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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 <mika.westerberg@linux.intel.com>
7 * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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 = sprintf(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 sprintf(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 sprintf(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, ¬_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 sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
403}
404static DEVICE_ATTR_RO(hid);
405
406static ssize_t uid_show(struct device *dev,
407 struct device_attribute *attr, char *buf)
408{
409 struct acpi_device *acpi_dev = to_acpi_device(dev);
410
411 return sprintf(buf, "%s\n", acpi_device_uid(acpi_dev));
412}
413static DEVICE_ATTR_RO(uid);
414
415static ssize_t adr_show(struct device *dev,
416 struct device_attribute *attr, char *buf)
417{
418 struct acpi_device *acpi_dev = to_acpi_device(dev);
419
420 if (acpi_dev->pnp.bus_address > U32_MAX)
421 return sprintf(buf, "0x%016llx\n", acpi_dev->pnp.bus_address);
422 else
423 return sprintf(buf, "0x%08llx\n", acpi_dev->pnp.bus_address);
424}
425static DEVICE_ATTR_RO(adr);
426
427static ssize_t path_show(struct device *dev,
428 struct device_attribute *attr, char *buf)
429{
430 struct acpi_device *acpi_dev = to_acpi_device(dev);
431
432 return acpi_object_path(acpi_dev->handle, buf);
433}
434static DEVICE_ATTR_RO(path);
435
436/* sysfs file that shows description text from the ACPI _STR method */
437static ssize_t description_show(struct device *dev,
438 struct device_attribute *attr,
439 char *buf)
440{
441 struct acpi_device *acpi_dev = to_acpi_device(dev);
442 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
443 union acpi_object *str_obj;
444 acpi_status status;
445 int result;
446
447 status = acpi_evaluate_object_typed(acpi_dev->handle, "_STR",
448 NULL, &buffer,
449 ACPI_TYPE_BUFFER);
450 if (ACPI_FAILURE(status))
451 return -EIO;
452
453 str_obj = buffer.pointer;
454
455 /*
456 * The _STR object contains a Unicode identifier for a device.
457 * We need to convert to utf-8 so it can be displayed.
458 */
459 result = utf16s_to_utf8s(
460 (wchar_t *)str_obj->buffer.pointer,
461 str_obj->buffer.length,
462 UTF16_LITTLE_ENDIAN, buf,
463 PAGE_SIZE - 1);
464
465 buf[result++] = '\n';
466
467 kfree(str_obj);
468
469 return result;
470}
471static DEVICE_ATTR_RO(description);
472
473static ssize_t
474sun_show(struct device *dev, struct device_attribute *attr,
475 char *buf)
476{
477 struct acpi_device *acpi_dev = to_acpi_device(dev);
478 acpi_status status;
479 unsigned long long sun;
480
481 status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
482 if (ACPI_FAILURE(status))
483 return -EIO;
484
485 return sprintf(buf, "%llu\n", sun);
486}
487static DEVICE_ATTR_RO(sun);
488
489static ssize_t
490hrv_show(struct device *dev, struct device_attribute *attr,
491 char *buf)
492{
493 struct acpi_device *acpi_dev = to_acpi_device(dev);
494 acpi_status status;
495 unsigned long long hrv;
496
497 status = acpi_evaluate_integer(acpi_dev->handle, "_HRV", NULL, &hrv);
498 if (ACPI_FAILURE(status))
499 return -EIO;
500
501 return sprintf(buf, "%llu\n", hrv);
502}
503static DEVICE_ATTR_RO(hrv);
504
505static ssize_t status_show(struct device *dev, struct device_attribute *attr,
506 char *buf)
507{
508 struct acpi_device *acpi_dev = to_acpi_device(dev);
509 acpi_status status;
510 unsigned long long sta;
511
512 status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
513 if (ACPI_FAILURE(status))
514 return -EIO;
515
516 return sprintf(buf, "%llu\n", sta);
517}
518static DEVICE_ATTR_RO(status);
519
520static struct attribute *acpi_attrs[] = {
521 &dev_attr_path.attr,
522 &dev_attr_hid.attr,
523 &dev_attr_modalias.attr,
524 &dev_attr_description.attr,
525 &dev_attr_adr.attr,
526 &dev_attr_uid.attr,
527 &dev_attr_sun.attr,
528 &dev_attr_hrv.attr,
529 &dev_attr_status.attr,
530 &dev_attr_eject.attr,
531 &dev_attr_power_state.attr,
532 &dev_attr_real_power_state.attr,
533 NULL
534};
535
536static bool acpi_show_attr(struct acpi_device *dev, const struct device_attribute *attr)
537{
538 /*
539 * Devices gotten from FADT don't have a "path" attribute
540 */
541 if (attr == &dev_attr_path)
542 return dev->handle;
543
544 if (attr == &dev_attr_hid || attr == &dev_attr_modalias)
545 return !list_empty(&dev->pnp.ids);
546
547 if (attr == &dev_attr_description)
548 return acpi_has_method(dev->handle, "_STR");
549
550 if (attr == &dev_attr_adr)
551 return dev->pnp.type.bus_address;
552
553 if (attr == &dev_attr_uid)
554 return acpi_device_uid(dev);
555
556 if (attr == &dev_attr_sun)
557 return acpi_has_method(dev->handle, "_SUN");
558
559 if (attr == &dev_attr_hrv)
560 return acpi_has_method(dev->handle, "_HRV");
561
562 if (attr == &dev_attr_status)
563 return acpi_has_method(dev->handle, "_STA");
564
565 /*
566 * If device has _EJ0, 'eject' file is created that is used to trigger
567 * hot-removal function from userland.
568 */
569 if (attr == &dev_attr_eject)
570 return acpi_has_method(dev->handle, "_EJ0");
571
572 if (attr == &dev_attr_power_state)
573 return dev->flags.power_manageable;
574
575 if (attr == &dev_attr_real_power_state)
576 return dev->flags.power_manageable && dev->power.flags.power_resources;
577
578 dev_warn_once(&dev->dev, "Unexpected attribute: %s\n", attr->attr.name);
579 return false;
580}
581
582static umode_t acpi_attr_is_visible(struct kobject *kobj,
583 struct attribute *attr,
584 int attrno)
585{
586 struct acpi_device *dev = to_acpi_device(kobj_to_dev(kobj));
587
588 if (acpi_show_attr(dev, container_of(attr, struct device_attribute, attr)))
589 return attr->mode;
590 else
591 return 0;
592}
593
594static const struct attribute_group acpi_group = {
595 .attrs = acpi_attrs,
596 .is_visible = acpi_attr_is_visible,
597};
598
599const struct attribute_group *acpi_groups[] = {
600 &acpi_group,
601 NULL
602};
603
604/**
605 * acpi_device_setup_files - Create sysfs attributes of an ACPI device.
606 * @dev: ACPI device object.
607 */
608void acpi_device_setup_files(struct acpi_device *dev)
609{
610 acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data);
611}
612
613/**
614 * acpi_device_remove_files - Remove sysfs attributes of an ACPI device.
615 * @dev: ACPI device object.
616 */
617void acpi_device_remove_files(struct acpi_device *dev)
618{
619 acpi_hide_nondev_subnodes(&dev->data);
620}