1 files changed, 376 insertions, 0 deletions

diff --git a/drivers/base/attribute_container.c b/drivers/base/attribute_container.c
new file mode 100644
index 000000000000..ec615d854be9
--- /dev/null
+++ b/drivers/base/attribute_container.c
@@ -0,0 +1,376 @@
+/*
+ * 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/init.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/list.h>
+#include <linux/module.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 list_head node;
+        struct attribute_container *cont;
+        struct class_device 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 class_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 struct list_head attribute_container_list;
+
+static DECLARE_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);
+        INIT_LIST_HEAD(&cont->containers);
+                
+        down(&attribute_container_mutex);
+        list_add_tail(&cont->node, &attribute_container_list);
+        up(&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;
+        down(&attribute_container_mutex);
+        if (!list_empty(&cont->containers))
+                goto out;
+        retval = 0;
+        list_del(&cont->node);
+ out:
+        up(&attribute_container_mutex);
+        return retval;
+                
+}
+EXPORT_SYMBOL_GPL(attribute_container_unregister);
+
+/* private function used as class release */
+static void attribute_container_release(struct class_device *classdev)
+{
+        struct internal_container *ic 
+                = container_of(classdev, struct internal_container, classdev);
+        struct device *dev = classdev->dev;
+
+        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
+ * class_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 class_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 class_device *))
+{
+        struct attribute_container *cont;
+
+        down(&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 = kmalloc(sizeof(struct internal_container), GFP_KERNEL);
+                if (!ic) {
+                        dev_printk(KERN_ERR, dev, "failed to allocate class container\n");
+                        continue;
+                }
+                memset(ic, 0, sizeof(struct internal_container));
+                INIT_LIST_HEAD(&ic->node);
+                ic->cont = cont;
+                class_device_initialize(&ic->classdev);
+                ic->classdev.dev = get_device(dev);
+                ic->classdev.class = cont->class;
+                cont->class->release = attribute_container_release;
+                strcpy(ic->classdev.class_id, dev->bus_id);
+                if (fn)
+                        fn(cont, dev, &ic->classdev);
+                else
+                        attribute_container_add_class_device(&ic->classdev);
+                list_add_tail(&ic->node, &cont->containers);
+        }
+        up(&attribute_container_mutex);
+}
+
+/**
+ * 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 class_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
+ * class_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 class_device *))
+{
+        struct attribute_container *cont;
+
+        down(&attribute_container_mutex);
+        list_for_each_entry(cont, &attribute_container_list, node) {
+                struct internal_container *ic, *tmp;
+
+                if (attribute_container_no_classdevs(cont))
+                        continue;
+
+                if (!cont->match(cont, dev))
+                        continue;
+                list_for_each_entry_safe(ic, tmp, &cont->containers, node) {
+                        if (dev != ic->classdev.dev)
+                                continue;
+                        list_del(&ic->node);
+                        if (fn)
+                                fn(cont, dev, &ic->classdev);
+                        else {
+                                attribute_container_remove_attrs(&ic->classdev);
+                                class_device_unregister(&ic->classdev);
+                        }
+                }
+        }
+        up(&attribute_container_mutex);
+}
+EXPORT_SYMBOL_GPL(attribute_container_remove_device);
+
+/**
+ * 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 funcion 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 class_device *))
+{
+        struct attribute_container *cont;
+
+        down(&attribute_container_mutex);
+        list_for_each_entry(cont, &attribute_container_list, node) {
+                struct internal_container *ic, *tmp;
+
+                if (!cont->match(cont, dev))
+                        continue;
+
+                list_for_each_entry_safe(ic, tmp, &cont->containers, node) {
+                        if (dev == ic->classdev.dev)
+                                fn(cont, dev, &ic->classdev);
+                }
+        }
+        up(&attribute_container_mutex);
+}
+EXPORT_SYMBOL_GPL(attribute_container_device_trigger);
+
+/**
+ * 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;
+
+        down(&attribute_container_mutex);
+        list_for_each_entry(cont, &attribute_container_list, node) {
+                if (cont->match(cont, dev))
+                        fn(cont, dev);
+        }
+        up(&attribute_container_mutex);
+}
+EXPORT_SYMBOL_GPL(attribute_container_trigger);
+
+/**
+ * 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 class_device *classdev)
+{
+        struct attribute_container *cont =
+                attribute_container_classdev_to_container(classdev);
+        struct class_device_attribute **attrs = cont->attrs;
+        int i, error;
+
+        if (!attrs)
+                return 0;
+
+        for (i = 0; attrs[i]; i++) {
+                error = class_device_create_file(classdev, attrs[i]);
+                if (error)
+                        return error;
+        }
+
+        return 0;
+}
+EXPORT_SYMBOL_GPL(attribute_container_add_attrs);
+
+/**
+ * attribute_container_add_class_device - same function as class_device_add
+ *
+ * @classdev:   the class device to add
+ *
+ * This performs essentially the same function as class_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 class_device *classdev)
+{
+        int error = class_device_add(classdev);
+        if (error)
+                return error;
+        return attribute_container_add_attrs(classdev);
+}
+EXPORT_SYMBOL_GPL(attribute_container_add_class_device);
+
+/**
+ * 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 class_device *classdev)
+{
+        return attribute_container_add_class_device(classdev);
+}
+EXPORT_SYMBOL_GPL(attribute_container_add_class_device_adapter);
+
+/**
+ * attribute_container_remove_attrs - remove any attribute files
+ *
+ * @classdev: The class device to remove the files from
+ *
+ */
+void
+attribute_container_remove_attrs(struct class_device *classdev)
+{
+        struct attribute_container *cont =
+                attribute_container_classdev_to_container(classdev);
+        struct class_device_attribute **attrs = cont->attrs;
+        int i;
+
+        if (!attrs)
+                return;
+
+        for (i = 0; attrs[i]; i++)
+                class_device_remove_file(classdev, attrs[i]);
+}
+EXPORT_SYMBOL_GPL(attribute_container_remove_attrs);
+
+/**
+ * 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
+ * class_device_del.
+ */
+void
+attribute_container_class_device_del(struct class_device *classdev)
+{
+        attribute_container_remove_attrs(classdev);
+        class_device_del(classdev);
+}
+EXPORT_SYMBOL_GPL(attribute_container_class_device_del);
+
+int __init
+attribute_container_init(void)
+{
+        INIT_LIST_HEAD(&attribute_container_list);
+        return 0;
+}