include/media/cec-notifier.h

   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 #else
  92 static inline struct cec_notifier *cec_notifier_get(struct device *dev)
  93 {
  94         /* A non-NULL pointer is expected on success */
  95         return (struct cec_notifier *)0xdeadfeed;
  96 }
  97
  98 static inline void cec_notifier_put(struct cec_notifier *n)
  99 {
 100 }
 101
 102 static inline void cec_notifier_set_phys_addr(struct cec_notifier *n, u16 pa)
 103 {
 104 }
 105
 106 static inline void cec_notifier_set_phys_addr_from_edid(struct cec_notifier *n,
 107                                                         const struct edid *edid)
 108 {
 109 }
 110
 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
 117 static inline void cec_notifier_unregister(struct cec_notifier *n)
 118 {
 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