/*
* sys.c - pseudo-bus for system 'devices' (cpus, PICs, timers, etc)
*
* Copyright (c) 2002-3 Patrick Mochel
* 2002-3 Open Source Development Lab
*
* This file is released under the GPLv2
*
* This exports a 'system' bus type.
* By default, a 'sys' bus gets added to the root of the system. There will
* always be core system devices. Devices can use sysdev_register() to
* add themselves as children of the system bus.
*/
#include <linux/config.h>
#include <linux/sysdev.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/pm.h>
#include <asm/semaphore.h>
extern struct subsystem devices_subsys;
#define to_sysdev(k) container_of(k, struct sys_device, kobj)
#define to_sysdev_attr(a) container_of(a, struct sysdev_attribute, attr)
static ssize_t
sysdev_show(struct kobject * kobj, struct attribute * attr, char * buffer)
{
struct sys_device * sysdev = to_sysdev(kobj);
struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr);
if (sysdev_attr->show)
return sysdev_attr->show(sysdev, buffer);
return -EIO;
}
static ssize_t
sysdev_store(struct kobject * kobj, struct attribute * attr,
const char * buffer, size_t count)
{
struct sys_device * sysdev = to_sysdev(kobj);
struct sysdev_attribute * sysdev_attr = to_sysdev_attr(attr);
if (sysdev_attr->store)
return sysdev_attr->store(sysdev, buffer, count);
return -EIO;
}
static struct sysfs_ops sysfs_ops = {
.show = sysdev_show,
.store = sysdev_store,
};
static struct kobj_type ktype_sysdev = {
.sysfs_ops = &sysfs_ops,
};
int sysdev_create_file(struct sys_device * s, struct sysdev_attribute * a)
{
return sysfs_create_file(&s->kobj, &a->attr);
}
void sysdev_remove_file(struct sys_device * s, struct sysdev_attribute * a)
{
sysfs_remove_file(&s->kobj, &a->attr);
}
EXPORT_SYMBOL_GPL(sysdev_create_file);
EXPORT_SYMBOL_GPL(sysdev_remove_file);
/*
* declare system_subsys
*/
static decl_subsys(system, &ktype_sysdev, NULL);
int sysdev_class_register(struct sysdev_class * cls)
{
pr_debug("Registering sysdev class '%s'\n",
kobject_name(&cls->kset.kobj));
INIT_LIST_HEAD(&cls->drivers);
cls->kset.subsys = &system_subsys;
kset_set_kset_s(cls, system_subsys);
return kset_register(&cls->kset);
}
void sysdev_class_unregister(struct sysdev_class * cls)
{
pr_debug("Unregistering sysdev class '%s'\n",
kobject_name(&cls->kset.kobj));
kset_unregister(&cls->kset);
}
EXPORT_SYMBOL_GPL(sysdev_class_register);
EXPORT_SYMBOL_GPL(sysdev_class_unregister);
static LIST_HEAD(sysdev_drivers);
static DECLARE_MUTEX(sysdev_drivers_lock);
/**
* sysdev_driver_register - Register auxillary driver
* @cls: Device class driver belongs to.
* @drv: Driver.
*
* If @cls is valid, then @drv is inserted into @cls->drivers to be
* called on each operation on devices of that class. The refcount
* of @cls is incremented.
* Otherwise, @drv is inserted into sysdev_drivers, and called for
* each device.
*/
int sysdev_driver_register(struct sysdev_class * cls,
struct sysdev_driver * drv)
{
down(&sysdev_drivers_lock);
if (cls && kset_get(&cls->kset)) {
list_add_tail(&drv->entry, &cls->drivers);
/* If devices of this class already exist, tell the driver */
if (drv->add) {
struct sys_device *dev;
list_for_each_entry(dev, &cls->kset.list, kobj.entry)
drv->add(dev);
}
} else
list_add_tail(&drv->entry, &sysdev_drivers);
up(&sysdev_drivers_lock);
return 0;
}
/**
* sysdev_driver_unregister - Remove an auxillary driver.
* @cls: Class driver belongs to.
* @drv: Driver.
*/
void sysdev_driver_unregister(struct sysdev_class * cls,
struct sysdev_driver * drv)
{
down(&sysdev_drivers_lock);
list_del_init(&drv->entry);
if (cls) {
if (drv->remove) {
struct sys_device *dev;
list_for_each_entry(dev, &cls->kset.list, kobj.entry)
drv->remove(dev);
}
kset_put(&cls->kset);
}
up(&sysdev_drivers_lock);
}
EXPORT_SYMBOL_GPL(sysdev_driver_register);
EXPORT_SYMBOL_GPL(sysdev_driver_unregister);
/**
* sysdev_register - add a system device to the tree
* @sysdev: device in question
*
*/
int sysdev_register(struct sys_device * sysdev)
{
int error;
struct sysdev_class * cls = sysdev->cls;
if (!cls)
return -EINVAL;
/* Make sure the kset is set */
sysdev->kobj.kset = &cls->kset;
/* But make sure we point to the right type for sysfs translation */
sysdev->kobj.ktype = &ktype_sysdev;
error = kobject_set_name(&sysdev->kobj, "%s%d",
kobject_name(&cls->kset.kobj), sysdev->id);
if (error)
return error;
pr_debug("Registering sys device '%s'\n", kobject_name(&sysdev->kobj));
/* Register the object */
error = kobject_register(&sysdev->kobj);
if (!error) {
struct sysdev_driver * drv;
down(&sysdev_drivers_lock);
/* Generic notification is implicit, because it's that
* code that should have called us.
*/
/* Notify global drivers */
list_for_each_entry(drv, &sysdev_drivers, entry) {
if (drv->add)
drv->add(sysdev);
}
/* Notify class auxillary drivers */
list_for_each_entry(drv, &cls->drivers, entry) {
if (drv->add)
drv->add(sysdev);
}
up(&sysdev_drivers_lock);
}
return error;
}
void sysdev_unregister(struct sys_device * sysdev)
{
struct sysdev_driver * drv;
down(&sysdev_drivers_lock);
list_for_each_entry(drv, &sysdev_drivers, entry) {
if (drv->remove)
drv->remove(sysdev);
}
list_for_each_entry(drv, &sysdev->cls->drivers, entry) {
if (drv->remove)
drv->remove(sysdev);
}
up(&sysdev_drivers_lock);
kobject_unregister(&sysdev->kobj);
}
/**
* sysdev_shutdown - Shut down all system devices.
*
* Loop over each class of system devices, and the devices in each
* of those classes. For each device, we call the shutdown method for
* each driver registered for the device - the globals, the auxillaries,
* and the class driver.
*
* Note: The list is iterated in reverse order, so that we shut down
* child devices before we shut down thier parents. The list ordering
* is guaranteed by virtue of the fact that child devices are registered
* after their parents.
*/
void sysdev_shutdown(void)
{
struct sysdev_class * cls;
pr_debug("Shutting Down System Devices\n");
down(&sysdev_drivers_lock);
list_for_each_entry_reverse(cls, &system_subsys.kset.list,
kset.kobj.entry) {
struct sys_device * sysdev;
pr_debug("Shutting down type '%s':\n",
kobject_name(&cls->kset.kobj));
list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
struct sysdev_driver * drv;
pr_debug(" %s\n", kobject_name(&sysdev->kobj));
/* Call global drivers first. */
list_for_each_entry(drv, &sysdev_drivers, entry) {
if (drv->shutdown)
drv->shutdown(sysdev);
}
/* Call auxillary drivers next. */
list_for_each_entry(drv, &cls->drivers, entry) {
if (drv->shutdown)
drv->shutdown(sysdev);
}
/* Now call the generic one */
if (cls->shutdown)
cls->shutdown(sysdev);
}
}
up(&sysdev_drivers_lock);
}
static void __sysdev_resume(struct sys_device *dev)
{
struct sysdev_class *cls = dev->cls;
struct sysdev_driver *drv;
/* First, call the class-specific one */
if (cls->resume)
cls->resume(dev);
/* Call auxillary drivers next. */
list_for_each_entry(drv, &cls->drivers, entry) {
if (drv->resume)
drv->resume(dev);
}
/* Call global drivers. */
list_for_each_entry(drv, &sysdev_drivers, entry) {
if (drv->resume)
drv->resume(dev);
}
}
/**
* sysdev_suspend - Suspend all system devices.
* @state: Power state to enter.
*
* We perform an almost identical operation as sys_device_shutdown()
* above, though calling ->suspend() instead. Interrupts are disabled
* when this called. Devices are responsible for both saving state and
* quiescing or powering down the device.
*
* This is only called by the device PM core, so we let them handle
* all synchronization.
*/
int sysdev_suspend(pm_message_t state)
{
struct sysdev_class * cls;
struct sys_device *sysdev, *err_dev;
struct sysdev_driver *drv, *err_drv;
int ret;
pr_debug("Suspending System Devices\n");
list_for_each_entry_reverse(cls, &system_subsys.kset.list,
kset.kobj.entry) {
pr_debug("Suspending type '%s':\n",
kobject_name(&cls->kset.kobj));
list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
pr_debug(" %s\n", kobject_name(&sysdev->kobj));
/* Call global drivers first. */
list_for_each_entry(drv, &sysdev_drivers, entry) {
if (drv->suspend) {
ret = drv->suspend(sysdev, state);
if (ret)
goto gbl_driver;
}
}
/* Call auxillary drivers next. */
list_for_each_entry(drv, &cls->drivers, entry) {
if (drv->suspend) {
ret = drv->suspend(sysdev, state);
if (ret)
goto aux_driver;
}
}
/* Now call the generic one */
if (cls->suspend) {
ret = cls->suspend(sysdev, state);
if (ret)
goto cls_driver;
}
}
}
return 0;
/* resume current sysdev */
cls_driver:
drv = NULL;
printk(KERN_ERR "Class suspend failed for %s\n",
kobject_name(&sysdev->kobj));
aux_driver:
if (drv)
printk(KERN_ERR "Class driver suspend failed for %s\n",
kobject_name(&sysdev->kobj));
list_for_each_entry(err_drv, &cls->drivers, entry) {
if (err_drv == drv)
break;
if (err_drv->resume)
err_drv->resume(sysdev);
}
drv = NULL;
gbl_driver:
if (drv)
printk(KERN_ERR "sysdev driver suspend failed for %s\n",
kobject_name(&sysdev->kobj));
list_for_each_entry(err_drv, &sysdev_drivers, entry) {
if (err_drv == drv)
break;
if (err_drv->resume)
err_drv->resume(sysdev);
}
/* resume other sysdevs in current class */
list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) {
if (err_dev == sysdev)
break;
pr_debug(" %s\n", kobject_name(&err_dev->kobj));
__sysdev_resume(err_dev);
}
/* resume other classes */
list_for_each_entry_continue(cls, &system_subsys.kset.list,
kset.kobj.entry) {
list_for_each_entry(err_dev, &cls->kset.list, kobj.entry) {
pr_debug(" %s\n", kobject_name(&err_dev->kobj));
__sysdev_resume(err_dev);
}
}
return ret;
}
/**
* sysdev_resume - Bring system devices back to life.
*
* Similar to sys_device_suspend(), but we iterate the list forwards
* to guarantee that parent devices are resumed before their children.
*
* Note: Interrupts are disabled when called.
*/
int sysdev_resume(void)
{
struct sysdev_class * cls;
pr_debug("Resuming System Devices\n");
list_for_each_entry(cls, &system_subsys.kset.list, kset.kobj.entry) {
struct sys_device * sysdev;
pr_debug("Resuming type '%s':\n",
kobject_name(&cls->kset.kobj));
list_for_each_entry(sysdev, &cls->kset.list, kobj.entry) {
pr_debug(" %s\n", kobject_name(&sysdev->kobj));
__sysdev_resume(sysdev);
}
}
return 0;
}
int __init system_bus_init(void)
{
system_subsys.kset.kobj.parent = &devices_subsys.kset.kobj;
return subsystem_register(&system_subsys);
}
EXPORT_SYMBOL_GPL(sysdev_register);
EXPORT_SYMBOL_GPL(sysdev_unregister);
