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1// SPDX-License-Identifier: GPL-2.0-only2/*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 NULL55};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 uevent125 * @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 uevent130 * 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 _CID133 * -EINVAL: output error134 * -ENOMEM: output is truncated135 */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 should149 * be returned if ACPI_DT_NAMESPACE_HID is the only ACPI/PNP ID in the150 * 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 uevent184 * @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 should189 * only be called for devices having ACPI_DT_NAMESPACE_HID in their list of190 * 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 else258 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 with276 * 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 with324 * 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_t333modalias_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_t366eject_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_t398hid_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 else423 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_t474sun_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_t490hrv_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 NULL534};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" attribute540 */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 trigger567 * 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 else591 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 NULL602};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}621