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(object: handle, ACPI_FULL_PATHNAME, ret_path_ptr: &path);
27 if (result)
28 return result;
29
30 result = sprintf(buf, fmt: "%s\n", (char *)path.pointer);
31 kfree(objp: 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(handle: 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(head: list))
94 return;
95
96 list_for_each_entry(dn, list, sibling) {
97 int ret;
98
99 init_completion(x: &dn->kobj_done);
100 ret = kobject_init_and_add(kobj: &dn->kobj, ktype: &acpi_data_node_ktype,
101 parent: kobj, fmt: "%s", dn->name);
102 if (!ret)
103 acpi_expose_nondev_subnodes(kobj: &dn->kobj, data: &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(head: list))
115 return;
116
117 list_for_each_entry_reverse(dn, list, sibling) {
118 acpi_hide_nondev_subnodes(data: &dn->data);
119 kobject_put(kobj: &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(adev: 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(buf: modalias, size, fmt: "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(buf: &modalias[len], size, fmt: "%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(object: acpi_dev->handle, ACPI_SINGLE_NAME, ret_path_ptr: &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(buf: modalias, size, fmt: "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(buf: &modalias[len], size, fmt: "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(head: &adev->pnp.ids))
249 return 0;
250
251 if (add_uevent_var(env, format: "MODALIAS="))
252 return -ENOMEM;
253
254 if (adev->data.of_compatible)
255 len = create_of_modalias(acpi_dev: adev, modalias: &env->buf[env->buflen - 1],
256 size: sizeof(env->buf) - env->buflen);
257 else
258 len = create_pnp_modalias(acpi_dev: adev, modalias: &env->buf[env->buflen - 1],
259 size: 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(adev: 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(head: &adev->pnp.ids))
292 return 0;
293
294 len = create_pnp_modalias(acpi_dev: adev, modalias: buf, size: 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(acpi_dev: adev, modalias: buf + len, size: 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(adev: 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, size: 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(device: adev, state: &state);
347 if (ret)
348 return ret;
349
350 return sprintf(buf, fmt: "%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, fmt: "%s\n", acpi_power_state_string(state: 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(object: acpi_device->handle, out_type: &not_used);
381 if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
382 return -ENODEV;
383
384 acpi_dev_get(adev: acpi_device);
385 status = acpi_hotplug_schedule(adev: acpi_device, ACPI_OST_EC_OSPM_EJECT);
386 if (ACPI_SUCCESS(status))
387 return count;
388
389 acpi_dev_put(adev: acpi_device);
390 acpi_evaluate_ost(handle: 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, fmt: "%s\n", acpi_device_hid(device: 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, fmt: "%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, fmt: "0x%016llx\n", acpi_dev->pnp.bus_address);
422 else
423 return sprintf(buf, fmt: "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(handle: 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 int result;
443
444 if (acpi_dev->pnp.str_obj == NULL)
445 return 0;
446
447 /*
448 * The _STR object contains a Unicode identifier for a device.
449 * We need to convert to utf-8 so it can be displayed.
450 */
451 result = utf16s_to_utf8s(
452 pwcs: (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
453 len: acpi_dev->pnp.str_obj->buffer.length,
454 endian: UTF16_LITTLE_ENDIAN, s: buf,
455 PAGE_SIZE - 1);
456
457 buf[result++] = '\n';
458
459 return result;
460}
461static DEVICE_ATTR_RO(description);
462
463static ssize_t
464sun_show(struct device *dev, struct device_attribute *attr,
465 char *buf)
466{
467 struct acpi_device *acpi_dev = to_acpi_device(dev);
468 acpi_status status;
469 unsigned long long sun;
470
471 status = acpi_evaluate_integer(handle: acpi_dev->handle, pathname: "_SUN", NULL, data: &sun);
472 if (ACPI_FAILURE(status))
473 return -EIO;
474
475 return sprintf(buf, fmt: "%llu\n", sun);
476}
477static DEVICE_ATTR_RO(sun);
478
479static ssize_t
480hrv_show(struct device *dev, struct device_attribute *attr,
481 char *buf)
482{
483 struct acpi_device *acpi_dev = to_acpi_device(dev);
484 acpi_status status;
485 unsigned long long hrv;
486
487 status = acpi_evaluate_integer(handle: acpi_dev->handle, pathname: "_HRV", NULL, data: &hrv);
488 if (ACPI_FAILURE(status))
489 return -EIO;
490
491 return sprintf(buf, fmt: "%llu\n", hrv);
492}
493static DEVICE_ATTR_RO(hrv);
494
495static ssize_t status_show(struct device *dev, struct device_attribute *attr,
496 char *buf)
497{
498 struct acpi_device *acpi_dev = to_acpi_device(dev);
499 acpi_status status;
500 unsigned long long sta;
501
502 status = acpi_evaluate_integer(handle: acpi_dev->handle, pathname: "_STA", NULL, data: &sta);
503 if (ACPI_FAILURE(status))
504 return -EIO;
505
506 return sprintf(buf, fmt: "%llu\n", sta);
507}
508static DEVICE_ATTR_RO(status);
509
510/**
511 * acpi_device_setup_files - Create sysfs attributes of an ACPI device.
512 * @dev: ACPI device object.
513 */
514int acpi_device_setup_files(struct acpi_device *dev)
515{
516 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
517 acpi_status status;
518 int result = 0;
519
520 /*
521 * Devices gotten from FADT don't have a "path" attribute
522 */
523 if (dev->handle) {
524 result = device_create_file(device: &dev->dev, entry: &dev_attr_path);
525 if (result)
526 goto end;
527 }
528
529 if (!list_empty(head: &dev->pnp.ids)) {
530 result = device_create_file(device: &dev->dev, entry: &dev_attr_hid);
531 if (result)
532 goto end;
533
534 result = device_create_file(device: &dev->dev, entry: &dev_attr_modalias);
535 if (result)
536 goto end;
537 }
538
539 /*
540 * If device has _STR, 'description' file is created
541 */
542 if (acpi_has_method(handle: dev->handle, name: "_STR")) {
543 status = acpi_evaluate_object(object: dev->handle, pathname: "_STR",
544 NULL, return_object_buffer: &buffer);
545 if (ACPI_FAILURE(status))
546 buffer.pointer = NULL;
547 dev->pnp.str_obj = buffer.pointer;
548 result = device_create_file(device: &dev->dev, entry: &dev_attr_description);
549 if (result)
550 goto end;
551 }
552
553 if (dev->pnp.type.bus_address)
554 result = device_create_file(device: &dev->dev, entry: &dev_attr_adr);
555 if (acpi_device_uid(dev))
556 result = device_create_file(device: &dev->dev, entry: &dev_attr_uid);
557
558 if (acpi_has_method(handle: dev->handle, name: "_SUN")) {
559 result = device_create_file(device: &dev->dev, entry: &dev_attr_sun);
560 if (result)
561 goto end;
562 }
563
564 if (acpi_has_method(handle: dev->handle, name: "_HRV")) {
565 result = device_create_file(device: &dev->dev, entry: &dev_attr_hrv);
566 if (result)
567 goto end;
568 }
569
570 if (acpi_has_method(handle: dev->handle, name: "_STA")) {
571 result = device_create_file(device: &dev->dev, entry: &dev_attr_status);
572 if (result)
573 goto end;
574 }
575
576 /*
577 * If device has _EJ0, 'eject' file is created that is used to trigger
578 * hot-removal function from userland.
579 */
580 if (acpi_has_method(handle: dev->handle, name: "_EJ0")) {
581 result = device_create_file(device: &dev->dev, entry: &dev_attr_eject);
582 if (result)
583 return result;
584 }
585
586 if (dev->flags.power_manageable) {
587 result = device_create_file(device: &dev->dev, entry: &dev_attr_power_state);
588 if (result)
589 return result;
590
591 if (dev->power.flags.power_resources)
592 result = device_create_file(device: &dev->dev,
593 entry: &dev_attr_real_power_state);
594 }
595
596 acpi_expose_nondev_subnodes(kobj: &dev->dev.kobj, data: &dev->data);
597
598end:
599 return result;
600}
601
602/**
603 * acpi_device_remove_files - Remove sysfs attributes of an ACPI device.
604 * @dev: ACPI device object.
605 */
606void acpi_device_remove_files(struct acpi_device *dev)
607{
608 acpi_hide_nondev_subnodes(data: &dev->data);
609
610 if (dev->flags.power_manageable) {
611 device_remove_file(dev: &dev->dev, attr: &dev_attr_power_state);
612 if (dev->power.flags.power_resources)
613 device_remove_file(dev: &dev->dev,
614 attr: &dev_attr_real_power_state);
615 }
616
617 /*
618 * If device has _STR, remove 'description' file
619 */
620 if (acpi_has_method(handle: dev->handle, name: "_STR")) {
621 kfree(objp: dev->pnp.str_obj);
622 device_remove_file(dev: &dev->dev, attr: &dev_attr_description);
623 }
624 /*
625 * If device has _EJ0, remove 'eject' file.
626 */
627 if (acpi_has_method(handle: dev->handle, name: "_EJ0"))
628 device_remove_file(dev: &dev->dev, attr: &dev_attr_eject);
629
630 if (acpi_has_method(handle: dev->handle, name: "_SUN"))
631 device_remove_file(dev: &dev->dev, attr: &dev_attr_sun);
632
633 if (acpi_has_method(handle: dev->handle, name: "_HRV"))
634 device_remove_file(dev: &dev->dev, attr: &dev_attr_hrv);
635
636 if (acpi_device_uid(dev))
637 device_remove_file(dev: &dev->dev, attr: &dev_attr_uid);
638 if (dev->pnp.type.bus_address)
639 device_remove_file(dev: &dev->dev, attr: &dev_attr_adr);
640 device_remove_file(dev: &dev->dev, attr: &dev_attr_modalias);
641 device_remove_file(dev: &dev->dev, attr: &dev_attr_hid);
642 if (acpi_has_method(handle: dev->handle, name: "_STA"))
643 device_remove_file(dev: &dev->dev, attr: &dev_attr_status);
644 if (dev->handle)
645 device_remove_file(dev: &dev->dev, attr: &dev_attr_path);
646}
647

source code of linux/drivers/acpi/device_sysfs.c