443 строки
12 KiB
C
443 строки
12 KiB
C
/*
|
|
* attribute_container.c - implementation of a simple container for classes
|
|
*
|
|
* Copyright (c) 2005 - James Bottomley <James.Bottomley@steeleye.com>
|
|
*
|
|
* This file is licensed under GPLv2
|
|
*
|
|
* The basic idea here is to enable a device to be attached to an
|
|
* aritrary numer of classes without having to allocate storage for them.
|
|
* Instead, the contained classes select the devices they need to attach
|
|
* to via a matching function.
|
|
*/
|
|
|
|
#include <linux/attribute_container.h>
|
|
#include <linux/device.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/list.h>
|
|
#include <linux/module.h>
|
|
#include <linux/mutex.h>
|
|
|
|
#include "base.h"
|
|
|
|
/* This is a private structure used to tie the classdev and the
|
|
* container .. it should never be visible outside this file */
|
|
struct internal_container {
|
|
struct klist_node node;
|
|
struct attribute_container *cont;
|
|
struct device classdev;
|
|
};
|
|
|
|
static void internal_container_klist_get(struct klist_node *n)
|
|
{
|
|
struct internal_container *ic =
|
|
container_of(n, struct internal_container, node);
|
|
get_device(&ic->classdev);
|
|
}
|
|
|
|
static void internal_container_klist_put(struct klist_node *n)
|
|
{
|
|
struct internal_container *ic =
|
|
container_of(n, struct internal_container, node);
|
|
put_device(&ic->classdev);
|
|
}
|
|
|
|
|
|
/**
|
|
* attribute_container_classdev_to_container - given a classdev, return the container
|
|
*
|
|
* @classdev: the class device created by attribute_container_add_device.
|
|
*
|
|
* Returns the container associated with this classdev.
|
|
*/
|
|
struct attribute_container *
|
|
attribute_container_classdev_to_container(struct device *classdev)
|
|
{
|
|
struct internal_container *ic =
|
|
container_of(classdev, struct internal_container, classdev);
|
|
return ic->cont;
|
|
}
|
|
EXPORT_SYMBOL_GPL(attribute_container_classdev_to_container);
|
|
|
|
static LIST_HEAD(attribute_container_list);
|
|
|
|
static DEFINE_MUTEX(attribute_container_mutex);
|
|
|
|
/**
|
|
* attribute_container_register - register an attribute container
|
|
*
|
|
* @cont: The container to register. This must be allocated by the
|
|
* callee and should also be zeroed by it.
|
|
*/
|
|
int
|
|
attribute_container_register(struct attribute_container *cont)
|
|
{
|
|
INIT_LIST_HEAD(&cont->node);
|
|
klist_init(&cont->containers, internal_container_klist_get,
|
|
internal_container_klist_put);
|
|
|
|
mutex_lock(&attribute_container_mutex);
|
|
list_add_tail(&cont->node, &attribute_container_list);
|
|
mutex_unlock(&attribute_container_mutex);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(attribute_container_register);
|
|
|
|
/**
|
|
* attribute_container_unregister - remove a container registration
|
|
*
|
|
* @cont: previously registered container to remove
|
|
*/
|
|
int
|
|
attribute_container_unregister(struct attribute_container *cont)
|
|
{
|
|
int retval = -EBUSY;
|
|
|
|
mutex_lock(&attribute_container_mutex);
|
|
spin_lock(&cont->containers.k_lock);
|
|
if (!list_empty(&cont->containers.k_list))
|
|
goto out;
|
|
retval = 0;
|
|
list_del(&cont->node);
|
|
out:
|
|
spin_unlock(&cont->containers.k_lock);
|
|
mutex_unlock(&attribute_container_mutex);
|
|
return retval;
|
|
|
|
}
|
|
EXPORT_SYMBOL_GPL(attribute_container_unregister);
|
|
|
|
/* private function used as class release */
|
|
static void attribute_container_release(struct device *classdev)
|
|
{
|
|
struct internal_container *ic
|
|
= container_of(classdev, struct internal_container, classdev);
|
|
struct device *dev = classdev->parent;
|
|
|
|
kfree(ic);
|
|
put_device(dev);
|
|
}
|
|
|
|
/**
|
|
* attribute_container_add_device - see if any container is interested in dev
|
|
*
|
|
* @dev: device to add attributes to
|
|
* @fn: function to trigger addition of class device.
|
|
*
|
|
* This function allocates storage for the class device(s) to be
|
|
* attached to dev (one for each matching attribute_container). If no
|
|
* fn is provided, the code will simply register the class device via
|
|
* device_add. If a function is provided, it is expected to add
|
|
* the class device at the appropriate time. One of the things that
|
|
* might be necessary is to allocate and initialise the classdev and
|
|
* then add it a later time. To do this, call this routine for
|
|
* allocation and initialisation and then use
|
|
* attribute_container_device_trigger() to call device_add() on
|
|
* it. Note: after this, the class device contains a reference to dev
|
|
* which is not relinquished until the release of the classdev.
|
|
*/
|
|
void
|
|
attribute_container_add_device(struct device *dev,
|
|
int (*fn)(struct attribute_container *,
|
|
struct device *,
|
|
struct device *))
|
|
{
|
|
struct attribute_container *cont;
|
|
|
|
mutex_lock(&attribute_container_mutex);
|
|
list_for_each_entry(cont, &attribute_container_list, node) {
|
|
struct internal_container *ic;
|
|
|
|
if (attribute_container_no_classdevs(cont))
|
|
continue;
|
|
|
|
if (!cont->match(cont, dev))
|
|
continue;
|
|
|
|
ic = kzalloc(sizeof(*ic), GFP_KERNEL);
|
|
if (!ic) {
|
|
dev_err(dev, "failed to allocate class container\n");
|
|
continue;
|
|
}
|
|
|
|
ic->cont = cont;
|
|
device_initialize(&ic->classdev);
|
|
ic->classdev.parent = get_device(dev);
|
|
ic->classdev.class = cont->class;
|
|
cont->class->dev_release = attribute_container_release;
|
|
dev_set_name(&ic->classdev, "%s", dev_name(dev));
|
|
if (fn)
|
|
fn(cont, dev, &ic->classdev);
|
|
else
|
|
attribute_container_add_class_device(&ic->classdev);
|
|
klist_add_tail(&ic->node, &cont->containers);
|
|
}
|
|
mutex_unlock(&attribute_container_mutex);
|
|
}
|
|
|
|
/* FIXME: can't break out of this unless klist_iter_exit is also
|
|
* called before doing the break
|
|
*/
|
|
#define klist_for_each_entry(pos, head, member, iter) \
|
|
for (klist_iter_init(head, iter); (pos = ({ \
|
|
struct klist_node *n = klist_next(iter); \
|
|
n ? container_of(n, typeof(*pos), member) : \
|
|
({ klist_iter_exit(iter) ; NULL; }); \
|
|
})) != NULL;)
|
|
|
|
|
|
/**
|
|
* attribute_container_remove_device - make device eligible for removal.
|
|
*
|
|
* @dev: The generic device
|
|
* @fn: A function to call to remove the device
|
|
*
|
|
* This routine triggers device removal. If fn is NULL, then it is
|
|
* simply done via device_unregister (note that if something
|
|
* still has a reference to the classdev, then the memory occupied
|
|
* will not be freed until the classdev is released). If you want a
|
|
* two phase release: remove from visibility and then delete the
|
|
* device, then you should use this routine with a fn that calls
|
|
* device_del() and then use attribute_container_device_trigger()
|
|
* to do the final put on the classdev.
|
|
*/
|
|
void
|
|
attribute_container_remove_device(struct device *dev,
|
|
void (*fn)(struct attribute_container *,
|
|
struct device *,
|
|
struct device *))
|
|
{
|
|
struct attribute_container *cont;
|
|
|
|
mutex_lock(&attribute_container_mutex);
|
|
list_for_each_entry(cont, &attribute_container_list, node) {
|
|
struct internal_container *ic;
|
|
struct klist_iter iter;
|
|
|
|
if (attribute_container_no_classdevs(cont))
|
|
continue;
|
|
|
|
if (!cont->match(cont, dev))
|
|
continue;
|
|
|
|
klist_for_each_entry(ic, &cont->containers, node, &iter) {
|
|
if (dev != ic->classdev.parent)
|
|
continue;
|
|
klist_del(&ic->node);
|
|
if (fn)
|
|
fn(cont, dev, &ic->classdev);
|
|
else {
|
|
attribute_container_remove_attrs(&ic->classdev);
|
|
device_unregister(&ic->classdev);
|
|
}
|
|
}
|
|
}
|
|
mutex_unlock(&attribute_container_mutex);
|
|
}
|
|
|
|
/**
|
|
* attribute_container_device_trigger - execute a trigger for each matching classdev
|
|
*
|
|
* @dev: The generic device to run the trigger for
|
|
* @fn the function to execute for each classdev.
|
|
*
|
|
* This function is for executing a trigger when you need to know both
|
|
* the container and the classdev. If you only care about the
|
|
* container, then use attribute_container_trigger() instead.
|
|
*/
|
|
void
|
|
attribute_container_device_trigger(struct device *dev,
|
|
int (*fn)(struct attribute_container *,
|
|
struct device *,
|
|
struct device *))
|
|
{
|
|
struct attribute_container *cont;
|
|
|
|
mutex_lock(&attribute_container_mutex);
|
|
list_for_each_entry(cont, &attribute_container_list, node) {
|
|
struct internal_container *ic;
|
|
struct klist_iter iter;
|
|
|
|
if (!cont->match(cont, dev))
|
|
continue;
|
|
|
|
if (attribute_container_no_classdevs(cont)) {
|
|
fn(cont, dev, NULL);
|
|
continue;
|
|
}
|
|
|
|
klist_for_each_entry(ic, &cont->containers, node, &iter) {
|
|
if (dev == ic->classdev.parent)
|
|
fn(cont, dev, &ic->classdev);
|
|
}
|
|
}
|
|
mutex_unlock(&attribute_container_mutex);
|
|
}
|
|
|
|
/**
|
|
* attribute_container_trigger - trigger a function for each matching container
|
|
*
|
|
* @dev: The generic device to activate the trigger for
|
|
* @fn: the function to trigger
|
|
*
|
|
* This routine triggers a function that only needs to know the
|
|
* matching containers (not the classdev) associated with a device.
|
|
* It is more lightweight than attribute_container_device_trigger, so
|
|
* should be used in preference unless the triggering function
|
|
* actually needs to know the classdev.
|
|
*/
|
|
void
|
|
attribute_container_trigger(struct device *dev,
|
|
int (*fn)(struct attribute_container *,
|
|
struct device *))
|
|
{
|
|
struct attribute_container *cont;
|
|
|
|
mutex_lock(&attribute_container_mutex);
|
|
list_for_each_entry(cont, &attribute_container_list, node) {
|
|
if (cont->match(cont, dev))
|
|
fn(cont, dev);
|
|
}
|
|
mutex_unlock(&attribute_container_mutex);
|
|
}
|
|
|
|
/**
|
|
* attribute_container_add_attrs - add attributes
|
|
*
|
|
* @classdev: The class device
|
|
*
|
|
* This simply creates all the class device sysfs files from the
|
|
* attributes listed in the container
|
|
*/
|
|
int
|
|
attribute_container_add_attrs(struct device *classdev)
|
|
{
|
|
struct attribute_container *cont =
|
|
attribute_container_classdev_to_container(classdev);
|
|
struct device_attribute **attrs = cont->attrs;
|
|
int i, error;
|
|
|
|
BUG_ON(attrs && cont->grp);
|
|
|
|
if (!attrs && !cont->grp)
|
|
return 0;
|
|
|
|
if (cont->grp)
|
|
return sysfs_create_group(&classdev->kobj, cont->grp);
|
|
|
|
for (i = 0; attrs[i]; i++) {
|
|
sysfs_attr_init(&attrs[i]->attr);
|
|
error = device_create_file(classdev, attrs[i]);
|
|
if (error)
|
|
return error;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* attribute_container_add_class_device - same function as device_add
|
|
*
|
|
* @classdev: the class device to add
|
|
*
|
|
* This performs essentially the same function as device_add except for
|
|
* attribute containers, namely add the classdev to the system and then
|
|
* create the attribute files
|
|
*/
|
|
int
|
|
attribute_container_add_class_device(struct device *classdev)
|
|
{
|
|
int error = device_add(classdev);
|
|
|
|
if (error)
|
|
return error;
|
|
return attribute_container_add_attrs(classdev);
|
|
}
|
|
|
|
/**
|
|
* attribute_container_add_class_device_adapter - simple adapter for triggers
|
|
*
|
|
* This function is identical to attribute_container_add_class_device except
|
|
* that it is designed to be called from the triggers
|
|
*/
|
|
int
|
|
attribute_container_add_class_device_adapter(struct attribute_container *cont,
|
|
struct device *dev,
|
|
struct device *classdev)
|
|
{
|
|
return attribute_container_add_class_device(classdev);
|
|
}
|
|
|
|
/**
|
|
* attribute_container_remove_attrs - remove any attribute files
|
|
*
|
|
* @classdev: The class device to remove the files from
|
|
*
|
|
*/
|
|
void
|
|
attribute_container_remove_attrs(struct device *classdev)
|
|
{
|
|
struct attribute_container *cont =
|
|
attribute_container_classdev_to_container(classdev);
|
|
struct device_attribute **attrs = cont->attrs;
|
|
int i;
|
|
|
|
if (!attrs && !cont->grp)
|
|
return;
|
|
|
|
if (cont->grp) {
|
|
sysfs_remove_group(&classdev->kobj, cont->grp);
|
|
return ;
|
|
}
|
|
|
|
for (i = 0; attrs[i]; i++)
|
|
device_remove_file(classdev, attrs[i]);
|
|
}
|
|
|
|
/**
|
|
* attribute_container_class_device_del - equivalent of class_device_del
|
|
*
|
|
* @classdev: the class device
|
|
*
|
|
* This function simply removes all the attribute files and then calls
|
|
* device_del.
|
|
*/
|
|
void
|
|
attribute_container_class_device_del(struct device *classdev)
|
|
{
|
|
attribute_container_remove_attrs(classdev);
|
|
device_del(classdev);
|
|
}
|
|
|
|
/**
|
|
* attribute_container_find_class_device - find the corresponding class_device
|
|
*
|
|
* @cont: the container
|
|
* @dev: the generic device
|
|
*
|
|
* Looks up the device in the container's list of class devices and returns
|
|
* the corresponding class_device.
|
|
*/
|
|
struct device *
|
|
attribute_container_find_class_device(struct attribute_container *cont,
|
|
struct device *dev)
|
|
{
|
|
struct device *cdev = NULL;
|
|
struct internal_container *ic;
|
|
struct klist_iter iter;
|
|
|
|
klist_for_each_entry(ic, &cont->containers, node, &iter) {
|
|
if (ic->classdev.parent == dev) {
|
|
cdev = &ic->classdev;
|
|
/* FIXME: must exit iterator then break */
|
|
klist_iter_exit(&iter);
|
|
break;
|
|
}
|
|
}
|
|
|
|
return cdev;
|
|
}
|
|
EXPORT_SYMBOL_GPL(attribute_container_find_class_device);
|