linux/drivers/base/driver.c

// SPDX-License-Identifier: GPL-2.0
/*
 * 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 <[email protected]>
 * Copyright (c) 2007 Novell Inc.
 */

#include <linux/device/driver.h>
#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)
{ … }

/**
 * driver_set_override() - Helper to set or clear driver override.
 * @dev: Device to change
 * @override: Address of string to change (e.g. &device->driver_override);
 *            The contents will be freed and hold newly allocated override.
 * @s: NUL-terminated string, new driver name to force a match, pass empty
 *     string to clear it ("" or "\n", where the latter is only for sysfs
 *     interface).
 * @len: length of @s
 *
 * Helper to set or clear driver override in a device, intended for the cases
 * when the driver_override field is allocated by driver/bus code.
 *
 * Returns: 0 on success or a negative error code on failure.
 */
int driver_set_override(struct device *dev, const char **override,
			const char *s, size_t len)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * 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 *))
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * 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(const struct device_driver *drv,
				  struct device *start, const void *data,
				  int (*match)(struct device *dev, const void *data))
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * driver_create_file - create sysfs file for driver.
 * @drv: driver.
 * @attr: driver attribute descriptor.
 */
int driver_create_file(const struct device_driver *drv,
		       const struct driver_attribute *attr)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * driver_remove_file - remove sysfs file for driver.
 * @drv: driver.
 * @attr: driver attribute descriptor.
 */
void driver_remove_file(const struct device_driver *drv,
			const struct driver_attribute *attr)
{ … }
EXPORT_SYMBOL_GPL(…);

int driver_add_groups(const struct device_driver *drv,
		      const struct attribute_group **groups)
{ … }

void driver_remove_groups(const struct device_driver *drv,
			  const struct attribute_group **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)
{ … }
EXPORT_SYMBOL_GPL(…);

/**
 * 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)
{ … }
EXPORT_SYMBOL_GPL(…);