xref: /openbmc/linux/include/media/cec-notifier.h (revision 4cff79e9)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * cec-notifier.h - notify CEC drivers of physical address changes
4  *
5  * Copyright 2016 Russell King <rmk+kernel@arm.linux.org.uk>
6  * Copyright 2016-2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
7  */
8 
9 #ifndef LINUX_CEC_NOTIFIER_H
10 #define LINUX_CEC_NOTIFIER_H
11 
12 #include <linux/types.h>
13 #include <media/cec.h>
14 
15 struct device;
16 struct edid;
17 struct cec_adapter;
18 struct cec_notifier;
19 
20 #if IS_REACHABLE(CONFIG_CEC_CORE) && IS_ENABLED(CONFIG_CEC_NOTIFIER)
21 
22 /**
23  * cec_notifier_get - find or create a new cec_notifier for the given device.
24  * @dev: device that sends the events.
25  *
26  * If a notifier for device @dev already exists, then increase the refcount
27  * and return that notifier.
28  *
29  * If it doesn't exist, then allocate a new notifier struct and return a
30  * pointer to that new struct.
31  *
32  * Return NULL if the memory could not be allocated.
33  */
34 struct cec_notifier *cec_notifier_get(struct device *dev);
35 
36 /**
37  * cec_notifier_put - decrease refcount and delete when the refcount reaches 0.
38  * @n: notifier
39  */
40 void cec_notifier_put(struct cec_notifier *n);
41 
42 /**
43  * cec_notifier_set_phys_addr - set a new physical address.
44  * @n: the CEC notifier
45  * @pa: the CEC physical address
46  *
47  * Set a new CEC physical address.
48  * Does nothing if @n == NULL.
49  */
50 void cec_notifier_set_phys_addr(struct cec_notifier *n, u16 pa);
51 
52 /**
53  * cec_notifier_set_phys_addr_from_edid - set parse the PA from the EDID.
54  * @n: the CEC notifier
55  * @edid: the struct edid pointer
56  *
57  * Parses the EDID to obtain the new CEC physical address and set it.
58  * Does nothing if @n == NULL.
59  */
60 void cec_notifier_set_phys_addr_from_edid(struct cec_notifier *n,
61 					  const struct edid *edid);
62 
63 /**
64  * cec_notifier_register - register a callback with the notifier
65  * @n: the CEC notifier
66  * @adap: the CEC adapter, passed as argument to the callback function
67  * @callback: the callback function
68  */
69 void cec_notifier_register(struct cec_notifier *n,
70 			   struct cec_adapter *adap,
71 			   void (*callback)(struct cec_adapter *adap, u16 pa));
72 
73 /**
74  * cec_notifier_unregister - unregister the callback from the notifier.
75  * @n: the CEC notifier
76  */
77 void cec_notifier_unregister(struct cec_notifier *n);
78 
79 /**
80  * cec_register_cec_notifier - register the notifier with the cec adapter.
81  * @adap: the CEC adapter
82  * @notifier: the CEC notifier
83  */
84 void cec_register_cec_notifier(struct cec_adapter *adap,
85 			       struct cec_notifier *notifier);
86 
87 #else
88 static inline struct cec_notifier *cec_notifier_get(struct device *dev)
89 {
90 	/* A non-NULL pointer is expected on success */
91 	return (struct cec_notifier *)0xdeadfeed;
92 }
93 
94 static inline void cec_notifier_put(struct cec_notifier *n)
95 {
96 }
97 
98 static inline void cec_notifier_set_phys_addr(struct cec_notifier *n, u16 pa)
99 {
100 }
101 
102 static inline void cec_notifier_set_phys_addr_from_edid(struct cec_notifier *n,
103 							const struct edid *edid)
104 {
105 }
106 
107 static inline void cec_notifier_register(struct cec_notifier *n,
108 			 struct cec_adapter *adap,
109 			 void (*callback)(struct cec_adapter *adap, u16 pa))
110 {
111 }
112 
113 static inline void cec_notifier_unregister(struct cec_notifier *n)
114 {
115 }
116 
117 static inline void cec_register_cec_notifier(struct cec_adapter *adap,
118 					     struct cec_notifier *notifier)
119 {
120 }
121 #endif
122 
123 /**
124  * cec_notifier_phys_addr_invalidate() - set the physical address to INVALID
125  *
126  * @n: the CEC notifier
127  *
128  * This is a simple helper function to invalidate the physical
129  * address. Does nothing if @n == NULL.
130  */
131 static inline void cec_notifier_phys_addr_invalidate(struct cec_notifier *n)
132 {
133 	cec_notifier_set_phys_addr(n, CEC_PHYS_ADDR_INVALID);
134 }
135 
136 #endif
137