--- /dev/null
+/*
+ * driver.c - centralized device driver management
+ *
+ * Copyright (c) 2002-3 Patrick Mochel
+ * Copyright (c) 2002-3 Open Source Development Labs
+ * Copyright (c) 2007 Greg Kroah-Hartman <gregkh@suse.de>
+ * Copyright (c) 2007 Novell Inc.
+ *
+ * This file is released under the GPLv2
+ *
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/sysfs.h>
+#include "base.h"
+
+static struct device *next_device(struct klist_iter *i)
+{
+ struct klist_node *n = klist_next(i);
+ struct device *dev = NULL;
+ struct device_private *dev_prv;
+
+ if (n) {
+ dev_prv = to_device_private_driver(n);
+ dev = dev_prv->device;
+ }
+ return dev;
+}
+
+/**
+ * driver_for_each_device - Iterator for devices bound to a driver.
+ * @drv: Driver we're iterating.
+ * @start: Device to begin with
+ * @data: Data to pass to the callback.
+ * @fn: Function to call for each device.
+ *
+ * Iterate over the @drv's list of devices calling @fn for each one.
+ */
+int driver_for_each_device(struct device_driver *drv, struct device *start,
+ void *data, int (*fn)(struct device *, void *))
+{
+ struct klist_iter i;
+ struct device *dev;
+ int error = 0;
+
+ if (!drv)
+ return -EINVAL;
+
+ klist_iter_init_node(&drv->p->klist_devices, &i,
+ start ? &start->p->knode_driver : NULL);
+ while ((dev = next_device(&i)) && !error)
+ error = fn(dev, data);
+ klist_iter_exit(&i);
+ return error;
+}
+EXPORT_SYMBOL_GPL(driver_for_each_device);
+
+/**
+ * driver_find_device - device iterator for locating a particular device.
+ * @drv: The device's driver
+ * @start: Device to begin with
+ * @data: Data to pass to match function
+ * @match: Callback function to check device
+ *
+ * This is similar to the driver_for_each_device() function above, but
+ * it returns a reference to a device that is 'found' for later use, as
+ * determined by the @match callback.
+ *
+ * The callback should return 0 if the device doesn't match and non-zero
+ * if it does. If the callback returns non-zero, this function will
+ * return to the caller and not iterate over any more devices.
+ */
+struct device *driver_find_device(struct device_driver *drv,
+ struct device *start, void *data,
+ int (*match)(struct device *dev, void *data))
+{
+ struct klist_iter i;
+ struct device *dev;
+
+ if (!drv || !drv->p)
+ return NULL;
+
+ klist_iter_init_node(&drv->p->klist_devices, &i,
+ (start ? &start->p->knode_driver : NULL));
+ while ((dev = next_device(&i)))
+ if (match(dev, data) && get_device(dev))
+ break;
+ klist_iter_exit(&i);
+ return dev;
+}
+EXPORT_SYMBOL_GPL(driver_find_device);
+
+/**
+ * driver_create_file - create sysfs file for driver.
+ * @drv: driver.
+ * @attr: driver attribute descriptor.
+ */
+int driver_create_file(struct device_driver *drv,
+ const struct driver_attribute *attr)
+{
+ int error;
+
+ if (drv)
+ error = sysfs_create_file(&drv->p->kobj, &attr->attr);
+ else
+ error = -EINVAL;
+ return error;
+}
+EXPORT_SYMBOL_GPL(driver_create_file);
+
+/**
+ * driver_remove_file - remove sysfs file for driver.
+ * @drv: driver.
+ * @attr: driver attribute descriptor.
+ */
+void driver_remove_file(struct device_driver *drv,
+ const struct driver_attribute *attr)
+{
+ if (drv)
+ sysfs_remove_file(&drv->p->kobj, &attr->attr);
+}
+EXPORT_SYMBOL_GPL(driver_remove_file);
+
+int driver_add_groups(struct device_driver *drv,
+ const struct attribute_group **groups)
+{
+ return sysfs_create_groups(&drv->p->kobj, groups);
+}
+
+void driver_remove_groups(struct device_driver *drv,
+ const struct attribute_group **groups)
+{
+ sysfs_remove_groups(&drv->p->kobj, groups);
+}
+
+/**
+ * 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.
+ */
+int driver_register(struct device_driver *drv)
+{
+ int ret;
+ struct device_driver *other;
+
+ BUG_ON(!drv->bus->p);
+
+ if ((drv->bus->probe && drv->probe) ||
+ (drv->bus->remove && drv->remove) ||
+ (drv->bus->shutdown && drv->shutdown))
+ printk(KERN_WARNING "Driver '%s' needs updating - please use "
+ "bus_type methods\n", drv->name);
+
+ other = driver_find(drv->name, drv->bus);
+ if (other) {
+ printk(KERN_ERR "Error: Driver '%s' is already registered, "
+ "aborting...\n", drv->name);
+ return -EBUSY;
+ }
+
+ ret = bus_add_driver(drv);
+ if (ret)
+ return ret;
+ ret = driver_add_groups(drv, drv->groups);
+ if (ret) {
+ bus_remove_driver(drv);
+ return ret;
+ }
+ kobject_uevent(&drv->p->kobj, KOBJ_ADD);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(driver_register);
+
+/**
+ * driver_unregister - remove driver from system.
+ * @drv: driver.
+ *
+ * Again, we pass off most of the work to the bus-level call.
+ */
+void driver_unregister(struct device_driver *drv)
+{
+ if (!drv || !drv->p) {
+ WARN(1, "Unexpected driver unregister!\n");
+ return;
+ }
+ driver_remove_groups(drv, drv->groups);
+ bus_remove_driver(drv);
+}
+EXPORT_SYMBOL_GPL(driver_unregister);
+
+/**
+ * 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.
+ *
+ * This routine provides no locking to prevent the driver it returns
+ * from being unregistered or unloaded while the caller is using it.
+ * The caller is responsible for preventing this.
+ */
+struct device_driver *driver_find(const char *name, struct bus_type *bus)
+{
+ struct kobject *k = kset_find_obj(bus->p->drivers_kset, name);
+ struct driver_private *priv;
+
+ if (k) {
+ /* Drop reference added by kset_find_obj() */
+ kobject_put(k);
+ priv = to_driver(k);
+ return priv->driver;
+ }
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(driver_find);
Code Review / kvmfornfv.git / blobdiff