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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/driver.c
downloadlinux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.bz2
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/driver.c')
-rw-r--r--drivers/base/driver.c138
1 files changed, 138 insertions, 0 deletions
diff --git a/drivers/base/driver.c b/drivers/base/driver.c
new file mode 100644
index 000000000000..3b269f7e5213
--- /dev/null
+++ b/drivers/base/driver.c
@@ -0,0 +1,138 @@
+/*
+ * driver.c - centralized device driver management
+ *
+ * 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/module.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include "base.h"
+
+#define to_dev(node) container_of(node, struct device, driver_list)
+#define to_drv(obj) container_of(obj, struct device_driver, kobj)
+
+/**
+ * driver_create_file - create sysfs file for driver.
+ * @drv: driver.
+ * @attr: driver attribute descriptor.
+ */
+
+int driver_create_file(struct device_driver * drv, struct driver_attribute * attr)
+{
+ int error;
+ if (get_driver(drv)) {
+ error = sysfs_create_file(&drv->kobj, &attr->attr);
+ put_driver(drv);
+ } else
+ error = -EINVAL;
+ return error;
+}
+
+
+/**
+ * driver_remove_file - remove sysfs file for driver.
+ * @drv: driver.
+ * @attr: driver attribute descriptor.
+ */
+
+void driver_remove_file(struct device_driver * drv, struct driver_attribute * attr)
+{
+ if (get_driver(drv)) {
+ sysfs_remove_file(&drv->kobj, &attr->attr);
+ put_driver(drv);
+ }
+}
+
+
+/**
+ * get_driver - increment driver reference count.
+ * @drv: driver.
+ */
+struct device_driver * get_driver(struct device_driver * drv)
+{
+ return drv ? to_drv(kobject_get(&drv->kobj)) : NULL;
+}
+
+
+/**
+ * put_driver - decrement driver's refcount.
+ * @drv: driver.
+ */
+void put_driver(struct device_driver * drv)
+{
+ kobject_put(&drv->kobj);
+}
+
+
+/**
+ * driver_register - register driver with bus
+ * @drv: driver to register
+ *
+ * We pass off most of the work to the bus_add_driver() call,
+ * since most of the things we have to do deal with the bus
+ * structures.
+ *
+ * The one interesting aspect is that we setup @drv->unloaded
+ * as a completion that gets complete when the driver reference
+ * count reaches 0.
+ */
+int driver_register(struct device_driver * drv)
+{
+ INIT_LIST_HEAD(&drv->devices);
+ init_completion(&drv->unloaded);
+ return bus_add_driver(drv);
+}
+
+
+/**
+ * driver_unregister - remove driver from system.
+ * @drv: driver.
+ *
+ * Again, we pass off most of the work to the bus-level call.
+ *
+ * Though, once that is done, we wait until @drv->unloaded is completed.
+ * This will block until the driver refcount reaches 0, and it is
+ * released. Only modular drivers will call this function, and we
+ * have to guarantee that it won't complete, letting the driver
+ * unload until all references are gone.
+ */
+
+void driver_unregister(struct device_driver * drv)
+{
+ bus_remove_driver(drv);
+ wait_for_completion(&drv->unloaded);
+}
+
+/**
+ * driver_find - locate driver on a bus by its name.
+ * @name: name of the driver.
+ * @bus: bus to scan for the driver.
+ *
+ * Call kset_find_obj() to iterate over list of drivers on
+ * a bus to find driver by name. Return driver if found.
+ *
+ * Note that kset_find_obj increments driver's reference count.
+ */
+struct device_driver *driver_find(const char *name, struct bus_type *bus)
+{
+ struct kobject *k = kset_find_obj(&bus->drivers, name);
+ if (k)
+ return to_drv(k);
+ return NULL;
+}
+
+EXPORT_SYMBOL_GPL(driver_register);
+EXPORT_SYMBOL_GPL(driver_unregister);
+EXPORT_SYMBOL_GPL(get_driver);
+EXPORT_SYMBOL_GPL(put_driver);
+EXPORT_SYMBOL_GPL(driver_find);
+
+EXPORT_SYMBOL_GPL(driver_create_file);
+EXPORT_SYMBOL_GPL(driver_remove_file);