summaryrefslogtreecommitdiff
path: root/drivers/base/sys.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/base/sys.c')
-rw-r--r--drivers/base/sys.c397
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);