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_conn - find or create a new cec_notifier for the given
24  * device and connector tuple.
25  * @dev: device that sends the events.
26  * @conn: the connector name from which the event occurs
27  *
28  * If a notifier for device @dev already exists, then increase the refcount
29  * and return that notifier.
30  *
31  * If it doesn't exist, then allocate a new notifier struct and return a
32  * pointer to that new struct.
33  *
34  * Return NULL if the memory could not be allocated.
35  */
36 struct cec_notifier *cec_notifier_get_conn(struct device *dev,
37 					   const char *conn);
38 
39 /**
40  * cec_notifier_put - decrease refcount and delete when the refcount reaches 0.
41  * @n: notifier
42  */
43 void cec_notifier_put(struct cec_notifier *n);
44 
45 /**
46  * cec_notifier_set_phys_addr - set a new physical address.
47  * @n: the CEC notifier
48  * @pa: the CEC physical address
49  *
50  * Set a new CEC physical address.
51  * Does nothing if @n == NULL.
52  */
53 void cec_notifier_set_phys_addr(struct cec_notifier *n, u16 pa);
54 
55 /**
56  * cec_notifier_set_phys_addr_from_edid - set parse the PA from the EDID.
57  * @n: the CEC notifier
58  * @edid: the struct edid pointer
59  *
60  * Parses the EDID to obtain the new CEC physical address and set it.
61  * Does nothing if @n == NULL.
62  */
63 void cec_notifier_set_phys_addr_from_edid(struct cec_notifier *n,
64 					  const struct edid *edid);
65 
66 /**
67  * cec_notifier_register - register a callback with the notifier
68  * @n: the CEC notifier
69  * @adap: the CEC adapter, passed as argument to the callback function
70  * @callback: the callback function
71  */
72 void cec_notifier_register(struct cec_notifier *n,
73 			   struct cec_adapter *adap,
74 			   void (*callback)(struct cec_adapter *adap, u16 pa));
75 
76 /**
77  * cec_notifier_unregister - unregister the callback from the notifier.
78  * @n: the CEC notifier
79  */
80 void cec_notifier_unregister(struct cec_notifier *n);
81 
82 /**
83  * cec_register_cec_notifier - register the notifier with the cec adapter.
84  * @adap: the CEC adapter
85  * @notifier: the CEC notifier
86  */
87 void cec_register_cec_notifier(struct cec_adapter *adap,
88 			       struct cec_notifier *notifier);
89 
90 #else
cec_notifier_get_conn(struct device * dev,const char * conn)91 static inline struct cec_notifier *cec_notifier_get_conn(struct device *dev,
92 							 const char *conn)
93 {
94 	/* A non-NULL pointer is expected on success */
95 	return (struct cec_notifier *)0xdeadfeed;
96 }
97 
cec_notifier_put(struct cec_notifier * n)98 static inline void cec_notifier_put(struct cec_notifier *n)
99 {
100 }
101 
cec_notifier_set_phys_addr(struct cec_notifier * n,u16 pa)102 static inline void cec_notifier_set_phys_addr(struct cec_notifier *n, u16 pa)
103 {
104 }
105 
cec_notifier_set_phys_addr_from_edid(struct cec_notifier * n,const struct edid * edid)106 static inline void cec_notifier_set_phys_addr_from_edid(struct cec_notifier *n,
107 							const struct edid *edid)
108 {
109 }
110 
cec_notifier_register(struct cec_notifier * n,struct cec_adapter * adap,void (* callback)(struct cec_adapter * adap,u16 pa))111 static inline void cec_notifier_register(struct cec_notifier *n,
112 			 struct cec_adapter *adap,
113 			 void (*callback)(struct cec_adapter *adap, u16 pa))
114 {
115 }
116 
cec_notifier_unregister(struct cec_notifier * n)117 static inline void cec_notifier_unregister(struct cec_notifier *n)
118 {
119 }
120 
cec_register_cec_notifier(struct cec_adapter * adap,struct cec_notifier * notifier)121 static inline void cec_register_cec_notifier(struct cec_adapter *adap,
122 					     struct cec_notifier *notifier)
123 {
124 }
125 #endif
126 
127 /**
128  * cec_notifier_get - find or create a new cec_notifier for the given device.
129  * @dev: device that sends the events.
130  *
131  * If a notifier for device @dev already exists, then increase the refcount
132  * and return that notifier.
133  *
134  * If it doesn't exist, then allocate a new notifier struct and return a
135  * pointer to that new struct.
136  *
137  * Return NULL if the memory could not be allocated.
138  */
cec_notifier_get(struct device * dev)139 static inline struct cec_notifier *cec_notifier_get(struct device *dev)
140 {
141 	return cec_notifier_get_conn(dev, NULL);
142 }
143 
144 /**
145  * cec_notifier_phys_addr_invalidate() - set the physical address to INVALID
146  *
147  * @n: the CEC notifier
148  *
149  * This is a simple helper function to invalidate the physical
150  * address. Does nothing if @n == NULL.
151  */
cec_notifier_phys_addr_invalidate(struct cec_notifier * n)152 static inline void cec_notifier_phys_addr_invalidate(struct cec_notifier *n)
153 {
154 	cec_notifier_set_phys_addr(n, CEC_PHYS_ADDR_INVALID);
155 }
156 
157 #endif
158