uclass.h
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/*
* Copyright (c) 2013 Google, Inc
*
* (C) Copyright 2012
* Pavel Herrmann <morpheus.ibis@gmail.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#ifndef _DM_UCLASS_H
#define _DM_UCLASS_H
#include <dm/uclass-id.h>
#include <linux/list.h>
/**
* struct uclass - a U-Boot drive class, collecting together similar drivers
*
* A uclass provides an interface to a particular function, which is
* implemented by one or more drivers. Every driver belongs to a uclass even
* if it is the only driver in that uclass. An example uclass is GPIO, which
* provides the ability to change read inputs, set and clear outputs, etc.
* There may be drivers for on-chip SoC GPIO banks, I2C GPIO expanders and
* PMIC IO lines, all made available in a unified way through the uclass.
*
* @priv: Private data for this uclass
* @uc_drv: The driver for the uclass itself, not to be confused with a
* 'struct driver'
* dev_head: List of devices in this uclass (devices are attached to their
* uclass when their bind method is called)
* @sibling_node: Next uclass in the linked list of uclasses
*/
struct uclass {
void *priv;
struct uclass_driver *uc_drv;
struct list_head dev_head;
struct list_head sibling_node;
};
struct udevice;
/**
* struct uclass_driver - Driver for the uclass
*
* A uclass_driver provides a consistent interface to a set of related
* drivers.
*
* @name: Name of uclass driver
* @id: ID number of this uclass
* @post_bind: Called after a new device is bound to this uclass
* @pre_unbind: Called before a device is unbound from this uclass
* @post_probe: Called after a new device is probed
* @pre_remove: Called before a device is removed
* @init: Called to set up the uclass
* @destroy: Called to destroy the uclass
* @priv_auto_alloc_size: If non-zero this is the size of the private data
* to be allocated in the uclass's ->priv pointer. If zero, then the uclass
* driver is responsible for allocating any data required.
* @per_device_auto_alloc_size: Each device can hold private data owned
* by the uclass. If required this will be automatically allocated if this
* value is non-zero.
* @ops: Uclass operations, providing the consistent interface to devices
* within the uclass.
*/
struct uclass_driver {
const char *name;
enum uclass_id id;
int (*post_bind)(struct udevice *dev);
int (*pre_unbind)(struct udevice *dev);
int (*post_probe)(struct udevice *dev);
int (*pre_remove)(struct udevice *dev);
int (*init)(struct uclass *class);
int (*destroy)(struct uclass *class);
int priv_auto_alloc_size;
int per_device_auto_alloc_size;
const void *ops;
};
/* Declare a new uclass_driver */
#define UCLASS_DRIVER(__name) \
ll_entry_declare(struct uclass_driver, __name, uclass)
/**
* uclass_get() - Get a uclass based on an ID, creating it if needed
*
* Every uclass is identified by an ID, a number from 0 to n-1 where n is
* the number of uclasses. This function allows looking up a uclass by its
* ID.
*
* @key: ID to look up
* @ucp: Returns pointer to uclass (there is only one per ID)
* @return 0 if OK, -ve on error
*/
int uclass_get(enum uclass_id key, struct uclass **ucp);
/**
* uclass_get_device() - Get a uclass device based on an ID and index
*
* id: ID to look up
* @index: Device number within that uclass (0=first)
* @ucp: Returns pointer to uclass (there is only one per for each ID)
* @return 0 if OK, -ve on error
*/
int uclass_get_device(enum uclass_id id, int index, struct udevice **ucp);
/**
* uclass_first_device() - Get the first device in a uclass
*
* @id: Uclass ID to look up
* @devp: Returns pointer to the first device in that uclass, or NULL if none
* @return 0 if OK (found or not found), -1 on error
*/
int uclass_first_device(enum uclass_id id, struct udevice **devp);
/**
* uclass_next_device() - Get the next device in a uclass
*
* @devp: On entry, pointer to device to lookup. On exit, returns pointer
* to the next device in the same uclass, or NULL if none
* @return 0 if OK (found or not found), -1 on error
*/
int uclass_next_device(struct udevice **devp);
/**
* uclass_foreach_dev() - Helper function to iteration through devices
*
* This creates a for() loop which works through the available devices in
* a uclass in order from start to end.
*
* @pos: struct udevice * to hold the current device. Set to NULL when there
* are no more devices.
* uc: uclass to scan
*/
#define uclass_foreach_dev(pos, uc) \
for (pos = list_entry((&(uc)->dev_head)->next, typeof(*pos), \
uclass_node); \
prefetch(pos->uclass_node.next), \
&pos->uclass_node != (&(uc)->dev_head); \
pos = list_entry(pos->uclass_node.next, typeof(*pos), \
uclass_node))
#endif