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Simon Glass6494d702014-02-26 15:59:18 -07001/*
2 * Copyright (c) 2013 Google, Inc
3 *
4 * (C) Copyright 2012
5 * Pavel Herrmann <morpheus.ibis@gmail.com>
6 *
7 * SPDX-License-Identifier: GPL-2.0+
8 */
9
10#ifndef _DM_UCLASS_H
11#define _DM_UCLASS_H
12
13#include <dm/uclass-id.h>
Masahiro Yamada42c23dd2014-10-07 14:49:13 +090014#include <linker_lists.h>
Simon Glass6494d702014-02-26 15:59:18 -070015#include <linux/list.h>
16
17/**
18 * struct uclass - a U-Boot drive class, collecting together similar drivers
19 *
20 * A uclass provides an interface to a particular function, which is
21 * implemented by one or more drivers. Every driver belongs to a uclass even
22 * if it is the only driver in that uclass. An example uclass is GPIO, which
23 * provides the ability to change read inputs, set and clear outputs, etc.
24 * There may be drivers for on-chip SoC GPIO banks, I2C GPIO expanders and
25 * PMIC IO lines, all made available in a unified way through the uclass.
26 *
27 * @priv: Private data for this uclass
28 * @uc_drv: The driver for the uclass itself, not to be confused with a
29 * 'struct driver'
Simon Glassf2bc6fc2014-06-11 23:29:54 -060030 * @dev_head: List of devices in this uclass (devices are attached to their
Simon Glass6494d702014-02-26 15:59:18 -070031 * uclass when their bind method is called)
32 * @sibling_node: Next uclass in the linked list of uclasses
33 */
34struct uclass {
35 void *priv;
36 struct uclass_driver *uc_drv;
37 struct list_head dev_head;
38 struct list_head sibling_node;
39};
40
Heiko Schocher54c5d082014-05-22 12:43:05 +020041struct udevice;
Simon Glass6494d702014-02-26 15:59:18 -070042
43/**
44 * struct uclass_driver - Driver for the uclass
45 *
46 * A uclass_driver provides a consistent interface to a set of related
47 * drivers.
48 *
49 * @name: Name of uclass driver
50 * @id: ID number of this uclass
51 * @post_bind: Called after a new device is bound to this uclass
52 * @pre_unbind: Called before a device is unbound from this uclass
53 * @post_probe: Called after a new device is probed
54 * @pre_remove: Called before a device is removed
55 * @init: Called to set up the uclass
56 * @destroy: Called to destroy the uclass
57 * @priv_auto_alloc_size: If non-zero this is the size of the private data
58 * to be allocated in the uclass's ->priv pointer. If zero, then the uclass
59 * driver is responsible for allocating any data required.
60 * @per_device_auto_alloc_size: Each device can hold private data owned
61 * by the uclass. If required this will be automatically allocated if this
62 * value is non-zero.
63 * @ops: Uclass operations, providing the consistent interface to devices
64 * within the uclass.
65 */
66struct uclass_driver {
67 const char *name;
68 enum uclass_id id;
Heiko Schocher54c5d082014-05-22 12:43:05 +020069 int (*post_bind)(struct udevice *dev);
70 int (*pre_unbind)(struct udevice *dev);
71 int (*post_probe)(struct udevice *dev);
72 int (*pre_remove)(struct udevice *dev);
Simon Glass6494d702014-02-26 15:59:18 -070073 int (*init)(struct uclass *class);
74 int (*destroy)(struct uclass *class);
75 int priv_auto_alloc_size;
76 int per_device_auto_alloc_size;
77 const void *ops;
78};
79
80/* Declare a new uclass_driver */
81#define UCLASS_DRIVER(__name) \
82 ll_entry_declare(struct uclass_driver, __name, uclass)
83
84/**
85 * uclass_get() - Get a uclass based on an ID, creating it if needed
86 *
87 * Every uclass is identified by an ID, a number from 0 to n-1 where n is
88 * the number of uclasses. This function allows looking up a uclass by its
89 * ID.
90 *
91 * @key: ID to look up
92 * @ucp: Returns pointer to uclass (there is only one per ID)
93 * @return 0 if OK, -ve on error
94 */
95int uclass_get(enum uclass_id key, struct uclass **ucp);
96
97/**
98 * uclass_get_device() - Get a uclass device based on an ID and index
99 *
Simon Glassf2bc6fc2014-06-11 23:29:54 -0600100 * The device is probed to activate it ready for use.
101 *
Simon Glass0040b942014-07-23 06:55:17 -0600102 * @id: ID to look up
Simon Glass6494d702014-02-26 15:59:18 -0700103 * @index: Device number within that uclass (0=first)
Simon Glassf2bc6fc2014-06-11 23:29:54 -0600104 * @devp: Returns pointer to device (there is only one per for each ID)
Simon Glass6494d702014-02-26 15:59:18 -0700105 * @return 0 if OK, -ve on error
106 */
Simon Glassf2bc6fc2014-06-11 23:29:54 -0600107int uclass_get_device(enum uclass_id id, int index, struct udevice **devp);
Simon Glass6494d702014-02-26 15:59:18 -0700108
109/**
Simon Glass5a66a8f2014-07-23 06:55:12 -0600110 * uclass_get_device_by_seq() - Get a uclass device based on an ID and sequence
111 *
112 * If an active device has this sequence it will be returned. If there is no
113 * such device then this will check for a device that is requesting this
114 * sequence.
115 *
116 * The device is probed to activate it ready for use.
117 *
118 * @id: ID to look up
119 * @seq: Sequence number to find (0=first)
120 * @devp: Returns pointer to device (there is only one for each seq)
121 * @return 0 if OK, -ve on error
122 */
123int uclass_get_device_by_seq(enum uclass_id id, int seq, struct udevice **devp);
124
125/**
Simon Glassf4cdead2014-07-23 06:55:14 -0600126 * uclass_get_device_by_of_offset() - Get a uclass device by device tree node
127 *
128 * This searches the devices in the uclass for one attached to the given
129 * device tree node.
130 *
131 * The device is probed to activate it ready for use.
132 *
133 * @id: ID to look up
134 * @node: Device tree offset to search for (if -ve then -ENODEV is returned)
135 * @devp: Returns pointer to device (there is only one for each node)
136 * @return 0 if OK, -ve on error
137 */
138int uclass_get_device_by_of_offset(enum uclass_id id, int node,
139 struct udevice **devp);
140
141/**
Simon Glass6494d702014-02-26 15:59:18 -0700142 * uclass_first_device() - Get the first device in a uclass
143 *
144 * @id: Uclass ID to look up
145 * @devp: Returns pointer to the first device in that uclass, or NULL if none
146 * @return 0 if OK (found or not found), -1 on error
147 */
Heiko Schocher54c5d082014-05-22 12:43:05 +0200148int uclass_first_device(enum uclass_id id, struct udevice **devp);
Simon Glass6494d702014-02-26 15:59:18 -0700149
150/**
151 * uclass_next_device() - Get the next device in a uclass
152 *
153 * @devp: On entry, pointer to device to lookup. On exit, returns pointer
154 * to the next device in the same uclass, or NULL if none
155 * @return 0 if OK (found or not found), -1 on error
156 */
Heiko Schocher54c5d082014-05-22 12:43:05 +0200157int uclass_next_device(struct udevice **devp);
Simon Glass6494d702014-02-26 15:59:18 -0700158
159/**
Simon Glass5a66a8f2014-07-23 06:55:12 -0600160 * uclass_resolve_seq() - Resolve a device's sequence number
161 *
162 * On entry dev->seq is -1, and dev->req_seq may be -1 (to allocate a
163 * sequence number automatically, or >= 0 to select a particular number.
164 * If the requested sequence number is in use, then this device will
165 * be allocated another one.
166 *
167 * Note that the device's seq value is not changed by this function.
168 *
169 * @dev: Device for which to allocate sequence number
170 * @return sequence number allocated, or -ve on error
171 */
172int uclass_resolve_seq(struct udevice *dev);
173
174/**
Simon Glass6494d702014-02-26 15:59:18 -0700175 * uclass_foreach_dev() - Helper function to iteration through devices
176 *
177 * This creates a for() loop which works through the available devices in
178 * a uclass in order from start to end.
179 *
Heiko Schocher54c5d082014-05-22 12:43:05 +0200180 * @pos: struct udevice * to hold the current device. Set to NULL when there
Simon Glass6494d702014-02-26 15:59:18 -0700181 * are no more devices.
Simon Glassf2bc6fc2014-06-11 23:29:54 -0600182 * @uc: uclass to scan
Simon Glass6494d702014-02-26 15:59:18 -0700183 */
184#define uclass_foreach_dev(pos, uc) \
185 for (pos = list_entry((&(uc)->dev_head)->next, typeof(*pos), \
186 uclass_node); \
187 prefetch(pos->uclass_node.next), \
188 &pos->uclass_node != (&(uc)->dev_head); \
189 pos = list_entry(pos->uclass_node.next, typeof(*pos), \
190 uclass_node))
191
192#endif