/*
 * class.c - basic device class management
 *
 * Copyright (c) 2002-3 Patrick Mochel
 * Copyright (c) 2002-3 Open Source Development Labs
 * Copyright (c) 2003-2004 Greg Kroah-Hartman
 * Copyright (c) 2003-2004 IBM Corp.
 *
 * This file is released under the GPLv2
 *
 */

#include <linux/config.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/string.h>
#include "base.h"

#define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr)
#define to_class(obj) container_of(obj, struct class, subsys.kset.kobj)

static ssize_t
class_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
{
        struct class_attribute * class_attr = to_class_attr(attr);
        struct class * dc = to_class(kobj);
        ssize_t ret = 0;

        if (class_attr->show)
                ret = class_attr->show(dc, buf);
        return ret;
}

static ssize_t
class_attr_store(struct kobject * kobj, struct attribute * attr,
                 const char * buf, size_t count)
{
        struct class_attribute * class_attr = to_class_attr(attr);
        struct class * dc = to_class(kobj);
        ssize_t ret = 0;

        if (class_attr->store)
                ret = class_attr->store(dc, buf, count);
        return ret;
}

static void class_release(struct kobject * kobj)
{
        struct class *class = to_class(kobj);

        pr_debug("class '%s': release.\n", class->name);

        if (class->class_release)
                class->class_release(class);
        else
                pr_debug("class '%s' does not have a release() function, "
                         "be careful\n", class->name);
}

static struct sysfs_ops class_sysfs_ops = {
        .show   = class_attr_show,
        .store  = class_attr_store,
};

static struct kobj_type ktype_class = {
        .sysfs_ops      = &class_sysfs_ops,
        .release        = class_release,
};

/* Hotplug events for classes go to the class_obj subsys */
static decl_subsys(class, &ktype_class, NULL);


int class_create_file(struct class * cls, const struct class_attribute * attr)
{
        int error;
        if (cls) {
                error = sysfs_create_file(&cls->subsys.kset.kobj, &attr->attr);
        } else
                error = -EINVAL;
        return error;
}

void class_remove_file(struct class * cls, const struct class_attribute * attr)
{
        if (cls)
                sysfs_remove_file(&cls->subsys.kset.kobj, &attr->attr);
}

struct class * class_get(struct class * cls)
{
        if (cls)
                return container_of(subsys_get(&cls->subsys), struct class, subsys);
        return NULL;
}

void class_put(struct class * cls)
{
        subsys_put(&cls->subsys);
}


static int add_class_attrs(struct class * cls)
{
        int i;
        int error = 0;

        if (cls->class_attrs) {
                for (i = 0; attr_name(cls->class_attrs[i]); i++) {
                        error = class_create_file(cls,&cls->class_attrs[i]);
                        if (error)
                                goto Err;
                }
        }
 Done:
        return error;
 Err:
        while (--i >= 0)
                class_remove_file(cls,&cls->class_attrs[i]);
        goto Done;
}

static void remove_class_attrs(struct class * cls)
{
        int i;

        if (cls->class_attrs) {
                for (i = 0; attr_name(cls->class_attrs[i]); i++)
                        class_remove_file(cls,&cls->class_attrs[i]);
        }
}

int class_register(struct class * cls)
{
        int error;

        pr_debug("device class '%s': registering\n", cls->name);

        INIT_LIST_HEAD(&cls->children);
        INIT_LIST_HEAD(&cls->interfaces);
        error = kobject_set_name(&cls->subsys.kset.kobj, "%s", cls->name);
        if (error)
                return error;

        subsys_set_kset(cls, class_subsys);

        error = subsystem_register(&cls->subsys);
        if (!error) {
                error = add_class_attrs(class_get(cls));
                class_put(cls);
        }
        return error;
}

void class_unregister(struct class * cls)
{
        pr_debug("device class '%s': unregistering\n", cls->name);
        remove_class_attrs(cls);
        subsystem_unregister(&cls->subsys);
}


/* Class Device Stuff */

int class_device_create_file(struct class_device * class_dev,
                             const struct class_device_attribute * attr)
{
        int error = -EINVAL;
        if (class_dev)
                error = sysfs_create_file(&class_dev->kobj, &attr->attr);
        return error;
}

void class_device_remove_file(struct class_device * class_dev,
                              const struct class_device_attribute * attr)
{
        if (class_dev)
                sysfs_remove_file(&class_dev->kobj, &attr->attr);
}

int class_device_create_bin_file(struct class_device *class_dev,
                                 struct bin_attribute *attr)
{
        int error = -EINVAL;
        if (class_dev)
                error = sysfs_create_bin_file(&class_dev->kobj, attr);
        return error;
}

void class_device_remove_bin_file(struct class_device *class_dev,
                                  struct bin_attribute *attr)
{
        if (class_dev)
                sysfs_remove_bin_file(&class_dev->kobj, attr);
}

static int class_device_dev_link(struct class_device * class_dev)
{
        if (class_dev->dev)
                return sysfs_create_link(&class_dev->kobj,
                                         &class_dev->dev->kobj, "device");
        return 0;
}

static void class_device_dev_unlink(struct class_device * class_dev)
{
        sysfs_remove_link(&class_dev->kobj, "device");
}

static int class_device_driver_link(struct class_device * class_dev)
{
        if ((class_dev->dev) && (class_dev->dev->driver))
                return sysfs_create_link(&class_dev->kobj,
                                         &class_dev->dev->driver->kobj, "driver");
        return 0;
}

static void class_device_driver_unlink(struct class_device * class_dev)
{
        sysfs_remove_link(&class_dev->kobj, "driver");
}


static ssize_t
class_device_attr_show(struct kobject * kobj, struct attribute * attr,
                       char * buf)
{
        struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
        struct class_device * cd = to_class_dev(kobj);
        ssize_t ret = 0;

        if (class_dev_attr->show)
                ret = class_dev_attr->show(cd, buf);
        return ret;
}

static ssize_t
class_device_attr_store(struct kobject * kobj, struct attribute * attr,
                        const char * buf, size_t count)
{
        struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
        struct class_device * cd = to_class_dev(kobj);
        ssize_t ret = 0;

        if (class_dev_attr->store)
                ret = class_dev_attr->store(cd, buf, count);
        return ret;
}

static struct sysfs_ops class_dev_sysfs_ops = {
        .show   = class_device_attr_show,
        .store  = class_device_attr_store,
};

static void class_dev_release(struct kobject * kobj)
{
        struct class_device *cd = to_class_dev(kobj);
        struct class * cls = cd->class;

        pr_debug("device class '%s': release.\n", cd->class_id);

        if (cls->release)
                cls->release(cd);
        else {
                printk(KERN_ERR "Device class '%s' does not have a release() function, "
                        "it is broken and must be fixed.\n",
                        cd->class_id);
                WARN_ON(1);
        }
}

static struct kobj_type ktype_class_device = {
        .sysfs_ops      = &class_dev_sysfs_ops,
        .release        = class_dev_release,
};

static int class_hotplug_filter(struct kset *kset, struct kobject *kobj)
{
        struct kobj_type *ktype = get_ktype(kobj);

        if (ktype == &ktype_class_device) {
                struct class_device *class_dev = to_class_dev(kobj);
                if (class_dev->class)
                        return 1;
        }
        return 0;
}

static char *class_hotplug_name(struct kset *kset, struct kobject *kobj)
{
        struct class_device *class_dev = to_class_dev(kobj);

        return class_dev->class->name;
}

static int class_hotplug(struct kset *kset, struct kobject *kobj, char **envp,
                         int num_envp, char *buffer, int buffer_size)
{
        struct class_device *class_dev = to_class_dev(kobj);
        int retval = 0;
        int i = 0;
        int length = 0;

        pr_debug("%s - name = %s\n", __FUNCTION__, class_dev->class_id);

        if (class_dev->dev) {
                /* add physical device, backing this device  */
                struct device *dev = class_dev->dev;
                char *path = kobject_get_path(&dev->kobj, GFP_KERNEL);

                add_hotplug_env_var(envp, num_envp, &i, buffer, buffer_size,
                                    &length, "PHYSDEVPATH=%s", path);
                kfree(path);

                /* add bus name of physical device */
                if (dev->bus)
                        add_hotplug_env_var(envp, num_envp, &i,
                                            buffer, buffer_size, &length,
                                            "PHYSDEVBUS=%s", dev->bus->name);

                /* add driver name of physical device */
                if (dev->driver)
                        add_hotplug_env_var(envp, num_envp, &i,
                                            buffer, buffer_size, &length,
                                            "PHYSDEVDRIVER=%s", dev->driver->name);

                /* terminate, set to next free slot, shrink available space */
                envp[i] = NULL;
                envp = &envp[i];
                num_envp -= i;
                buffer = &buffer[length];
                buffer_size -= length;
        }

        if (class_dev->class->hotplug) {
                /* have the bus specific function add its stuff */
                retval = class_dev->class->hotplug (class_dev, envp, num_envp,
                                                    buffer, buffer_size);
                        if (retval) {
                        pr_debug ("%s - hotplug() returned %d\n",
                                  __FUNCTION__, retval);
                }
        }

        return retval;
}

static struct kset_hotplug_ops class_hotplug_ops = {
        .filter =       class_hotplug_filter,
        .name =         class_hotplug_name,
        .hotplug =      class_hotplug,
};

static decl_subsys(class_obj, &ktype_class_device, &class_hotplug_ops);


static int class_device_add_attrs(struct class_device * cd)
{
        int i;
        int error = 0;
        struct class * cls = cd->class;

        if (cls->class_dev_attrs) {
                for (i = 0; attr_name(cls->class_dev_attrs[i]); i++) {
                        error = class_device_create_file(cd,
                                                         &cls->class_dev_attrs[i]);
                        if (error)
                                goto Err;
                }
        }
 Done:
        return error;
 Err:
        while (--i >= 0)
                class_device_remove_file(cd,&cls->class_dev_attrs[i]);
        goto Done;
}

static void class_device_remove_attrs(struct class_device * cd)
{
        int i;
        struct class * cls = cd->class;

        if (cls->class_dev_attrs) {
                for (i = 0; attr_name(cls->class_dev_attrs[i]); i++)
                        class_device_remove_file(cd,&cls->class_dev_attrs[i]);
        }
}

void class_device_initialize(struct class_device *class_dev)
{
        kobj_set_kset_s(class_dev, class_obj_subsys);
        kobject_init(&class_dev->kobj);
        INIT_LIST_HEAD(&class_dev->node);
}

int class_device_add(struct class_device *class_dev)
{
        struct class * parent = NULL;
        struct class_interface * class_intf;
        int error;

        class_dev = class_device_get(class_dev);
        if (!class_dev)
                return -EINVAL;

        if (!strlen(class_dev->class_id)) {
                error = -EINVAL;
                goto register_done;
        }

        parent = class_get(class_dev->class);

        pr_debug("CLASS: registering class device: ID = '%s'\n",
                 class_dev->class_id);

        /* first, register with generic layer. */
        kobject_set_name(&class_dev->kobj, "%s", class_dev->class_id);
        if (parent)
                class_dev->kobj.parent = &parent->subsys.kset.kobj;

        if ((error = kobject_add(&class_dev->kobj)))
                goto register_done;

        /* now take care of our own registration */
        if (parent) {
                down_write(&parent->subsys.rwsem);
                list_add_tail(&class_dev->node, &parent->children);
                list_for_each_entry(class_intf, &parent->interfaces, node)
                        if (class_intf->add)
                                class_intf->add(class_dev);
                up_write(&parent->subsys.rwsem);
        }
        class_device_add_attrs(class_dev);
        class_device_dev_link(class_dev);
        class_device_driver_link(class_dev);

 register_done:
        if (error && parent)
                class_put(parent);
        class_device_put(class_dev);
        return error;
}

int class_device_register(struct class_device *class_dev)
{
        class_device_initialize(class_dev);
        return class_device_add(class_dev);
}

void class_device_del(struct class_device *class_dev)
{
        struct class * parent = class_dev->class;
        struct class_interface * class_intf;

        if (parent) {
                down_write(&parent->subsys.rwsem);
                list_del_init(&class_dev->node);
                list_for_each_entry(class_intf, &parent->interfaces, node)
                        if (class_intf->remove)
                                class_intf->remove(class_dev);
                up_write(&parent->subsys.rwsem);
        }

        class_device_dev_unlink(class_dev);
        class_device_driver_unlink(class_dev);
        class_device_remove_attrs(class_dev);

        kobject_del(&class_dev->kobj);

        if (parent)
                class_put(parent);
}

void class_device_unregister(struct class_device *class_dev)
{
        pr_debug("CLASS: Unregistering class device. ID = '%s'\n",
                 class_dev->class_id);
        class_device_del(class_dev);
        class_device_put(class_dev);
}

int class_device_rename(struct class_device *class_dev, char *new_name)
{
        int error = 0;

        class_dev = class_device_get(class_dev);
        if (!class_dev)
                return -EINVAL;

        pr_debug("CLASS: renaming '%s' to '%s'\n", class_dev->class_id,
                 new_name);

        strlcpy(class_dev->class_id, new_name, KOBJ_NAME_LEN);

        error = kobject_rename(&class_dev->kobj, new_name);

        class_device_put(class_dev);

        return error;
}

struct class_device * class_device_get(struct class_device *class_dev)
{
        if (class_dev)
                return to_class_dev(kobject_get(&class_dev->kobj));
        return NULL;
}

void class_device_put(struct class_device *class_dev)
{
        kobject_put(&class_dev->kobj);
}


int class_interface_register(struct class_interface *class_intf)
{
        struct class * parent;
        struct class_device * class_dev;

        if (!class_intf || !class_intf->class)
                return -ENODEV;

        parent = class_get(class_intf->class);
        if (!parent)
                return -EINVAL;

        down_write(&parent->subsys.rwsem);
        list_add_tail(&class_intf->node, &parent->interfaces);

        if (class_intf->add) {
                list_for_each_entry(class_dev, &parent->children, node)
                        class_intf->add(class_dev);
        }
        up_write(&parent->subsys.rwsem);

        return 0;
}

void class_interface_unregister(struct class_interface *class_intf)
{
        struct class * parent = class_intf->class;
        struct class_device *class_dev;

        if (!parent)
                return;

        down_write(&parent->subsys.rwsem);
        list_del_init(&class_intf->node);

        if (class_intf->remove) {
                list_for_each_entry(class_dev, &parent->children, node)
                        class_intf->remove(class_dev);
        }
        up_write(&parent->subsys.rwsem);

        class_put(parent);
}



int __init classes_init(void)
{
        int retval;

        retval = subsystem_register(&class_subsys);
        if (retval)
                return retval;

        /* ick, this is ugly, the things we go through to keep from showing up
         * in sysfs... */
        subsystem_init(&class_obj_subsys);
        if (!class_obj_subsys.kset.subsys)
                        class_obj_subsys.kset.subsys = &class_obj_subsys;
        return 0;
}

EXPORT_SYMBOL_GPL(class_create_file);
EXPORT_SYMBOL_GPL(class_remove_file);
EXPORT_SYMBOL_GPL(class_register);
EXPORT_SYMBOL_GPL(class_unregister);
EXPORT_SYMBOL_GPL(class_get);
EXPORT_SYMBOL_GPL(class_put);

EXPORT_SYMBOL_GPL(class_device_register);
EXPORT_SYMBOL_GPL(class_device_unregister);
EXPORT_SYMBOL_GPL(class_device_initialize);
EXPORT_SYMBOL_GPL(class_device_add);
EXPORT_SYMBOL_GPL(class_device_del);
EXPORT_SYMBOL_GPL(class_device_get);
EXPORT_SYMBOL_GPL(class_device_put);
EXPORT_SYMBOL_GPL(class_device_create_file);
EXPORT_SYMBOL_GPL(class_device_remove_file);
EXPORT_SYMBOL_GPL(class_device_create_bin_file);
EXPORT_SYMBOL_GPL(class_device_remove_bin_file);

EXPORT_SYMBOL_GPL(class_interface_register);
EXPORT_SYMBOL_GPL(class_interface_unregister);