556 lines
14 KiB
C
556 lines
14 KiB
C
/*
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* sys.c - pseudo-bus for system 'devices' (cpus, PICs, timers, etc)
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*
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* Copyright (c) 2002-3 Patrick Mochel
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* 2002-3 Open Source Development Lab
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*
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* This file is released under the GPLv2
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*
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* This exports a 'system' bus type.
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* By default, a 'sys' bus gets added to the root of the system. There will
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* always be core system devices. Devices can use sysdev_register() to
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* add themselves as children of the system bus.
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*/
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#include <linux/sysdev.h>
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#include <linux/err.h>
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/string.h>
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#include <linux/pm.h>
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#include <linux/device.h>
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#include <linux/mutex.h>
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#include <linux/interrupt.h>
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#include "base.h"
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#define to_sysdev(k) container_of(k, struct sys_device, kobj)
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#define to_sysdev_attr(a) container_of(a, struct sysdev_attribute, attr)
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static ssize_t
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sysdev_show(struct kobject *kobj, struct attribute *attr, char *buffer)
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{
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struct sys_device *sysdev = to_sysdev(kobj);
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struct sysdev_attribute *sysdev_attr = to_sysdev_attr(attr);
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if (sysdev_attr->show)
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return sysdev_attr->show(sysdev, sysdev_attr, buffer);
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return -EIO;
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}
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static ssize_t
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sysdev_store(struct kobject *kobj, struct attribute *attr,
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const char *buffer, size_t count)
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{
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struct sys_device *sysdev = to_sysdev(kobj);
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struct sysdev_attribute *sysdev_attr = to_sysdev_attr(attr);
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if (sysdev_attr->store)
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return sysdev_attr->store(sysdev, sysdev_attr, buffer, count);
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return -EIO;
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}
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static struct sysfs_ops sysfs_ops = {
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.show = sysdev_show,
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.store = sysdev_store,
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};
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static struct kobj_type ktype_sysdev = {
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.sysfs_ops = &sysfs_ops,
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};
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int sysdev_create_file(struct sys_device *s, struct sysdev_attribute *a)
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{
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return sysfs_create_file(&s->kobj, &a->attr);
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}
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void sysdev_remove_file(struct sys_device *s, struct sysdev_attribute *a)
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{
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sysfs_remove_file(&s->kobj, &a->attr);
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}
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EXPORT_SYMBOL_GPL(sysdev_create_file);
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EXPORT_SYMBOL_GPL(sysdev_remove_file);
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#define to_sysdev_class(k) container_of(k, struct sysdev_class, kset.kobj)
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#define to_sysdev_class_attr(a) container_of(a, \
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struct sysdev_class_attribute, attr)
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static ssize_t sysdev_class_show(struct kobject *kobj, struct attribute *attr,
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char *buffer)
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{
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struct sysdev_class *class = to_sysdev_class(kobj);
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struct sysdev_class_attribute *class_attr = to_sysdev_class_attr(attr);
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if (class_attr->show)
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return class_attr->show(class, buffer);
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return -EIO;
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}
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static ssize_t sysdev_class_store(struct kobject *kobj, struct attribute *attr,
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const char *buffer, size_t count)
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{
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struct sysdev_class *class = to_sysdev_class(kobj);
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struct sysdev_class_attribute *class_attr = to_sysdev_class_attr(attr);
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if (class_attr->store)
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return class_attr->store(class, buffer, count);
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return -EIO;
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}
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static struct sysfs_ops sysfs_class_ops = {
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.show = sysdev_class_show,
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.store = sysdev_class_store,
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};
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static struct kobj_type ktype_sysdev_class = {
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.sysfs_ops = &sysfs_class_ops,
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};
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int sysdev_class_create_file(struct sysdev_class *c,
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struct sysdev_class_attribute *a)
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{
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return sysfs_create_file(&c->kset.kobj, &a->attr);
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}
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EXPORT_SYMBOL_GPL(sysdev_class_create_file);
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void sysdev_class_remove_file(struct sysdev_class *c,
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struct sysdev_class_attribute *a)
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{
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sysfs_remove_file(&c->kset.kobj, &a->attr);
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}
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EXPORT_SYMBOL_GPL(sysdev_class_remove_file);
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static struct kset *system_kset;
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int sysdev_class_register(struct sysdev_class *cls)
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{
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int retval;
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pr_debug("Registering sysdev class '%s'\n", cls->name);
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INIT_LIST_HEAD(&cls->drivers);
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memset(&cls->kset.kobj, 0x00, sizeof(struct kobject));
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cls->kset.kobj.parent = &system_kset->kobj;
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cls->kset.kobj.ktype = &ktype_sysdev_class;
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cls->kset.kobj.kset = system_kset;
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retval = kobject_set_name(&cls->kset.kobj, "%s", cls->name);
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if (retval)
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return retval;
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return kset_register(&cls->kset);
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}
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void sysdev_class_unregister(struct sysdev_class *cls)
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{
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pr_debug("Unregistering sysdev class '%s'\n",
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kobject_name(&cls->kset.kobj));
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kset_unregister(&cls->kset);
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}
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EXPORT_SYMBOL_GPL(sysdev_class_register);
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EXPORT_SYMBOL_GPL(sysdev_class_unregister);
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static DEFINE_MUTEX(sysdev_drivers_lock);
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/**
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* sysdev_driver_register - Register auxillary driver
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* @cls: Device class driver belongs to.
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* @drv: Driver.
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*
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* @drv is inserted into @cls->drivers to be
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* called on each operation on devices of that class. The refcount
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* of @cls is incremented.
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*/
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int sysdev_driver_register(struct sysdev_class *cls, struct sysdev_driver *drv)
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{
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int err = 0;
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if (!cls) {
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WARN(1, KERN_WARNING "sysdev: invalid class passed to "
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"sysdev_driver_register!\n");
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return -EINVAL;
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}
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/* Check whether this driver has already been added to a class. */
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if (drv->entry.next && !list_empty(&drv->entry))
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WARN(1, KERN_WARNING "sysdev: class %s: driver (%p) has already"
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" been registered to a class, something is wrong, but "
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"will forge on!\n", cls->name, drv);
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mutex_lock(&sysdev_drivers_lock);
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if (cls && kset_get(&cls->kset)) {
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list_add_tail(&drv->entry, &cls->drivers);
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/* If devices of this class already exist, tell the driver */
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if (drv->add) {
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struct sys_device *dev;
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list_for_each_entry(dev, &cls->kset.list, kobj.entry)
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drv->add(dev);
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}
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} else {
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err = -EINVAL;
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WARN(1, KERN_ERR "%s: invalid device class\n", __func__);
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}
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mutex_unlock(&sysdev_drivers_lock);
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return err;
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}
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/**
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* sysdev_driver_unregister - Remove an auxillary driver.
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* @cls: Class driver belongs to.
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* @drv: Driver.
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*/
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void sysdev_driver_unregister(struct sysdev_class *cls,
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struct sysdev_driver *drv)
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{
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mutex_lock(&sysdev_drivers_lock);
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list_del_init(&drv->entry);
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if (cls) {
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if (drv->remove) {
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struct sys_device *dev;
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list_for_each_entry(dev, &cls->kset.list, kobj.entry)
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drv->remove(dev);
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}
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kset_put(&cls->kset);
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}
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mutex_unlock(&sysdev_drivers_lock);
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}
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EXPORT_SYMBOL_GPL(sysdev_driver_register);
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EXPORT_SYMBOL_GPL(sysdev_driver_unregister);
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/**
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* sysdev_register - add a system device to the tree
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* @sysdev: device in question
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*
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*/
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int sysdev_register(struct sys_device *sysdev)
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{
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int error;
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struct sysdev_class *cls = sysdev->cls;
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if (!cls)
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return -EINVAL;
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pr_debug("Registering sys device of class '%s'\n",
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kobject_name(&cls->kset.kobj));
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/* initialize the kobject to 0, in case it had previously been used */
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memset(&sysdev->kobj, 0x00, sizeof(struct kobject));
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/* Make sure the kset is set */
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sysdev->kobj.kset = &cls->kset;
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/* Register the object */
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error = kobject_init_and_add(&sysdev->kobj, &ktype_sysdev, NULL,
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"%s%d", kobject_name(&cls->kset.kobj),
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sysdev->id);
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if (!error) {
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struct sysdev_driver *drv;
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pr_debug("Registering sys device '%s'\n",
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kobject_name(&sysdev->kobj));
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mutex_lock(&sysdev_drivers_lock);
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/* Generic notification is implicit, because it's that
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* code that should have called us.
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*/
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/* Notify class auxillary drivers */
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list_for_each_entry(drv, &cls->drivers, entry) {
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if (drv->add)
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drv->add(sysdev);
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}
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mutex_unlock(&sysdev_drivers_lock);
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kobject_uevent(&sysdev->kobj, KOBJ_ADD);
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}
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return error;
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}
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void sysdev_unregister(struct sys_device *sysdev)
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{
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struct sysdev_driver *drv;
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mutex_lock(&sysdev_drivers_lock);
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list_for_each_entry(drv, &sysdev->cls->drivers, entry) {
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if (drv->remove)
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drv->remove(sysdev);
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}
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mutex_unlock(&sysdev_drivers_lock);
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kobject_put(&sysdev->kobj);
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}
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/**
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* sysdev_shutdown - Shut down all system devices.
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*
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* Loop over each class of system devices, and the devices in each
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* of those classes. For each device, we call the shutdown method for
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* each driver registered for the device - the auxillaries,
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* and the class driver.
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*
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* Note: The list is iterated in reverse order, so that we shut down
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* child devices before we shut down their parents. The list ordering
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* is guaranteed by virtue of the fact that child devices are registered
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* after their parents.
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*/
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void sysdev_shutdown(void)
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{
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struct sysdev_class *cls;
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pr_debug("Shutting Down System Devices\n");
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mutex_lock(&sysdev_drivers_lock);
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list_for_each_entry_reverse(cls, &system_kset->list, kset.kobj.entry) {
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struct sys_device *sysdev;
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pr_debug("Shutting down type '%s':\n",
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kobject_name(&cls->kset.kobj));
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list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
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struct sysdev_driver *drv;
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pr_debug(" %s\n", kobject_name(&sysdev->kobj));
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/* Call auxillary drivers first */
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list_for_each_entry(drv, &cls->drivers, entry) {
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if (drv->shutdown)
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drv->shutdown(sysdev);
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}
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/* Now call the generic one */
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if (cls->shutdown)
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cls->shutdown(sysdev);
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}
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}
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mutex_unlock(&sysdev_drivers_lock);
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}
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static void __sysdev_resume(struct sys_device *dev)
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{
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struct sysdev_class *cls = dev->cls;
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struct sysdev_driver *drv;
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/* First, call the class-specific one */
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if (cls->resume)
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cls->resume(dev);
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WARN_ONCE(!irqs_disabled(),
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"Interrupts enabled after %pF\n", cls->resume);
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/* Call auxillary drivers next. */
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list_for_each_entry(drv, &cls->drivers, entry) {
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if (drv->resume)
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drv->resume(dev);
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WARN_ONCE(!irqs_disabled(),
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"Interrupts enabled after %pF\n", drv->resume);
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}
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}
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/**
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* sysdev_suspend - Suspend all system devices.
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* @state: Power state to enter.
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*
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* We perform an almost identical operation as sysdev_shutdown()
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* above, though calling ->suspend() instead. Interrupts are disabled
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* when this called. Devices are responsible for both saving state and
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* quiescing or powering down the device.
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*
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* This is only called by the device PM core, so we let them handle
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* all synchronization.
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*/
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int sysdev_suspend(pm_message_t state)
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{
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struct sysdev_class *cls;
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struct sys_device *sysdev, *err_dev;
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struct sysdev_driver *drv, *err_drv;
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int ret;
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pr_debug("Checking wake-up interrupts\n");
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/* Return error code if there are any wake-up interrupts pending */
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ret = check_wakeup_irqs();
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if (ret)
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return ret;
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WARN_ONCE(!irqs_disabled(),
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"Interrupts enabled while suspending system devices\n");
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pr_debug("Suspending System Devices\n");
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list_for_each_entry_reverse(cls, &system_kset->list, kset.kobj.entry) {
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pr_debug("Suspending type '%s':\n",
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kobject_name(&cls->kset.kobj));
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list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
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pr_debug(" %s\n", kobject_name(&sysdev->kobj));
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/* Call auxillary drivers first */
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list_for_each_entry(drv, &cls->drivers, entry) {
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if (drv->suspend) {
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ret = drv->suspend(sysdev, state);
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if (ret)
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goto aux_driver;
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}
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WARN_ONCE(!irqs_disabled(),
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"Interrupts enabled after %pF\n",
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drv->suspend);
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}
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/* Now call the generic one */
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if (cls->suspend) {
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ret = cls->suspend(sysdev, state);
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if (ret)
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goto cls_driver;
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WARN_ONCE(!irqs_disabled(),
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"Interrupts enabled after %pF\n",
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cls->suspend);
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}
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}
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}
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return 0;
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/* resume current sysdev */
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cls_driver:
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drv = NULL;
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printk(KERN_ERR "Class suspend failed for %s\n",
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kobject_name(&sysdev->kobj));
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aux_driver:
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if (drv)
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printk(KERN_ERR "Class driver suspend failed for %s\n",
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kobject_name(&sysdev->kobj));
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list_for_each_entry(err_drv, &cls->drivers, entry) {
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if (err_drv == drv)
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break;
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if (err_drv->resume)
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err_drv->resume(sysdev);
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}
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/* resume other sysdevs in current class */
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list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) {
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if (err_dev == sysdev)
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break;
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pr_debug(" %s\n", kobject_name(&err_dev->kobj));
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__sysdev_resume(err_dev);
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}
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/* resume other classes */
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list_for_each_entry_continue(cls, &system_kset->list, kset.kobj.entry) {
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list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) {
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pr_debug(" %s\n", kobject_name(&err_dev->kobj));
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__sysdev_resume(err_dev);
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}
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}
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return ret;
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}
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EXPORT_SYMBOL_GPL(sysdev_suspend);
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/**
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* sysdev_resume - Bring system devices back to life.
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*
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* Similar to sysdev_suspend(), but we iterate the list forwards
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* to guarantee that parent devices are resumed before their children.
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*
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* Note: Interrupts are disabled when called.
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*/
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int sysdev_resume(void)
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{
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struct sysdev_class *cls;
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WARN_ONCE(!irqs_disabled(),
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"Interrupts enabled while resuming system devices\n");
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pr_debug("Resuming System Devices\n");
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list_for_each_entry(cls, &system_kset->list, kset.kobj.entry) {
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struct sys_device *sysdev;
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pr_debug("Resuming type '%s':\n",
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kobject_name(&cls->kset.kobj));
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list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
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pr_debug(" %s\n", kobject_name(&sysdev->kobj));
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__sysdev_resume(sysdev);
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}
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}
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return 0;
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}
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EXPORT_SYMBOL_GPL(sysdev_resume);
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int __init system_bus_init(void)
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{
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system_kset = kset_create_and_add("system", NULL, &devices_kset->kobj);
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if (!system_kset)
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return -ENOMEM;
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return 0;
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}
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EXPORT_SYMBOL_GPL(sysdev_register);
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EXPORT_SYMBOL_GPL(sysdev_unregister);
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#define to_ext_attr(x) container_of(x, struct sysdev_ext_attribute, attr)
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ssize_t sysdev_store_ulong(struct sys_device *sysdev,
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struct sysdev_attribute *attr,
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const char *buf, size_t size)
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{
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struct sysdev_ext_attribute *ea = to_ext_attr(attr);
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char *end;
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unsigned long new = simple_strtoul(buf, &end, 0);
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if (end == buf)
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return -EINVAL;
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*(unsigned long *)(ea->var) = new;
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/* Always return full write size even if we didn't consume all */
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return size;
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}
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EXPORT_SYMBOL_GPL(sysdev_store_ulong);
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ssize_t sysdev_show_ulong(struct sys_device *sysdev,
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struct sysdev_attribute *attr,
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char *buf)
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{
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struct sysdev_ext_attribute *ea = to_ext_attr(attr);
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return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var));
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}
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EXPORT_SYMBOL_GPL(sysdev_show_ulong);
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ssize_t sysdev_store_int(struct sys_device *sysdev,
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struct sysdev_attribute *attr,
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const char *buf, size_t size)
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|
{
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struct sysdev_ext_attribute *ea = to_ext_attr(attr);
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char *end;
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long new = simple_strtol(buf, &end, 0);
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if (end == buf || new > INT_MAX || new < INT_MIN)
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return -EINVAL;
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*(int *)(ea->var) = new;
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/* Always return full write size even if we didn't consume all */
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|
return size;
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|
}
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EXPORT_SYMBOL_GPL(sysdev_store_int);
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|
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ssize_t sysdev_show_int(struct sys_device *sysdev,
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|
struct sysdev_attribute *attr,
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|
char *buf)
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|
{
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|
struct sysdev_ext_attribute *ea = to_ext_attr(attr);
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|
return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var));
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|
}
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|
EXPORT_SYMBOL_GPL(sysdev_show_int);
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|
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