1 // SPDX-License-Identifier: GPL-2.0-only
3 * drivers/acpi/device_sysfs.c - ACPI device sysfs attributes and modalias.
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>
9 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
11 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
14 #include <linux/acpi.h>
15 #include <linux/device.h>
16 #include <linux/export.h>
17 #include <linux/nls.h>
21 static ssize_t acpi_object_path(acpi_handle handle, char *buf)
23 struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
26 result = acpi_get_name(handle, ACPI_FULL_PATHNAME, &path);
30 result = sprintf(buf, "%s\n", (char *)path.pointer);
35 struct 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);
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)
45 static ssize_t data_node_show_path(struct acpi_data_node *dn, char *buf)
47 return dn->handle ? acpi_object_path(dn->handle, buf) : 0;
52 static struct attribute *acpi_data_node_default_attrs[] = {
56 ATTRIBUTE_GROUPS(acpi_data_node_default);
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)
61 static ssize_t acpi_data_node_attr_show(struct kobject *kobj,
62 struct attribute *attr, char *buf)
64 struct acpi_data_node *dn = to_data_node(kobj);
65 struct acpi_data_node_attr *dn_attr = to_attr(attr);
67 return dn_attr->show ? dn_attr->show(dn, buf) : -ENXIO;
70 static const struct sysfs_ops acpi_data_node_sysfs_ops = {
71 .show = acpi_data_node_attr_show,
74 static void acpi_data_node_release(struct kobject *kobj)
76 struct acpi_data_node *dn = to_data_node(kobj);
78 complete(&dn->kobj_done);
81 static 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,
87 static void acpi_expose_nondev_subnodes(struct kobject *kobj,
88 struct acpi_device_data *data)
90 struct list_head *list = &data->subnodes;
91 struct acpi_data_node *dn;
96 list_for_each_entry(dn, list, sibling) {
99 init_completion(&dn->kobj_done);
100 ret = kobject_init_and_add(&dn->kobj, &acpi_data_node_ktype,
101 kobj, "%s", dn->name);
103 acpi_expose_nondev_subnodes(&dn->kobj, &dn->data);
105 acpi_handle_err(dn->handle, "Failed to expose (%d)\n", ret);
109 static void acpi_hide_nondev_subnodes(struct acpi_device_data *data)
111 struct list_head *list = &data->subnodes;
112 struct acpi_data_node *dn;
114 if (list_empty(list))
117 list_for_each_entry_reverse(dn, list, sibling) {
118 acpi_hide_nondev_subnodes(&dn->data);
119 kobject_put(&dn->kobj);
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.
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
136 static int create_pnp_modalias(const struct acpi_device *acpi_dev, char *modalias,
141 struct acpi_hardware_id *id;
143 /* Avoid unnecessarily loading modules for non present devices. */
144 if (!acpi_device_is_present(acpi_dev))
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
153 list_for_each_entry(id, &acpi_dev->pnp.ids, list)
154 if (strcmp(id->id, ACPI_DT_NAMESPACE_HID))
160 len = snprintf(modalias, size, "acpi:");
166 list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
167 if (!strcmp(id->id, ACPI_DT_NAMESPACE_HID))
170 count = snprintf(&modalias[len], size, "%s:", id->id);
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.
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
192 static int create_of_modalias(const struct acpi_device *acpi_dev, char *modalias,
195 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
196 const union acpi_object *of_compatible, *obj;
202 status = acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf);
203 if (ACPI_FAILURE(status))
206 /* DT strings are all in lower case */
207 for (c = buf.pointer; *c != '\0'; c++)
210 len = snprintf(modalias, size, "of:N%sT", (char *)buf.pointer);
211 ACPI_FREE(buf.pointer);
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. */
226 for (i = 0; i < nval; i++, obj++) {
227 count = snprintf(&modalias[len], size, "C%s",
228 obj->string.pointer);
240 int __acpi_device_uevent_modalias(const struct acpi_device *adev,
241 struct kobj_uevent_env *env)
248 if (list_empty(&adev->pnp.ids))
251 if (add_uevent_var(env, "MODALIAS="))
254 if (adev->data.of_compatible)
255 len = create_of_modalias(adev, &env->buf[env->buflen - 1],
256 sizeof(env->buf) - env->buflen);
258 len = create_pnp_modalias(adev, &env->buf[env->buflen - 1],
259 sizeof(env->buf) - env->buflen);
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.
273 * Create the uevent modalias field for ACPI-enumerated devices.
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".
278 int acpi_device_uevent_modalias(const struct device *dev, struct kobj_uevent_env *env)
280 return __acpi_device_uevent_modalias(acpi_companion_match(dev), env);
282 EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
284 static int __acpi_device_modalias(const struct acpi_device *adev, char *buf, int size)
291 if (list_empty(&adev->pnp.ids))
294 len = create_pnp_modalias(adev, buf, size - 1);
297 } else if (len > 0) {
301 if (!adev->data.of_compatible)
304 count = create_of_modalias(adev, buf + len, size - 1);
307 } else if (count > 0) {
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.
321 * Create the modalias sysfs attribute for ACPI-enumerated devices.
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".
326 int acpi_device_modalias(struct device *dev, char *buf, int size)
328 return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
330 EXPORT_SYMBOL_GPL(acpi_device_modalias);
333 modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
335 return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
337 static DEVICE_ATTR_RO(modalias);
339 static ssize_t real_power_state_show(struct device *dev,
340 struct device_attribute *attr, char *buf)
342 struct acpi_device *adev = to_acpi_device(dev);
346 ret = acpi_device_get_power(adev, &state);
350 return sprintf(buf, "%s\n", acpi_power_state_string(state));
353 static DEVICE_ATTR_RO(real_power_state);
355 static ssize_t power_state_show(struct device *dev,
356 struct device_attribute *attr, char *buf)
358 struct acpi_device *adev = to_acpi_device(dev);
360 return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
363 static DEVICE_ATTR_RO(power_state);
366 eject_store(struct device *d, struct device_attribute *attr,
367 const char *buf, size_t count)
369 struct acpi_device *acpi_device = to_acpi_device(d);
370 acpi_object_type not_used;
373 if (!count || buf[0] != '1')
376 if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
380 status = acpi_get_type(acpi_device->handle, ¬_used);
381 if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
384 acpi_dev_get(acpi_device);
385 status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
386 if (ACPI_SUCCESS(status))
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;
395 static DEVICE_ATTR_WO(eject);
398 hid_show(struct device *dev, struct device_attribute *attr, char *buf)
400 struct acpi_device *acpi_dev = to_acpi_device(dev);
402 return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
404 static DEVICE_ATTR_RO(hid);
406 static ssize_t uid_show(struct device *dev,
407 struct device_attribute *attr, char *buf)
409 struct acpi_device *acpi_dev = to_acpi_device(dev);
411 return sprintf(buf, "%s\n", acpi_device_uid(acpi_dev));
413 static DEVICE_ATTR_RO(uid);
415 static ssize_t adr_show(struct device *dev,
416 struct device_attribute *attr, char *buf)
418 struct acpi_device *acpi_dev = to_acpi_device(dev);
420 if (acpi_dev->pnp.bus_address > U32_MAX)
421 return sprintf(buf, "0x%016llx\n", acpi_dev->pnp.bus_address);
423 return sprintf(buf, "0x%08llx\n", acpi_dev->pnp.bus_address);
425 static DEVICE_ATTR_RO(adr);
427 static ssize_t path_show(struct device *dev,
428 struct device_attribute *attr, char *buf)
430 struct acpi_device *acpi_dev = to_acpi_device(dev);
432 return acpi_object_path(acpi_dev->handle, buf);
434 static DEVICE_ATTR_RO(path);
436 /* sysfs file that shows description text from the ACPI _STR method */
437 static ssize_t description_show(struct device *dev,
438 struct device_attribute *attr,
441 struct acpi_device *acpi_dev = to_acpi_device(dev);
444 if (acpi_dev->pnp.str_obj == NULL)
448 * The _STR object contains a Unicode identifier for a device.
449 * We need to convert to utf-8 so it can be displayed.
451 result = utf16s_to_utf8s(
452 (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
453 acpi_dev->pnp.str_obj->buffer.length,
454 UTF16_LITTLE_ENDIAN, buf,
457 buf[result++] = '\n';
461 static DEVICE_ATTR_RO(description);
464 sun_show(struct device *dev, struct device_attribute *attr,
467 struct acpi_device *acpi_dev = to_acpi_device(dev);
469 unsigned long long sun;
471 status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
472 if (ACPI_FAILURE(status))
475 return sprintf(buf, "%llu\n", sun);
477 static DEVICE_ATTR_RO(sun);
480 hrv_show(struct device *dev, struct device_attribute *attr,
483 struct acpi_device *acpi_dev = to_acpi_device(dev);
485 unsigned long long hrv;
487 status = acpi_evaluate_integer(acpi_dev->handle, "_HRV", NULL, &hrv);
488 if (ACPI_FAILURE(status))
491 return sprintf(buf, "%llu\n", hrv);
493 static DEVICE_ATTR_RO(hrv);
495 static ssize_t status_show(struct device *dev, struct device_attribute *attr,
498 struct acpi_device *acpi_dev = to_acpi_device(dev);
500 unsigned long long sta;
502 status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
503 if (ACPI_FAILURE(status))
506 return sprintf(buf, "%llu\n", sta);
508 static DEVICE_ATTR_RO(status);
511 * acpi_device_setup_files - Create sysfs attributes of an ACPI device.
512 * @dev: ACPI device object.
514 int acpi_device_setup_files(struct acpi_device *dev)
516 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
521 * Devices gotten from FADT don't have a "path" attribute
524 result = device_create_file(&dev->dev, &dev_attr_path);
529 if (!list_empty(&dev->pnp.ids)) {
530 result = device_create_file(&dev->dev, &dev_attr_hid);
534 result = device_create_file(&dev->dev, &dev_attr_modalias);
540 * If device has _STR, 'description' file is created
542 if (acpi_has_method(dev->handle, "_STR")) {
543 status = acpi_evaluate_object(dev->handle, "_STR",
545 if (ACPI_FAILURE(status))
546 buffer.pointer = NULL;
547 dev->pnp.str_obj = buffer.pointer;
548 result = device_create_file(&dev->dev, &dev_attr_description);
553 if (dev->pnp.type.bus_address)
554 result = device_create_file(&dev->dev, &dev_attr_adr);
555 if (acpi_device_uid(dev))
556 result = device_create_file(&dev->dev, &dev_attr_uid);
558 if (acpi_has_method(dev->handle, "_SUN")) {
559 result = device_create_file(&dev->dev, &dev_attr_sun);
564 if (acpi_has_method(dev->handle, "_HRV")) {
565 result = device_create_file(&dev->dev, &dev_attr_hrv);
570 if (acpi_has_method(dev->handle, "_STA")) {
571 result = device_create_file(&dev->dev, &dev_attr_status);
577 * If device has _EJ0, 'eject' file is created that is used to trigger
578 * hot-removal function from userland.
580 if (acpi_has_method(dev->handle, "_EJ0")) {
581 result = device_create_file(&dev->dev, &dev_attr_eject);
586 if (dev->flags.power_manageable) {
587 result = device_create_file(&dev->dev, &dev_attr_power_state);
591 if (dev->power.flags.power_resources)
592 result = device_create_file(&dev->dev,
593 &dev_attr_real_power_state);
596 acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data);
603 * acpi_device_remove_files - Remove sysfs attributes of an ACPI device.
604 * @dev: ACPI device object.
606 void acpi_device_remove_files(struct acpi_device *dev)
608 acpi_hide_nondev_subnodes(&dev->data);
610 if (dev->flags.power_manageable) {
611 device_remove_file(&dev->dev, &dev_attr_power_state);
612 if (dev->power.flags.power_resources)
613 device_remove_file(&dev->dev,
614 &dev_attr_real_power_state);
618 * If device has _STR, remove 'description' file
620 if (acpi_has_method(dev->handle, "_STR")) {
621 kfree(dev->pnp.str_obj);
622 device_remove_file(&dev->dev, &dev_attr_description);
625 * If device has _EJ0, remove 'eject' file.
627 if (acpi_has_method(dev->handle, "_EJ0"))
628 device_remove_file(&dev->dev, &dev_attr_eject);
630 if (acpi_has_method(dev->handle, "_SUN"))
631 device_remove_file(&dev->dev, &dev_attr_sun);
633 if (acpi_has_method(dev->handle, "_HRV"))
634 device_remove_file(&dev->dev, &dev_attr_hrv);
636 if (acpi_device_uid(dev))
637 device_remove_file(&dev->dev, &dev_attr_uid);
638 if (dev->pnp.type.bus_address)
639 device_remove_file(&dev->dev, &dev_attr_adr);
640 device_remove_file(&dev->dev, &dev_attr_modalias);
641 device_remove_file(&dev->dev, &dev_attr_hid);
642 if (acpi_has_method(dev->handle, "_STA"))
643 device_remove_file(&dev->dev, &dev_attr_status);
645 device_remove_file(&dev->dev, &dev_attr_path);