_t
131 show_devnum(struct device *dev, struct device_attribute *attr, char *buf)
132 {
133 	struct usb_device *udev;
134 
135 	udev = to_usb_device(dev);
136 	return sprintf(buf, "%d\n", udev->devnum);
137 }
138 static DEVICE_ATTR(devnum, S_IRUGO, show_devnum, NULL);
139 
140 static ssize_t
141 show_version(struct device *dev, struct device_attribute *attr, char *buf)
142 {
143 	struct usb_device *udev;
144 	u16 bcdUSB;
145 
146 	udev = to_usb_device(dev);
147 	bcdUSB = le16_to_cpu(udev->descriptor.bcdUSB);
148 	return sprintf(buf, "%2x.%02x\n", bcdUSB >> 8, bcdUSB & 0xff);
149 }
150 static DEVICE_ATTR(version, S_IRUGO, show_version, NULL);
151 
152 static ssize_t
153 show_maxchild(struct device *dev, struct device_attribute *attr, char *buf)
154 {
155 	struct usb_device *udev;
156 
157 	udev = to_usb_device(dev);
158 	return sprintf(buf, "%d\n", udev->maxchild);
159 }
160 static DEVICE_ATTR(maxchild, S_IRUGO, show_maxchild, NULL);
161 
162 static ssize_t
163 show_quirks(struct device *dev, struct device_attribute *attr, char *buf)
164 {
165 	struct usb_device *udev;
166 
167 	udev = to_usb_device(dev);
168 	return sprintf(buf, "0x%x\n", udev->quirks);
169 }
170 static DEVICE_ATTR(quirks, S_IRUGO, show_quirks, NULL);
171 
172 static ssize_t
173 show_urbnum(struct device *dev, struct device_attribute *attr, char *buf)
174 {
175 	struct usb_device *udev;
176 
177 	udev = to_usb_device(dev);
178 	return sprintf(buf, "%d\n", atomic_read(&udev->urbnum));
179 }
180 static DEVICE_ATTR(urbnum, S_IRUGO, show_urbnum, NULL);
181 
182 
183 #ifdef	CONFIG_PM
184 
185 static const char power_group[] = "power";
186 
187 static ssize_t
188 show_persist(struct device *dev, struct device_attribute *attr, char *buf)
189 {
190 	struct usb_device *udev = to_usb_device(dev);
191 
192 	return sprintf(buf, "%d\n", udev->persist_enabled);
193 }
194 
195 static ssize_t
196 set_persist(struct device *dev, struct device_attribute *attr,
197 		const char *buf, size_t count)
198 {
199 	struct usb_device *udev = to_usb_device(dev);
200 	int value;
201 
202 	/* Hubs are always enabled for USB_PERSIST */
203 	if (udev->descriptor.bDeviceClass == USB_CLASS_HUB)
204 		return -EPERM;
205 
206 	if (sscanf(buf, "%d", &value) != 1)
207 		return -EINVAL;
208 	usb_pm_lock(udev);
209 	udev->persist_enabled = !!value;
210 	usb_pm_unlock(udev);
211 	return count;
212 }
213 
214 static DEVICE_ATTR(persist, S_IRUGO | S_IWUSR, show_persist, set_persist);
215 
216 static int add_persist_attributes(struct device *dev)
217 {
218 	int rc = 0;
219 
220 	if (is_usb_device(dev)) {
221 		struct usb_device *udev = to_usb_device(dev);
222 
223 		/* Hubs are automatically enabled for USB_PERSIST,
224 		 * no point in creating the attribute file.
225 		 */
226 		if (udev->descriptor.bDeviceClass != USB_CLASS_HUB)
227 			rc = sysfs_add_file_to_group(&dev->kobj,
228 					&dev_attr_persist.attr,
229 					power_group);
230 	}
231 	return rc;
232 }
233 
234 static void remove_persist_attributes(struct device *dev)
235 {
236 	sysfs_remove_file_from_group(&dev->kobj,
237 			&dev_attr_persist.attr,
238 			power_group);
239 }
240 #else
241 
242 #define add_persist_attributes(dev)	0
243 #define remove_persist_attributes(dev)	do {} while (0)
244 
245 #endif	/* CONFIG_PM */
246 
247 #ifdef	CONFIG_USB_SUSPEND
248 
249 static ssize_t
250 show_connected_duration(struct device *dev, struct device_attribute *attr,
251 		char *buf)
252 {
253 	struct usb_device *udev = to_usb_device(dev);
254 
255 	return sprintf(buf, "%u\n",
256 			jiffies_to_msecs(jiffies - udev->connect_time));
257 }
258 
259 static DEVICE_ATTR(connected_duration, S_IRUGO, show_connected_duration, NULL);
260 
261 /*
262  * If the device is resumed, the last time the device was suspended has
263  * been pre-subtracted from active_duration.  We add the current time to
264  * get the duration that the device was actually active.
265  *
266  * If the device is suspended, the active_duration is up-to-date.
267  */
268 static ssize_t
269 show_active_duration(struct device *dev, struct device_attribute *attr,
270 		char *buf)
271 {
272 	struct usb_device *udev = to_usb_device(dev);
273 	int duration;
274 
275 	if (udev->state != USB_STATE_SUSPENDED)
276 		duration = jiffies_to_msecs(jiffies + udev->active_duration);
277 	else
278 		duration = jiffies_to_msecs(udev->active_duration);
279 	return sprintf(buf, "%u\n", duration);
280 }
281 
282 static DEVICE_ATTR(active_duration, S_IRUGO, show_active_duration, NULL);
283 
284 static ssize_t
285 show_autosuspend(struct device *dev, struct device_attribute *attr, char *buf)
286 {
287 	struct usb_device *udev = to_usb_device(dev);
288 
289 	return sprintf(buf, "%d\n", udev->autosuspend_delay / HZ);
290 }
291 
292 static ssize_t
293 set_autosuspend(struct device *dev, struct device_attribute *attr,
294 		const char *buf, size_t count)
295 {
296 	struct usb_device *udev = to_usb_device(dev);
297 	int value;
298 
299 	if (sscanf(buf, "%d", &value) != 1 || value >= INT_MAX/HZ ||
300 			value <= - INT_MAX/HZ)
301 		return -EINVAL;
302 	value *= HZ;
303 
304 	udev->autosuspend_delay = value;
305 	if (value >= 0)
306 		usb_try_autosuspend_device(udev);
307 	else {
308 		if (usb_autoresume_device(udev) == 0)
309 			usb_autosuspend_device(udev);
310 	}
311 	return count;
312 }
313 
314 static DEVICE_ATTR(autosuspend, S_IRUGO | S_IWUSR,
315 		show_autosuspend, set_autosuspend);
316 
317 static const char on_string[] = "on";
318 static const char auto_string[] = "auto";
319 static const char suspend_string[] = "suspend";
320 
321 static ssize_t
322 show_level(struct device *dev, struct device_attribute *attr, char *buf)
323 {
324 	struct usb_device *udev = to_usb_device(dev);
325 	const char *p = auto_string;
326 
327 	if (udev->state == USB_STATE_SUSPENDED) {
328 		if (udev->autoresume_disabled)
329 			p = suspend_string;
330 	} else {
331 		if (udev->autosuspend_disabled)
332 			p = on_string;
333 	}
334 	return sprintf(buf, "%s\n", p);
335 }
336 
337 static ssize_t
338 set_level(struct device *dev, struct device_attribute *attr,
339 		const char *buf, size_t count)
340 {
341 	struct usb_device *udev = to_usb_device(dev);
342 	int len = count;
343 	char *cp;
344 	int rc = 0;
345 	int old_autosuspend_disabled, old_autoresume_disabled;
346 
347 	cp = memchr(buf, '\n', count);
348 	if (cp)
349 		len = cp - buf;
350 
351 	usb_lock_device(udev);
352 	old_autosuspend_disabled = udev->autosuspend_disabled;
353 	old_autoresume_disabled = udev->autoresume_disabled;
354 
355 	/* Setting the flags without calling usb_pm_lock is a subject to
356 	 * races, but who cares...
357 	 */
358 	if (len == sizeof on_string - 1 &&
359 			strncmp(buf, on_string, len) == 0) {
360 		udev->autosuspend_disabled = 1;
361 		udev->autoresume_disabled = 0;
362 		rc = usb_external_resume_device(udev);
363 
364 	} else if (len == sizeof auto_string - 1 &&
365 			strncmp(buf, auto_string, len) == 0) {
366 		udev->autosuspend_disabled = 0;
367 		udev->autoresume_disabled = 0;
368 		rc = usb_external_resume_device(udev);
369 
370 	} else if (len == sizeof suspend_string - 1 &&
371 			strncmp(buf, suspend_string, len) == 0) {
372 		udev->autosuspend_disabled = 0;
373 		udev->autoresume_disabled = 1;
374 		rc = usb_external_suspend_device(udev, PMSG_SUSPEND);
375 
376 	} else
377 		rc = -EINVAL;
378 
379 	if (rc) {
380 		udev->autosuspend_disabled = old_autosuspend_disabled;
381 		udev->autoresume_disabled = old_autoresume_disabled;
382 	}
383 	usb_unlock_device(udev);
384 	return (rc < 0 ? rc : count);
385 }
386 
387 static DEVICE_ATTR(level, S_IRUGO | S_IWUSR, show_level, set_level);
388 
389 static int add_power_attributes(struct device *dev)
390 {
391 	int rc = 0;
392 
393 	if (is_usb_device(dev)) {
394 		rc = sysfs_add_file_to_group(&dev->kobj,
395 				&dev_attr_autosuspend.attr,
396 				power_group);
397 		if (rc == 0)
398 			rc = sysfs_add_file_to_group(&dev->kobj,
399 					&dev_attr_level.attr,
400 					power_group);
401 		if (rc == 0)
402 			rc = sysfs_add_file_to_group(&dev->kobj,
403 					&dev_attr_connected_duration.attr,
404 					power_group);
405 		if (rc == 0)
406 			rc = sysfs_add_file_to_group(&dev->kobj,
407 					&dev_attr_active_duration.attr,
408 					power_group);
409 	}
410 	return rc;
411 }
412 
413 static void remove_power_attributes(struct device *dev)
414 {
415 	sysfs_remove_file_from_group(&dev->kobj,
416 			&dev_attr_active_duration.attr,
417 			power_group);
418 	sysfs_remove_file_from_group(&dev->kobj,
419 			&dev_attr_connected_duration.attr,
420 			power_group);
421 	sysfs_remove_file_from_group(&dev->kobj,
422 			&dev_attr_level.attr,
423 			power_group);
424 	sysfs_remove_file_from_group(&dev->kobj,
425 			&dev_attr_autosuspend.attr,
426 			power_group);
427 }
428 
429 #else
430 
431 #define add_power_attributes(dev)	0
432 #define remove_power_attributes(dev)	do {} while (0)
433 
434 #endif	/* CONFIG_USB_SUSPEND */
435 
436 
437 /* Descriptor fields */
438 #define usb_descriptor_attr_le16(field, format_string)			\
439 static ssize_t								\
440 show_##field(struct device *dev, struct device_attribute *attr,	\
441 		char *buf)						\
442 {									\
443 	struct usb_device *udev;					\
444 									\
445 	udev = to_usb_device(dev);					\
446 	return sprintf(buf, format_string, 				\
447 			le16_to_cpu(udev->descriptor.field));		\
448 }									\
449 static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);
450 
451 usb_descriptor_attr_le16(idVendor, "%04x\n")
452 usb_descriptor_attr_le16(idProduct, "%04x\n")
453 usb_descriptor_attr_le16(bcdDevice, "%04x\n")
454 
455 #define usb_descriptor_attr(field, format_string)			\
456 static ssize_t								\
457 show_##field(struct device *dev, struct device_attribute *attr,	\
458 		char *buf)						\
459 {									\
460 	struct usb_device *udev;					\
461 									\
462 	udev = to_usb_device(dev);					\
463 	return sprintf(buf, format_string, udev->descriptor.field);	\
464 }									\
465 static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);
466 
467 usb_descriptor_attr(bDeviceClass, "%02x\n")
468 usb_descriptor_attr(bDeviceSubClass, "%02x\n")
469 usb_descriptor_attr(bDeviceProtocol, "%02x\n")
470 usb_descriptor_attr(bNumConfigurations, "%d\n")
471 usb_descriptor_attr(bMaxPacketSize0, "%d\n")
472 
473 
474 
475 /* show if the device is authorized (1) or not (0) */
476 static ssize_t usb_dev_authorized_show(struct device *dev,
477 				       struct device_attribute *attr,
478 				       char *buf)
479 {
480 	struct usb_device *usb_dev = to_usb_device(dev);
481 	return snprintf(buf, PAGE_SIZE, "%u\n", usb_dev->authorized);
482 }
483 
484 
485 /*
486  * Authorize a device to be used in the system
487  *
488  * Writing a 0 deauthorizes the device, writing a 1 authorizes it.
489  */
490 static ssize_t usb_dev_authorized_store(struct device *dev,
491 					struct device_attribute *attr,
492 					const char *buf, size_t size)
493 {
494 	ssize_t result;
495 	struct usb_device *usb_dev = to_usb_device(dev);
496 	unsigned val;
497 	result = sscanf(buf, "%u\n", &val);
498 	if (result != 1)
499 		result = -EINVAL;
500 	else if (val == 0)
501 		result = usb_deauthorize_device(usb_dev);
502 	else
503 		result = usb_authorize_device(usb_dev);
504 	return result < 0? result : size;
505 }
506 
507 static DEVICE_ATTR(authorized, 0644,
508 	    usb_dev_authorized_show, usb_dev_authorized_store);
509 
510 
511 static struct attribute *dev_attrs[] = {
512 	/* current configuration's attributes */
513 	&dev_attr_configuration.attr,
514 	&dev_attr_bNumInterfaces.attr,
515 	&dev_attr_bConfigurationValue.attr,
516 	&dev_attr_bmAttributes.attr,
517 	&dev_attr_bMaxPower.attr,
518 	&dev_attr_urbnum.attr,
519 	/* device attributes */
520 	&dev_attr_idVendor.attr,
521 	&dev_attr_idProduct.attr,
522 	&dev_attr_bcdDevice.attr,
523 	&dev_attr_bDeviceClass.attr,
524 	&dev_attr_bDeviceSubClass.attr,
525 	&dev_attr_bDeviceProtocol.attr,
526 	&dev_attr_bNumConfigurations.attr,
527 	&dev_attr_bMaxPacketSize0.attr,
528 	&dev_attr_speed.attr,
529 	&dev_attr_busnum.attr,
530 	&dev_attr_devnum.attr,
531 	&dev_attr_version.attr,
532 	&dev_attr_maxchild.attr,
533 	&dev_attr_quirks.attr,
534 	&dev_attr_authorized.attr,
535 	NULL,
536 };
537 static struct attribute_group dev_attr_grp = {
538 	.attrs = dev_attrs,
539 };
540 
541 /* When modifying this list, be sure to modify dev_string_attrs_are_visible()
542  * accordingly.
543  */
544 static struct attribute *dev_string_attrs[] = {
545 	&dev_attr_manufacturer.attr,
546 	&dev_attr_product.attr,
547 	&dev_attr_serial.attr,
548 	NULL
549 };
550 
551 static mode_t dev_string_attrs_are_visible(struct kobject *kobj,
552 		struct attribute *a, int n)
553 {
554 	struct usb_device *udev = to_usb_device(
555 			container_of(kobj, struct device, kobj));
556 
557 	if (a == &dev_attr_manufacturer.attr) {
558 		if (udev->manufacturer == NULL)
559 			return 0;
560 	} else if (a == &dev_attr_product.attr) {
561 		if (udev->product == NULL)
562 			return 0;
563 	} else if (a == &dev_attr_serial.attr) {
564 		if (udev->serial == NULL)
565 			return 0;
566 	}
567 	return a->mode;
568 }
569 
570 static struct attribute_group dev_string_attr_grp = {
571 	.attrs =	dev_string_attrs,
572 	.is_visible =	dev_string_attrs_are_visible,
573 };
574 
575 struct attribute_group *usb_device_groups[] = {
576 	&dev_attr_grp,
577 	&dev_string_attr_grp,
578 	NULL
579 };
580 
581 /* Binary descriptors */
582 
583 static ssize_t
584 read_descriptors(struct kobject *kobj, struct bin_attribute *attr,
585 		char *buf, loff_t off, size_t count)
586 {
587 	struct usb_device *udev = to_usb_device(
588 			container_of(kobj, struct device, kobj));
589 	size_t nleft = count;
590 	size_t srclen, n;
591 	int cfgno;
592 	void *src;
593 
594 	/* The binary attribute begins with the device descriptor.
595 	 * Following that are the raw descriptor entries for all the
596 	 * configurations (config plus subsidiary descriptors).
597 	 */
598 	for (cfgno = -1; cfgno < udev->descriptor.bNumConfigurations &&
599 			nleft > 0; ++cfgno) {
600 		if (cfgno < 0) {
601 			src = &udev->descriptor;
602 			srclen = sizeof(struct usb_device_descriptor);
603 		} else {
604 			src = udev->rawdescriptors[cfgno];
605 			srclen = __le16_to_cpu(udev->config[cfgno].desc.
606 					wTotalLength);
607 		}
608 		if (off < srclen) {
609 			n = min(nleft, srclen - (size_t) off);
610 			memcpy(buf, src + off, n);
611 			nleft -= n;
612 			buf += n;
613 			off = 0;
614 		} else {
615 			off -= srclen;
616 		}
617 	}
618 	return count - nleft;
619 }
620 
621 static struct bin_attribute dev_bin_attr_descriptors = {
622 	.attr = {.name = "descriptors", .mode = 0444},
623 	.read = read_descriptors,
624 	.size = 18 + 65535,	/* dev descr + max-size raw descriptor */
625 };
626 
627 int usb_create_sysfs_dev_files(struct usb_device *udev)
628 {
629 	struct device *dev = &udev->dev;
630 	int retval;
631 
632 	/* Unforunately these attributes cannot be created before
633 	 * the uevent is broadcast.
634 	 */
635 	retval = device_create_bin_file(dev, &dev_bin_attr_descriptors);
636 	if (retval)
637 		goto error;
638 
639 	retval = add_persist_attributes(dev);
640 	if (retval)
641 		goto error;
642 
643 	retval = add_power_attributes(dev);
644 	if (retval)
645 		goto error;
646 
647 	retval = usb_create_ep_files(dev, &udev->ep0, udev);
648 	if (retval)
649 		goto error;
650 	return 0;
651 error:
652 	usb_remove_sysfs_dev_files(udev);
653 	return retval;
654 }
655 
656 void usb_remove_sysfs_dev_files(struct usb_device *udev)
657 {
658 	struct device *dev = &udev->dev;
659 
660 	usb_remove_ep_files(&udev->ep0);
661 	remove_power_attributes(dev);
662 	remove_persist_attributes(dev);
663 	device_remove_bin_file(dev, &dev_bin_attr_descriptors);
664 }
665 
666 /* Interface Accociation Descriptor fields */
667 #define usb_intf_assoc_attr(field, format_string)			\
668 static ssize_t								\
669 show_iad_##field(struct device *dev, struct device_attribute *attr,	\
670 		char *buf)						\
671 {									\
672 	struct usb_interface *intf = to_usb_interface(dev);		\
673 									\
674 	return sprintf(buf, format_string,				\
675 			intf->intf_assoc->field); 			\
676 }									\
677 static DEVICE_ATTR(iad_##field, S_IRUGO, show_iad_##field, NULL);
678 
679 usb_intf_assoc_attr(bFirstInterface, "%02x\n")
680 usb_intf_assoc_attr(bInterfaceCount, "%02d\n")
681 usb_intf_assoc_attr(bFunctionClass, "%02x\n")
682 usb_intf_assoc_attr(bFunctionSubClass, "%02x\n")
683 usb_intf_assoc_attr(bFunctionProtocol, "%02x\n")
684 
685 /* Interface fields */
686 #define usb_intf_attr(field, format_string)				\
687 static ssize_t								\
688 show_##field(struct device *dev, struct device_attribute *attr,	\
689 		char *buf)						\
690 {									\
691 	struct usb_interface *intf = to_usb_interface(dev);		\
692 									\
693 	return sprintf(buf, format_string,				\
694 			intf->cur_altsetting->desc.field); 		\
695 }									\
696 static DEVICE_ATTR(field, S_IRUGO, show_##field, NULL);
697 
698 usb_intf_attr(bInterfaceNumber, "%02x\n")
699 usb_intf_attr(bAlternateSetting, "%2d\n")
700 usb_intf_attr(bNumEndpoints, "%02x\n")
701 usb_intf_attr(bInterfaceClass, "%02x\n")
702 usb_intf_attr(bInterfaceSubClass, "%02x\n")
703 usb_intf_attr(bInterfaceProtocol, "%02x\n")
704 
705 static ssize_t show_interface_string(struct device *dev,
706 		struct device_attribute *attr, char *buf)
707 {
708 	struct usb_interface *intf;
709 	char *string;
710 
711 	intf = to_usb_interface(dev);
712 	string = intf->cur_altsetting->string;
713 	barrier();		/* The altsetting might change! */
714 
715 	if (!string)
716 		return 0;
717 	return sprintf(buf, "%s\n", string);
718 }
719 static DEVICE_ATTR(interface, S_IRUGO, show_interface_string, NULL);
720 
721 static ssize_t show_modalias(struct device *dev,
722 		struct device_attribute *attr, char *buf)
723 {
724 	struct usb_interface *intf;
725 	struct usb_device *udev;
726 	struct usb_host_interface *alt;
727 
728 	intf = to_usb_interface(dev);
729 	udev = interface_to_usbdev(intf);
730 	alt = intf->cur_altsetting;
731 
732 	return sprintf(buf, "usb:v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02X"
733 			"ic%02Xisc%02Xip%02X\n",
734 			le16_to_cpu(udev->descriptor.idVendor),
735 			le16_to_cpu(udev->descriptor.idProduct),
736 			le16_to_cpu(udev->descriptor.bcdDevice),
737 			udev->descriptor.bDeviceClass,
738 			udev->descriptor.bDeviceSubClass,
739 			udev->descriptor.bDeviceProtocol,
740 			alt->desc.bInterfaceClass,
741 			alt->desc.bInterfaceSubClass,
742 			alt->desc.bInterfaceProtocol);
743 }
744 static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL);
745 
746 static struct attribute *intf_attrs[] = {
747 	&dev_attr_bInterfaceNumber.attr,
748 	&dev_attr_bAlternateSetting.attr,
749 	&dev_attr_bNumEndpoints.attr,
750 	&dev_attr_bInterfaceClass.attr,
751 	&dev_attr_bInterfaceSubClass.attr,
752 	&dev_attr_bInterfaceProtocol.attr,
753 	&dev_attr_modalias.attr,
754 	NULL,
755 };
756 static struct attribute_group intf_attr_grp = {
757 	.attrs = intf_attrs,
758 };
759 
760 static struct attribute *intf_assoc_attrs[] = {
761 	&dev_attr_iad_bFirstInterface.attr,
762 	&dev_attr_iad_bInterfaceCount.attr,
763 	&dev_attr_iad_bFunctionClass.attr,
764 	&dev_attr_iad_bFunctionSubClass.attr,
765 	&dev_attr_iad_bFunctionProtocol.attr,
766 	NULL,
767 };
768 
769 static mode_t intf_assoc_attrs_are_visible(struct kobject *kobj,
770 		struct attribute *a, int n)
771 {
772 	struct usb_interface *intf = to_usb_interface(
773 			container_of(kobj, struct device, kobj));
774 
775 	if (intf->intf_assoc == NULL)
776 		return 0;
777 	return a->mode;
778 }
779 
780 static struct attribute_group intf_assoc_attr_grp = {
781 	.attrs =	intf_assoc_attrs,
782 	.is_visible =	intf_assoc_attrs_are_visible,
783 };
784 
785 struct attribute_group *usb_interface_groups[] = {
786 	&intf_attr_grp,
787 	&intf_assoc_attr_grp,
788 	NULL
789 };
790 
791 static inline void usb_create_intf_ep_files(struct usb_interface *intf,
792 		struct usb_device *udev)
793 {
794 	struct usb_host_interface *iface_desc;
795 	int i;
796 
797 	iface_desc = intf->cur_altsetting;
798 	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i)
799 		usb_create_ep_files(&intf->dev, &iface_desc->endpoint[i],
800 				udev);
801 }
802 
803 static inline void usb_remove_intf_ep_files(struct usb_interface *intf)
804 {
805 	struct usb_host_interface *iface_desc;
806 	int i;
807 
808 	iface_desc = intf->cur_altsetting;
809 	for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i)
810 		usb_remove_ep_files(&iface_desc->endpoint[i]);
811 }
812 
813 int usb_create_sysfs_intf_files(struct usb_interface *intf)
814 {
815 	struct usb_device *udev = interface_to_usbdev(intf);
816 	struct usb_host_interface *alt = intf->cur_altsetting;
817 	int retval;
818 
819 	if (intf->sysfs_files_created)
820 		return 0;
821 
822 	/* The interface string may be present in some altsettings
823 	 * and missing in others.  Hence its attribute cannot be created
824 	 * before the uevent is broadcast.
825 	 */
826 	if (alt->string == NULL)
827 		alt->string = usb_cache_string(udev, alt->desc.iInterface);
828 	if (alt->string)
829 		retval = device_create_file(&intf->dev, &dev_attr_interface);
830 	usb_create_intf_ep_files(intf, udev);
831 	intf->sysfs_files_created = 1;
832 	return 0;
833 }
834 
835 void usb_remove_sysfs_intf_files(struct usb_interface *intf)
836 {
837 	struct device *dev = &intf->dev;
838 
839 	if (!intf->sysfs_files_created)
840 		return;
841 	usb_remove_intf_ep_files(intf);
842 	device_remove_file(dev, &dev_attr_interface);
843 	intf->sysfs_files_created = 0;
844 }
845