- 根目录:
- drivers
- acpi
- device_sysfs.c
/*
* drivers/acpi/device_sysfs.c - ACPI device sysfs attributes and modalias.
*
* Copyright (C) 2015, Intel Corp.
* Author: Mika Westerberg <mika.westerberg@linux.intel.com>
* Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
*/
#include <linux/acpi.h>
#include <linux/device.h>
#include <linux/export.h>
#include <linux/nls.h>
#include "internal.h"
static ssize_t acpi_object_path(acpi_handle handle, char *buf)
{
struct acpi_buffer path = {ACPI_ALLOCATE_BUFFER, NULL};
int result;
result = acpi_get_name(handle, ACPI_FULL_PATHNAME, &path);
if (result)
return result;
result = sprintf(buf, "%s\n", (char*)path.pointer);
kfree(path.pointer);
return result;
}
struct acpi_data_node_attr {
struct attribute attr;
ssize_t (*show)(struct acpi_data_node *, char *);
ssize_t (*store)(struct acpi_data_node *, const char *, size_t count);
};
#define DATA_NODE_ATTR(_name) \
static struct acpi_data_node_attr data_node_##_name = \
__ATTR(_name, 0444, data_node_show_##_name, NULL)
static ssize_t data_node_show_path(struct acpi_data_node *dn, char *buf)
{
return acpi_object_path(dn->handle, buf);
}
DATA_NODE_ATTR(path);
static struct attribute *acpi_data_node_default_attrs[] = {
&data_node_path.attr,
NULL
};
#define to_data_node(k) container_of(k, struct acpi_data_node, kobj)
#define to_attr(a) container_of(a, struct acpi_data_node_attr, attr)
static ssize_t acpi_data_node_attr_show(struct kobject *kobj,
struct attribute *attr, char *buf)
{
struct acpi_data_node *dn = to_data_node(kobj);
struct acpi_data_node_attr *dn_attr = to_attr(attr);
return dn_attr->show ? dn_attr->show(dn, buf) : -ENXIO;
}
static const struct sysfs_ops acpi_data_node_sysfs_ops = {
.show = acpi_data_node_attr_show,
};
static void acpi_data_node_release(struct kobject *kobj)
{
struct acpi_data_node *dn = to_data_node(kobj);
complete(&dn->kobj_done);
}
static struct kobj_type acpi_data_node_ktype = {
.sysfs_ops = &acpi_data_node_sysfs_ops,
.default_attrs = acpi_data_node_default_attrs,
.release = acpi_data_node_release,
};
static void acpi_expose_nondev_subnodes(struct kobject *kobj,
struct acpi_device_data *data)
{
struct list_head *list = &data->subnodes;
struct acpi_data_node *dn;
if (list_empty(list))
return;
list_for_each_entry(dn, list, sibling) {
int ret;
init_completion(&dn->kobj_done);
ret = kobject_init_and_add(&dn->kobj, &acpi_data_node_ktype,
kobj, "%s", dn->name);
if (ret)
acpi_handle_err(dn->handle, "Failed to expose (%d)\n", ret);
else
acpi_expose_nondev_subnodes(&dn->kobj, &dn->data);
}
}
static void acpi_hide_nondev_subnodes(struct acpi_device_data *data)
{
struct list_head *list = &data->subnodes;
struct acpi_data_node *dn;
if (list_empty(list))
return;
list_for_each_entry_reverse(dn, list, sibling) {
acpi_hide_nondev_subnodes(&dn->data);
kobject_put(&dn->kobj);
}
}
/**
* create_pnp_modalias - Create hid/cid(s) string for modalias and uevent
* @acpi_dev: ACPI device object.
* @modalias: Buffer to print into.
* @size: Size of the buffer.
*
* Creates hid/cid(s) string needed for modalias and uevent
* e.g. on a device with hid:IBM0001 and cid:ACPI0001 you get:
* char *modalias: "acpi:IBM0001:ACPI0001"
* Return: 0: no _HID and no _CID
* -EINVAL: output error
* -ENOMEM: output is truncated
*/
static int create_pnp_modalias(struct acpi_device *acpi_dev, char *modalias,
int size)
{
int len;
int count;
struct acpi_hardware_id *id;
/*
* Since we skip ACPI_DT_NAMESPACE_HID from the modalias below, 0 should
* be returned if ACPI_DT_NAMESPACE_HID is the only ACPI/PNP ID in the
* device's list.
*/
count = 0;
list_for_each_entry(id, &acpi_dev->pnp.ids, list)
if (strcmp(id->id, ACPI_DT_NAMESPACE_HID))
count++;
if (!count)
return 0;
len = snprintf(modalias, size, "acpi:");
if (len <= 0)
return len;
size -= len;
list_for_each_entry(id, &acpi_dev->pnp.ids, list) {
if (!strcmp(id->id, ACPI_DT_NAMESPACE_HID))
continue;
count = snprintf(&modalias[len], size, "%s:", id->id);
if (count < 0)
return -EINVAL;
if (count >= size)
return -ENOMEM;
len += count;
size -= count;
}
modalias[len] = '\0';
return len;
}
/**
* create_of_modalias - Creates DT compatible string for modalias and uevent
* @acpi_dev: ACPI device object.
* @modalias: Buffer to print into.
* @size: Size of the buffer.
*
* Expose DT compatible modalias as of:NnameTCcompatible. This function should
* only be called for devices having ACPI_DT_NAMESPACE_HID in their list of
* ACPI/PNP IDs.
*/
static int create_of_modalias(struct acpi_device *acpi_dev, char *modalias,
int size)
{
struct acpi_buffer buf = { ACPI_ALLOCATE_BUFFER };
const union acpi_object *of_compatible, *obj;
int len, count;
int i, nval;
char *c;
acpi_get_name(acpi_dev->handle, ACPI_SINGLE_NAME, &buf);
/* DT strings are all in lower case */
for (c = buf.pointer; *c != '\0'; c++)
*c = tolower(*c);
len = snprintf(modalias, size, "of:N%sT", (char *)buf.pointer);
ACPI_FREE(buf.pointer);
if (len <= 0)
return len;
of_compatible = acpi_dev->data.of_compatible;
if (of_compatible->type == ACPI_TYPE_PACKAGE) {
nval = of_compatible->package.count;
obj = of_compatible->package.elements;
} else { /* Must be ACPI_TYPE_STRING. */
nval = 1;
obj = of_compatible;
}
for (i = 0; i < nval; i++, obj++) {
count = snprintf(&modalias[len], size, "C%s",
obj->string.pointer);
if (count < 0)
return -EINVAL;
if (count >= size)
return -ENOMEM;
len += count;
size -= count;
}
modalias[len] = '\0';
return len;
}
int __acpi_device_uevent_modalias(struct acpi_device *adev,
struct kobj_uevent_env *env)
{
int len;
if (!adev)
return -ENODEV;
if (list_empty(&adev->pnp.ids))
return 0;
if (add_uevent_var(env, "MODALIAS="))
return -ENOMEM;
len = create_pnp_modalias(adev, &env->buf[env->buflen - 1],
sizeof(env->buf) - env->buflen);
if (len < 0)
return len;
env->buflen += len;
if (!adev->data.of_compatible)
return 0;
if (len > 0 && add_uevent_var(env, "MODALIAS="))
return -ENOMEM;
len = create_of_modalias(adev, &env->buf[env->buflen - 1],
sizeof(env->buf) - env->buflen);
if (len < 0)
return len;
env->buflen += len;
return 0;
}
/**
* acpi_device_uevent_modalias - uevent modalias for ACPI-enumerated devices.
*
* Create the uevent modalias field for ACPI-enumerated devices.
*
* Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
* hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
*/
int acpi_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
{
return __acpi_device_uevent_modalias(acpi_companion_match(dev), env);
}
EXPORT_SYMBOL_GPL(acpi_device_uevent_modalias);
static int __acpi_device_modalias(struct acpi_device *adev, char *buf, int size)
{
int len, count;
if (!adev)
return -ENODEV;
if (list_empty(&adev->pnp.ids))
return 0;
len = create_pnp_modalias(adev, buf, size - 1);
if (len < 0) {
return len;
} else if (len > 0) {
buf[len++] = '\n';
size -= len;
}
if (!adev->data.of_compatible)
return len;
count = create_of_modalias(adev, buf + len, size - 1);
if (count < 0) {
return count;
} else if (count > 0) {
len += count;
buf[len++] = '\n';
}
return len;
}
/**
* acpi_device_modalias - modalias sysfs attribute for ACPI-enumerated devices.
*
* Create the modalias sysfs attribute for ACPI-enumerated devices.
*
* Because other buses do not support ACPI HIDs & CIDs, e.g. for a device with
* hid:IBM0001 and cid:ACPI0001 you get: "acpi:IBM0001:ACPI0001".
*/
int acpi_device_modalias(struct device *dev, char *buf, int size)
{
return __acpi_device_modalias(acpi_companion_match(dev), buf, size);
}
EXPORT_SYMBOL_GPL(acpi_device_modalias);
static ssize_t
acpi_device_modalias_show(struct device *dev, struct device_attribute *attr, char *buf) {
return __acpi_device_modalias(to_acpi_device(dev), buf, 1024);
}
static DEVICE_ATTR(modalias, 0444, acpi_device_modalias_show, NULL);
static ssize_t real_power_state_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct acpi_device *adev = to_acpi_device(dev);
int state;
int ret;
ret = acpi_device_get_power(adev, &state);
if (ret)
return ret;
return sprintf(buf, "%s\n", acpi_power_state_string(state));
}
static DEVICE_ATTR(real_power_state, 0444, real_power_state_show, NULL);
static ssize_t power_state_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct acpi_device *adev = to_acpi_device(dev);
return sprintf(buf, "%s\n", acpi_power_state_string(adev->power.state));
}
static DEVICE_ATTR(power_state, 0444, power_state_show, NULL);
static ssize_t
acpi_eject_store(struct device *d, struct device_attribute *attr,
const char *buf, size_t count)
{
struct acpi_device *acpi_device = to_acpi_device(d);
acpi_object_type not_used;
acpi_status status;
if (!count || buf[0] != '1')
return -EINVAL;
if ((!acpi_device->handler || !acpi_device->handler->hotplug.enabled)
&& !acpi_device->driver)
return -ENODEV;
status = acpi_get_type(acpi_device->handle, ¬_used);
if (ACPI_FAILURE(status) || !acpi_device->flags.ejectable)
return -ENODEV;
get_device(&acpi_device->dev);
status = acpi_hotplug_schedule(acpi_device, ACPI_OST_EC_OSPM_EJECT);
if (ACPI_SUCCESS(status))
return count;
put_device(&acpi_device->dev);
acpi_evaluate_ost(acpi_device->handle, ACPI_OST_EC_OSPM_EJECT,
ACPI_OST_SC_NON_SPECIFIC_FAILURE, NULL);
return status == AE_NO_MEMORY ? -ENOMEM : -EAGAIN;
}
static DEVICE_ATTR(eject, 0200, NULL, acpi_eject_store);
static ssize_t
acpi_device_hid_show(struct device *dev, struct device_attribute *attr, char *buf) {
struct acpi_device *acpi_dev = to_acpi_device(dev);
return sprintf(buf, "%s\n", acpi_device_hid(acpi_dev));
}
static DEVICE_ATTR(hid, 0444, acpi_device_hid_show, NULL);
static ssize_t acpi_device_uid_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct acpi_device *acpi_dev = to_acpi_device(dev);
return sprintf(buf, "%s\n", acpi_dev->pnp.unique_id);
}
static DEVICE_ATTR(uid, 0444, acpi_device_uid_show, NULL);
static ssize_t acpi_device_adr_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct acpi_device *acpi_dev = to_acpi_device(dev);
return sprintf(buf, "0x%08x\n",
(unsigned int)(acpi_dev->pnp.bus_address));
}
static DEVICE_ATTR(adr, 0444, acpi_device_adr_show, NULL);
static ssize_t acpi_device_path_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct acpi_device *acpi_dev = to_acpi_device(dev);
return acpi_object_path(acpi_dev->handle, buf);
}
static DEVICE_ATTR(path, 0444, acpi_device_path_show, NULL);
/* sysfs file that shows description text from the ACPI _STR method */
static ssize_t description_show(struct device *dev,
struct device_attribute *attr,
char *buf) {
struct acpi_device *acpi_dev = to_acpi_device(dev);
int result;
if (acpi_dev->pnp.str_obj == NULL)
return 0;
/*
* The _STR object contains a Unicode identifier for a device.
* We need to convert to utf-8 so it can be displayed.
*/
result = utf16s_to_utf8s(
(wchar_t *)acpi_dev->pnp.str_obj->buffer.pointer,
acpi_dev->pnp.str_obj->buffer.length,
UTF16_LITTLE_ENDIAN, buf,
PAGE_SIZE);
buf[result++] = '\n';
return result;
}
static DEVICE_ATTR(description, 0444, description_show, NULL);
static ssize_t
acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
char *buf) {
struct acpi_device *acpi_dev = to_acpi_device(dev);
acpi_status status;
unsigned long long sun;
status = acpi_evaluate_integer(acpi_dev->handle, "_SUN", NULL, &sun);
if (ACPI_FAILURE(status))
return -ENODEV;
return sprintf(buf, "%llu\n", sun);
}
static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
static ssize_t status_show(struct device *dev, struct device_attribute *attr,
char *buf) {
struct acpi_device *acpi_dev = to_acpi_device(dev);
acpi_status status;
unsigned long long sta;
status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
if (ACPI_FAILURE(status))
return -ENODEV;
return sprintf(buf, "%llu\n", sta);
}
static DEVICE_ATTR_RO(status);
/**
* acpi_device_setup_files - Create sysfs attributes of an ACPI device.
* @dev: ACPI device object.
*/
int acpi_device_setup_files(struct acpi_device *dev)
{
struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
acpi_status status;
int result = 0;
/*
* Devices gotten from FADT don't have a "path" attribute
*/
if (dev->handle) {
result = device_create_file(&dev->dev, &dev_attr_path);
if (result)
goto end;
}
if (!list_empty(&dev->pnp.ids)) {
result = device_create_file(&dev->dev, &dev_attr_hid);
if (result)
goto end;
result = device_create_file(&dev->dev, &dev_attr_modalias);
if (result)
goto end;
}
/*
* If device has _STR, 'description' file is created
*/
if (acpi_has_method(dev->handle, "_STR")) {
status = acpi_evaluate_object(dev->handle, "_STR",
NULL, &buffer);
if (ACPI_FAILURE(status))
buffer.pointer = NULL;
dev->pnp.str_obj = buffer.pointer;
result = device_create_file(&dev->dev, &dev_attr_description);
if (result)
goto end;
}
if (dev->pnp.type.bus_address)
result = device_create_file(&dev->dev, &dev_attr_adr);
if (dev->pnp.unique_id)
result = device_create_file(&dev->dev, &dev_attr_uid);
if (acpi_has_method(dev->handle, "_SUN")) {
result = device_create_file(&dev->dev, &dev_attr_sun);
if (result)
goto end;
}
if (acpi_has_method(dev->handle, "_STA")) {
result = device_create_file(&dev->dev, &dev_attr_status);
if (result)
goto end;
}
/*
* If device has _EJ0, 'eject' file is created that is used to trigger
* hot-removal function from userland.
*/
if (acpi_has_method(dev->handle, "_EJ0")) {
result = device_create_file(&dev->dev, &dev_attr_eject);
if (result)
return result;
}
if (dev->flags.power_manageable) {
result = device_create_file(&dev->dev, &dev_attr_power_state);
if (result)
return result;
if (dev->power.flags.power_resources)
result = device_create_file(&dev->dev,
&dev_attr_real_power_state);
}
acpi_expose_nondev_subnodes(&dev->dev.kobj, &dev->data);
end:
return result;
}
/**
* acpi_device_remove_files - Remove sysfs attributes of an ACPI device.
* @dev: ACPI device object.
*/
void acpi_device_remove_files(struct acpi_device *dev)
{
acpi_hide_nondev_subnodes(&dev->data);
if (dev->flags.power_manageable) {
device_remove_file(&dev->dev, &dev_attr_power_state);
if (dev->power.flags.power_resources)
device_remove_file(&dev->dev,
&dev_attr_real_power_state);
}
/*
* If device has _STR, remove 'description' file
*/
if (acpi_has_method(dev->handle, "_STR")) {
kfree(dev->pnp.str_obj);
device_remove_file(&dev->dev, &dev_attr_description);
}
/*
* If device has _EJ0, remove 'eject' file.
*/
if (acpi_has_method(dev->handle, "_EJ0"))
device_remove_file(&dev->dev, &dev_attr_eject);
if (acpi_has_method(dev->handle, "_SUN"))
device_remove_file(&dev->dev, &dev_attr_sun);
if (dev->pnp.unique_id)
device_remove_file(&dev->dev, &dev_attr_uid);
if (dev->pnp.type.bus_address)
device_remove_file(&dev->dev, &dev_attr_adr);
device_remove_file(&dev->dev, &dev_attr_modalias);
device_remove_file(&dev->dev, &dev_attr_hid);
if (acpi_has_method(dev->handle, "_STA"))
device_remove_file(&dev->dev, &dev_attr_status);
if (dev->handle)
device_remove_file(&dev->dev, &dev_attr_path);
}