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