/* * Copyright (c) 2013 Google, Inc * * (C) Copyright 2012 * Pavel Herrmann * * SPDX-License-Identifier: GPL-2.0+ */ #ifndef _DM_UCLASS_H #define _DM_UCLASS_H #include #include #include /** * 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; /* Members of this uclass sequence themselves with aliases */ #define DM_UC_FLAG_SEQ_ALIAS (1 << 0) /** * 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. * @per_child_platdata_auto_alloc_size: A bus likes to store information about * its children. If non-zero this is the size of this data, to be allocated * in the child device's parent_platdata pointer. This value is only used as * a falback if this member is 0 in the driver. * @ops: Uclass operations, providing the consistent interface to devices * within the uclass. * @flags: Flags for this uclass (DM_UC_...) */ 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; int per_child_platdata_auto_alloc_size; const void *ops; uint32_t flags; }; /* 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 * * The device is probed to activate it ready for use. * * @id: ID to look up * @index: Device number within that uclass (0=first) * @devp: Returns pointer to device (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 **devp); /** * uclass_get_device_by_seq() - Get a uclass device based on an ID and sequence * * If an active device has this sequence it will be returned. If there is no * such device then this will check for a device that is requesting this * sequence. * * The device is probed to activate it ready for use. * * @id: ID to look up * @seq: Sequence number to find (0=first) * @devp: Returns pointer to device (there is only one for each seq) * @return 0 if OK, -ve on error */ int uclass_get_device_by_seq(enum uclass_id id, int seq, struct udevice **devp); /** * uclass_get_device_by_of_offset() - Get a uclass device by device tree node * * This searches the devices in the uclass for one attached to the given * device tree node. * * The device is probed to activate it ready for use. * * @id: ID to look up * @node: Device tree offset to search for (if -ve then -ENODEV is returned) * @devp: Returns pointer to device (there is only one for each node) * @return 0 if OK, -ve on error */ int uclass_get_device_by_of_offset(enum uclass_id id, int node, struct udevice **devp); /** * uclass_first_device() - Get the first device in a uclass * * The device returned is probed if necessary, and ready for use * * @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 * * The device returned is probed if necessary, and ready for use * * @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_resolve_seq() - Resolve a device's sequence number * * On entry dev->seq is -1, and dev->req_seq may be -1 (to allocate a * sequence number automatically, or >= 0 to select a particular number. * If the requested sequence number is in use, then this device will * be allocated another one. * * Note that the device's seq value is not changed by this function. * * @dev: Device for which to allocate sequence number * @return sequence number allocated, or -ve on error */ int uclass_resolve_seq(struct udevice *dev); /** * 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