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 void component_del(struct device *, const struct component_ops *); 38 39 int component_bind_all(struct device *master, void *master_data); 40 void component_unbind_all(struct device *master, void *master_data); 41 42 struct master; 43 44 /** 45 * struct component_master_ops - callback for the aggregate driver 46 * 47 * Aggregate drivers are registered with component_master_add_with_match() and 48 * unregistered with component_master_del(). 49 */ 50 struct component_master_ops { 51 /** 52 * @bind: 53 * 54 * Called when all components or the aggregate driver, as specified in 55 * the match list passed to component_master_add_with_match(), are 56 * ready. Usually there are 3 steps to bind an aggregate driver: 57 * 58 * 1. Allocate a structure for the aggregate driver. 59 * 60 * 2. Bind all components to the aggregate driver by calling 61 * component_bind_all() with the aggregate driver structure as opaque 62 * pointer data. 63 * 64 * 3. Register the aggregate driver with the subsystem to publish its 65 * interfaces. 66 * 67 * Note that the lifetime of the aggregate driver does not align with 68 * any of the underlying &struct device instances. Therefore devm cannot 69 * be used and all resources acquired or allocated in this callback must 70 * be explicitly released in the @unbind callback. 71 */ 72 int (*bind)(struct device *master); 73 /** 74 * @unbind: 75 * 76 * Called when either the aggregate driver, using 77 * component_master_del(), or one of its components, using 78 * component_del(), is unregistered. 79 */ 80 void (*unbind)(struct device *master); 81 }; 82 83 void component_master_del(struct device *, 84 const struct component_master_ops *); 85 86 struct component_match; 87 88 int component_master_add_with_match(struct device *, 89 const struct component_master_ops *, struct component_match *); 90 void component_match_add_release(struct device *master, 91 struct component_match **matchptr, 92 void (*release)(struct device *, void *), 93 int (*compare)(struct device *, void *), void *compare_data); 94 95 /** 96 * component_match_add - add a compent match 97 * @master: device with the aggregate driver 98 * @matchptr: pointer to the list of component matches 99 * @compare: compare function to match against all components 100 * @compare_data: opaque pointer passed to the @compare function 101 * 102 * Adds a new component match to the list stored in @matchptr, which the @master 103 * aggregate driver needs to function. The list of component matches pointed to 104 * by @matchptr must be initialized to NULL before adding the first match. 105 * 106 * The allocated match list in @matchptr is automatically released using devm 107 * actions. 108 * 109 * See also component_match_add_release(). 110 */ 111 static inline void component_match_add(struct device *master, 112 struct component_match **matchptr, 113 int (*compare)(struct device *, void *), void *compare_data) 114 { 115 component_match_add_release(master, matchptr, NULL, compare, 116 compare_data); 117 } 118 119 #endif 120