| /* |
| * 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 <linker_lists.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; |
| |
| /* 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 |