2 * drivers/acpi/device_sysfs.c - ACPI device sysfs attributes and modalias.
4 * Copyright (C) 2015, Intel Corp.
8 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as published
12 * by the Free Software Foundation.
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
19 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
22 #include <linux/acpi.h>
23 #include <linux/device.h>
24 #include <linux/export.h>
25 #include <linux/nls.h>
29 static ssize_t acpi_object_path(acpi_handle handle, char *buf)
31 struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
34 result = acpi_get_name(handle, ACPI_FULL_PATHNAME, &path);
38 result = sprintf(buf, "%s\n", (char *)path.pointer);
43 struct acpi_data_node_attr {
44 struct attribute attr;
45 ssize_t (*show)(struct acpi_data_node *, char *);
46 ssize_t (*store)(struct acpi_data_node *, const char *, size_t count);
49 #define DATA_NODE_ATTR(_name) \
50 static struct acpi_data_node_attr data_node_##_name = \
51 __ATTR(_name, 0444, data_node_show_##_name, NULL)
53 static ssize_t data_node_show_path(struct acpi_data_node *dn, char *buf)
55 return dn->handle ? acpi_object_path(dn->handle, buf) : 0;
60 static struct attribute *acpi_data_node_default_attrs[] = {
65 #define to_data_node(k) container_of(k, struct acpi_data_node, kobj)
66 #define to_attr(a) container_of(a, struct acpi_data_node_attr, attr)
68 static ssize_t acpi_data_node_attr_show(struct kobject *kobj,
69 struct attribute *attr, char *buf)
71 struct acpi_data_node *dn = to_data_node(kobj);
72 struct acpi_data_node_attr *dn_attr = to_attr(attr);
74 return dn_attr->show ? dn_attr->show(dn, buf) : -ENXIO;
77 static const struct sysfs_ops acpi_data_node_sysfs_ops = {
78 .show = acpi_data_node_attr_show,
81 static void acpi_data_node_release(struct kobject *kobj)
83 struct acpi_data_node *dn = to_data_node(kobj);
84 complete(&dn->kobj_done);
87 static struct kobj_type acpi_data_node_ktype = {
88 .sysfs_ops = &acpi_data_node_sysfs_ops,
89 .default_attrs = acpi_data_node_default_attrs,
90 .release = acpi_data_node_release,
93 static void acpi_expose_nondev_subnodes(struct kobject *kobj,
94 struct acpi_device_data *data)
96 struct list_head *list = &data->subnodes;
97 struct acpi_data_node *dn;
102 list_for_each_entry(dn, list, sibling) {
105 init_completion(&dn->kobj_done);
106 ret = kobject_init_and_add(&dn->kobj, &acpi_data_node_ktype,
107 kobj, "%s", dn->name);
109 acpi_expose_nondev_subnodes(&dn->kobj, &dn->data);
111 acpi_handle_err(dn->handle, "Failed to expose (%d)\n", ret);
115 static void acpi_hide_nondev_subnodes(struct acpi_device_data *data)
117 struct list_head *list = &data->subnodes;
118 struct acpi_data_node *dn;
120 if (list_empty(list))
123 list_for_each_entry_reverse(dn, list, sibling) {
124 acpi_hide_nondev_subnodes(&dn->data);
125 kobject_put(&dn->kobj);
130 * create_pnp_modalias - Create hid/cid(s) string for modalias and uevent
131 * @acpi_dev: ACPI device object.
132 * @modalias: Buffer to print into.
133 * @size: Size of the buffer.
135 * Creates hid/cid(s) string needed for modalias and uevent
136 * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
137 * char *modalias: "acpi:IBM0001:ACPI0001"
138 * Return: 0: no _HID and no _CID
139 * -EINVAL: output error
140 * -ENOMEM: output is truncated
142 static int create_pnp_modalias(struct acpi_device *acpi_dev, char *modalias,
147 struct acpi_hardware_id *id;
149 /* Avoid unnecessarily loading modules for non present devices. */
150 if (!acpi_device_is_present(acpi_dev))
154 * Since we skip ACPI_DT_NAMESPACE_HID from the modalias below, 0 should
155 * be returned if ACPI_DT_NAMESPACE_HID is the only ACPI/PNP ID in the
159 list_for_each_entry(id, &acpi_dev->pnp.ids, list)
160 if (strcmp(id->id, ACPI_DT_NAMESPACE_HID))
166 len = snprintf(modalias, size, "acpi:");
172 list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
173 if (!strcmp(id->id, ACPI_DT_NAMESPACE_HID))
176 count = snprintf(&modalias[len], size, "%s:", id->id);
186 modalias[len] = '\0';
191 * create_of_modalias - Creates DT compatible string for modalias and uevent
192 * @acpi_dev: ACPI device object.
193 * @modalias: Buffer to print into.
194 * @size: Size of the buffer.
196 * Expose DT compatible modalias as of:NnameTCcompatible. This function should
197 * only be called for devices having ACPI_DT_NAMESPACE_HID in their list of
200 static int create_of_modalias(struct acpi_device *acpi_dev, char *modalias,
203 struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
204 const union acpi_object *of_compatible, *obj;
210 status = acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf);
211 if (ACPI_FAILURE(status))
214 /* DT strings are all in lower case */
215 for (c = buf.pointer; *c != '\0'; c++)
218 len = snprintf(modalias, size, "of:N%sT", (char *)buf.pointer);
219 ACPI_FREE(buf.pointer);
224 of_compatible = acpi_dev->data.of_compatible;
225 if (of_compatible->type == ACPI_TYPE_PACKAGE) {
226 nval = of_compatible->package.count;
227 obj = of_compatible->package.elements;
228 } else { /* Must be ACPI_TYPE_STRING. */
232 for (i = 0; i < nval; i++, obj++) {
233 count = snprintf(&modalias[len], size, "C%s",
234 obj->string.pointer);
244 modalias[len] = '\0';
248 int __acpi_device_uevent_modalias(struct acpi_device *adev,
249 struct kobj_uevent_env *env)
256 if (list_empty(&adev->pnp.ids))
259 if (add_uevent_var(env, "MODALIAS="))
262 len = create_pnp_modalias(adev, &env->buf[env->buflen - 1],
263 sizeof(env->buf) - env->buflen);
268 if (!adev->data.of_compatible)
271 if (len > 0 && add_uevent_var(env, "MODALIAS="))
274 len = create_of_modalias(adev, &env->buf[env->buflen - 1],
275 sizeof(env->buf) - env->buflen);
285 * acpi_device_uevent_modalias - uevent modalias for ACPI-enumerated devices.
287 * Create the uevent modalias field for ACPI-enumerated devices.
289 * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
290 * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
292 int acpi_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
294 return __acpi_device_uevent_modalias(acpi_companion_match(dev), env);
296 EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
298 static int __acpi_device_modalias(struct acpi_device *adev, char *buf, int size)
305 if (list_empty(&adev->pnp.ids))
308 len = create_pnp_modalias(adev, buf, size - 1);
311 } else if (len > 0) {
315 if (!adev->data.of_compatible)
318 count = create_of_modalias(adev, buf + len, size - 1);
321 } else if (count > 0) {
330 * acpi_device_modalias - modalias sysfs attribute for ACPI-enumerated devices.
332 * Create the modalias sysfs attribute for ACPI-enumerated devices.
334 * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
335 * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
337 int acpi_device_modalias(struct device *dev, char *buf, int size)
339 return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
341 EXPORT_SYMBOL_GPL(acpi_device_modalias);
344 acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
346 return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
348 static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
350 static ssize_t real_power_state_show(struct device *dev,
351 struct device_attribute *attr, char *buf)
353 struct acpi_device *adev = to_acpi_device(dev);
357 ret = acpi_device_get_power(adev, &state);
361 return sprintf(buf, "%s\n", acpi_power_state_string(state));
364 static DEVICE_ATTR_RO(real_power_state);
366 static ssize_t power_state_show(struct device *dev,
367 struct device_attribute *attr, char *buf)
369 struct acpi_device *adev = to_acpi_device(dev);
371 return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
374 static DEVICE_ATTR_RO(power_state);
377 acpi_eject_store(struct device *d, struct device_attribute *attr,
378 const char *buf, size_t count)
380 struct acpi_device *acpi_device = to_acpi_device(d);
381 acpi_object_type not_used;
384 if (!count || buf[0] != '1')
387 if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
388 && !acpi_device->driver)
391 status = acpi_get_type(acpi_device->handle, ¬_used);
392 if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
395 get_device(&acpi_device->dev);
396 status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
397 if (ACPI_SUCCESS(status))
400 put_device(&acpi_device->dev);
401 acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
402 ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
403 return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
406 static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
409 acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf)
411 struct acpi_device *acpi_dev = to_acpi_device(dev);
413 return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
415 static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
417 static ssize_t acpi_device_uid_show(struct device *dev,
418 struct device_attribute *attr, char *buf)
420 struct acpi_device *acpi_dev = to_acpi_device(dev);
422 return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
424 static DEVICE_ATTR(uid, 0444, acpi_device_uid_show, NULL);
426 static ssize_t acpi_device_adr_show(struct device *dev,
427 struct device_attribute *attr, char *buf)
429 struct acpi_device *acpi_dev = to_acpi_device(dev);
431 return sprintf(buf, "0x%08x\n",
432 (unsigned int)(acpi_dev->pnp.bus_address));
434 static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);
436 static ssize_t acpi_device_path_show(struct device *dev,
437 struct device_attribute *attr, char *buf)
439 struct acpi_device *acpi_dev = to_acpi_device(dev);
441 return acpi_object_path(acpi_dev->handle, buf);
443 static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
445 /* sysfs file that shows description text from the ACPI _STR method */
446 static ssize_t description_show(struct device *dev,
447 struct device_attribute *attr,
449 struct acpi_device *acpi_dev = to_acpi_device(dev);
452 if (acpi_dev->pnp.str_obj == NULL)
456 * The _STR object contains a Unicode identifier for a device.
457 * We need to convert to utf-8 so it can be displayed.
459 result = utf16s_to_utf8s(
460 (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
461 acpi_dev->pnp.str_obj->buffer.length,
462 UTF16_LITTLE_ENDIAN, buf,
465 buf[result++] = '\n';
469 static DEVICE_ATTR_RO(description);
472 acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
474 struct acpi_device *acpi_dev = to_acpi_device(dev);
476 unsigned long long sun;
478 status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
479 if (ACPI_FAILURE(status))
482 return sprintf(buf, "%llu\n", sun);
484 static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
487 acpi_device_hrv_show(struct device *dev, struct device_attribute *attr,
489 struct acpi_device *acpi_dev = to_acpi_device(dev);
491 unsigned long long hrv;
493 status = acpi_evaluate_integer(acpi_dev->handle, "_HRV", NULL, &hrv);
494 if (ACPI_FAILURE(status))
497 return sprintf(buf, "%llu\n", hrv);
499 static DEVICE_ATTR(hrv, 0444, acpi_device_hrv_show, NULL);
501 static ssize_t status_show(struct device *dev, struct device_attribute *attr,
503 struct acpi_device *acpi_dev = to_acpi_device(dev);
505 unsigned long long sta;
507 status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
508 if (ACPI_FAILURE(status))
511 return sprintf(buf, "%llu\n", sta);
513 static DEVICE_ATTR_RO(status);
516 * acpi_device_setup_files - Create sysfs attributes of an ACPI device.
517 * @dev: ACPI device object.
519 int acpi_device_setup_files(struct acpi_device *dev)
521 struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
526 * Devices gotten from FADT don't have a "path" attribute
529 result = device_create_file(&dev->dev, &dev_attr_path);
534 if (!list_empty(&dev->pnp.ids)) {
535 result = device_create_file(&dev->dev, &dev_attr_hid);
539 result = device_create_file(&dev->dev, &dev_attr_modalias);
545 * If device has _STR, 'description' file is created
547 if (acpi_has_method(dev->handle, "_STR")) {
548 status = acpi_evaluate_object(dev->handle, "_STR",
550 if (ACPI_FAILURE(status))
551 buffer.pointer = NULL;
552 dev->pnp.str_obj = buffer.pointer;
553 result = device_create_file(&dev->dev, &dev_attr_description);
558 if (dev->pnp.type.bus_address)
559 result = device_create_file(&dev->dev, &dev_attr_adr);
560 if (dev->pnp.unique_id)
561 result = device_create_file(&dev->dev, &dev_attr_uid);
563 if (acpi_has_method(dev->handle, "_SUN")) {
564 result = device_create_file(&dev->dev, &dev_attr_sun);
569 if (acpi_has_method(dev->handle, "_HRV")) {
570 result = device_create_file(&dev->dev, &dev_attr_hrv);
575 if (acpi_has_method(dev->handle, "_STA")) {
576 result = device_create_file(&dev->dev, &dev_attr_status);
582 * If device has _EJ0, 'eject' file is created that is used to trigger
583 * hot-removal function from userland.
585 if (acpi_has_method(dev->handle, "_EJ0")) {
586 result = device_create_file(&dev->dev, &dev_attr_eject);
591 if (dev->flags.power_manageable) {
592 result = device_create_file(&dev->dev, &dev_attr_power_state);
596 if (dev->power.flags.power_resources)
597 result = device_create_file(&dev->dev,
598 &dev_attr_real_power_state);
601 acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data);
608 * acpi_device_remove_files - Remove sysfs attributes of an ACPI device.
609 * @dev: ACPI device object.
611 void acpi_device_remove_files(struct acpi_device *dev)
613 acpi_hide_nondev_subnodes(&dev->data);
615 if (dev->flags.power_manageable) {
616 device_remove_file(&dev->dev, &dev_attr_power_state);
617 if (dev->power.flags.power_resources)
618 device_remove_file(&dev->dev,
619 &dev_attr_real_power_state);
623 * If device has _STR, remove 'description' file
625 if (acpi_has_method(dev->handle, "_STR")) {
626 kfree(dev->pnp.str_obj);
627 device_remove_file(&dev->dev, &dev_attr_description);
630 * If device has _EJ0, remove 'eject' file.
632 if (acpi_has_method(dev->handle, "_EJ0"))
633 device_remove_file(&dev->dev, &dev_attr_eject);
635 if (acpi_has_method(dev->handle, "_SUN"))
636 device_remove_file(&dev->dev, &dev_attr_sun);
638 if (acpi_has_method(dev->handle, "_HRV"))
639 device_remove_file(&dev->dev, &dev_attr_hrv);
641 if (dev->pnp.unique_id)
642 device_remove_file(&dev->dev, &dev_attr_uid);
643 if (dev->pnp.type.bus_address)
644 device_remove_file(&dev->dev, &dev_attr_adr);
645 device_remove_file(&dev->dev, &dev_attr_modalias);
646 device_remove_file(&dev->dev, &dev_attr_hid);
647 if (acpi_has_method(dev->handle, "_STA"))
648 device_remove_file(&dev->dev, &dev_attr_status);
650 device_remove_file(&dev->dev, &dev_attr_path);