xref: /openbmc/linux/include/media/cec-notifier.h (revision d3964221)
1 /*
2  * cec-notifier.h - notify CEC drivers of physical address changes
3  *
4  * Copyright 2016 Russell King <rmk+kernel@arm.linux.org.uk>
5  * Copyright 2016-2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
6  *
7  * This program is free software; you may redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; version 2 of the License.
10  *
11  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
12  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
13  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
14  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
15  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
16  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
17  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
18  * SOFTWARE.
19  */
20 
21 #ifndef LINUX_CEC_NOTIFIER_H
22 #define LINUX_CEC_NOTIFIER_H
23 
24 #include <linux/types.h>
25 #include <media/cec.h>
26 
27 struct device;
28 struct edid;
29 struct cec_adapter;
30 struct cec_notifier;
31 
32 #if IS_REACHABLE(CONFIG_CEC_CORE) && IS_ENABLED(CONFIG_CEC_NOTIFIER)
33 
34 /**
35  * cec_notifier_get - find or create a new cec_notifier for the given device.
36  * @dev: device that sends the events.
37  *
38  * If a notifier for device @dev already exists, then increase the refcount
39  * and return that notifier.
40  *
41  * If it doesn't exist, then allocate a new notifier struct and return a
42  * pointer to that new struct.
43  *
44  * Return NULL if the memory could not be allocated.
45  */
46 struct cec_notifier *cec_notifier_get(struct device *dev);
47 
48 /**
49  * cec_notifier_put - decrease refcount and delete when the refcount reaches 0.
50  * @n: notifier
51  */
52 void cec_notifier_put(struct cec_notifier *n);
53 
54 /**
55  * cec_notifier_set_phys_addr - set a new physical address.
56  * @n: the CEC notifier
57  * @pa: the CEC physical address
58  *
59  * Set a new CEC physical address.
60  * Does nothing if @n == NULL.
61  */
62 void cec_notifier_set_phys_addr(struct cec_notifier *n, u16 pa);
63 
64 /**
65  * cec_notifier_set_phys_addr_from_edid - set parse the PA from the EDID.
66  * @n: the CEC notifier
67  * @edid: the struct edid pointer
68  *
69  * Parses the EDID to obtain the new CEC physical address and set it.
70  * Does nothing if @n == NULL.
71  */
72 void cec_notifier_set_phys_addr_from_edid(struct cec_notifier *n,
73 					  const struct edid *edid);
74 
75 /**
76  * cec_notifier_register - register a callback with the notifier
77  * @n: the CEC notifier
78  * @adap: the CEC adapter, passed as argument to the callback function
79  * @callback: the callback function
80  */
81 void cec_notifier_register(struct cec_notifier *n,
82 			   struct cec_adapter *adap,
83 			   void (*callback)(struct cec_adapter *adap, u16 pa));
84 
85 /**
86  * cec_notifier_unregister - unregister the callback from the notifier.
87  * @n: the CEC notifier
88  */
89 void cec_notifier_unregister(struct cec_notifier *n);
90 
91 /**
92  * cec_register_cec_notifier - register the notifier with the cec adapter.
93  * @adap: the CEC adapter
94  * @notifier: the CEC notifier
95  */
96 void cec_register_cec_notifier(struct cec_adapter *adap,
97 			       struct cec_notifier *notifier);
98 
99 #else
100 static inline struct cec_notifier *cec_notifier_get(struct device *dev)
101 {
102 	/* A non-NULL pointer is expected on success */
103 	return (struct cec_notifier *)0xdeadfeed;
104 }
105 
106 static inline void cec_notifier_put(struct cec_notifier *n)
107 {
108 }
109 
110 static inline void cec_notifier_set_phys_addr(struct cec_notifier *n, u16 pa)
111 {
112 }
113 
114 static inline void cec_notifier_set_phys_addr_from_edid(struct cec_notifier *n,
115 							const struct edid *edid)
116 {
117 }
118 
119 static inline void cec_notifier_register(struct cec_notifier *n,
120 			 struct cec_adapter *adap,
121 			 void (*callback)(struct cec_adapter *adap, u16 pa))
122 {
123 }
124 
125 static inline void cec_notifier_unregister(struct cec_notifier *n)
126 {
127 }
128 
129 static inline void cec_register_cec_notifier(struct cec_adapter *adap,
130 					     struct cec_notifier *notifier)
131 {
132 }
133 #endif
134 
135 /**
136  * cec_notifier_phys_addr_invalidate() - set the physical address to INVALID
137  *
138  * @n: the CEC notifier
139  *
140  * This is a simple helper function to invalidate the physical
141  * address. Does nothing if @n == NULL.
142  */
143 static inline void cec_notifier_phys_addr_invalidate(struct cec_notifier *n)
144 {
145 	cec_notifier_set_phys_addr(n, CEC_PHYS_ADDR_INVALID);
146 }
147 
148 #endif
149