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0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * drivers/acpi/device_sysfs.c - ACPI device sysfs attributes and modalias.
0004  *
0005  * Copyright (C) 2015, Intel Corp.
0006  * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
0007  * Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
0008  *
0009  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
0010  *
0011  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
0012  */
0013 
0014 #include <linux/acpi.h>
0015 #include <linux/device.h>
0016 #include <linux/export.h>
0017 #include <linux/nls.h>
0018 
0019 #include "internal.h"
0020 
0021 static ssize_t acpi_object_path(acpi_handle handle, char *buf)
0022 {
0023     struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
0024     int result;
0025 
0026     result = acpi_get_name(handle, ACPI_FULL_PATHNAME, &path);
0027     if (result)
0028         return result;
0029 
0030     result = sprintf(buf, "%s\n", (char *)path.pointer);
0031     kfree(path.pointer);
0032     return result;
0033 }
0034 
0035 struct acpi_data_node_attr {
0036     struct attribute attr;
0037     ssize_t (*show)(struct acpi_data_node *, char *);
0038     ssize_t (*store)(struct acpi_data_node *, const char *, size_t count);
0039 };
0040 
0041 #define DATA_NODE_ATTR(_name)           \
0042     static struct acpi_data_node_attr data_node_##_name =   \
0043         __ATTR(_name, 0444, data_node_show_##_name, NULL)
0044 
0045 static ssize_t data_node_show_path(struct acpi_data_node *dn, char *buf)
0046 {
0047     return dn->handle ? acpi_object_path(dn->handle, buf) : 0;
0048 }
0049 
0050 DATA_NODE_ATTR(path);
0051 
0052 static struct attribute *acpi_data_node_default_attrs[] = {
0053     &data_node_path.attr,
0054     NULL
0055 };
0056 ATTRIBUTE_GROUPS(acpi_data_node_default);
0057 
0058 #define to_data_node(k) container_of(k, struct acpi_data_node, kobj)
0059 #define to_attr(a) container_of(a, struct acpi_data_node_attr, attr)
0060 
0061 static ssize_t acpi_data_node_attr_show(struct kobject *kobj,
0062                     struct attribute *attr, char *buf)
0063 {
0064     struct acpi_data_node *dn = to_data_node(kobj);
0065     struct acpi_data_node_attr *dn_attr = to_attr(attr);
0066 
0067     return dn_attr->show ? dn_attr->show(dn, buf) : -ENXIO;
0068 }
0069 
0070 static const struct sysfs_ops acpi_data_node_sysfs_ops = {
0071     .show   = acpi_data_node_attr_show,
0072 };
0073 
0074 static void acpi_data_node_release(struct kobject *kobj)
0075 {
0076     struct acpi_data_node *dn = to_data_node(kobj);
0077 
0078     complete(&dn->kobj_done);
0079 }
0080 
0081 static struct kobj_type acpi_data_node_ktype = {
0082     .sysfs_ops = &acpi_data_node_sysfs_ops,
0083     .default_groups = acpi_data_node_default_groups,
0084     .release = acpi_data_node_release,
0085 };
0086 
0087 static void acpi_expose_nondev_subnodes(struct kobject *kobj,
0088                     struct acpi_device_data *data)
0089 {
0090     struct list_head *list = &data->subnodes;
0091     struct acpi_data_node *dn;
0092 
0093     if (list_empty(list))
0094         return;
0095 
0096     list_for_each_entry(dn, list, sibling) {
0097         int ret;
0098 
0099         init_completion(&dn->kobj_done);
0100         ret = kobject_init_and_add(&dn->kobj, &acpi_data_node_ktype,
0101                        kobj, "%s", dn->name);
0102         if (!ret)
0103             acpi_expose_nondev_subnodes(&dn->kobj, &dn->data);
0104         else if (dn->handle)
0105             acpi_handle_err(dn->handle, "Failed to expose (%d)\n", ret);
0106     }
0107 }
0108 
0109 static void acpi_hide_nondev_subnodes(struct acpi_device_data *data)
0110 {
0111     struct list_head *list = &data->subnodes;
0112     struct acpi_data_node *dn;
0113 
0114     if (list_empty(list))
0115         return;
0116 
0117     list_for_each_entry_reverse(dn, list, sibling) {
0118         acpi_hide_nondev_subnodes(&dn->data);
0119         kobject_put(&dn->kobj);
0120     }
0121 }
0122 
0123 /**
0124  * create_pnp_modalias - Create hid/cid(s) string for modalias and uevent
0125  * @acpi_dev: ACPI device object.
0126  * @modalias: Buffer to print into.
0127  * @size: Size of the buffer.
0128  *
0129  * Creates hid/cid(s) string needed for modalias and uevent
0130  * e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
0131  * char *modalias: "acpi:IBM0001:ACPI0001"
0132  * Return: 0: no _HID and no _CID
0133  *         -EINVAL: output error
0134  *         -ENOMEM: output is truncated
0135  */
0136 static int create_pnp_modalias(struct acpi_device *acpi_dev, char *modalias,
0137                    int size)
0138 {
0139     int len;
0140     int count;
0141     struct acpi_hardware_id *id;
0142 
0143     /* Avoid unnecessarily loading modules for non present devices. */
0144     if (!acpi_device_is_present(acpi_dev))
0145         return 0;
0146 
0147     /*
0148      * Since we skip ACPI_DT_NAMESPACE_HID from the modalias below, 0 should
0149      * be returned if ACPI_DT_NAMESPACE_HID is the only ACPI/PNP ID in the
0150      * device's list.
0151      */
0152     count = 0;
0153     list_for_each_entry(id, &acpi_dev->pnp.ids, list)
0154         if (strcmp(id->id, ACPI_DT_NAMESPACE_HID))
0155             count++;
0156 
0157     if (!count)
0158         return 0;
0159 
0160     len = snprintf(modalias, size, "acpi:");
0161     if (len <= 0)
0162         return len;
0163 
0164     size -= len;
0165 
0166     list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
0167         if (!strcmp(id->id, ACPI_DT_NAMESPACE_HID))
0168             continue;
0169 
0170         count = snprintf(&modalias[len], size, "%s:", id->id);
0171         if (count < 0)
0172             return -EINVAL;
0173 
0174         if (count >= size)
0175             return -ENOMEM;
0176 
0177         len += count;
0178         size -= count;
0179     }
0180     modalias[len] = '\0';
0181     return len;
0182 }
0183 
0184 /**
0185  * create_of_modalias - Creates DT compatible string for modalias and uevent
0186  * @acpi_dev: ACPI device object.
0187  * @modalias: Buffer to print into.
0188  * @size: Size of the buffer.
0189  *
0190  * Expose DT compatible modalias as of:NnameTCcompatible.  This function should
0191  * only be called for devices having ACPI_DT_NAMESPACE_HID in their list of
0192  * ACPI/PNP IDs.
0193  */
0194 static int create_of_modalias(struct acpi_device *acpi_dev, char *modalias,
0195                   int size)
0196 {
0197     struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
0198     const union acpi_object *of_compatible, *obj;
0199     acpi_status status;
0200     int len, count;
0201     int i, nval;
0202     char *c;
0203 
0204     status = acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf);
0205     if (ACPI_FAILURE(status))
0206         return -ENODEV;
0207 
0208     /* DT strings are all in lower case */
0209     for (c = buf.pointer; *c != '\0'; c++)
0210         *c = tolower(*c);
0211 
0212     len = snprintf(modalias, size, "of:N%sT", (char *)buf.pointer);
0213     ACPI_FREE(buf.pointer);
0214 
0215     if (len <= 0)
0216         return len;
0217 
0218     of_compatible = acpi_dev->data.of_compatible;
0219     if (of_compatible->type == ACPI_TYPE_PACKAGE) {
0220         nval = of_compatible->package.count;
0221         obj = of_compatible->package.elements;
0222     } else { /* Must be ACPI_TYPE_STRING. */
0223         nval = 1;
0224         obj = of_compatible;
0225     }
0226     for (i = 0; i < nval; i++, obj++) {
0227         count = snprintf(&modalias[len], size, "C%s",
0228                  obj->string.pointer);
0229         if (count < 0)
0230             return -EINVAL;
0231 
0232         if (count >= size)
0233             return -ENOMEM;
0234 
0235         len += count;
0236         size -= count;
0237     }
0238     modalias[len] = '\0';
0239     return len;
0240 }
0241 
0242 int __acpi_device_uevent_modalias(struct acpi_device *adev,
0243                   struct kobj_uevent_env *env)
0244 {
0245     int len;
0246 
0247     if (!adev)
0248         return -ENODEV;
0249 
0250     if (list_empty(&adev->pnp.ids))
0251         return 0;
0252 
0253     if (add_uevent_var(env, "MODALIAS="))
0254         return -ENOMEM;
0255 
0256     if (adev->data.of_compatible)
0257         len = create_of_modalias(adev, &env->buf[env->buflen - 1],
0258                      sizeof(env->buf) - env->buflen);
0259     else
0260         len = create_pnp_modalias(adev, &env->buf[env->buflen - 1],
0261                       sizeof(env->buf) - env->buflen);
0262     if (len < 0)
0263         return len;
0264 
0265     env->buflen += len;
0266 
0267     return 0;
0268 }
0269 
0270 /**
0271  * acpi_device_uevent_modalias - uevent modalias for ACPI-enumerated devices.
0272  * @dev: Struct device to get ACPI device node.
0273  * @env: Environment variables of the kobject uevent.
0274  *
0275  * Create the uevent modalias field for ACPI-enumerated devices.
0276  *
0277  * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
0278  * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
0279  */
0280 int acpi_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
0281 {
0282     return __acpi_device_uevent_modalias(acpi_companion_match(dev), env);
0283 }
0284 EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
0285 
0286 static int __acpi_device_modalias(struct acpi_device *adev, char *buf, int size)
0287 {
0288     int len, count;
0289 
0290     if (!adev)
0291         return -ENODEV;
0292 
0293     if (list_empty(&adev->pnp.ids))
0294         return 0;
0295 
0296     len = create_pnp_modalias(adev, buf, size - 1);
0297     if (len < 0) {
0298         return len;
0299     } else if (len > 0) {
0300         buf[len++] = '\n';
0301         size -= len;
0302     }
0303     if (!adev->data.of_compatible)
0304         return len;
0305 
0306     count = create_of_modalias(adev, buf + len, size - 1);
0307     if (count < 0) {
0308         return count;
0309     } else if (count > 0) {
0310         len += count;
0311         buf[len++] = '\n';
0312     }
0313 
0314     return len;
0315 }
0316 
0317 /**
0318  * acpi_device_modalias - modalias sysfs attribute for ACPI-enumerated devices.
0319  * @dev: Struct device to get ACPI device node.
0320  * @buf: The buffer to save pnp_modalias and of_modalias.
0321  * @size: Size of buffer.
0322  *
0323  * Create the modalias sysfs attribute for ACPI-enumerated devices.
0324  *
0325  * Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
0326  * hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
0327  */
0328 int acpi_device_modalias(struct device *dev, char *buf, int size)
0329 {
0330     return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
0331 }
0332 EXPORT_SYMBOL_GPL(acpi_device_modalias);
0333 
0334 static ssize_t
0335 modalias_show(struct device *dev, struct device_attribute *attr, char *buf)
0336 {
0337     return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
0338 }
0339 static DEVICE_ATTR_RO(modalias);
0340 
0341 static ssize_t real_power_state_show(struct device *dev,
0342                      struct device_attribute *attr, char *buf)
0343 {
0344     struct acpi_device *adev = to_acpi_device(dev);
0345     int state;
0346     int ret;
0347 
0348     ret = acpi_device_get_power(adev, &state);
0349     if (ret)
0350         return ret;
0351 
0352     return sprintf(buf, "%s\n", acpi_power_state_string(state));
0353 }
0354 
0355 static DEVICE_ATTR_RO(real_power_state);
0356 
0357 static ssize_t power_state_show(struct device *dev,
0358                 struct device_attribute *attr, char *buf)
0359 {
0360     struct acpi_device *adev = to_acpi_device(dev);
0361 
0362     return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
0363 }
0364 
0365 static DEVICE_ATTR_RO(power_state);
0366 
0367 static ssize_t
0368 eject_store(struct device *d, struct device_attribute *attr,
0369         const char *buf, size_t count)
0370 {
0371     struct acpi_device *acpi_device = to_acpi_device(d);
0372     acpi_object_type not_used;
0373     acpi_status status;
0374 
0375     if (!count || buf[0] != '1')
0376         return -EINVAL;
0377 
0378     if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
0379         && !d->driver)
0380         return -ENODEV;
0381 
0382     status = acpi_get_type(acpi_device->handle, &not_used);
0383     if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
0384         return -ENODEV;
0385 
0386     acpi_dev_get(acpi_device);
0387     status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
0388     if (ACPI_SUCCESS(status))
0389         return count;
0390 
0391     acpi_dev_put(acpi_device);
0392     acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
0393               ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
0394     return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
0395 }
0396 
0397 static DEVICE_ATTR_WO(eject);
0398 
0399 static ssize_t
0400 hid_show(struct device *dev, struct device_attribute *attr, char *buf)
0401 {
0402     struct acpi_device *acpi_dev = to_acpi_device(dev);
0403 
0404     return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
0405 }
0406 static DEVICE_ATTR_RO(hid);
0407 
0408 static ssize_t uid_show(struct device *dev,
0409             struct device_attribute *attr, char *buf)
0410 {
0411     struct acpi_device *acpi_dev = to_acpi_device(dev);
0412 
0413     return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
0414 }
0415 static DEVICE_ATTR_RO(uid);
0416 
0417 static ssize_t adr_show(struct device *dev,
0418             struct device_attribute *attr, char *buf)
0419 {
0420     struct acpi_device *acpi_dev = to_acpi_device(dev);
0421 
0422     if (acpi_dev->pnp.bus_address > U32_MAX)
0423         return sprintf(buf, "0x%016llx\n", acpi_dev->pnp.bus_address);
0424     else
0425         return sprintf(buf, "0x%08llx\n", acpi_dev->pnp.bus_address);
0426 }
0427 static DEVICE_ATTR_RO(adr);
0428 
0429 static ssize_t path_show(struct device *dev,
0430              struct device_attribute *attr, char *buf)
0431 {
0432     struct acpi_device *acpi_dev = to_acpi_device(dev);
0433 
0434     return acpi_object_path(acpi_dev->handle, buf);
0435 }
0436 static DEVICE_ATTR_RO(path);
0437 
0438 /* sysfs file that shows description text from the ACPI _STR method */
0439 static ssize_t description_show(struct device *dev,
0440                 struct device_attribute *attr,
0441                 char *buf)
0442 {
0443     struct acpi_device *acpi_dev = to_acpi_device(dev);
0444     int result;
0445 
0446     if (acpi_dev->pnp.str_obj == NULL)
0447         return 0;
0448 
0449     /*
0450      * The _STR object contains a Unicode identifier for a device.
0451      * We need to convert to utf-8 so it can be displayed.
0452      */
0453     result = utf16s_to_utf8s(
0454         (wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
0455         acpi_dev->pnp.str_obj->buffer.length,
0456         UTF16_LITTLE_ENDIAN, buf,
0457         PAGE_SIZE - 1);
0458 
0459     buf[result++] = '\n';
0460 
0461     return result;
0462 }
0463 static DEVICE_ATTR_RO(description);
0464 
0465 static ssize_t
0466 sun_show(struct device *dev, struct device_attribute *attr,
0467      char *buf)
0468 {
0469     struct acpi_device *acpi_dev = to_acpi_device(dev);
0470     acpi_status status;
0471     unsigned long long sun;
0472 
0473     status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
0474     if (ACPI_FAILURE(status))
0475         return -EIO;
0476 
0477     return sprintf(buf, "%llu\n", sun);
0478 }
0479 static DEVICE_ATTR_RO(sun);
0480 
0481 static ssize_t
0482 hrv_show(struct device *dev, struct device_attribute *attr,
0483      char *buf)
0484 {
0485     struct acpi_device *acpi_dev = to_acpi_device(dev);
0486     acpi_status status;
0487     unsigned long long hrv;
0488 
0489     status = acpi_evaluate_integer(acpi_dev->handle, "_HRV", NULL, &hrv);
0490     if (ACPI_FAILURE(status))
0491         return -EIO;
0492 
0493     return sprintf(buf, "%llu\n", hrv);
0494 }
0495 static DEVICE_ATTR_RO(hrv);
0496 
0497 static ssize_t status_show(struct device *dev, struct device_attribute *attr,
0498                 char *buf)
0499 {
0500     struct acpi_device *acpi_dev = to_acpi_device(dev);
0501     acpi_status status;
0502     unsigned long long sta;
0503 
0504     status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
0505     if (ACPI_FAILURE(status))
0506         return -EIO;
0507 
0508     return sprintf(buf, "%llu\n", sta);
0509 }
0510 static DEVICE_ATTR_RO(status);
0511 
0512 /**
0513  * acpi_device_setup_files - Create sysfs attributes of an ACPI device.
0514  * @dev: ACPI device object.
0515  */
0516 int acpi_device_setup_files(struct acpi_device *dev)
0517 {
0518     struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
0519     acpi_status status;
0520     int result = 0;
0521 
0522     /*
0523      * Devices gotten from FADT don't have a "path" attribute
0524      */
0525     if (dev->handle) {
0526         result = device_create_file(&dev->dev, &dev_attr_path);
0527         if (result)
0528             goto end;
0529     }
0530 
0531     if (!list_empty(&dev->pnp.ids)) {
0532         result = device_create_file(&dev->dev, &dev_attr_hid);
0533         if (result)
0534             goto end;
0535 
0536         result = device_create_file(&dev->dev, &dev_attr_modalias);
0537         if (result)
0538             goto end;
0539     }
0540 
0541     /*
0542      * If device has _STR, 'description' file is created
0543      */
0544     if (acpi_has_method(dev->handle, "_STR")) {
0545         status = acpi_evaluate_object(dev->handle, "_STR",
0546                     NULL, &buffer);
0547         if (ACPI_FAILURE(status))
0548             buffer.pointer = NULL;
0549         dev->pnp.str_obj = buffer.pointer;
0550         result = device_create_file(&dev->dev, &dev_attr_description);
0551         if (result)
0552             goto end;
0553     }
0554 
0555     if (dev->pnp.type.bus_address)
0556         result = device_create_file(&dev->dev, &dev_attr_adr);
0557     if (dev->pnp.unique_id)
0558         result = device_create_file(&dev->dev, &dev_attr_uid);
0559 
0560     if (acpi_has_method(dev->handle, "_SUN")) {
0561         result = device_create_file(&dev->dev, &dev_attr_sun);
0562         if (result)
0563             goto end;
0564     }
0565 
0566     if (acpi_has_method(dev->handle, "_HRV")) {
0567         result = device_create_file(&dev->dev, &dev_attr_hrv);
0568         if (result)
0569             goto end;
0570     }
0571 
0572     if (acpi_has_method(dev->handle, "_STA")) {
0573         result = device_create_file(&dev->dev, &dev_attr_status);
0574         if (result)
0575             goto end;
0576     }
0577 
0578     /*
0579      * If device has _EJ0, 'eject' file is created that is used to trigger
0580      * hot-removal function from userland.
0581      */
0582     if (acpi_has_method(dev->handle, "_EJ0")) {
0583         result = device_create_file(&dev->dev, &dev_attr_eject);
0584         if (result)
0585             return result;
0586     }
0587 
0588     if (dev->flags.power_manageable) {
0589         result = device_create_file(&dev->dev, &dev_attr_power_state);
0590         if (result)
0591             return result;
0592 
0593         if (dev->power.flags.power_resources)
0594             result = device_create_file(&dev->dev,
0595                             &dev_attr_real_power_state);
0596     }
0597 
0598     acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data);
0599 
0600 end:
0601     return result;
0602 }
0603 
0604 /**
0605  * acpi_device_remove_files - Remove sysfs attributes of an ACPI device.
0606  * @dev: ACPI device object.
0607  */
0608 void acpi_device_remove_files(struct acpi_device *dev)
0609 {
0610     acpi_hide_nondev_subnodes(&dev->data);
0611 
0612     if (dev->flags.power_manageable) {
0613         device_remove_file(&dev->dev, &dev_attr_power_state);
0614         if (dev->power.flags.power_resources)
0615             device_remove_file(&dev->dev,
0616                        &dev_attr_real_power_state);
0617     }
0618 
0619     /*
0620      * If device has _STR, remove 'description' file
0621      */
0622     if (acpi_has_method(dev->handle, "_STR")) {
0623         kfree(dev->pnp.str_obj);
0624         device_remove_file(&dev->dev, &dev_attr_description);
0625     }
0626     /*
0627      * If device has _EJ0, remove 'eject' file.
0628      */
0629     if (acpi_has_method(dev->handle, "_EJ0"))
0630         device_remove_file(&dev->dev, &dev_attr_eject);
0631 
0632     if (acpi_has_method(dev->handle, "_SUN"))
0633         device_remove_file(&dev->dev, &dev_attr_sun);
0634 
0635     if (acpi_has_method(dev->handle, "_HRV"))
0636         device_remove_file(&dev->dev, &dev_attr_hrv);
0637 
0638     if (dev->pnp.unique_id)
0639         device_remove_file(&dev->dev, &dev_attr_uid);
0640     if (dev->pnp.type.bus_address)
0641         device_remove_file(&dev->dev, &dev_attr_adr);
0642     device_remove_file(&dev->dev, &dev_attr_modalias);
0643     device_remove_file(&dev->dev, &dev_attr_hid);
0644     if (acpi_has_method(dev->handle, "_STA"))
0645         device_remove_file(&dev->dev, &dev_attr_status);
0646     if (dev->handle)
0647         device_remove_file(&dev->dev, &dev_attr_path);
0648 }
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