1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef COMPONENT_H
3 #define COMPONENT_H
4
5 #include <linux/stddef.h>
6
7
8 struct device;
9
10 /**
11 * struct component_ops - callbacks for component drivers
12 *
13 * Components are registered with component_add() and unregistered with
14 * component_del().
15 */
16 struct component_ops {
17 /**
18 * @bind:
19 *
20 * Called through component_bind_all() when the aggregate driver is
21 * ready to bind the overall driver.
22 */
23 int (*bind)(struct device *comp, struct device *master,
24 void *master_data);
25 /**
26 * @unbind:
27 *
28 * Called through component_unbind_all() when the aggregate driver is
29 * ready to bind the overall driver, or when component_bind_all() fails
30 * part-ways through and needs to unbind some already bound components.
31 */
32 void (*unbind)(struct device *comp, struct device *master,
33 void *master_data);
34 };
35
36 int component_add(struct device *, const struct component_ops *);
37 int component_add_typed(struct device *dev, const struct component_ops *ops,
38 int subcomponent);
39 void component_del(struct device *, const struct component_ops *);
40
41 int component_bind_all(struct device *master, void *master_data);
42 void component_unbind_all(struct device *master, void *master_data);
43
44 struct master;
45
46 /**
47 * struct component_master_ops - callback for the aggregate driver
48 *
49 * Aggregate drivers are registered with component_master_add_with_match() and
50 * unregistered with component_master_del().
51 */
52 struct component_master_ops {
53 /**
54 * @bind:
55 *
56 * Called when all components or the aggregate driver, as specified in
57 * the match list passed to component_master_add_with_match(), are
58 * ready. Usually there are 3 steps to bind an aggregate driver:
59 *
60 * 1. Allocate a structure for the aggregate driver.
61 *
62 * 2. Bind all components to the aggregate driver by calling
63 * component_bind_all() with the aggregate driver structure as opaque
64 * pointer data.
65 *
66 * 3. Register the aggregate driver with the subsystem to publish its
67 * interfaces.
68 *
69 * Note that the lifetime of the aggregate driver does not align with
70 * any of the underlying &struct device instances. Therefore devm cannot
71 * be used and all resources acquired or allocated in this callback must
72 * be explicitly released in the @unbind callback.
73 */
74 int (*bind)(struct device *master);
75 /**
76 * @unbind:
77 *
78 * Called when either the aggregate driver, using
79 * component_master_del(), or one of its components, using
80 * component_del(), is unregistered.
81 */
82 void (*unbind)(struct device *master);
83 };
84
85 void component_master_del(struct device *,
86 const struct component_master_ops *);
87
88 struct component_match;
89
90 int component_master_add_with_match(struct device *,
91 const struct component_master_ops *, struct component_match *);
92 void component_match_add_release(struct device *master,
93 struct component_match **matchptr,
94 void (*release)(struct device *, void *),
95 int (*compare)(struct device *, void *), void *compare_data);
96 void component_match_add_typed(struct device *master,
97 struct component_match **matchptr,
98 int (*compare_typed)(struct device *, int, void *), void *compare_data);
99
100 /**
101 * component_match_add - add a component match entry
102 * @master: device with the aggregate driver
103 * @matchptr: pointer to the list of component matches
104 * @compare: compare function to match against all components
105 * @compare_data: opaque pointer passed to the @compare function
106 *
107 * Adds a new component match to the list stored in @matchptr, which the @master
108 * aggregate driver needs to function. The list of component matches pointed to
109 * by @matchptr must be initialized to NULL before adding the first match. This
110 * only matches against components added with component_add().
111 *
112 * The allocated match list in @matchptr is automatically released using devm
113 * actions.
114 *
115 * See also component_match_add_release() and component_match_add_typed().
116 */
117 static inline void component_match_add(struct device *master,
118 struct component_match **matchptr,
119 int (*compare)(struct device *, void *), void *compare_data)
120 {
121 component_match_add_release(master, matchptr, NULL, compare,
122 compare_data);
123 }
124
125 #endif