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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 22:20:36 (GMT) |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/base/core.c | |
download | linux-fsl-qoriq-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.xz |
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!
Diffstat (limited to 'drivers/base/core.c')
-rw-r--r-- | drivers/base/core.c | 439 |
1 files changed, 439 insertions, 0 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c new file mode 100644 index 0000000..4e6cce8 --- /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); |