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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * drivers/acpi/device_sysfs.c - ACPI device sysfs attributes and modalias.
4 *
5 * Copyright (C) 2015, Intel Corp.
6 * Author: Mika Westerberg <[email protected]>
7 * Author: Rafael J. Wysocki <[email protected]>
8 *
9 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
10 *
11 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
12 */
13
14#include <linux/acpi.h>
15#include <linux/device.h>
16#include <linux/export.h>
17#include <linux/nls.h>
18
19#include "internal.h"
20
21static ssize_t acpi_object_path(acpi_handle handle, char *buf)
22{
23 struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
24 int result;
25
26 result = acpi_get_name(handle, ACPI_FULL_PATHNAME, &path);
27 if (result)
28 return result;
29
30 result = sysfs_emit(buf, "%s\n", (char *)path.pointer);
31 kfree(path.pointer);
32 return result;
33}
34
35struct acpi_data_node_attr {
36 struct attribute attr;
37 ssize_t (*show)(struct acpi_data_node *, char *);
38 ssize_t (*store)(struct acpi_data_node *, const char *, size_t count);
39};
40
41#define DATA_NODE_ATTR(_name) \
42 static struct acpi_data_node_attr data_node_##_name = \
43 __ATTR(_name, 0444, data_node_show_##_name, NULL)
44
45static ssize_t data_node_show_path(struct acpi_data_node *dn, char *buf)
46{
47 return dn->handle ? acpi_object_path(dn->handle, buf) : 0;
48}
49
50DATA_NODE_ATTR(path);
51
52static struct attribute *acpi_data_node_default_attrs[] = {
53 &data_node_path.attr,
54 NULL
55};
56ATTRIBUTE_GROUPS(acpi_data_node_default);
57
58#define to_data_node(k) container_of(k, struct acpi_data_node, kobj)
59#define to_attr(a) container_of(a, struct acpi_data_node_attr, attr)
60
61static ssize_t acpi_data_node_attr_show(struct kobject *kobj,
62 struct attribute *attr, char *buf)
63{
64 struct acpi_data_node *dn = to_data_node(kobj);
65 struct acpi_data_node_attr *dn_attr = to_attr(attr);
66
67 return dn_attr->show ? dn_attr->show(dn, buf) : -ENXIO;
68}
69
70static const struct sysfs_ops acpi_data_node_sysfs_ops = {
71 .show = acpi_data_node_attr_show,
72};
73
74static void acpi_data_node_release(struct kobject *kobj)
75{
76 struct acpi_data_node *dn = to_data_node(kobj);
77
78 complete(&dn->kobj_done);
79}
80
81static const struct kobj_type acpi_data_node_ktype = {
82 .sysfs_ops = &acpi_data_node_sysfs_ops,
83 .default_groups = acpi_data_node_default_groups,
84 .release = acpi_data_node_release,
85};
86
87static void acpi_expose_nondev_subnodes(struct kobject *kobj,
88 struct acpi_device_data *data)
89{
90 struct list_head *list = &data->subnodes;
91 struct acpi_data_node *dn;
92
93 if (list_empty(list))
94 return;
95
96 list_for_each_entry(dn, list, sibling) {
97 int ret;
98
99 init_completion(&dn->kobj_done);
100 ret = kobject_init_and_add(&dn->kobj, &acpi_data_node_ktype,
101 kobj, "%s", dn->name);
102 if (!ret)
103 acpi_expose_nondev_subnodes(&dn->kobj, &dn->data);
104 else if (dn->handle)
105 acpi_handle_err(dn->handle, "Failed to expose (%d)\n", ret);
106 }
107}
108
109static void acpi_hide_nondev_subnodes(struct acpi_device_data *data)
110{
111 struct list_head *list = &data->subnodes;
112 struct acpi_data_node *dn;
113
114 if (list_empty(list))
115 return;
116
117 list_for_each_entry_reverse(dn, list, sibling) {
118 acpi_hide_nondev_subnodes(&dn->data);
119 kobject_put(&dn->kobj);
120 }
121}
122
123/**
124 * create_pnp_modalias - Create hid/cid(s) string for modalias and uevent
125 * @acpi_dev: ACPI device object.
126 * @modalias: Buffer to print into.
127 * @size: Size of the buffer.
128 *
129 * Creates hid/cid(s) string needed for modalias and uevent
130 * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
131 * char *modalias: "acpi:IBM0001:ACPI0001"
132 * Return: 0: no _HID and no _CID
133 * -EINVAL: output error
134 * -ENOMEM: output is truncated
135 */
136static int create_pnp_modalias(const struct acpi_device *acpi_dev, char *modalias,
137 int size)
138{
139 int len;
140 int count;
141 struct acpi_hardware_id *id;
142
143 /* Avoid unnecessarily loading modules for non present devices. */
144 if (!acpi_device_is_present(acpi_dev))
145 return 0;
146
147 /*
148 * Since we skip ACPI_DT_NAMESPACE_HID from the modalias below, 0 should
149 * be returned if ACPI_DT_NAMESPACE_HID is the only ACPI/PNP ID in the
150 * device's list.
151 */
152 count = 0;
153 list_for_each_entry(id, &acpi_dev->pnp.ids, list)
154 if (strcmp(id->id, ACPI_DT_NAMESPACE_HID))
155 count++;
156
157 if (!count)
158 return 0;
159
160 len = snprintf(modalias, size, "acpi:");
161 if (len >= size)
162 return -ENOMEM;
163
164 size -= len;
165
166 list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
167 if (!strcmp(id->id, ACPI_DT_NAMESPACE_HID))
168 continue;
169
170 count = snprintf(&modalias[len], size, "%s:", id->id);
171
172 if (count >= size)
173 return -ENOMEM;
174
175 len += count;
176 size -= count;
177 }
178
179 return len;
180}
181
182/**
183 * create_of_modalias - Creates DT compatible string for modalias and uevent
184 * @acpi_dev: ACPI device object.
185 * @modalias: Buffer to print into.
186 * @size: Size of the buffer.
187 *
188 * Expose DT compatible modalias as of:NnameTCcompatible. This function should
189 * only be called for devices having ACPI_DT_NAMESPACE_HID in their list of
190 * ACPI/PNP IDs.
191 */
192static int create_of_modalias(const struct acpi_device *acpi_dev, char *modalias,
193 int size)
194{
195 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
196 const union acpi_object *of_compatible, *obj;
197 acpi_status status;
198 int len, count;
199 int i, nval;
200 char *c;
201
202 status = acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf);
203 if (ACPI_FAILURE(status))
204 return -ENODEV;
205
206 /* DT strings are all in lower case */
207 for (c = buf.pointer; *c != '\0'; c++)
208 *c = tolower(*c);
209
210 len = snprintf(modalias, size, "of:N%sT", (char *)buf.pointer);
211 ACPI_FREE(buf.pointer);
212
213 if (len >= size)
214 return -ENOMEM;
215
216 size -= len;
217
218 of_compatible = acpi_dev->data.of_compatible;
219 if (of_compatible->type == ACPI_TYPE_PACKAGE) {
220 nval = of_compatible->package.count;
221 obj = of_compatible->package.elements;
222 } else { /* Must be ACPI_TYPE_STRING. */
223 nval = 1;
224 obj = of_compatible;
225 }
226 for (i = 0; i < nval; i++, obj++) {
227 count = snprintf(&modalias[len], size, "C%s",
228 obj->string.pointer);
229
230 if (count >= size)
231 return -ENOMEM;
232
233 len += count;
234 size -= count;
235 }
236
237 return len;
238}
239
240int __acpi_device_uevent_modalias(const struct acpi_device *adev,
241 struct kobj_uevent_env *env)
242{
243 int len;
244
245 if (!adev)
246 return -ENODEV;
247
248 if (list_empty(&adev->pnp.ids))
249 return 0;
250
251 if (add_uevent_var(env, "MODALIAS="))
252 return -ENOMEM;
253
254 if (adev->data.of_compatible)
255 len = create_of_modalias(adev, &env->buf[env->buflen - 1],
256 sizeof(env->buf) - env->buflen);
257 else
258 len = create_pnp_modalias(adev, &env->buf[env->buflen - 1],
259 sizeof(env->buf) - env->buflen);
260 if (len < 0)
261 return len;
262
263 env->buflen += len;
264
265 return 0;
266}
267
268/**
269 * acpi_device_uevent_modalias - uevent modalias for ACPI-enumerated devices.
270 * @dev: Struct device to get ACPI device node.
271 * @env: Environment variables of the kobject uevent.
272 *
273 * Create the uevent modalias field for ACPI-enumerated devices.
274 *
275 * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
276 * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
277 */
278int acpi_device_uevent_modalias(const struct device *dev, struct kobj_uevent_env *env)
279{
280 return __acpi_device_uevent_modalias(acpi_companion_match(dev), env);
281}
282EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
283
284static int __acpi_device_modalias(const struct acpi_device *adev, char *buf, int size)
285{
286 int len, count;
287
288 if (!adev)
289 return -ENODEV;
290
291 if (list_empty(&adev->pnp.ids))
292 return 0;
293
294 len = create_pnp_modalias(adev, buf, size - 1);
295 if (len < 0) {
296 return len;
297 } else if (len > 0) {
298 buf[len++] = '\n';
299 size -= len;
300 }
301 if (!adev->data.of_compatible)
302 return len;
303
304 count = create_of_modalias(adev, buf + len, size - 1);
305 if (count < 0) {
306 return count;
307 } else if (count > 0) {
308 len += count;
309 buf[len++] = '\n';
310 }
311
312 return len;
313}
314
315/**
316 * acpi_device_modalias - modalias sysfs attribute for ACPI-enumerated devices.
317 * @dev: Struct device to get ACPI device node.
318 * @buf: The buffer to save pnp_modalias and of_modalias.
319 * @size: Size of buffer.
320 *
321 * Create the modalias sysfs attribute for ACPI-enumerated devices.
322 *
323 * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
324 * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
325 */
326int acpi_device_modalias(struct device *dev, char *buf, int size)
327{
328 return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
329}
330EXPORT_SYMBOL_GPL(acpi_device_modalias);
331
332static ssize_t
333modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
334{
335 return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
336}
337static DEVICE_ATTR_RO(modalias);
338
339static ssize_t real_power_state_show(struct device *dev,
340 struct device_attribute *attr, char *buf)
341{
342 struct acpi_device *adev = to_acpi_device(dev);
343 int state;
344 int ret;
345
346 ret = acpi_device_get_power(adev, &state);
347 if (ret)
348 return ret;
349
350 return sysfs_emit(buf, "%s\n", acpi_power_state_string(state));
351}
352
353static DEVICE_ATTR_RO(real_power_state);
354
355static ssize_t power_state_show(struct device *dev,
356 struct device_attribute *attr, char *buf)
357{
358 struct acpi_device *adev = to_acpi_device(dev);
359
360 return sysfs_emit(buf, "%s\n", acpi_power_state_string(adev->power.state));
361}
362
363static DEVICE_ATTR_RO(power_state);
364
365static ssize_t
366eject_store(struct device *d, struct device_attribute *attr,
367 const char *buf, size_t count)
368{
369 struct acpi_device *acpi_device = to_acpi_device(d);
370 acpi_object_type not_used;
371 acpi_status status;
372
373 if (!count || buf[0] != '1')
374 return -EINVAL;
375
376 if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
377 && !d->driver)
378 return -ENODEV;
379
380 status = acpi_get_type(acpi_device->handle, &not_used);
381 if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
382 return -ENODEV;
383
384 acpi_dev_get(acpi_device);
385 status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
386 if (ACPI_SUCCESS(status))
387 return count;
388
389 acpi_dev_put(acpi_device);
390 acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
391 ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
392 return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
393}
394
395static DEVICE_ATTR_WO(eject);
396
397static ssize_t
398hid_show(struct device *dev, struct device_attribute *attr, char *buf)
399{
400 struct acpi_device *acpi_dev = to_acpi_device(dev);
401
402 return sysfs_emit(buf, "%s\n", acpi_device_hid(acpi_dev));
403}
404static DEVICE_ATTR_RO(hid);
405
406static ssize_t cid_show(struct device *dev, struct device_attribute *attr,
407 char *buf)
408{
409 struct acpi_device *acpi_dev = to_acpi_device(dev);
410 struct acpi_device_info *info = NULL;
411 ssize_t len = 0;
412
413 acpi_get_object_info(acpi_dev->handle, &info);
414 if (!info)
415 return 0;
416
417 if (info->valid & ACPI_VALID_CID) {
418 struct acpi_pnp_device_id_list *cid_list = &info->compatible_id_list;
419 int i;
420
421 for (i = 0; i < cid_list->count - 1; i++)
422 len += sysfs_emit_at(buf, len, "%s,", cid_list->ids[i].string);
423
424 len += sysfs_emit_at(buf, len, "%s\n", cid_list->ids[i].string);
425 }
426
427 kfree(info);
428
429 return len;
430}
431static DEVICE_ATTR_RO(cid);
432
433static ssize_t uid_show(struct device *dev,
434 struct device_attribute *attr, char *buf)
435{
436 struct acpi_device *acpi_dev = to_acpi_device(dev);
437
438 return sysfs_emit(buf, "%s\n", acpi_device_uid(acpi_dev));
439}
440static DEVICE_ATTR_RO(uid);
441
442static ssize_t adr_show(struct device *dev,
443 struct device_attribute *attr, char *buf)
444{
445 struct acpi_device *acpi_dev = to_acpi_device(dev);
446
447 if (acpi_dev->pnp.bus_address > U32_MAX)
448 return sysfs_emit(buf, "0x%016llx\n", acpi_dev->pnp.bus_address);
449 else
450 return sysfs_emit(buf, "0x%08llx\n", acpi_dev->pnp.bus_address);
451}
452static DEVICE_ATTR_RO(adr);
453
454static ssize_t path_show(struct device *dev,
455 struct device_attribute *attr, char *buf)
456{
457 struct acpi_device *acpi_dev = to_acpi_device(dev);
458
459 return acpi_object_path(acpi_dev->handle, buf);
460}
461static DEVICE_ATTR_RO(path);
462
463/* sysfs file that shows description text from the ACPI _STR method */
464static ssize_t description_show(struct device *dev,
465 struct device_attribute *attr,
466 char *buf)
467{
468 struct acpi_device *acpi_dev = to_acpi_device(dev);
469 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
470 union acpi_object *str_obj;
471 acpi_status status;
472 int result;
473
474 status = acpi_evaluate_object_typed(acpi_dev->handle, "_STR",
475 NULL, &buffer,
476 ACPI_TYPE_BUFFER);
477 if (ACPI_FAILURE(status))
478 return -EIO;
479
480 str_obj = buffer.pointer;
481
482 /*
483 * The _STR object contains a Unicode identifier for a device.
484 * We need to convert to utf-8 so it can be displayed.
485 */
486 result = utf16s_to_utf8s(
487 (wchar_t *)str_obj->buffer.pointer,
488 str_obj->buffer.length,
489 UTF16_LITTLE_ENDIAN, buf,
490 PAGE_SIZE - 1);
491
492 buf[result++] = '\n';
493
494 ACPI_FREE(str_obj);
495
496 return result;
497}
498static DEVICE_ATTR_RO(description);
499
500static ssize_t
501sun_show(struct device *dev, struct device_attribute *attr,
502 char *buf)
503{
504 struct acpi_device *acpi_dev = to_acpi_device(dev);
505 acpi_status status;
506 unsigned long long sun;
507
508 status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
509 if (ACPI_FAILURE(status))
510 return -EIO;
511
512 return sysfs_emit(buf, "%llu\n", sun);
513}
514static DEVICE_ATTR_RO(sun);
515
516static ssize_t
517hrv_show(struct device *dev, struct device_attribute *attr,
518 char *buf)
519{
520 struct acpi_device *acpi_dev = to_acpi_device(dev);
521 acpi_status status;
522 unsigned long long hrv;
523
524 status = acpi_evaluate_integer(acpi_dev->handle, "_HRV", NULL, &hrv);
525 if (ACPI_FAILURE(status))
526 return -EIO;
527
528 return sysfs_emit(buf, "%llu\n", hrv);
529}
530static DEVICE_ATTR_RO(hrv);
531
532static ssize_t status_show(struct device *dev, struct device_attribute *attr,
533 char *buf)
534{
535 struct acpi_device *acpi_dev = to_acpi_device(dev);
536 acpi_status status;
537 unsigned long long sta;
538
539 status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
540 if (ACPI_FAILURE(status))
541 return -EIO;
542
543 return sysfs_emit(buf, "%llu\n", sta);
544}
545static DEVICE_ATTR_RO(status);
546
547static struct attribute *acpi_attrs[] = {
548 &dev_attr_path.attr,
549 &dev_attr_hid.attr,
550 &dev_attr_cid.attr,
551 &dev_attr_modalias.attr,
552 &dev_attr_description.attr,
553 &dev_attr_adr.attr,
554 &dev_attr_uid.attr,
555 &dev_attr_sun.attr,
556 &dev_attr_hrv.attr,
557 &dev_attr_status.attr,
558 &dev_attr_eject.attr,
559 &dev_attr_power_state.attr,
560 &dev_attr_real_power_state.attr,
561 NULL
562};
563
564static bool acpi_show_attr(struct acpi_device *dev, const struct device_attribute *attr)
565{
566 /*
567 * Devices gotten from FADT don't have a "path" attribute
568 */
569 if (attr == &dev_attr_path)
570 return dev->handle;
571
572 if (attr == &dev_attr_hid || attr == &dev_attr_modalias)
573 return !list_empty(&dev->pnp.ids);
574
575 if (attr == &dev_attr_description)
576 return acpi_has_method(dev->handle, "_STR");
577
578 if (attr == &dev_attr_adr)
579 return dev->pnp.type.bus_address;
580
581 if (attr == &dev_attr_uid)
582 return acpi_device_uid(dev);
583
584 if (attr == &dev_attr_sun)
585 return acpi_has_method(dev->handle, "_SUN");
586
587 if (attr == &dev_attr_hrv)
588 return acpi_has_method(dev->handle, "_HRV");
589
590 if (attr == &dev_attr_status)
591 return acpi_has_method(dev->handle, "_STA");
592
593 if (attr == &dev_attr_cid)
594 return acpi_has_method(dev->handle, "_CID");
595
596 /*
597 * If device has _EJ0, 'eject' file is created that is used to trigger
598 * hot-removal function from userland.
599 */
600 if (attr == &dev_attr_eject)
601 return acpi_has_method(dev->handle, "_EJ0");
602
603 if (attr == &dev_attr_power_state)
604 return dev->flags.power_manageable;
605
606 if (attr == &dev_attr_real_power_state)
607 return dev->flags.power_manageable && dev->power.flags.power_resources;
608
609 dev_warn_once(&dev->dev, "Unexpected attribute: %s\n", attr->attr.name);
610 return false;
611}
612
613static umode_t acpi_attr_is_visible(struct kobject *kobj,
614 struct attribute *attr,
615 int attrno)
616{
617 struct acpi_device *dev = to_acpi_device(kobj_to_dev(kobj));
618
619 if (acpi_show_attr(dev, container_of(attr, struct device_attribute, attr)))
620 return attr->mode;
621 else
622 return 0;
623}
624
625static const struct attribute_group acpi_group = {
626 .attrs = acpi_attrs,
627 .is_visible = acpi_attr_is_visible,
628};
629
630const struct attribute_group *acpi_groups[] = {
631 &acpi_group,
632 NULL
633};
634
635/**
636 * acpi_device_setup_files - Create sysfs attributes of an ACPI device.
637 * @dev: ACPI device object.
638 */
639void acpi_device_setup_files(struct acpi_device *dev)
640{
641 acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data);
642}
643
644/**
645 * acpi_device_remove_files - Remove sysfs attributes of an ACPI device.
646 * @dev: ACPI device object.
647 */
648void acpi_device_remove_files(struct acpi_device *dev)
649{
650 acpi_hide_nondev_subnodes(&dev->data);
651}