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  */
component_match_add(struct device * master,struct component_match ** matchptr,int (* compare)(struct device *,void *),void * compare_data)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
126