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/kstrtox.h>
17#include <linux/string.h>
18#include <linux/usb.h>
19#include <linux/usb/hcd.h>
20#include <linux/usb/quirks.h>
21#include <linux/of.h>
22#include "usb.h"
23
24/* Active configuration fields */
25#define usb_actconfig_show(field, format_string) \
26static ssize_t field##_show(struct device *dev, \
27 struct device_attribute *attr, char *buf) \
28{ \
29 struct usb_device *udev; \
30 struct usb_host_config *actconfig; \
31 ssize_t rc; \
32 \
33 udev = to_usb_device(dev); \
34 rc = usb_lock_device_interruptible(udev); \
35 if (rc < 0) \
36 return -EINTR; \
37 actconfig = udev->actconfig; \
38 if (actconfig) \
39 rc = sysfs_emit(buf, format_string, \
40 actconfig->desc.field); \
41 usb_unlock_device(udev); \
42 return rc; \
43} \
44
45#define usb_actconfig_attr(field, format_string) \
46 usb_actconfig_show(field, format_string) \
47 static DEVICE_ATTR_RO(field)
48
49usb_actconfig_attr(bNumInterfaces, "%2d\n");
50usb_actconfig_attr(bmAttributes, "%2x\n");
51
52static ssize_t bMaxPower_show(struct device *dev,
53 struct device_attribute *attr, char *buf)
54{
55 struct usb_device *udev;
56 struct usb_host_config *actconfig;
57 ssize_t rc;
58
59 udev = to_usb_device(dev);
60 rc = usb_lock_device_interruptible(udev);
61 if (rc < 0)
62 return -EINTR;
63 actconfig = udev->actconfig;
64 if (actconfig)
65 rc = sysfs_emit(buf, fmt: "%dmA\n", usb_get_max_power(udev, c: actconfig));
66 usb_unlock_device(udev);
67 return rc;
68}
69static DEVICE_ATTR_RO(bMaxPower);
70
71static ssize_t configuration_show(struct device *dev,
72 struct device_attribute *attr, char *buf)
73{
74 struct usb_device *udev;
75 struct usb_host_config *actconfig;
76 ssize_t rc;
77
78 udev = to_usb_device(dev);
79 rc = usb_lock_device_interruptible(udev);
80 if (rc < 0)
81 return -EINTR;
82 actconfig = udev->actconfig;
83 if (actconfig && actconfig->string)
84 rc = sysfs_emit(buf, fmt: "%s\n", actconfig->string);
85 usb_unlock_device(udev);
86 return rc;
87}
88static DEVICE_ATTR_RO(configuration);
89
90/* configuration value is always present, and r/w */
91usb_actconfig_show(bConfigurationValue, "%u\n");
92
93static ssize_t bConfigurationValue_store(struct device *dev,
94 struct device_attribute *attr,
95 const char *buf, size_t count)
96{
97 struct usb_device *udev = to_usb_device(dev);
98 int config, value, rc;
99
100 if (sscanf(buf, "%d", &config) != 1 || config < -1 || config > 255)
101 return -EINVAL;
102 rc = usb_lock_device_interruptible(udev);
103 if (rc < 0)
104 return -EINTR;
105 value = usb_set_configuration(dev: udev, configuration: config);
106 usb_unlock_device(udev);
107 return (value < 0) ? value : count;
108}
109static DEVICE_ATTR_IGNORE_LOCKDEP(bConfigurationValue, S_IRUGO | S_IWUSR,
110 bConfigurationValue_show, bConfigurationValue_store);
111
112#ifdef CONFIG_OF
113static ssize_t devspec_show(struct device *dev, struct device_attribute *attr,
114 char *buf)
115{
116 struct device_node *of_node = dev->of_node;
117
118 return sysfs_emit(buf, fmt: "%pOF\n", of_node);
119}
120static DEVICE_ATTR_RO(devspec);
121#endif
122
123/* String fields */
124#define usb_string_attr(name) \
125static ssize_t name##_show(struct device *dev, \
126 struct device_attribute *attr, char *buf) \
127{ \
128 struct usb_device *udev; \
129 int retval; \
130 \
131 udev = to_usb_device(dev); \
132 retval = usb_lock_device_interruptible(udev); \
133 if (retval < 0) \
134 return -EINTR; \
135 retval = sysfs_emit(buf, "%s\n", udev->name); \
136 usb_unlock_device(udev); \
137 return retval; \
138} \
139static DEVICE_ATTR_RO(name)
140
141usb_string_attr(product);
142usb_string_attr(manufacturer);
143usb_string_attr(serial);
144
145static ssize_t speed_show(struct device *dev, struct device_attribute *attr,
146 char *buf)
147{
148 struct usb_device *udev;
149 char *speed;
150
151 udev = to_usb_device(dev);
152
153 switch (udev->speed) {
154 case USB_SPEED_LOW:
155 speed = "1.5";
156 break;
157 case USB_SPEED_UNKNOWN:
158 case USB_SPEED_FULL:
159 speed = "12";
160 break;
161 case USB_SPEED_HIGH:
162 speed = "480";
163 break;
164 case USB_SPEED_SUPER:
165 speed = "5000";
166 break;
167 case USB_SPEED_SUPER_PLUS:
168 if (udev->ssp_rate == USB_SSP_GEN_2x2)
169 speed = "20000";
170 else
171 speed = "10000";
172 break;
173 default:
174 speed = "unknown";
175 }
176 return sysfs_emit(buf, fmt: "%s\n", speed);
177}
178static DEVICE_ATTR_RO(speed);
179
180static ssize_t rx_lanes_show(struct device *dev, struct device_attribute *attr,
181 char *buf)
182{
183 struct usb_device *udev;
184
185 udev = to_usb_device(dev);
186 return sysfs_emit(buf, fmt: "%d\n", udev->rx_lanes);
187}
188static DEVICE_ATTR_RO(rx_lanes);
189
190static ssize_t tx_lanes_show(struct device *dev, struct device_attribute *attr,
191 char *buf)
192{
193 struct usb_device *udev;
194
195 udev = to_usb_device(dev);
196 return sysfs_emit(buf, fmt: "%d\n", udev->tx_lanes);
197}
198static DEVICE_ATTR_RO(tx_lanes);
199
200static ssize_t busnum_show(struct device *dev, struct device_attribute *attr,
201 char *buf)
202{
203 struct usb_device *udev;
204
205 udev = to_usb_device(dev);
206 return sysfs_emit(buf, fmt: "%d\n", udev->bus->busnum);
207}
208static DEVICE_ATTR_RO(busnum);
209
210static ssize_t devnum_show(struct device *dev, struct device_attribute *attr,
211 char *buf)
212{
213 struct usb_device *udev;
214
215 udev = to_usb_device(dev);
216 return sysfs_emit(buf, fmt: "%d\n", udev->devnum);
217}
218static DEVICE_ATTR_RO(devnum);
219
220static ssize_t devpath_show(struct device *dev, struct device_attribute *attr,
221 char *buf)
222{
223 struct usb_device *udev;
224
225 udev = to_usb_device(dev);
226 return sysfs_emit(buf, fmt: "%s\n", udev->devpath);
227}
228static DEVICE_ATTR_RO(devpath);
229
230static ssize_t version_show(struct device *dev, struct device_attribute *attr,
231 char *buf)
232{
233 struct usb_device *udev;
234 u16 bcdUSB;
235
236 udev = to_usb_device(dev);
237 bcdUSB = le16_to_cpu(udev->descriptor.bcdUSB);
238 return sysfs_emit(buf, fmt: "%2x.%02x\n", bcdUSB >> 8, bcdUSB & 0xff);
239}
240static DEVICE_ATTR_RO(version);
241
242static ssize_t maxchild_show(struct device *dev, struct device_attribute *attr,
243 char *buf)
244{
245 struct usb_device *udev;
246
247 udev = to_usb_device(dev);
248 return sysfs_emit(buf, fmt: "%d\n", udev->maxchild);
249}
250static DEVICE_ATTR_RO(maxchild);
251
252static ssize_t quirks_show(struct device *dev, struct device_attribute *attr,
253 char *buf)
254{
255 struct usb_device *udev;
256
257 udev = to_usb_device(dev);
258 return sysfs_emit(buf, fmt: "0x%x\n", udev->quirks);
259}
260static DEVICE_ATTR_RO(quirks);
261
262static ssize_t avoid_reset_quirk_show(struct device *dev,
263 struct device_attribute *attr, char *buf)
264{
265 struct usb_device *udev;
266
267 udev = to_usb_device(dev);
268 return sysfs_emit(buf, fmt: "%d\n", !!(udev->quirks & USB_QUIRK_RESET));
269}
270
271static ssize_t avoid_reset_quirk_store(struct device *dev,
272 struct device_attribute *attr,
273 const char *buf, size_t count)
274{
275 struct usb_device *udev = to_usb_device(dev);
276 bool val;
277 int rc;
278
279 if (kstrtobool(s: buf, res: &val) != 0)
280 return -EINVAL;
281 rc = usb_lock_device_interruptible(udev);
282 if (rc < 0)
283 return -EINTR;
284 if (val)
285 udev->quirks |= USB_QUIRK_RESET;
286 else
287 udev->quirks &= ~USB_QUIRK_RESET;
288 usb_unlock_device(udev);
289 return count;
290}
291static DEVICE_ATTR_RW(avoid_reset_quirk);
292
293static ssize_t urbnum_show(struct device *dev, struct device_attribute *attr,
294 char *buf)
295{
296 struct usb_device *udev;
297
298 udev = to_usb_device(dev);
299 return sysfs_emit(buf, fmt: "%d\n", atomic_read(v: &udev->urbnum));
300}
301static DEVICE_ATTR_RO(urbnum);
302
303static ssize_t ltm_capable_show(struct device *dev,
304 struct device_attribute *attr, char *buf)
305{
306 if (usb_device_supports_ltm(to_usb_device(dev)))
307 return sysfs_emit(buf, fmt: "%s\n", "yes");
308 return sysfs_emit(buf, fmt: "%s\n", "no");
309}
310static DEVICE_ATTR_RO(ltm_capable);
311
312#ifdef CONFIG_PM
313
314static ssize_t persist_show(struct device *dev, struct device_attribute *attr,
315 char *buf)
316{
317 struct usb_device *udev = to_usb_device(dev);
318
319 return sysfs_emit(buf, fmt: "%d\n", udev->persist_enabled);
320}
321
322static ssize_t persist_store(struct device *dev, struct device_attribute *attr,
323 const char *buf, size_t count)
324{
325 struct usb_device *udev = to_usb_device(dev);
326 bool value;
327 int rc;
328
329 /* Hubs are always enabled for USB_PERSIST */
330 if (udev->descriptor.bDeviceClass == USB_CLASS_HUB)
331 return -EPERM;
332
333 if (kstrtobool(s: buf, res: &value) != 0)
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}
343static DEVICE_ATTR_RW(persist);
344
345static 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(kobj: &dev->kobj,
357 attr: &dev_attr_persist.attr,
358 group: power_group_name);
359 }
360 return rc;
361}
362
363static void remove_persist_attributes(struct device *dev)
364{
365 sysfs_remove_file_from_group(kobj: &dev->kobj,
366 attr: &dev_attr_persist.attr,
367 group: power_group_name);
368}
369
370static 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 sysfs_emit(buf, fmt: "%u\n",
376 jiffies_to_msecs(j: jiffies - udev->connect_time));
377}
378static 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 */
387static 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(j: jiffies + udev->active_duration);
395 else
396 duration = jiffies_to_msecs(j: udev->active_duration);
397 return sysfs_emit(buf, fmt: "%u\n", duration);
398}
399static DEVICE_ATTR_RO(active_duration);
400
401static ssize_t autosuspend_show(struct device *dev,
402 struct device_attribute *attr, char *buf)
403{
404 return sysfs_emit(buf, fmt: "%d\n", dev->power.autosuspend_delay / 1000);
405}
406
407static 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, delay: value * 1000);
418 return count;
419}
420static DEVICE_ATTR_RW(autosuspend);
421
422static const char on_string[] = "on";
423static const char auto_string[] = "auto";
424
425static 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
436static 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 sysfs_emit(buf, fmt: "%s\n", p);
446}
447
448static 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(p: buf, c: '\n', size: 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}
480static DEVICE_ATTR_RW(level);
481
482static 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 sysfs_emit(buf, fmt: "%s\n", p);
494}
495
496static 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 = kstrtobool(s: buf, res: &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}
525static DEVICE_ATTR_RW(usb2_hardware_lpm);
526
527static 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 sysfs_emit(buf, fmt: "%d\n", udev->l1_params.timeout);
533}
534
535static 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(s: buf, base: 0, res: &timeout))
543 return -EINVAL;
544
545 udev->l1_params.timeout = timeout;
546
547 return count;
548}
549static DEVICE_ATTR_RW(usb2_lpm_l1_timeout);
550
551static 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 sysfs_emit(buf, fmt: "%d\n", udev->l1_params.besl);
556}
557
558static 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(s: buf, base: 0, res: &besl) || besl > 15)
566 return -EINVAL;
567
568 udev->l1_params.besl = besl;
569
570 return count;
571}
572static DEVICE_ATTR_RW(usb2_lpm_besl);
573
574static 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 sysfs_emit(buf, fmt: "%s\n", p);
593}
594static DEVICE_ATTR_RO(usb3_hardware_lpm_u1);
595
596static 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 sysfs_emit(buf, fmt: "%s\n", p);
615}
616static DEVICE_ATTR_RO(usb3_hardware_lpm_u2);
617
618static 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};
624static const struct attribute_group usb2_hardware_lpm_attr_group = {
625 .name = power_group_name,
626 .attrs = usb2_hardware_lpm_attr,
627};
628
629static 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};
634static const struct attribute_group usb3_hardware_lpm_attr_group = {
635 .name = power_group_name,
636 .attrs = usb3_hardware_lpm_attr,
637};
638
639static 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};
646static const struct attribute_group power_attr_group = {
647 .name = power_group_name,
648 .attrs = power_attrs,
649};
650
651static 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(kobj: &dev->kobj, grp: &power_attr_group);
658 if (udev->usb2_hw_lpm_capable == 1)
659 rc = sysfs_merge_group(kobj: &dev->kobj,
660 grp: &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(kobj: &dev->kobj,
665 grp: &usb3_hardware_lpm_attr_group);
666 }
667
668 return rc;
669}
670
671static void remove_power_attributes(struct device *dev)
672{
673 sysfs_unmerge_group(kobj: &dev->kobj, grp: &usb2_hardware_lpm_attr_group);
674 sysfs_unmerge_group(kobj: &dev->kobj, grp: &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) \
690static ssize_t \
691field##_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 sysfs_emit(buf, format_string, \
698 le16_to_cpu(udev->descriptor.field)); \
699} \
700static DEVICE_ATTR_RO(field)
701
702usb_descriptor_attr_le16(idVendor, "%04x\n");
703usb_descriptor_attr_le16(idProduct, "%04x\n");
704usb_descriptor_attr_le16(bcdDevice, "%04x\n");
705
706#define usb_descriptor_attr(field, format_string) \
707static ssize_t \
708field##_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 sysfs_emit(buf, format_string, udev->descriptor.field); \
715} \
716static DEVICE_ATTR_RO(field)
717
718usb_descriptor_attr(bDeviceClass, "%02x\n");
719usb_descriptor_attr(bDeviceSubClass, "%02x\n");
720usb_descriptor_attr(bDeviceProtocol, "%02x\n");
721usb_descriptor_attr(bNumConfigurations, "%d\n");
722usb_descriptor_attr(bMaxPacketSize0, "%d\n");
723
724
725/* show if the device is authorized (1) or not (0) */
726static 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 sysfs_emit(buf, fmt: "%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 */
738static 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 bool val;
745
746 if (kstrtobool(s: buf, res: &val) != 0)
747 result = -EINVAL;
748 else if (val)
749 result = usb_authorize_device(usb_dev);
750 else
751 result = usb_deauthorize_device(usb_dev);
752 return result < 0 ? result : size;
753}
754static DEVICE_ATTR_IGNORE_LOCKDEP(authorized, S_IRUGO | S_IWUSR,
755 authorized_show, authorized_store);
756
757/* "Safely remove a device" */
758static 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(dev: udev, configuration: -1);
769 rc = usb_remove_device(udev);
770 }
771 if (rc == 0)
772 rc = count;
773 usb_unlock_device(udev);
774 return rc;
775}
776static DEVICE_ATTR_IGNORE_LOCKDEP(remove, S_IWUSR, NULL, remove_store);
777
778
779static 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};
814static 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 */
821static struct attribute *dev_string_attrs[] = {
822 &dev_attr_manufacturer.attr,
823 &dev_attr_product.attr,
824 &dev_attr_serial.attr,
825 NULL
826};
827
828static 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
847static const struct attribute_group dev_string_attr_grp = {
848 .attrs = dev_string_attrs,
849 .is_visible = dev_string_attrs_are_visible,
850};
851
852/* Binary descriptors */
853
854static ssize_t
855descriptors_read(struct file *filp, struct kobject *kobj,
856 struct bin_attribute *attr,
857 char *buf, loff_t off, size_t count)
858{
859 struct device *dev = kobj_to_dev(kobj);
860 struct usb_device *udev = to_usb_device(dev);
861 size_t nleft = count;
862 size_t srclen, n;
863 int cfgno;
864 void *src;
865
866 /* The binary attribute begins with the device descriptor.
867 * Following that are the raw descriptor entries for all the
868 * configurations (config plus subsidiary descriptors).
869 */
870 for (cfgno = -1; cfgno < udev->descriptor.bNumConfigurations &&
871 nleft > 0; ++cfgno) {
872 if (cfgno < 0) {
873 src = &udev->descriptor;
874 srclen = sizeof(struct usb_device_descriptor);
875 } else {
876 src = udev->rawdescriptors[cfgno];
877 srclen = le16_to_cpu(udev->config[cfgno].desc.
878 wTotalLength);
879 }
880 if (off < srclen) {
881 n = min(nleft, srclen - (size_t) off);
882 memcpy(buf, src + off, n);
883 nleft -= n;
884 buf += n;
885 off = 0;
886 } else {
887 off -= srclen;
888 }
889 }
890 return count - nleft;
891}
892static BIN_ATTR_RO(descriptors, 18 + 65535); /* dev descr + max-size raw descriptor */
893
894static ssize_t
895bos_descriptors_read(struct file *filp, struct kobject *kobj,
896 struct bin_attribute *attr,
897 char *buf, loff_t off, size_t count)
898{
899 struct device *dev = kobj_to_dev(kobj);
900 struct usb_device *udev = to_usb_device(dev);
901 struct usb_host_bos *bos = udev->bos;
902 struct usb_bos_descriptor *desc;
903 size_t desclen, n = 0;
904
905 if (bos) {
906 desc = bos->desc;
907 desclen = le16_to_cpu(desc->wTotalLength);
908 if (off < desclen) {
909 n = min(count, desclen - (size_t) off);
910 memcpy(buf, (void *) desc + off, n);
911 }
912 }
913 return n;
914}
915static BIN_ATTR_RO(bos_descriptors, 65535); /* max-size BOS */
916
917/* When modifying this list, be sure to modify dev_bin_attrs_are_visible()
918 * accordingly.
919 */
920static struct bin_attribute *dev_bin_attrs[] = {
921 &bin_attr_descriptors,
922 &bin_attr_bos_descriptors,
923 NULL
924};
925
926static umode_t dev_bin_attrs_are_visible(struct kobject *kobj,
927 struct bin_attribute *a, int n)
928{
929 struct device *dev = kobj_to_dev(kobj);
930 struct usb_device *udev = to_usb_device(dev);
931
932 /*
933 * There's no need to check if the descriptors attribute should
934 * be visible because all devices have a device descriptor. The
935 * bos_descriptors attribute should be visible if and only if
936 * the device has a BOS, so check if it exists here.
937 */
938 if (a == &bin_attr_bos_descriptors) {
939 if (udev->bos == NULL)
940 return 0;
941 }
942 return a->attr.mode;
943}
944
945static const struct attribute_group dev_bin_attr_grp = {
946 .bin_attrs = dev_bin_attrs,
947 .is_bin_visible = dev_bin_attrs_are_visible,
948};
949
950const struct attribute_group *usb_device_groups[] = {
951 &dev_attr_grp,
952 &dev_string_attr_grp,
953 &dev_bin_attr_grp,
954 NULL
955};
956
957/*
958 * Show & store the current value of authorized_default
959 */
960static ssize_t authorized_default_show(struct device *dev,
961 struct device_attribute *attr, char *buf)
962{
963 struct usb_device *rh_usb_dev = to_usb_device(dev);
964 struct usb_bus *usb_bus = rh_usb_dev->bus;
965 struct usb_hcd *hcd;
966
967 hcd = bus_to_hcd(bus: usb_bus);
968 return sysfs_emit(buf, fmt: "%u\n", hcd->dev_policy);
969}
970
971static ssize_t authorized_default_store(struct device *dev,
972 struct device_attribute *attr,
973 const char *buf, size_t size)
974{
975 ssize_t result;
976 unsigned int val;
977 struct usb_device *rh_usb_dev = to_usb_device(dev);
978 struct usb_bus *usb_bus = rh_usb_dev->bus;
979 struct usb_hcd *hcd;
980
981 hcd = bus_to_hcd(bus: usb_bus);
982 result = sscanf(buf, "%u\n", &val);
983 if (result == 1) {
984 hcd->dev_policy = val <= USB_DEVICE_AUTHORIZE_INTERNAL ?
985 val : USB_DEVICE_AUTHORIZE_ALL;
986 result = size;
987 } else {
988 result = -EINVAL;
989 }
990 return result;
991}
992static DEVICE_ATTR_RW(authorized_default);
993
994/*
995 * interface_authorized_default_show - show default authorization status
996 * for USB interfaces
997 *
998 * note: interface_authorized_default is the default value
999 * for initializing the authorized attribute of interfaces
1000 */
1001static ssize_t interface_authorized_default_show(struct device *dev,
1002 struct device_attribute *attr, char *buf)
1003{
1004 struct usb_device *usb_dev = to_usb_device(dev);
1005 struct usb_hcd *hcd = bus_to_hcd(bus: usb_dev->bus);
1006
1007 return sysfs_emit(buf, fmt: "%u\n", !!HCD_INTF_AUTHORIZED(hcd));
1008}
1009
1010/*
1011 * interface_authorized_default_store - store default authorization status
1012 * for USB interfaces
1013 *
1014 * note: interface_authorized_default is the default value
1015 * for initializing the authorized attribute of interfaces
1016 */
1017static ssize_t interface_authorized_default_store(struct device *dev,
1018 struct device_attribute *attr, const char *buf, size_t count)
1019{
1020 struct usb_device *usb_dev = to_usb_device(dev);
1021 struct usb_hcd *hcd = bus_to_hcd(bus: usb_dev->bus);
1022 int rc = count;
1023 bool val;
1024
1025 if (kstrtobool(s: buf, res: &val) != 0)
1026 return -EINVAL;
1027
1028 if (val)
1029 set_bit(HCD_FLAG_INTF_AUTHORIZED, addr: &hcd->flags);
1030 else
1031 clear_bit(HCD_FLAG_INTF_AUTHORIZED, addr: &hcd->flags);
1032
1033 return rc;
1034}
1035static DEVICE_ATTR_RW(interface_authorized_default);
1036
1037/* Group all the USB bus attributes */
1038static struct attribute *usb_bus_attrs[] = {
1039 &dev_attr_authorized_default.attr,
1040 &dev_attr_interface_authorized_default.attr,
1041 NULL,
1042};
1043
1044static const struct attribute_group usb_bus_attr_group = {
1045 .name = NULL, /* we want them in the same directory */
1046 .attrs = usb_bus_attrs,
1047};
1048
1049
1050static int add_default_authorized_attributes(struct device *dev)
1051{
1052 int rc = 0;
1053
1054 if (is_usb_device(dev))
1055 rc = sysfs_create_group(kobj: &dev->kobj, grp: &usb_bus_attr_group);
1056
1057 return rc;
1058}
1059
1060static void remove_default_authorized_attributes(struct device *dev)
1061{
1062 if (is_usb_device(dev)) {
1063 sysfs_remove_group(kobj: &dev->kobj, grp: &usb_bus_attr_group);
1064 }
1065}
1066
1067int usb_create_sysfs_dev_files(struct usb_device *udev)
1068{
1069 struct device *dev = &udev->dev;
1070 int retval;
1071
1072 retval = add_persist_attributes(dev);
1073 if (retval)
1074 goto error;
1075
1076 retval = add_power_attributes(dev);
1077 if (retval)
1078 goto error;
1079
1080 if (is_root_hub(udev)) {
1081 retval = add_default_authorized_attributes(dev);
1082 if (retval)
1083 goto error;
1084 }
1085 return retval;
1086
1087error:
1088 usb_remove_sysfs_dev_files(dev: udev);
1089 return retval;
1090}
1091
1092void usb_remove_sysfs_dev_files(struct usb_device *udev)
1093{
1094 struct device *dev = &udev->dev;
1095
1096 if (is_root_hub(udev))
1097 remove_default_authorized_attributes(dev);
1098
1099 remove_power_attributes(dev);
1100 remove_persist_attributes(dev);
1101}
1102
1103/* Interface Association Descriptor fields */
1104#define usb_intf_assoc_attr(field, format_string) \
1105static ssize_t \
1106iad_##field##_show(struct device *dev, struct device_attribute *attr, \
1107 char *buf) \
1108{ \
1109 struct usb_interface *intf = to_usb_interface(dev); \
1110 \
1111 return sysfs_emit(buf, format_string, \
1112 intf->intf_assoc->field); \
1113} \
1114static DEVICE_ATTR_RO(iad_##field)
1115
1116usb_intf_assoc_attr(bFirstInterface, "%02x\n");
1117usb_intf_assoc_attr(bInterfaceCount, "%02d\n");
1118usb_intf_assoc_attr(bFunctionClass, "%02x\n");
1119usb_intf_assoc_attr(bFunctionSubClass, "%02x\n");
1120usb_intf_assoc_attr(bFunctionProtocol, "%02x\n");
1121
1122/* Interface fields */
1123#define usb_intf_attr(field, format_string) \
1124static ssize_t \
1125field##_show(struct device *dev, struct device_attribute *attr, \
1126 char *buf) \
1127{ \
1128 struct usb_interface *intf = to_usb_interface(dev); \
1129 \
1130 return sysfs_emit(buf, format_string, \
1131 intf->cur_altsetting->desc.field); \
1132} \
1133static DEVICE_ATTR_RO(field)
1134
1135usb_intf_attr(bInterfaceNumber, "%02x\n");
1136usb_intf_attr(bAlternateSetting, "%2d\n");
1137usb_intf_attr(bNumEndpoints, "%02x\n");
1138usb_intf_attr(bInterfaceClass, "%02x\n");
1139usb_intf_attr(bInterfaceSubClass, "%02x\n");
1140usb_intf_attr(bInterfaceProtocol, "%02x\n");
1141
1142static ssize_t interface_show(struct device *dev, struct device_attribute *attr,
1143 char *buf)
1144{
1145 struct usb_interface *intf;
1146 char *string;
1147
1148 intf = to_usb_interface(dev);
1149 string = READ_ONCE(intf->cur_altsetting->string);
1150 if (!string)
1151 return 0;
1152 return sysfs_emit(buf, fmt: "%s\n", string);
1153}
1154static DEVICE_ATTR_RO(interface);
1155
1156static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
1157 char *buf)
1158{
1159 struct usb_interface *intf;
1160 struct usb_device *udev;
1161 struct usb_host_interface *alt;
1162
1163 intf = to_usb_interface(dev);
1164 udev = interface_to_usbdev(intf);
1165 alt = READ_ONCE(intf->cur_altsetting);
1166
1167 return sysfs_emit(buf,
1168 fmt: "usb:v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02X"
1169 "ic%02Xisc%02Xip%02Xin%02X\n",
1170 le16_to_cpu(udev->descriptor.idVendor),
1171 le16_to_cpu(udev->descriptor.idProduct),
1172 le16_to_cpu(udev->descriptor.bcdDevice),
1173 udev->descriptor.bDeviceClass,
1174 udev->descriptor.bDeviceSubClass,
1175 udev->descriptor.bDeviceProtocol,
1176 alt->desc.bInterfaceClass,
1177 alt->desc.bInterfaceSubClass,
1178 alt->desc.bInterfaceProtocol,
1179 alt->desc.bInterfaceNumber);
1180}
1181static DEVICE_ATTR_RO(modalias);
1182
1183static ssize_t supports_autosuspend_show(struct device *dev,
1184 struct device_attribute *attr,
1185 char *buf)
1186{
1187 int s;
1188
1189 s = device_lock_interruptible(dev);
1190 if (s < 0)
1191 return -EINTR;
1192 /* Devices will be autosuspended even when an interface isn't claimed */
1193 s = (!dev->driver || to_usb_driver(dev->driver)->supports_autosuspend);
1194 device_unlock(dev);
1195
1196 return sysfs_emit(buf, fmt: "%u\n", s);
1197}
1198static DEVICE_ATTR_RO(supports_autosuspend);
1199
1200/*
1201 * interface_authorized_show - show authorization status of an USB interface
1202 * 1 is authorized, 0 is deauthorized
1203 */
1204static ssize_t interface_authorized_show(struct device *dev,
1205 struct device_attribute *attr, char *buf)
1206{
1207 struct usb_interface *intf = to_usb_interface(dev);
1208
1209 return sysfs_emit(buf, fmt: "%u\n", intf->authorized);
1210}
1211
1212/*
1213 * interface_authorized_store - authorize or deauthorize an USB interface
1214 */
1215static ssize_t interface_authorized_store(struct device *dev,
1216 struct device_attribute *attr, const char *buf, size_t count)
1217{
1218 struct usb_interface *intf = to_usb_interface(dev);
1219 bool val;
1220 struct kernfs_node *kn;
1221
1222 if (kstrtobool(s: buf, res: &val) != 0)
1223 return -EINVAL;
1224
1225 if (val) {
1226 usb_authorize_interface(intf);
1227 } else {
1228 /*
1229 * Prevent deadlock if another process is concurrently
1230 * trying to unregister intf.
1231 */
1232 kn = sysfs_break_active_protection(kobj: &dev->kobj, attr: &attr->attr);
1233 if (kn) {
1234 usb_deauthorize_interface(intf);
1235 sysfs_unbreak_active_protection(kn);
1236 }
1237 }
1238
1239 return count;
1240}
1241static struct device_attribute dev_attr_interface_authorized =
1242 __ATTR(authorized, S_IRUGO | S_IWUSR,
1243 interface_authorized_show, interface_authorized_store);
1244
1245static struct attribute *intf_attrs[] = {
1246 &dev_attr_bInterfaceNumber.attr,
1247 &dev_attr_bAlternateSetting.attr,
1248 &dev_attr_bNumEndpoints.attr,
1249 &dev_attr_bInterfaceClass.attr,
1250 &dev_attr_bInterfaceSubClass.attr,
1251 &dev_attr_bInterfaceProtocol.attr,
1252 &dev_attr_modalias.attr,
1253 &dev_attr_supports_autosuspend.attr,
1254 &dev_attr_interface_authorized.attr,
1255 NULL,
1256};
1257static const struct attribute_group intf_attr_grp = {
1258 .attrs = intf_attrs,
1259};
1260
1261static struct attribute *intf_assoc_attrs[] = {
1262 &dev_attr_iad_bFirstInterface.attr,
1263 &dev_attr_iad_bInterfaceCount.attr,
1264 &dev_attr_iad_bFunctionClass.attr,
1265 &dev_attr_iad_bFunctionSubClass.attr,
1266 &dev_attr_iad_bFunctionProtocol.attr,
1267 NULL,
1268};
1269
1270static umode_t intf_assoc_attrs_are_visible(struct kobject *kobj,
1271 struct attribute *a, int n)
1272{
1273 struct device *dev = kobj_to_dev(kobj);
1274 struct usb_interface *intf = to_usb_interface(dev);
1275
1276 if (intf->intf_assoc == NULL)
1277 return 0;
1278 return a->mode;
1279}
1280
1281static const struct attribute_group intf_assoc_attr_grp = {
1282 .attrs = intf_assoc_attrs,
1283 .is_visible = intf_assoc_attrs_are_visible,
1284};
1285
1286static ssize_t wireless_status_show(struct device *dev,
1287 struct device_attribute *attr, char *buf)
1288{
1289 struct usb_interface *intf;
1290
1291 intf = to_usb_interface(dev);
1292 if (intf->wireless_status == USB_WIRELESS_STATUS_DISCONNECTED)
1293 return sysfs_emit(buf, fmt: "%s\n", "disconnected");
1294 return sysfs_emit(buf, fmt: "%s\n", "connected");
1295}
1296static DEVICE_ATTR_RO(wireless_status);
1297
1298static struct attribute *intf_wireless_status_attrs[] = {
1299 &dev_attr_wireless_status.attr,
1300 NULL
1301};
1302
1303static umode_t intf_wireless_status_attr_is_visible(struct kobject *kobj,
1304 struct attribute *a, int n)
1305{
1306 struct device *dev = kobj_to_dev(kobj);
1307 struct usb_interface *intf = to_usb_interface(dev);
1308
1309 if (a != &dev_attr_wireless_status.attr ||
1310 intf->wireless_status != USB_WIRELESS_STATUS_NA)
1311 return a->mode;
1312 return 0;
1313}
1314
1315static const struct attribute_group intf_wireless_status_attr_grp = {
1316 .attrs = intf_wireless_status_attrs,
1317 .is_visible = intf_wireless_status_attr_is_visible,
1318};
1319
1320int usb_update_wireless_status_attr(struct usb_interface *intf)
1321{
1322 struct device *dev = &intf->dev;
1323 int ret;
1324
1325 ret = sysfs_update_group(kobj: &dev->kobj, grp: &intf_wireless_status_attr_grp);
1326 if (ret < 0)
1327 return ret;
1328
1329 sysfs_notify(kobj: &dev->kobj, NULL, attr: "wireless_status");
1330 kobject_uevent(kobj: &dev->kobj, action: KOBJ_CHANGE);
1331
1332 return 0;
1333}
1334
1335const struct attribute_group *usb_interface_groups[] = {
1336 &intf_attr_grp,
1337 &intf_assoc_attr_grp,
1338 &intf_wireless_status_attr_grp,
1339 NULL
1340};
1341
1342void usb_create_sysfs_intf_files(struct usb_interface *intf)
1343{
1344 struct usb_device *udev = interface_to_usbdev(intf);
1345 struct usb_host_interface *alt = intf->cur_altsetting;
1346
1347 if (intf->sysfs_files_created || intf->unregistering)
1348 return;
1349
1350 if (!alt->string && !(udev->quirks & USB_QUIRK_CONFIG_INTF_STRINGS))
1351 alt->string = usb_cache_string(udev, index: alt->desc.iInterface);
1352 if (alt->string && device_create_file(device: &intf->dev, entry: &dev_attr_interface)) {
1353 /* This is not a serious error */
1354 dev_dbg(&intf->dev, "interface string descriptor file not created\n");
1355 }
1356 intf->sysfs_files_created = 1;
1357}
1358
1359void usb_remove_sysfs_intf_files(struct usb_interface *intf)
1360{
1361 if (!intf->sysfs_files_created)
1362 return;
1363
1364 device_remove_file(dev: &intf->dev, attr: &dev_attr_interface);
1365 intf->sysfs_files_created = 0;
1366}
1367

source code of linux/drivers/usb/core/sysfs.c