xref: /openbmc/linux/drivers/usb/core/sysfs.c (revision 0ad53fe3)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * drivers/usb/core/sysfs.c
4  *
5  * (C) Copyright 2002 David Brownell
6  * (C) Copyright 2002,2004 Greg Kroah-Hartman
7  * (C) Copyright 2002,2004 IBM Corp.
8  *
9  * All of the sysfs file attributes for usb devices and interfaces.
10  *
11  * Released under the GPLv2 only.
12  */
13 
14 
15 #include <linux/kernel.h>
16 #include <linux/string.h>
17 #include <linux/usb.h>
18 #include <linux/usb/hcd.h>
19 #include <linux/usb/quirks.h>
20 #include <linux/of.h>
21 #include "usb.h"
22 
23 /* Active configuration fields */
24 #define usb_actconfig_show(field, format_string)			\
25 static ssize_t field##_show(struct device *dev,				\
26 			    struct device_attribute *attr, char *buf)	\
27 {									\
28 	struct usb_device *udev;					\
29 	struct usb_host_config *actconfig;				\
30 	ssize_t rc;							\
31 									\
32 	udev = to_usb_device(dev);					\
33 	rc = usb_lock_device_interruptible(udev);			\
34 	if (rc < 0)							\
35 		return -EINTR;						\
36 	actconfig = udev->actconfig;					\
37 	if (actconfig)							\
38 		rc = sprintf(buf, format_string,			\
39 				actconfig->desc.field);			\
40 	usb_unlock_device(udev);					\
41 	return rc;							\
42 }									\
43 
44 #define usb_actconfig_attr(field, format_string)		\
45 	usb_actconfig_show(field, format_string)		\
46 	static DEVICE_ATTR_RO(field)
47 
48 usb_actconfig_attr(bNumInterfaces, "%2d\n");
49 usb_actconfig_attr(bmAttributes, "%2x\n");
50 
51 static ssize_t bMaxPower_show(struct device *dev,
52 		struct device_attribute *attr, char *buf)
53 {
54 	struct usb_device *udev;
55 	struct usb_host_config *actconfig;
56 	ssize_t rc;
57 
58 	udev = to_usb_device(dev);
59 	rc = usb_lock_device_interruptible(udev);
60 	if (rc < 0)
61 		return -EINTR;
62 	actconfig = udev->actconfig;
63 	if (actconfig)
64 		rc = sprintf(buf, "%dmA\n", usb_get_max_power(udev, actconfig));
65 	usb_unlock_device(udev);
66 	return rc;
67 }
68 static DEVICE_ATTR_RO(bMaxPower);
69 
70 static ssize_t configuration_show(struct device *dev,
71 		struct device_attribute *attr, char *buf)
72 {
73 	struct usb_device *udev;
74 	struct usb_host_config *actconfig;
75 	ssize_t rc;
76 
77 	udev = to_usb_device(dev);
78 	rc = usb_lock_device_interruptible(udev);
79 	if (rc < 0)
80 		return -EINTR;
81 	actconfig = udev->actconfig;
82 	if (actconfig && actconfig->string)
83 		rc = sprintf(buf, "%s\n", actconfig->string);
84 	usb_unlock_device(udev);
85 	return rc;
86 }
87 static DEVICE_ATTR_RO(configuration);
88 
89 /* configuration value is always present, and r/w */
90 usb_actconfig_show(bConfigurationValue, "%u\n");
91 
92 static ssize_t bConfigurationValue_store(struct device *dev,
93 					 struct device_attribute *attr,
94 					 const char *buf, size_t count)
95 {
96 	struct usb_device	*udev = to_usb_device(dev);
97 	int			config, value, rc;
98 
99 	if (sscanf(buf, "%d", &config) != 1 || config < -1 || config > 255)
100 		return -EINVAL;
101 	rc = usb_lock_device_interruptible(udev);
102 	if (rc < 0)
103 		return -EINTR;
104 	value = usb_set_configuration(udev, config);
105 	usb_unlock_device(udev);
106 	return (value < 0) ? value : count;
107 }
108 static DEVICE_ATTR_IGNORE_LOCKDEP(bConfigurationValue, S_IRUGO | S_IWUSR,
109 		bConfigurationValue_show, bConfigurationValue_store);
110 
111 #ifdef CONFIG_OF
112 static ssize_t devspec_show(struct device *dev, struct device_attribute *attr,
113 			    char *buf)
114 {
115 	struct device_node *of_node = dev->of_node;
116 
117 	return sprintf(buf, "%pOF\n", of_node);
118 }
119 static DEVICE_ATTR_RO(devspec);
120 #endif
121 
122 /* String fields */
123 #define usb_string_attr(name)						\
124 static ssize_t  name##_show(struct device *dev,				\
125 		struct device_attribute *attr, char *buf)		\
126 {									\
127 	struct usb_device *udev;					\
128 	int retval;							\
129 									\
130 	udev = to_usb_device(dev);					\
131 	retval = usb_lock_device_interruptible(udev);			\
132 	if (retval < 0)							\
133 		return -EINTR;						\
134 	retval = sprintf(buf, "%s\n", udev->name);			\
135 	usb_unlock_device(udev);					\
136 	return retval;							\
137 }									\
138 static DEVICE_ATTR_RO(name)
139 
140 usb_string_attr(product);
141 usb_string_attr(manufacturer);
142 usb_string_attr(serial);
143 
144 static ssize_t speed_show(struct device *dev, struct device_attribute *attr,
145 			  char *buf)
146 {
147 	struct usb_device *udev;
148 	char *speed;
149 
150 	udev = to_usb_device(dev);
151 
152 	switch (udev->speed) {
153 	case USB_SPEED_LOW:
154 		speed = "1.5";
155 		break;
156 	case USB_SPEED_UNKNOWN:
157 	case USB_SPEED_FULL:
158 		speed = "12";
159 		break;
160 	case USB_SPEED_HIGH:
161 		speed = "480";
162 		break;
163 	case USB_SPEED_WIRELESS:
164 		speed = "480";
165 		break;
166 	case USB_SPEED_SUPER:
167 		speed = "5000";
168 		break;
169 	case USB_SPEED_SUPER_PLUS:
170 		if (udev->ssp_rate == USB_SSP_GEN_2x2)
171 			speed = "20000";
172 		else
173 			speed = "10000";
174 		break;
175 	default:
176 		speed = "unknown";
177 	}
178 	return sprintf(buf, "%s\n", speed);
179 }
180 static DEVICE_ATTR_RO(speed);
181 
182 static ssize_t rx_lanes_show(struct device *dev, struct device_attribute *attr,
183 			  char *buf)
184 {
185 	struct usb_device *udev;
186 
187 	udev = to_usb_device(dev);
188 	return sprintf(buf, "%d\n", udev->rx_lanes);
189 }
190 static DEVICE_ATTR_RO(rx_lanes);
191 
192 static ssize_t tx_lanes_show(struct device *dev, struct device_attribute *attr,
193 			  char *buf)
194 {
195 	struct usb_device *udev;
196 
197 	udev = to_usb_device(dev);
198 	return sprintf(buf, "%d\n", udev->tx_lanes);
199 }
200 static DEVICE_ATTR_RO(tx_lanes);
201 
202 static ssize_t busnum_show(struct device *dev, struct device_attribute *attr,
203 			   char *buf)
204 {
205 	struct usb_device *udev;
206 
207 	udev = to_usb_device(dev);
208 	return sprintf(buf, "%d\n", udev->bus->busnum);
209 }
210 static DEVICE_ATTR_RO(busnum);
211 
212 static ssize_t devnum_show(struct device *dev, struct device_attribute *attr,
213 			   char *buf)
214 {
215 	struct usb_device *udev;
216 
217 	udev = to_usb_device(dev);
218 	return sprintf(buf, "%d\n", udev->devnum);
219 }
220 static DEVICE_ATTR_RO(devnum);
221 
222 static ssize_t devpath_show(struct device *dev, struct device_attribute *attr,
223 			    char *buf)
224 {
225 	struct usb_device *udev;
226 
227 	udev = to_usb_device(dev);
228 	return sprintf(buf, "%s\n", udev->devpath);
229 }
230 static DEVICE_ATTR_RO(devpath);
231 
232 static ssize_t version_show(struct device *dev, struct device_attribute *attr,
233 			    char *buf)
234 {
235 	struct usb_device *udev;
236 	u16 bcdUSB;
237 
238 	udev = to_usb_device(dev);
239 	bcdUSB = le16_to_cpu(udev->descriptor.bcdUSB);
240 	return sprintf(buf, "%2x.%02x\n", bcdUSB >> 8, bcdUSB & 0xff);
241 }
242 static DEVICE_ATTR_RO(version);
243 
244 static ssize_t maxchild_show(struct device *dev, struct device_attribute *attr,
245 			     char *buf)
246 {
247 	struct usb_device *udev;
248 
249 	udev = to_usb_device(dev);
250 	return sprintf(buf, "%d\n", udev->maxchild);
251 }
252 static DEVICE_ATTR_RO(maxchild);
253 
254 static ssize_t quirks_show(struct device *dev, struct device_attribute *attr,
255 			   char *buf)
256 {
257 	struct usb_device *udev;
258 
259 	udev = to_usb_device(dev);
260 	return sprintf(buf, "0x%x\n", udev->quirks);
261 }
262 static DEVICE_ATTR_RO(quirks);
263 
264 static ssize_t avoid_reset_quirk_show(struct device *dev,
265 				      struct device_attribute *attr, char *buf)
266 {
267 	struct usb_device *udev;
268 
269 	udev = to_usb_device(dev);
270 	return sprintf(buf, "%d\n", !!(udev->quirks & USB_QUIRK_RESET));
271 }
272 
273 static ssize_t avoid_reset_quirk_store(struct device *dev,
274 				      struct device_attribute *attr,
275 				      const char *buf, size_t count)
276 {
277 	struct usb_device	*udev = to_usb_device(dev);
278 	int			val, rc;
279 
280 	if (sscanf(buf, "%d", &val) != 1 || val < 0 || val > 1)
281 		return -EINVAL;
282 	rc = usb_lock_device_interruptible(udev);
283 	if (rc < 0)
284 		return -EINTR;
285 	if (val)
286 		udev->quirks |= USB_QUIRK_RESET;
287 	else
288 		udev->quirks &= ~USB_QUIRK_RESET;
289 	usb_unlock_device(udev);
290 	return count;
291 }
292 static DEVICE_ATTR_RW(avoid_reset_quirk);
293 
294 static ssize_t urbnum_show(struct device *dev, struct device_attribute *attr,
295 			   char *buf)
296 {
297 	struct usb_device *udev;
298 
299 	udev = to_usb_device(dev);
300 	return sprintf(buf, "%d\n", atomic_read(&udev->urbnum));
301 }
302 static DEVICE_ATTR_RO(urbnum);
303 
304 static ssize_t ltm_capable_show(struct device *dev,
305 				struct device_attribute *attr, char *buf)
306 {
307 	if (usb_device_supports_ltm(to_usb_device(dev)))
308 		return sprintf(buf, "%s\n", "yes");
309 	return sprintf(buf, "%s\n", "no");
310 }
311 static DEVICE_ATTR_RO(ltm_capable);
312 
313 #ifdef	CONFIG_PM
314 
315 static ssize_t persist_show(struct device *dev, struct device_attribute *attr,
316 			    char *buf)
317 {
318 	struct usb_device *udev = to_usb_device(dev);
319 
320 	return sprintf(buf, "%d\n", udev->persist_enabled);
321 }
322 
323 static ssize_t persist_store(struct device *dev, struct device_attribute *attr,
324 			     const char *buf, size_t count)
325 {
326 	struct usb_device *udev = to_usb_device(dev);
327 	int value, rc;
328 
329 	/* Hubs are always enabled for USB_PERSIST */
330 	if (udev->descriptor.bDeviceClass == USB_CLASS_HUB)
331 		return -EPERM;
332 
333 	if (sscanf(buf, "%d", &value) != 1)
334 		return -EINVAL;
335 
336 	rc = usb_lock_device_interruptible(udev);
337 	if (rc < 0)
338 		return -EINTR;
339 	udev->persist_enabled = !!value;
340 	usb_unlock_device(udev);
341 	return count;
342 }
343 static DEVICE_ATTR_RW(persist);
344 
345 static int add_persist_attributes(struct device *dev)
346 {
347 	int rc = 0;
348 
349 	if (is_usb_device(dev)) {
350 		struct usb_device *udev = to_usb_device(dev);
351 
352 		/* Hubs are automatically enabled for USB_PERSIST,
353 		 * no point in creating the attribute file.
354 		 */
355 		if (udev->descriptor.bDeviceClass != USB_CLASS_HUB)
356 			rc = sysfs_add_file_to_group(&dev->kobj,
357 					&dev_attr_persist.attr,
358 					power_group_name);
359 	}
360 	return rc;
361 }
362 
363 static void remove_persist_attributes(struct device *dev)
364 {
365 	sysfs_remove_file_from_group(&dev->kobj,
366 			&dev_attr_persist.attr,
367 			power_group_name);
368 }
369 
370 static ssize_t connected_duration_show(struct device *dev,
371 				       struct device_attribute *attr, char *buf)
372 {
373 	struct usb_device *udev = to_usb_device(dev);
374 
375 	return sprintf(buf, "%u\n",
376 			jiffies_to_msecs(jiffies - udev->connect_time));
377 }
378 static DEVICE_ATTR_RO(connected_duration);
379 
380 /*
381  * If the device is resumed, the last time the device was suspended has
382  * been pre-subtracted from active_duration.  We add the current time to
383  * get the duration that the device was actually active.
384  *
385  * If the device is suspended, the active_duration is up-to-date.
386  */
387 static ssize_t active_duration_show(struct device *dev,
388 				    struct device_attribute *attr, char *buf)
389 {
390 	struct usb_device *udev = to_usb_device(dev);
391 	int duration;
392 
393 	if (udev->state != USB_STATE_SUSPENDED)
394 		duration = jiffies_to_msecs(jiffies + udev->active_duration);
395 	else
396 		duration = jiffies_to_msecs(udev->active_duration);
397 	return sprintf(buf, "%u\n", duration);
398 }
399 static DEVICE_ATTR_RO(active_duration);
400 
401 static ssize_t autosuspend_show(struct device *dev,
402 				struct device_attribute *attr, char *buf)
403 {
404 	return sprintf(buf, "%d\n", dev->power.autosuspend_delay / 1000);
405 }
406 
407 static ssize_t autosuspend_store(struct device *dev,
408 				 struct device_attribute *attr, const char *buf,
409 				 size_t count)
410 {
411 	int value;
412 
413 	if (sscanf(buf, "%d", &value) != 1 || value >= INT_MAX/1000 ||
414 			value <= -INT_MAX/1000)
415 		return -EINVAL;
416 
417 	pm_runtime_set_autosuspend_delay(dev, value * 1000);
418 	return count;
419 }
420 static DEVICE_ATTR_RW(autosuspend);
421 
422 static const char on_string[] = "on";
423 static const char auto_string[] = "auto";
424 
425 static void warn_level(void)
426 {
427 	static int level_warned;
428 
429 	if (!level_warned) {
430 		level_warned = 1;
431 		printk(KERN_WARNING "WARNING! power/level is deprecated; "
432 				"use power/control instead\n");
433 	}
434 }
435 
436 static ssize_t level_show(struct device *dev, struct device_attribute *attr,
437 			  char *buf)
438 {
439 	struct usb_device *udev = to_usb_device(dev);
440 	const char *p = auto_string;
441 
442 	warn_level();
443 	if (udev->state != USB_STATE_SUSPENDED && !udev->dev.power.runtime_auto)
444 		p = on_string;
445 	return sprintf(buf, "%s\n", p);
446 }
447 
448 static ssize_t level_store(struct device *dev, struct device_attribute *attr,
449 			   const char *buf, size_t count)
450 {
451 	struct usb_device *udev = to_usb_device(dev);
452 	int len = count;
453 	char *cp;
454 	int rc = count;
455 	int rv;
456 
457 	warn_level();
458 	cp = memchr(buf, '\n', count);
459 	if (cp)
460 		len = cp - buf;
461 
462 	rv = usb_lock_device_interruptible(udev);
463 	if (rv < 0)
464 		return -EINTR;
465 
466 	if (len == sizeof on_string - 1 &&
467 			strncmp(buf, on_string, len) == 0)
468 		usb_disable_autosuspend(udev);
469 
470 	else if (len == sizeof auto_string - 1 &&
471 			strncmp(buf, auto_string, len) == 0)
472 		usb_enable_autosuspend(udev);
473 
474 	else
475 		rc = -EINVAL;
476 
477 	usb_unlock_device(udev);
478 	return rc;
479 }
480 static DEVICE_ATTR_RW(level);
481 
482 static ssize_t usb2_hardware_lpm_show(struct device *dev,
483 				      struct device_attribute *attr, char *buf)
484 {
485 	struct usb_device *udev = to_usb_device(dev);
486 	const char *p;
487 
488 	if (udev->usb2_hw_lpm_allowed == 1)
489 		p = "enabled";
490 	else
491 		p = "disabled";
492 
493 	return sprintf(buf, "%s\n", p);
494 }
495 
496 static ssize_t usb2_hardware_lpm_store(struct device *dev,
497 				       struct device_attribute *attr,
498 				       const char *buf, size_t count)
499 {
500 	struct usb_device *udev = to_usb_device(dev);
501 	bool value;
502 	int ret;
503 
504 	ret = usb_lock_device_interruptible(udev);
505 	if (ret < 0)
506 		return -EINTR;
507 
508 	ret = strtobool(buf, &value);
509 
510 	if (!ret) {
511 		udev->usb2_hw_lpm_allowed = value;
512 		if (value)
513 			ret = usb_enable_usb2_hardware_lpm(udev);
514 		else
515 			ret = usb_disable_usb2_hardware_lpm(udev);
516 	}
517 
518 	usb_unlock_device(udev);
519 
520 	if (!ret)
521 		return count;
522 
523 	return ret;
524 }
525 static DEVICE_ATTR_RW(usb2_hardware_lpm);
526 
527 static ssize_t usb2_lpm_l1_timeout_show(struct device *dev,
528 					struct device_attribute *attr,
529 					char *buf)
530 {
531 	struct usb_device *udev = to_usb_device(dev);
532 	return sprintf(buf, "%d\n", udev->l1_params.timeout);
533 }
534 
535 static ssize_t usb2_lpm_l1_timeout_store(struct device *dev,
536 					 struct device_attribute *attr,
537 					 const char *buf, size_t count)
538 {
539 	struct usb_device *udev = to_usb_device(dev);
540 	u16 timeout;
541 
542 	if (kstrtou16(buf, 0, &timeout))
543 		return -EINVAL;
544 
545 	udev->l1_params.timeout = timeout;
546 
547 	return count;
548 }
549 static DEVICE_ATTR_RW(usb2_lpm_l1_timeout);
550 
551 static ssize_t usb2_lpm_besl_show(struct device *dev,
552 				  struct device_attribute *attr, char *buf)
553 {
554 	struct usb_device *udev = to_usb_device(dev);
555 	return sprintf(buf, "%d\n", udev->l1_params.besl);
556 }
557 
558 static ssize_t usb2_lpm_besl_store(struct device *dev,
559 				   struct device_attribute *attr,
560 				   const char *buf, size_t count)
561 {
562 	struct usb_device *udev = to_usb_device(dev);
563 	u8 besl;
564 
565 	if (kstrtou8(buf, 0, &besl) || besl > 15)
566 		return -EINVAL;
567 
568 	udev->l1_params.besl = besl;
569 
570 	return count;
571 }
572 static DEVICE_ATTR_RW(usb2_lpm_besl);
573 
574 static ssize_t usb3_hardware_lpm_u1_show(struct device *dev,
575 				      struct device_attribute *attr, char *buf)
576 {
577 	struct usb_device *udev = to_usb_device(dev);
578 	const char *p;
579 	int rc;
580 
581 	rc = usb_lock_device_interruptible(udev);
582 	if (rc < 0)
583 		return -EINTR;
584 
585 	if (udev->usb3_lpm_u1_enabled)
586 		p = "enabled";
587 	else
588 		p = "disabled";
589 
590 	usb_unlock_device(udev);
591 
592 	return sprintf(buf, "%s\n", p);
593 }
594 static DEVICE_ATTR_RO(usb3_hardware_lpm_u1);
595 
596 static ssize_t usb3_hardware_lpm_u2_show(struct device *dev,
597 				      struct device_attribute *attr, char *buf)
598 {
599 	struct usb_device *udev = to_usb_device(dev);
600 	const char *p;
601 	int rc;
602 
603 	rc = usb_lock_device_interruptible(udev);
604 	if (rc < 0)
605 		return -EINTR;
606 
607 	if (udev->usb3_lpm_u2_enabled)
608 		p = "enabled";
609 	else
610 		p = "disabled";
611 
612 	usb_unlock_device(udev);
613 
614 	return sprintf(buf, "%s\n", p);
615 }
616 static DEVICE_ATTR_RO(usb3_hardware_lpm_u2);
617 
618 static struct attribute *usb2_hardware_lpm_attr[] = {
619 	&dev_attr_usb2_hardware_lpm.attr,
620 	&dev_attr_usb2_lpm_l1_timeout.attr,
621 	&dev_attr_usb2_lpm_besl.attr,
622 	NULL,
623 };
624 static const struct attribute_group usb2_hardware_lpm_attr_group = {
625 	.name	= power_group_name,
626 	.attrs	= usb2_hardware_lpm_attr,
627 };
628 
629 static struct attribute *usb3_hardware_lpm_attr[] = {
630 	&dev_attr_usb3_hardware_lpm_u1.attr,
631 	&dev_attr_usb3_hardware_lpm_u2.attr,
632 	NULL,
633 };
634 static const struct attribute_group usb3_hardware_lpm_attr_group = {
635 	.name	= power_group_name,
636 	.attrs	= usb3_hardware_lpm_attr,
637 };
638 
639 static struct attribute *power_attrs[] = {
640 	&dev_attr_autosuspend.attr,
641 	&dev_attr_level.attr,
642 	&dev_attr_connected_duration.attr,
643 	&dev_attr_active_duration.attr,
644 	NULL,
645 };
646 static const struct attribute_group power_attr_group = {
647 	.name	= power_group_name,
648 	.attrs	= power_attrs,
649 };
650 
651 static int add_power_attributes(struct device *dev)
652 {
653 	int rc = 0;
654 
655 	if (is_usb_device(dev)) {
656 		struct usb_device *udev = to_usb_device(dev);
657 		rc = sysfs_merge_group(&dev->kobj, &power_attr_group);
658 		if (udev->usb2_hw_lpm_capable == 1)
659 			rc = sysfs_merge_group(&dev->kobj,
660 					&usb2_hardware_lpm_attr_group);
661 		if ((udev->speed == USB_SPEED_SUPER ||
662 		     udev->speed == USB_SPEED_SUPER_PLUS) &&
663 				udev->lpm_capable == 1)
664 			rc = sysfs_merge_group(&dev->kobj,
665 					&usb3_hardware_lpm_attr_group);
666 	}
667 
668 	return rc;
669 }
670 
671 static void remove_power_attributes(struct device *dev)
672 {
673 	sysfs_unmerge_group(&dev->kobj, &usb2_hardware_lpm_attr_group);
674 	sysfs_unmerge_group(&dev->kobj, &power_attr_group);
675 }
676 
677 #else
678 
679 #define add_persist_attributes(dev)	0
680 #define remove_persist_attributes(dev)	do {} while (0)
681 
682 #define add_power_attributes(dev)	0
683 #define remove_power_attributes(dev)	do {} while (0)
684 
685 #endif	/* CONFIG_PM */
686 
687 
688 /* Descriptor fields */
689 #define usb_descriptor_attr_le16(field, format_string)			\
690 static ssize_t								\
691 field##_show(struct device *dev, struct device_attribute *attr,	\
692 		char *buf)						\
693 {									\
694 	struct usb_device *udev;					\
695 									\
696 	udev = to_usb_device(dev);					\
697 	return sprintf(buf, format_string, 				\
698 			le16_to_cpu(udev->descriptor.field));		\
699 }									\
700 static DEVICE_ATTR_RO(field)
701 
702 usb_descriptor_attr_le16(idVendor, "%04x\n");
703 usb_descriptor_attr_le16(idProduct, "%04x\n");
704 usb_descriptor_attr_le16(bcdDevice, "%04x\n");
705 
706 #define usb_descriptor_attr(field, format_string)			\
707 static ssize_t								\
708 field##_show(struct device *dev, struct device_attribute *attr,	\
709 		char *buf)						\
710 {									\
711 	struct usb_device *udev;					\
712 									\
713 	udev = to_usb_device(dev);					\
714 	return sprintf(buf, format_string, udev->descriptor.field);	\
715 }									\
716 static DEVICE_ATTR_RO(field)
717 
718 usb_descriptor_attr(bDeviceClass, "%02x\n");
719 usb_descriptor_attr(bDeviceSubClass, "%02x\n");
720 usb_descriptor_attr(bDeviceProtocol, "%02x\n");
721 usb_descriptor_attr(bNumConfigurations, "%d\n");
722 usb_descriptor_attr(bMaxPacketSize0, "%d\n");
723 
724 
725 /* show if the device is authorized (1) or not (0) */
726 static ssize_t authorized_show(struct device *dev,
727 			       struct device_attribute *attr, char *buf)
728 {
729 	struct usb_device *usb_dev = to_usb_device(dev);
730 	return snprintf(buf, PAGE_SIZE, "%u\n", usb_dev->authorized);
731 }
732 
733 /*
734  * Authorize a device to be used in the system
735  *
736  * Writing a 0 deauthorizes the device, writing a 1 authorizes it.
737  */
738 static ssize_t authorized_store(struct device *dev,
739 				struct device_attribute *attr, const char *buf,
740 				size_t size)
741 {
742 	ssize_t result;
743 	struct usb_device *usb_dev = to_usb_device(dev);
744 	unsigned val;
745 	result = sscanf(buf, "%u\n", &val);
746 	if (result != 1)
747 		result = -EINVAL;
748 	else if (val == 0)
749 		result = usb_deauthorize_device(usb_dev);
750 	else
751 		result = usb_authorize_device(usb_dev);
752 	return result < 0 ? result : size;
753 }
754 static DEVICE_ATTR_IGNORE_LOCKDEP(authorized, S_IRUGO | S_IWUSR,
755 				  authorized_show, authorized_store);
756 
757 /* "Safely remove a device" */
758 static ssize_t remove_store(struct device *dev, struct device_attribute *attr,
759 			    const char *buf, size_t count)
760 {
761 	struct usb_device *udev = to_usb_device(dev);
762 	int rc = 0;
763 
764 	usb_lock_device(udev);
765 	if (udev->state != USB_STATE_NOTATTACHED) {
766 
767 		/* To avoid races, first unconfigure and then remove */
768 		usb_set_configuration(udev, -1);
769 		rc = usb_remove_device(udev);
770 	}
771 	if (rc == 0)
772 		rc = count;
773 	usb_unlock_device(udev);
774 	return rc;
775 }
776 static DEVICE_ATTR_IGNORE_LOCKDEP(remove, S_IWUSR, NULL, remove_store);
777 
778 
779 static struct attribute *dev_attrs[] = {
780 	/* current configuration's attributes */
781 	&dev_attr_configuration.attr,
782 	&dev_attr_bNumInterfaces.attr,
783 	&dev_attr_bConfigurationValue.attr,
784 	&dev_attr_bmAttributes.attr,
785 	&dev_attr_bMaxPower.attr,
786 	/* device attributes */
787 	&dev_attr_urbnum.attr,
788 	&dev_attr_idVendor.attr,
789 	&dev_attr_idProduct.attr,
790 	&dev_attr_bcdDevice.attr,
791 	&dev_attr_bDeviceClass.attr,
792 	&dev_attr_bDeviceSubClass.attr,
793 	&dev_attr_bDeviceProtocol.attr,
794 	&dev_attr_bNumConfigurations.attr,
795 	&dev_attr_bMaxPacketSize0.attr,
796 	&dev_attr_speed.attr,
797 	&dev_attr_rx_lanes.attr,
798 	&dev_attr_tx_lanes.attr,
799 	&dev_attr_busnum.attr,
800 	&dev_attr_devnum.attr,
801 	&dev_attr_devpath.attr,
802 	&dev_attr_version.attr,
803 	&dev_attr_maxchild.attr,
804 	&dev_attr_quirks.attr,
805 	&dev_attr_avoid_reset_quirk.attr,
806 	&dev_attr_authorized.attr,
807 	&dev_attr_remove.attr,
808 	&dev_attr_ltm_capable.attr,
809 #ifdef CONFIG_OF
810 	&dev_attr_devspec.attr,
811 #endif
812 	NULL,
813 };
814 static const struct attribute_group dev_attr_grp = {
815 	.attrs = dev_attrs,
816 };
817 
818 /* When modifying this list, be sure to modify dev_string_attrs_are_visible()
819  * accordingly.
820  */
821 static struct attribute *dev_string_attrs[] = {
822 	&dev_attr_manufacturer.attr,
823 	&dev_attr_product.attr,
824 	&dev_attr_serial.attr,
825 	NULL
826 };
827 
828 static umode_t dev_string_attrs_are_visible(struct kobject *kobj,
829 		struct attribute *a, int n)
830 {
831 	struct device *dev = kobj_to_dev(kobj);
832 	struct usb_device *udev = to_usb_device(dev);
833 
834 	if (a == &dev_attr_manufacturer.attr) {
835 		if (udev->manufacturer == NULL)
836 			return 0;
837 	} else if (a == &dev_attr_product.attr) {
838 		if (udev->product == NULL)
839 			return 0;
840 	} else if (a == &dev_attr_serial.attr) {
841 		if (udev->serial == NULL)
842 			return 0;
843 	}
844 	return a->mode;
845 }
846 
847 static const struct attribute_group dev_string_attr_grp = {
848 	.attrs =	dev_string_attrs,
849 	.is_visible =	dev_string_attrs_are_visible,
850 };
851 
852 const struct attribute_group *usb_device_groups[] = {
853 	&dev_attr_grp,
854 	&dev_string_attr_grp,
855 	NULL
856 };
857 
858 /* Binary descriptors */
859 
860 static ssize_t
861 read_descriptors(struct file *filp, struct kobject *kobj,
862 		struct bin_attribute *attr,
863 		char *buf, loff_t off, size_t count)
864 {
865 	struct device *dev = kobj_to_dev(kobj);
866 	struct usb_device *udev = to_usb_device(dev);
867 	size_t nleft = count;
868 	size_t srclen, n;
869 	int cfgno;
870 	void *src;
871 	int retval;
872 
873 	retval = usb_lock_device_interruptible(udev);
874 	if (retval < 0)
875 		return -EINTR;
876 	/* The binary attribute begins with the device descriptor.
877 	 * Following that are the raw descriptor entries for all the
878 	 * configurations (config plus subsidiary descriptors).
879 	 */
880 	for (cfgno = -1; cfgno < udev->descriptor.bNumConfigurations &&
881 			nleft > 0; ++cfgno) {
882 		if (cfgno < 0) {
883 			src = &udev->descriptor;
884 			srclen = sizeof(struct usb_device_descriptor);
885 		} else {
886 			src = udev->rawdescriptors[cfgno];
887 			srclen = __le16_to_cpu(udev->config[cfgno].desc.
888 					wTotalLength);
889 		}
890 		if (off < srclen) {
891 			n = min(nleft, srclen - (size_t) off);
892 			memcpy(buf, src + off, n);
893 			nleft -= n;
894 			buf += n;
895 			off = 0;
896 		} else {
897 			off -= srclen;
898 		}
899 	}
900 	usb_unlock_device(udev);
901 	return count - nleft;
902 }
903 
904 static struct bin_attribute dev_bin_attr_descriptors = {
905 	.attr = {.name = "descriptors", .mode = 0444},
906 	.read = read_descriptors,
907 	.size = 18 + 65535,	/* dev descr + max-size raw descriptor */
908 };
909 
910 /*
911  * Show & store the current value of authorized_default
912  */
913 static ssize_t authorized_default_show(struct device *dev,
914 				       struct device_attribute *attr, char *buf)
915 {
916 	struct usb_device *rh_usb_dev = to_usb_device(dev);
917 	struct usb_bus *usb_bus = rh_usb_dev->bus;
918 	struct usb_hcd *hcd;
919 
920 	hcd = bus_to_hcd(usb_bus);
921 	return snprintf(buf, PAGE_SIZE, "%u\n", hcd->dev_policy);
922 }
923 
924 static ssize_t authorized_default_store(struct device *dev,
925 					struct device_attribute *attr,
926 					const char *buf, size_t size)
927 {
928 	ssize_t result;
929 	unsigned int val;
930 	struct usb_device *rh_usb_dev = to_usb_device(dev);
931 	struct usb_bus *usb_bus = rh_usb_dev->bus;
932 	struct usb_hcd *hcd;
933 
934 	hcd = bus_to_hcd(usb_bus);
935 	result = sscanf(buf, "%u\n", &val);
936 	if (result == 1) {
937 		hcd->dev_policy = val <= USB_DEVICE_AUTHORIZE_INTERNAL ?
938 			val : USB_DEVICE_AUTHORIZE_ALL;
939 		result = size;
940 	} else {
941 		result = -EINVAL;
942 	}
943 	return result;
944 }
945 static DEVICE_ATTR_RW(authorized_default);
946 
947 /*
948  * interface_authorized_default_show - show default authorization status
949  * for USB interfaces
950  *
951  * note: interface_authorized_default is the default value
952  *       for initializing the authorized attribute of interfaces
953  */
954 static ssize_t interface_authorized_default_show(struct device *dev,
955 		struct device_attribute *attr, char *buf)
956 {
957 	struct usb_device *usb_dev = to_usb_device(dev);
958 	struct usb_hcd *hcd = bus_to_hcd(usb_dev->bus);
959 
960 	return sprintf(buf, "%u\n", !!HCD_INTF_AUTHORIZED(hcd));
961 }
962 
963 /*
964  * interface_authorized_default_store - store default authorization status
965  * for USB interfaces
966  *
967  * note: interface_authorized_default is the default value
968  *       for initializing the authorized attribute of interfaces
969  */
970 static ssize_t interface_authorized_default_store(struct device *dev,
971 		struct device_attribute *attr, const char *buf, size_t count)
972 {
973 	struct usb_device *usb_dev = to_usb_device(dev);
974 	struct usb_hcd *hcd = bus_to_hcd(usb_dev->bus);
975 	int rc = count;
976 	bool val;
977 
978 	if (strtobool(buf, &val) != 0)
979 		return -EINVAL;
980 
981 	if (val)
982 		set_bit(HCD_FLAG_INTF_AUTHORIZED, &hcd->flags);
983 	else
984 		clear_bit(HCD_FLAG_INTF_AUTHORIZED, &hcd->flags);
985 
986 	return rc;
987 }
988 static DEVICE_ATTR_RW(interface_authorized_default);
989 
990 /* Group all the USB bus attributes */
991 static struct attribute *usb_bus_attrs[] = {
992 		&dev_attr_authorized_default.attr,
993 		&dev_attr_interface_authorized_default.attr,
994 		NULL,
995 };
996 
997 static const struct attribute_group usb_bus_attr_group = {
998 	.name = NULL,	/* we want them in the same directory */
999 	.attrs = usb_bus_attrs,
1000 };
1001 
1002 
1003 static int add_default_authorized_attributes(struct device *dev)
1004 {
1005 	int rc = 0;
1006 
1007 	if (is_usb_device(dev))
1008 		rc = sysfs_create_group(&dev->kobj, &usb_bus_attr_group);
1009 
1010 	return rc;
1011 }
1012 
1013 static void remove_default_authorized_attributes(struct device *dev)
1014 {
1015 	if (is_usb_device(dev)) {
1016 		sysfs_remove_group(&dev->kobj, &usb_bus_attr_group);
1017 	}
1018 }
1019 
1020 int usb_create_sysfs_dev_files(struct usb_device *udev)
1021 {
1022 	struct device *dev = &udev->dev;
1023 	int retval;
1024 
1025 	retval = device_create_bin_file(dev, &dev_bin_attr_descriptors);
1026 	if (retval)
1027 		goto error;
1028 
1029 	retval = add_persist_attributes(dev);
1030 	if (retval)
1031 		goto error;
1032 
1033 	retval = add_power_attributes(dev);
1034 	if (retval)
1035 		goto error;
1036 
1037 	if (is_root_hub(udev)) {
1038 		retval = add_default_authorized_attributes(dev);
1039 		if (retval)
1040 			goto error;
1041 	}
1042 	return retval;
1043 
1044 error:
1045 	usb_remove_sysfs_dev_files(udev);
1046 	return retval;
1047 }
1048 
1049 void usb_remove_sysfs_dev_files(struct usb_device *udev)
1050 {
1051 	struct device *dev = &udev->dev;
1052 
1053 	if (is_root_hub(udev))
1054 		remove_default_authorized_attributes(dev);
1055 
1056 	remove_power_attributes(dev);
1057 	remove_persist_attributes(dev);
1058 	device_remove_bin_file(dev, &dev_bin_attr_descriptors);
1059 }
1060 
1061 /* Interface Association Descriptor fields */
1062 #define usb_intf_assoc_attr(field, format_string)			\
1063 static ssize_t								\
1064 iad_##field##_show(struct device *dev, struct device_attribute *attr,	\
1065 		char *buf)						\
1066 {									\
1067 	struct usb_interface *intf = to_usb_interface(dev);		\
1068 									\
1069 	return sprintf(buf, format_string,				\
1070 			intf->intf_assoc->field); 			\
1071 }									\
1072 static DEVICE_ATTR_RO(iad_##field)
1073 
1074 usb_intf_assoc_attr(bFirstInterface, "%02x\n");
1075 usb_intf_assoc_attr(bInterfaceCount, "%02d\n");
1076 usb_intf_assoc_attr(bFunctionClass, "%02x\n");
1077 usb_intf_assoc_attr(bFunctionSubClass, "%02x\n");
1078 usb_intf_assoc_attr(bFunctionProtocol, "%02x\n");
1079 
1080 /* Interface fields */
1081 #define usb_intf_attr(field, format_string)				\
1082 static ssize_t								\
1083 field##_show(struct device *dev, struct device_attribute *attr,		\
1084 		char *buf)						\
1085 {									\
1086 	struct usb_interface *intf = to_usb_interface(dev);		\
1087 									\
1088 	return sprintf(buf, format_string,				\
1089 			intf->cur_altsetting->desc.field); 		\
1090 }									\
1091 static DEVICE_ATTR_RO(field)
1092 
1093 usb_intf_attr(bInterfaceNumber, "%02x\n");
1094 usb_intf_attr(bAlternateSetting, "%2d\n");
1095 usb_intf_attr(bNumEndpoints, "%02x\n");
1096 usb_intf_attr(bInterfaceClass, "%02x\n");
1097 usb_intf_attr(bInterfaceSubClass, "%02x\n");
1098 usb_intf_attr(bInterfaceProtocol, "%02x\n");
1099 
1100 static ssize_t interface_show(struct device *dev, struct device_attribute *attr,
1101 			      char *buf)
1102 {
1103 	struct usb_interface *intf;
1104 	char *string;
1105 
1106 	intf = to_usb_interface(dev);
1107 	string = READ_ONCE(intf->cur_altsetting->string);
1108 	if (!string)
1109 		return 0;
1110 	return sprintf(buf, "%s\n", string);
1111 }
1112 static DEVICE_ATTR_RO(interface);
1113 
1114 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
1115 			     char *buf)
1116 {
1117 	struct usb_interface *intf;
1118 	struct usb_device *udev;
1119 	struct usb_host_interface *alt;
1120 
1121 	intf = to_usb_interface(dev);
1122 	udev = interface_to_usbdev(intf);
1123 	alt = READ_ONCE(intf->cur_altsetting);
1124 
1125 	return sprintf(buf, "usb:v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02X"
1126 			"ic%02Xisc%02Xip%02Xin%02X\n",
1127 			le16_to_cpu(udev->descriptor.idVendor),
1128 			le16_to_cpu(udev->descriptor.idProduct),
1129 			le16_to_cpu(udev->descriptor.bcdDevice),
1130 			udev->descriptor.bDeviceClass,
1131 			udev->descriptor.bDeviceSubClass,
1132 			udev->descriptor.bDeviceProtocol,
1133 			alt->desc.bInterfaceClass,
1134 			alt->desc.bInterfaceSubClass,
1135 			alt->desc.bInterfaceProtocol,
1136 			alt->desc.bInterfaceNumber);
1137 }
1138 static DEVICE_ATTR_RO(modalias);
1139 
1140 static ssize_t supports_autosuspend_show(struct device *dev,
1141 					 struct device_attribute *attr,
1142 					 char *buf)
1143 {
1144 	int s;
1145 
1146 	s = device_lock_interruptible(dev);
1147 	if (s < 0)
1148 		return -EINTR;
1149 	/* Devices will be autosuspended even when an interface isn't claimed */
1150 	s = (!dev->driver || to_usb_driver(dev->driver)->supports_autosuspend);
1151 	device_unlock(dev);
1152 
1153 	return sprintf(buf, "%u\n", s);
1154 }
1155 static DEVICE_ATTR_RO(supports_autosuspend);
1156 
1157 /*
1158  * interface_authorized_show - show authorization status of an USB interface
1159  * 1 is authorized, 0 is deauthorized
1160  */
1161 static ssize_t interface_authorized_show(struct device *dev,
1162 		struct device_attribute *attr, char *buf)
1163 {
1164 	struct usb_interface *intf = to_usb_interface(dev);
1165 
1166 	return sprintf(buf, "%u\n", intf->authorized);
1167 }
1168 
1169 /*
1170  * interface_authorized_store - authorize or deauthorize an USB interface
1171  */
1172 static ssize_t interface_authorized_store(struct device *dev,
1173 		struct device_attribute *attr, const char *buf, size_t count)
1174 {
1175 	struct usb_interface *intf = to_usb_interface(dev);
1176 	bool val;
1177 
1178 	if (strtobool(buf, &val) != 0)
1179 		return -EINVAL;
1180 
1181 	if (val)
1182 		usb_authorize_interface(intf);
1183 	else
1184 		usb_deauthorize_interface(intf);
1185 
1186 	return count;
1187 }
1188 static struct device_attribute dev_attr_interface_authorized =
1189 		__ATTR(authorized, S_IRUGO | S_IWUSR,
1190 		interface_authorized_show, interface_authorized_store);
1191 
1192 static struct attribute *intf_attrs[] = {
1193 	&dev_attr_bInterfaceNumber.attr,
1194 	&dev_attr_bAlternateSetting.attr,
1195 	&dev_attr_bNumEndpoints.attr,
1196 	&dev_attr_bInterfaceClass.attr,
1197 	&dev_attr_bInterfaceSubClass.attr,
1198 	&dev_attr_bInterfaceProtocol.attr,
1199 	&dev_attr_modalias.attr,
1200 	&dev_attr_supports_autosuspend.attr,
1201 	&dev_attr_interface_authorized.attr,
1202 	NULL,
1203 };
1204 static const struct attribute_group intf_attr_grp = {
1205 	.attrs = intf_attrs,
1206 };
1207 
1208 static struct attribute *intf_assoc_attrs[] = {
1209 	&dev_attr_iad_bFirstInterface.attr,
1210 	&dev_attr_iad_bInterfaceCount.attr,
1211 	&dev_attr_iad_bFunctionClass.attr,
1212 	&dev_attr_iad_bFunctionSubClass.attr,
1213 	&dev_attr_iad_bFunctionProtocol.attr,
1214 	NULL,
1215 };
1216 
1217 static umode_t intf_assoc_attrs_are_visible(struct kobject *kobj,
1218 		struct attribute *a, int n)
1219 {
1220 	struct device *dev = kobj_to_dev(kobj);
1221 	struct usb_interface *intf = to_usb_interface(dev);
1222 
1223 	if (intf->intf_assoc == NULL)
1224 		return 0;
1225 	return a->mode;
1226 }
1227 
1228 static const struct attribute_group intf_assoc_attr_grp = {
1229 	.attrs =	intf_assoc_attrs,
1230 	.is_visible =	intf_assoc_attrs_are_visible,
1231 };
1232 
1233 const struct attribute_group *usb_interface_groups[] = {
1234 	&intf_attr_grp,
1235 	&intf_assoc_attr_grp,
1236 	NULL
1237 };
1238 
1239 void usb_create_sysfs_intf_files(struct usb_interface *intf)
1240 {
1241 	struct usb_device *udev = interface_to_usbdev(intf);
1242 	struct usb_host_interface *alt = intf->cur_altsetting;
1243 
1244 	if (intf->sysfs_files_created || intf->unregistering)
1245 		return;
1246 
1247 	if (!alt->string && !(udev->quirks & USB_QUIRK_CONFIG_INTF_STRINGS))
1248 		alt->string = usb_cache_string(udev, alt->desc.iInterface);
1249 	if (alt->string && device_create_file(&intf->dev, &dev_attr_interface)) {
1250 		/* This is not a serious error */
1251 		dev_dbg(&intf->dev, "interface string descriptor file not created\n");
1252 	}
1253 	intf->sysfs_files_created = 1;
1254 }
1255 
1256 void usb_remove_sysfs_intf_files(struct usb_interface *intf)
1257 {
1258 	if (!intf->sysfs_files_created)
1259 		return;
1260 
1261 	device_remove_file(&intf->dev, &dev_attr_interface);
1262 	intf->sysfs_files_created = 0;
1263 }
1264