include/linux/component.h

   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