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227 lines
5.8 KiB
227 lines
5.8 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* driver.c - centralized device driver management |
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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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* Copyright (c) 2007 Greg Kroah-Hartman <[email protected]> |
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* Copyright (c) 2007 Novell Inc. |
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*/ |
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#include <linux/device/driver.h> |
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#include <linux/device.h> |
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#include <linux/module.h> |
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#include <linux/errno.h> |
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#include <linux/slab.h> |
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#include <linux/string.h> |
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#include <linux/sysfs.h> |
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#include "base.h" |
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static struct device *next_device(struct klist_iter *i) |
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{ |
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struct klist_node *n = klist_next(i); |
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struct device *dev = NULL; |
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struct device_private *dev_prv; |
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if (n) { |
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dev_prv = to_device_private_driver(n); |
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dev = dev_prv->device; |
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} |
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return dev; |
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} |
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/** |
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* driver_for_each_device - Iterator for devices bound to a driver. |
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* @drv: Driver we're iterating. |
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* @start: Device to begin with |
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* @data: Data to pass to the callback. |
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* @fn: Function to call for each device. |
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* |
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* Iterate over the @drv's list of devices calling @fn for each one. |
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*/ |
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int driver_for_each_device(struct device_driver *drv, struct device *start, |
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void *data, int (*fn)(struct device *, void *)) |
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{ |
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struct klist_iter i; |
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struct device *dev; |
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int error = 0; |
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if (!drv) |
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return -EINVAL; |
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klist_iter_init_node(&drv->p->klist_devices, &i, |
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start ? &start->p->knode_driver : NULL); |
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while (!error && (dev = next_device(&i))) |
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error = fn(dev, data); |
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klist_iter_exit(&i); |
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return error; |
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} |
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EXPORT_SYMBOL_GPL(driver_for_each_device); |
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/** |
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* driver_find_device - device iterator for locating a particular device. |
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* @drv: The device's driver |
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* @start: Device to begin with |
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* @data: Data to pass to match function |
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* @match: Callback function to check device |
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* |
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* This is similar to the driver_for_each_device() function above, but |
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* it returns a reference to a device that is 'found' for later use, as |
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* determined by the @match callback. |
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* |
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* The callback should return 0 if the device doesn't match and non-zero |
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* if it does. If the callback returns non-zero, this function will |
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* return to the caller and not iterate over any more devices. |
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*/ |
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struct device *driver_find_device(struct device_driver *drv, |
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struct device *start, const void *data, |
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int (*match)(struct device *dev, const void *data)) |
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{ |
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struct klist_iter i; |
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struct device *dev; |
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if (!drv || !drv->p) |
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return NULL; |
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klist_iter_init_node(&drv->p->klist_devices, &i, |
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(start ? &start->p->knode_driver : NULL)); |
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while ((dev = next_device(&i))) |
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if (match(dev, data) && get_device(dev)) |
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break; |
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klist_iter_exit(&i); |
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return dev; |
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} |
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EXPORT_SYMBOL_GPL(driver_find_device); |
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/** |
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* driver_create_file - create sysfs file for driver. |
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* @drv: driver. |
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* @attr: driver attribute descriptor. |
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*/ |
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int driver_create_file(struct device_driver *drv, |
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const struct driver_attribute *attr) |
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{ |
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int error; |
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if (drv) |
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error = sysfs_create_file(&drv->p->kobj, &attr->attr); |
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else |
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error = -EINVAL; |
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return error; |
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} |
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EXPORT_SYMBOL_GPL(driver_create_file); |
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/** |
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* driver_remove_file - remove sysfs file for driver. |
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* @drv: driver. |
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* @attr: driver attribute descriptor. |
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*/ |
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void driver_remove_file(struct device_driver *drv, |
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const struct driver_attribute *attr) |
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{ |
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if (drv) |
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sysfs_remove_file(&drv->p->kobj, &attr->attr); |
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} |
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EXPORT_SYMBOL_GPL(driver_remove_file); |
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int driver_add_groups(struct device_driver *drv, |
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const struct attribute_group **groups) |
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{ |
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return sysfs_create_groups(&drv->p->kobj, groups); |
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} |
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void driver_remove_groups(struct device_driver *drv, |
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const struct attribute_group **groups) |
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{ |
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sysfs_remove_groups(&drv->p->kobj, groups); |
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} |
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/** |
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* driver_register - register driver with bus |
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* @drv: driver to register |
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* |
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* We pass off most of the work to the bus_add_driver() call, |
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* since most of the things we have to do deal with the bus |
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* structures. |
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*/ |
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int driver_register(struct device_driver *drv) |
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{ |
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int ret; |
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struct device_driver *other; |
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if (!drv->bus->p) { |
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pr_err("Driver '%s' was unable to register with bus_type '%s' because the bus was not initialized.\n", |
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drv->name, drv->bus->name); |
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return -EINVAL; |
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} |
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if ((drv->bus->probe && drv->probe) || |
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(drv->bus->remove && drv->remove) || |
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(drv->bus->shutdown && drv->shutdown)) |
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pr_warn("Driver '%s' needs updating - please use " |
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"bus_type methods\n", drv->name); |
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other = driver_find(drv->name, drv->bus); |
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if (other) { |
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pr_err("Error: Driver '%s' is already registered, " |
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"aborting...\n", drv->name); |
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return -EBUSY; |
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} |
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ret = bus_add_driver(drv); |
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if (ret) |
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return ret; |
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ret = driver_add_groups(drv, drv->groups); |
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if (ret) { |
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bus_remove_driver(drv); |
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return ret; |
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} |
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kobject_uevent(&drv->p->kobj, KOBJ_ADD); |
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return ret; |
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} |
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EXPORT_SYMBOL_GPL(driver_register); |
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/** |
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* driver_unregister - remove driver from system. |
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* @drv: driver. |
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* |
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* Again, we pass off most of the work to the bus-level call. |
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*/ |
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void driver_unregister(struct device_driver *drv) |
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{ |
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if (!drv || !drv->p) { |
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WARN(1, "Unexpected driver unregister!\n"); |
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return; |
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} |
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driver_remove_groups(drv, drv->groups); |
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bus_remove_driver(drv); |
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} |
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EXPORT_SYMBOL_GPL(driver_unregister); |
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/** |
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* driver_find - locate driver on a bus by its name. |
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* @name: name of the driver. |
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* @bus: bus to scan for the driver. |
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* |
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* Call kset_find_obj() to iterate over list of drivers on |
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* a bus to find driver by name. Return driver if found. |
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* |
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* This routine provides no locking to prevent the driver it returns |
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* from being unregistered or unloaded while the caller is using it. |
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* The caller is responsible for preventing this. |
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*/ |
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struct device_driver *driver_find(const char *name, struct bus_type *bus) |
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{ |
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struct kobject *k = kset_find_obj(bus->p->drivers_kset, name); |
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struct driver_private *priv; |
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if (k) { |
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/* Drop reference added by kset_find_obj() */ |
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kobject_put(k); |
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priv = to_driver(k); |
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return priv->driver; |
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} |
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return NULL; |
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} |
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EXPORT_SYMBOL_GPL(driver_find);
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