diff options
Diffstat (limited to 'drivers/base/sys.c')
-rw-r--r-- | drivers/base/sys.c | 397 |
1 files changed, 397 insertions, 0 deletions
diff --git a/drivers/base/sys.c b/drivers/base/sys.c new file mode 100644 index 00000000000..cff5a6a2c78 --- /dev/null +++ b/drivers/base/sys.c @@ -0,0 +1,397 @@ +/* + * 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> + + +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 0; +} + + +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 0; +} + +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); +} + + +/** + * 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(u32 state) +{ + struct sysdev_class * cls; + + pr_debug("Suspending System Devices\n"); + + list_for_each_entry_reverse(cls, &system_subsys.kset.list, + kset.kobj.entry) { + struct sys_device * sysdev; + + pr_debug("Suspending 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->suspend) + drv->suspend(sysdev, state); + } + + /* Call auxillary drivers next. */ + list_for_each_entry(drv, &cls->drivers, entry) { + if (drv->suspend) + drv->suspend(sysdev, state); + } + + /* Now call the generic one */ + if (cls->suspend) + cls->suspend(sysdev, state); + } + } + return 0; +} + + +/** + * 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) { + struct sysdev_driver * drv; + pr_debug(" %s\n", kobject_name(&sysdev->kobj)); + + /* First, call the class-specific one */ + if (cls->resume) + cls->resume(sysdev); + + /* Call auxillary drivers next. */ + list_for_each_entry(drv, &cls->drivers, entry) { + if (drv->resume) + drv->resume(sysdev); + } + + /* Call global drivers. */ + list_for_each_entry(drv, &sysdev_drivers, entry) { + if (drv->resume) + drv->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); |