/*
* 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/sysdev.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/pm.h>
#include <linux/device.h>
#include <linux/mutex.h>
#include <linux/interrupt.h>
#include "base.h"
#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, sysdev_attr, 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, sysdev_attr, buffer, count);
return -EIO;
}
static const 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);
#define to_sysdev_class(k) container_of(k, struct sysdev_class, kset.kobj)
#define to_sysdev_class_attr(a) container_of(a, \
struct sysdev_class_attribute, attr)
static ssize_t sysdev_class_show(struct kobject *kobj, struct attribute *attr,
char *buffer)
{
struct sysdev_class *class = to_sysdev_class(kobj);
struct sysdev_class_attribute *class_attr = to_sysdev_class_attr(attr);
if (class_attr->show)
return class_attr->show(class, class_attr, buffer);
return -EIO;
}
static ssize_t sysdev_class_store(struct kobject *kobj, struct attribute *attr,
const char *buffer, size_t count)
{
struct sysdev_class *class = to_sysdev_class(kobj);
struct sysdev_class_attribute *class_attr = to_sysdev_class_attr(attr);
if (class_attr->store)
return class_attr->store(class, class_attr, buffer, count);
return -EIO;
}
static const struct sysfs_ops sysfs_class_ops = {
.show = sysdev_class_show,
.store = sysdev_class_store,
};
static struct kobj_type ktype_sysdev_class = {
.sysfs_ops = &sysfs_class_ops,
};
int sysdev_class_create_file(struct sysdev_class *c,
struct sysdev_class_attribute *a)
{
return sysfs_create_file(&c->kset.kobj, &a->attr);
}
EXPORT_SYMBOL_GPL(sysdev_class_create_file);
void sysdev_class_remove_file(struct sysdev_class *c,
struct sysdev_class_attribute *a)
{
sysfs_remove_file(&c->kset.kobj, &a->attr);
}
EXPORT_SYMBOL_GPL(sysdev_class_remove_file);
static struct kset *system_kset;
int sysdev_class_register(struct sysdev_class *cls)
{
int retval;
pr_debug("Registering sysdev class '%s'\n", cls->name);
INIT_LIST_HEAD(&cls->drivers);
memset(&cls->kset.kobj, 0x00, sizeof(struct kobject));
cls->kset.kobj.parent = &system_kset->kobj;
cls->kset.kobj.ktype = &ktype_sysdev_class;
cls->kset.kobj.kset = system_kset;
retval = kobject_set_name(&cls->kset.kobj, "%s", cls->name);
if (retval)
return retval;
retval = kset_register(&cls->kset);
if (!retval && cls->attrs)
retval = sysfs_create_files(&cls->kset.kobj,
(const struct attribute **)cls->attrs);
return retval;
}
void sysdev_class_unregister(struct sysdev_class *cls)
{
pr_debug("Unregistering sysdev class '%s'\n",
kobject_name(&cls->kset.kobj));
if (cls->attrs)
sysfs_remove_files(&cls->kset.kobj,
(const struct attribute **)cls->attrs);
kset_unregister(&cls->kset);
}
EXPORT_SYMBOL_GPL(sysdev_class_register);
EXPORT_SYMBOL_GPL(sysdev_class_unregister);
static DEFINE_MUTEX(sysdev_drivers_lock);
/*
* @dev != NULL means that we're unwinding because some drv->add()
* failed for some reason. You need to grab sysdev_drivers_lock before
* calling this.
*/
static void __sysdev_driver_remove(struct sysdev_class *cls,
struct sysdev_driver *drv,
struct sys_device *from_dev)
{
struct sys_device *dev = from_dev;
list_del_init(&drv->entry);
if (!cls)
return;
if (!drv->remove)
goto kset_put;
if (dev)
list_for_each_entry_continue_reverse(dev, &cls->kset.list,
kobj.entry)
drv->remove(dev);
else
list_for_each_entry(dev, &cls->kset.list, kobj.entry)
drv->remove(dev);
kset_put:
kset_put(&cls->kset);
}
/**
* sysdev_driver_register - Register auxillary driver
* @cls: Device class driver belongs to.
* @drv: Driver.
*
* @drv is inserted into @cls->drivers to be
* called on each operation on devices of that class. The refcount
* of @cls is incremented.
*/
int sysdev_driver_register(struct sysdev_class *cls, struct sysdev_driver *drv)
{
struct sys_device *dev = NULL;
int err = 0;
if (!cls) {
WARN(1, KERN_WARNING "sysdev: invalid class passed to %s!\n",
__func__);
return -EINVAL;
}
/* Check whether this driver has already been added to a class. */
if (drv->entry.next && !list_empty(&drv->entry))
WARN(1, KERN_WARNING "sysdev: class %s: driver (%p) has already"
" been registered to a class, something is wrong, but "
"will forge on!\n", cls->name, drv);
mutex_lock(&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) {
list_for_each_entry(dev, &cls->kset.list, kobj.entry) {
err = drv->add(dev);
if (err)
goto unwind;
}
}
} else {
err = -EINVAL;
WARN(1, KERN_ERR "%s: invalid device class\n", __func__);
}
goto unlock;
unwind:
__sysdev_driver_remove(cls, drv, dev);
unlock:
mutex_unlock(&sysdev_drivers_lock);
return err;
}
/**
* 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)
{
mutex_lock(&sysdev_drivers_lock);
__sysdev_driver_remove(cls, drv, NULL);
mutex_unlock(&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;
pr_debug("Registering sys device of class '%s'\n",
kobject_name(&cls->kset.kobj));
/* initialize the kobject to 0, in case it had previously been used */
memset(&sysdev->kobj, 0x00, sizeof(struct kobject));
/* Make sure the kset is set */
sysdev->kobj.kset = &cls->kset;
/* Register the object */
error = kobject_init_and_add(&sysdev->kobj, &ktype_sysdev, NULL,
"%s%d", kobject_name(&cls->kset.kobj),
sysdev->id);
if (!error) {
struct sysdev_driver *drv;
pr_debug("Registering sys device '%s'\n",
kobject_name(&sysdev->kobj));
mutex_lock(&sysdev_drivers_lock);
/* Generic notification is implicit, because it's that
* code that should have called us.
*/
/* Notify class auxillary drivers */
list_for_each_entry(drv, &cls->drivers, entry) {
if (drv->add)
drv->add(sysdev);
}
mutex_unlock(&sysdev_drivers_lock);
kobject_uevent(&sysdev->kobj, KOBJ_ADD);
}
return error;
}
void sysdev_unregister(struct sys_device *sysdev)
{
struct sysdev_driver *drv;
mutex_lock(&sysdev_drivers_lock);
list_for_each_entry(drv, &sysdev->cls->drivers, entry) {
if (drv->remove)
drv->remove(sysdev);
}
mutex_unlock(&sysdev_drivers_lock);
kobject_put(&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 auxillaries,
* and the class driver.
*
* Note: The list is iterated in reverse order, so that we shut down
* child devices before we shut down their 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");
mutex_lock(&sysdev_drivers_lock);
list_for_each_entry_reverse(cls, &system_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 auxillary drivers first */
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);
}
}
mutex_unlock(&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);
WARN_ONCE(!irqs_disabled(),
"Interrupts enabled after %pF\n", cls->resume);
/* Call auxillary drivers next. */
list_for_each_entry(drv, &cls->drivers, entry) {
if (drv->resume)
drv->resume(dev);
WARN_ONCE(!irqs_disabled(),
"Interrupts enabled after %pF\n", drv->resume);
}
}
/**
* sysdev_suspend - Suspend all system devices.
* @state: Power state to enter.
*
* We perform an almost identical operation as sysdev_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("Checking wake-up interrupts\n");
/* Return error code if there are any wake-up interrupts pending */
ret = check_wakeup_irqs();
if (ret)
return ret;
WARN_ONCE(!irqs_disabled(),
"Interrupts enabled while suspending system devices\n");
pr_debug("Suspending System Devices\n");
list_for_each_entry_reverse(cls, &system_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 auxillary drivers first */
list_for_each_entry(drv, &cls->drivers, entry) {
if (drv->suspend) {
ret = drv->suspend(sysdev, state);
if (ret)
goto aux_driver;
}
WARN_ONCE(!irqs_disabled(),
"Interrupts enabled after %pF\n",
drv->suspend);
}
/* Now call the generic one */
if (cls->suspend) {
ret = cls->suspend(sysdev, state);
if (ret)
goto cls_driver;
WARN_ONCE(!irqs_disabled(),
"Interrupts enabled after %pF\n",
cls->suspend);
}
}
}
return 0;
/* resume current sysdev */
cls_driver:
drv = NULL;
printk(KERN_ERR "Class suspend failed for %s: %d\n",
kobject_name(&sysdev->kobj), ret);
aux_driver:
if (drv)
printk(KERN_ERR "Class driver suspend failed for %s: %d\n",
kobject_name(&sysdev->kobj), ret);
list_for_each_entry(err_drv, &cls->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_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;
}
EXPORT_SYMBOL_GPL(sysdev_suspend);
/**
* sysdev_resume - Bring system devices back to life.
*
* Similar to sysdev_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;
WARN_ONCE(!irqs_disabled(),
"Interrupts enabled while resuming system devices\n");
pr_debug("Resuming System Devices\n");
list_for_each_entry(cls, &system_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;
}
EXPORT_SYMBOL_GPL(sysdev_resume);
int __init system_bus_init(void)
{
system_kset = kset_create_and_add("system", NULL, &devices_kset->kobj);
if (!system_kset)
return -ENOMEM;
return 0;
}
EXPORT_SYMBOL_GPL(sysdev_register);
EXPORT_SYMBOL_GPL(sysdev_unregister);
#define to_ext_attr(x) container_of(x, struct sysdev_ext_attribute, attr)
ssize_t sysdev_store_ulong(struct sys_device *sysdev,
struct sysdev_attribute *attr,
const char *buf, size_t size)
{
struct sysdev_ext_attribute *ea = to_ext_attr(attr);
char *end;
unsigned long new = simple_strtoul(buf, &end, 0);
if (end == buf)
return -EINVAL;
*(unsigned long *)(ea->var) = new;
/* Always return full write size even if we didn't consume all */
return size;
}
EXPORT_SYMBOL_GPL(sysdev_store_ulong);
ssize_t sysdev_show_ulong(struct sys_device *sysdev,
struct sysdev_attribute *attr,
char *buf)
{
struct sysdev_ext_attribute *ea = to_ext_attr(attr);
return snprintf(buf, PAGE_SIZE, "%lx\n", *(unsigned long *)(ea->var));
}
EXPORT_SYMBOL_GPL(sysdev_show_ulong);
ssize_t sysdev_store_int(struct sys_device *sysdev,
struct sysdev_attribute *attr,
const char *buf, size_t size)
{
struct sysdev_ext_attribute *ea = to_ext_attr(attr);
char *end;
long new = simple_strtol(buf, &end, 0);
if (end == buf || new > INT_MAX || new < INT_MIN)
return -EINVAL;
*(int *)(ea->var) = new;
/* Always return full write size even if we didn't consume all */
return size;
}
EXPORT_SYMBOL_GPL(sysdev_store_int);
ssize_t sysdev_show_int(struct sys_device *sysdev,
struct sysdev_attribute *attr,
char *buf)
{
struct sysdev_ext_attribute *ea = to_ext_attr(attr);
return snprintf(buf, PAGE_SIZE, "%d\n", *(int *)(ea->var));
}
EXPORT_SYMBOL_GPL(sysdev_show_int);
