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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/base/core.c
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Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/base/core.c')
-rw-r--r--drivers/base/core.c439
1 files changed, 439 insertions, 0 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c
new file mode 100644
index 000000000000..4e6cce8e6d35
--- /dev/null
+++ b/drivers/base/core.c
@@ -0,0 +1,439 @@
+/*
+ * drivers/base/core.c - core driver model code (device registration, etc)
+ *
+ * Copyright (c) 2002-3 Patrick Mochel
+ * Copyright (c) 2002-3 Open Source Development Labs
+ *
+ * This file is released under the GPLv2
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+
+#include <asm/semaphore.h>
+
+#include "base.h"
+#include "power/power.h"
+
+int (*platform_notify)(struct device * dev) = NULL;
+int (*platform_notify_remove)(struct device * dev) = NULL;
+
+/*
+ * sysfs bindings for devices.
+ */
+
+#define to_dev(obj) container_of(obj, struct device, kobj)
+#define to_dev_attr(_attr) container_of(_attr, struct device_attribute, attr)
+
+extern struct attribute * dev_default_attrs[];
+
+static ssize_t
+dev_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
+{
+ struct device_attribute * dev_attr = to_dev_attr(attr);
+ struct device * dev = to_dev(kobj);
+ ssize_t ret = 0;
+
+ if (dev_attr->show)
+ ret = dev_attr->show(dev, buf);
+ return ret;
+}
+
+static ssize_t
+dev_attr_store(struct kobject * kobj, struct attribute * attr,
+ const char * buf, size_t count)
+{
+ struct device_attribute * dev_attr = to_dev_attr(attr);
+ struct device * dev = to_dev(kobj);
+ ssize_t ret = 0;
+
+ if (dev_attr->store)
+ ret = dev_attr->store(dev, buf, count);
+ return ret;
+}
+
+static struct sysfs_ops dev_sysfs_ops = {
+ .show = dev_attr_show,
+ .store = dev_attr_store,
+};
+
+
+/**
+ * device_release - free device structure.
+ * @kobj: device's kobject.
+ *
+ * This is called once the reference count for the object
+ * reaches 0. We forward the call to the device's release
+ * method, which should handle actually freeing the structure.
+ */
+static void device_release(struct kobject * kobj)
+{
+ struct device * dev = to_dev(kobj);
+
+ if (dev->release)
+ dev->release(dev);
+ else {
+ printk(KERN_ERR "Device '%s' does not have a release() function, "
+ "it is broken and must be fixed.\n",
+ dev->bus_id);
+ WARN_ON(1);
+ }
+}
+
+static struct kobj_type ktype_device = {
+ .release = device_release,
+ .sysfs_ops = &dev_sysfs_ops,
+ .default_attrs = dev_default_attrs,
+};
+
+
+static int dev_hotplug_filter(struct kset *kset, struct kobject *kobj)
+{
+ struct kobj_type *ktype = get_ktype(kobj);
+
+ if (ktype == &ktype_device) {
+ struct device *dev = to_dev(kobj);
+ if (dev->bus)
+ return 1;
+ }
+ return 0;
+}
+
+static char *dev_hotplug_name(struct kset *kset, struct kobject *kobj)
+{
+ struct device *dev = to_dev(kobj);
+
+ return dev->bus->name;
+}
+
+static int dev_hotplug(struct kset *kset, struct kobject *kobj, char **envp,
+ int num_envp, char *buffer, int buffer_size)
+{
+ struct device *dev = to_dev(kobj);
+ int i = 0;
+ int length = 0;
+ int retval = 0;
+
+ /* add bus name of physical device */
+ if (dev->bus)
+ add_hotplug_env_var(envp, num_envp, &i,
+ buffer, buffer_size, &length,
+ "PHYSDEVBUS=%s", dev->bus->name);
+
+ /* add driver name of physical device */
+ if (dev->driver)
+ add_hotplug_env_var(envp, num_envp, &i,
+ buffer, buffer_size, &length,
+ "PHYSDEVDRIVER=%s", dev->driver->name);
+
+ /* terminate, set to next free slot, shrink available space */
+ envp[i] = NULL;
+ envp = &envp[i];
+ num_envp -= i;
+ buffer = &buffer[length];
+ buffer_size -= length;
+
+ if (dev->bus->hotplug) {
+ /* have the bus specific function add its stuff */
+ retval = dev->bus->hotplug (dev, envp, num_envp, buffer, buffer_size);
+ if (retval) {
+ pr_debug ("%s - hotplug() returned %d\n",
+ __FUNCTION__, retval);
+ }
+ }
+
+ return retval;
+}
+
+static struct kset_hotplug_ops device_hotplug_ops = {
+ .filter = dev_hotplug_filter,
+ .name = dev_hotplug_name,
+ .hotplug = dev_hotplug,
+};
+
+/**
+ * device_subsys - structure to be registered with kobject core.
+ */
+
+decl_subsys(devices, &ktype_device, &device_hotplug_ops);
+
+
+/**
+ * device_create_file - create sysfs attribute file for device.
+ * @dev: device.
+ * @attr: device attribute descriptor.
+ */
+
+int device_create_file(struct device * dev, struct device_attribute * attr)
+{
+ int error = 0;
+ if (get_device(dev)) {
+ error = sysfs_create_file(&dev->kobj, &attr->attr);
+ put_device(dev);
+ }
+ return error;
+}
+
+/**
+ * device_remove_file - remove sysfs attribute file.
+ * @dev: device.
+ * @attr: device attribute descriptor.
+ */
+
+void device_remove_file(struct device * dev, struct device_attribute * attr)
+{
+ if (get_device(dev)) {
+ sysfs_remove_file(&dev->kobj, &attr->attr);
+ put_device(dev);
+ }
+}
+
+
+/**
+ * device_initialize - init device structure.
+ * @dev: device.
+ *
+ * This prepares the device for use by other layers,
+ * including adding it to the device hierarchy.
+ * It is the first half of device_register(), if called by
+ * that, though it can also be called separately, so one
+ * may use @dev's fields (e.g. the refcount).
+ */
+
+void device_initialize(struct device *dev)
+{
+ kobj_set_kset_s(dev, devices_subsys);
+ kobject_init(&dev->kobj);
+ INIT_LIST_HEAD(&dev->node);
+ INIT_LIST_HEAD(&dev->children);
+ INIT_LIST_HEAD(&dev->driver_list);
+ INIT_LIST_HEAD(&dev->bus_list);
+ INIT_LIST_HEAD(&dev->dma_pools);
+}
+
+/**
+ * device_add - add device to device hierarchy.
+ * @dev: device.
+ *
+ * This is part 2 of device_register(), though may be called
+ * separately _iff_ device_initialize() has been called separately.
+ *
+ * This adds it to the kobject hierarchy via kobject_add(), adds it
+ * to the global and sibling lists for the device, then
+ * adds it to the other relevant subsystems of the driver model.
+ */
+int device_add(struct device *dev)
+{
+ struct device *parent = NULL;
+ int error = -EINVAL;
+
+ dev = get_device(dev);
+ if (!dev || !strlen(dev->bus_id))
+ goto Error;
+
+ parent = get_device(dev->parent);
+
+ pr_debug("DEV: registering device: ID = '%s'\n", dev->bus_id);
+
+ /* first, register with generic layer. */
+ kobject_set_name(&dev->kobj, "%s", dev->bus_id);
+ if (parent)
+ dev->kobj.parent = &parent->kobj;
+
+ if ((error = kobject_add(&dev->kobj)))
+ goto Error;
+ if ((error = device_pm_add(dev)))
+ goto PMError;
+ if ((error = bus_add_device(dev)))
+ goto BusError;
+ down_write(&devices_subsys.rwsem);
+ if (parent)
+ list_add_tail(&dev->node, &parent->children);
+ up_write(&devices_subsys.rwsem);
+
+ /* notify platform of device entry */
+ if (platform_notify)
+ platform_notify(dev);
+ Done:
+ put_device(dev);
+ return error;
+ BusError:
+ device_pm_remove(dev);
+ PMError:
+ kobject_del(&dev->kobj);
+ Error:
+ if (parent)
+ put_device(parent);
+ goto Done;
+}
+
+
+/**
+ * device_register - register a device with the system.
+ * @dev: pointer to the device structure
+ *
+ * This happens in two clean steps - initialize the device
+ * and add it to the system. The two steps can be called
+ * separately, but this is the easiest and most common.
+ * I.e. you should only call the two helpers separately if
+ * have a clearly defined need to use and refcount the device
+ * before it is added to the hierarchy.
+ */
+
+int device_register(struct device *dev)
+{
+ device_initialize(dev);
+ return device_add(dev);
+}
+
+
+/**
+ * get_device - increment reference count for device.
+ * @dev: device.
+ *
+ * This simply forwards the call to kobject_get(), though
+ * we do take care to provide for the case that we get a NULL
+ * pointer passed in.
+ */
+
+struct device * get_device(struct device * dev)
+{
+ return dev ? to_dev(kobject_get(&dev->kobj)) : NULL;
+}
+
+
+/**
+ * put_device - decrement reference count.
+ * @dev: device in question.
+ */
+void put_device(struct device * dev)
+{
+ if (dev)
+ kobject_put(&dev->kobj);
+}
+
+
+/**
+ * device_del - delete device from system.
+ * @dev: device.
+ *
+ * This is the first part of the device unregistration
+ * sequence. This removes the device from the lists we control
+ * from here, has it removed from the other driver model
+ * subsystems it was added to in device_add(), and removes it
+ * from the kobject hierarchy.
+ *
+ * NOTE: this should be called manually _iff_ device_add() was
+ * also called manually.
+ */
+
+void device_del(struct device * dev)
+{
+ struct device * parent = dev->parent;
+
+ down_write(&devices_subsys.rwsem);
+ if (parent)
+ list_del_init(&dev->node);
+ up_write(&devices_subsys.rwsem);
+
+ /* Notify the platform of the removal, in case they
+ * need to do anything...
+ */
+ if (platform_notify_remove)
+ platform_notify_remove(dev);
+ bus_remove_device(dev);
+ device_pm_remove(dev);
+ kobject_del(&dev->kobj);
+ if (parent)
+ put_device(parent);
+}
+
+/**
+ * device_unregister - unregister device from system.
+ * @dev: device going away.
+ *
+ * We do this in two parts, like we do device_register(). First,
+ * we remove it from all the subsystems with device_del(), then
+ * we decrement the reference count via put_device(). If that
+ * is the final reference count, the device will be cleaned up
+ * via device_release() above. Otherwise, the structure will
+ * stick around until the final reference to the device is dropped.
+ */
+void device_unregister(struct device * dev)
+{
+ pr_debug("DEV: Unregistering device. ID = '%s'\n", dev->bus_id);
+ device_del(dev);
+ put_device(dev);
+}
+
+
+/**
+ * device_for_each_child - device child iterator.
+ * @dev: parent struct device.
+ * @data: data for the callback.
+ * @fn: function to be called for each device.
+ *
+ * Iterate over @dev's child devices, and call @fn for each,
+ * passing it @data.
+ *
+ * We check the return of @fn each time. If it returns anything
+ * other than 0, we break out and return that value.
+ */
+int device_for_each_child(struct device * dev, void * data,
+ int (*fn)(struct device *, void *))
+{
+ struct device * child;
+ int error = 0;
+
+ down_read(&devices_subsys.rwsem);
+ list_for_each_entry(child, &dev->children, node) {
+ if((error = fn(child, data)))
+ break;
+ }
+ up_read(&devices_subsys.rwsem);
+ return error;
+}
+
+/**
+ * device_find - locate device on a bus by name.
+ * @name: name of the device.
+ * @bus: bus to scan for the device.
+ *
+ * Call kset_find_obj() to iterate over list of devices on
+ * a bus to find device by name. Return device if found.
+ *
+ * Note that kset_find_obj increments device's reference count.
+ */
+struct device *device_find(const char *name, struct bus_type *bus)
+{
+ struct kobject *k = kset_find_obj(&bus->devices, name);
+ if (k)
+ return to_dev(k);
+ return NULL;
+}
+
+int __init devices_init(void)
+{
+ return subsystem_register(&devices_subsys);
+}
+
+EXPORT_SYMBOL_GPL(device_for_each_child);
+
+EXPORT_SYMBOL_GPL(device_initialize);
+EXPORT_SYMBOL_GPL(device_add);
+EXPORT_SYMBOL_GPL(device_register);
+
+EXPORT_SYMBOL_GPL(device_del);
+EXPORT_SYMBOL_GPL(device_unregister);
+EXPORT_SYMBOL_GPL(get_device);
+EXPORT_SYMBOL_GPL(put_device);
+EXPORT_SYMBOL_GPL(device_find);
+
+EXPORT_SYMBOL_GPL(device_create_file);
+EXPORT_SYMBOL_GPL(device_remove_file);