xref: /openbmc/linux/include/media/cec-notifier.h (revision dc6a81c3)
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/err.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_conn_register - find or create a new cec_notifier for the given
41  * HDMI device and connector tuple.
42  * @hdmi_dev: HDMI device that sends the events.
43  * @conn_name: the connector name from which the event occurs. May be NULL
44  * if there is always only one HDMI connector created by the HDMI device.
45  * @conn_info: the connector info from which the event occurs (may be NULL)
46  *
47  * If a notifier for device @dev and connector @conn_name already exists, then
48  * increase the refcount and return that notifier.
49  *
50  * If it doesn't exist, then allocate a new notifier struct and return a
51  * pointer to that new struct.
52  *
53  * Return NULL if the memory could not be allocated.
54  */
55 struct cec_notifier *
56 cec_notifier_conn_register(struct device *hdmi_dev, const char *conn_name,
57 			   const struct cec_connector_info *conn_info);
58 
59 /**
60  * cec_notifier_conn_unregister - decrease refcount and delete when the
61  * refcount reaches 0.
62  * @n: notifier. If NULL, then this function does nothing.
63  */
64 void cec_notifier_conn_unregister(struct cec_notifier *n);
65 
66 /**
67  * cec_notifier_cec_adap_register - find or create a new cec_notifier for the
68  * given device.
69  * @hdmi_dev: HDMI device that sends the events.
70  * @conn_name: the connector name from which the event occurs. May be NULL
71  * if there is always only one HDMI connector created by the HDMI device.
72  * @adap: the cec adapter that registered this notifier.
73  *
74  * If a notifier for device @dev and connector @conn_name already exists, then
75  * increase the refcount and return that notifier.
76  *
77  * If it doesn't exist, then allocate a new notifier struct and return a
78  * pointer to that new struct.
79  *
80  * Return NULL if the memory could not be allocated.
81  */
82 struct cec_notifier *
83 cec_notifier_cec_adap_register(struct device *hdmi_dev, const char *conn_name,
84 			       struct cec_adapter *adap);
85 
86 /**
87  * cec_notifier_cec_adap_unregister - decrease refcount and delete when the
88  * refcount reaches 0.
89  * @n: notifier. If NULL, then this function does nothing.
90  * @adap: the cec adapter that registered this notifier.
91  */
92 void cec_notifier_cec_adap_unregister(struct cec_notifier *n,
93 				      struct cec_adapter *adap);
94 
95 /**
96  * cec_notifier_set_phys_addr - set a new physical address.
97  * @n: the CEC notifier
98  * @pa: the CEC physical address
99  *
100  * Set a new CEC physical address.
101  * Does nothing if @n == NULL.
102  */
103 void cec_notifier_set_phys_addr(struct cec_notifier *n, u16 pa);
104 
105 /**
106  * cec_notifier_set_phys_addr_from_edid - set parse the PA from the EDID.
107  * @n: the CEC notifier
108  * @edid: the struct edid pointer
109  *
110  * Parses the EDID to obtain the new CEC physical address and set it.
111  * Does nothing if @n == NULL.
112  */
113 void cec_notifier_set_phys_addr_from_edid(struct cec_notifier *n,
114 					  const struct edid *edid);
115 
116 /**
117  * cec_notifier_parse_hdmi_phandle - find the hdmi device from "hdmi-phandle"
118  * @dev: the device with the "hdmi-phandle" device tree property
119  *
120  * Returns the device pointer referenced by the "hdmi-phandle" property.
121  * Note that the refcount of the returned device is not incremented.
122  * This device pointer is only used as a key value in the notifier
123  * list, but it is never accessed by the CEC driver.
124  */
125 struct device *cec_notifier_parse_hdmi_phandle(struct device *dev);
126 
127 #else
128 static inline struct cec_notifier *cec_notifier_get_conn(struct device *dev,
129 							 const char *conn)
130 {
131 	/* A non-NULL pointer is expected on success */
132 	return (struct cec_notifier *)0xdeadfeed;
133 }
134 
135 static inline struct cec_notifier *
136 cec_notifier_conn_register(struct device *hdmi_dev, const char *conn_name,
137 			   const struct cec_connector_info *conn_info)
138 {
139 	/* A non-NULL pointer is expected on success */
140 	return (struct cec_notifier *)0xdeadfeed;
141 }
142 
143 static inline void cec_notifier_conn_unregister(struct cec_notifier *n)
144 {
145 }
146 
147 static inline struct cec_notifier *
148 cec_notifier_cec_adap_register(struct device *hdmi_dev, const char *conn_name,
149 			       struct cec_adapter *adap)
150 {
151 	/* A non-NULL pointer is expected on success */
152 	return (struct cec_notifier *)0xdeadfeed;
153 }
154 
155 static inline void cec_notifier_cec_adap_unregister(struct cec_notifier *n,
156 						    struct cec_adapter *adap)
157 {
158 }
159 
160 static inline void cec_notifier_set_phys_addr(struct cec_notifier *n, u16 pa)
161 {
162 }
163 
164 static inline void cec_notifier_set_phys_addr_from_edid(struct cec_notifier *n,
165 							const struct edid *edid)
166 {
167 }
168 
169 static inline struct device *cec_notifier_parse_hdmi_phandle(struct device *dev)
170 {
171 	return ERR_PTR(-ENODEV);
172 }
173 
174 #endif
175 
176 /**
177  * cec_notifier_phys_addr_invalidate() - set the physical address to INVALID
178  *
179  * @n: the CEC notifier
180  *
181  * This is a simple helper function to invalidate the physical
182  * address. Does nothing if @n == NULL.
183  */
184 static inline void cec_notifier_phys_addr_invalidate(struct cec_notifier *n)
185 {
186 	cec_notifier_set_phys_addr(n, CEC_PHYS_ADDR_INVALID);
187 }
188 
189 #endif
190